MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Journal of Biochemistry' source. Thu, 09 Feb 2012 13:38:36 +0100 http://www.medworm.com/index.php?rid=5635119&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F205%3Frss%3D1 Cancer cells undergo epithelial-mesenchymal transition (EMT) during invasion and metastasis. Although transforming growth factor-β (TGF-β) and pro-inflammatory cytokines have been implicated in EMT, the underlying molecular mechanisms remain to be elucidated. Here, we studied the effects of proinflammatory cytokines derived from the mouse macrophage cell line RAW 264.7 on TGF-β-induced EMT in A549 lung cancer cells. Co-culture and treatment with conditioned medium of RAW 264.7 cells enhanced a subset of TGF-β-induced EMT phenotypes in A549 cells, including changes in cell morphology and induction of mesenchymal marker expression. These effects were increased by the treatment of RAW 264.7 cells with lipopolysaccharide, which also induced the expression of various proinfl... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635119 Wed, 25 Jan 2012 05:00:00 +0100 5635119 http://www.medworm.com/index.php?rid=5635118&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F197%3Frss%3D1 All cloned sialyltransferases from vertebrates are classified into four subfamilies and are characterized as having type II transmembrane topology. The catalytic domain has highly conserved motifs known as sialylmotifs. Besides sialylmotifs, each family has several unique conserved cysteine (Cys) residues mainly in the catalytic domain. The number and loci of conserved amino acids, however, differ with each subfamily, suggesting that the conserved Cys-residues and/or disulphide linkages they make may contribute to linkage specificity. Using Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF)-mass spectrometry, the present study performed disulphide linkage analysis on soluble mouse ST6Gal-I, which has six Cys-residues. Results confirmed that there were ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635118 Wed, 25 Jan 2012 05:00:00 +0100 5635118 http://www.medworm.com/index.php?rid=5635117&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F189%3Frss%3D1 Membrane spanning regions can be used as markers for studying the robustness of biologically important units of proteins against evolutionary change (R. Sawada and S. Mitaku, Genes to Cells, 2010). We carried out computational experiments of extensive DNA mutations on the assumption of constant GC content or constant codon positional nucleotide biases. Randomized sequences were evaluated by membrane protein prediction systems SOSUI and SOSUIsignal. When all amino acid sequences from the total real genomes of 538 prokaryotes were analysed, ratios of membrane proteins to all genes in the total genomes were almost constant around a ratio of 22% with a standard deviation of 1.56. When the nucleotide sequences were randomized, keeping only the GC contents constant, the ratios of membrane protei... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635117 Wed, 25 Jan 2012 05:00:00 +0100 5635117 http://www.medworm.com/index.php?rid=5635116&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F179%3Frss%3D1 In this study, we examined effects of HAI-1 on the protease activity and proteolytic activation of human airway trypsin-like protease (HAT), a transmembrane serine protease that is expressed mainly in bronchial epithelial cells. A soluble form of HAI-1 inhibited the protease activity of HAT in vitro. HAT was proteolytically activated in cultured mammalian cells transfected with its expression vector, and a soluble form of active HAT was released into the conditioned medium. The proteolytic activation of HAT required its own serine protease activity. Co-expression of the transmembrane full-length HAI-1 inhibited the proteolytic activation of HAT. In addition, full-length HAI-1 associated with the transmembrane full-length HAT in co-expressing cells. Like other target proteases of HAI-1, HAT... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635116 Wed, 25 Jan 2012 05:00:00 +0100 5635116 http://www.medworm.com/index.php?rid=5635115&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F167%3Frss%3D1 Copper amine oxidases (CAOs) catalyse the oxidation of various aliphatic amines to the corresponding aldehydes, ammonia and hydrogen peroxide. Although CAOs from various organisms share a highly conserved active-site structure including a protein-derived cofactor, topa quinone (TPQ), their substrate specificities differ considerably. To obtain structural insights into the substrate specificity of a CAO from Arthrobacter globiformis (AGAO), we have determined the X-ray crystal structures of AGAO complexed with irreversible inhibitors that form covalent adducts with TPQ. Three hydrazine derivatives, benzylhydrazine (BHZ), 4-hydroxybenzylhydrazine (4-OH-BHZ) and phenylhydrazine (PHZ) formed predominantly a hydrazone adduct, which is structurally analogous to the substrate Schiff base of TPQ f... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635115 Wed, 25 Jan 2012 05:00:00 +0100 5635115 http://www.medworm.com/index.php?rid=5635114&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F157%3Frss%3D1 Transforming growth factor β-activated protein kinase 1 (TAK1)-binding protein 2 (TAB2) and its close homolog TAB3 are initially characterized as adapter proteins essential for TAK1 activation in response to interleukin-1β and tumour necrosis factor-α. However, the physiological roles of TAB2 and TAB3 are still not fully understood. Here we report that TAB2 and TAB3 bind to Beclin1 and colocalize in the cytoplasm. TAB2 also interacts with ATG13 and is phosphorylated by ULK1. Overexpression of TAB2 or TAB3 induces punctate localization of ATG5 under the normal culture condition. Knockdown of TAB2 and TAB3 results in the decrease in endogenous protein level of p62/SQSTM1 under the normal culture condition, while overexpression of TAB2 results in the accumulation of p62/SQSTM1... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635114 Wed, 25 Jan 2012 05:00:00 +0100 5635114 http://www.medworm.com/index.php?rid=5635113&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F145%3Frss%3D1 Endothelial–mesenchymal transition (EndMT) plays important roles in various physiological and pathological processes. While signals mediated by transforming growth factor (TGF)-β have been implicated in EndMT, the molecular mechanisms underlying it remain to be fully elucidated. Here, we examined the effects of TGF-β signals on the EndMT of mouse pancreatic microvascular endothelial cells (MS-1). By addition of TGF-β2, MS-1 cells underwent mesenchymal transition characterized by re-organization of actin stress fibre and increased expression of various mesenchymal markers such as α-smooth muscle actin (α-SMA) through activation of Rho signals. Whereas activation of Rho signals via TGF-β-induced non-Smad signals has been implicated in epithelial–me... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635113 Wed, 25 Jan 2012 05:00:00 +0100 5635113 http://www.medworm.com/index.php?rid=5635112&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F139%3Frss%3D1 Terf/TRIM17 is a tripartite motif protein that has been originally isolated from testis. Terf has been characterized to exhibit an E3 ubiquitin ligase activity and to undergo self-ubiquitination. The cellular function of terf and its substrates, however, remain elusive. In the present study, we performed a yeast two-hybrid screening assay using terf as bait and identified a positive clone coding for ZW10 interacting protein (ZWINT), a known component of the kinetochore complex required for the mitotic spindle checkpoint. Immunoprecipitation and western blot analyses showed that terf interacted with ZWINT and that overexpression of terf caused down-regulation of protein levels of ZWINT in mammalian cells. In addition, the coiled-coil domain of terf was required for the interaction with ZWIN... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635112 Wed, 25 Jan 2012 05:00:00 +0100 5635112 http://www.medworm.com/index.php?rid=5635111&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F129%3Frss%3D1 The antibiotic heliquinomycin inhibited cellular DNA replication at IC50 of 2.5 µM without affecting level of chromatin-bound MCM4 and without activating the DNA replication stress checkpoint system, suggesting that heliquinomycin perturbs DNA replication mainly by inhibiting the activity of replicative DNA helicase that unwinds DNA duplex at replication forks. Among the DNA helicases involved in DNA replication, DNA helicase B was inhibited by heliquinomycin at IC50 of 4.3 µM and RECQL4 helicase at IC50 of 14 µM; these values are higher than that of MCM4/6/7 helicase (2.5 µM). These results suggest that heliquinomycin mainly targets actions of the replicative DNA helicases. Gel-retardation experiment indicates that heliquinomycin binds to single-stranded DNA. The s... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635111 Wed, 25 Jan 2012 05:00:00 +0100 5635111 http://www.medworm.com/index.php?rid=5635110&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F119%3Frss%3D1 Ghrelin is a stomach hormone that acts as an endogenous ligand of orphan G-protein-coupled receptor. Ghrelin is a 28-amino acid peptide existing in two major forms: n-octanoyl-modified ghrelin, which possesses an n-octanoyl modification on serine-3 and des-acyl ghrelin. Fatty acid modification of ghrelin is essential for ghrelin-induced growth hormone release from the pituitary and appetite stimulation. This acyl-modification of ghrelin is catalysed by ghrelin-O-acyl transferase recently identified. Despite the number of innovative advancements in this field of research, there are still many aspects of ghrelin function and biosynthesis process that remain to be clarified. Here, we review the current understanding of the structure, regulation and function of ghrelin; this review is intended... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635110 Wed, 25 Jan 2012 05:00:00 +0100 5635110 http://www.medworm.com/index.php?rid=5635109&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F2%2F115%3Frss%3D1 Nuclear factor-B (NF-B) is a master regulator of immunity and also involved in malignant transformation. It has been widely accepted that Lys-48 (K48)-linked polyubiquitination plays a critical role in NF-B signalling by targeting inhibitor of NF-B (IB), thereby leading to its degradation by the proteasome. Alternatively, studies on IL-1 and TNF signalling have revealed that proteins modified with K63-linked polyubiquitin chains do not undergo the proteasomal degradation, instead, function as the signalling platforms required for the activation of the IB kinase (IKK) complex. From the studies on lymphoid malignancies, human T cell leukaemia virus 1-derived protein, Tax, has been shown to activate the IKK complex, although the mechanism is largely unknown. Recently, Shibata et al. (Activati... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5635109 Wed, 25 Jan 2012 05:00:00 +0100 5635109 http://www.medworm.com/index.php?rid=5549431&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F109%3Frss%3D1 There is a little information about the effects of iron overload on cartilage metabolism. In the present study, we examined the effects of excess iron on the differentiation and mineralization of cultured chondrocytes, ATDC5 cells. We used ferric ammonium citrate (FAC) as a ferric ion donor and desferrioxamine (DFO) as a ferric ion chelator. Neither chemical affected the production of proteoglycan, a marker of an early stage of ATDC5 differentiation. In contrast, FAC inhibited the deposition of calcium, a late-stage event in chondrocyte differentiation, by ATDC5 cells in a dose-dependent manner, and DFO accelerated it. Energy dispersive X-ray spectroscopy/scanning electron microscope analysis revealed that the levels of iron and calcium in cells treated with FAC were increased and decrease... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549431 Mon, 26 Dec 2011 05:00:00 +0100 5549431 http://www.medworm.com/index.php?rid=5549430&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F99%3Frss%3D1 We previously reported that an isoform of microtubule-associated protein 4 (MAP4) is localized to the distal area of developing neurites, where microtubules are relatively scarce, raising the possibility that MAP4 interacts with another major cytoskeletal component, actin filaments. In the present study, we examined the in vitro interaction between MAP4 and actin filaments, using bacterially expressed MAP4 and its truncated fragments. Sedimentation assays revealed that MAP4 and its microtubule-binding domain fragments bind to actin filaments under physiological conditions. The apparent dissociation constant and the binding stoichiometry of the fragments to actin were about 0.1 µm and 1 : 3 (MAP4/actin), respectively. Molecular dissection studies revealed that the actin-binding site o... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549430 Mon, 26 Dec 2011 05:00:00 +0100 5549430 http://www.medworm.com/index.php?rid=5549429&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F89%3Frss%3D1 In this study, we identified and characterized ATX, a novel alternative splice variant of ATX, which has a four-amino acid deletion in the L2 linker region of ATXβ. ATX was found to be the second major isoform following ATXβ and fully active. ATXβ and ATX showed similar divalent cation sensitivity and cell motility-stimulating activity. ATXβ and ATX are present in wide range of organism from fish to mammals. Among them, only ATX was found in Gallus gallus and Xenopus laevis, suggesting the indispensable role of the isoform. ATX was expressed in various human tissues with different expression patterns from that of ATXβ. These results show that ATX is a second major ATX isoform sharing similar biochemical characters with the major isoform, ATXβ, and is a potenti... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549429 Mon, 26 Dec 2011 05:00:00 +0100 5549429 http://www.medworm.com/index.php?rid=5549428&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F75%3Frss%3D1 The Ars insulator is a boundary element identified in the upstream region of the arylsulfatase (HpArs) gene in the sea urchin, Hemicentrotus pulcherrimus, and possesses the ability to both block enhancer–promoter communications and protect transgenes from silent chromatin. To understand the molecular mechanism of the Ars insulator, we investigated the correlation between chromatin structure, DNA structure and insulator activity. Nuclease digestion of nuclei isolated from sea urchin embryos revealed the presence of a nuclease-hypersensitive site within the Ars insulator. Analysis of micrococcal nuclease-sensitive sites in the Ars insulator, reconstituted with nucleosomes, showed the exclusion of nucleosomes from the central AT-rich region. Furthermore, the central AT-rich region in na... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549428 Mon, 26 Dec 2011 05:00:00 +0100 5549428 http://www.medworm.com/index.php?rid=5549427&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F65%3Frss%3D1 In this study, we examined the effect of porphyran on nitric oxide (NO) production in mouse macrophage cell line RAW264.7 cells. Although no significant activity of porphyran to induce NO or tumour necrosis factor-α (TNF-α) production in RAW264.7 cells was observed at the concentration range tested (10–500 µg/ml), it was found for the first time that porphyran inhibited NO production and expression of inducible nitric oxide synthase (iNOS) in RAW264.7 cells stimulated with lipopolysaccharide (LPS). In the presence of 500 µg/ml porphyran, NO production and expression of iNOS in LPS-treated RAW264.7 cells were completely suppressed. On the other hand, porphyran showed only a marginal effect on the secretion of TNF-α from LPS-stimulated RAW264.7 cells. Elec... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549427 Mon, 26 Dec 2011 05:00:00 +0100 5549427 http://www.medworm.com/index.php?rid=5549426&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F57%3Frss%3D1 Mannan-binding lectin (MBL) was first discovered as a collectin in animal blood, and was shown to have such unique characteristics as a collage-like domain and a carbohydrate recognition domain. We recently identified human collectin kidney 1 (CL-K1, COLEC11) from a human kidney cDNA library. To quantitate the CL-K1 concentration in blood, we developed several polyclonal and monoclonal antibodies using recombinant human CL-K1 in CHO cells and the CL-K1 fragment in Escherichia coli. Using these antibodies, we established a sandwich enzyme-linked immunosorbent assay (ELISA) system. The concentration of CL-K1 in human plasma was 0.34 ± 0.13 µg/ml and that in MBL was 1.72 ± 1.51 µg/ml. Concentrations of MBL are often low due to its single nucleotide polymorphisms (SNP... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549426 Mon, 26 Dec 2011 05:00:00 +0100 5549426 http://www.medworm.com/index.php?rid=5549425&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F47%3Frss%3D1 In this study, we prepared two colony stimulating factor-1 receptor (CSF-1R) tyrosine kinase proteins: one highly phosphorylated by autophosphorylation and the other dephosphorylated by phosphatase treatment. These kinases were subjected to an activity-based assay to investigate the effect of their phosphorylation state on the potency of several kinase inhibitors. Dasatinib, sorafenib, PD173074 and staurosporine showed similar inhibition against different phosphorylation states of CSF-1R, but pazopanib, sunitinib, GW2580 and imatinib showed more potent inhibition against dephosphorylated CSF-1R. Binding analysis of the inhibitors to the two different phosphorylation forms of CSF-1R, using surface plasmon resonance spectrometry, revealed that staurosporine bound to both forms with similar a... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549425 Mon, 26 Dec 2011 05:00:00 +0100 5549425 http://www.medworm.com/index.php?rid=5549424&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F35%3Frss%3D1 In this study, we determined binding sites of BPA to PDI and characterized the binding site. First, we identified the BPA-binding domain with ab, b'a'c, a, b, b' and a'c fragment peptides of PDI by surface plasmon resonance spectroscopy. BPA interacted with ab, b'a 'c, a and b', suggesting that a and b' domains are important in their interaction. Second, ab, b'a'c, a,b,b',a', abb'a', abb', b'a', b' and a'c fragment peptides were used for their isomerase activity with RNase as a substrate. BPA could inhibit the activity of peptide fragments including b', suggesting that b' domain contributes to inhibition of catalytic activity of PDI by BPA. Next, we investigated the BPA-binding capacity of PDI by amino acid substitution. PDI lost the BPA-binding activity by the mutation of H258 and mutatio... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549424 Mon, 26 Dec 2011 05:00:00 +0100 5549424 http://www.medworm.com/index.php?rid=5549423&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F27%3Frss%3D1 This article proposes a new technique for the solubilization of poorly soluble drugs using lauroyl-L-glutamate, which is one of the amino acid detergents, with additional small additives. Lauroyl-L-glutamate was highly effective in solubilizing long-chain alkyl gallates, e.g. dodecyl gallate. Furthermore, lauroyl-L-glutamate and small additives, particularly arginine, acted to increase the solubility of alkyl gallates. The synergistic effect was not observed by sodium dodecyl sulphate with arginine. The solubilizing system can be applied to other drugs because of the low toxicity of both lauroyl-L-glutamate and arginine. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549423 Mon, 26 Dec 2011 05:00:00 +0100 5549423 http://www.medworm.com/index.php?rid=5549422&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F13%3Frss%3D1 Peptidases or proteinases are now classified into seven families based on the nature of the catalytic residues [MEROPS—the peptidase database (http://merops.sanger.ac.uk/)]. They are aspartic- (first described in 1993), cysteine- (1993), serine- (1993) metallo- (1993), threonine- (1997), glutamic- (2004) and asparagine-peptidase (2010). By using an S-PI (pepstatin Ac) as a probe, a new subfamily of serine peptidase, serine-carboxyl peptidase (sedolisin) was discovered in 2001. In addition, the sixth family of peptidase, glutamic peptidase (eqolisin) was also discovered in 2004. The former peptidase is widely distributed in nature from archea to mammals, including humans. One of these enzymes is related to a human fatal hereditable disease, Batten disease. In contrast, the distributio... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549422 Mon, 26 Dec 2011 05:00:00 +0100 5549422 http://www.medworm.com/index.php?rid=5549421&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F5%3Frss%3D1 RIG-I-like receptors, including RIG-I, MDA5 and LGP2, recognize cytoplasmic viral RNA. The RIG-I protein consists of N-terminal CARDs, central RNA helicase and C-terminal domains. RIG-I activation is regulated by ubiquitination. Three ubiquitin ligases target the RIG-I protein. TRIM25 and Riplet ubiquitin ligases are positive regulators of RIG-I and deliver the K63-linked polyubiquitin moiety to RIG-I CARDs and the C-terminal domain. RNF125, another ubiquitin ligase, is a negative regulator of RIG-I and mediates K48-linked polyubiquitination of RIG-I, leading to the degradation of the RIG-I protein by proteasomes. The K63-linked polyubiquitin chains of RIG-I are removed by a deubiquitin enzyme, CYLD. Thus, CYLD is a negative regulator of RIG-I. Furthermore, TRIM25 itself is regulated by ub... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549421 Mon, 26 Dec 2011 05:00:00 +0100 5549421 http://www.medworm.com/index.php?rid=5549420&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F151%2F1%2F1%3Frss%3D1 Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is synthesized as a membrane-anchored protein, known as proHB-EGF. ProHB-EGF is cleaved by metalloproteases through a process referred to as ‘ectodomain shedding’, resulting in the formation of soluble HB-EGF. Both proHB-EGF and soluble HB-EGF are biologically active; the former acts on neighbouring cells through juxtacrine signalling, whereas the latter can move to distant locations. Elevated HB-EGF expression has been observed in ovarian and some other cancers. CRM197, a diphtheria toxin (DT) mutant, binds directly to the epidermal growth factor (EGF)-like domain and represses the mitogenic activity of HB-EGF. Recently, monoclonal antibodies (mAbs) specific for human HB-EGF were generated by immunizing HB-EGF... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5549420 Mon, 26 Dec 2011 05:00:00 +0100 5549420 http://www.medworm.com/index.php?rid=5464877&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F687%3Frss%3D1 Altered expression of plasminogen activator inhibitor type-1 (PAI-1), a physiologic fibrinolysis inhibitor, is implicated in atherosclerosis. Cyclic adenosine monophosphate (cAMP) alters PAI-1 expression in several cells. Nevertheless, posttranscriptional regulation of PAI-1 has not been elucidated. To determine whether cAMP affects PAI-1 expression at posttranscriptional level, we determined promoter activity, mRNA levels, 3'-untranslated region (UTR) activity and protein levels of PAI-1 using HepG2 cells. cAMP decreased PAI-1 promoter activity at 24 h and mRNA expression at 4 h while it increased mRNA expression and accumulation of PAI-1 protein into media at 24 h. Human PAI-1 mRNA exists in two subspecies (3.2 and 2.2 kb), and cAMP increased baseline luciferase activity of 3'-UTR of the... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464877 Wed, 30 Nov 2011 05:00:00 +0100 5464877 http://www.medworm.com/index.php?rid=5464876&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F679%3Frss%3D1 Activation of NF-B by human T cell leukaemia virus type 1 Tax is thought to be crucial in T-cell transformation and the onset of adult T cell leukaemia. Tax activates NF-B through activation of the IB kinase (IKK) complex, similar to cytokine-induced NF-B activation, which involves active signalling complex formation using polyubiquitin chains as a platform. Although polyubiquitination of Tax was reported to be required for IKK activation, most studies have been performed using intact cells, in which secondary NF-B activation can be induced by various cytokines that are secreted due to Tax-mediated primary NF-B activation. Therefore, a cell-free assay system, in which IKK can be activated by adding highly purified recombinant Tax to cytosolic extract, was used to analyse Tax-induced IKK ac... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464876 Wed, 30 Nov 2011 05:00:00 +0100 5464876 http://www.medworm.com/index.php?rid=5464875&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F671%3Frss%3D1 Senescence marker protein-30 (SMP30) has been identified as the lactone-hydrolysing enzyme gluconolactonase (GNL), which is involved in vitamin C (l-ascorbic acid, AA) biosynthesis. We previously reported the development of SMP30/GNL knockout (KO) mice unable to synthesize AA in vivo. For more efficient study of the liver's AA uptake and as yet uncharacterized efflux system, we established an immortal hepatocyte line derived from a hybrid of SMP30/GNL KO mice and Immortomice. Immortomice express the thermolabile simian virus 40 (SV40) large T antigen tsA58. These SMP30/GNL KO immortal hepatocytes proliferate at the permissive temperature of 33°C but degrade rapidly at the non-permissive temperature of 39°C. Additionally, they are SMP30-/GNL-deficient, express SV40 large T antigen a... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464875 Wed, 30 Nov 2011 05:00:00 +0100 5464875 http://www.medworm.com/index.php?rid=5464874&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F659%3Frss%3D1 The mature form of l-Phe oxidase of Pseudomonas sp. P-501 (PAOpt) catalyzes the oxygenative decarboxylation of l-Phe and the oxidative deamination of l-Met, and is highly specific for l-Phe. The crystal structures of PAOpt individually complexed with l-Phe and l-Met and the properties of the active site mutants were investigated to clarify the structural basis of the substrate and reaction specificities of the enzyme. The benzene ring of l-Phe is packed in six hydrophobic amino acid side chains versus the two hydrophobic side chains of l-amino acid oxidase (LAO, pdb code: 2jb2); the distance between the substrate Cα atom and water is shorter in the PAOpt-l-Met complex than in the PAOpt-l-Phe complex; and the mutation of substrate carboxylate-binding residues (Arg143 and Tyr536) cause... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464874 Wed, 30 Nov 2011 05:00:00 +0100 5464874 http://www.medworm.com/index.php?rid=5464873&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F649%3Frss%3D1 In this study, we identified a novel MutT homolog (NDX-1) of Caenorhabditis elegans that hydrolyzes 8-oxo-dGDP to 8-oxo-dGMP. NDX-1 did not hydrolyze 8-oxo-dGTP, 2-hydroxy-dATP or 2-hydroxy-dADP. Expression of NDX-1 significantly reduced spontaneous A:T to C:G transversions and mitigated the sensitivity to a superoxide-generating agent, methyl viologen, in an E. coli mutT mutant. In C. elegans, RNAi of ndx-1 did not affect the lifespan of the worm. However, the sensitivity to methyl viologen and menadione bisulfite of the ndx-1-RNAi worms was enhanced compared with that of the control worms. These facts indicate that NDX-1 is involved in sanitization of 8-oxo-dGDP and plays a critical role in defense against oxidative stress in C. elegans. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464873 Wed, 30 Nov 2011 05:00:00 +0100 5464873 http://www.medworm.com/index.php?rid=5464872&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F635%3Frss%3D1 Fish genomes possess three type II interferon (IFN) genes, ifn1, ifn2 and ifn-related (ifnrel). The IFN-dependent STAT signalling pathway found in humans and mice had not been characterized in fish previously. To identify the antiviral functions and signalling pathways of the type II IFN system in fish, we purified the ifn1, ifn2 and ifnrel proteins of ginbuna crucian carp expressed in bacteria and found them to elicit high antiviral activities against crucian carp hematopoietic necrosis virus. We also cloned two distinct ifn receptor alpha chain (ifngr1) isoforms, 1 and 2, and stably expressed them in HeLa cells by transfecting the cells with ifngr1-1 or ifngr1-2 cDNA. When receptor transfectants were treated with the ligands in a one-ligand-one-receptor manner (ifn1 and ifngr1-2 or ifn2 ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464872 Wed, 30 Nov 2011 05:00:00 +0100 5464872 http://www.medworm.com/index.php?rid=5464871&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F627%3Frss%3D1 In this study, we have investigated the biochemical properties of recombinant DLP-1 wild-type and selected mutants, all expressed in Escherichia coli. The middle domain mutants G350D, R365S and PH (lacking the putative PH-like domain) severely impair the GTPase activity, but have no obvious effects on protein tetramerization and liposome-binding properties, suggesting these mutants probably affect protein intra-molecular interactions. Our study also suggested that proper domain–domain interactions are important for DLP-1 GTPase activity. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464871 Wed, 30 Nov 2011 05:00:00 +0100 5464871 http://www.medworm.com/index.php?rid=5464870&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F615%3Frss%3D1 Disruptants of genes encoding the ZnuABC high-affinity zinc incorporator and zosA encoding a P-type ATPase for zinc incorporation were identified to show low transformability. The low transformability of the znuB cells was rescued by excess zinc addition and epistatic analysis of the mutation revealed no effect on the expression of comK, which encodes a master regulator for late com operons. We further examined the expression of each late com operon in the znuA mutant and found that the znuA mutation specifically inhibited the expression of comF, but not the other late com operons. The addition of zinc also rescued the low transformability of the zosA cells. In zosA cells, transcription of comK was severely repressed. Using a strain carrying comK driven by a xylose-inducible promoter, we s... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464870 Wed, 30 Nov 2011 05:00:00 +0100 5464870 http://www.medworm.com/index.php?rid=5464869&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F607%3Frss%3D1 In this study, the crystal structure of Thermus thermophilus HICDH in a binary complex with a designed inhibitor, (2S,3S)-thiahomoisocitrate, has been determined at 2.6 Å resolution. The inhibitor observed as a decarboxylated product interacts through hydrogen bonding to Arg 118, Tyr 125 and Lys 171 in the active site. The induced fitting was also observed around the region consisting of residues 120–141, which shifted up to 2.8 Å towards the active site. In addition, it was found that the complex structure adopts a closed conformation in two domains. While the structure of apo-HICDH shows that a catalytic residue Tyr 125 and Arg 85 that engages in substrate recognition are flipped out of the active site, these residues turn towards the active site in the complex structur... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464869 Wed, 30 Nov 2011 05:00:00 +0100 5464869 http://www.medworm.com/index.php?rid=5464868&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F597%3Frss%3D1 Kunihiko Suzuki is a neurologist by training whose research accomplishments range widely from basic research in brain lipids, their metabolism to genetic disorders involving the nervous system. Among them are identification of the enzymatic defect, the pathogenetic mechanism, and animal models of Krabbe's globoid cell leukodystrophy, the chemical and molecular pathologies of many glycosphingolipidoses, discovery of the abnormal accumulation of very long chain fatty acids in adrenoleukodystrophy, and elucidation of the complex metabolic interrelationship among sphingolipids with extensive use of the gene targeting technology. This reflections and perspectives highlight his accomplishments briefly. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464868 Wed, 30 Nov 2011 05:00:00 +0100 5464868 http://www.medworm.com/index.php?rid=5464867&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F6%2F593%3Frss%3D1 Prostaglandin (PG) F2α is widely distributed in various organs and exhibits various biological functions, such as luteolysis, parturition, aqueous humor homeostasis, vasoconstriction, rennin secretion, pulmonary fibrosis and so on. The first enzyme reported to synthesize PGF2 was referred to as PGF synthase belonging to the aldo-keto reductase (AKR) 1C family, and later PGF2α synthases were isolated from protozoans and designated as members of the AKR5A family. In 2003, AKR1B5, which is highly expressed in bovine endometrium, was reported to have PGF2α synthase activity, and recently, the paper entitled ‘Prostaglandin F2α synthase activities of AKR 1B1, 1B3 and 1B7’ was reported by Kabututu et al. (J. Biochem.145, 161–168, 2009). Clones that had al... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5464867 Wed, 30 Nov 2011 05:00:00 +0100 5464867 http://www.medworm.com/index.php?rid=5374685&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F579%3Frss%3D1 l-Lactate dehydrogenase (l-LDH) of Lactobacillus casei (LCLDH) is a typical bacterial allosteric l-LDH that requires fructose 1,6-bisphosphate (FBP) for its enzyme activity. A mutant LCLDH was designed to introduce an inter-subunit salt bridge network at the Q-axis subunit interface, mimicking Lactobacillus pentosus non-allosteric l-LDH (LPLDH). The mutant LCLDH exhibited high catalytic activity with hyperbolic pyruvate saturation curves independently of FBP, and virtually the equivalent Km and Vm values at pH 5.0 to those of the fully activated wild-type enzyme with FBP, although the Km value was slightly improved with FBP or Mn2+ at pH 7.0. The mutant enzyme exhibited a markedly higher apparent denaturating temperature (T1/2) than the wild-type enzyme in the presence of FBP, but showed a... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374685 Fri, 28 Oct 2011 04:00:00 +0100 5374685 http://www.medworm.com/index.php?rid=5374684&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F569%3Frss%3D1 This study provided novel insights into the oligosaccharide binding mechanism and the catalytic residues of the enzymes belonging to family GH-23. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374684 Fri, 28 Oct 2011 04:00:00 +0100 5374684 http://www.medworm.com/index.php?rid=5374683&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F563%3Frss%3D1 Old yellow enzyme (OYE) is an NADPH oxidoreductase capable of reducing a variety of compounds. It contains flavin mononucleotide (FMN) as a prosthetic group. A ternary complex structure of OYE from Trypanosoma cruzi (TcOYE) with FMN and one of the substrates, p-hydroxybenzaldehyde, shows a striking movement around the active site upon binding of the substrate. From a structural comparison of other OYE complexed with 12-oxophytodienoate, we have constructed a complex structure with another substrate, prostaglandin H2 (PGH2), to provide a proposed stereoselective reaction mechanism for the reduction of PGH2 to prostaglandin F2α by TcOYE. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374683 Fri, 28 Oct 2011 04:00:00 +0100 5374683 http://www.medworm.com/index.php?rid=5374682&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F553%3Frss%3D1 NF-kappaB repressing factor (NRF) is a nuclear transcription factor that binds to a specific DNA sequence in NF-kappaB target promoters. Previous reports suggested that NRF interferes with the transcriptional activity of NF-kappaB binding sites through a direct interaction with NF-kappaB subunits. The aim of this study was to map specific NRF binding domains in the NF-kappaB proteins, p65 and p50. Our data demonstrate that NRF is able to interact with the p65 subunit and inhibit its transcription enhancing activity in reporter gene experiments. Using tandem affinity purifications (TAP), we show that NRF protein significantly binds to the endogenous p65, subunit but not to the p50 subunit. The selective binding activity of the NRF protein is consistently mediated by the N-terminal domain of... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374682 Fri, 28 Oct 2011 04:00:00 +0100 5374682 http://www.medworm.com/index.php?rid=5374681&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F545%3Frss%3D1 Sialic acid represents a critical sugar component located at the outermost position of glycoconjugates, playing important roles in extensive biological processes. To date, however, there have been only few probes which show affinity to α(2,3)-linked sialic acid-containing glycoconjugates. Agrocybe cylindracea galectin is known to have a relatively high affinity towards Neu5Acα(2,3)Galβ(1,4)Glc (3'-sialyl lactose), but it significantly recognizes various β-galactosides, such as Galβ(1,4)GlcNAcβ (LacNAc) and Galβ(1,3)GalNAcα (T-antigen). To eliminate this background specificity, we focused an acidic amino acid residue (Glu86), which interacts with the glucose unit of 3'-sialyl lactose and substituted it with all other amino acids. Carbohydrate-bindi... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374681 Fri, 28 Oct 2011 04:00:00 +0100 5374681 http://www.medworm.com/index.php?rid=5374680&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F535%3Frss%3D1 Crystallizing RNA has been an imperative and challenging task in the world of RNA research. Assistive methods such as chaperone-assisted RNA crystallography (CARC), employing monoclonal antibody fragments (Fabs) as crystallization chaperones have enabled us to obtain RNA crystal structures by forming crystal contacts and providing initial phasing information. Despite the early successes, the crystallization of large RNA–Fab complex remains a challenge in practice. The possible reason for this difficulty is that the Fab scaffold has not been optimized for crystallization in complex with RNA. Here, we have used the surface entropy reduction (SER) technique for the optimization of C209 P4–P6/Fab2 model system. Protruding lysine and glutamate residues were mutated to a set of alani... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374680 Fri, 28 Oct 2011 04:00:00 +0100 5374680 http://www.medworm.com/index.php?rid=5374679&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F525%3Frss%3D1 Genome analysis has indicated that plants, like animals, possess a variety of protease genes. However, bulk of putative proteases has not been characterized at the enzyme level. In this article, a novel enzyme that hydrolyses phenylalanyl-4-methylcoumaryl 7-amide (phenylalanyl-MCA) was purified from cotyledons of daikon radish by ammonium sulphate fractionation and successive chromatography with DEAE-cellulose, phenyl-Sepharose, Sephacryl S-200 and Mini-Q. The molecular mass of the enzyme was estimated to be 78 kDa by SDS–PAGE under reducing conditions and 74 kDa by gel filtration, indicating that the enzyme is a monomer. The deduced amino acid sequence from the cDNA nucleotide sequence indicated that the enzyme is an orthologue of Arabidopsis unidentified protein, acylpeptide hydrol... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374679 Fri, 28 Oct 2011 04:00:00 +0100 5374679 http://www.medworm.com/index.php?rid=5374678&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F515%3Frss%3D1 Anti-Lactobacillus johnsonii (LJ) antisera generated by immunization of rabbits with LJ reacted with glyceroglycolipids in LJ, i.e. dihexaosyl diacylglycerol (DH-DG), trihexaosyl DG (TH-DG) and tetrahexaosyl DG (TetH-DG), whose reactivities with antisera increased proportionally with longer carbohydrate chains of glycolipids. Structural analyses of glycolipids from LJ revealed that DH-DG was Galα1-2Glcα1-3'DG, and TH-DG and TetH-DG were novel derivatives of it with α-Gal at the non-reducing terminal, i.e. Galα1-6Galα1-2Glcα1-3'DG and Galα1-6Galα1-6Galα1-2Glcα1-3'DG, respectively. DH-DG was commonly present in several lactobacilli examined, but TetH-DG was restricted to LJ, L. intestinalis and L. reuteri, while the TH-DGs from L. c... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374678 Fri, 28 Oct 2011 04:00:00 +0100 5374678 http://www.medworm.com/index.php?rid=5374677&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F501%3Frss%3D1 The present study reports a new type of skin mucus lectin found in catfish Silurus asotus. The lectin exhibited calcium-dependent mannose-binding activity. When mannose eluate from chromatography with mannose-conjugated agarose was analysed by SDS–PAGE, the lectin appeared as a single 35-kDa band. Gel filtration showed that the lectin forms monomers and dimers. A 1216-bp cDNA sequence obtained by RACE–PCR from the skin encoded a 308 amino acid secretory protein with homology to mammalian and fish intelectins. RT–PCR demonstrated that the lectin gene was expressed in the gill, kidney and skin. Subsequent sequencing revealed the presence of an isoform in the gills. Antiserum detected the intelectin protein in club cells in the skin and gill, renal tubules and blood plasma. ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374677 Fri, 28 Oct 2011 04:00:00 +0100 5374677 http://www.medworm.com/index.php?rid=5374676&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F491%3Frss%3D1 Copper is an essential nutrient, but it is toxic in excess. Here, we cloned and characterized a His-rich low molecular weight dehydrin from Musa paradisiaca, MpDhn12. Analysis by circular dichroism (CD) spectra and a thermal stability assay showed that MpDhn12 is an intrinsically disordered protein, and immobilized-metal affinity chromatography (IMAC) analysis revealed that MpDhn12 can bind Cu2+ both in vitro and in vivo. Interestingly, MpDhn12 aggregated under excess Cu2+ conditions, and the aggregation was reversible and impaired by histidine modification with diethylpyrocarbonate (DEPC), while the disordered structure of another dehydrin ERD14 (as a control) was not changed. Furthermore, MpDhn12 could complement the copper-sensitive phenotype of yeast mutant sod1. These results together... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374676 Fri, 28 Oct 2011 04:00:00 +0100 5374676 http://www.medworm.com/index.php?rid=5374675&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F483%3Frss%3D1 Dr Tsuiki made three major contributions during his illustrious career as a biochemist. First, he developed the procedure for mucin isolation from bovine submaxillary glands. His work became the basis for mucin biochemistry. Second, he identified four distinct molecular species of mammalian sialidase. Subsequent studies based on his work led to the discovery that sialidase plays a unique role as an intracellular signalling factor involved in the regulation of a variety of cellular functions. Finally, he established the molecular basis for the diversity of mammalian protein phosphatases through protein purification and molecular cloning. His work prompted the functional studies of protein phosphatases. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374675 Fri, 28 Oct 2011 04:00:00 +0100 5374675 http://www.medworm.com/index.php?rid=5374674&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F477%3Frss%3D1 Lectins are proteins that agglutinate cells and exhibit an antibody like, sugar-binding specificity. Professor Toshiaki Osawa has discovered, purified and characterized many plant lectins that display diverse biological activities. Using lectins as biochemical tools, he developed methods to determine the biochemical structures of glycoprotein glycans that react with lectins; separated and characterized glycoproteins and cell populations; analysed the mechanisms by which lectins activate cells; and characterized several cytokines produced by immune cells stimulated by lectins. The studies on lectins, the field he took strong leadership, developed into an essential hub of the biology of multicellular organisms. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374674 Fri, 28 Oct 2011 04:00:00 +0100 5374674 http://www.medworm.com/index.php?rid=5374673&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F5%2F473%3Frss%3D1 Recent reports have indicated that some low-molecular-weight compounds mimic neurotrophic factors inducing neurite outgrowth and neuroprotection. Carnosic acid (CA) promotes neurite outgrowth through the activation of Nrf2 in PC12 cells. CA also protects neurons via the keap/Nrf2 transcriptional pathway from oxidative stress. Forskolin-induced neurite outgrowth is mediated by activation of the PKA signalling pathway and this PKA-mediated neurite outgrowth is achieved by the expression of nur77 in PC12 cells. In addition, forskolin at its low concentration is closely related to the cAMP-induced protective function against L-DOPA-induced cytotoxicity in PC12 cells. A HDAC inhibitor trichostatin A (TSA) increases neurite length via p53 acetylation in rat cultured cerebellar granule neurons an... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5374673 Fri, 28 Oct 2011 04:00:00 +0100 5374673 http://www.medworm.com/index.php?rid=5281161&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F461%3Frss%3D1 Cerium oxide (CeO2) is an important metal oxide used for industrial products. Many investigations about the cellular influence of CeO2 nanoparticles have been done, but results are contradictory. It has been reported that CeO2 nanoparticles have an anti-oxidative effect in cells, but it has also been reported that CeO2 nanoparticles induce oxidative stress. We investigated the potential influence on cells and the mechanisms induced by CeO2 nanoparticles in vitro. We prepared a stable CeO2 culture medium dispersion. Cellular responses in CeO2 medium-exposed cells were examined. Cellular uptake of CeO2 nanoparticles was observed. After 24-h exposure, a high concentration of CeO2 nanoparticles (~200 mg/ml) induced an increase in the intracellular level of reactive oxygen species (ROS); a low ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281161 Fri, 30 Sep 2011 04:00:00 +0100 5281161 http://www.medworm.com/index.php?rid=5281160&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F451%3Frss%3D1 Neural-restrictive silencer (NRS) has been well characterized in SCG10 and many other neuron-specific genes; it is, however, unknown whether the promoters of the SCLIP and RB3 genes (two other SCG10 family members) share basal transcriptional mechanisms with SCG10 or not. To explore how NRS-mediated neural-specific gene transcription has evolved, we determined the genomic and promoter structures of the SCLIP gene, and found that the gene retained an NRS-like element that functioned as a negative regulator in non-neuronal cells. However, unlike the NRS in the SCG10 gene, this NRSSCLIP was located downstream of the transcription start site, and showed a position-dependent repressing activity. Further gel-shift and NRS factor (NRSF) co-transfection experiments revealed that NRSSCLIP was bound... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281160 Fri, 30 Sep 2011 04:00:00 +0100 5281160 http://www.medworm.com/index.php?rid=5281159&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F439%3Frss%3D1 We previously isolated phage antibodies from a phage library displaying human single chain antibodies (scFvs) by screening with a mannotriose (Man3)-bearing lipid. Of four independent scFv genes originally characterized, 5A3 gene products were purified as fusion proteins such as a scFv-human IgG1 Fc form, but stable clones secreting 1A4 and 1G4 scFv-Fc proteins had never been established. Thus, bacterial expression systems were used to purify 1A4 and 1G4 scFv gene products as soluble forms. Purification of 1A4 and 1G4 scFv proteins from inclusion bodies was also carried out together with purification of 5A3 scFv protein in order to compare their Man3-binding abilities. The present studies demonstrated that 1A4 and 1G4 scFv proteins have a higher affinity for Man3 than 5A3 scFv protein, whi... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281159 Fri, 30 Sep 2011 04:00:00 +0100 5281159 http://www.medworm.com/index.php?rid=5281158&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F431%3Frss%3D1 Candida albicans is a commensal organism, but causes life-threatening infections in immunocompromised patients. Certain factors such as yeast-hyphae transition and hydrolytic enzymes are suggested as virulence attributes of C. albicans. Among them, 10 types of secreted aspartic protease (SAP) genes have received particular attention as a major virulence gene family. However, their full functional repertoire, including its biochemical properties, remains to be elucidated. Hence, we purified all Sap isozymes using Pichia pastoris and comprehensively determined and compared their biochemical properties. While optimum pH of Sap7 was 6.5 and that of Sap8 was 2.5, presence of other Sap isozymes functioning within a broad range of optimum pH could allow C. albicans to survive and cause infections... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281158 Fri, 30 Sep 2011 04:00:00 +0100 5281158 http://www.medworm.com/index.php?rid=5281157&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F423%3Frss%3D1 In conclusion, the cell-free RNA replication systems should become useful tools for the study of the viral RNA replication. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281157 Fri, 30 Sep 2011 04:00:00 +0100 5281157 http://www.medworm.com/index.php?rid=5281156&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F411%3Frss%3D1 In this study, we detected enhancement of autolysis of mGFP-fused calpain-7 by coexpression with CHMP1B and observed further activation by additional coexpression of IST1 in HEK293T cells. We found that CL7MIT interacted with the second α-helical region of CHMP1B but not with the canonical C-terminal region containing MIM1 in vitro. Co-immunoprecipitation assays demonstrated that the interaction between CL7MIT and CHMP1B and between CL7MIT and IST1 became stronger when IST1 or CHMP1B was additionally coexpressed, suggesting formation of ternary complex of calpain-7, IST1 and CHMP1B. Moreover, subcellular fractionation analyses revealed increase of calpain-7 in membrane/organelle fractions by concomitant overexpression of these ESCRT-III family member proteins. (Source: Journal of Bio... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281156 Fri, 30 Sep 2011 04:00:00 +0100 5281156 http://www.medworm.com/index.php?rid=5281155&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F403%3Frss%3D1 The small heat shock protein (sHsp), categorized into a class of molecular chaperones, binds and stabilizes denatured proteins for the purpose of preventing aggregation. The sHsps undergo transition between different oligomeric states to control their nature. We have been studying the function of sHsp of Sulfolobus tokodaii, StHsp14.0. StHsp14.0 exists as 24meric oligomer, and exhibits oligomer dissociation and molecular chaperone activity over 80°C. We constructed and characterized StHsp14.0 mutants with replacement of the C-terminal IKI to WKW, IKF, FKI and FKF. All mutant complexes dissociated into dimers at 50°C. Among them, StHsp14.0FKF is almost completely dissociated, probably to dimers. All mutants protected citrate synthase (CS) from thermal aggregation at 50°C. But, t... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281155 Fri, 30 Sep 2011 04:00:00 +0100 5281155 http://www.medworm.com/index.php?rid=5281154&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F395%3Frss%3D1 Asp187 and Gln190 were predicted as conserved and closely located at the Na+ binding site in a topology and homology model structure of Na+/proline symporter (PutP) of Escherichia coli. The replacement of Asp187 with Ala or Leu did not affect proline transport activity; whereas, change to Gln abolished the active transport. The binding affinity for Na+ or proline of these mutants was similar to that of wild-type (WT) PutP. This result indicates Asp187 to be responsible for active transport of proline without affecting the binding. Replacement of Gln190 with Ala, Asn, Asp, Leu and Glu had no effect on transport or binding, suggesting that it may not have a role in the transport. However, in the negative D187Q mutant, a second mutation, of Gln190 to Glu or Leu, restored 46 or 7% of the trans... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281154 Fri, 30 Sep 2011 04:00:00 +0100 5281154 http://www.medworm.com/index.php?rid=5281153&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F385%3Frss%3D1 Brain tissue contains multiple forms of Phospholipase A2 (PLA2) whose activities are involved in intracellular and intercellular signalling related to normal functions such as long-term potentiation, neurotransmitter release, cell growth and differentiation. Among them, we focused on regulatory mechanism of cPLA2α (Group IVA cytosolic PLA2) in brain tissue. In the present study, we report the identification of a cPLA2-activating protein (cPLAP) in the bovine brain. cPLAP activity appeared as two major peaks with molecular masses of 200 and 42 kDa in a Superose 12 gel filtration FPLC column. The 42-kDa form of cPLAP, designated cPLAP, was further purified using a Mono S FPLC column to near homogeneity and characterized to as a GTP-binding protein (G protein). Metabolic labelling and i... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281153 Fri, 30 Sep 2011 04:00:00 +0100 5281153 http://www.medworm.com/index.php?rid=5281152&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F375%3Frss%3D1 We isolated a putative desaturase gene from a marine alga, Pinguiochrysis pyriformis MBIC 10872, which is capable of accumulating eicosapentaenoic acid (C20:55,8,11,14,17). The gene possessed an open reading frame of 1,314 bp encoding a putative 437 amino acid residues showing high sequence identity (37–48%) with fungal and nematode 12-fatty acid desaturases. Yeast cells transformed with the gene converted endogenous oleic acid (C18:19) to linoleic acid (C18:29,12). However, no double bonds were introduced into other endogenous fatty acids or exogenously added fatty acids. Flag-tagged enzyme was recovered in the micosome fraction when expressed in yeast cells. To express the gene in thraustochytrids, a construct driven by the thraustochytrid-derived ubiquitin promoter was used. Inter... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281152 Fri, 30 Sep 2011 04:00:00 +0100 5281152 http://www.medworm.com/index.php?rid=5281151&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F371%3Frss%3D1 We tested the capsid targeted viral inactivation method as an anti-HBV strategy. HepG2 cells were cotransfected with HBV expression plasmid and the plasmid encoding fusion protein of either Core-A3C or Core-humanized renilla GFP (hrGFP). Core-A3C had substantial effect on HBV DNA levels. In the HepG2 cells expressing Core-A3C, the number of G-to-A mutations increased dramatically, whereas other nucleotide substitutions were rare. In addition, Core-A3C substantially inhibited HBV production intracellularly and in culture supernatant. These results suggest that Core-A3C may be a candidate as a novel antiviral agent against human HBV infection. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281151 Fri, 30 Sep 2011 04:00:00 +0100 5281151 http://www.medworm.com/index.php?rid=5281150&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F357%3Frss%3D1 G protein-mediated signal transduction can transduce signals from a large variety of extracellular stimuli into cells and is the most widely used mechanism for cell communication at the membrane. The RhoGTPase family has been well established as key regulators of cell growth, differentiation and cell shape changes. Among G protein-mediated signal transduction, G12/13-mediated signalling is one mechanism to regulate RhoGTPase activity in response to extracellular stimuli. The alpha subunits of G12 or G13 have been shown to interact with members of the RH domain containing guanine nucleotide exchange factors for Rho (RH–RhoGEF) family of proteins to directly connect G protein-mediated signalling and RhoGTPase signalling. The G12/13–RH–RhoGEF signalling mechanism is well con... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281150 Fri, 30 Sep 2011 04:00:00 +0100 5281150 http://www.medworm.com/index.php?rid=5281149&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F345%3Frss%3D1 Oxidation of the catalytic cysteine of protein–tyrosine phosphatases (PTP), which leads to their reversible inactivation, has emerged as an important regulatory mechanism linking cellular tyrosine phosphorylation and signalling by reactive-oxygen or -nitrogen species (ROS, RNS). This review focuses on recent findings about the involved pathways, enzymes and biochemical mechanisms. Both the general cellular redox state and extracellular ligand-stimulated ROS production can cause PTP oxidation. Members of the PTP family differ in their intrinsic susceptibility to oxidation, and different types of oxidative modification of the PTP catalytic cysteine can occur. The role of PTP oxidation for physiological signalling processes as well as in different pathologies is described on the basis o... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281149 Fri, 30 Sep 2011 04:00:00 +0100 5281149 http://www.medworm.com/index.php?rid=5281148&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F4%2F341%3Frss%3D1 Riboflavin or vitamin B2 is one of the constituents of energy drinks. Although this compound is known to be absorbed in the intestine and that it circulates throughout the body and is excreted in urine, the transporter(s) responsible for the process was only recently identified. Yamamoto et al. identified this transporter through functional expression of rat orthologues of a putative bacterial riboflavin transporter. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5281148 Fri, 30 Sep 2011 04:00:00 +0100 5281148 http://www.medworm.com/index.php?rid=5168662&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F327%3Frss%3D1 Alkylation is a type of stress that is fatal to cells. However, cells have various responses to alkylation. Alkyltransferase-like (ATL) protein is a novel protein involved in the repair of alkylated DNA; however, its repair mechanism at the molecular level is unclear. DNA microarray analysis revealed that the upregulation of 71 genes because of treatment with an alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine was related to the presence of TTHA1564, the ATL protein from Thermus thermophilus HB8. Affinity chromatography showed a direct interaction of purified TTHA1564 with purified RNA polymerase holoenzyme. The amino acid sequence of TTHA1564 is homologous to that of the C-terminal domain of Ada protein, which acts as a transcriptional activator. These results suggest that TTHA1564 m... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168662 Thu, 25 Aug 2011 23:00:00 +0100 5168662 http://www.medworm.com/index.php?rid=5168661&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F319%3Frss%3D1 In this study, we developed a phosphatase assay of PPM1D using phosphatase motif-specific antibody. PPM1D is a member of PPM1 type Ser/Thr phosphatase and known to dephosphorylate Ser(P)-Gln sequence. The gene amplification and overexpression of PPM1D were reported in many human cancers. We generated the monoclonal antibody specific for the Ser(P)-Gln sequence, named 3G9-H11. The specificity of this method using ELISA enables the convenient measurement of the dephosphorylation level of only PPM1D target residues of substrate peptides with multiple phosphorylated sites in the presence of multiple phosphatases. In addition, the antibody was applicable to immunoblotting assay for PPM1D function analysis. These results suggested that this method should be very useful for the PPM1D phosphatase ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168661 Thu, 25 Aug 2011 23:00:00 +0100 5168661 http://www.medworm.com/index.php?rid=5168660&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F311%3Frss%3D1 Inflammation is often accompanied by hypoxia. However, crosstalk between signalling pathways activated by inflammation and signalling events that control adaptive response to hypoxia is not fully understood. Here we show that exposure to tumour necrosis factor-α (TNF-α) activates expression of the inhibitory PAS domain protein (IPAS) to suppress the hypoxic response caused by hypoxia-inducible factor (HIF)-1 and HIF-2 in rat pheochromocytoma PC12 cells but not in human hepatoma Hep3B cells. This induction of IPAS was dependent on the nuclear factor-B (NF-B) pathway and attenuated hypoxic induction of HIF-1 target genes such as tyrosine hydroxylase (TH) and vascular endothelial growth factor (VEGF). HIF-dependent reporter activity in hypoxia was also decreased following TNF-&alp... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168660 Thu, 25 Aug 2011 23:00:00 +0100 5168660 http://www.medworm.com/index.php?rid=5168659&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F303%3Frss%3D1 We examined the cellular content of glucosylceramide (GlcCer), the simplest of the GSLs, in a TPA-treated leukaemia cell line, U937. Following TPA treatment, we observed a 3.5-fold increase in GlcCer levels that was caused by enhanced activity of ceramide glucosyltransferase (GlcT-1), which catalyses ceramide glycosylation. Furthermore, in TPA-treated cell GlcT-1 amounts were increased at both the mRNA and protein levels. We also found decreased activity of lactosylceramide synthase in TPA-treated cells, which could also contribute to the increase in cellular GlcCer content. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168659 Thu, 25 Aug 2011 23:00:00 +0100 5168659 http://www.medworm.com/index.php?rid=5168658&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F295%3Frss%3D1 The genome sequence of an extremely thermophilic bacterium, Thermus thermophilus HB8, revealed that TTHA0350 is a tandem-type universal stress protein (Usp) consisting of two Usp domains. Usp proteins, which are characterized by a conserved domain consisting of 130–160 amino acids, are inducibly expressed under a large number of stress conditions. The N-terminal domain of TTHA0350 contains a motif similar to the consensus ATP-binding one (G-2 x-G-9x-G-(S/T)), but the C-terminal one seems to lack the consensus motif. In order to determine its structural properties, we determined the crystal structures of TTHA0350 in the unliganded form and TTHA0350•2ATP at 2.50 and 1.70 Å resolution, respectively. This is the first structure determination of a Usp family protein in both unl... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168658 Thu, 25 Aug 2011 23:00:00 +0100 5168658 http://www.medworm.com/index.php?rid=5168657&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F289%3Frss%3D1 We have developed a screening system for artificial small RNAs (sRNAs) that inhibit the growth of Escherichia coli. In this system, we used a plasmid library to express artificial sRNAs (approximately 200 bases long) containing 60 bases of random nucleotide sequence. The induced expression of the known rydB sRNA in the system reduced the amount of its possible target mRNA, rpoS, supporting the reliability of the method. To isolate clones of sRNAs that inhibited the growth of E. coli, we used two successive screening steps: (i) colony size selection on plates and (ii) monitoring E. coli growth in a 96-well plate format. As a result, 83 artificial sRNAs were identified that showed a range of inhibitory effects on bacterial growth. We also introduced nucleotide replacements into one of the hi... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168657 Thu, 25 Aug 2011 23:00:00 +0100 5168657 http://www.medworm.com/index.php?rid=5168656&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F279%3Frss%3D1 Lipocalins form a widespread class of proteins involved in the transport of weakly soluble vitamins, hormones or hydrophobic molecules. β-lactoglobulin (BLG-col), a major lipocalin present in whey was purified and characterized from buffalo colostrum. The molecular weight of BLG-col as determined by Liquid chromatography –electrospray ionization mass spectrometry (LC-ESI-MS) was 18.257 kDa and the peptide mass fingerprint of the purified protein revealed 67% sequence homology to buffalo milk β-lg. The N-terminal-IIVTQ and LC–ESI-collision-induced dissociation–Electron transfer dissociation mass spectrometry/mass spectrometry analyses of doubly (m/z 1156+2) and triply (m/z 546+3) charged ion pairs corresponding to VYVEELKPTPEGDLEILLQK (41–60) and TPEVDDEALE... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168656 Thu, 25 Aug 2011 23:00:00 +0100 5168656 http://www.medworm.com/index.php?rid=5168655&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F271%3Frss%3D1 In this study, a loss of this additional binding affinity appeared to cause the monocyte C5aR to activate an alternative signalling pathway. The p38 mitogen activated-protein kinase (MAPK) pathway was linked to cell migration rather than a classical extracellular-regulated kinase 1/2 pathway commonly used by C5a. C5aR internalization was not involved in the alternative chemotactic pathway. We propose a model of activation involving a C5aR co-molecule that interferes with the C5aR–Gi protein interaction upon binding to the I134–H145 in neutrophils; however, a free I134–H145 from the C5aR co-molecule can guide the alternative activation of the chemotactic p38MAPK pathway in monocytes/macrophages. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168655 Thu, 25 Aug 2011 23:00:00 +0100 5168655 http://www.medworm.com/index.php?rid=5168654&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F267%3Frss%3D1 In this study, we proposed that a trace amount of caldesmon (TACD) could highly, efficiently, interact with myosin by producing a ‘domino-like cascade’ and characterized that TACD (lowest caldesmon/myosin molar ratio: 1/10,000) significantly increased precipitations and intrinsic tryptophan fluorescence intensity of myosin in both phosphorylated and unphosphorylated states compared to the base controls (P < 0.01). Actin-blocked TACD–myosin interaction, suggesting that it functioned as a negative regulator. Since CaD is not an enzyme, the in vivo significance of the highly efficient TACD–myosin interaction needs further investigation. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168654 Thu, 25 Aug 2011 23:00:00 +0100 5168654 http://www.medworm.com/index.php?rid=5168653&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F257%3Frss%3D1 Hundreds of volatile organic compounds (VOCs) are emitted from the human body, and the components of VOCs usually reflect the metabolic condition of an individual. Therefore, contracting an infectious or metabolic disease often results in a change in body odour. Recent progresses in analytical techniques allow rapid analyses of VOCs derived from breath, blood, skin and urine. Disease-specific VOCs can be used as diagnostic olfactory biomarkers of infectious diseases, metabolic diseases, genetic disorders and other kinds of diseases. Elucidation of pathophysiological mechanisms underlying production of disease-specific VOCs may provide novel insights into therapeutic approaches for treatments for various diseases. This review summarizes the current knowledge on chemical and clinical aspects... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168653 Thu, 25 Aug 2011 23:00:00 +0100 5168653 http://www.medworm.com/index.php?rid=5168652&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F233%3Frss%3D1 Phospholipase A2 (PLA2) catalyses the hydrolysis of the sn-2 position of glycerophospholipids to yield fatty acids and lysophospholipids. So far, more than 30 enzymes that possess PLA2 or related activity have been identified in mammals. About one third of these enzymes belong to the secreted PLA2 (sPLA2) family, which comprises low molecular weight, Ca2+ requiring, secreted enzymes with a His/Asp catalytic dyad. Individual sPLA2s display distinct localizations and enzymatic properties, suggesting their specialized biological roles. However, in contrast to intracellular PLA2s, whose roles in signal transduction and membrane homoeostasis have been well documented, the biological roles of sPLA2s in vivo have remained obscure until recently. Over the past decade, information fuelled by studie... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168652 Thu, 25 Aug 2011 23:00:00 +0100 5168652 http://www.medworm.com/index.php?rid=5168651&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F223%3Frss%3D1 Lysophosphatidic acid (LPA) is a bioactive lipid mediator with diverse physiological and pathological actions on many types of cells. Originally, LPA was thought to elicit its biological functions through three subtypes of endothelial differentiation gene (Edg) family G protein-coupled receptors (LPA1, LPA2 and LPA3) until our group identified a fourth subtype, LPA4. The discovery of this receptor, which is structurally distinct from the Edg family LPA receptors, led to the identification of two additional LPA receptors, LPA5 and LPA6, homologous to LPA4. These ‘non-Edg family’ LPA receptors now provide a new framework for understanding the diverse functions of LPA, including vascular development, platelet activation and hair growth. In this review, we summarize the identificat... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168651 Thu, 25 Aug 2011 23:00:00 +0100 5168651 http://www.medworm.com/index.php?rid=5168650&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F3%2F219%3Frss%3D1 CCN family 2/connective tissue growth factor (CCN2/CTGF) is a secreted protein that regulates diverse cellular functions. In addition to being a growth factor to transmit mitogen-activated protein kinase (MAPK) signalling into cells, through largely unknown mechanism, CCN2 antagonizes bone morphogenetic proteins (BMPs) by direct interaction. CCN2 and BMPs co-localize in cartilage, and both of them promote proliferation and differentiation of chondrocytes in vivo and in vitro. However, it was unclear whether these growth factors act cooperatively, or mutually inhibitory in chondrocyte biology. In addition, an information whether the heterooligomer of CCN2 and BMPs has any physiological roles in skeletogenesis was completely missing. Takigawa and his colleagues have recently reported that CC... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5168650 Thu, 25 Aug 2011 23:00:00 +0100 5168650 http://www.medworm.com/index.php?rid=5076137&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F209%3Frss%3D1 Nerve growth factor (NGF) is a neurotrophic factor that plays an important role in neuronal cell development and survival. Carnosic acid (CA), a hydrophobic constituent of the herb rosemary, induces NGF production in human T98G glioblastoma cells, but the mechanism through which it works remains unknown. In the present study, we found a redox-sensitive transcription factor, Nrf2, which coordinates the expression of cytoprotective phase 2 genes, also participates in CA-inducible NGF expression. In T98G cells, CA caused NGF gene induction in a dose- and time-dependent manner without altering NGF mRNA stability. Simultaneously, CA increased Nrf2 nuclear accumulation and activated expression of prototypical Nrf2 target genes such as haem oxygenase 1 (HO-1) and thioredoxin reductase 1 (TXNRD1).... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076137 Thu, 28 Jul 2011 23:00:00 +0100 5076137 http://www.medworm.com/index.php?rid=5076136&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F199%3Frss%3D1 The mammalian Hippo pathway is composed of mammalian Ste20-like (MST) kinases and large tumour suppressor (LATS) kinases. Upon the activation of the pathway, MST kinases phosphorylate and activate LATS kinases, which in turn phosphorylate transcriptional co-activators, yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ), recruit them to the cytosol from the nucleus and turn off cell cycle-promoting and anti-apoptotic gene transcriptions. Thus, the pathway restricts cell overgrowth and prevents tumourigenesis. Although a high cell density and stress signallings are known to activate the pathway, no specific stimulators are so far reported. As the dysfunction of the pathway is frequent in human cancers and correlates with poor prognosis, it is important... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076136 Thu, 28 Jul 2011 23:00:00 +0100 5076136 http://www.medworm.com/index.php?rid=5076135&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F189%3Frss%3D1 Angiogenesis, the process of new blood vessels formation, is a critical step for wound healing, tumour growth and metastasis, diabetic retinopathy, psoriasis, etc. The present study was designed to investigate whether c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) is critical for regulating basic fibroblastic growth factor (bFGF)-induced angiogenesis in human umbilical vein endothelial cells (HUVECs). Our results showed that bFGF-induced HUVECs proliferation, migration and tube formation with a concentration-dependent manner. Further results showed that bFGF induced the phosphorylation of JNK/SAPK at 15 min. Both JNK/SAPK inhibitor SP600125 and JNK/SAPK peptide inhibitor 420116 could inhibit bFGF-induced HUVECs proliferation, migration and tube formation, so did JNK/SAP... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076135 Thu, 28 Jul 2011 23:00:00 +0100 5076135 http://www.medworm.com/index.php?rid=5076134&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F183%3Frss%3D1 In this study, we examined the mutational effects of Tyr219 on enzyme activity. Five Tyr219 variants, Y219F (Tyr219 is replaced with Phe), Y219D, Y219A, Y219C and Y219S, were constructed by site-directed mutagenesis. In the hydrolysis of (7-methoxycoumarin-4-yl)acetyl-l-Pro-l-Leu-Gly-l-Leu-[N3-(2,4-dinitrophenyl)-l-2,3-diaminopropionyl]-l-Ala-l-Arg-NH2, all five variants retained the activity, indicating that Tyr219 is not the ionizable group responsible for pKe2. Unexpectedly, all five variants exhibited narrower pH-dependence than the wild-type MMP-7, with the pKe1 and pKe2 values in the range of 5.2–5.4 and 8.6–9.4, respectively. Such pH-dependence shifts were not observed in other active-site tyrosyl-residue variants, Y193F and Y216F. These results suggest that Tyr219 is no... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076134 Thu, 28 Jul 2011 23:00:00 +0100 5076134 http://www.medworm.com/index.php?rid=5076133&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F173%3Frss%3D1 The nicotinamide adenine dinucleotide (NADH)/nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and the xanthine oxidase (XOD) systems generate reactive oxygen species (ROS). In the present study, to characterize the difference between the two systems, the kinetics of ROS generated by both the NADH oxidase and XOD systems were analysed by an electron spin resonance (ESR) spin trapping method using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), 5-(diethoxyphosphoryl)-5-methyl-pyrroline N-oxide (DEPMPO) and 5-(2,2-dimethyl-1,3-propoxy cyclophosphoryl)-5-methyl-1-pyrroline N-oxide (CYPMPO). As a result, two major differences in ROS kinetics were found between the two systems: (i) the kinetics of •OH and (ii) the kinetics of hydrogen peroxide. In the NADH oxidase system, the interactio... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076133 Thu, 28 Jul 2011 23:00:00 +0100 5076133 http://www.medworm.com/index.php?rid=5076132&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F165%3Frss%3D1 Alkyl gallates are anticipated for their use as anti-bacterial and anti-viral agents. Although their pharmacological activities depend on their alkyl chain length, no mechanism has yet been clarified. As described herein, we investigated the membrane binding properties of a series of alkyl gallates using fluorescence measurement to elucidate their different pharmacological activities. Membrane binding of the alkyl gallates increased concomitantly with increasing alkyl chain length, except for cetyl gallate and stearyl gallate. Dynamic light scattering revealed that alkyl gallates with a long alkyl chain are prone to self-association in the solution. Membrane binding abilities of the alkyl gallates are correlated with anti-bacterial and anti-virus activities, as described in previous report... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076132 Thu, 28 Jul 2011 23:00:00 +0100 5076132 http://www.medworm.com/index.php?rid=5076131&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F157%3Frss%3D1 The mature pro forms of the cardiac natriuretic peptides, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), are proteolytically processed to their active hormone forms (28 and 32 residues, respectively) and N-terminal (NT)-pro fragments (68 and 76 residues, respectively). Far-ultraviolet circular dichroism (UV CD), 1D and 2D-homonuclear nuclear magnetic resonance (NMR), size exclusion-high performance liquid chromatography (SE-HPLC) and analytical ultracentrifuge sedimentation equilibrium (AUCSE) data are obtained for NT-proANP. CD data showed a large negative molar ellipticity for NT-proANP of –14,800° cm2/dmol at 199–200 nm. The intensity of the 1D-1H NMR spectra in the amide region for NT-proANP was very low and confined to ~8–8.6 ppm. Furthermo... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076131 Thu, 28 Jul 2011 23:00:00 +0100 5076131 http://www.medworm.com/index.php?rid=5076130&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F151%3Frss%3D1 As a member of receptor tyrosine kinase (RTK) family, insulin-like growth factor-1 (IGF1) receptor (IGF1R) activates several downstream pathways to transmit proliferative signals from extracellular stimulation. AKT as a major effector plays a pivotal role in integrating various survival signalling cascades. Our data here show that hyperactive AKT leads to the decrease of IGF1R at the transcriptional level, which could be partly restored by phosphatidylinositol-3 kinase (PI3K) inhibitors including wortmannin and LY294002. Moreover, the decrease of IGF1R impairs the sensitivity of IRS1 to the stimulation by IGF1. mTOR as a main downstream target of AKT is not involved in the AKT-mediated down-regulation of IGF1R. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076130 Thu, 28 Jul 2011 23:00:00 +0100 5076130 http://www.medworm.com/index.php?rid=5076129&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F143%3Frss%3D1 Pathogen recognition is the first and crucial step in innate immunity. Molecular families involved in the recognition of pathogens and activation of the innate immune responses in immunoreactive cells include the Toll-like receptor family in mammals and the peptidoglycan recognition protein (PGRP) family in Drosophila, which sense microorganisms in an extracellular or luminal compartment. Other emerging families are the intracellular recognition molecules for bacteria, such as nucleotide binding and oligomerization domain-like receptors in mammals and PGRP–LE in Drosophila, several of which have been shown to detect structures of bacterial peptidoglycan in the host cell cytosol. Exciting advances in recent studies on autophagy indicate that macroautophagy (referred to here as autopha... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076129 Thu, 28 Jul 2011 23:00:00 +0100 5076129 http://www.medworm.com/index.php?rid=5076128&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F133%3Frss%3D1 The nuclear Dbf2-realted (NDR) family members are highly conserved serine/threonine protein kinases that function in concert with the Hippo signalling pathway to play crucial roles in regulation of cell proliferation and survival in non-neuronal cells. Recent studies employing a range of animal models have implicated NDR kinases as regulators of multiple aspects of development in post-mitotic neurons including progenitor proliferation, fate specification and circuit formation, all of which are crucial for neuronal functions. This review summarizes the recent advances in our understanding of the neuronal functions of NDR kinases and discusses their association with neuronal diseases. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076128 Thu, 28 Jul 2011 23:00:00 +0100 5076128 http://www.medworm.com/index.php?rid=5076127&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F127%3Frss%3D1 We have recently identified C-type lectin-like receptor 2 (CLEC-2) as a receptor for the platelet activating snake venom rhodocytin. CLEC-2 elicits powerful platelet activation signals in conjunction with single YxxL motif in its cytoplasmic tail, Src, Syk kinases, and phospholipase C2. An endogenous ligand of CLEC-2 has been identified as podoplanin, which is a membrane protein of tumour cells and facilitates tumour metastasis by inducing platelet activation. Studies of CLEC-2-deficient mice have revealed several physiological roles of CLEC-2. Podoplanin is also expressed in lymphatic endothelial cells. In the developmental stages, when the primary lymph sac is derived from the cardinal vein, podoplanin activates platelets in lymphatic endothelial cells, which facilitates blood/lymphatic ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076127 Thu, 28 Jul 2011 23:00:00 +0100 5076127 http://www.medworm.com/index.php?rid=5076126&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F2%2F123%3Frss%3D1 Matriptase is a type II transmembrane serine protease expressed abundantly in the epithelial cells and keratinocyte. It plays a key role in the establishment and maintenance of epithelial integrity. Matriptase is considered to be at the most upstream in cellular protease cascade. Activation of its zymogen is the most critical step in regulation of downstream proteases activities and physiological functions. It has recently found that the exposure of matriptase-expressing epithelial cells and its homogenate to mildly acidic pH induces the rapid activation of matriptase zymogen. On the other hand, high ionic strength prevents this activation. The activation of the zymogen is thought to be triggered by the acidification and the lowering of ionic strength in cell-surface microenvironments. (So... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=5076126 Thu, 28 Jul 2011 23:00:00 +0100 5076126 http://www.medworm.com/index.php?rid=4991367&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F121%3Frss%3D1 (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991367 Tue, 28 Jun 2011 23:00:00 +0100 4991367 http://www.medworm.com/index.php?rid=4991366&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F113%3Frss%3D1 We examined how electrostatic shielding affects the formation of two-dimensional (2D) crystals of bacteriorhodopsin (bR) in reconstituted dimyristoylphosphatidylcholine (DMPC) membranes by varying the sodium chloride (NaCl) concentration. The 2D crystalline array of bR formed in the gel phase of DMPC membranes was characterized by a symmetric bipolar pattern in visible circular dichroic spectra collected around 560 nm. The amplitude of the bipolar pattern was systematically enhanced by increasing the NaCl concentration. A strong correlation between the amplitude of the bipolar pattern and the Debye constant of small ions indicated that a weakening of electrostatic repulsion by the shielding effect of small ions enhances the order of 2D bR crystals in the gel phase of DMPC membranes. Consid... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991366 Tue, 28 Jun 2011 23:00:00 +0100 4991366 http://www.medworm.com/index.php?rid=4991365&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F103%3Frss%3D1 The Saccharomyces cerevisiae Yvh1, a dual-specificity protein phosphatase involved in glycogen accumulation and sporulation, is required for normal vegetative growth. To further elucidate the role of Yvh1, we generated dominant mutants suppressing the slow growth caused by YVH1 disruption. One of the mutant alleles, designated as SVH1-1 (suppressor of yvh1 deletion), was identical to MRT4 (mRNA turnover) that contained a single-base substitution causing an amino acid change from Gly68 to Asp. Mrt4(G68D) restored the deficiencies in growth and rRNA biogenesis that occurs in absence of Yvh1. Here, we report that the interaction between Mrt4 and Yvh1 is also essential for normal glycogen accumulation and mRNA decay as well as the induction of sporulation genes IME2, SPO13 and HOP1. The Mrt4(G... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991365 Tue, 28 Jun 2011 23:00:00 +0100 4991365 http://www.medworm.com/index.php?rid=4991364&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F95%3Frss%3D1 In this study, the dynamics of CSH, GSH and their disulphides in astrocyte culture medium were investigated by following the time-course of concentration changes and by computer simulation and curve fitting to experimental data using a mathematical model. The model consists of seven reactions and three transports, which are grouped into four categories: autoxidation of thiols into disulphides, thiol–disulphide exchange and reactions of thiols with medium components, as well as the cellular influx and efflux of thiols and disulphides. The obtained results are interpreted that cystine (CSSC) after entering astrocyte is reduced to CSH, most of which is released to medium and autoxidized to CSSC. The efflux of GSH was estimated to be considerably slower than that of CSH, and most of the ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991364 Tue, 28 Jun 2011 23:00:00 +0100 4991364 http://www.medworm.com/index.php?rid=4991363&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F83%3Frss%3D1 Pharbin, a 5-phosphatase that induces arborization, is one of the phosphoinositide 5-phosphatases that is highly mutated in patients with Joubert syndrome. Pharbin can hydrolyse PI(4,5)P2 and PI(3,4,5)P3 and has the same substrate specificity as SHIP2 and SKIP, which negatively regulate PI3K signalling. Here, we investigated the role of pharbin in IGF-1/PI3K signalling. Ectopic expression of pharbin markedly suppressed the IGF-1-induced activation of Akt without affecting p42/44 MAP kinase phosphorylation. In contrast, pharbin silencing by RNA interference increased the IGF-1-induced phosphorylation of Akt, suggesting that pharbin negatively regulates PI3K/Akt signalling. Pharbin expression also inhibited the phosphorylation of p70 S6 kinase and 4E-BP1 as well as the subsequent protein syn... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991363 Tue, 28 Jun 2011 23:00:00 +0100 4991363 http://www.medworm.com/index.php?rid=4991362&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F73%3Frss%3D1 In this study, we conducted a genome-scale experiment to assess the overexpression and the solubility of human full-length cDNA in an in vivo Escherichia coli expression system and a wheat germ cell-free expression system. We evaluated the influences of sequence and structural features on protein expression/solubility in each system and estimated a minimal set of features associated with them. A comparison of the feature sets related to protein expression/solubility in the in vivo Escherichia coli expression system revealed that the structural information was strongly associated with protein expression, rather than protein solubility. Moreover, a significant difference was found in the number of features associated with protein solubility in the two expression systems. (Source: Journal of ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991362 Tue, 28 Jun 2011 23:00:00 +0100 4991362 http://www.medworm.com/index.php?rid=4991361&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F61%3Frss%3D1 Endochondral ossification is a complex process involving the formation of cartilage and the subsequent replacement by mineralized bone. Although the proliferation and differentiation of chondrocytes are strictly regulated, the molecular mechanisms involved are not completely understood. Here, we show that a divergent-type homeobox gene, hematopoietically expressed homeobox gene (HEX), is expressed in mouse chondrogenic cell line ATDC5. The expression of Hex protein drastically increased during differentiation. The chondrogenic differentiation-enhanced expression of Hex protein was also observed in chondrocytes in the tibia of embryonic day 15.5 (E15.5) mouse embryos. The localization of Hex protein in the chondrocytes of the tibia changed in association with maturation; namely, there was H... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991361 Tue, 28 Jun 2011 23:00:00 +0100 4991361 http://www.medworm.com/index.php?rid=4991360&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F49%3Frss%3D1 Eukaryotic translation termination is triggered by peptide release factors eRF1 and eRF3. eRF1 recognizes the stop codon and promotes nascent peptide chain release, while eRF3 facilitates this peptide release in a GTP-dependent manner. In addition to its role in termination, eRF3 is involved in normal and nonsense-mediated mRNA decay. Despite extensive investigation, the complete understanding of eRF3 function have been hampered by the lack of specific anti-eRF3 monoclonal antibodies (Mabs). The purpose of the study was production of recombinant eRF3a/GSPT1, development of anti-eRF3a/GSPT1 Mabs and their utilization for eRF3a/GSPT1 sub-cellular localization. Plasmid encoding C-terminal part of human GSPT1/eRF3a was constructed. Purified protein, which was predominantly present in the inclu... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991360 Tue, 28 Jun 2011 23:00:00 +0100 4991360 http://www.medworm.com/index.php?rid=4991359&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F39%3Frss%3D1 Beta-2 microglobulin (β2m) is the light chain of Class I major histocompatibility complex (MHC-I) complex. β2m is an intrinsically amyloidogenic protein capable of forming amyloid fibrils in vitro and in vivo. β2m displays the typical immunoglobulin-like fold with a disulphide bridge (Cys25–Cys80) cross-linking the two β-sheets. Engineering of the loop comprised between β-strands D and E has shown that mutations in this region affect protein structure, fold stability, folding kinetics and amyloid aggregation properties. Such overall effects have been related to the DE loop backbone structure, which presents a strained conformation in the wild-type (wt) protein, and a type I β-turn in the W60G mutant. Here, we report a biophysical and structural character... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991359 Tue, 28 Jun 2011 23:00:00 +0100 4991359 http://www.medworm.com/index.php?rid=4991358&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F23%3Frss%3D1 Calpain has long been an enigmatic enzyme, although it is involved in a variety of biological phenomena. Recent progress in calpain genetics has highlighted numerous physiological contexts in which the functions of calpain are of great significance. This review focuses on recent findings in the field of calpain genetics and the importance of calpain function. Calpain is an intracellular Ca2+-dependent cysteine protease (EC 3.4.22.17; Clan CA, family C02) found in almost all eukaryotes. It is also present in a few bacteria, but not in archaebacteria. Calpain has limited proteolytic activity; rather, it transforms or modulates the structure and/or activity of its substrates. It is, therefore, referred to as a ‘modulator protease’. Within the human genome, 15 genes (CAPN1-3, CAPN5... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991358 Tue, 28 Jun 2011 23:00:00 +0100 4991358 http://www.medworm.com/index.php?rid=4991357&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F15%3Frss%3D1 Both receptor tyrosine kinases epidermal growth factor receptors (EGFRs) and their ligands are transmembrane proteins. It has been known that ligand binding activates cytoplasmic tyrosine kinase domains of EGFRs, resulting in the transduction of signals for cell proliferation, migration, differentiation or survival. In an EGFRs-ligands system, however, signal transduction occurs not only unidirectionally but also bidirectionally, which is regulated by cell–cell contact and proteolytic cleavage. Recent studies of proteolytic cleavage ‘ectodomain shedding’ of EGFRs and their ligands mediated by membrane-type metalloproteinases, a disintegrin and metalloproteinases have been unveiling novel functions and molecular mechanism of their remnant peptides. In addition, the study o... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991357 Tue, 28 Jun 2011 23:00:00 +0100 4991357 http://www.medworm.com/index.php?rid=4991356&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F5%3Frss%3D1 Physiological alterations occur in many organ systems during pregnancy. These changes are necessary for the adaptation to pregnancy-specific physiological processes in mother and fetus, and the placenta plays a critical role in the maintenance of homeostasis in pregnancy. Dysregulation of these functional feto–maternal interactions leads to severe complications. There have been many attempts to create animal models that mimic the hypertensive disorders of pregnancy, especially pre-eclampsia. In this review, we summarize the physiology of pregnancy and placental function, and discuss the placental gene expression in normal pregnancy. In addition, we assess a number of established animal models focusing on a specific pathogenic mechanism of pre-eclampsia, including genetically modified... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991356 Tue, 28 Jun 2011 23:00:00 +0100 4991356 http://www.medworm.com/index.php?rid=4991355&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F150%2F1%2F1%3Frss%3D1 With the emergence of chemical biology, the use of pharmacological inhibitors in biological research has been expanding. SP600125 is a low-molecular weight compound that has been widely used to inhibit c-Jun-N-terminal kinase (JNK). A recent publication by Tanemura et al. (J. Biochem. 145:345–354, 2009) indicated that SP600125 also inhibits phosphatidylinositol 3-kinase (PI3K) in an isoform-selective fashion: it efficiently inhibited the delta isoform of p110 catalytic subunit (p110), which is primarily expressed in leucocytes, but neither of the ubiquitously expressed isoforms, p110α and p110. Here, I discuss what we learn from such unpredicted off-target effects of pharmacological inhibitors. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4991355 Tue, 28 Jun 2011 23:00:00 +0100 4991355 http://www.medworm.com/index.php?rid=4870465&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F739%3Frss%3D1 Hypothermic preservation of bioartificial liver (BAL) has long been appreciated in BAL storage and transportation. However, the deterioration of cell activity during hypothermia/rewarming limits its clinical use and the complete prevention of hypothermia-induced hepatocyte injury has not been achieved. In this article, a miniaturized BAL that underwent three preservation stages (i.e. pre-incubation, hypothermia and rewarming) was applied as a hypothermic preservation model to locate the protection of several protective agents against hypothermia-induced cell injury. The agents, including vitamin E, schisandrin B, glycyrrhizic acid, N-acetyl-cysteine, ruthenium red, trehalose, anisodamine, fructose-1, 6-diphosphate, cyclosporin A and matrine (Mat), were found to exert their functions at dif... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870465 Thu, 26 May 2011 23:00:00 +0100 4870465 http://www.medworm.com/index.php?rid=4870464&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F731%3Frss%3D1 MutT-related proteins, including Escherichia coli MutT and the human MTH1 (NUDT1), degrade 8-oxo-7, 8-dihydrodeoxyguanosine triphosphate (8-oxo-dGTP) to 8-oxo-dGMP and thereby prevent mutations caused by the misincorporation of 8-oxoguanine into DNA. The human NUDT5, which has an intrinsic activity to cleave ADP sugars to AMP and sugar phosphate, possesses the ability to degrade 8-oxo-dGDP to the monophosphate. Since 8-oxo-dGDP and 8-oxo-dGTP are interconvertible by cellular enzymes, NUDT5 has the potential to prevent errors during DNA replication. The two activities associated with NUDT5 exhibit different pH dependencies; the optimum for the cleavage of ADP ribose is pH 7–9, while that for 8-oxo-dGDPase is around pH 10. The kinetic parameters for the two types of reactions indicated... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870464 Thu, 26 May 2011 23:00:00 +0100 4870464 http://www.medworm.com/index.php?rid=4870463&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F721%3Frss%3D1 MENA, VASP and EVL are members of the ENA/VASP family of proteins and are involved in cytoplasmic actin remodeling. Previously, we found that EVL directly interacts with RAD51, an essential protein in the homologous recombinational repair of double-strand breaks (DSBs) and stimulates the RAD51-mediated recombination reactions in vitro. The EVL-knockdown MCF7 cells exhibited a clear reduction in RAD51-foci formation, suggesting that EVL may function in the DSB repair pathway through RAD51-mediated homologous recombination. However, the DSB repair defects were less significant in the EVL-knockdown cells, implying that two EVL paralogues, MENA and VASP, may complement the EVL function in human cells. Therefore, in the present study, we purified human MENA, VASP and EVL as recombinant proteins... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870463 Thu, 26 May 2011 23:00:00 +0100 4870463 http://www.medworm.com/index.php?rid=4870462&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F713%3Frss%3D1 To evaluate the role of the hydration layer on the protein surface of actomyosin, we compared the effects of urea and guanidine-HCl on the sliding velocities and ATPase activities of the actin-heavy meromyosin (HMM) system. Both chemicals denature proteins, but only urea perturbs the hydration layer. Both the sliding velocity of actin filaments and actin-activated ATPase activity decreased with increasing urea concentrations. The sliding movement was completely inhibited at 1.0 M urea, while actin filaments were bound to HMM molecules fixed on the glass surface. Guanidine-HCl (0–0.05 M) drastically decreased both the sliding velocity and ATPase activation of acto-HMM complexes. Under this condition, actin filaments almost detached from HMM molecules. In contrast, the ATPase activity ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870462 Thu, 26 May 2011 23:00:00 +0100 4870462 http://www.medworm.com/index.php?rid=4870461&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F701%3Frss%3D1 Serine dehydrogenase from Escherichia coli is a homotetrameric enzyme belonging to the short-chain dehydrogenase/reductase (SDR) family. This enzyme catalyses the NADP+-dependent oxidation of serine to 2-aminomalonate semialdehyde. The enzyme shows a stereospecificity for β-(3S)-hydroxy acid as a substrate; however, no stereospecificity was observed at the α-carbon. The structures of the ligand-free SerDH and SerDH–NADP+–phosphate complex were determined at 1.9 and 2.7 Å resolutions, respectively. The overall structure, including the catalytic tetrad of Asn106, Ser134, Tyr147 and Lys151, shows obvious relationships with other members of the SDR family. The structure of the substrate-binding loop and that of the C-terminal region were disordered in the ligand-fr... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870461 Thu, 26 May 2011 23:00:00 +0100 4870461 http://www.medworm.com/index.php?rid=4870460&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F693%3Frss%3D1 The planar cell polarity (PCP) protein, Prickle (Pk), is conserved in invertebrates and vertebrates, and regulates cellular morphogenesis and movement. Vertebrate Pk consists of at least two family members, Pk1 and Pk2, both of which are expressed in the brain; however, their localization and function at synapses remain elusive. Here, we show that Pk2 is expressed mainly in the adult brain and is tightly associated with the postsynaptic density (PSD) fraction obtained by subcellular fractionation. In primary cultured rat hippocampal neurons, Pk2 is colocalized with PSD-95 and synaptophysin at synapses. Moreover, immunoelectron microcopy shows that Pk2 is localized at the PSD of asymmetric synapses in the hippocampal CA1 region. Biochemical assays identified that Pk2 forms a complex with PS... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870460 Thu, 26 May 2011 23:00:00 +0100 4870460 http://www.medworm.com/index.php?rid=4870459&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F685%3Frss%3D1 Fibroblast activation protein (FAP) is a prolyl-cleaving endopeptidase proposed as an anti-cancer drug target. It is necessary to define its cleavage-site specificity to facilitate the identification of its in vivo substrates and to understand its biological functions. We found that the previously identified substrate of FAP, α2-anti-plasmin, is not a robust substrate in vitro. Instead, an intracellular protein, SPRY2, is cleavable by FAP and more suitable for investigation of its substrate specificity in the context of the full-length globular protein. FAP prefers uncharged residues, including small or bulky hydrophobic amino acids, but not charged amino acids, especially acidic residue at P1', P3 and P4 sites. Molecular modelling analysis shows that the substrate-binding site of FA... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870459 Thu, 26 May 2011 23:00:00 +0100 4870459 http://www.medworm.com/index.php?rid=4870458&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F673%3Frss%3D1 Three-dimensional structural model of epoxide hydrolase (PchEHA) from Phanerochaete chrysosporium was constructed based on X-ray structure of Agrobacterium radiobacter AD1 sEH using SWISS-MODEL server. Conserved residues constituting the active site cavity were identified, of which the functional roles of 14 residues were determined by site-directed mutagenesis. In catalytic triad, Asp105 and His308 play a leading role in alkylation and hydrolysis steps, respectively. Distance between Asp105 and epoxide ring of substrate may determine the regiospecificity in the substrate docking model. Asp277 located at the entrance of substrate tunnel is concerned with catalysis but not essential. D307E had the highest activity and lower enantioselectivity among 14 mutants, suggesting Asp307 may be invol... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870458 Thu, 26 May 2011 23:00:00 +0100 4870458 http://www.medworm.com/index.php?rid=4870457&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F665%3Frss%3D1 SpoIIGA is a novel type of membrane-associated aspartic protease that responds to a signal from the forespore by cleaving Pro-E in the mother cell during sporulation of Bacillus subtilis. Very little is known about how SpoIIGA recognizes Pro-E. By co-expressing proteins in Escherichia coli, it was shown that charge reversal substitutions for acidic residues 24 and 25 of Pro-E, and for basic residues 245 and 284 of SpoIIGA, impaired cleavage. These results are consistent with a model predicting possible electrostatic interactions between these residues; however, no charge reversal substitution for residue 245 or residue 284 of SpoIIGA restored cleavage of Pro-E with a charge reversal substitution for residue 24 or residue 25. Bacillus subtilis SpoIIGA cleaved Pro-E orthologs from Bacillus l... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870457 Thu, 26 May 2011 23:00:00 +0100 4870457 http://www.medworm.com/index.php?rid=4870456&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F655%3Frss%3D1 FoF1-ATP synthase is one of the most ubiquitous enzymes; it is found widely in the biological world, including the plasma membrane of bacteria, inner membrane of mitochondria and thylakoid membrane of chloroplasts. However, this enzyme has a unique mechanism of action: it is composed of two mechanical rotary motors, each driven by ATP hydrolysis or proton flux down the membrane potential of protons. The two molecular motors interconvert the chemical energy of ATP hydrolysis and proton electrochemical potential via the mechanical rotation of the rotary shaft. This unique energy transmission mechanism is not found in other biological systems. Although there are other similar man-made systems like hydroelectric generators, FoF1-ATP synthase operates on the nanometre scale and works with extre... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870456 Thu, 26 May 2011 23:00:00 +0100 4870456 http://www.medworm.com/index.php?rid=4870455&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F641%3Frss%3D1 The establishment of a functional brain requires coordinated and stereotyped formation of synapses between neurons. For this, trans-synaptic molecular cues (synaptic organizers) are exchanged between a neuron and its target to organize appropriate synapses. The understanding of signalling mechanisms by which such synaptic organizers lead to synapse formation is just being elucidated. However, recent studies revealed that some of these cues act through receptor protein tyrosine kinases (RPTKs) or phosphatases (RPTPs). Synaptogenic RPTKs and RPTPs pattern synaptic network through affecting local protein–protein binding dynamics, changing the phosphorylation state of signalling cascades, or promoting gene expression. Each RPTK or RPTP has distinct roles in synapse formation, serving at ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870455 Thu, 26 May 2011 23:00:00 +0100 4870455 http://www.medworm.com/index.php?rid=4870454&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F633%3Frss%3D1 Contrary to the long believed hypothesis, it is now evident that breast cancer cells can disseminate from the early phases of the oncogenesis; and that such early disseminated cells sometimes survive at the sites of dissemination and may outgrow after a long latency of years and decades. For cancer cells to leave their origin, they must at least transiently loosen their adhesion with adjacent epithelial cells and stroma, and become motile while avoiding anoikis. Such processes resemble epithelial-mesenchymal transdifferentiation (EMT), which normally takes place in situations such as embryogenesis and wound healing. Interestingly, the occurrence of an EMT-like process in breast cancer cells has been implicated in the generation of cancer stem-like cells, in which TGFβ1 signalling ofte... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870454 Thu, 26 May 2011 23:00:00 +0100 4870454 http://www.medworm.com/index.php?rid=4870453&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F6%2F629%3Frss%3D1 RecQ family helicases are conserved from bacteria to human. Across the species, they are known to be required for protecting genome from various genotoxic stresses. In human, five RecQ-related helicases have been identified and three of them, BLM, WRN and RecQL4, have been shown to be responsible for genetic disorders, Bloom, Werner and Rothmund-Thomson syndrome, respectively, which are characterized by cancer predisposition and premature ageing. RecQL4, the N-terminal portion of which shares similarity with Sld2 known to be required for assembly of a replication complex in yeasts, is unique in that it has been shown to be essential for the initiation phase of normal DNA replication. Recent biochemical characterization demonstrated the 3'–5' DNA helicase activity associated with RecQ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4870453 Thu, 26 May 2011 23:00:00 +0100 4870453 http://www.medworm.com/index.php?rid=4741619&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F619%3Frss%3D1 In this study, we investigated the microtubule-binding activity of zebrafish DCLK (zDCLK) using various deletion mutants and chimeric proteins. The microtubule-binding activity of various mutants of zDCLK was assessed both by immunocytochemical analysis and by biochemical analysis using detergent extraction method. When the kinase domain was removed from zDCLK, the microtubule-binding activity was significantly enhanced. Although the zDCLK(DC + SP) mutant showed a strong microtubule-binding activity, the DC domain alone showed much lower microtubule-binding activity, indicating that the SP domain of zDCLK plays a role in enhancing microtubule-binding activity of the DC domain. These results suggest that both the kinase domain and the SP domain are involved in regulating the microtubule-bin... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741619 Thu, 21 Apr 2011 23:00:00 +0100 4741619 http://www.medworm.com/index.php?rid=4741618&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F609%3Frss%3D1 Trans-translation is an eubacterial quality control system to rescue the stalled ribosome, in which multiple components such as transfer messenger RNA (tmRNA) and Small protein B (SmpB) are involved. However, how these molecules interact with ribosome remains elusive. Here, we report the single molecule analysis of the trans-translation process. We developed a new method to label the functional ribosome, in which a tag protein (the HaloTag protein of 297 amino acids) was fused to the 30S ribosomal protein S2 and covalently labelled with specific ligand (HaloTag ligand), resulting in the stable and specific labelling of ribosome. Ribosomes were anchored onto the glass surface using biotinylated derivative of the Cy3 HaloTag ligand (i.e. biotin–Cy3–ligand), and real-time interact... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741618 Thu, 21 Apr 2011 23:00:00 +0100 4741618 http://www.medworm.com/index.php?rid=4741617&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F601%3Frss%3D1 Differential methods of scanning micro-calorimetry and UV spectrophotometry were used for understanding the interaction of natural anti-tumour antibiotic actinomycin D with cluster sites of native and fragmented DNA during thermal melting. At low (micro-molar) concentrations, the actinomycin molecules penetrate into unwound regions of DNA, but not into the double helix. Moreover, they stabilize the fragmented DNA and increase a total melting point. Actinomycin D interacts with fractions of native DNA even at very low concentrations (at the antibiotic/nucleotide ratio of 1 : 868) and stabilizes the most loose clusters. At high concentrations, it destabilizes the double helix. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741617 Thu, 21 Apr 2011 23:00:00 +0100 4741617 http://www.medworm.com/index.php?rid=4741616&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F591%3Frss%3D1 Nascent polypeptide chains synthesized by membrane bound ribosomes are cotranslationally translocated through and integrated into the endoplasmic reticulum translocon. Hydrophobic segments and positive charges on the chain are critical to halt the ongoing translocation. A marginally hydrophobic segment, which cannot be inserted into the membrane by itself, can be a transmembrane segment depending on its downstream positive charges. In certain conditions, positive charges even 60 residues downstream cause the marginally hydrophobic segment to span the membrane by inducing the segment to slide back from the lumen. Here we systematically examined the effect of a core sugar chain on the fate of a marginally hydrophobic segment using a cell-free translation and translocation system. A sugar cha... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741616 Thu, 21 Apr 2011 23:00:00 +0100 4741616 http://www.medworm.com/index.php?rid=4741615&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F581%3Frss%3D1 In this study, using soaking RNA interference, we found that knockdown of HMG-5 reduced the amount of mtDNA in P0 hermaphrodites, suggesting it as functional orthologue of mammalian TFAM. We also examined the biochemical property of HMG-5 in mammalian cells and in vitro. We found that HMG-5 localized to the mitochondria in human cultured cells and was included in the NP-40-insoluble fraction in which mtDNA and TFAM were enriched. By immunoprecipitation analysis, HMG-5 was found to associate with human mitochondrial DNA (mtDNA) in the cells. In vitro binding experiment also showed that HMG-5 binds to C. elegans mtDNA and plasmid DNA, indicating its feature as a non-specific DNA-binding protein. Furthermore, it was found that HMG-5 can interact with itself. These results demonstrate that HMG... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741615 Thu, 21 Apr 2011 23:00:00 +0100 4741615 http://www.medworm.com/index.php?rid=4741614&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F569%3Frss%3D1 Monoclonal antibodies (mAbs) were prepared to analyse the conformation of human serum albumin (HSA) and its non-enzymatic glycation (NEG) products. We first determined the epitopes of the mAbs using HSA subdomains expressed on the surface of yeast. Each mAb was classified as belonging to one of two groups; Type I mAbs which recognized a single subdomain structure and Type II mAbs which bound to plural subdomains. We analysed the pH-dependent conformational change in HSA. We found that one Type II mAb, HAy2, detected the normal to base form (N-B) transition while the other did not, suggesting that N-B transition occurred around Domain I accompanied by topological isomerization of subdomains without changing the subdomain structure itself. Next, we analysed the conformations of the NEG produ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741614 Thu, 21 Apr 2011 23:00:00 +0100 4741614 http://www.medworm.com/index.php?rid=4741613&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F563%3Frss%3D1 We examined the phosphorylation of mammalian HMGB1 by testing the ability of the cyclin-dependent kinase 5 (Cdk5) to use as substrates native protein, either unmodified or in vivo acetylated and recombinant HMGB1. It turned out that Cdk5 was active on the in vivo acetylated HMGB1 only. We studied the effect of the phosphorylation on the ‘architectural’ properties of the acetylated HMGB1. The treatment with Cdk5 of the acetylated HMGB1 inhibited its capacity to induce DNA end-joining but had no effect on its ability to recognize distorted DNA structures. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741613 Thu, 21 Apr 2011 23:00:00 +0100 4741613 http://www.medworm.com/index.php?rid=4741612&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F551%3Frss%3D1 The predicted protein product of open reading frame slr0328 from Synechocystis sp. PCC 6803, SynPTP, possesses significant amino acid sequence similarity with known low molecular weight protein tyrosine phosphatases (PTPs). To determine the functional properties of this hypothetical protein, open reading frame slr0328 was expressed in Escherichia coli. The purified recombinant protein, SynPTP, displayed its catalytic phosphatase activity towards several tyrosine, but not serine, phosphorylated exogenous protein substrates. The protein phosphatase activity of SynPTP was inhibited by sodium orthovanadate, a known inhibitor of tyrosine phosphatases, but not by okadaic acid, an inhibitor for many serine/threonine phosphatases. Kinetic analysis indicated that the Km and Vmax values for SynPTP t... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741612 Thu, 21 Apr 2011 23:00:00 +0100 4741612 http://www.medworm.com/index.php?rid=4741611&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F539%3Frss%3D1 In this study, we focused on a novel rice plant kinesin, K23, which also belongs to the kinesin-7 subfamily. The biochemical characterization of the K23 motor domain (K23MD) was studied and compared with the rice kinesin K16 and other related kinesins. K23 exhibits ~45-fold (1.3 Pi mol–1site mol–1s–1) lower microtubule-dependent ATPase activity than conventional kinesins, whereas its affinity for microtubules is comparable with conventional kinesins. MgADP-free K23 is unstable compared with the unusually stable MgADP-free K16MD. The enzymatic properties of K23MD are somewhat different from those of K16. We used a fluorescent ATP analogue 2'(3')-O-(N'-methylanthraniloyl)-ATP (mant-ATP) for the kinetic characterization of K23. The fluorescence of mant-ATP was not significan... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741611 Thu, 21 Apr 2011 23:00:00 +0100 4741611 http://www.medworm.com/index.php?rid=4741610&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F529%3Frss%3D1 Accumulation of lipids inside the cell is primarily caused by disorders of lipid metabolism. S-adenosylmethionine synthetase (SAMS) produces SAM, an important methyl donor in various phospholipid methyltransferase reactions catalysed by phosphoethanolamine N-methyltransferase (PMT-1). A gel-based, quantitative proteomic analysis of the RNA interference (RNAi)-mediated inactivation of the pod-2 gene, which encodes acetyl-CoA carboxylase, showed a substantial down-regulation of SAMS-1. Consequently, RNAi of either sams-1 or pmt-1 caused a significant increase in lipid droplet size in the intestine of Caenorhabditis elegans. Lipid droplets exhibited increased triacylglycerol (TG) and decreased phosphatidylcholine (PC) levels, suggesting a reciprocal relationship between TG and PC regulation. ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741610 Thu, 21 Apr 2011 23:00:00 +0100 4741610 http://www.medworm.com/index.php?rid=4741609&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F519%3Frss%3D1 Lon is an ATP-dependent serine protease that plays a significant role in the quality control of proteins in cells, degrading misfolded proteins and certain short-lived regulatory proteins under stresses as such heat-shock and UV irradiation. It is known that some polymers containing phosphate groups regulate enzymatic activity by binding with Lon. We focused on the phospholipids of biological membrane components such as phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and cardiolipin (CL), and examined whether or not liposomes containing these phospholipids regulate the enzymatic activity of Lon. CL-containing liposomes specifically inhibited both the proteolytic and ATPase activities of Lon in a dose-dependent manner. In addition, on pull-down assay, we found that CL-co... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741609 Thu, 21 Apr 2011 23:00:00 +0100 4741609 http://www.medworm.com/index.php?rid=4741608&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F507%3Frss%3D1 Eukaryotic cells can adapt to endoplasmic reticulum (ER) dysfunction by producing diverse signals from the ER to the cytosol or nucleus. These signalling pathways are collectively known as the unfolded protein response (UPR). The canonical branches of the UPR are mediated by three ER membrane-bound proteins: PERK, IRE1 and ATF6. These ER stress transducers basically play important roles in cell survival after ER stress. Recently, novel types of ER stress transducers that share a region of high sequence similarity with ATF6 have been identified. They have a transmembrane domain, which allows them to associate with the ER, and possess a transcription–activation domain and a bZIP domain. These membrane-bound bZIP transcription factors include Luman, OASIS, BBF2H7, CREBH and CREB4. Despi... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741608 Thu, 21 Apr 2011 23:00:00 +0100 4741608 http://www.medworm.com/index.php?rid=4741607&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F499%3Frss%3D1 As a new strategy for drug discovery and development, I focus on drug re-profiling as a way to identify new treatments for diseases. In this strategy, the actions of existing medicines, whose safety and pharmacokinetic effects in humans have already been confirmed clinically and approved for use, are examined comprehensively at the molecular level and the results used for the development of new medicines. This strategy is based on the fact that we still do not understand the underlying mechanisms of action of many existing medicines, and as such the cellular responses that give rise to their main effects and side effects are yet to be elucidated. To this extent, identification of the mechanisms underlying the side effects of medicines offers a means for us to develop safer drugs. The resul... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741607 Thu, 21 Apr 2011 23:00:00 +0100 4741607 http://www.medworm.com/index.php?rid=4741606&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F5%2F495%3Frss%3D1 GPR55 is a seven transmembrane G protein-coupled receptor and was originally identified as a putative third cannabinoid receptor. Recently, lysophosphatidylinositol (LPI) was reported to be a GPR55 ligand. Stimulation of GPR55 by LPI activates G12/13 and Gq/11 proteins, induces phosphorylation of the extracellular signal-regulated kinase and increases intracellular calcium concentration. Lysophospholipids are molecularly quite diverse across species and tissues. A recent report showed that the predominant fatty acyl moiety of LPI in rat brain is stearic acid followed by arachidonic acid. The biological activity of arachidonic acid-containing LPI species towards GPR55 was shown to be markedly higher than that of LPI species containing other fatty acyl groups, suggesting that 2-arachidonolyl... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4741606 Thu, 21 Apr 2011 23:00:00 +0100 4741606 http://www.medworm.com/index.php?rid=4635800&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F487%3Frss%3D1 Coplanar polychlorinated biphenyls included in dioxin-like compounds are bio-accumulated and adversely affect wildlife and human health. Although many researchers have studied the metabolism of PCBs, there have been few reports of the in vitro metabolism of 3,3',4,4',5-pentachlorobiphenyl (PCB126), despite the fact that it has the highest toxicity among PCB congeners. Cytochrome P450 (CYP) 1A1 proteins can metabolize some dioxins and PCBs by hydroxylation, but the activities of human and rat CYP1A1 proteins are very different. The mechanism remains unclear. From our results, rat CYP1A1 metabolized PCB126 into 4-OH-3,3',4',5-tetrachlorobiphenyl and 4-OH-3,3',4',5,5'-pentachlorobiphenyl, but human CYP1A1 did not metabolize. Homology models of the two CYP proteins, and docking studies, showed... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635800 Fri, 25 Mar 2011 00:00:00 +0100 4635800 http://www.medworm.com/index.php?rid=4635799&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F475%3Frss%3D1 The gene cluster involved in producing the cyclic heptadepsipeptide micropeptin was cloned from the genome of the unicellular cyanobacterium Microcystis aeruginosa K-139. Sequencing revealed four genes encoding non-ribosomal peptide synthetases (NRPSs) that are highly similar to the gene cluster involved in cyanopeptolins biosynthesis. According to predictions based on the non-ribosomal consensus code, the order of the mcnABCE NPRS modules was well consistent with that of the biosynthetic assembly of cyclic peptides. The biochemical analysis of a McnBK-139 adenylation domain and the knock-out of mcnC in a micropeptin-producing strain, M. viridis S-70, revealed that the mcn gene clusters were responsible for the production of heptadepsipeptide micropeptins. A detailed comparison of nucleoti... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635799 Fri, 25 Mar 2011 00:00:00 +0100 4635799 http://www.medworm.com/index.php?rid=4635798&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F463%3Frss%3D1 Calmodulin (CaM), a Ca2+-binding protein, is a well-known regulator of various cellular functions. One of the targets of CaM is metabotropic glutamate receptor 7 (mGluR7), which serves as a low-pass filter for glutamate in the pre-synaptic terminal to regulate neurotransmission. Surface plasmon resonance (SPR), circular dichroism (CD) spectroscopy and nuclear magnetic spectroscopy (NMR) were performed to study the structure of the peptides corresponding to the CaM-binding domain of mGluR7 and their interaction with CaM. Unlike well-known CaM-binding peptides, mGluR7 has a random coil structure even in the presence of trifluoroethanol. Moreover, NMR data suggested that the complex between Ca2+/CaM and the mGluR7 peptide has multiple conformations. The mGluR7 peptide has been found to intera... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635798 Fri, 25 Mar 2011 00:00:00 +0100 4635798 http://www.medworm.com/index.php?rid=4635797&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F455%3Frss%3D1 The binding of SopA to the promoter region of its own gene, in which four copies of SopA’s recognition sequence, 5'-CTTTGC-3', are arrayed asymmetrically, was examined in vitro. Titration using electrophoretic mobility shift assay showed that the stoichiometry of SopA protomers to the promoter-region DNA is 4 and that the binding is highly co-operative. The co-operativity was corroborated by EMSA and DNase I footprinting for a number of mutant DNA fragments in which 5'-CTTTGC-3' was changed to 5'-CTTACG-3'. EMSA in the style of circular permutation showed that SopA bends DNA. Mutation at either outermost binding site had a different effect on DNA bending by SopA, reflecting the asymmetry in the arrangement of the binding sites, for which the results of DNase I footprinting were in ag... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635797 Fri, 25 Mar 2011 00:00:00 +0100 4635797 http://www.medworm.com/index.php?rid=4635796&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F443%3Frss%3D1 Eukaryotic typical 2-Cys type peroxiredoxin (Prx) is inactivated by hyperoxidation of the peroxidatic cysteine to a sulphinic acid in a catalytic cycle-dependent manner. This inactivation process has been well documented for cytosolic isoforms of Prx. However, such a hyperoxidative inactivation has not fully been investigated in Prx-4, a secretable endoplasmic reticulum-resident isoform, in spite of being a typical 2-Cys type, and details of this process are reported herein. As has been observed in many peroxiredoxins, the peroxidase activity of Prx-4 was almost completely inhibited in the reaction with t-butyl hydroperoxide. On the other hand, when H2O2 was used as the substrate, the peroxidase activity significantly remained after oxidative damage. In spite of these different consequence... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635796 Fri, 25 Mar 2011 00:00:00 +0100 4635796 http://www.medworm.com/index.php?rid=4635795&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F433%3Frss%3D1 In this study, we examined the role of 3'-untranslated region (3'UTR)-PKG-I messenger RNA (mRNA) in the control of PKG-I expression in vascular smooth muscle cells (VSMCs). Using a 3'-rapid amplification of cDNA ends (RACE) for the amplification of complementary DNA (cDNA) ends, we generated and cloned a 1.2-kb-3'UTR mRNA PKG-I in pGL3 control vector downstream of the luciferase reporter gene. Serial deletions and functional studies revealed that among the deleted constructs, only the 1.2-kb-3'UTR PKG-I mRNA possesses the highest activity in transfected VSMC. Kinetic luciferase assays in the presence of actinomycin D showed that this construct stabilizes luciferase activity compared to the control vector. Sequence analysis of 3'UTR-PKG-I mRNA revealed the existence of four AU-rich regions ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635795 Fri, 25 Mar 2011 00:00:00 +0100 4635795 http://www.medworm.com/index.php?rid=4635794&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F423%3Frss%3D1 In this study, we isolated novel temperature-sensitive (ts) cdc50 mutants whose products were still localized to endosomal/TGN compartments at the non-permissive temperature. Mutant Cdc50 proteins colocalized with Drs2p in endosomal/TGN compartments, and they co-immunoprecipitated with Drs2p. These cdc50-ts mutants exhibited defects in vesicle transport from early endosomes to the TGN as the cdc50 deletion mutant did. These results suggest that mutant Cdc50 proteins could be complexed with Drs2p, but the resulting Cdc50p–Drs2p complex is functionally defective at the non-permissive temperature. Cdc50p may play an important role for phospholipid translocation by Drs2p. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635794 Fri, 25 Mar 2011 00:00:00 +0100 4635794 http://www.medworm.com/index.php?rid=4635793&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F415%3Frss%3D1 In this study, we identified a plant-derived alkaloid, calystegine B3, as a potent specific inhibitor for Man2C1 activity. Biochemical enzyme assay revealed that calystegine B3 was a highly specific inhibitor for Man2C1 among various α-mannosidases prepared from rat liver. Consistent with this in vitro result, an in vivo experiment also showed that treatment of mammalian-derived cultured cells with this compound resulted in drastic change in both structure and quantity of free oligosaccharides in the cytosol, whereas no apparent change was seen in cell-surface oligosaccharides. Calystegine B3 could thus serve as a potent tool for the development of a highly specific in vivo inhibitor for Man2C1. (Source: Journal of Biochemistry) Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635793 Fri, 25 Mar 2011 00:00:00 +0100 4635793 http://www.medworm.com/index.php?rid=4635792&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F405%3Frss%3D1 Overwhelming evidence from chronic myeloid leukaemia (CML) research indicates that patients harbour quiescent CML stem cells that are responsible for blast crisis. While the haematopoietic stem cell (HSC) origin of CML was first suggested over 30 years ago, recently CML-initiating cells beyond HSCs are also being investigated. We have previously isolated fetal liver kinase-1-positive (Flk1+) cells carrying the BCR/ABL fusion gene from the bone marrow of Philadelphia chromosome-positive (Ph+) patients with hemangioblast property. Here, we show that these cells behave abnormally comparing with the hemangioblasts in healthy donors. These Ph+ putative CML hemangioblast up-regulated TGF-β1 and result in activating matrix metalloproteinase-9 to enhance s-KitL and s-ICAM-1 secretion. Further... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635792 Fri, 25 Mar 2011 00:00:00 +0100 4635792 http://www.medworm.com/index.php?rid=4635791&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F395%3Frss%3D1 A novel non-nucleotide fluorescent ATP analogue, N-methylanthraniloylamideethyl triphosphate (MANTTP), was designed and synthesized for kinetic studies with ATPases. The interaction of MANTTP with myosin ATPase was characterized. MANTTP was used as a substrate of myosin ATPase, and acceleration of actin-dependent hydrolysis was observed. The fluorescence property of MANTTP was not greatly affected by its binding to the ATPase site of myosin. In contrast, during MANTTP hydrolysis, significant fluorescence resonance energy transfer (FRET) was observed between MANTTP and intrinsic tryptophan residues in the myosin motor domain. Binding of MANTTP and formation of a ternary complex with a myosin- N-methylanthraniloylamideethyl diphosphate (MANTDP)-Pi analogue, which may mimic ATPase transient s... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635791 Fri, 25 Mar 2011 00:00:00 +0100 4635791 http://www.medworm.com/index.php?rid=4635790&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F389%3Frss%3D1 In this study, we compared the solubilizing effects of arginine with those of other amino acids, salts and a surfactant using alkyl gallates as model drug substances of low aqueous solubility. The solubilizing effects of arginine on the alkyl gallates were distinct compared with those of other amino acids and salts; the effects were even greater than those achieved using a strongly chaotropic guanidinium ion. Transfer free energy of the alkyl gallates from water to arginine solution depended weakly on their dissolution free energy in water, which is in contrast to sodium dodecyl sulphate that showed strong dependence. The present results suggest that arginine solubilizes alkyl gallates through interaction with the aromatic moiety and sodium dodecyl sulphate does so by interacting with alky... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635790 Fri, 25 Mar 2011 00:00:00 +0100 4635790 http://www.medworm.com/index.php?rid=4635789&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F381%3Frss%3D1 Traditionally, ageing has been considered a passive and entropic process, in which damages accumulate on biological macromolecules over time and the accumulated damages lead to a decline in overall physiological functions. However, the discovery of a longevity mutant in the nematode Caenorhabditis elegans has challenged this view. A longevity mutant is a mutant organism, in which a reduction-of-function of a certain gene prolongs the lifespan. Thus, the discovery of longevity mutants has shown the existence of genes, which function to shorten lifespan in wild-type organisms, promoting extensive hunting for longevity-regulating genes in short-lived model organisms, such as yeast, worms and flies. These studies have revealed remarkable conservation of longevity-regulating genes and their net... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635789 Fri, 25 Mar 2011 00:00:00 +0100 4635789 http://www.medworm.com/index.php?rid=4635788&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F361%3Frss%3D1 The Hippo pathway was discovered as a signal transduction pathway that regulates organ size in Drosophila melanogaster. It is composed of three components: cell surface upstream regulators including cell adhesion molecules and cell polarity complexes; a kinase cascade comprising two serine-threonine kinases with regulators and adaptors; and a downstream target, a transcription coactivator. The coactivator mediates the transcription of cell proliferation-promoting and anti-apoptotic genes. The pathway negatively regulates the coactivator to restrict cell proliferation and to promote cell death. Thus, the pathway prevents tissue overgrowth and tumourigenesis. The framework of the pathway is conserved in mammals. A dysfunction of the pathway is frequently detected in human cancers and correla... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635788 Fri, 25 Mar 2011 00:00:00 +0100 4635788 http://www.medworm.com/index.php?rid=4635787&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F4%2F357%3Frss%3D1 Hydrogen sulfide (H2S) has been established as the third gaseous signaling molecule following nitric oxide and carbon monoxide and participates in a variety of cellular functions such as modulation of neuronal transmission, endothelium-dependent vasorelaxation, stimulation of angiogenesis and regulation of insulin release. Although cystathionine β-synthase and cystathionine -lyase have been regarded as the main producers of H2S in many tissues including brain, liver and kidney, Kimura and his colleagues have recently communicated that 3-mercaptopyruvate sulphurtransferase coupled with cysteine (aspartate) aminotransferase is responsible for the production of H2S in the vascular endothelium of the thoracic aorta [Shibuya et al. (2009) J. Biochem. 146, 623–626]. This finding provi... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4635787 Fri, 25 Mar 2011 00:00:00 +0100 4635787 http://www.medworm.com/index.php?rid=4544341&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F311%3Frss%3D1 Peroxisome-proliferator activated receptor α (PPARα) is a ligand-activated transcription factor, playing a key role in several essential pathways including lipid metabolism. Although nuclear localization of PPARα is essential for its transactivation activity, mechanisms underlying intracellular traffics of PPARα remain undefined. We here identify and characterize a nuclear localization signal (NLS) residing in the junction between DNA-binding domain and hinge regions of PPARα. The NLS consists of two basic-amino acid clusters locating in the sequence encompassing amino acid residues at 144–187. We evidently show by mutational analysis that the basic residues in this NLS are essential for the nuclear import. Moreover, the PPARα NLS binds well-known ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4544341 Tue, 22 Feb 2011 00:00:00 +0100 4544341 http://www.medworm.com/index.php?rid=4506548&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F347%3Frss%3D1 Integrins are widely expressed cell surface molecules that mediate cell attachment to extracellular matrix (ECM) proteins. They also interact with molecules on their own membranes, and these cis-interactions play a crucial role in integrin-dependent cellular responses. We herein analysed what molecules interact with β1 integrin during biological events induced by cell attachment to different ECM proteins, using a recently established reaction, the enzyme-mediated activation of radical sources (EMARS). The interactions between β1 integrin and receptor tyrosine kinases including EGFR and ErbB4 reached a peak at 2 h after seeding HeLa S3 cells onto the ECM proteins. The peak of phosphorylation of ErbB4 (at 2 h after seeding the cells onto fibronectin) coincided with the peak of the ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4506548 Tue, 22 Feb 2011 00:00:00 +0100 4506548 http://www.medworm.com/index.php?rid=4506547&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F337%3Frss%3D1 The extracellular domain of tumour necrosis factor (TNF) receptor II fused with the human IgG1 Fc region (TNFRII-Fc), as well as antibodies against TNF, has been used to treat rheumatoid arthritis. However, TNFRII-Fc is less effective than these antibodies in terms of antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against cells bearing TNF on the cell surface. We hypothesized that these activities could be increased by fusing TNFRII with tandemly repeated Fc (TNFRII-Fc-Fc). The affinities of TNFRII-Fc-Fc for soluble TNF-α and transmembrane TNF-α and the TNF-α cytotoxicity-inhibitory activity were as potent as those of TNFRII-Fc. TNFRII-Fc-Fc showed much higher binding avidity for Fc receptors than TNFRII-Fc and was more potent ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4506547 Tue, 22 Feb 2011 00:00:00 +0100 4506547 http://www.medworm.com/index.php?rid=4506546&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F331%3Frss%3D1 Protein kinase C (PKC) is a family of at least 10 isozymes involved in the activation of different signal transduction pathways. The exact function of these isozymes is not known at present. Isozyme-selective inhibitors would be important to explain the function of the different PKCs and are anticipated to have pharmaceutical potential. Here we report that the small organic molecule BAS 02104951 [5-(1,3-benzodioxol-5-ylmethylene)-1-(phenylmethyl)-2,4,6(1H,3H,5H)-pyrimidinetrion], a barbituric acid derivative, inhibited PKC and PKC in vitro (IC50 18 and 36 µM, respectively). BAS 02104951 also inhibited the interaction of PKC with its adaptor protein receptor for activated C-kinase 2 (RACK2) (IC50 28.5 µM). BAS 02104951 also inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-in... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4506546 Tue, 22 Feb 2011 00:00:00 +0100 4506546 http://www.medworm.com/index.php?rid=4506545&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F321%3Frss%3D1 Using dodecyl N-acetylglucosaminide (GlcNAc-C12) as a saccharide primer, we investigated the biosynthetic changes of neolacto-series glycosphingolipids (GSLs) in mouse embryonal carcinoma F9 cells during differentiation induced by retinoic acid plus dibutyryl cyclic AMP (RA/dbcAMP). In the differentiated cells, the glycosylation of GlcNAc-C12 was greatly enhanced. The sugar compositions of glycosylated primers were assigned as Hex-GlcNAc, [Hex]2-GlcNAc, [Hex]2[HexNAc]-GlcNAc, and [NeuAc][Hex]-GlcNAc by liquid chromatography-tandem mass spectrometry. The detection of augmented biosynthesis of endogenous sialylparagloboside indicated that [NeuAc][Hex]-GlcNAc was predicted to be the non-reducing end trisaccharide of sialylparagloboside. The transcription of B3gnt5, B4galt1, Ggta1, Fut4 and St... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4506545 Tue, 22 Feb 2011 00:00:00 +0100 4506545 http://www.medworm.com/index.php?rid=4506544&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F311%3Frss%3D1 Peroxisome-proliferator activated receptor α (PPARα) is a ligand-activated transcription factor, playing a key role in several essential pathways including lipid metabolism. Although nuclear localization of PPARα is essential for its transactivation activity, mechanisms underlying intracellular traffics of PPARα remain undefined. We here identify and characterize a nuclear localization signal (NLS) residing in the junction between DNA-binding domain and hinge regions of PPARα. The NLS consists of two basic-amino acid clusters locating in the sequence encompassing amino acid residues at 144–187. We evidently show by mutational analysis that the basic residues in this NLS are essential for the nuclear import. Moreover, the PPARα NLS binds well-known ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4506544 Tue, 22 Feb 2011 00:00:00 +0100 4506544 http://www.medworm.com/index.php?rid=4506543&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F301%3Frss%3D1 We previously reported that BRG1, an ATPase subunit of SWI/SNF chromatin remodelling complexes, is constitutively expressed and that the alternative ATPase subunit (BRM) is inducibly expressed through differentiation in mammalian cells. In the present study, the regulatory elements that confer constitutive expression on brg1 were explored. First, we analysed the promoter proximal region surrounding its transcriptional start site. Using computer-aided analysis, a TATA-less, GC-rich promoter containing four putative binding sites for Sp1/3 was predicted. One of the putative Sp1/3-binding sites (from –21 to –15 bp) overlapped with a putative YY1-binding site. A gel-shift assay showed that YY1 but not Sp1/3 bound to this sequence and that Sp3 but not Sp1 bound to the other three pr... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4506543 Tue, 22 Feb 2011 00:00:00 +0100 4506543 http://www.medworm.com/index.php?rid=4506542&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F293%3Frss%3D1 In this study, site-directed mutagenesis and molecular modelling methods were integrated to investigate the structural and functional characteristics of QSOX, especially the importance of the three CXXC motifs. Site-directed mutagenesis suggested that the C449–C452 motif was essential for the activity of human QSOX 1b; the C70–C73 motif was fundamental in electron transfer from thiol-containing substrate including reduced proteins, DTT, GSH rather than the phosphine-based thiol reductant TCEP, to the C449–C452 motif; and the C509–C512 motif was not involved in electron transfer during disulphide formation. The different roles of the CXXC motifs indicated that there were discrepant electron transfer pathways for the oxidation of thiol-containing substrates and non-th... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4506542 Tue, 22 Feb 2011 00:00:00 +0100 4506542 http://www.medworm.com/index.php?rid=4506541&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F285%3Frss%3D1 Large scale T-cell expansion and efficient gene transduction are required for adoptive T-cell gene therapy. Based on our previous observations, human peripheral blood mononuclear cells (PBMCs) can be expanded efficiently while conserving a naïve phenotype by stimulating with both recombinant human fibronectin fragment (CH-296) and anti-CD3 monoclonal antibodies. In this article, we explored the possibility of using this co-stimulation method to generate engineered T cells using lentiviral vector. Human PBMCs were stimulated with anti-CD3 together with immobilized CH-296 or anti-CD28 antibody as well as anti-CD3/anti-CD28 conjugated beads and transduced with lentiviral vector simultaneously. Co-stimulation with CH-296 gave superior transduction efficiency than with anti-CD28. Next, PBM... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4506541 Tue, 22 Feb 2011 00:00:00 +0100 4506541 http://www.medworm.com/index.php?rid=4506540&cid=s_32012_60_f&fid=32012&url=http%3A%2F%2Fjb.oxfordjournals.org%2Fcgi%2Fcontent%2Fshort%2F149%2F3%2F275%3Frss%3D1 Here, a novel cDNA encoding a serine/arginine (SR)-rich protein, designated PSR, was isolated from the true slime mold Physarum polycephalum and expressed in Escherichia coli. The deduced amino acid (aa) sequence reveals that PSR contains RS repeats at its C-terminus, similar to the conventional PSRPK substrate ASF/SF2. To study the novel protein, we generated a variety of mutant constructs by PCR and site-directed mutagenesis. Our analysis indicated that the purified recombinant PSR was phosphorylated by PSRPK in vitro and the SR-rich domain (amino acids 460–469) in the PSR protein was required for phosphorylation. In addition, removal of the docking motif (amino acids 424–450) from PSR significantly reduced the overall catalytic efficiency of the phosphorylation reaction. We ... Journal of Biochemistry journals http://www.medworm.com/rss/comments.php?id=4506540 Tue, 22 Feb 2011 00:00:00 +0100 4506540