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 'Developmental Cell' source. Fri, 19 Mar 2010 18:00:49 +0100 http://www.medworm.com/index.php?rid=3374608&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230739%26dopt%3DAbstract Authors: Wilusz CJ, Wilusz J Control of mRNA translation and localization plays an important role in many developmental contexts. In this issue of Developmental Cell, Reveal et al. show through analysis of the oskar mRNA in Drosophila embryos that regulatory elements within mRNAs can act in trans to influence the behavior of other mRNA molecules. PMID: 20230739 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374608 Tue, 16 Mar 2010 00:00:00 +0100 3374608 http://www.medworm.com/index.php?rid=3374607&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230740%26dopt%3DAbstract Authors: Marzluff WF Histone protein synthesis is activated as cells enter S phase to allow packaging of the newly replicated DNA into chromatin. In this issue of Developmental Cell, Takayama and coworkers elucidate a mechanism for silencing histone expression at the end of S phase in S. pombe. Failure to shut off histone expression disrupts centromeric chromatin structure. PMID: 20230740 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374607 Tue, 16 Mar 2010 00:00:00 +0100 3374607 http://www.medworm.com/index.php?rid=3374606&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230741%26dopt%3DAbstract Authors: Fox-Walsh K, Fu XD Pre-mRNA splicing, once thought to be a strictly posttranscriptional event in gene expression, is subject to a multitiered network of regulation. Luco et al. now report in Science that this regulation seems to begin with chromatin modifications, suggesting that the histone code may be a prequel to the splicing code. PMID: 20230741 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374606 Tue, 16 Mar 2010 00:00:00 +0100 3374606 http://www.medworm.com/index.php?rid=3374605&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230742%26dopt%3DAbstract Authors: Koch U, Radtke F In this issue of Developmental Cell, Sakano et al. describe a novel mechanism of how a key lymphocyte transcription factor crosstalks to Notch signaling during embryonic development and thereby selectively inhibits Notch-activated target genes to allow proper left-right patterning. PMID: 20230742 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374605 Tue, 16 Mar 2010 00:00:00 +0100 3374605 http://www.medworm.com/index.php?rid=3374604&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230743%26dopt%3DAbstract Authors: Palacios D, Puri PL During development, skeletal muscles adapt to stage-specific functional and metabolic challenges by switching the expression of specific subset of genes. The mechanism that governs these changes is still enigmatic. In a recent issue of Cell, Messina and coworkers shed light on this issue through the identification of a transcription factor-NFix-that coordinates the switch in gene expression at the transition from embryonic to fetal myoblasts. PMID: 20230743 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374604 Tue, 16 Mar 2010 00:00:00 +0100 3374604 http://www.medworm.com/index.php?rid=3374603&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230744%26dopt%3DAbstract Authors: Puri S, Hebrok M The pancreas has been the subject of intense research due to the debilitating diseases that result from its dysfunction. In this review, we summarize current understanding of the critical tissue interactions and intracellular regulatory events that take place during formation of the pancreas from a small cluster of cells in the foregut domain of the mouse embryo. Importantly, an understanding of principles that govern the development of this organ has equipped us with the means to manipulate both embryonic and differentiated adult cells in the context of regenerative medicine. The emerging area of lineage modulation within the adult pancreas is of particular interest, and this review summarizes recent findings that exemplify how lessons learned from developmen... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374603 Tue, 16 Mar 2010 00:00:00 +0100 3374603 http://www.medworm.com/index.php?rid=3374602&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230745%26dopt%3DAbstract Authors: Swanson CI, Evans NC, Barolo S Enhancers integrate spatiotemporal information to generate precise patterns of gene expression. How complex is the regulatory logic of a typical developmental enhancer, and how important is its internal organization? Here, we examine in detail the structure and function of sparkling, a Notch- and EGFR/MAPK-regulated, cone cell-specific enhancer of the Drosophila Pax2 gene, in vivo. In addition to its 12 previously identified protein-binding sites, sparkling is densely populated with previously unmapped regulatory sequences, which interact in complex ways to control gene expression. One segment is essential for activation at a distance, yet dispensable for other activation functions and for cell type patterning. Unexpectedly, rearranging sparkling... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374602 Tue, 16 Mar 2010 00:00:00 +0100 3374602 http://www.medworm.com/index.php?rid=3374601&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230746%26dopt%3DAbstract Authors: Takayama Y, Mamnun YM, Trickey M, Dhut S, Masuda F, Yamano H, Toda T, Saitoh S Schizosaccharomyces pombe GATA factor Ams2 is responsible for cell cycle-dependent transcriptional activation of all the core histone genes peaking at G1/S phase. Intriguingly, its own protein level also fluctuates concurrently. Here, we show that Ams2 is ubiquitylated and degraded through the SCF (Skp1-Cdc53/Cullin-1-F-box) ubiquitin ligase, in which F box protein Pof3 binds this protein. Ams2 is phosphorylated at multiple sites, which is required for SCF(Pof3)-dependent proteolysis. Hsk1/Cdc7 kinase physically associates with and phosphorylates Ams2. Even mild overexpression of Ams2 induces constitutive histone expression and chromosome instability, and its toxicity is exaggerated when Hsk1 functi... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374601 Tue, 16 Mar 2010 00:00:00 +0100 3374601 http://www.medworm.com/index.php?rid=3374600&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230747%26dopt%3DAbstract Authors: Katis VL, Lipp JJ, Imre R, Bogdanova A, Okaz E, Habermann B, Mechtler K, Nasmyth K, Zachariae W During meiosis, two rounds of chromosome segregation after a single round of DNA replication produce haploid gametes from diploid precursors. At meiosis I, maternal and paternal kinetochores are pulled toward opposite poles, and chiasmata holding bivalent chromosomes together are resolved by cleavage of cohesin's alpha-kleisin subunit (Rec8) along chromosome arms. This creates dyad chromosomes containing a pair of chromatids joined solely by cohesin at centromeres that had resisted cleavage. The discovery that centromeric Rec8 is protected from separase during meiosis I by shugoshin/MEI-S332 proteins that bind PP2A phosphatase suggests that phosphorylation either of separase or cohe... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374600 Tue, 16 Mar 2010 00:00:00 +0100 3374600 http://www.medworm.com/index.php?rid=3374599&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230748%26dopt%3DAbstract Authors: Singla V, Romaguera-Ros M, Garcia-Verdugo JM, Reiter JF Centrosomes and their component centrioles represent the principal microtubule organizing centers of animal cells. Here, we show that the gene underlying orofaciodigital syndrome 1, Ofd1, is a component of the distal centriole that controls centriole length. In the absence of Ofd1, distal regions of centrioles, but not procentrioles, elongate abnormally. These long centrioles are structurally similar to normal centrioles but contain destabilized microtubules with abnormal posttranslational modifications. Ofd1 is also important for centriole distal appendage formation and centriolar recruitment of the intraflagellar transport protein Ift88. To model OFD1 syndrome in embryonic stem cells, we replaced the Ofd1 gene with miss... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374599 Tue, 16 Mar 2010 00:00:00 +0100 3374599 http://www.medworm.com/index.php?rid=3374598&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230749%26dopt%3DAbstract Authors: Burgos PV, Mardones GA, Rojas AL, Dasilva LL, Prabhu Y, Hurley JH, Bonifacino JS Adaptor protein 4 (AP-4) is the most recently discovered and least well-characterized member of the family of heterotetrameric adaptor protein (AP) complexes that mediate sorting of transmembrane cargo in post-Golgi compartments. Herein, we report the interaction of an YKFFE sequence from the cytosolic tail of the Alzheimer's disease amyloid precursor protein (APP) with the mu4 subunit of AP-4. Biochemical and X-ray crystallographic analyses reveal that the properties of the APP sequence and the location of the binding site on mu4 are distinct from those of other signal-adaptor interactions. Disruption of the APP-AP-4 interaction decreases localization of APP to endosomes and enhances gamma-secret... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374598 Tue, 16 Mar 2010 00:00:00 +0100 3374598 http://www.medworm.com/index.php?rid=3374597&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230750%26dopt%3DAbstract We describe here a myeloid population that is defined by expression of the tyrosine kinase Syk, comprises largely M2-polarized mononuclear cells, and robustly expresses angiogenic factors, including VEGF-C/-D and chemokines. These cells stimulate lymphangiogenesis in vivo. Deletion of Syk causes increased chemotractant production, enhanced transmigration, and accumulation in the skin. Ensuing lymphatic hyperplasia and vessel dilation cause the formation of blood-lymphatic shunts. This mechanism does not involve circulating endothelial progenitor cells and demonstrates the potential of hematopoietic cells to control developmental lymphangiogenesis. PAPERFLICK: PMID: 20230750 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374597 Tue, 16 Mar 2010 00:00:00 +0100 3374597 http://www.medworm.com/index.php?rid=3374596&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230751%26dopt%3DAbstract Authors: Sakano D, Kato A, Parikh N, McKnight K, Terry D, Stefanovic B, Kato Y Although the Notch signaling pathway is one of the most intensely studied intracellular signaling pathways, the mechanisms by which Notch signaling regulates transcription remain incompletely understood. Here, we report that B cell leukemia/lymphoma 6 (BCL6), a transcriptional repressor, is a Notch-associated factor. BCL6 is necessary to maintain the expression of Pitx2 in the left lateral plate mesoderm during the patterning of left-right asymmetry in Xenopus embryos. For this process, BCL6 forms a complex with BCL6 corepressor (BCoR) on the promoters of selected Notch target genes such as enhancer of split related 1. BCL6 also inhibits the transcription of these genes by competing for the Notch1 intracellu... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374596 Tue, 16 Mar 2010 00:00:00 +0100 3374596 http://www.medworm.com/index.php?rid=3374595&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230752%26dopt%3DAbstract Authors: Sugimoto K, Jiao Y, Meyerowitz EM Unlike most animal cells, plant cells can easily regenerate new tissues from a wide variety of organs when properly cultured. The common elements that provide varied plant cells with their remarkable regeneration ability are still largely unknown. Here we describe the initial process of Arabidopsis in vitro regeneration, where a pluripotent cell mass termed callus is induced. We demonstrate that callus resembles the tip of a root meristem, even if it is derived from aerial organs such as petals, which clearly shows that callus formation is not a simple reprogramming process backward to an undifferentiated state as widely believed. Furthermore, callus formation in roots, cotyledons, and petals is blocked in mutant plants incapable of lateral ro... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374595 Tue, 16 Mar 2010 00:00:00 +0100 3374595 http://www.medworm.com/index.php?rid=3374594&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230753%26dopt%3DAbstract Authors: Zhang J, Woodhead GJ, Swaminathan SK, Noles SR, McQuinn ER, Pisarek AJ, Stocker AM, Mutch CA, Funatsu N, Chenn A Little is known about the architecture of cellular microenvironments that support stem and precursor cells during tissue development. Although adult stem cell niches are organized by specialized supporting cells, in the developing cerebral cortex, neural stem/precursor cells reside in a neurogenic niche lacking distinct supporting cells. Here, we find that neural precursors themselves comprise the niche and regulate their own development. Precursor-precursor contact regulates beta-catenin signaling and cell fate. In vivo knockdown of N-cadherin reduces beta-catenin signaling, migration from the niche, and neuronal differentiation in vivo. N-cadherin engagement activ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374594 Tue, 16 Mar 2010 00:00:00 +0100 3374594 http://www.medworm.com/index.php?rid=3374593&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230754%26dopt%3DAbstract Authors: Li P, Pashmforoush M, Sucov HM In many experimental models and clinical examples, defects in the differentiation of the second heart field (SHF) and heart outflow tract septation defects are combined, although the mechanistic basis for this relationship has been unclear. We found that as the initial SHF population incorporates into the outflow tract, it is replenished from the surrounding progenitor territory. In retinoic acid (RA) receptor mutant mice, this latter process fails, and the outflow tract is shortened and misaligned as a result. As an additional consequence, the outflow tract is misspecified along its proximal-distal axis, which results in ectopic expression of TGFbeta2 and ectopic mesenchymal transformation of the endocardium. Reduction of TGFbeta2 gene dosage in... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374593 Tue, 16 Mar 2010 00:00:00 +0100 3374593 http://www.medworm.com/index.php?rid=3374592&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230755%26dopt%3DAbstract Authors: Ferretti R, Palumbo V, Di Savino A, Velasco S, Sbroggiò M, Sportoletti P, Micale L, Turco E, Silengo L, Palumbo G, Hirsch E, Teruya-Feldstein J, Bonaccorsi S, Pandolfi PP, Gatti M, Tarone G, Brancaccio M Centrosome abnormalities lead to genomic instability and are a common feature of many cancer cells. Here we show that mutations in morgana/chp-1 result in centrosome amplification and lethality in both Drosophila and mouse, and that the fly centrosome phenotype is fully rescued by the human ortholog of morgana. In mouse cells, morgana forms a complex with Hsp90 and ROCK I and II, and directly binds ROCK II. Morgana downregulation promotes the interaction between ROCK II and nucleophosmin (NPM), leading to an increased ROCK II kinase activity, which results in centrosome a... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374592 Tue, 16 Mar 2010 00:00:00 +0100 3374592 http://www.medworm.com/index.php?rid=3374591&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20230756%26dopt%3DAbstract Authors: Reveal B, Yan N, Snee MJ, Pai CI, Gim Y, Macdonald PM Asymmetric positioning of proteins within cells is crucial for cell polarization and function. Deployment of Oskar protein at the posterior pole of the Drosophila oocyte relies on localization of the oskar mRNA, repression of its translation prior to localization, and finally activation of translation. Translational repression is mediated by BREs, regulatory elements positioned in two clusters near both ends of the oskar mRNA 3' UTR. Here we show that some BREs are bifunctional: both clusters of BREs contribute to translational repression, and the 3' cluster has an additional role in release from BRE-dependent repression. Remarkably, both BRE functions can be provided in trans by an oskar mRNA with wild-type BREs that is it... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3374591 Tue, 16 Mar 2010 00:00:00 +0100 3374591 http://www.medworm.com/index.php?rid=3287105&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159586%26dopt%3DAbstract Authors: Sarraf SA, Harper JW The TRF1 subunit of the shelterin complex controls telomere length by regulating telomerase access to chromosome ends. Work from Zeng et al. (2010) now reveals in atomic detail how a battle between the SCF(FBX4) ubiquitin ligase and the shelterin component TIN2 controls TRF1 abundance and telomere length homeostasis. PMID: 20159586 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287105 Tue, 16 Feb 2010 00:00:00 +0100 3287105 http://www.medworm.com/index.php?rid=3287104&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159587%26dopt%3DAbstract Authors: Cunningham MD, Kassis JA, Pfeifer K In this issue of Developmental Cell, Kernohan et al. link the chromatin regulatory proteins ATRX, MeCP2, CTCF, and cohesin with silencing of H19 and other imprinted genes during critical stages of postnatal brain development, perhaps suggesting a common etiology for several human diseases that exhibit defects in brain development and function. PMID: 20159587 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287104 Tue, 16 Feb 2010 00:00:00 +0100 3287104 http://www.medworm.com/index.php?rid=3287103&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159588%26dopt%3DAbstract Authors: Tomar A, Schlaepfer DD Transmembrane growth factor and integrin matrix receptors form multiprotein signaling complexes with FAK, a cytoplasmic cell motility-associated kinase. In a recent issue of Molecular Cell, Long et al. now show that a PAK-phosphorylated alternate-spliced isoform of the steroid receptor coactivator-3 (SRC-3Delta4) bridges EGFR and FAK, enhancing breast carcinoma cell migration and metastasis. PMID: 20159588 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287103 Tue, 16 Feb 2010 00:00:00 +0100 3287103 http://www.medworm.com/index.php?rid=3287092&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159589%26dopt%3DAbstract Authors: Rosonina E, Manley JL Alternative polyadenylation generates mRNAs with 3' untranscribed regions of different lengths, often affecting transcript stability. Hornyik et al., in this issue of Developmental Cell, and Liu et al. now demonstrate a role for alternative polyadenylation in gene silencing and the regulation of flowering time in Arabidopsis thaliana. PMID: 20159589 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287092 Tue, 16 Feb 2010 00:00:00 +0100 3287092 http://www.medworm.com/index.php?rid=3287091&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159590%26dopt%3DAbstract Authors: Si-Tayeb K, Lemaigre FP, Duncan SA Embryonic development of the liver has been studied intensely, yielding insights that impact diverse areas of developmental and cell biology. Understanding the fundamental mechanisms that control hepatogenesis has also laid the basis for the rational differentiation of stem cells into cells that display many hepatic functions. Here, we review the basic molecular mechanisms that control the formation of the liver as an organ. PMID: 20159590 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287091 Tue, 16 Feb 2010 00:00:00 +0100 3287091 http://www.medworm.com/index.php?rid=3287090&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159591%26dopt%3DAbstract Authors: Kernohan KD, Jiang Y, Tremblay DC, Bonvissuto AC, Eubanks JH, Mann MR, Bérubé NG Human developmental disorders caused by chromatin dysfunction often display overlapping clinical manifestations, such as cognitive deficits, but the underlying molecular links are poorly defined. Here, we show that ATRX, MeCP2, and cohesin, chromatin regulators implicated in ATR-X, RTT, and CdLS syndromes, respectively, interact in the brain and colocalize at the H19 imprinting control region (ICR) with preferential binding on the maternal allele. Importantly, we show that ATRX loss of function alters enrichment of cohesin, CTCF, and histone modifications at the H19 ICR, without affecting DNA methylation on the paternal allele. ATRX also affects cohesin, CTCF, and MeCP2 occupancy within ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287090 Tue, 16 Feb 2010 00:00:00 +0100 3287090 http://www.medworm.com/index.php?rid=3287089&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159592%26dopt%3DAbstract Authors: Zeng Z, Wang W, Yang Y, Chen Y, Yang X, Diehl JA, Liu X, Lei M TRF1 is a critical regulator of telomere length. As such, TRF1 levels are regulated by ubiquitin-dependent proteolysis via an SCF E3 ligase where Fbx4 contributes to substrate specification. Here, we report the crystal structure of the Fbx4-TRF1 complex at 2.4 A resolution. Fbx4 contains an unusual substrate-binding domain that adopts a small GTPase fold. Strikingly, this atypical GTPase domain of Fbx4 binds to a globular domain of TRF1 through an intermolecular beta sheet, instead of recognizing short peptides/degrons as often seen in other F-box protein-substrate complexes. Importantly, mutations in this interface abrogate Fbx4-dependent TRF1 binding and ubiquitination. Furthermore, the data demonstrate that reco... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287089 Tue, 16 Feb 2010 00:00:00 +0100 3287089 http://www.medworm.com/index.php?rid=3287088&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159593%26dopt%3DAbstract Authors: Yoo SK, Deng Q, Cavnar PJ, Wu YI, Hahn KM, Huttenlocher A Cell polarity is crucial for directed migration. Here we show that phosphoinositide 3-kinase (PI(3)K) mediates neutrophil migration in vivo by differentially regulating cell protrusion and polarity. The dynamics of PI(3)K products PI(3,4,5)P(3)-PI(3,4)P(2) during neutrophil migration were visualized in living zebrafish, revealing that PI(3)K activation at the leading edge is critical for neutrophil motility in intact tissues. A genetically encoded photoactivatable Rac was used to demonstrate that localized activation of Rac is sufficient to direct migration with precise temporal and spatial control in vivo. Similar stimulation of PI(3)K-inhibited cells did not direct migration. Localized Rac activation rescued membrane ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287088 Tue, 16 Feb 2010 00:00:00 +0100 3287088 http://www.medworm.com/index.php?rid=3287079&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159594%26dopt%3DAbstract Authors: Ko HW, Norman RX, Tran J, Fuller KP, Fukuda M, Eggenschwiler JT Recent findings indicate that mammalian Sonic hedgehog (Shh) signal transduction occurs within primary cilia, although the cell biological mechanisms underlying both Shh signaling and ciliogenesis have not been fully elucidated. We show that an uncharacterized TBC domain-containing protein, Broad-minded (Bromi), is required for high-level Shh responses in the mouse neural tube. We find that Bromi controls ciliary morphology and proper Gli2 localization within the cilium. By use of a zebrafish model, we further show that Bromi is required for proper association between the ciliary membrane and axoneme. Bromi physically interacts with cell cycle-related kinase (CCRK), whose Chlamydomonas homolog regulates flagellar ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287079 Tue, 16 Feb 2010 00:00:00 +0100 3287079 http://www.medworm.com/index.php?rid=3287078&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159595%26dopt%3DAbstract Authors: Kitamura E, Tanaka K, Komoto S, Kitamura Y, Antony C, Tanaka TU In early mitosis, microtubules can be generated at kinetochores as well as at spindle poles. However, the role and regulation of kinetochore-derived microtubules have been unclear. In general, metaphase spindle microtubules are oriented such that their plus ends bind to kinetochores. However, we now have evidence that, during early mitosis in budding yeast, microtubules are generated at kinetochores with distal plus ends. These kinetochore-derived microtubules interact along their length with microtubules that extend from a spindle pole, facilitating kinetochore loading onto the lateral surface of spindle pole microtubules. Once kinetochores are loaded, microtubules are no longer generated at kinetochores, and tho... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287078 Tue, 16 Feb 2010 00:00:00 +0100 3287078 http://www.medworm.com/index.php?rid=3287077&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159596%26dopt%3DAbstract Authors: Umulis DM, Shimmi O, O'Connor MB, Othmer HG Advances in image acquisition and informatics technology have led to organism-scale spatiotemporal atlases of gene expression and protein distributions. To maximize the utility of this information for the study of developmental processes, a new generation of mathematical models is needed for discovery and hypothesis testing. Here, we develop a data-driven, geometrically accurate model of early Drosophila embryonic bone morphogenetic protein (BMP)-mediated patterning. We tested nine different mechanisms for signal transduction with feedback, eight combinations of geometry and gene expression prepatterns, and two scale-invariance mechanisms for their ability to reproduce proper BMP signaling output in wild-type and mutant embryos. We f... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287077 Tue, 16 Feb 2010 00:00:00 +0100 3287077 http://www.medworm.com/index.php?rid=3287076&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159597%26dopt%3DAbstract Authors: Tian Y, Yuan L, Goss AM, Wang T, Yang J, Lepore JJ, Zhou D, Schwartz RJ, Patel V, Cohen ED, Morrisey EE Little is understood about the molecular mechanisms underlying the morphogenesis of the posterior pole of the heart. Here we show that Wnt2 is expressed specifically in the developing inflow tract mesoderm, which generates portions of the atria and atrio-ventricular canal. Loss of Wnt2 results in defective development of the posterior pole of the heart, resulting in a phenotype resembling the human congenital heart syndrome complete common atrio-ventricular canal. The number and proliferation of posterior second heart field progenitors is reduced in Wnt2(-/-) mutants. Moreover, these defects can be rescued in a temporally restricted manner through pharmacological inhibition ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287076 Tue, 16 Feb 2010 00:00:00 +0100 3287076 http://www.medworm.com/index.php?rid=3287075&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159598%26dopt%3DAbstract Authors: Yu J, Zheng Y, Dong J, Klusza S, Deng WM, Pan D The Hippo signaling pathway regulates organ size and tissue homeostasis from Drosophila to mammals. Central to this pathway is a kinase cascade wherein Hippo (Hpo), in complex with Salvador (Sav), phosphorylates and activates Warts (Wts), which in turn phosphorylates and inactivates the Yorkie (Yki) oncoprotein, known as the YAP coactivator in mammalian cells. The FERM domain proteins Merlin (Mer) and Expanded (Ex) are upstream components that regulate Hpo activity through unknown mechanisms. Here we identify Kibra as another upstream component of the Hippo signaling pathway. We show that Kibra functions together with Mer and Ex in a protein complex localized to the apical domain of epithelial cells, and that this protein complex... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287075 Tue, 16 Feb 2010 00:00:00 +0100 3287075 http://www.medworm.com/index.php?rid=3287074&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159599%26dopt%3DAbstract Authors: Genevet A, Wehr MC, Brain R, Thompson BJ, Tapon N The Salvador (Sav)/Warts (Wts)/Hippo (Hpo) (SWH) network controls tissue growth by inhibiting cell proliferation and promoting apoptosis. The core of the pathway consists of a MST and LATS family kinase cascade that ultimately phosphorylates and inactivates the YAP/Yorkie (Yki) transcription coactivator. The FERM domain proteins Merlin (Mer) and Expanded (Ex) represent one mode of upstream regulation controlling pathway activity. Here, we identify Kibra as a member of the SWH network. Kibra, which colocalizes and associates with Mer and Ex, also promotes the Mer/Ex association. Furthermore, the Kibra/Mer association is conserved in human cells. Finally, Kibra complexes with Wts and kibra depletion in tissue culture cells induce... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287074 Tue, 16 Feb 2010 00:00:00 +0100 3287074 http://www.medworm.com/index.php?rid=3287073&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159600%26dopt%3DAbstract Authors: Baumgartner R, Poernbacher I, Buser N, Hafen E, Stocker H The conserved Hippo kinase pathway plays a pivotal role in organ size control and tumor suppression by restricting proliferation and promoting apoptosis. Whereas the function of the core kinase cascade, consisting of the serine/threonine kinases Hippo and Warts, in phosphorylating and thereby inactivating the transcriptional coactivator Yorkie is well established, much less is known about the upstream events that regulate Hippo signaling activity. The FERM domain proteins Expanded and Merlin appear to represent two different signaling branches that feed into the Hippo pathway. Signaling by the atypical cadherin Fat may act via Expanded, but how Merlin is regulated has remained elusive. Here, we show that the WW domain p... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287073 Tue, 16 Feb 2010 00:00:00 +0100 3287073 http://www.medworm.com/index.php?rid=3287072&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159601%26dopt%3DAbstract Authors: Doupé DP, Klein AM, Simons BD, Jones PH Typical murine epidermis has a patterned structure, seen clearly in ear skin, with regular columns of differentiated cells overlying the proliferative basal layer. It has been proposed that each column is a clonal epidermal proliferative unit maintained by a central stem cell and its transit amplifying cell progeny. An alternative hypothesis is that proliferating basal cells have random fate, the probability of generating cycling or differentiated cells being balanced so homeostasis is achieved. The stochastic model seems irreconcilable with an ordered tissue. Here we use lineage tracing to reveal that basal cells generate clones with highly irregular shapes that contribute progeny to multiple columns. Basal cell fate and cell cycle... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287072 Tue, 16 Feb 2010 00:00:00 +0100 3287072 http://www.medworm.com/index.php?rid=3287071&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20159602%26dopt%3DAbstract Authors: Robinson MS, Sahlender DA, Foster SD We have developed a method for rapidly inactivating proteins with rapamycin-induced heterodimerization. Cells were stably transfected with siRNA-resistant, FKBP-tagged subunits of the adaptor protein (AP) complexes of clathrin-coated vesicles (CCVs), together with an FKBP and rapamycin-binding domain-containing construct with a mitochondrial targeting signal. Knocking down the endogenous subunit with siRNA, and then adding rapamycin, caused the APs to be rerouted to mitochondria within seconds. Rerouting AP-2 to mitochondria effectively abolished clathrin-mediated endocytosis of transferrin. In cells with rerouted AP-1, endocytosed cation-independent mannose 6-phosphate receptor (CIMPR) accumulated in a peripheral compartment, and isolated ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3287071 Tue, 16 Feb 2010 00:00:00 +0100 3287071 http://www.medworm.com/index.php?rid=3280325&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20153262%26dopt%3DAbstract In this study, we investigate the role of the ubiquitin ligase RNF8 during spermatogenesis and find that RNF8-deficient mice are proficient in meiotic sex chromosome inactivation (MSCI) but deficient in global nucleosome removal. Moreover, we show that RNF8-dependent histone ubiquitination induces H4K16 acetylation, which may be an initial step in nucleosome removal. Thus, our results show that RNF8 plays an important role during spermatogenesis through histone ubiquitination, resulting in trans-histone acetylation and global nucleosome removal. PMID: 20153262 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280325 Wed, 10 Feb 2010 00:00:00 +0100 3280325 http://www.medworm.com/index.php?rid=3280342&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152170%26dopt%3DAbstract Authors: Copp AJ, Greene ND Mammalian neurulation is completed when the dorsolateral neural folds bend inwards, their tips make adhesive contacts across the midline, and the epithelia remodel to create a closed neural tube. Two recent papers (one by Camerer et al. in this issue of Developmental Cell) demonstrate a vital role for protease-activated G protein-coupled receptor signaling in these late closure events, opening up new avenues for exploring the molecular basis of mammalian neural tube morphogenesis. PMID: 20152170 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280342 Tue, 19 Jan 2010 00:00:00 +0100 3280342 http://www.medworm.com/index.php?rid=3280341&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152171%26dopt%3DAbstract Authors: Fingleton B, Lynch CC Matrix metalloproteinases are well known for their key roles in the processing of extracellular matrix and nonmatrix molecules. Recently, a new theme of proteolysis-independent roles for metalloproteinases has emerged, with a paper from Gonzalo et al. in this issue of Developmental Cell providing an illustration. PMID: 20152171 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280341 Tue, 19 Jan 2010 00:00:00 +0100 3280341 http://www.medworm.com/index.php?rid=3280340&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152172%26dopt%3DAbstract Authors: Dressler GR Cells remember established patterns of gene expression through rounds of cell division despite dynamic changes in genomic chromatin structure. Two recent studies in Molecular Cell and Nature Medicine, broadly impacting on epigenetic gene regulation and disease, address how cells remember and suggest that both histone methyltransferases and locus specific DNA binding proteins can mark transcribed genes for reactivation after mitosis. PMID: 20152172 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280340 Tue, 19 Jan 2010 00:00:00 +0100 3280340 http://www.medworm.com/index.php?rid=3280339&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152173%26dopt%3DAbstract Authors: Kaaij LJ, Ketting RF RNAi is essential for pericentromeric heterochromatic formation in S. pombe, and although Dcr1, the initiator protein of this process, has been biochemically well described, its subcellular localization has remained elusive. In this issue of Developmental Cell, Emmerth et al. now show that Dcr1 is dynamically shuttling between nucleus and cytoplasm, adding new insight into the subcellular mechanics of RNAi. PMID: 20152173 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280339 Tue, 19 Jan 2010 00:00:00 +0100 3280339 http://www.medworm.com/index.php?rid=3280338&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152174%26dopt%3DAbstract Authors: Morrisey EE, Hogan BL The mammalian respiratory system-the trachea and the lungs-arises from the anterior foregut through a sequence of morphogenetic events involving reciprocal endodermal-mesodermal interactions. The lung itself consists of two highly branched, tree-like systems-the airways and the vasculature-that develop in a coordinated way from the primary bud stage to the generation of millions of alveolar gas exchange units. We are beginning to understand some of the molecular and cellular mechanisms that underlie critical processes such as branching morphogenesis, vascular development, and the differentiation of multipotent progenitor populations. Nevertheless, many gaps remain in our knowledge, the filling of which is essential for understanding respiratory disorders,... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280338 Tue, 19 Jan 2010 00:00:00 +0100 3280338 http://www.medworm.com/index.php?rid=3280337&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152175%26dopt%3DAbstract We report an unexpected role for protease signaling in neural tube closure and the formation of the central nervous system. Mouse embryos lacking protease-activated receptors 1 and 2 showed defective hindbrain and posterior neuropore closure and developed exencephaly and spina bifida, important human congenital anomalies. Par1 and Par2 were expressed in surface ectoderm, and Par2 was expressed selectively along the line of closure. Ablation of G(i/z) and Rac1 function in these Par2-expressing cells disrupted neural tube closure, further implicating G protein-coupled receptors and identifying a likely effector pathway. Cluster analysis of protease and Par2 expression patterns revealed a group of membrane-tethered proteases often coexpressed with Par2. Among these, matriptase activated Par2 ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280337 Tue, 19 Jan 2010 00:00:00 +0100 3280337 http://www.medworm.com/index.php?rid=3280336&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152176%26dopt%3DAbstract Authors: Zovein AC, Luque A, Turlo KA, Hofmann JJ, Yee KM, Becker MS, Fassler R, Mellman I, Lane TF, Iruela-Arispe ML Maintenance of single-layered endothelium, squamous endothelial cell shape, and formation of a patent vascular lumen all require defined endothelial cell polarity. Loss of beta1 integrin (Itgb1) in nascent endothelium leads to disruption of arterial endothelial cell polarity and lumen formation. The loss of polarity is manifested as cuboidal-shaped endothelial cells with dysregulated levels and mislocalization of normally polarized cell-cell adhesion molecules, as well as decreased expression of the polarity gene Par3 (pard3). beta1 integrin and Par3 are both localized to the endothelial layer, with preferential expression of Par3 in arterial endothelium. Luminal occlus... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280336 Tue, 19 Jan 2010 00:00:00 +0100 3280336 http://www.medworm.com/index.php?rid=3280335&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152177%26dopt%3DAbstract We report that occludin, a transmembrane protein, is localized at the leading edge of migrating cells and regulates directional cell migration. During migration, occludin knockdown disrupted accumulation of aPKC-Par3 and PATJ at the leading edge, and led to a disorganized microtubule network and defective reorientation of the microtubule organization center (MTOC). Phosphorylation of occludin at tyrosine 473 residue allowed recruitment of p85alpha to the leading edge via association with its C-terminal SH2 domain. Loss of occludin attenuated activation of PI3K, leading to disorganization of the actin cytoskeleton and reduced cell protrusions. Our data indicate that occludin is required for the leading-edge localization of polarity proteins aPKC-Par3 and PATJ and promotes cell protrusion by... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280335 Tue, 19 Jan 2010 00:00:00 +0100 3280335 http://www.medworm.com/index.php?rid=3280334&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152178%26dopt%3DAbstract Authors: Fernandes I, Chanut-Delalande H, Ferrer P, Latapie Y, Waltzer L, Affolter M, Payre F, Plaza S The zona pellucida domain (ZPD) defines a conserved family of membrane-anchored matrix proteins that are, as yet, poorly characterized with respect to their functions during development. Using genetic approaches in flies, we show here that a set of eight ZPD proteins is required for the localized reorganization of embryonic epidermal cells during morphogenesis. Despite varying degrees of sequence conservation, these ZPD proteins exert specific and nonredundant functions in the remodeling of epidermal cell shape. Each one accumulates in a restricted subregion of the apical compartment, where it organizes local interactions between the membrane and the extracellular matrix. In addition,... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280334 Tue, 19 Jan 2010 00:00:00 +0100 3280334 http://www.medworm.com/index.php?rid=3280333&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152179%26dopt%3DAbstract Authors: Gonzalo P, Guadamillas MC, Hernández-Riquer MV, Pollán A, Grande-García A, Bartolomé RA, Vasanji A, Ambrogio C, Chiarle R, Teixidó J, Risteli J, Apte SS, Del Pozo MA, Arroyo AG Cell fusion is essential for fertilization, myotube formation, and inflammation. Macrophages fuse under various circumstances, but the molecular signals involved in the distinct steps of their fusion are not fully characterized. Using null mice and derived cells, we show that the protease MT1-MMP is necessary for macrophage fusion during osteoclast and giant-cell formation in vitro and in vivo. Specifically, MT1-MMP is required for lamellipodia formation and for proper cell morphology and motility of bone marrow myeloid progenitors prior to membrane fusion. These functions of MT... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280333 Tue, 19 Jan 2010 00:00:00 +0100 3280333 http://www.medworm.com/index.php?rid=3280332&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152180%26dopt%3DAbstract Authors: Radhakrishnan SK, Pritchard S, Viollier PH NAD(H)-binding proteins play important roles in cell-cycle and developmental signaling in eukaryotes. We identified a bifunctional NAD(H)-binding regulator (KidO) that integrates cell-fate signaling with cytokinesis in the bacterium Caulobacter crescentus. KidO stimulates the DivJ kinase and directly acts on the cytokinetic tubulin, FtsZ, to tune cytokinesis with the cell cycle. At the G1-->S transition, DivJ concomitantly signals the ClpXP-dependent degradation of KidO and CtrA, a cell-cycle transcriptional regulator/DNA replication inhibitor. This proteolytic event directs KidO and CtrA into oscillatory cell-cycle abundance patterns that coordinately license replication and cytokinesis. KidO resembles NAD(P)H-dependent oxidoreduc... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280332 Tue, 19 Jan 2010 00:00:00 +0100 3280332 http://www.medworm.com/index.php?rid=3280331&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152181%26dopt%3DAbstract In this study, we have analyzed the subcellular localization of Dcr1 and found that it accumulates in the nucleus and is enriched at the nuclear periphery. Nuclear accumulation of Dcr1 depends on a short motif that impedes nuclear export promoted by the double-stranded RNA binding domain of Dcr1. Absence of this motif renders Dcr1 mainly cytoplasmic and is accompanied by remarkable changes in gene expression and failure to assemble heterochromatin. Our findings suggest that Dicer proteins are shuttling proteins and that the steady-state subcellular levels can be shifted toward either compartment. PMID: 20152181 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280331 Tue, 19 Jan 2010 00:00:00 +0100 3280331 http://www.medworm.com/index.php?rid=3280330&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152182%26dopt%3DAbstract Authors: Wang J, Weaver IC, Gauthier-Fisher A, Wang H, He L, Yeomans J, Wondisford F, Kaplan DR, Miller FD Increasing evidence indicates that epigenetic changes regulate cell genesis. Here, we ask about neural precursors, focusing on CREB binding protein (CBP), a histone acetyltransferase that, when haploinsufficient, causes Rubinstein-Taybi syndrome (RTS), a genetic disorder with cognitive dysfunction. We show that neonatal cbp(+/-) mice are behaviorally impaired, displaying perturbed vocalization behavior. cbp haploinsufficiency or genetic knockdown with siRNAs inhibited differentiation of embryonic cortical precursors into all three neural lineages, coincident with decreased CBP binding and histone acetylation at promoters of neuronal and glial genes. Inhibition of histone deacetyla... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280330 Tue, 19 Jan 2010 00:00:00 +0100 3280330 http://www.medworm.com/index.php?rid=3280329&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152183%26dopt%3DAbstract Authors: Weng M, Golden KL, Lee CY To ensure normal development and maintenance of homeostasis, the extensive developmental potential of stem cells must be functionally distinguished from the limited developmental potential of transit amplifying cells. Yet the mechanisms that restrict the developmental potential of transit amplifying cells are poorly understood. Here we show that the evolutionarily conserved transcription factor dFezf/Earmuff (Erm) functions cell-autonomously to maintain the restricted developmental potential of the intermediate neural progenitors generated by type II neuroblasts in Drosophila larval brains. Although erm mutant intermediate neural progenitors are correctly specified and show normal apical-basal cortical polarity, they can dedifferentiate back into a ne... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280329 Tue, 19 Jan 2010 00:00:00 +0100 3280329 http://www.medworm.com/index.php?rid=3280328&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152184%26dopt%3DAbstract Authors: Gonzalez-Quevedo R, Lee Y, Poss KD, Wilkinson DG Precise regulation of neurogenesis is achieved in specific regions of the vertebrate nervous system by formation of distinct neurogenic and nonneurogenic zones. We have investigated how neurogenesis becomes confined to zones adjacent to rhombomere boundaries in the zebrafish hindbrain. The nonneurogenic zone at segment centers comprises a distinct progenitor population that expresses fibroblast growth factor (fgfr) 2, erm, sox9b, and the retinoic acid degrading enzyme, cyp26b1. FGF receptor activation upregulates expression of these genes and inhibits neurogenesis in segment centers. Cyp26 activity is a key effector inhibiting neuronal differentiation, suggesting antagonistic interactions with retinoid signaling. We identify the... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280328 Tue, 19 Jan 2010 00:00:00 +0100 3280328 http://www.medworm.com/index.php?rid=3280327&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152185%26dopt%3DAbstract Authors: Hasson P, Delaurier A, Bennett M, Grigorieva E, Naiche LA, Papaioannou VE, Mohun TJ, Logan MP Proper functioning of the musculoskeletal system requires the precise integration of bones, muscles, and tendons. Complex morphogenetic events ensure that these elements are linked together in the appropriate three-dimensional configuration. It has been difficult, however, to tease apart the mechanisms that regulate tissue morphogenesis. We find that deletion of Tbx5 in forelimbs (or Tbx4 in hindlimbs) specifically affects muscle and tendon patterning without disrupting skeletal development, thus suggesting that distinct cues regulate these processes. We identify muscle connective tissue as the site of action of these transcription factors and show that N-Cadherin and beta-Catenin are... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280327 Tue, 19 Jan 2010 00:00:00 +0100 3280327 http://www.medworm.com/index.php?rid=3280326&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20152186%26dopt%3DAbstract This article describes the characterization of the Drosophila matrix metalloprotease Mmp2 as an extracellular inhibitor of FGF morphogenetic function. Mmp2 expression in the developing air sac is controlled by the Drosophila FGF homolog Branchless and then participates in a negative feedback and lateral inhibition mechanism that defines the precise pattern of FGF signaling. The signaling function for MMPs described here may not be limited to branching morphogenesis processes. PMID: 20152186 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3280326 Tue, 19 Jan 2010 00:00:00 +0100 3280326 http://www.medworm.com/index.php?rid=3189552&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20079695%26dopt%3DAbstract We report the identification of an activity for FPA in controlling mRNA 3' end formation. We show that FPA functions redundantly with FCA, another RNA binding protein that controls flowering and RNA silencing, to control the expression of alternatively polyadenylated antisense RNAs at the locus encoding the floral repressor FLC. In addition, we show that defective 3' end formation at an upstream RNA polymerase II-dependent gene explains the apparent derepression of the AtSN1 retroelement in fpa mutants. Transcript readthrough accounts for the absence of changes in DNA methylation and siRNA abundance at AtSN1 in fpa mutants, and this may explain other examples of epigenetic transitions not associated with chromatin modification. HIGHLIGHTS: Spen family proteins can control pre-mRNA processi... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3189552 Wed, 13 Jan 2010 00:00:00 +0100 3189552 http://www.medworm.com/index.php?rid=3164654&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059942%26dopt%3DAbstract Authors: van der Heijden GW, Bortvin A Repression of transposable elements is crucial for the survival of germ cells. In this issue of Developmental Cell, Shoji et al. provide evidence that a Tudor domain protein TDRD9 partners with MIWI2 to specifically silence LINE-1 transposons in the fetal germline of male mice. PMID: 20059942 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164654 Tue, 01 Dec 2009 00:00:00 +0100 3164654 http://www.medworm.com/index.php?rid=3164653&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059943%26dopt%3DAbstract Authors: Reggiori F, Tooze SA Autophagosomes are large double-membrane vesicles that enclose cytoplasmic components targeting them for degradation. Two recent reports reveal that phagophores, the autophagosome precursors, are surrounded by and connected to rough endoplasmic reticulum (ER) membranes. These results shed light on how membranes may be supplied and reorganized for autophagosomal biogenesis. PMID: 20059943 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164653 Tue, 01 Dec 2009 00:00:00 +0100 3164653 http://www.medworm.com/index.php?rid=3164652&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059944%26dopt%3DAbstract Authors: Kaldis P, Pagano M Previously, the connection between cell proliferation and Wnt signaling focused on transcriptional activation of cyclin D1 and c-myc, which control the G1/S transition of the cell cycle. In this issue of Developmental Cell, the Niehrs group demonstrates mitotic activation of Wnt signaling by a novel Cdk/cyclin complex containing Cdk14 (PFTK1) and cyclin Y. PMID: 20059944 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164652 Tue, 01 Dec 2009 00:00:00 +0100 3164652 http://www.medworm.com/index.php?rid=3164651&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059945%26dopt%3DAbstract Authors: Jones KA Moellering et al. recently reported that a cell-permeable "stapled" synthetic peptide of the Notch coactivator Mastermind is a potent dominant-negative inhibitor of oncogenic Notch signaling in T cell acute lymphoblastic leukemia. This new class of inhibitor may find broad utility in blocking protein-protein interactions that underlie many human diseases. PMID: 20059945 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164651 Tue, 01 Dec 2009 00:00:00 +0100 3164651 http://www.medworm.com/index.php?rid=3164650&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059946%26dopt%3DAbstract Authors: Toker A In this issue of Developmental Cell, Suizu et al. (2009) describe a new mechanism for posttranslational regulation of the Akt serine/threonine protein kinase involving ubiquitination. They show that the E3 ubiquitin ligase TTC3 modifies phosphorylated and activated Akt and thereby promotes its degradation by the proteasome in the nucleus. PMID: 20059946 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164650 Tue, 01 Dec 2009 00:00:00 +0100 3164650 http://www.medworm.com/index.php?rid=3164649&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059947%26dopt%3DAbstract Authors: Dunwoodie SL Hypoxia inducible factor (HIF) is a transcription factor that acts in low-oxygen conditions. The cellular response to HIF activation is transcriptional upregulation of a large group of genes. Some target genes promote anaerobic metabolism to reduce oxygen consumption, while others "alleviate" hypoxia by acting non-cell-autonomously to extend and modify the surrounding vasculature. Although hypoxia is often thought of as being a pathological phenomenon, the mammalian embryo in fact develops in a low-oxygen environment, and in this context HIF has additional responsibilities. This review describes how low oxygen and HIF affect gene expression, cell behavior, and ultimately morphogenesis of the embryo and placenta. PMID: 20059947 [PubMed - in process] (Source: De... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164649 Tue, 01 Dec 2009 00:00:00 +0100 3164649 http://www.medworm.com/index.php?rid=3164648&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059948%26dopt%3DAbstract Authors: Shoji M, Tanaka T, Hosokawa M, Reuter M, Stark A, Kato Y, Kondoh G, Okawa K, Chujo T, Suzuki T, Hata K, Martin SL, Noce T, Kuramochi-Miyagawa S, Nakano T, Sasaki H, Pillai RS, Nakatsuji N, Chuma S Host-defense mechanisms against transposable elements are critical to protect the genome information. Here we show that tudor-domain containing 9 (Tdrd9) is essential for silencing Line-1 retrotransposon in the mouse male germline. Tdrd9 encodes an ATPase/DExH-type helicase, and its mutation causes male sterility showing meiotic failure. In Tdrd9 mutants, Line-1 was highly activated and piwi-interacting small RNAs (piRNAs) corresponding to Line-1 were increased, suggesting that feedforward amplification operates in the mutant. In fetal testes, Tdrd9 mutation causes Line-1 desilencing... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164648 Tue, 01 Dec 2009 00:00:00 +0100 3164648 http://www.medworm.com/index.php?rid=3164647&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059949%26dopt%3DAbstract Authors: Davidson G, Shen J, Huang YL, Su Y, Karaulanov E, Bartscherer K, Hassler C, Stannek P, Boutros M, Niehrs C Low-density lipoprotein receptor related proteins 5 and 6 (LRP5/6) are transmembrane receptors that initiate Wnt/beta-catenin signaling. Phosphorylation of PPPSP motifs in the LRP6 cytoplasmic domain is crucial for signal transduction. Using a kinome-wide RNAi screen, we show that PPPSP phosphorylation requires the Drosophila Cyclin-dependent kinase (CDK) L63. L63 and its vertebrate homolog PFTK are regulated by the membrane tethered G2/M Cyclin, Cyclin Y, which mediates binding to and phosphorylation of LRP6. As a consequence, LRP6 phosphorylation and Wnt/beta-catenin signaling are under cell cycle control and peak at G2/M phase; knockdown of the mitotic regulator CDC25/... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164647 Tue, 01 Dec 2009 00:00:00 +0100 3164647 http://www.medworm.com/index.php?rid=3164646&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059950%26dopt%3DAbstract Authors: Suizu F, Hiramuki Y, Okumura F, Matsuda M, Okumura AJ, Hirata N, Narita M, Kohno T, Yokota J, Bohgaki M, Obuse C, Hatakeyama S, Obata T, Noguchi M The serine threonine kinase Akt is a core survival factor that underlies a variety of human diseases. Although regulatory phosphorylation and dephosphorylation have been well documented, the other posttranslational mechanisms that modulate Akt activity remain unclear. We show here that tetratricopeptide repeat domain 3 (TTC3) is an E3 ligase that interacts with Akt. TTC3 contains a canonical RING finger motif, a pair of tetratricopeptide motifs, a putative Akt phosphorylation site, and nuclear localization signals, and is encoded by a gene within the Down syndrome (DS) critical region on chromosome 21. TTC3 is an Akt-specific E3 lig... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164646 Tue, 01 Dec 2009 00:00:00 +0100 3164646 http://www.medworm.com/index.php?rid=3164645&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059951%26dopt%3DAbstract Authors: Ferguson S, Raimondi A, Paradise S, Shen H, Mesaki K, Ferguson A, Destaing O, Ko G, Takasaki J, Cremona O, O' Toole E, De Camilli P The GTPase dynamin, a key player in endocytic membrane fission, interacts with numerous proteins that regulate actin dynamics and generate/sense membrane curvature. To determine the functional relationship between these proteins and dynamin, we have analyzed endocytic intermediates that accumulate in cells that lack dynamin (derived from dynamin 1 and 2 double conditional knockout mice). In these cells, actin-nucleating proteins, actin, and BAR domain proteins accumulate at the base of arrested endocytic clathrin-coated pits, where they support the growth of dynamic long tubular necks. These results, which we show reflect the sequence of events in... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164645 Tue, 01 Dec 2009 00:00:00 +0100 3164645 http://www.medworm.com/index.php?rid=3164644&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059952%26dopt%3DAbstract Authors: Slaughter BD, Das A, Schwartz JW, Rubinstein B, Li R In budding yeast, the highly conserved small GTPase Cdc42 localizes to the cortex at a cell pole and orchestrates the trafficking and deposition of cell surface materials required for building a bud or mating projection (shmoo). Using a combination of quantitative imaging and mathematical modeling, we elucidate mechanisms of dynamic recycling of Cdc42 that balance diffusion. Rdi1, a guanine nucleotide dissociation inhibitor (GDI), mediates a fast recycling pathway, while actin patch-mediated endocytosis accounts for a slower one. These recycling mechanisms are restricted to the same region of the nascent bud, as both are coupled to the Cdc42 GTPase cycle. We find that a single dynamic parameter, the rate of internalization i... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164644 Tue, 01 Dec 2009 00:00:00 +0100 3164644 http://www.medworm.com/index.php?rid=3164643&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059953%26dopt%3DAbstract Authors: Yokoyama S, Ito Y, Ueno-Kudoh H, Shimizu H, Uchibe K, Albini S, Mitsuoka K, Miyaki S, Kiso M, Nagai A, Hikata T, Osada T, Fukuda N, Yamashita S, Harada D, Mezzano V, Kasai M, Puri PL, Hayashizaki Y, Okado H, Hashimoto M, Asahara H We created a whole-mount in situ hybridization (WISH) database, termed EMBRYS, containing expression data of 1520 transcription factors and cofactors expressed in E9.5, E10.5, and E11.5 mouse embryos--a highly dynamic stage of skeletal myogenesis. This approach implicated 43 genes in regulation of embryonic myogenesis, including a transcriptional repressor, the zinc-finger protein RP58 (also known as Zfp238). Knockout and knockdown approaches confirmed an essential role for RP58 in skeletal myogenesis. Cell-based high-throughput transfection screenin... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164643 Tue, 01 Dec 2009 00:00:00 +0100 3164643 http://www.medworm.com/index.php?rid=3164642&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059954%26dopt%3DAbstract Authors: Solar M, Cardalda C, Houbracken I, Martín M, Maestro MA, De Medts N, Xu X, Grau V, Heimberg H, Bouwens L, Ferrer J A longstanding unsettled question is whether pancreatic beta cells originate from exocrine duct cells. We have now used genetic labeling to fate map embryonic and adult pancreatic duct cells. We show that Hnf1beta+ cells of the trunk compartment of the early branching pancreas are precursors of acinar, duct, and endocrine lineages. Hnf1beta+ cells subsequent form the embryonic duct epithelium, which gives rise to both ductal and endocrine lineages, but not to acinar cells. By the end of gestation, the fate of Hnf1beta+ duct cells is further restrained. We provide compelling evidence that the ductal epithelium does not make a significant contribution to acinar... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164642 Tue, 01 Dec 2009 00:00:00 +0100 3164642 http://www.medworm.com/index.php?rid=3164641&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059955%26dopt%3DAbstract This study establishes a mechanistic basis for tendon-skeleton regulatory interactions during musculoskeletal assembly and bone secondary patterning. PMID: 20059955 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164641 Tue, 01 Dec 2009 00:00:00 +0100 3164641 http://www.medworm.com/index.php?rid=3164640&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059956%26dopt%3DAbstract This study reveals a specific class of ILPs induced upon metabolic stress that promotes growth in conditions of nutritional deprivation or following developmentally induced cessation of feeding. PMID: 20059956 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164640 Tue, 01 Dec 2009 00:00:00 +0100 3164640 http://www.medworm.com/index.php?rid=3164639&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059957%26dopt%3DAbstract Authors: Okamoto N, Yamanaka N, Yagi Y, Nishida Y, Kataoka H, O'Connor MB, Mizoguchi A Members of the insulin family of peptides have conserved roles in the regulation of growth and metabolism in a wide variety of metazoans. Here we show that Drosophila insulin-like peptide 6 (DILP6), which is structurally similar to vertebrate insulin-like growth factor (IGF), is predominantly expressed in the fat body, a functional equivalent of the vertebrate liver and adipocytes. This expression occurs during the postfeeding stage under the direct regulation of ecdysteroid. We further reveal that dilp6 mutants show growth defects during the postfeeding stage, which results in reduced adult body size through a decrease in cell number. This phenotype is rescued by fat body-specific expression of dilp... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164639 Tue, 01 Dec 2009 00:00:00 +0100 3164639 http://www.medworm.com/index.php?rid=3164638&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059958%26dopt%3DAbstract Authors: Lagha M, Brunelli S, Messina G, Cumano A, Kume T, Relaix F, Buckingham ME Maintenance of multipotency and how cells exit this state to adopt a specific fate are central questions in stem cell biology. During vertebrate development, multipotent cells of the dorsal somite, the dermomyotome, give rise to different lineages such as vascular smooth and skeletal muscle, regulated by the transcription factors Foxc2 and Pax3, respectively. Here we show reciprocal inhibition between Pax3 and Foxc2 in the mouse embryo. Using both genetic approaches and manipulation of external signals in somite explants, we demonstrate that the Pax3:Foxc2 ratio modulates myogenic versus vascular cell fates. This provides insight into how cell fate choices are orchestrated by these lineage genes in the d... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164638 Tue, 01 Dec 2009 00:00:00 +0100 3164638 http://www.medworm.com/index.php?rid=3164637&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20059959%26dopt%3DAbstract Authors: Kitagawa D, Busso C, Flückiger I, Gönczy P Despite being essential for proper cell division, the mechanisms governing centrosome duplication are incompletely understood and represent an important open question in cell biology. Formation of a new centriole next to each existing one is critical for centrosome duplication. In Caenorhabditis elegans embryos, the proteins SPD-2, ZYG-1, SAS-6, SAS-5, and SAS-4 are essential for centriole formation, but the mechanisms underlying their requirement remain unclear. Here, we demonstrate that the kinase ZYG-1 phosphorylates the coiled-coil protein SAS-6 at serine 123 in vitro. Importantly, we show that this phosphorylation event is crucial for centriole formation in vivo. Furthermore, we establish that such phosphorylation ensur... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3164637 Tue, 01 Dec 2009 00:00:00 +0100 3164637 http://www.medworm.com/index.php?rid=3010108&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922861%26dopt%3DAbstract Authors: Sweet DJ PMID: 19922861 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010108 Tue, 17 Nov 2009 00:00:00 +0100 3010108 http://www.medworm.com/index.php?rid=3010102&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922862%26dopt%3DAbstract Authors: Bear JE Two new studies published in this issue of Developmental Cell by Derivery et al. and Gomez and Billadeau reveal that WASH (Wiskott-Aldrich syndrome protein and SCAR homolog) activates Arp2/3 on endosomes and plays a critical role in the fission of tubules that serve as transport intermediates during endosome sorting. PMID: 19922862 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010102 Tue, 17 Nov 2009 00:00:00 +0100 3010102 http://www.medworm.com/index.php?rid=3010101&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922863%26dopt%3DAbstract Authors: Feinberg T, Weiss SJ In mammals, proteolytic remodeling of the embryonic extracellular matrix (ECM) controls morphogenesis, but the key players remain elusive. Two recent reports identify new roles for metalloproteinases belonging to the MT-MMP and ADAMTS families in branching morphogenesis and interdigital web regression. PMID: 19922863 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010101 Tue, 17 Nov 2009 00:00:00 +0100 3010101 http://www.medworm.com/index.php?rid=3010099&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922864%26dopt%3DAbstract Authors: Burke B, Roux KJ Eukaryotic cells display considerable morphological plasticity linked to their abilities to carry out a myriad of complex functions. Structural rearrangements associated with cellular activities, from yeast mitosis to cell migration in the mammalian central nervous system, often involve relocation of the cell nucleus. Recent studies have provided insight into how nuclear components can be mechanically coupled to the cytoskeleton, providing a more complete understanding of the role of nuclear positioning in both health and disease. PMID: 19922864 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010099 Tue, 17 Nov 2009 00:00:00 +0100 3010099 http://www.medworm.com/index.php?rid=3010098&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922865%26dopt%3DAbstract Authors: Hiraoka Y, Dernburg AF Recent studies in diverse eukaryotes have implicated a family of nuclear envelope proteins containing SUN domains as key components of meiotic nuclear organization and chromosome dynamics. In many cases, these transmembrane proteins are also known to contribute to centrosome or spindle pole body function in mitotically dividing cells. During meiotic prophase, the apparent role of these SUN-domain proteins, together with their partner KASH-domain proteins, is to connect chromosomes through the intact nuclear envelope to force-generating mechanisms in the cytoplasm. PMID: 19922865 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010098 Tue, 17 Nov 2009 00:00:00 +0100 3010098 http://www.medworm.com/index.php?rid=3010097&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922866%26dopt%3DAbstract Authors: Hetzer MW, Wente SR Over the last decade, the nuclear envelope (NE) has emerged as a key component in the organization and function of the nuclear genome. As many as 100 different proteins are thought to specifically localize to this double membrane that separates the cytoplasm and the nucleoplasm of eukaryotic cells. Selective portals through the NE are formed at sites where the inner and outer nuclear membranes are fused, and the coincident assembly of approximately 30 proteins into nuclear pore complexes occurs. These nuclear pore complexes are essential for the control of nucleocytoplasmic exchange. Many of the NE and nuclear pore proteins are thought to play crucial roles in gene regulation and thus are increasingly linked to human diseases. PMID: 19922866 [PubMed - a... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010097 Tue, 17 Nov 2009 00:00:00 +0100 3010097 http://www.medworm.com/index.php?rid=3010096&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922867%26dopt%3DAbstract Authors: Xylourgidis N, Fornerod M Nuclear pore complexes (NPCs) mediate all selective bidirectional transport between the nucleus and the cytoplasm. Additional functions for NPCs and their constituent proteins (nucleoporins) are emerging, some independent of classical transport. Specifically, enzymatic activities at the NPC regulate nucleocytoplasmic transport and use the NPC as a regulatory scaffold. Also, nucleoporins may regulate gene expression by contacting chromatin. Discriminating between effects on transport, scaffolding, and gene expression is a major challenge in understanding the role of the NPC in signaling and development. PMID: 19922867 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010096 Tue, 17 Nov 2009 00:00:00 +0100 3010096 http://www.medworm.com/index.php?rid=3010092&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922868%26dopt%3DAbstract Authors: Dauer WT, Worman HJ The development of a membrane-bound structure separating DNA from other cellular components was the epochal evolutionary event that gave rise to eukaryotes, possibly occurring up to 2 billion years ago. Yet, this view of the nuclear envelope as a physical barrier greatly underestimates its fundamental impact on cellular organization and complexity, much of which is only beginning to be understood. Indeed, alterations of nuclear envelope structure and protein composition are essential to many aspects of metazoan development and cellular differentiation. Mutations in genes encoding nuclear envelope proteins cause a fascinating array of diseases referred to as "nuclear envelopathies" or "laminopathies" that affect different tissues and organ systems. We review... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010092 Tue, 17 Nov 2009 00:00:00 +0100 3010092 http://www.medworm.com/index.php?rid=3010083&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922869%26dopt%3DAbstract Authors: Matera AG, Izaguire-Sierra M, Praveen K, Rajendra TK The principles of self-assembly and self-organization are major tenets of molecular and cellular biology. Governed by these principles, the eukaryotic nucleus is composed of numerous subdomains and compartments, collectively described as nuclear bodies. Emerging evidence reveals that associations within and between various nuclear bodies and genomic loci are dynamic and can change in response to cellular signals. This review will discuss recent progress in our understanding of how nuclear body components come together, what happens when they form, and what benefit these subcellular structures may provide to the tissues or organisms in which they are found. PMID: 19922869 [PubMed - as supplied by publisher] (Source: Devel... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010083 Tue, 17 Nov 2009 00:00:00 +0100 3010083 http://www.medworm.com/index.php?rid=3010082&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922870%26dopt%3DAbstract Authors: Griffin CA, Kafadar KA, Pavlath GK Odorant receptors (ORs) in the olfactory epithelium bind to volatile small molecules leading to the perception of smell. ORs are expressed in many tissues but their functions are largely unknown. We show multiple ORs display distinct mRNA expression patterns during myogenesis in vitro and muscle regeneration in vivo. Mouse OR23 (MOR23) expression is induced during muscle regeneration when muscle cells are extensively fusing and plays a key role in regulating migration and adhesion of muscle cells in vitro, two processes common during tissue repair. A soluble ligand for MOR23 is secreted by muscle cells in vitro and muscle tissue in vivo. MOR23 is necessary for proper skeletal muscle regeneration as loss of MOR23 leads to increased myofiber br... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010082 Tue, 17 Nov 2009 00:00:00 +0100 3010082 http://www.medworm.com/index.php?rid=3010081&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922871%26dopt%3DAbstract Authors: van Rooij E, Quiat D, Johnson BA, Sutherland LB, Qi X, Richardson JA, Kelm RJ, Olson EN Myosin is the primary regulator of muscle strength and contractility. Here we show that three myosin genes, Myh6, Myh7, and Myh7b, encode related intronic microRNAs (miRNAs), which, in turn, control muscle myosin content, myofiber identity, and muscle performance. Within the adult heart, the Myh6 gene, encoding a fast myosin, coexpresses miR-208a, which regulates the expression of two slow myosins and their intronic miRNAs, Myh7/miR-208b and Myh7b/miR-499, respectively. miR-208b and miR-499 play redundant roles in the specification of muscle fiber identity by activating slow and repressing fast myofiber gene programs. The actions of these miRNAs are mediated in part by a collection of trans... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010081 Tue, 17 Nov 2009 00:00:00 +0100 3010081 http://www.medworm.com/index.php?rid=3010080&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922872%26dopt%3DAbstract In conclusion, our data show that Moz regulates H3K9 acetylation at Hox gene loci and that RA can act independently of Moz to establish specific Hox gene expression boundaries. PMID: 19922872 [PubMed - as supplied by publisher] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010080 Tue, 17 Nov 2009 00:00:00 +0100 3010080 http://www.medworm.com/index.php?rid=3010079&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922873%26dopt%3DAbstract Authors: McCulloch DR, Nelson CM, Dixon LJ, Silver DL, Wylie JD, Lindner V, Sasaki T, Cooley MA, Argraves WS, Apte SS We show that combinatorial mouse alleles for the secreted metalloproteases Adamts5, Adamts20 (bt), and Adamts9 result in fully penetrant soft-tissue syndactyly. Interdigital webs in Adamts5(-/-);bt/bt mice had reduced apoptosis and decreased cleavage of the proteoglycan versican; however, the BMP-FGF axis, which regulates interdigital apoptosis was unaffected. BMP4 induced apoptosis, but without concomitant versican proteolysis. Haploinsufficiency of either Vcan or Fbln1, a cofactor for versican processing by ADAMTS5, led to highly penetrant syndactyly in bt mice, suggesting that cleaved versican was essential for web regression. The local application of an aminotermina... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010079 Tue, 17 Nov 2009 00:00:00 +0100 3010079 http://www.medworm.com/index.php?rid=3010078&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922874%26dopt%3DAbstract Authors: Gomez TS, Billadeau DD The Arp2/3 complex regulates endocytosis, sorting, and trafficking, yet the Arp2/3-stimulating factors orchestrating these distinct events remain ill defined. WASH (Wiskott-Aldrich Syndrome Protein and SCAR Homolog) is an Arp2/3 activator with unknown function that was duplicated during primate evolution. We demonstrate that WASH associates with tubulin and localizes to early endosomal subdomains, which are enriched in Arp2/3, F-actin, and retromer components. Although WASH localized with activated receptors, it was not essential for endocytosis. However, WASH did regulate retromer-mediated retrograde CI-MPR trafficking, which required its association with endosomes, Arp2/3-directed F-actin regulation, and tubulin interaction. Moreover, WASH exists in a ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010078 Tue, 17 Nov 2009 00:00:00 +0100 3010078 http://www.medworm.com/index.php?rid=3010076&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922875%26dopt%3DAbstract Authors: Derivery E, Sousa C, Gautier JJ, Lombard B, Loew D, Gautreau A The Arp2/3 complex generates branched actin networks when activated by Nucleation Promoting Factors (NPFs). Recently, the WASH family of NPFs has been identified, but its cellular role is unclear. Here, we show that WASH generates an actin network on a restricted domain of sorting and recycling endosomes. We found that WASH belongs to a multiprotein complex containing seven subunits, including the heterodimer of capping protein (CP). In vitro, the purified WASH complex activates Arp2/3-mediated actin nucleation and binds directly to liposomes. WASH also interacts with dynamin. WASH depletion gives rise to long membrane tubules pulled out from endosomes along microtubules, as does dynamin inhibition. Accordingly, WA... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010076 Tue, 17 Nov 2009 00:00:00 +0100 3010076 http://www.medworm.com/index.php?rid=3010073&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19922876%26dopt%3DAbstract Authors: Kaminsky R, Denison C, Bening-Abu-Shach U, Chisholm AD, Gygi SP, Broday L Sumoylation is a reversible posttranslational modification that plays roles in many processes, including transcriptional regulation, cell division, chromosome integrity, and DNA damage response. Using a proteomics approach, we identified approximately 250 candidate targets of sumoylation in C. elegans. One such target is the cytoplasmic intermediate filament (cIF) protein named IFB-1, which is expressed in hemidesmosome-like structures in the worm epidermis and is essential for embryonic elongation and maintenance of muscle attachment to the cuticle. In the absence of SUMO, IFB-1 formed ectopic filaments and protein aggregates in the lateral epidermis. Moreover, depletion of SUMO or mutation of the SUMO ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=3010073 Tue, 17 Nov 2009 00:00:00 +0100 3010073 http://www.medworm.com/index.php?rid=2955185&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19879198%26dopt%3DAbstract Authors: Fernandez-Gonzalez R, Simoes SD, Röper JC, Eaton S, Zallen JA Axis elongation in Drosophila occurs through polarized cell rearrangements driven by actomyosin contractility. Myosin II promotes neighbor exchange through the contraction of single cell boundaries, while the contraction of myosin II structures spanning multiple pairs of cells leads to rosette formation. Here we show that multicellular actomyosin cables form at a higher frequency than expected by chance, indicating that cable assembly is an active process. Multicellular cables are sites of increased mechanical tension as measured by laser ablation. Fluorescence recovery after photobleaching experiments show that myosin II is stabilized at the cortex in regions of increased tension. Myosin II is recruited in res... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2955185 Wed, 28 Oct 2009 00:00:00 +0100 2955185 http://www.medworm.com/index.php?rid=2928044&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853568%26dopt%3DAbstract Authors: Carroll SY, Stirling PC, Stimpson HE, Gießelmann E, Schmitt MJ, Drubin DG Like Ricin, Shiga, and Cholera toxins, yeast K28 is an A/B toxin that depends on endocytosis and retrograde trafficking for toxicity. Knowledge of the specific proteins, lipids, and mechanisms required for trafficking and killing by these toxins remains incomplete. Since K28 is a model for clinically relevant toxins, we screened over 5000 yeast mutants, identifying 365 that affect K28 sensitivity. Hypersensitive mutants revealed cytoprotective pathways, including stress-activated signaling and protein degradation. Resistant mutants clustered to endocytic, lipid organization, and cell wall biogenesis pathways. Furthermore, GPI anchors and transcriptional regulation are important for K28-cell binding.... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928044 Tue, 20 Oct 2009 00:00:00 +0100 2928044 http://www.medworm.com/index.php?rid=2928057&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853555%26dopt%3DAbstract Authors: Nelson KS, Beitel GJ An unresolved question in vasculogenesis is how mammalian endothelial cells make lumens in developing vessels. In this issue of Developmental Cell, Strilic et al. present a comprehensive analysis of murine arterial lumen formation that defines cellular and molecular events required for lumen morphogenesis and argues against a previous paradigm of lumen formation. PMID: 19853555 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928057 Thu, 01 Oct 2009 00:00:00 +0100 2928057 http://www.medworm.com/index.php?rid=2928056&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853556%26dopt%3DAbstract Authors: Wordeman L, Stumpff J Kinesin-8 family members function in microtubule length control and exhibit highly processive plus-end directed motility in conjunction with microtubule dissassembly activity. In a recent issue of Cell, Varga and colleagues describe how these two activities may be used to simultaneously measure and adjust the length of cellular microtubules. PMID: 19853556 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928056 Thu, 01 Oct 2009 00:00:00 +0100 2928056 http://www.medworm.com/index.php?rid=2928055&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853557%26dopt%3DAbstract Authors: Aulehla A, Pourquie O Hox genes are well known for their evolutionarily conserved role in patterning the body axis. Now, Young et al. in this issue of Developmental Cell present evidence that at least in mouse embryos Hox genes do more, namely controlling the process of axis formation itself. PMID: 19853557 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928055 Thu, 01 Oct 2009 00:00:00 +0100 2928055 http://www.medworm.com/index.php?rid=2928054&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853558%26dopt%3DAbstract Authors: Merdes G, Paro R The identities of cells, determined by differential gene expression, are heritably maintained by the antagonistic functions of Polycomb group (PcG) and Trithorax group proteins. Two recent papers shed new light on tumor suppressive functions of PcG by reporting direct silencing of the Notch and JAK/STAT signaling pathways in Drosophila melanogaster. PMID: 19853558 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928054 Thu, 01 Oct 2009 00:00:00 +0100 2928054 http://www.medworm.com/index.php?rid=2928053&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853559%26dopt%3DAbstract Authors: Kovacs JJ, Hara MR, Davenport CL, Kim J, Lefkowitz RJ Arrestins were identified as mediators of G protein-coupled receptor (GPCR) desensitization and endocytosis. However, it is now clear that they scaffold many intracellular signaling networks to modulate the strength and duration of signaling by diverse types of receptors-including those relevant to the Hedgehog, Wnt, Notch, and TGFbeta pathways-and downstream kinases such as the MAPK and Akt/PI3K cascades. The involvement of arrestins in many discrete developmental signaling events suggests an indispensable role for these multifaceted molecular scaffolds. PMID: 19853559 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928053 Thu, 01 Oct 2009 00:00:00 +0100 2928053 http://www.medworm.com/index.php?rid=2928052&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853560%26dopt%3DAbstract Authors: Brisbin S, Liu J, Boudreau J, Peng J, Evangelista M, Chin-Sang I PTEN is one of the most commonly lost tumor suppressors in human cancer and is known to inhibit insulin signaling. Eph receptor tyrosine kinases (RTKs) have also been implicated in cancer formation and progression, and they have diverse functions, including nervous and vascular system development. We show that in C. elegans, the VAB-1 Eph kinase domain physically interacts with and phosphorylates PTEN (DAF-18), diminishing its protein levels and function. vab-1 mutants show increased longevity and sensitivity to dauer conditions, consistent with increased DAF-18/PTEN activity and decreased insulin-like signaling. Moreover, daf-18 mutations suppress vab-1 oocyte maturation phenotypes independent of PI3K signaling.... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928052 Thu, 01 Oct 2009 00:00:00 +0100 2928052 http://www.medworm.com/index.php?rid=2928051&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853561%26dopt%3DAbstract Authors: Yan D, Wu Y, Feng Y, Lin SC, Lin X Dally-like (Dlp) is a glypican-type heparan sulfate proteoglycan (HSPG), containing a protein core and attached glycosaminoglycan (GAG) chains. In Drosophila wing discs, Dlp represses short-range Wingless (Wg) signaling, but activates long-range Wg signaling. Here, we show that Dlp core protein has similar biphasic activity as wild-type Dlp. Dlp core protein can interact with Wg; the GAG chains enhance this interaction. Importantly, we find that Dlp exhibits a biphasic response, regardless of whether its glycosylphosphatidylinositol linkage to the membrane can be cleaved. Rather, the transition from signaling activator to repressor is determined by the relative expression levels of Dlp and the Wg receptor, Frizzled (Fz) 2. Based on these data... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928051 Thu, 01 Oct 2009 00:00:00 +0100 2928051 http://www.medworm.com/index.php?rid=2928050&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853562%26dopt%3DAbstract Authors: Rebustini IT, Myers C, Lassiter KS, Surmak A, Szabova L, Holmbeck K, Pedchenko V, Hudson BG, Hoffman MP Proteolysis is essential during branching morphogenesis, but the roles of MT-MMPs and their proteolytic products are not clearly understood. Here, we discover that decreasing MT-MMP activity during submandibular gland branching morphogenesis decreases proliferation and increases collagen IV and MT-MMP expression. Specifically, reducing epithelial MT2-MMP profoundly decreases proliferation and morphogenesis, increases Col4a2 and intracellular accumulation of collagen IV, and decreases the proteolytic release of collagen IV NC1 domains. Importantly, we demonstrate the presence of collagen IV NC1 domains in developing tissue. Furthermore, recombinant collagen IV NC1 domains res... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928050 Thu, 01 Oct 2009 00:00:00 +0100 2928050 http://www.medworm.com/index.php?rid=2928049&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853563%26dopt%3DAbstract Authors: Langenhan T, Prömel S, Mestek L, Esmaeili B, Waller-Evans H, Hennig C, Kohara Y, Avery L, Vakonakis I, Schnabel R, Russ AP Understanding the mechanisms that coordinate the orientation of cell division planes during embryogenesis and morphogenesis is a fundamental problem in developmental biology. Here we show that the orphan receptor lat-1, a homolog of vertebrate latrophilins, plays an essential role in the establishment of tissue polarity in the C. elegans embryo. We provide evidence that lat-1 is required for the alignment of cell division planes to the anterior-posterior axis and acts in parallel to known polarity and morphogenesis signals. lat-1 is a member of the Adhesion-GPCR protein family and is structurally related to flamingo/CELSR, an essential component of th... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928049 Thu, 01 Oct 2009 00:00:00 +0100 2928049 http://www.medworm.com/index.php?rid=2928048&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853564%26dopt%3DAbstract Authors: Strilić B, Kucera T, Eglinger J, Hughes MR, McNagny KM, Tsukita S, Dejana E, Ferrara N, Lammert E In vertebrates, endothelial cells (ECs) form blood vessels in every tissue. Here, we investigated vascular lumen formation in the developing aorta, the first and largest arterial blood vessel in all vertebrates. Comprehensive imaging, pharmacological manipulation, and genetic approaches reveal that, in mouse embryos, the aortic lumen develops extracellularly between adjacent ECs. We show that ECs adhere to each other, and that CD34-sialomucins, Moesin, F-actin, and non-muscle Myosin II localize at the endothelial cell-cell contact to define the luminal cell surface. Resultant changes in EC shape lead to lumen formation. Importantly, VE-Cadherin and VEGF-A act at different st... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928048 Thu, 01 Oct 2009 00:00:00 +0100 2928048 http://www.medworm.com/index.php?rid=2928047&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853565%26dopt%3DAbstract Authors: Young T, Rowland JE, van de Ven C, Bialecka M, Novoa A, Carapuco M, van Nes J, de Graaff W, Duluc I, Freund JN, Beck F, Mallo M, Deschamps J Hox and Cdx transcription factors regulate embryonic positional identities. Cdx mutant mice display posterior body truncations of the axial skeleton, neuraxis, and caudal urorectal structures. We show that trunk Hox genes stimulate axial extension, as they can largely rescue these Cdx mutant phenotypes. Conversely, posterior (paralog group 13) Hox genes can prematurely arrest posterior axial growth when precociously expressed. Our data suggest that the transition from trunk to tail Hox gene expression successively regulates the construction and termination of axial structures in the mouse embryo. Thus, Hox genes seem to differentially orc... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928047 Thu, 01 Oct 2009 00:00:00 +0100 2928047 http://www.medworm.com/index.php?rid=2928046&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853566%26dopt%3DAbstract Authors: Maeda T, Ito K, Merghoub T, Poliseno L, Hobbs RM, Wang G, Dong L, Maeda M, Dore LC, Zelent A, Luzzatto L, Teruya-Feldstein J, Weiss MJ, Pandolfi PP GATA-1-dependent transcription is essential for erythroid differentiation and maturation. Suppression of programmed cell death is also thought to be critical for this process; however, the link between these two features of erythropoiesis has remained elusive. Here, we show that the POZ-Krüppel family transcription factor, LRF (also known as Zbtb7a/Pokemon), is a direct target of GATA1 and plays an essential antiapoptotic role during terminal erythroid differentiation. We find that loss of Lrf leads to lethal anemia in embryos, due to increased apoptosis of late-stage erythroblasts. This programmed cell death is Arf and p53 in... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928046 Thu, 01 Oct 2009 00:00:00 +0100 2928046 http://www.medworm.com/index.php?rid=2928045&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853567%26dopt%3DAbstract Authors: Zhang T, Nirantar S, Lim HH, Sinha I, Surana U DNA damage checkpoint prevents segregation of damaged chromosomes by imposing cell-cycle arrest. In budding yeast, Mec1, Chk1, and Rad53 (homologous to human ATM/ATR, Chk1, and Chk2 kinases, respectively) are among the main effectors of this pathway. The DNA damage checkpoint is thought to inhibit chromosome segregation by preventing separase-mediated cleavage of cohesins. Here, we describe a regulatory network that prevents segregation of damaged chromosomes by restricting spindle elongation and acts in parallel with inhibition of cohesin cleavage. This control circuit involves Rad53, polo kinase, the anaphase-promoting complex activator Cdh1, and the bimC kinesin family proteins Cin8 and Kip1. The inhibition of polo kinase by Ra... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928045 Thu, 01 Oct 2009 00:00:00 +0100 2928045 http://www.medworm.com/index.php?rid=2928043&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853569%26dopt%3DAbstract Authors: Choe SK, Lu P, Nakamura M, Lee J, Sagerström CG Hox proteins form complexes with Pbx and Meis cofactors to control gene expression, but the role of Meis is unclear. We demonstrate that Hoxb1-regulated promoters are highly acetylated on histone H4 (AcH4) and occupied by Hoxb1, Pbx, and Meis in zebrafish tissues where these promoters are active. Inhibition of Meis blocks gene expression and reduces AcH4 levels at these promoters, suggesting a role for Meis in maintaining AcH4. Within Hox transcription complexes, Meis binds directly to Pbx and we find that this binding displaces histone deacetylases (HDACs) from Hoxb1-regulated promoters in zebrafish embryos. Accordingly, Pbx mutants that cannot bind Meis act as repressors by recruiting HDACs and reducing AcH4 levels, while ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928043 Thu, 01 Oct 2009 00:00:00 +0100 2928043 http://www.medworm.com/index.php?rid=2928042&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19853570%26dopt%3DAbstract We present new approaches to cis-regulatory module (CRM) discovery in the common scenario where relevant transcription factors and/or motifs are unknown. Beginning with a small list of CRMs mediating a common gene expression pattern, we search genome-wide for CRMs with similar functionality, using new statistical scores and without requiring known motifs or accurate motif discovery. We cross-validate our predictions on 31 regulatory networks in Drosophila and through correlations with gene expression data. Five predicted modules tested using an in vivo reporter gene assay all show tissue-specific regulatory activity. We also demonstrate our methods' ability to predict mammalian tissue-specific enhancers. Finally, we predict human CRMs that regulate early blood and cardiovascular developmen... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2928042 Thu, 01 Oct 2009 00:00:00 +0100 2928042 http://www.medworm.com/index.php?rid=2805247&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758552%26dopt%3DAbstract Authors: Herz HM, Nakanishi S, Shilatifard A Bivalently marked chromatin, containing both histone H3 lysine 4 (H3K4) and H3K27 trimethylation, is a hallmark of developmentally regulated paused promoters in mammalian embryonic stem cells. In this issue of Developmental Cell, Akkers et al. report that Xenopus tropicalis embryos transition through early development without the requirement for bivalently marked promoters. PMID: 19758552 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805247 Mon, 31 Aug 2009 23:00:00 +0100 2805247 http://www.medworm.com/index.php?rid=2805246&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758553%26dopt%3DAbstract Authors: Kateneva AV, Higgins JM Timely release of sister chromatid cohesion is essential for accurate chromosome segregation during cell division. Shugoshin forms a complex with the phosphatase PP2A that has been proposed to dephosphorylate cohesin proteins to prevent premature loss of centromeric cohesion. A recent study in Molecular Cell by Xu et al. presents the structure of Shugoshin bound to PP2A and provides evidence that this interaction is required for cohesion protection. PMID: 19758553 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805246 Mon, 31 Aug 2009 23:00:00 +0100 2805246 http://www.medworm.com/index.php?rid=2805245&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758554%26dopt%3DAbstract Authors: Kalitsis P, Choo KH The conserved centromere protein C (CENP-C) is indispensable for kinetochore function. Yet its mechanism of action has remained elusive. In this issue of Developmental Cell, Tanaka et al. report that the fission yeast homolog, Cnp3, acts as a linker protein that fulfills a variety of different roles in the bi- and mono-orientation of chromosomes during mitosis and meiosis I. PMID: 19758554 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805245 Mon, 31 Aug 2009 23:00:00 +0100 2805245 http://www.medworm.com/index.php?rid=2805244&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758555%26dopt%3DAbstract Authors: Carlson B, Soderling SH F-BAR domains bind curved membranes and induce membrane invagination. In a recent Cell paper, Guerrier et al. describe an "inverse" F-BAR family member that induces outward curvature and filopodia in migrating neurons. These findings suggest that F-BAR domains are functionally diverse and regulate different types of membrane morphology. PMID: 19758555 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805244 Mon, 31 Aug 2009 23:00:00 +0100 2805244 http://www.medworm.com/index.php?rid=2805243&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758556%26dopt%3DAbstract Authors: Insall RH, Machesky LM Cell migration is an essential feature of eukaryotic life, required for processes ranging from feeding and phagoctyosis to development, healing, and immunity. Migration requires the actin cytoskeleton, specifically the localized polymerization of actin filaments underneath the plasma membrane. Here we summarize recent developments in actin biology that particularly affect structures at the leading edge of the cell, including the structure of actin branches, the multiple pathways that lead to cytoskeleton assembly and disassembly, and the role of blebs. Future progress depends on connecting these processes and components to the dynamic behavior of the whole cell in three dimensions. PMID: 19758556 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805243 Mon, 31 Aug 2009 23:00:00 +0100 2805243 http://www.medworm.com/index.php?rid=2805242&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758557%26dopt%3DAbstract Authors: Lomakin AJ, Semenova I, Zaliapin I, Kraikivski P, Nadezhdina E, Slepchenko BM, Akhmanova A, Rodionov V Cytoplasmic microtubules (MTs) continuously grow and shorten at free plus ends. During mitosis, this dynamic behavior allows MTs to capture chromosomes to initiate their movement to the spindle poles; however, the role of MT dynamics in capturing organelles for transport in interphase cells has not been demonstrated. Here we use Xenopus melanophores to test the hypothesis that MT dynamics significantly contribute to the efficiency of MT minus-end directed transport of membrane organelles. We demonstrate that initiation of transport of membrane-bounded melanosomes (pigment granules) to the cell center involves their capture by MT plus ends, and that inhibition of MT dynamics o... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805242 Mon, 31 Aug 2009 23:00:00 +0100 2805242 http://www.medworm.com/index.php?rid=2805241&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758558%26dopt%3DAbstract Authors: Tanaka K, Chang HL, Kagami A, Watanabe Y The conserved kinetochore protein CENP-C plays a fundamental role in chromosome segregation, but its specific functions remain elusive. We have gained insights into the role of CENP-C through identification of interacting effector proteins required for kinetochore function in fission yeast. Fta1/CENP-L is a primary effector that associates directly with Cnp3/CENP-C, and ectopic localization of Fta1 largely suppresses the mitotic kinetochore defects of cnp3Delta cells. Pcs1 functions downstream of Cnp3 to prevent merotelic attachment. In meiosis, Cnp3 further associates with and recruits Moa1, a meiosis-specific protein exclusively required for the mono-orientation of kinetochores. Genetic and biochemical analyses identified Cnp3 mutants... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805241 Mon, 31 Aug 2009 23:00:00 +0100 2805241 http://www.medworm.com/index.php?rid=2805240&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758559%26dopt%3DAbstract Authors: Tsou MF, Wang WJ, George KA, Uryu K, Stearns T, Jallepalli PV It has been proposed that separase-dependent centriole disengagement at anaphase licenses centrosomes for duplication in the next cell cycle. Here we test whether such a mechanism exists in intact human cells. Loss of separase blocked centriole disengagement during mitotic exit and delayed assembly of new centrioles during the following S phase; however, most engagements were eventually dissolved. We identified Polo-like kinase 1 (Plk1) as a parallel activator of centriole disengagement. Timed inhibition of Plk1 mapped its critical period of action to late G2 or early M phase, i.e., prior to securin destruction and separase activation at anaphase onset. Crucially, when cells exited mitosis after downregulation of bo... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805240 Mon, 31 Aug 2009 23:00:00 +0100 2805240 http://www.medworm.com/index.php?rid=2805239&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758560%26dopt%3DAbstract We describe a mechanism that prevents precocious mitosis in germ cells undergoing meiosis, propose that this mechanism maintains germ cell identity by delaying the onset of embryonic gene activation until after fertilization, and provide a paradigm for the possible origin of human teratomas. PMID: 19758560 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805239 Mon, 31 Aug 2009 23:00:00 +0100 2805239 http://www.medworm.com/index.php?rid=2805238&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758561%26dopt%3DAbstract Authors: Tzouanacou E, Wegener A, Wymeersch FJ, Wilson V, Nicolas JF Clonal lineage information is fundamental in revealing cell fate choices. Using genetic single-cell labeling in utero, we investigated lineage segregations during anteroposterior axis formation in mouse. We show that while endoderm and surface ectoderm segregate during gastrulation, neural ectoderm and mesoderm share a common progenitor persisting through all stages of axis elongation. These data challenge the paradigm that the three germ layers, formed by gastrulation, constitute the primary branchpoints in differentiation of the pluripotent epiblast toward tissue-specific precursors. Bipotent neuromesodermal progenitors show self-renewing characteristics and may represent the cellular substrate coupling sustained ax... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805238 Mon, 31 Aug 2009 23:00:00 +0100 2805238 http://www.medworm.com/index.php?rid=2805237&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758562%26dopt%3DAbstract Authors: Chappell JC, Taylor SM, Ferrara N, Bautch VL Blood vessel networks form via sprouting of endothelial cells from parent vessels. Extrinsic cues guide sprouts after they leave the initiation site, but these cues are likely insufficient to regulate initial outward movement, and many embryonic vessel networks form in the absence of a strong extrinsic gradient. We hypothesized that nascent sprouts are guided by spatial cues produced along their own vessels, and that soluble Flt-1 (sFlt-1) participates in this guidance. Analysis of developing vessels with perturbed flt-1 function revealed misguided emerging sprouts, and transgenic sFlt-1 rescued sprout guidance parameters. sflt-1 activity in endothelial cells immediately adjacent to the emerging sprout significantly improved local s... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805237 Mon, 31 Aug 2009 23:00:00 +0100 2805237 http://www.medworm.com/index.php?rid=2805236&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758563%26dopt%3DAbstract Authors: Yan Y, Denef N, Schüpbach T We have identified Rabconnectin-3alpha and beta (Rbcn-3A and B) as two regulators of Notch signaling in Drosophila. We found that, in addition to disrupting Notch signaling, mutations in Rbcn-3A and B cause defects in endocytic trafficking, where Notch and other membrane proteins accumulate in late endosomal compartments. We show that Notch is transported to the surface of mutant cells and that signaling is disrupted after the S2 cleavage. Interestingly, the yeast homolog of Rbcn-3A, Rav1, regulates the V-ATPase proton pump responsible for acidifying intracellular organelles. We found that, similarly, Rbcn-3A and B appear to regulate V-ATPase function. Moreover, we identified mutants in VhaAC39, a V-ATPase subunit, and showed that they phenocop... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805236 Mon, 31 Aug 2009 23:00:00 +0100 2805236 http://www.medworm.com/index.php?rid=2805235&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758564%26dopt%3DAbstract Authors: Zink S, Wenzel D, Wurm CA, Schmitt HD The yeast Dsl1p vesicle tethering complex, comprising the three subunits Dsl1p, Dsl3p, and Tip20p, is stably associated with three endoplasmic reticulum-localized Q-SNAREs and is believed to play a central role in the tethering and fusion of Golgi-derived COP-I transport vesicles. Dsl1p also interacts directly with COP-I subunits. We now show that binding of Dsl1p to COP-I subunits involves binding sites identical to those involved in interactions between COP-I subunits that stabilize the COP-I coat. Cells with defects in Dsl/SNARE complex function show massive accumulation of COP-I-coated vesicles in a cluster to which COP-II coat proteins are also recruited. Our results suggest that binding of Dsl/SNARE complex to the COP-I coat complex ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805235 Mon, 31 Aug 2009 23:00:00 +0100 2805235 http://www.medworm.com/index.php?rid=2805234&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758565%26dopt%3DAbstract Authors: Pek JW, Lim AK, Kai T Nuage is a germline-unique perinuclear structure conserved throughout the animal kingdom. Maelstrom (Mael) is an unusual nuage component, as it is also found in the nucleus. Mael contains a High Mobility Group box, known to mediate DNA binding. We show that Mael nuclear function is required for proper differentiation in the Drosophila germline stem cell (GSC) lineage. In mael mutant testes, transit-amplifying cysts fail to differentiate into primary spermatocytes, instead breaking down into ectopic GSCs and smaller cysts, due to a depletion of Bag-of-marbles (Bam) protein. Mael regulates Bam via repression of miR-7. Mael binds the miR-7 promoter and is required for the local accumulation of HP1 and H3K9me3. miR-7 targets bam directly at its 3'UTR, and a r... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805234 Mon, 31 Aug 2009 23:00:00 +0100 2805234 http://www.medworm.com/index.php?rid=2805233&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19758566%26dopt%3DAbstract Authors: Akkers RC, van Heeringen SJ, Jacobi UG, Janssen-Megens EM, Françoijs KJ, Stunnenberg HG, Veenstra GJ Epigenetic mechanisms set apart the active and inactive regions in the genome of multicellular organisms to produce distinct cell fates during embryogenesis. Here, we report on the epigenetic and transcriptome genome-wide maps of gastrula-stage Xenopus tropicalis embryos using massive parallel sequencing of cDNA (RNA-seq) and DNA obtained by chromatin immunoprecipitation (ChIP-seq) of histone H3 K4 and K27 trimethylation and RNA Polymerase II (RNAPII). These maps identify promoters and transcribed regions. Strikingly, genomic regions featuring opposing histone modifications are mostly transcribed, reflecting spatially regulated expression rather than bivalency as determine... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2805233 Mon, 31 Aug 2009 23:00:00 +0100 2805233 http://www.medworm.com/index.php?rid=2713519&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686672%26dopt%3DAbstract Authors: Braun T, Dimmeler S Several recent findings challenge our view of the heart as a postmitotic organ and suggest that the adult heart has some capacity to regenerate. Bersell et al. in a recent issue of Cell report that neuregulin1-mediated activation of ErbB2/4 receptors induces proliferation of adult mononuclear cardiomyocytes. PMID: 19686672 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713519 Fri, 31 Jul 2009 23:00:00 +0100 2713519 http://www.medworm.com/index.php?rid=2713518&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686673%26dopt%3DAbstract Authors: Krahn MP, Wodarz A Activation of Notch by its transmembrane ligand Delta requires the E3 ubiquitin ligases Neuralized or Mind bomb and endocytosis of the ubiquitinated ligand. In this issue of Developmental Cell, Ossipova et al. show that the polarity regulator PAR-1 phosphorylates Mind bomb, leading to the degradation of Mind bomb and to changes in cell fate due to loss of Notch signaling. PMID: 19686673 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713518 Fri, 31 Jul 2009 23:00:00 +0100 2713518 http://www.medworm.com/index.php?rid=2713517&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686674%26dopt%3DAbstract Authors: Kroos L Bacteria communicate via extracellular signals. Most signaling studied so far has been bidirectional. A recent study shows that when Bacillus subtilis build a multicellular biofilm, some conversations are unidirectional. PMID: 19686674 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713517 Fri, 31 Jul 2009 23:00:00 +0100 2713517 http://www.medworm.com/index.php?rid=2713516&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686675%26dopt%3DAbstract Authors: Barlowe C The endoplasmic reticulum (ER) adopts a remarkable array of flattened membrane structures and branched tubular networks to support cellular function. Recent studies reveal that the integral membrane atlastin GTPases, which are linked to neurodegenerative diseases, catalyze membrane fusion and are required for the formation of branched membrane networks characteristic of the ER. PMID: 19686675 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713516 Fri, 31 Jul 2009 23:00:00 +0100 2713516 http://www.medworm.com/index.php?rid=2713515&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686676%26dopt%3DAbstract Authors: Wickström SA, Fässler R Cell invasion through the basement membrane, a process important for both development and disease pathogenesis, depends on an interplay of adhesive, force transducing, proteolytic, and chemotactic machineries. The mechanisms whereby these different processes are integrated on the cellular level have remained elusive. In this issue of Developmental Cell, Sherwood and coworkers now identify integrins as integration platforms for a specialized invasive membrane domain in C. elegans. PMID: 19686676 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713515 Fri, 31 Jul 2009 23:00:00 +0100 2713515 http://www.medworm.com/index.php?rid=2713514&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686677%26dopt%3DAbstract Authors: Matzuk MM The transcription factor BLIMP1 is a master regulator of primordial germ cell (PGC) specification and is suppressed by the microRNA let-7. In a recent issue of Nature, West and colleagues use a unique in vitro ES cell differentiation strategy to show that LIN28 is an essential regulator of PGC formation through inhibition of let-7 maturation and consequential induction of BLIMP1. PMID: 19686677 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713514 Fri, 31 Jul 2009 23:00:00 +0100 2713514 http://www.medworm.com/index.php?rid=2713513&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686678%26dopt%3DAbstract Authors: Martindale MQ, Hejnol A Progress in resolving the phylogenetic relationships among animals and the expansion of molecular developmental studies to a broader variety of organisms has provided important insights into the evolution of developmental programs. These new studies make it possible to reevaluate old hypotheses about the evolution of animal body plans and to elaborate new ones. Here, we review recent studies that shed light on the transition from a radially organized ancestor to the last common ancestor of the Bilateria ("Urbilaterian") and present an integrative hypothesis about plausible developmental scenarios for the evolution of complex multicellular animals. PMID: 19686678 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713513 Fri, 31 Jul 2009 23:00:00 +0100 2713513 http://www.medworm.com/index.php?rid=2713512&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686679%26dopt%3DAbstract Authors: Bazigou E, Xie S, Chen C, Weston A, Miura N, Sorokin L, Adams R, Muro AF, Sheppard D, Makinen T Dysfunction of lymphatic valves underlies human lymphedema, yet the process of valve morphogenesis is poorly understood. Here, we show that during embryogenesis, lymphatic valve leaflet formation is initiated by upregulation of integrin-alpha9 expression and deposition of its ligand fibronectin-EIIIA (FN-EIIIA) in the extracellular matrix. Endothelial cell-specific deletion of Itga9 (encoding integrin-alpha9) in mouse embryos results in the development of rudimentary valve leaflets characterized by disorganized FN matrix, short cusps, and retrograde lymphatic flow. Similar morphological and functional defects are observed in mice lacking the EIIIA domain of FN. Mechanistically, we d... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713512 Fri, 31 Jul 2009 23:00:00 +0100 2713512 http://www.medworm.com/index.php?rid=2713511&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686680%26dopt%3DAbstract Authors: Hagedorn EJ, Yashiro H, Ziel JW, Ihara S, Wang Z, Sherwood DR Integrin expression and activity have been strongly correlated with developmental and pathological processes involving cell invasion through basement membranes. The role of integrins in mediating these invasions, however, remains unclear. Utilizing the genetically and visually accessible model of anchor cell (AC) invasion in C. elegans, we have recently shown that netrin signaling orients a specialized invasive cell membrane domain toward the basement membrane. Here, we demonstrate that the integrin heterodimer INA-1/PAT-3 plays a crucial role in AC invasion, in part by targeting the netrin receptor UNC-40 (DCC) to the AC's plasma membrane. Analyses of the invasive membrane components phosphatidylinositol 4,5-bispho... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713511 Fri, 31 Jul 2009 23:00:00 +0100 2713511 http://www.medworm.com/index.php?rid=2713510&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686681%26dopt%3DAbstract Authors: Chi X, Michos O, Shakya R, Riccio P, Enomoto H, Licht JD, Asai N, Takahashi M, Ohgami N, Kato M, Mendelsohn C, Costantini F While the genetic control of renal branching morphogenesis has been extensively described, the cellular basis of this process remains obscure. GDNF/RET signaling is required for ureter and kidney development, and cells lacking Ret are excluded from the tips of the branching ureteric bud in chimeric kidneys. Here, we find that this exclusion results from earlier Ret-dependent cell rearrangements in the caudal Wolffian duct, which generate a specialized epithelial domain that later emerges as the tip of the primary ureteric bud. By juxtaposing cells with elevated or reduced RET activity, we find that Wolffian duct cells compete, based on RET signaling level... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713510 Fri, 31 Jul 2009 23:00:00 +0100 2713510 http://www.medworm.com/index.php?rid=2713509&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686682%26dopt%3DAbstract Authors: Zhao X, D' Arca D, Lim WK, Brahmachary M, Carro MS, Ludwig T, Cardo CC, Guillemot F, Aldape K, Califano A, Iavarone A, Lasorella A Self-renewal and proliferation of neural stem cells and the decision to initiate neurogenesis are crucial events directing brain development. Here we show that the ubiquitin ligase Huwe1 operates upstream of the N-Myc-DLL3-Notch pathway to control neural stem cell activity and promote neurogenesis. Conditional inactivation of the Huwe1 gene in the mouse brain caused neonatal lethality associated with disorganization of the laminar patterning of the cortex. These defects stemmed from severe impairment of neurogenesis associated with uncontrolled expansion of the neural stem cell compartment. Loss- and gain-of-function experiments in the mouse cortex... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713509 Fri, 31 Jul 2009 23:00:00 +0100 2713509 http://www.medworm.com/index.php?rid=2713508&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686683%26dopt%3DAbstract Authors: Ossipova O, Ezan J, Sokol SY Generation of neurons in the vertebrate central nervous system requires a complex transcriptional regulatory network and signaling processes in polarized neuroepithelial progenitor cells. Here we demonstrate that neurogenesis in the Xenopus neural plate in vivo and mammalian neural progenitors in vitro involves intrinsic antagonistic activities of the polarity proteins PAR-1 and aPKC. Furthermore, we show that Mind bomb (Mib), a ubiquitin ligase that promotes Notch ligand trafficking and activity, is a crucial molecular substrate for PAR-1. The phosphorylation of Mib by PAR-1 results in Mib degradation, repression of Notch signaling, and stimulation of neuronal differentiation. These observations suggest a conserved mechanism for neuronal fate dete... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713508 Fri, 31 Jul 2009 23:00:00 +0100 2713508 http://www.medworm.com/index.php?rid=2713507&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686684%26dopt%3DAbstract Authors: Im YJ, Wollert T, Boura E, Hurley JH The ESCRT-II-ESCRT-III interaction coordinates the sorting of ubiquitinated cargo with the budding and scission of intralumenal vesicles into multivesicular bodies. The interacting regions of these complexes were mapped to the second winged helix domain of human ESCRT-II subunit VPS25 and the first helix of ESCRT-III subunit VPS20. The crystal structure of this complex was determined at 2.0 A resolution. Residues involved in structural interactions explain the specificity of ESCRT-II for Vps20, and are critical for cargo sorting in vivo. ESCRT-II directly activates ESCRT-III-driven vesicle budding and scission in vitro via these structural interactions. VPS20 and ESCRT-II bind membranes with nanomolar affinity, explaining why binding to ESC... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713507 Fri, 31 Jul 2009 23:00:00 +0100 2713507 http://www.medworm.com/index.php?rid=2713506&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686685%26dopt%3DAbstract Authors: Khmelinskii A, Roostalu J, Roque H, Antony C, Schiebel E The metaphase-to-anaphase transition is one of the most dramatic and highly regulated steps in cell division. At anaphase onset the protease separase dissolves sister chromatid cohesion. Simultaneously, the mitotic spindle elongates as interpolar microtubules (iMTs) slide apart at the spindle midzone, ensuring chromosome segregation. However, it remains unclear how spindle elongation is coordinated with cell cycle progression. Here we demonstrate that phosphorylation of the midzone organizer Ase1 controls localization and function of Cin8, a kinesin-5 that slides iMTs relative to each other. Phosphorylation of Ase1 by Cdk1 (cyclin-dependent kinase) inhibits Cin8 binding to iMTs, preventing bending and collapse of the met... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713506 Fri, 31 Jul 2009 23:00:00 +0100 2713506 http://www.medworm.com/index.php?rid=2713505&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686686%26dopt%3DAbstract Authors: Fu C, Ward JJ, Loiodice I, Velve-Casquillas G, Nedelec FJ, Tran PT The spindle midzone-composed of antiparallel microtubules, microtubule-associated proteins (MAPs), and motors-is the structure responsible for microtubule organization and sliding during anaphase B. In general, MAPs and motors stabilize the midzone and motors produce sliding. We show that fission yeast kinesin-6 motor klp9p binds to the microtubule antiparallel bundler ase1p at the midzone at anaphase B onset. This interaction depends upon the phosphorylation states of klp9p and ase1p. The cyclin-dependent kinase cdc2p phosphorylates and its antagonist phosphatase clp1p dephosphorylates klp9p and ase1p to control the position and timing of klp9p-ase1p interaction. Failure of klp9p-ase1p binding leads to decreas... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713505 Fri, 31 Jul 2009 23:00:00 +0100 2713505 http://www.medworm.com/index.php?rid=2713504&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686687%26dopt%3DAbstract Authors: Yamaguchi A, Wu MF, Yang L, Wu G, Poethig RS, Wagner D When to form flowers is a developmental decision that profoundly impacts the fitness of flowering plants. In Arabidopsis this decision is ultimately controlled by the induction and subsequent activity of the transcription factors LEAFY (LFY), FRUITFULL (FUL), and APETALA1 (AP1). Despite their central importance, our current understanding of the regulation of LFY, FUL, and AP1 expression is still incomplete. We show here that all three genes are directly activated by the microRNA-targeted transcription factor SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 3 (SPL3). Our findings suggest that SPL3 acts together with other microRNA-regulated SPL transcription factors to control the timing of flower formation. Moreover, the identified ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713504 Fri, 31 Jul 2009 23:00:00 +0100 2713504 http://www.medworm.com/index.php?rid=2713503&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686688%26dopt%3DAbstract Authors: Chera S, Ghila L, Dobretz K, Wenger Y, Bauer C, Buzgariu W, Martinou JC, Galliot B Decapitated Hydra regenerate their heads via morphallaxis, i.e., without significant contributions made by cell proliferation or interstitial stem cells. Indeed, Hydra depleted of interstitial stem cells regenerate robustly, and Wnt3 from epithelial cells triggers head regeneration. However, we find a different mechanism controlling regeneration after midgastric bisection in animals equipped with both epithelial and interstitial cell lineages. In this context, we see rapid induction of apoptosis and Wnt3 secretion among interstitial cells at the head- (but not foot-) regenerating site. Apoptosis is both necessary and sufficient to induce Wnt3 production and head regeneration, even at ectopic sit... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713503 Fri, 31 Jul 2009 23:00:00 +0100 2713503 http://www.medworm.com/index.php?rid=2713502&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19686689%26dopt%3DAbstract Authors: Goss AM, Tian Y, Tsukiyama T, Cohen ED, Zhou D, Lu MM, Yamaguchi TP, Morrisey EE Patterning of the primitive foregut promotes appropriate organ specification along its anterior-posterior axis. However, the molecular pathways specifying foregut endoderm progenitors are poorly understood. We show here that Wnt2/2b signaling is required to specify lung endoderm progenitors within the anterior foregut. Embryos lacking Wnt2/2b expression exhibit complete lung agenesis and do not express Nkx2.1, the earliest marker of the lung endoderm. In contrast, other foregut endoderm-derived organs, including the thyroid, liver, and pancreas, are correctly specified. The phenotype observed is recapitulated by an endoderm-restricted deletion of beta-catenin, demonstrating that Wnt2/2b signaling ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2713502 Fri, 31 Jul 2009 23:00:00 +0100 2713502 http://www.medworm.com/index.php?rid=2630519&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619484%26dopt%3DAbstract Authors: Ishihara N, Mizushima N Mitochondria play central roles in cell survival by producing energy, and in cell death by regulating apoptosis. Conversely, the life and death of mitochondria, including growth, fission, and autophagic degradation, is controlled by the host cell. Using yeast genetics, a mitochondrial surface receptor involved in mitochondrial autophagy has recently been identified. PMID: 19619484 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630519 Tue, 30 Jun 2009 23:00:00 +0100 2630519 http://www.medworm.com/index.php?rid=2630518&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619485%26dopt%3DAbstract Authors: Almeida R, Tyers M The phenomenon of cell size homeostasis, whereby cells coordinate growth and division to maintain a uniform cell size, has been an outstanding issue in cell biology for many decades. Two recent studies in Nature in fission yeast demonstrate that a gradient of the polarity factor Pom1 is a sensor of cell length that determines the onset of Cdc2 activation and mitosis. PMID: 19619485 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630518 Tue, 30 Jun 2009 23:00:00 +0100 2630518 http://www.medworm.com/index.php?rid=2630517&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619486%26dopt%3DAbstract Authors: Johnson SL Many of our ideas about cellular memory of fate and position come from regeneration studies in salamanders. A popular notion is that cells of the blastema transdifferentiate to different fates during limb regeneration. In a recent issue of Nature, Tanaka and colleagues challenge this notion. Using transplant experiments with GFP-expressing axolotl, they show vividly which cells of the blastema remember their fate and position of origin. PMID: 19619486 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630517 Tue, 30 Jun 2009 23:00:00 +0100 2630517 http://www.medworm.com/index.php?rid=2630516&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619487%26dopt%3DAbstract Authors: Goraksha-Hicks P, Rathmell JC Nutrient overabundance is known to promote cellular hypertrophy, a significant pathological event in diseases like diabetes and cancer, although mechanisms have remained unclear. In this issue of Developmental Cell, Wu and Derynck provide a new model that links metabolism and cell growth by demonstrating that hyperglycemia can increase TGF-beta-dependent activation of the mTOR pathway to promote cellular hyperplasia. PMID: 19619487 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630516 Tue, 30 Jun 2009 23:00:00 +0100 2630516 http://www.medworm.com/index.php?rid=2630515&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619488%26dopt%3DAbstract Authors: MacDonald BT, Tamai K, He X Signaling by the Wnt family of secreted glycolipoproteins via the transcriptional coactivator beta-catenin controls embryonic development and adult homeostasis. Here we review recent progress in this so-called canonical Wnt signaling pathway. We discuss Wnt ligands, agonists, and antagonists, and their interactions with Wnt receptors. We also dissect critical events that regulate beta-catenin stability, from Wnt receptors to the cytoplasmic beta-catenin destruction complex, and nuclear machinery that mediates beta-catenin-dependent transcription. Finally, we highlight some key aspects of Wnt/beta-catenin signaling in human diseases including congenital malformations, cancer, and osteoporosis, and discuss potential therapeutic implications. PMID:... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630515 Tue, 30 Jun 2009 23:00:00 +0100 2630515 http://www.medworm.com/index.php?rid=2630514&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619489%26dopt%3DAbstract Authors: Phillips BT, Kimble J The canonical Wnt/beta-catenin pathway is extensively characterized, broadly conserved, and clinically important. In this review, we describe the C. elegans Wnt/beta-catenin asymmetry pathway and suggest that some of its unusual features may have important implications for the canonical Wnt/beta-catenin pathway. PMID: 19619489 [PubMed - in process] (Source: Developmental Cell) Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630514 Tue, 30 Jun 2009 23:00:00 +0100 2630514 http://www.medworm.com/index.php?rid=2630513&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619490%26dopt%3DAbstract Authors: Wu L, Derynck R In multicellular organisms, cell size is tightly controlled by nutrients and growth factors. Increasing ambient glucose induces enhanced protein synthesis and cell size. Continued exposure of cells to high glucose in vivo, as apparent under pathological conditions, results in cell hypertrophy and tissue damage. We demonstrate that activation of TGF-beta signaling has a central role in glucose-induced cell hypertrophy in fibroblasts and epithelial cells. Blocking the kinase activity of the TbetaRI receptor or loss of its expression prevented the effects of high glucose on protein synthesis and cell size. Exposure of cells to high glucose induced a rapid increase in cell surface levels of the TbetaRI and TbetaRII receptors and a rapid activation of TGF-beta ligan... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630513 Tue, 30 Jun 2009 23:00:00 +0100 2630513 http://www.medworm.com/index.php?rid=2630512&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619491%26dopt%3DAbstract Authors: Zhang Y, Tomann P, Andl T, Gallant NM, Huelsken J, Jerchow B, Birchmeier W, Paus R, Piccolo S, Mikkola ML, Morrisey EE, Overbeek PA, Scheidereit C, Millar SE, Schmidt-Ullrich R Wnt/beta-catenin and NF-kappaB signaling mechanisms provide central controls in development and disease, but how these pathways intersect is unclear. Using hair follicle induction as a model system, we show that patterning of dermal Wnt/beta-catenin signaling requires epithelial beta-catenin activity. We find that Wnt/beta-catenin signaling is absolutely required for NF-kappaB activation, and that Edar is a direct Wnt target gene. Wnt/beta-catenin signaling is initially activated independently of EDA/EDAR/NF-kappaB activity in primary hair follicle primordia. However, Eda/Edar/NF-kappaB signaling is req... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630512 Tue, 30 Jun 2009 23:00:00 +0100 2630512 http://www.medworm.com/index.php?rid=2630511&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619492%26dopt%3DAbstract Authors: Spence JR, Lange AW, Lin SC, Kaestner KH, Lowy AM, Kim I, Whitsett JA, Wells JM The ventral pancreas, biliary system, and liver arise from the posterior ventral foregut, but the cell-intrinsic pathway by which these organ lineages are separated is not known. Here we show that the extrahepatobiliary system shares a common origin with the ventral pancreas and not the liver, as previously thought. These pancreatobiliary progenitor cells coexpress the transcription factors PDX1 and SOX17 at E8.5 and their segregation into a PDX1+ ventral pancreas and a SOX17+ biliary primordium is Sox17-dependent. Deletion of Sox17 at E8.5 results in the loss of biliary structures and ectopic pancreatic tissue in the liver bud and common duct, while Sox17 overexpression suppresses pancreas develop... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630511 Tue, 30 Jun 2009 23:00:00 +0100 2630511 http://www.medworm.com/index.php?rid=2630510&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619493%26dopt%3DAbstract Authors: Fornara F, Panigrahi KC, Gissot L, Sauerbrunn N, Rühl M, Jarillo JA, Coupland G Flowering of Arabidopsis is induced by long summer days (LDs). The transcriptional regulator CONSTANS (CO) promotes flowering, and its transcription is increased under LDs. We systematically misexpressed transcription factors in companion cells and identified several DOF proteins that delay flowering by repressing CO transcription. Combining mutations in four of these, including CYCLING DOF FACTOR 2 (CDF2), caused photoperiod-insensitive early flowering by increasing CO mRNA levels. CO transcription is promoted to differing extents by GIGANTEA (GI) and the F-box protein FKF1. We show that GI stabilizes FKF1, thereby reducing CDF2 abundance and allowing transcription of CO. Despite the crucial ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630510 Tue, 30 Jun 2009 23:00:00 +0100 2630510 http://www.medworm.com/index.php?rid=2630509&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619494%26dopt%3DAbstract Authors: Okamoto K, Kondo-Okamoto N, Ohsumi Y Mitochondria are essential organelles that produce most of the energy for a cell, but concomitantly accumulate oxidative damage. Degradation of damaged mitochondria is critical for cell homeostasis, and this process is thought to be mediated by mitophagy, an autophagy-related pathway specific for mitochondria. However, whether mitochondria are selectively degraded, and how the autophagic machinery is targeted to mitochondria, remain largely unknown. Here we demonstrate that, in post-log phase cells under respiratory conditions, a substantial fraction of mitochondria are exclusively sequestered as cargoes and transported to the vacuole, a lytic compartment in yeast, in an autophagy-dependent manner. Interestingly, we found Atg32, a mitochond... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630509 Tue, 30 Jun 2009 23:00:00 +0100 2630509 http://www.medworm.com/index.php?rid=2630508&cid=s_35511_171_f&fid=35511&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19619495%26dopt%3DAbstract Authors: Kanki T, Wang K, Cao Y, Baba M, Klionsky DJ Mitochondrial quality control is important in maintaining proper cellular homeostasis. Although selective mitochondrial degradation by autophagy (mitophagy) is suggested to have an important role in quality control, and though there is evidence for a direct relation between mitophagy and neurodegenerative diseases, the molecular mechanism of mitophagy is poorly understood. Using a screen for mitophagy-deficient mutants, we found that YIL146C/ECM37 is essential for mitophagy. This gene is not required for other types of selective autophagy or for nonspecific macroautophagy. We designated this autophagy-related (ATG) gene as ATG32. The Atg32 protein localizes on mitochondria. Following the induction of mitophagy, Atg32 binds Atg11, an ... Developmental Cell journals http://www.medworm.com/rss/comments.php?id=2630508 Tue, 30 Jun 2009 23:00:00 +0100 2630508