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 'Yeast' source. Mon, 06 Feb 2012 16:52:19 +0100 http://www.medworm.com/index.php?rid=5593066&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.2892 ABSTRACTIn this work, a previously developed minibioreactorwas used to identify an informative stimulus response experiment. The identified stimulus response experiment was a modest 50% shift up in glucose uptake rate (qGLC) that unexpectedly, resulted in a disproportionate transient metabolic response. The 50% shift up in qGLC, in the Biocurve resulted in a near tripling of the online measured oxygen uptake (qO2) and carbon dioxide production (qCO2) rates suggesting a considerable mobilization of glycogen and trehalose. The 50% shift up in qGLC was subsequently studied in detail in a conventional bioreactor (4 L working volume) which confirmed the results obtained with the Biocurve. Especially relevant is the observation that the 50% increase in glucose uptake rate led to a 3‐fold inc... Yeast journals http://www.medworm.com/rss/comments.php?id=5593066 Sun, 01 Jan 2012 05:00:00 +0100 5593066 http://www.medworm.com/index.php?rid=5568859&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.2891 AbstractNew double‐ and triple‐hybrid Saccharomyces yeasts were characterized using PCR‐restriction fragment length polymorphism of 35 nuclear genes, located on different chromosome arms, and the sequencing of one nuclear and one mitochondrial gene. Most of these new hybrids were originally isolated from fermentations; however, two of them correspond to clinical and dietary supplement isolates. This is the first time that the presence of double‐hybrid S. cerevisiae × S. kudriavzevii in non‐fermentative substrates has been reported and investigated. Phylogenetic analysis of the MET6 nuclear gene confirmed the double or triple parental origin of the new hybrids. Restriction analysis of gene regions in these hybrids revealed a high diversity of genome types. From these molecula... Yeast journals http://www.medworm.com/rss/comments.php?id=5568859 Thu, 01 Dec 2011 05:00:00 +0100 5568859 http://www.medworm.com/index.php?rid=5483103&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.2891 AbstractNew double and triple hybrid Saccharomyces yeasts were characterized by using PCR‐restriction fragment length polymorphism of 35 nuclear genes, located at different chromosome arms, and the sequencing of one nuclear and one mitochondrial genes. Most of these new hybrids were originally isolated from fermentations, however, two of them correspond to clinical and dietary supplement isolates. This is the first time that the presence of double hybrids S. cerevisiae x S. kudriavzevii in non‐fermentative substrates is reported and investigated.The phylogenetic analysis of the MET6 nuclear gene confirmed the double or triple parental origin of the new hybrids. The restriction analysis of gene regions in these hybrids revealed a high diversity of genome types. From these molecular char... Yeast journals http://www.medworm.com/rss/comments.php?id=5483103 Thu, 01 Dec 2011 05:00:00 +0100 5483103 http://www.medworm.com/index.php?rid=5447631&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1916 AbstractThe Saccharomyces cerevisiae RSC (remodel the structure of chromatin) complex is involved in functions associated with the transcriptional regulation, cell cycle progression, DNA damage repair and cell wall integrity. Here we investigate the cellular functioning of HTL1, which encodes a non‐essential subunit of the RSC complex. The results show that the ∆htl1 mutant displays a characteristic defect in cell wall integrity, and the phenotype of the ∆htl1 cells, which include the cell wall defect, temperature sensitivity and ploidy increase, are rescued by the osmotic stabilizer sorbitol but not by overexpression of PKC1, the signalling kinase important for the cell wall biogenesis and stress response. In addition, the expression level of Slt2p, the MAP kinase downstream of the ... Yeast journals http://www.medworm.com/rss/comments.php?id=5447631 Thu, 24 Nov 2011 05:00:00 +0100 5447631 http://www.medworm.com/index.php?rid=5483104&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1919 (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=5483104 Tue, 15 Nov 2011 05:00:00 +0100 5483104 http://www.medworm.com/index.php?rid=5417637&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1918 ABSTRACTExtraction of high molecular weight chromosomal DNA from yeast cells is a procedure that is performed frequently for experiments involving polymerase chain reaction (PCR), Southern blotting and other DNA analysis techniques. We have investigated several parameters affecting DNA yield and quality using a simple chemical‐based purification procedure that was modeled on alkaline lysis methods developed for bacterial cells. The three major steps of the procedure, cell lysis, protein removal, and DNA precipitation, were optimized by testing the impacts of several chemicals, including sodium dodecyl sulfate (SDS), sodium hydroxide, Tris buffer, sodium acetate and potassium acetate. Other parameters, such as the effect of elevated temperatures on cell lysis, were also investigated. A ra... Yeast journals http://www.medworm.com/rss/comments.php?id=5417637 Tue, 15 Nov 2011 05:00:00 +0100 5417637 http://www.medworm.com/index.php?rid=5428041&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1917 ABSTRACTOleaginous yeast Yarrowia lipolytica is an important host for the production of lipid‐derived compounds or heterologous proteins. Selection of strong promoters and effective expression systems is critical for heterologous protein secretion. To search for a strong promoter in Y. lipolytica, activities of FBA1, TDH1, and GPM1 promoters were compared to that of TEF1 promoter by constructing GUS reporter fusions. The FBA1 promoter activity was 2.2 and 5.5 times stronger than the TDH1 and GPM1 promoters, respectively. The FBA1IN promoter (FBA1 sequence of −826 to +169) containing an intron (+64 to +165) showed five‐fold higher expression than the FBA1 promoter (−831 to −1). The transcriptional enhancement by the 5’‐region within the FBA1 gene was confirmed by GPM1::FBA1 ch... Yeast journals http://www.medworm.com/rss/comments.php?id=5428041 Tue, 01 Nov 2011 04:00:00 +0100 5428041 http://www.medworm.com/index.php?rid=5417636&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1919 (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=5417636 Tue, 01 Nov 2011 04:00:00 +0100 5417636 http://www.medworm.com/index.php?rid=5447630&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1915 AbstractSaccharomyces cerevisiaeacquires its resistance to carboxylate weak organic acids by inducing a plasma membrane ABC transporter, Pdr12. These acids activate a Zn(II)2Cys6 zinc‐finger transcription factor, War1, which in turn induces thePDR12gene. Mutation of the four potential sites of serine/threonine phosphorylation within the War1 activation domain revealed that Pdr12 induction was lost with mutations S923A or S930A, but not with the corresponding phosphomimetic mutations S923D or S930D. However, phosphorylation at these two sites has not been detected by mass spectrometry, so it still remains uncertain whether these are true sites of phosphorylation or merely serines whose side‐chain hydroxyls are necessary for the proper structuring of the War1 activation domain. Mutation ... Yeast journals http://www.medworm.com/rss/comments.php?id=5447630 Tue, 25 Oct 2011 04:00:00 +0100 5447630 http://www.medworm.com/index.php?rid=5355396&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1913 ABSTRACTThe GDI1 protein related vesicle transport system was studied to investigate the possibility that an exclusion of toxic Zinc (Zn) from the cytoplasm ameliorates Zn toxicity in Saccharomyces cerevisiae (yeast). A temperature‐sensitive gdi1 (originally called sec19) mutant, in which the GDP dissociation inhibitor becomes inactive at the non‐permissive temperature (37 °C), was more sensitive to Zn than its parental GDI1 strain at 32 °C (a moderately non‐permissive temperature). The relative efflux of cytoplasmic Zn in the gdi1 mutant was lower than that in the control strain. Treatment with a vesicle transport specific inhibitor, Brefeldin A, caused an increase of Zn sensitivity and a decrease of Zn efflux in these strains. It is therefore suggested that the GDI1‐related... Yeast journals http://www.medworm.com/rss/comments.php?id=5355396 Tue, 25 Oct 2011 04:00:00 +0100 5355396 http://www.medworm.com/index.php?rid=5355395&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1914 ABSTRACTDiacylglycerol (DAG) acyltransferase catalyzes the final and committed step of triacylglycerol biosynthesis. Eukaryotes commonly contain up to three distinct classes of DAG acyltransferases: acyl‐CoA:diacylglycerol acyltransferase 1 (DGAT1), acyl‐CoA:diacylglycerol acyltransferase 2 (DGAT2), and phospholipid:diacylglycerol acyltransferase (PDAT). The non‐conventional oleaginous yeast, Yarrowia lipolytica, contains at least one homolog of each class and serves as a good model to understand the role of different DAG acyltransferases in the biosynthesis of oil, a critical cellular component that serves as storage molecule as well as buffer for free fatty acids. We used gene disruptions in Y. lipolytica and in vitro enzyme assays to confirm the identity of genes encoding all thre... Yeast journals http://www.medworm.com/rss/comments.php?id=5355395 Tue, 25 Oct 2011 04:00:00 +0100 5355395 http://www.medworm.com/index.php?rid=5396821&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1910 AbstractIn recent years a number of molecular tools have been reported for use in the human fungal pathogen Candida albicans, including PCR‐mediated approaches for gene disruption, conditional expression and epitope tagging. Traditionally these methods have utilized auxotrophic markers; however, the availability of auxotrophic markers can be limiting and in some instances their use may also impact on the interpretation of results. As a result, the use of positive selection markers has now become more commonplace. Here we report the development and validation of a set of cassettes for PCR‐mediated gene tagging and overexpression studies utilizing the nourseothricin resistance (CaNAT1) positive selection marker. In particular we have produced cassettes containing yeast‐enhanced GFP, YF... Yeast journals http://www.medworm.com/rss/comments.php?id=5396821 Thu, 13 Oct 2011 04:00:00 +0100 5396821 http://www.medworm.com/index.php?rid=5396822&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1909 AbstractThe exosome is an evolutionarily conserved 10‐mer complex involved in RNA metabolism, located in both the nucleus and the cytoplasm. The cytoplasmic exosome plays an important role in mRNA turnover through its 3′→5′ exonucleolytic activity. The superkiller (SKI) phenotype of yeast was originally identified as an increase of killer toxin production due to elevated levels of the L‐A double‐stranded RNA (dsRNA) Totivirus and its satellite toxin‐encoding M dsRNA. Most SKI genes were later shown to be either components of the exosome or modulators of its activity. Variations in the amount of Totivirus are, thus, good indicators of yeast exosome activity, and can be used to analyse its components. Furthermore, if exosome proteins of higher eukaryotes were functional in S. c... Yeast journals http://www.medworm.com/rss/comments.php?id=5396822 Tue, 04 Oct 2011 04:00:00 +0100 5396822 http://www.medworm.com/index.php?rid=5281478&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1908 ABSTRACTThe S. cerevisiae Fps1 glycerol channel is a member of the major intrinsic protein (MIP) family of plasma membrane channel proteins that functions in osmoregulatory pathways to transport glycerol passively out of the cell. The MIP family is subdivided into members that are selectively permeable to water (aquaporins), and those permeated by glycerol (aquaglyceroporins or glycerol facilitators). Although aquaporins function as homo‐tetramers with each monomer possessing its own channel, previous studies have suggested that aquaglyceroporins may function as monomers. Here we provide both genetic and biochemical evidence that Fps1 functions as a homotetramer to regulate glycerol transport in yeast. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=5281478 Mon, 03 Oct 2011 04:00:00 +0100 5281478 http://www.medworm.com/index.php?rid=5355394&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1915 ABSTRACTSaccharomyces cerevisiae acquires its resistance to carboxylate weak organic acids by inducing a plasma membrane ABC transporter, Pdr12. These acids activate a Zn(II)2Cys6 zinc‐finger transcription factor, War1, which in turn induces the PDR12 gene. Mutation of the four potential sites of serine/threonine phosphorylation within the War1 activation domain revealed that Pdr12 induction was lost with mutations S923A or S930A, but not with the corresponding phosphomimetic mutations S923D or S930D. However phosphorylation at these two sites has not been detected by mass spectrometry, so it still remains uncertain whether these are true sites of phosphorylation or merely serines whose side chain hydroxyls are necessary for the proper structuring of the War1 activation domain. Mutation ... Yeast journals http://www.medworm.com/rss/comments.php?id=5355394 Sat, 01 Oct 2011 04:00:00 +0100 5355394 http://www.medworm.com/index.php?rid=5343512&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1912 ABSTRACTIn the present study, we functionally analyzed two yapsin genes of the thermotolerant methylotrophic yeast Hansenula polymorpha, HpYPS1 and HpYPS7 for their roles in maintaining cell wall integrity and proteolytic processing. Both HpYPS1 and HpYPS7 proteins were shown to largely localize on the cell wall via glycosylphosphatidylinositol anchor. Heterologous expression of HpYPS1 completely restored all of the growth defects of the Saccharomyces cerevisiae yps1‐deletion strains, while HpYPS7 expression exhibited a limited complementation effect on the S. cerevisiae yps7‐deletion strain. However, different from S. cerevisiae, the deletion of the HpYPS genes generated only minor influence on the sensitivity to cell wall stress. Likewise, HpYPS1 expression was significantly induced ... Yeast journals http://www.medworm.com/rss/comments.php?id=5343512 Sat, 01 Oct 2011 04:00:00 +0100 5343512 http://www.medworm.com/index.php?rid=5330652&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1911 ABSTRACTSeptins are evolutionary conserved proteins that contain a GTPase domain and are capable of forming filaments at the cell periphery. Septins are involved in many essential cellular processes, such as cytokinesis and cell polarization, and are used as markers of morphogenesis in several fungi. Dimorphism in fungi enables cells to switch between morphologies (yeast or filament forms) due to changes in the temperature of the environment. We analyzed the localization of septin proteins in yeast and filamentous cells of the dimorphic fungus Paracoccidioides brasiliensis, a common cause of granulomatous mycosis. In order to determine septin localization, we first cloned Cdc12p, a septin homologue from P. brasiliensis, and expressed it in E. coli. Following PbCdc12p purification, specific... Yeast journals http://www.medworm.com/rss/comments.php?id=5330652 Sat, 01 Oct 2011 04:00:00 +0100 5330652 http://www.medworm.com/index.php?rid=5321518&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1910 AbstractIn recent years a number of molecular tools have been reported for use in the human fungal pathogen Candida albicans, including PCR‐mediated approaches for gene disruption, conditional expression and epitope tagging. Traditionally these methods have utilised auxotrophic markers, however the availability of auxotrophic markers can be limiting and in some instances their use may also impact on the interpretation of results. As a result the use of positive selection markers has now become more commonplace. Here we report the development and validation of a set of cassettes for PCR‐mediated gene tagging and over‐expression studies utilising the nourseothricin resistance (CaNAT1) positive selection marker. In particular we have produced cassettes containing yeast enhanced GFP, YFP... Yeast journals http://www.medworm.com/rss/comments.php?id=5321518 Sat, 01 Oct 2011 04:00:00 +0100 5321518 http://www.medworm.com/index.php?rid=5321519&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1904 AbstractUbiquitin conjugating enzyme 1 (Ubc1) is a member of the E2 family of enzymes that conjugates ubiquitin to damaged proteins destined for degradation by the ubiquitin proteasomal system. It is necessary for stress tolerance and is essential for cell survival in Saccharomyces cerevisiae. Ubc1 has five serine residues that are potential substrates for phosphorylation by kinases. However, no data are available to indicate that Ubc1 function or stress tolerance in S. cerevisiae is regulated by serine phosphorylation of Ubc1. We demonstrate that Ubc1 is phosphorylated in serine residue(s). Furthermore, expression of Ubc1 mutants that are 'constitutively phosphorylated' or 'dephosphorylated' in mitogen‐activated protein (MAP) kinase serine residues (S97 and S115) affected tolerance to t... Yeast journals http://www.medworm.com/rss/comments.php?id=5321519 Thu, 01 Sep 2011 04:00:00 +0100 5321519 http://www.medworm.com/index.php?rid=5310753&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1906 AbstractTy3 elements of S. cerevisiae contain two overlapping coding regions, GAG3 and POL3, which are functional homologues of retroviral gag and pol genes, respectively. Pol3 is translated as a Gag3‐Pol3 fusion protein dependent on a +1 programmed frameshift at a site with the overlap between the two genes. We show that the Ty3 frameshift frequency varies up to 10‐fold in S. cerevisiae cells depending on carbon source. Frameshift efficiency is significantly lower in cells growing on glucose as carbon source than in cells growing on poor alternative carbon sources (glycerol/lactate or galactose). Our results indicate that Ty3 programmed ribosomal frameshift efficiency in response to glucose signalling requires two protein kinases: Snf1p and cAMP‐dependent protein kinase A (PKA). Inc... Yeast journals http://www.medworm.com/rss/comments.php?id=5310753 Thu, 01 Sep 2011 04:00:00 +0100 5310753 http://www.medworm.com/index.php?rid=5281477&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1909 AbstractThe exosome is an evolutionary conserved 10‐mer complex involved in RNA metabolism, located both in the nucleus and in the cytoplasm. The cytoplasmic exosome plays an important role in mRNA turnover through its 3′ → 5′ exonucleolytic activity. The superkiller (SKI) phenotype of yeast was originally identified as an increase of killer toxin production due to elevated levels of the L‐A double‐stranded RNA (dsRNA) Totivirus and its satellite toxin‐encoding M dsRNA. Most SKI genes were later on shown to be either components of the exosome or modulators of its activity. Variations in the amount of Totivirus are, thus, good indicators of yeast exosome activity, and can be used to analyze its components. Furthermore, if exosome proteins of higher eukaryotes were function... Yeast journals http://www.medworm.com/rss/comments.php?id=5281477 Thu, 01 Sep 2011 04:00:00 +0100 5281477 http://www.medworm.com/index.php?rid=5204180&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1907 ABSTRACTAir–liquid biofilm formation appears to be an adaptive mechanism that promotes foraging of Saccharomyces cerevisiae flor strains in response to nutrient starvation. The FLO11 gene plays a central role in this phenotype as its expression allows yeast cells to rise to the liquid surface. Here, we investigated the role of ammonium depletion in air–liquid biofilm formation and FLO11 expression in a S. cerevisiae flor strain. The data obtained show that increasing ammonium concentrations from 0 to 450 mM reduces air–liquid biofilm in terms of biomass and velum formation and correlates with a reduction of FLO11 expression. Rapamycin inhibition of TOR pathway and deletion of RAS2 gene significantly reduced biofilm formation and FLO11 expression. Taken together, these data suggest ... Yeast journals http://www.medworm.com/rss/comments.php?id=5204180 Thu, 01 Sep 2011 04:00:00 +0100 5204180 http://www.medworm.com/index.php?rid=5191185&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1904 AbstractUbiquitin conjugating enzyme 1 (Ubc1) is a member of the E2 family of enzymes that conjugates Ubiquitin to damaged proteins destined for degradation by the Ubiquitin Proteasomal System. It is necessary for stress tolerance and is essential for cell survival in Saccharomyces cerevisiae. Ubc1 has five serine residues that are potential substrates for phosphorylation by kinases. However, no data is available to indicate that Ubc1 function or stress tolerance in S. cerevisiae is regulated by serine‐phosphorylation of Ubc1. We demonstrate that Ubc1 is phosphorylated in serine residue/s. Furthermore, expression of Ubc1 mutants that are “constitutively phosphorylated” or “dephosphorylated” in MAP kinase serine residues (S97 and S115) affected tolerance to thermal and reductive s... Yeast journals http://www.medworm.com/rss/comments.php?id=5191185 Wed, 31 Aug 2011 23:00:00 +0100 5191185 http://www.medworm.com/index.php?rid=5191184&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1905 ABSTRACTA new method for protein extraction from yeast Saccharomyces cerevisiae cells was described. This method involves the use of LiAc and NaOH to enhance the permeability of yeast cell wall prior to protein extraction with SDS‐PAGE sample buffer. It was safe and efficient compared to other methods reported so far in literature. The proteins extracted with this new method retained their immunoreactive properties and suitable for most applications in molecular biology studies. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=5191184 Wed, 31 Aug 2011 23:00:00 +0100 5191184 http://www.medworm.com/index.php?rid=5191183&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1906 ABSTRACTTy3 elements of S. cerevisiae contain two overlapping coding regions, GAG3 and POL3 which are functional homologues of retroviral gag and pol genes, respectively. Pol3 is translated as a Gag3‐Pol3 fusion protein dependent on a +1 programmed frameshift at a site with the overlap between the two genes. We show that the Ty3 frameshift frequency varies up to 10‐fold in S. cerevisiae cells depending on carbon source. Frameshift efficiency is significantly lower on cells growing on glucose as carbon source than on cells growing on poor alternative carbon sources (glycerol/lactate or galactose). Our results indicate that Ty3 programmed ribosomal frameshift efficiency in response to glucose signaling requires two protein kinases: Snf1p and cAMP‐dependent protein kinase A (PKA). Incre... Yeast journals http://www.medworm.com/rss/comments.php?id=5191183 Wed, 31 Aug 2011 23:00:00 +0100 5191183 http://www.medworm.com/index.php?rid=5155628&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1901 SUMMARYYarrowia lipolytica 3589, a tropical marine yeast, grew aerobically on a broad range of bromoalkanes varying in carbon chain length and differing in degree and position of bromide group. Amongst the bromoalkanes studied viz., 2‐bromopropane (2‐BP), 1‐bromobutane (1‐BB), 1, 5‐dibromopentane (DBP) and 1‐ bromodecane (1‐BD) , the best utilized was 1‐BD with a maximal growth rate (μmax) of 0.055h‐1 and an affinity ratio ((μmax/Ks) of 0.022. Utilization of these bromoalkanes as growth substrates was associated with a concomitant release of bromide (8202.9 μM) and cell mass (36 x 109 cells/ml), occurring maximally on 1‐BD. Adherence of yeast cells to these hydrophobic bromoalkanes was observed microscopically with an increase in cell size and surface hydrophobicity.... Yeast journals http://www.medworm.com/rss/comments.php?id=5155628 Wed, 17 Aug 2011 23:00:00 +0100 5155628 http://www.medworm.com/index.php?rid=5155627&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1902 This study focuses on gene expression during crucial biological phenomena of the dimorphic fungal human pathogen Paracoccidioides brasiliensis, the conidia‐to‐yeast (C‐Y) transition and the conidia‐to‐mycelia (C‐M) germination. We studied 10 genes involved in different cellular functions: oxidative stress response [alternative oxidase (AOX), superoxide dismutase (SOD), flavodoxin, conserved hypothetical protein (Y20)]; cell metabolism [glyceraldehyde‐3‐phosphate dehydrogenase (GADPH), cholestenol Delta‐isomerase (ChDI), glycine dehydrogenase (GDh)] and heat shock response [Heat shock protein 90 (HSP90)], and cell synthesis and wall structure [glucan synthase‐1 (GS‐1), α‐1,3‐glucan synthase (αGS), and mannosyltransferase (MT)]. Gene expression was measured during... Yeast journals http://www.medworm.com/rss/comments.php?id=5155627 Wed, 17 Aug 2011 23:00:00 +0100 5155627 http://www.medworm.com/index.php?rid=5204181&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1900 In conclusion, the yeast protein microarray represents a novel crossover technique for identifying unique potential Pc kinase substrates. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=5204181 Wed, 17 Aug 2011 04:00:00 +0100 5204181 http://www.medworm.com/index.php?rid=5155629&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1900 In conclusion, the yeast protein microarray represents a novel cross over technique for identifying unique potential Pc kinase substrates. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=5155629 Tue, 16 Aug 2011 23:00:00 +0100 5155629 http://www.medworm.com/index.php?rid=5155626&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1903 SUMMARYIt has been previously reported that growth of Debaryomyces hansenii in 2 M NaCl induced the expression of ARO4 (Calderón‐Torres et al., 2006). This gene codifies for DhAro4p, involved in the synthesis of the amino acid tyrosine. In this work we studied the activity of DhAro4p upon salt stress; a higher activity was observed in cells grown with 2 M NaCl, but tyrosine levels were not increased. On the other hand, the addition of tyrosine to the saline medium significantly enhanced the growth of D. hansenii. It was found that the oxidized form of tyrosine, 3‐nitro‐tyrosine, increased in presence of salt. Since NaCl protects against oxidative stress in D. hansenii (Navarrete et al., 2009), we propose that a protective pathway is the novo synthesis of tyrosine and its immediate o... Yeast journals http://www.medworm.com/rss/comments.php?id=5155626 Sun, 31 Jul 2011 23:00:00 +0100 5155626 http://www.medworm.com/index.php?rid=5076378&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1897 AbstractDespite the crucial roles of flavin cofactors in metabolism, we know little about the enzymes responsible for turnover of FMN and FAD and their subcellular localization. The mechanism by which mitochondria obtain their own flavin cofactors is an interesting point of investigation because FMN and FAD are mainly located in mitochondria, where they act as redox cofactors of a number of dehydrogenases and oxidases that play a crucial function in both bioenergetics and cellular regulation.In this context, yeast mitochondria capability to metabolise externally added and endogenous FAD and FMN was investigated and use was made of purified and bioenergetically active mitochondria prepared starting from Saccharomyces cerevisiae cell.To determine whether flavin metabolism can occur, the amou... Yeast journals http://www.medworm.com/rss/comments.php?id=5076378 Thu, 28 Jul 2011 23:00:00 +0100 5076378 http://www.medworm.com/index.php?rid=5076377&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1898 ABSTRACTThe construction of diploid cells eases genetic analysis in haploid genetic systems because diploid cells allow for the characterization of essential genes. Here, we report the construction of diploid cells using ade6 point mutants that suppress each other via interallelic complementation in the fission yeast Schizosaccharomyces japonicus var japonicus (Sz. japonicus). We constructed an ade6‐domK mutant in addition to the previously described ade6‐domE. Phenotypes of both mutants exhibited adenine auxotrophy and red colonies. The mutations complemented the phenotypes in a mutually dependent manner. Diploid zygotes, in which the two mutations were introduced simultaneously into the same cells, were isolated by selecting for adenine independence. Such diploid cells are apparently... Yeast journals http://www.medworm.com/rss/comments.php?id=5076377 Thu, 28 Jul 2011 23:00:00 +0100 5076377 http://www.medworm.com/index.php?rid=5017818&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1895 AbstractThe yeast,Saccharomyces cerevisiae, has proven to be an excellent model organism to study the function of proteins. One of the many advantages of yeast is the many genetic tools available to manipulate gene expression, but there are still limitations. To complement the many methods used to control gene expression in yeast, we have established a conditional gene deletion system by using FLP/FRT system on yeast vectors to conditionally delete specific yeast genes. Expression of Flp recombinase, which was under the control of GAL1 promoter, was induced by galactose, which in turn excised FRT sites flanked genes. The efficacy of this system was examined using the following FRT sites flanked genes, HSP104, URA3, and GFP. The pre‐excision frequency of this system, which might be caused... Yeast journals http://www.medworm.com/rss/comments.php?id=5017818 Wed, 06 Jul 2011 23:00:00 +0100 5017818 http://www.medworm.com/index.php?rid=5076376&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1899 We present several lines of evidence that perturbation of DIS3 affects microtubule (MT) localization and structure in Saccharomyces cerevisiae. Cells with a DIS3 mutant: (i) accumulate anaphase and pre‐anaphase mitotic spindles; (ii) exhibit spindles that are mis‐oriented and displaced from the bud neck; (iii) harbor elongated spindle‐associated astral MTs; (iv) have an increased G1 astral MT length and number; and (v) are hypersensitive to MT poisons. Mutations in the core exosome genes RRP4 and MTR3 and the exosome cofactor gene MTR4 – but not other exosome subunit gene mutants – also elicit MT phenotypes. RNA deep sequencing analysis (RNA‐seq) shows broad changes in the levels of cell cycle‐ and MT‐related transcripts in mutant strains. Collectively, the data presented i... Yeast journals http://www.medworm.com/rss/comments.php?id=5076376 Thu, 30 Jun 2011 23:00:00 +0100 5076376 http://www.medworm.com/index.php?rid=5017817&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1896 In this study, the combinatorial patterns of histone modifications were studied by using Bayesian network at the level of individual nucleosomes in S. cerevisiae. Our results indicated that there were 23 combinatorial patterns for 12 histone modifications investigated when general Bayesian network was constructed. Meanwhile, different networks were also constructed for the genes with high transcript levels (H‐network) and low transcript levels (L‐network), respectively. Comparison among the general network, H‐network and L‐network illustrated 4 conserved combinations: H2BK16Ac→H3K4me3, H3K14Ac→H3K4me3, H2AK7Ac→H3K14Ac and H4K12Ac→H3K18Ac. The detailed analysis for some combinations demonstrated that the combinations were ascribed to some histone‐modifying enzymes. Copyri... Yeast journals http://www.medworm.com/rss/comments.php?id=5017817 Thu, 30 Jun 2011 23:00:00 +0100 5017817 http://www.medworm.com/index.php?rid=5085256&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1894 AbstractA consortium of yeast geneticists have created ∼6000 individual ORF deletions, representing > 96% of the currently verified or predicted ORFs in S. cerevisiae. Importantly, molecular barcodes (each a unique 20 bp sequence termed either Uptag or Downtag) were used as identifiers for every ORF deletion. Microarray analyses of pooled yeast deletions has been used to identify thousands of genes involved in general fitness, haploinsufficiency, drug resistance and DNA damage repair. However, application of this powerful technology requires considerable expense, expertise and specialized equipment. While standard PCR techniques and specifically designed PCR primers can be used to confirm that a given ORF is in fact deleted, this procedure cannot be used to identify unknown deletions.... Yeast journals http://www.medworm.com/rss/comments.php?id=5085256 Wed, 22 Jun 2011 23:00:00 +0100 5085256 http://www.medworm.com/index.php?rid=5106094&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1892 AbstractThe pathogenic yeast Candida albicans possesses a reductive iron uptake system which is active in iron‐restricted conditions. The sequestration of iron by this mechanism initially requires the reduction of free iron to the soluble ferrous form, which is catalysed by ferric reductase proteins. Reduced iron is then taken up into the cell by a complex of a multicopper oxidase protein and an iron transport protein. Multicopper oxidase proteins require copper to function and so reductive iron and copper uptake are inextricably linked. It has previously been established that Fre10 is the major cell surface ferric reductase in C. albicans and that transcription of FRE10 is regulated in response to iron levels. We demonstrate here that Fre10 is also a cupric reductase and that Fre7 also ... Yeast journals http://www.medworm.com/rss/comments.php?id=5106094 Mon, 20 Jun 2011 23:00:00 +0100 5106094 http://www.medworm.com/index.php?rid=4951345&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1892 AbstractThe pathogenic yeast Candida albicans possesses a reductive iron uptake system which is active in iron restricted conditions. The sequestration of iron by this mechanism initially requires the reduction of free iron to the soluble ferrous form which is catalysed by ferric reductase proteins. Reduced iron is then taken up into the cell by a complex of a multicopper oxidase protein and an iron transport protein. Multicopper oxidase proteins require copper to function and so reductive iron and copper uptake are inextricably linked.It has previously been established that Fre10 is the major cell surface ferric reductase in C. albicans and that transcription of FRE10 is regulated in response to iron levels. We demonstrate here that Fre10 is also a cupric reductase and that Fre7 also make... Yeast journals http://www.medworm.com/rss/comments.php?id=4951345 Mon, 20 Jun 2011 23:00:00 +0100 4951345 http://www.medworm.com/index.php?rid=5017819&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1891 AbstractThe synthesis of the UV Absorbing compounds named mycosporines (MYCs) has been detected in a few basidiomycetous yeast groups. Conspicuous accumulation of mycosporine‐glutaminol‐glucoside (MGG) in yeasts requires photo‐induction and its photoprotective function has been postulated. The distribution of the ability to produce MYCs appeared to be related to the yeast taxonomic affiliation. In view of the potential significance of MYCs in yeast taxonomy, we here studied the distribution of this trait among dimorphic basidiomycetes of the Pucciniomycotina. Of the 94 fungal species (377 strains and 33 genera) tested, almost half were MYC‐positive and MGG was the main compound produced. MGG synthesis was observed for representatives of five of seven Pucciniomycotina classes, indic... Yeast journals http://www.medworm.com/rss/comments.php?id=5017819 Sat, 11 Jun 2011 23:00:00 +0100 5017819 http://www.medworm.com/index.php?rid=4932266&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1890 Conclusions: CNEO showed strong antifungal effect against all the Candida isolates. Mechanisms of action appear to originate from inhibition of ergosterol biosynthesis and disruption of membrane integrity. It can be concluded that the observed antimicrobial characteristics of C. nepalensis indicate that it might be a promising antimicrobial agent. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=4932266 Sat, 11 Jun 2011 23:00:00 +0100 4932266 http://www.medworm.com/index.php?rid=4959268&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1894 AbstractA consortium of yeast geneticists have created 6,000 individual ORF deletions representing >96% of the currently verified or predicted ORFs in S. cerevisiae. Importantly, molecular barcodes (each a unique 20 bp sequence termed either Uptag or Downtag) were used as identifiers for every ORF deletion. Microarray analyses of pooled yeast deletions has been used to identify thousands of genes involved in general fitness, haploinsufficiency, drug resistance, and DNA damage repair. However, application of this powerful technology requires considerable expense, expertise, and specialized equipment. While standard PCR techniques and specifically designed PCR primers can be used to confirm that a given ORF is in fact deleted, this procedure cannot be used to identify unknown deletions. I... Yeast journals http://www.medworm.com/rss/comments.php?id=4959268 Tue, 31 May 2011 23:00:00 +0100 4959268 http://www.medworm.com/index.php?rid=4951344&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1893 In this study, we investigated the possible reasons for this imbalance by deleting genes required for NADPH production and gluconeogenesis in S. cerevisiae. S. cerevisiae cells expressing the XR/XDH, but not a xylose isomerase, pathway required the oxidative branch of the pentose phosphate pathway (PPP) and gluconeogenic production of glucose‐6‐P for xylose assimilation. The requirement for generating glucose‐6‐P from xylose was also shown for Kluyveromyces lactis. When grown in xylose medium, both K. lactis and S. stipitis showed increases in enzyme activity required for producing glucose‐6‐P. Thus, natural xylose‐assimilating yeast respond to xylose, in part, by upregulating enzymes required for recycling xylose back to glucose‐6‐P for the production of NADPH via the ox... Yeast journals http://www.medworm.com/rss/comments.php?id=4951344 Tue, 31 May 2011 23:00:00 +0100 4951344 http://www.medworm.com/index.php?rid=4932265&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1891 AbstractThe synthesis of the UV‐absorbing compounds named mycosporines (MYC) has been detected in a few Basidiomycetous yeast groups. Conspicuous accumulation of Mycosporine‐glutaminol‐glucoside (MGG) in yeasts requires photo‐induction and its photo‐protective function has been postulated. The distribution of the ability to produce MYC appeared to be related to the yeast taxonomic affiliation. In view of the potential significance of MYC in yeast taxonomy, here, we studied the distribution of this trait among dimorphic basidiomycetes of the Pucciniomycotina. Of the 94 fungal species (377 strains and 33 genera) tested, almost half were MYC positive and MGG was the main compound produced. MGG synthesis was observed for representatives of five of seven Pucciniomycotina classes, indi... Yeast journals http://www.medworm.com/rss/comments.php?id=4932265 Tue, 31 May 2011 23:00:00 +0100 4932265 http://www.medworm.com/index.php?rid=4910380&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1889 In this study, the role of oxidative stress and antioxidant enzymes in the sensitivity of the yeast Saccharomyces cerevisiae to hypochlorite and chlorite was studied. Yeast mutants lacking CuZn‐superoxide dismutase but not mutants deficient in cytoplasmic and peroxisomal catalase were hypersensitive to the action of both hypochlorite and chlorite. Both compounds depleted cellular glutathione, induced the production of reactive oxygen species and decreased the viability of the cells. Toxicity of hypochlorite and chlorite was abolished by hypoxic and anoxic conditions, and ameliorated by thiol antioxidants and ascorbate. The results demonstrate that the action of hypochlorite and chlorite involves formation of superoxide and peroxide, and that SOD1 is protective, probably by limiting forma... Yeast journals http://www.medworm.com/rss/comments.php?id=4910380 Tue, 31 May 2011 23:00:00 +0100 4910380 http://www.medworm.com/index.php?rid=4891580&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1888 AbstractAgt1 is an interesting α‐glucoside transporter for the brewing industry as it efficiently transports maltotriose, a sugar often remaining partly unused during beer fermentation. It has been shown that on maltose the expression level of AGT1 is much higher in ale strains than in lager strains, and that glucose represses the expression particularly in the ale strains. In the present study the regulatory elements of the AGT1 promoter of one ale and two lager strains were identified by computational methods. Promoter regions up to 1.9 kbp upstream of the AGT1 gene were sequenced from the three brewer's yeast strains and the laboratory yeast strain CEN.PK‐1D. The promoter sequence of the laboratory strain was identical to the AGT1 promoter of S288c strain of Saccharomyces Genome Da... Yeast journals http://www.medworm.com/rss/comments.php?id=4891580 Tue, 31 May 2011 23:00:00 +0100 4891580 http://www.medworm.com/index.php?rid=4932267&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1860 AbstractThe ability of Candida albicans to form drug‐resistant biofilms is an important factor in its contribution to human disease. Assays to identify and characterize molecules with activity against fungal biofilms are crucial for the development of drugs with improved anti‐biofilm activity. Here we report the application of an adenylate kinase (AK)‐based cytotoxicity assay of fungal cell lysis to the characterization of agents active against C. albicans biofilms. We have developed three protocols for the AK assay. The first measures AK activity in the supernatants of biofilms treated with antifungal drugs and can be performed in parallel with a standard 2,3‐bis‐(2‐methoxy‐4‐nitro‐5‐sulphophenyl)‐2H‐tetrazolium‐5‐caboxanilide‐based biofilm susceptibility ass... Yeast journals http://www.medworm.com/rss/comments.php?id=4932267 Sun, 15 May 2011 23:00:00 +0100 4932267 http://www.medworm.com/index.php?rid=4870690&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1861 AbstractThe control of transcription factor function plays an important role in the development of many processes in eukaryotes, such as drug resistance in fungi and human tumours undergoing chemotherapy. Detailed molecular mapping of the interactions between transcription factors and their protein partners can give important information about their mechanisms of action and reveal potential therapeutic targets. We devised a genetic screening system for mapping the interaction site between the Saccharomyces cerevisiae transcription factor‐inhibitor pair Gal4p and Gal80p. A novel Gal4p activation domain mutant, L868K, was produced, which prevented it interacting with Gal80p. The split‐ubiquitin system was used with a mutant GAL80 library in order to screen for compensatory mutants in Gal... Yeast journals http://www.medworm.com/rss/comments.php?id=4870690 Sat, 30 Apr 2011 23:00:00 +0100 4870690 http://www.medworm.com/index.php?rid=4839685&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1860 AbstractThe ability of Candidaalbicans to form drug‐resistant biofilms is an important factor in its contribution to human disease. Assays to identify and characterize molecules with activity against fungal biofilms are crucial for the development of drugs with improved anti‐biofilm activity. Here we report the application of an adenylate kinase (AK)‐based cytotoxicity assay of fungal cell lysis to the characterization of agents active against C. albicans biofilms. We have developed three protocols for the AK assay. The first measures AK activity in the supernatants of biofilms treated with antifungal drugs and can be performed in parallel with a standard 2,3‐bis‐(2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐2H‐tetrazolium‐5‐caboxanilide‐based biofilm susceptibility assay... Yeast journals http://www.medworm.com/rss/comments.php?id=4839685 Sat, 30 Apr 2011 23:00:00 +0100 4839685 http://www.medworm.com/index.php?rid=4767505&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1858 AbstractThe ability of a recently isolated Scheffersomycesstipitis strain (UFMG‐IMH 43.2) to produce ethanol from xylose was evaluated. For the assays, a hemicellulosic hydrolysate produced by dilute acid hydrolysis of sugarcane bagasse was used as fermentation medium. Initially, the necessity of adding nutrients (MgSO4× 7H2O, yeast extract and/or urea) to this medium was verified, and the yeast extract supplementation favored the ethanol production by the yeast. Then, in a second stage, assays under different initial xylose and cell concentrations, supplemented or not with yeast extract were performed. All these three variables showed significant (p<0.05) influence on ethanol production. The best results (ethanol yield and productivity of 0.19 g/g and 0.13 g/l.h, respectively) were ... Yeast journals http://www.medworm.com/rss/comments.php?id=4767505 Sat, 30 Apr 2011 11:12:30 +0100 4767505 http://www.medworm.com/index.php?rid=4882730&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1858 AbstractThe ability of a recently isolated Scheffersomyces stipitis strain (UFMG‐IMH 43.2) to produce ethanol from xylose was evaluated. For the assays, a hemicellulosic hydrolysate produced by dilute acid hydrolysis of sugarcane bagasse was used as the fermentation medium. Initially, the necessity of adding nutrients (MgSO4·7H2O, yeast extract and/or urea) to this medium was verified, and the yeast extract supplementation favoured ethanol production by the yeast. Then, in a second stage, assays under different initial xylose and cell concentrations, supplemented or not with yeast extract, were performed. All these three variables showed significant (p < 0.05) influence on ethanol production. The best results (ethanol yield and productivity of 0.19 g/g and 0.13 g/l/h, respectively) w... Yeast journals http://www.medworm.com/rss/comments.php?id=4882730 Thu, 28 Apr 2011 23:00:00 +0100 4882730 http://www.medworm.com/index.php?rid=4747183&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1857 AbstractMost scoring assays for yeast prions are dependent on specific genetic markers and constructs that differ for each prion. Here, we describe a simple color assay for the [URE3] prion that works in the 74D‐964 strain frequently used to score the [PSI+] prion. Although this assay can only be used to score for [URE3] in the [psi‐] version of the strain, it makes it easier to examine the effects of host mutations or environmental changes on [URE3] or [PSI+] using a color assay in the identical genetic background. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=4747183 Mon, 25 Apr 2011 13:07:13 +0100 4747183 http://www.medworm.com/index.php?rid=4839686&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1857 AbstractMost scoring assays for yeast prions are dependent on specific genetic markers and constructs that differ for each prion. Here we describe a simple colour assay for the [URE3] prion that works in the 74D‐964 strain frequently used to score the [PSI+] prion. Although this assay can only be used to score for [URE3] in the [psi−] version of the strain, it makes it easier to examine the effects of host mutations or environmental changes on [URE3] or [PSI+] using a colour assay in the identical genetic background. Copyright © 2011 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=4839686 Sun, 24 Apr 2011 23:00:00 +0100 4839686 http://www.medworm.com/index.php?rid=4839687&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1856 AbstractThe investigation of protein–protein interactions is an essential part of biological research. To obtain a deeper insight into regulatory protein networks, the identification of the components, domains and especially single residues that are involved in these interactions is helpful. A widespread and attractive genetic tool for investigation of protein–protein interactions is the yeast two‐hybrid system. This method enables large‐scale screens and its application is cheap and relatively simple. For identification of the amino acids in a protein sequence that are essential for interaction with a specific partner, yeast two‐hybrid assays can be combined with random mutagenesis of the sequence of interest. A common problem with such an experiment is the generation of stop co... Yeast journals http://www.medworm.com/rss/comments.php?id=4839687 Sun, 10 Apr 2011 23:00:00 +0100 4839687 http://www.medworm.com/index.php?rid=4703552&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1856 AbstractThe investigation of protein‐protein interactions is an essential part of biological research. To obtain a deeper insight into regulatory protein networks, the identification of the components, domains and especially single residues that are involved in these interactions is helpful. A widespread and attractive genetic tool for investigation of protein‐protein interactions is the yeast two‐hybrid system. This method enables large‐scale screens, and its application is cheap and relatively simple. For identification of the amino acids in a protein sequence that are essential for interaction with a specific partner, yeast two‐hybrid assays can be combined with random mutagenesis of the sequence of interest. A common problem with such an experiment is the generation of stop c... Yeast journals http://www.medworm.com/rss/comments.php?id=4703552 Thu, 31 Mar 2011 23:00:00 +0100 4703552 http://www.medworm.com/index.php?rid=4663240&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1855 AbstractRandom spore analysis is a fundamental tool of yeast genetics for determining gene linkage and generation of recombinants progeny by genetic crosses. Experimentally it involves treatment of a mating mix with enzymes like zymolyase or lyticase, that selectively lyse the cell wall of vegetative cells rather than the spores. Here, we describe a method whereby the relative refractory nature of the spores to treatment with elevated temperature and repeated freezing thawing facilitates random spore analysis at low cost in case of fission yeast, Schizosaccharomyces pombe. Because of similar properties of spores in the budding yeast, this method should prove to be useful for random spore analysis both in the budding and fission yeast. Copyright © 2011 John Wiley & Sons, Ltd. (Source: ... Yeast journals http://www.medworm.com/rss/comments.php?id=4663240 Thu, 31 Mar 2011 23:00:00 +0100 4663240 http://www.medworm.com/index.php?rid=4794197&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1854 AbstractThe intensity of amyloid‐bound thioflavine T fluorescence was studied in crude lysates of yeast strains carrying mutations in the ADE1 or ADE2 genes and accumulating the red pigment (a result of polymerization of aminoimidazoleribotide), and in white isogenic strains–either adenine prototrophs or carrying mutations at the first stages of purine biosynthesis. We found that the red pigment leads to a drop of amyloid content. This result, along with the data on separation of protein polymers of white and red strains in PAGE, suggests that the red pigment inhibits amyloid fibril formation. The differences in transmission of the thioflavine T fluorescence pattern by cytoduction and in blot‐hybridization of pellet proteins of red and white [PSI+] strains with Sup35p antibodies conf... Yeast journals http://www.medworm.com/rss/comments.php?id=4794197 Wed, 23 Mar 2011 00:00:00 +0100 4794197 http://www.medworm.com/index.php?rid=4630835&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1854 AbstractThe intensity of amyloid bound Thioflavine T fluorescence was studied in crude lysates of yeast strains carrying mutations in ADE1 or ADE2 genes and accumulating the red pigment (a result of polymerization of aminoimidazoleribotide), and in white isogenic strains—either adenine prototrophs or carrying mutations at the first stages of purine biosynthesis. We found that the red pigment leads to a drop of amyloid content. This result, along with the data on separation of protein polymers of white and red strains in PAGE, suggests that the red pigment inhibits amyloid fibril formation. The differences in transmission of the Thioflavine T fluorescence pattern by cytoduction and in blot‐hybridization of pellet proteins of red and white [PSI+] strains with Sup35p antibodies confirmed ... Yeast journals http://www.medworm.com/rss/comments.php?id=4630835 Tue, 01 Mar 2011 00:00:00 +0100 4630835 http://www.medworm.com/index.php?rid=4531428&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1853 AbstractWe characterized the Schizosaccharomyces pombe arc3 gene, whose product shares sequence homology with that of the budding yeast ARC18 and human ARPC3/p21 subunits of the Arp2/3 complex. Our data showed that Arc3p co‐localizes with F‐actin patches at the cell ends, but not with F‐actin cables or the equatorial actin ring, and binds other subunits of the Arp2/3 complex. Gene deletion analysis showed that arc3 is essential for viability. When arc3 expression was repressed, F‐actin patches became dispersed throughout the cell with greatly reduced mobility. Furthermore in arc3‐repressed cells, endocytosis was also inhibited. Human ARPC3 rescued the viability of the S. pombearc3 null mutant; in addition, ARPC3 also localizes to F‐actin patches in human cells. These data sugge... Yeast journals http://www.medworm.com/rss/comments.php?id=4531428 Tue, 01 Mar 2011 00:00:00 +0100 4531428 http://www.medworm.com/index.php?rid=4527442&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1852 In this study, 6EA1 cells were transformed with plasmids carrying either RPL12A or RPL12B, and the transcriptional profiles of wild‐type W303, 6EA1 and the transformed cells grown in synthetic complete medium were examined by microarray analysis. Transcription of PHO84, a gene encoding a high‐affinity phosphate transporter, was drastically suppressed in 6EA1. PHO84 expression is induced under phosphate‐limiting conditions. Therefore, cells were grown in low‐phosphate medium and transcripts encoding the PHO pathway proteins were quantified by qRT‐PCR. The high‐affinity phosphate transporters and repressible phosphatases were suppressed, while PHO4, a PHO pathway transcription activator, was up regulated in 6EA1. Accordingly, phosphate transport and acidic phosphatase activities ... Yeast journals http://www.medworm.com/rss/comments.php?id=4527442 Sun, 27 Feb 2011 00:00:00 +0100 4527442 http://www.medworm.com/index.php?rid=4527441&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1851 AbstractThe progression of meiosis is controlled by a number of gene‐expression systems in the fission yeast Schizosaccharomyces pombe. A forkhead‐type transcription factor Mei4 activates a number of genes essential for progression from the middle to late stages of meiosis, which include meiosis I, meiosis II and sporulation. The mei4‐deletion mutant (mei4Δ) arrests after meiotic prophase and does not enter meiosis I. To further analyze the Mei4 function, we isolated novel temperature‐sensitive mei4 alleles. The two alleles isolated in the initial screen turned out to contain a substitution at N136 in the forkhead DNA‐binding domain. Among site‐directed mutants that carried a point mutation at this position, the mei4‐N136A mutant showed the most severe temperature‐sensitiv... Yeast journals http://www.medworm.com/rss/comments.php?id=4527441 Sun, 27 Feb 2011 00:00:00 +0100 4527441 http://www.medworm.com/index.php?rid=4527440&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1850 AbstractProteins exit the endoplasmic reticulum (ER) in vesicles pinching off from the membrane at sites covered by the COPII coat, which consists of Sec23/24p and Sec13/31p. We have shown that the glycoprotein Hsp150 exits the ER in the absence of Sec13p or any member of the Sec24p family. The determinant responsible for this resides in the C‐terminal domain of Hsp150 (CTD). Here, A‐type and B‐type Walker motifs were identified in the CTD. Authentic Hsp150 from the yeast culture medium, as well as Hsp150 and the CTD fragment produced in E. coli, exhibited ATPase activity nearly three times higher than the published activity of the ER chaperone Kar2p/BiP. Deletion of the Walker motif, and a K335A mutation in it, abolished the ATPase activity. Hsp150 homologs Pir3p and Pir4p differing... Yeast journals http://www.medworm.com/rss/comments.php?id=4527440 Tue, 01 Feb 2011 00:00:00 +0100 4527440 http://www.medworm.com/index.php?rid=4476991&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1849 AbstractFoam formation in fermentations conducted by Saccharomyces cerevisiae, either at the beginning of the fermentation process or at the end in the case of sparkling wines, is due to a large extent, to cell wall mannoproteins, which provide hydrophobicity to the yeast cells and favor their floating index as well as stabilization of the foam. The foam may be an undesirable by‐product if it accumulates on top of the fermentation tanks, but its formation is a good property in either beer or sparkling wines. It is, therefore, important to know the yeast genes involved in foam formation, in order to suppress or potentiate their expression according to the end product to be obtained.The present work identifies and characterizes for the first time in an oenological S. cerevisiae strain a ge... Yeast journals http://www.medworm.com/rss/comments.php?id=4476991 Tue, 01 Feb 2011 00:00:00 +0100 4476991 http://www.medworm.com/index.php?rid=4464050&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1848 AbstractThis work studies the competition and potential hybrid generation between the species Saccharomyces cerevisiae and Saccharomyces kudriavzevii in a wine‐model environment. Our main goal is to understand why S. kudriavzevii has not been found in wine fermentations whilst their hybrids are present. Auxotrophic mutants (Ura– and Lys–) were used to favor the selection of hybrids and to specifically differentiate both species in mixed fermentations carried out at different temperatures (17, 24 and 31ºC). Both yeasts showed a reduction in their maximum specific growth rates in mixed fermentations, indicating a clear antagonistic effect between both microorganisms. Temperature played an important role on this competition. In this way, S. kudriavzevii was less affected at 17ºC, but ... Yeast journals http://www.medworm.com/rss/comments.php?id=4464050 Tue, 01 Feb 2011 00:00:00 +0100 4464050 http://www.medworm.com/index.php?rid=4454662&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1847 AbstractThe Rec10 protein, a component of the linear elements forming along sister chromatids in meiotic prophase of Schizosaccharomyces pombe, plays an important role in activation of Rec12 for double‐strand break formation, and thus initiation of recombination between homologous chromosomes. Recombination between homologous chromosomes was reduced in homozygous crosses of the C‐terminal truncation mutant rec10‐155 (moderately) and the full deletion allele rec10‐175 (strongly). Both alleles were also tested in two assays for intrachromosomal recombination (PS1 and VL1), and showed only slight reductions, while deletion of rec12 led to a 13‐fold reduction. The even stronger reductions in rec10rec12 double deletion crosses indicate partially redundant functions of Rec10 and Rec12 ... Yeast journals http://www.medworm.com/rss/comments.php?id=4454662 Tue, 01 Feb 2011 00:00:00 +0100 4454662 http://www.medworm.com/index.php?rid=4432699&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1846 AbstractLocal anesthetics and antipsychotic phenothiazines cause a rapid shutdown of both actin polarization and translation initiation in yeast cells, like some environmental stresses. These compounds all have an amphiphilic structure, surfactant activity, and the ability to lyse yeast cells. To elucidate the structures responsible for the shutdown activity and cell lysis, we investigated a variety of amphiphiles. In the hydrophobic region, the straight alkyl structure was sufficient for the shutdown of actin polarization and translational initiation. In the hydrophilic region of the straight alkyl compounds, cationic trimethyl ammonium (TMA) and nonionic hydroxyl structure (alcohols) shut down both reactions, while an anionic structure, sulfate, with a long alkyl chain (≥C6) shut down ... Yeast journals http://www.medworm.com/rss/comments.php?id=4432699 Tue, 01 Feb 2011 00:00:00 +0100 4432699 http://www.medworm.com/index.php?rid=4531429&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1845 AbstractScheffersomyces stipitis and the closely related yeast Candida shehatae assimilated the L‐amino acids glutamate, aspartate and proline as both carbon and nitrogen sole sources. We also found this rarely investigated ability in ascomycetous species such as Candida glabrata, C. reukaufii, C. utilis, Debaryomyces hansenii, Kluyveromyces lactis, K. marxianus, Candida albicans, L. elongisporus, Meyerozyma guilliermondii, C.maltosa, Pichia capsulata and Yarrowia lipolytica and in basidiomycetous species such as Rhodotorula rubra and Trichosporon beigelii. Glutamate was a very efficient carbon source for Sc. stipitis, which enabled a high biomass yield/mole, although the growth rate was lower when compared to growth on glucose medium. The cells secreted waste ammonium during growth on g... Yeast journals http://www.medworm.com/rss/comments.php?id=4531429 Wed, 12 Jan 2011 00:00:00 +0100 4531429 http://www.medworm.com/index.php?rid=4337057&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1844 AbstractAlcohol dehydrogenases catalyze the reversible oxidation of alcohols to aldehydes or ketones, with concomitant reduction of NAD+ or NADP+. Adh1p is responsible for reduction of acetaldehyde to ethanol while Adh2p catalyzes the reverse reaction, the oxidation of ethanol to acetaldehyde. Lack of Adh1p shifts the cellular redox balance towards excess NADH/NADPH and acetaldehyde while absence of Adh2p does the opposite. Yeast mutant adh1Δ had slow growth rate whereas adh2Δ grew like the isogenic WT during pre diauxic shift fermentative metabolism. After 48 hours WT and mutants reached the same number of viable cells. When exponentially growing (LOG) cells were exposed to Calcofluor White only mutant adh1Δ displayed an irregular deposition of chitin. Quantitative analyses of both LOG... Yeast journals http://www.medworm.com/rss/comments.php?id=4337057 Mon, 10 Jan 2011 00:00:00 +0100 4337057 http://www.medworm.com/index.php?rid=4330270&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1842 AbstractStress granules (SGs) and processing bodies (P‐bodies) are cytoplasmic domains and play a role in the control of translation and mRNA turnover in mammalian cells subjected to environmental stress. Recent studies revealed that SGs also form in the budding yeast Saccharomyces cerevisiae in response to glucose depletion and robust heat shock. However, information about the types of stress that cause budding yeast SGs is quite limited. Here we demonstrate that severe ethanol stress generates budding yeast SGs in a manner independent of the phosphorylation of eIF2α. The concentration that generated budding yeast SGs (above 10 %) was higher than that causing P‐bodies (more than 6 %), and P‐bodies were assembled prior to SGs. As well as mammalian SGs, the assembly of budding yeast ... Yeast journals http://www.medworm.com/rss/comments.php?id=4330270 Sun, 09 Jan 2011 00:00:00 +0100 4330270 http://www.medworm.com/index.php?rid=4337056&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1845 AbstractSc. stipitis and the closely related yeast Scheffersomyces shehatae assimilated the L‐amino acids glutamate, aspartate and proline as both, sole carbon and nitrogen sources. We found this in yeasts rarely investigated ability as well as in ascomycetous species like C. glabratat,C. reukaufii, C. utilis, Debaryomyces hansenii, Kluyveromyces lactis, K. marxianus, Lodderomyces albicans, L. elongisporus, L. guilliermondii, L. maltose, Pichia capsulata and Yarrowia lipolytica and in basidiomycetous species like Rhodotorula rubra and Trichosporon beigelii. Glutamate was a very efficient carbon source for Sc. stipitis, which enabled a high biomass yield per Mol although the growth rate was lower if compared to growth on glucose medium. Cells secreted waste ammonium during growth on solel... Yeast journals http://www.medworm.com/rss/comments.php?id=4337056 Sat, 01 Jan 2011 00:00:00 +0100 4337056 http://www.medworm.com/index.php?rid=4330269&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1843 AbstractWe quantified the growth behavior of all available single‐gene deletion and overexpression strains of budding yeast. Genome‐wide analyses enabled the extraction of the genes and identification of the functional categories for which genetic perturbation caused the change of growth behavior. Statistical analyses revealed defective growth for 646 deletion and 1302 overexpression strains. We classified these deleted and overexpressed genes into known functional categories, and identified several functional categories having fragility and robustness for the cellular growth. We also screened the deletion and overexpression strains that exhibited a significantly higher growth rate than the strain without genetic perturbation, and found 3 deletion and 2 overexpression strains were high... Yeast journals http://www.medworm.com/rss/comments.php?id=4330269 Sat, 01 Jan 2011 00:00:00 +0100 4330269 http://www.medworm.com/index.php?rid=4355304&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1838 AbstractSophorolipids produced by the non‐pathogenic yeast Candida bombicola ATCC 22214 are glycolipid biosurfactants applied commercially as biodegradable and eco‐friendly detergents. Their low cell toxicity, excellent wetting capability and antimicrobial activity attract the attention of high‐value markets, such as the cosmetic and pharmaceutical industries. Although sophorolipid production yields have been increased by the optimization of fermentation parameters and feed sources, the biosynthetic pathway and genetic mechanism behind sophorolipid production still remains unclear. Here we identify a UDP‐glucosyltransferase gene, UGTB1, with a key function in this economically important pathway. The protein shows sequence and structural homology to several bacterial glycosyltransfe... Yeast journals http://www.medworm.com/rss/comments.php?id=4355304 Thu, 09 Dec 2010 00:00:00 +0100 4355304 http://www.medworm.com/index.php?rid=4244646&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1838 AbstractSophorolipids produced by the non‐pathogenic yeast Candida bombicola ATCC 22214 are glycolipid biosurfactants applied commercially as biodegradable and eco‐friendly detergents. Their low cell toxicity, excellent wetting capability and antimicrobial activity attract attention of high‐value markets such as cosmetical and pharmaceutical industry. Though sophorolipid production yields were increased by optimization of fermentation parameters and feed source, the biosynthetic pathway and the genetic mechanism behind sophorolipid production still remains unclear. Here we identify a UDP‐glucosyltransferase gene UGTB1 with a key function in this economically important pathway. The protein shows sequence and structural homology to several bacterial glycosyltransferases involved in m... Yeast journals http://www.medworm.com/rss/comments.php?id=4244646 Thu, 09 Dec 2010 00:00:00 +0100 4244646 http://www.medworm.com/index.php?rid=4244645&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1839 AbstractCandida albicans undergoes a reversible morphological transition from single yeast cells to pseudohyphal and hyphal filaments. In this organism PKA, coded by two catalytic subunits (TPK1 and TPK2) and one regulatory subunit (BCY1), mediates basic cellular processes, such as the yeast to hypha transition and cell cycle regulation. It is known that both Tpk isoforms play positive roles in vegetative growth and filamentation, though distinct roles have been found in virulence, stress response and glycogen storage. However, little is known regarding the participation of Tpk1p and/or Tpk2p in pseudohyphal development. This point was addressed using several C. albicans PKA mutants having heterozygous or homozygous deletions of TPK1 and/or TPK2 in different BCY1 genetic backgrounds. We ob... Yeast journals http://www.medworm.com/rss/comments.php?id=4244645 Thu, 09 Dec 2010 00:00:00 +0100 4244645 http://www.medworm.com/index.php?rid=4264306&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1841 AbstractPCR‐based gene targeting technologies have previously been developed for Candida albicans molecular genetic manipulation. Modular marker plasmids for the functional analysis of C. albicans genes have been generated to delete genes, exchange promoters, and tag genes with GFP. Here, we have embedded two fluorescent proteins encoded by Venus and yEmCherry into the pFA‐plasmid series and demonstrate their usefulness in dual colour microscopy. To this end we analysed the localization of C. albicans homologs of Pil1 and Lsp1, which in S. cerevisiae are components of eisosomes. We find that Pil1/Lsp1‐containing eisosomes are cortical protein complexes in C. albicans. Pil1 and Lsp1, tagged with either GFP or yEmCherry, strictly co‐localize during all growth stages. Eisosomes, howev... Yeast journals http://www.medworm.com/rss/comments.php?id=4264306 Wed, 01 Dec 2010 00:00:00 +0100 4264306 http://www.medworm.com/index.php?rid=4244644&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1840 AbstractSc. stipitis PJH was mutagenized by random integrative mutagenesis and the integrants were screened for lacking the ability to grow with glutamate as sole carbon source. One of the two isolated mutants was damaged in the COX5 gene, which encodes a subunit of the cytochrome c oxidase. BLAST searches in the genome of Sc. stipitis revealed that only one singular COX5 gene exists in Sc. stipitis, in contrast to Saccharomyces cerevisiae, where two homologous genes are present. Mutant cells had lost the ability to grow with the amino acids glutamate, proline or aspartate and other non‐fermentable carbon sources such as acetic acid and ethanol as sole carbon sources. Biomass formation of the mutant cells in medium containing glucose or xylose as carbon source was lower compared with the... Yeast journals http://www.medworm.com/rss/comments.php?id=4244644 Wed, 01 Dec 2010 00:00:00 +0100 4244644 http://www.medworm.com/index.php?rid=4224121&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1724 AbstractIn order to keep subscribers up‐to‐date with the latest developments in their field, this current awareness service is provided by John Wiley & Sons and contains newly‐published material on yeasts. Each bibliography is divided into 10 sections. 1 Reviews; 2 General; 3 Biochemistry; 4 Biotechnology; 5 Cell Biology; 6 Gene Expression; 7 Genetics; 8 Physiology; 9 Medical Mycology; 10 Recombinant DNA Technology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. (5 weeks journals ‐ search completed 13th. Oct. 2010) (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=4224121 Wed, 01 Dec 2010 00:00:00 +0100 4224121 http://www.medworm.com/index.php?rid=4355303&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1837 We examined Cypridina luciferase levels induced by MMS and three antitumour agents using a set of BY4741‐derived deletion mutants, each defective in a DNA repair pathway or DNA damage checkpoint. Luciferase activities were particularly enhanced in mutant strains with mms2Δ and mag1Δ by exposure to MMS, rad59Δ and mlh1Δ to camptothecin and mms2Δ and mlh1Δ to mitomycin C, respectively, compared with their parent strains. Enhanced reporter activities were also found in some DNA repair mutants with cisplatin. These observations suggest that this Cypridina secretory luciferase reporter assay using yeast DNA repair mutants offers convenient and sensitive detection of the potential genotoxicity of numerous compounds, including antitumour drugs and studying the mechanisms of DNA damage res... Yeast journals http://www.medworm.com/rss/comments.php?id=4355303 Mon, 29 Nov 2010 00:00:00 +0100 4355303 http://www.medworm.com/index.php?rid=4154748&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1833 AbstractIt has been difficult to develop molecular tools for studying the fungal pathogen Candida albicans because it uses a non‐standard genetic code and is diploid without a complete sexual cycle. Vector systems with regulatable promoters to produce conditional mutants, epitope tags for protein detection, and recyclable selection markers are useful for functional study of genes. However, most currently available vectors contain only a subset of desired properties, which limits their application. To combine several useful properties in one vector, the vector pTET25 was initially modified into pTET25M so that the URA3 gene flanked by dpl200 could be used repetitively. To enable more choices for cloning, a multiple cloning site was introduced at both ends of GFP in pTET25M. GFP expression... Yeast journals http://www.medworm.com/rss/comments.php?id=4154748 Thu, 11 Nov 2010 00:00:00 +0100 4154748 http://www.medworm.com/index.php?rid=4212866&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1837 We examined Cypridina luciferase levels induced by MMS and three antitumor agents using a set of BY4741‐derived deletion mutants, each defective in a DNA repair pathway or DNA damage checkpoint. Luciferase activities were particularly enhanced in mutant strains with mms2Δ and mag1Δ by exposure to MMS, rad59Δ and mlh1Δ to camptothecin, and mms2Δ and mlh1Δ to mitomycin C, respectively, compared with their parent strain. Enhanced reporter activities were also found in some DNA repair mutants with cisplatin. These observations suggest that this Cypridina secretory luciferase reporter assay using yeast DNA repair mutants offers convenient and sensitive detection of potential genotoxicity of numerous compounds including antitumor drugs, and for studying mechanisms of DNA damage response ... Yeast journals http://www.medworm.com/rss/comments.php?id=4212866 Mon, 01 Nov 2010 00:00:00 +0100 4212866 http://www.medworm.com/index.php?rid=4200055&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1836 We describe a new cloning‐free strategy to delete genes in the opportunistic pathogenic yeast Candida lusitaniae. We first constructed two ura3Δ strains in C. lusitaniae for their use in transformation experiments. One was deleted for the entire URA3 coding sequence; the other possessed a partial deletion within the coding region which was used to determine the minimum amount of homology required for efficient homologous recombination by double crossing‐over of a linear DNA fragment restoring URA3 expression. This amount was estimated to 200 bp on each side of the DNA fragment. This data constituted the basis of the development of a strategy to construct DNA cassettes for gene deletion by a cloning‐free overlapping PCR method. Two cassettes were necessary in two successive transform... Yeast journals http://www.medworm.com/rss/comments.php?id=4200055 Mon, 01 Nov 2010 00:00:00 +0100 4200055 http://www.medworm.com/index.php?rid=4196277&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1835 AbstractTo humanize the glycosylation pathway in the yeast Pichia pastoris we developed several combinatorial genetic libraries and used them to properly localize active eukaryotic mannosidases and sugar transferases. Here we report the details of the fusion of up to 66 N‐terminal targeting sequences of fungal type II membrane proteins to 33 catalytic domains of heterologous glycosylation enzymes. We show that while it is difficult to predict which leader/catalytic domain will result in the desired activity, analysis of the fusion protein libraries allows for the selection of the leader/catalytic domain combinations that function properly. This combinatorial approach together with a high throughput screening protocol has allowed us to humanize the yeast glycosylation pathway to secrete h... Yeast journals http://www.medworm.com/rss/comments.php?id=4196277 Mon, 01 Nov 2010 00:00:00 +0100 4196277 http://www.medworm.com/index.php?rid=4167111&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1834 In this study, we characterized haploid and diploid strains of Saccharomyces cerevisiae at each of the key stages in the cell cycle, and determined if there were relationships between cellular and organelle volumes. We then compared these results with SXT data obtained from Schizosaccharomyces pombe, the three main phenotypes displayed by the opportunistic yeast pathogen Candida albicans, and from a coff1‐22 mutant strain of Saccharomyces cerevisiae. This comparison revealed that volumetric ratios were invariant irrespective of yeast strain, ploidy or morphology, leading to the conclusion these volumetric ratios are common in all yeasts. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=4167111 Mon, 01 Nov 2010 00:00:00 +0100 4167111 http://www.medworm.com/index.php?rid=4154747&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1832 In this study, the isolation of two PIR (Proteins with Internal Repeats) genes i.e. PpPIR1 and PpPIR2, from methylotrophic yeast Pichia pastoris has been reported. The PIR1 and PIR2 gene's open reading frame was found to contain 1068 and 972 bases, respectively. The sequence homology search showed a homologous conserved repeat of PIR yeast block (SQIGDGQIQATT) in both the proteins. The PIR yeast block was present eight times in the PpPir1p and four times in the PpPir2p protein. Both proteins showed conserved glutamine (Q) and aspartic acid (D) in the repeated sequences indicating a possible alkali sensitive β‐1,3 glucan ester linkage. The fusion constructs of PpPir1‐2p and Enhanced Green Fluorescent Protein (EGFP) were developed for yeast cell surface display. The immunofluorescence a... Yeast journals http://www.medworm.com/rss/comments.php?id=4154747 Mon, 01 Nov 2010 00:00:00 +0100 4154747 http://www.medworm.com/index.php?rid=4132507&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1723 AbstractIn order to keep subscribers up‐to‐date with the latest developments in their field, this current awareness service is provided by John Wiley & Sons and contains newly‐published material on yeasts. Each bibliography is divided into 10 sections. 1 Reviews; 2 General; 3 Biochemistry; 4 Biotechnology; 5 Cell Biology; 6 Gene Expression; 7 Genetics; 8 Physiology; 9 Medical Mycology; 10 Recombinant DNA Technology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. (5 weeks journals ‐ search completed 8th. Sept. 2010) (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=4132507 Mon, 01 Nov 2010 00:00:00 +0100 4132507 http://www.medworm.com/index.php?rid=4189321&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1830 AbstractCaffeine exerts pleiotropic effects on eukaryotic cells via its ability to act as a low‐affinity adenosine analogue. Here we report that the genes HSE1, RTS3, SDS23 and SDS24 confer caffeine resistance when overexpressed in S. cerevisiae. The Hse1 protein functions in ubiquitin‐dependent vacuolar protein sorting, whereas the other proteins are poorly characterized. Bioinformatic analysis of genetic and physical interaction data linked Rts3 and Sds23/24 to the phosphatase 2A‐like Sit4 pathway. Combinatorial deletions of the identified suppressor genes conferred varying levels of caffeine hypersensitivity. For hse1Δ and rts3Δ mutants, caffeine sensitivity was partially rescued by sorbitol osmostabilization, suggesting possible cell wall integrity defects in these strains. Rap... Yeast journals http://www.medworm.com/rss/comments.php?id=4189321 Fri, 29 Oct 2010 00:00:00 +0100 4189321 http://www.medworm.com/index.php?rid=4117059&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1831 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=4117059 Thu, 30 Sep 2010 23:00:00 +0100 4117059 http://www.medworm.com/index.php?rid=4044354&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1829 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=4044354 Thu, 30 Sep 2010 23:00:00 +0100 4044354 http://www.medworm.com/index.php?rid=4026790&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1722 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=4026790 Thu, 30 Sep 2010 23:00:00 +0100 4026790 http://www.medworm.com/index.php?rid=3992635&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1827 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3992635 Tue, 31 Aug 2010 23:00:00 +0100 3992635 http://www.medworm.com/index.php?rid=3964950&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1825 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3964950 Tue, 31 Aug 2010 23:00:00 +0100 3964950 http://www.medworm.com/index.php?rid=3957360&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1824 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3957360 Tue, 31 Aug 2010 23:00:00 +0100 3957360 http://www.medworm.com/index.php?rid=3942240&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1809 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3942240 Tue, 31 Aug 2010 23:00:00 +0100 3942240 http://www.medworm.com/index.php?rid=3924252&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1721 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3924252 Tue, 31 Aug 2010 23:00:00 +0100 3924252 http://www.medworm.com/index.php?rid=3906930&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1819 (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3906930 Sat, 31 Jul 2010 23:00:00 +0100 3906930 http://www.medworm.com/index.php?rid=3895274&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1817 (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3895274 Sat, 31 Jul 2010 23:00:00 +0100 3895274 http://www.medworm.com/index.php?rid=3864845&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1720 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3864845 Sat, 31 Jul 2010 23:00:00 +0100 3864845 http://www.medworm.com/index.php?rid=3864844&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1784 (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3864844 Sat, 31 Jul 2010 23:00:00 +0100 3864844 http://www.medworm.com/index.php?rid=3801847&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1796 Vaccine strategies that target dendritic cells to elicit potent cellular immunity are the subject of intense research. Here we report that the genetically engineered yeast Saccharomyces cerevisiae, expressing the full-length tumour-associated antigen NY-ESO-1, is a versatile host for protein production. Exposing dendritic cells (DCs) to soluble NY-ESO-1 protein linked to the yeast a-agglutinin 2 protein (Aga2p) protein resulted in protein uptake, processing and MHC class I cross-presentation of NY-ESO-1-derived peptides. The process of antigen uptake and cross-presentation was dependent on the glycosylation pattern of NY-ESO-1-Aga2p protein and the presence of accessible mannose receptors. In addition, NY-ESO-1-Aga2p protein uptake by dendritic cells resulted in recognition by HLA-DP4 NY-E... Yeast journals http://www.medworm.com/rss/comments.php?id=3801847 Thu, 29 Jul 2010 23:00:00 +0100 3801847 http://www.medworm.com/index.php?rid=3753280&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1807 To obtain insight into the genome-wide transcriptional response of heterologous carotenoid production in Saccharomyces cerevisiae, the transcriptome of two different S. cerevisiae strains overexpressing carotenogenic genes from the yeast Xanthophyllomyces dendrorhous grown in carbon-limited chemostat cultures was analysed. The strains exhibited different absolute carotenoid levels as well as different intermediate profiles. These discrepancies were further sustained by the difference of the transcriptional response exhibited by the two strains. Transcriptome analysis of the strain producing high carotenoid levels resulted in specific induction of genes involved in pleiotropic drug resistance (PDR). These genes encode ABC-type and major facilitator transporters which are reported to be invo... Yeast journals http://www.medworm.com/rss/comments.php?id=3753280 Wed, 14 Jul 2010 23:00:00 +0100 3753280 http://www.medworm.com/index.php?rid=3753281&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1808 Here we describe a new procedure for ascospore isolation from cultures containing a majority of unsporulated vegetative cells of Saccharomyces cerevisiae. The EZ ascospore isolation procedure relies on the combination of two conventional protocols, diethyl ether treatment and modified zymolyase treatment, allowing a significant increase in the efficiency of ascospore isolation and consequently enabling a large number of meiotic offspring to be efficiently obtained and screened, thus improving the efficacy of genetic research and the genetic selection of S. cerevisiae strains. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3753281 Tue, 13 Jul 2010 23:00:00 +0100 3753281 http://www.medworm.com/index.php?rid=3746345&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1806 The widely used pESC vector series (Stratagene, La Jolla, CA, USA) with the bidirectional GAL1/GAL10 promoter provides the possibility of simultaneously expressing two different genes from a single vector in Saccharomyces cerevisiae. This system can be induced by galactose and is repressed by glucose. Since S. cerevisiae prefers glucose as a carbon source, and since its growth rate is higher in glucose than in galactose-containing media, we compared and evaluated seven different promoters expressed during growth on glucose (pTEF1, pADH1, pTPI1, pHXT7, pTDH3, pPGK1 and pPYK1) with two strong galactose-induced promoters (pGAL1 and pGAL10), using lacZ as a reporter gene and measuring LacZ activity in batch and continuous cultivation. TEF1 and PGK1 promoters showed the most constant activity p... Yeast journals http://www.medworm.com/rss/comments.php?id=3746345 Mon, 12 Jul 2010 23:00:00 +0100 3746345 http://www.medworm.com/index.php?rid=3746346&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1805 Regulated protein destruction by the proteasome is crucial for the maintenance of normal cellular homeostasis. Much of our understanding of proteasome function stems from the use of drugs that inhibit its activity. Curiously, despite the importance of proteasomal proteolysis, previous studies have found that proliferation of the yeast Saccharomyces cerevisiae is relatively resistant to the effects of proteasome inhibitors such as MG132, even in the presence of mutations that increase inhibitor levels in cells. We reasoned that part of the resistance of S. cerevisiae to proteasome inhibitors stems from the fact that most proteasome inhibitors preferentially target the chymotryptic activity of the proteasome, and that the caspase-like and tryptic sites within the 20S core could compensate fo... Yeast journals http://www.medworm.com/rss/comments.php?id=3746346 Sun, 11 Jul 2010 23:00:00 +0100 3746346 http://www.medworm.com/index.php?rid=3721390&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1804 The Saccharomyces cerevisiae protein Knr4 is composed of a globular central core flanked by two natively disordered regions. Although the central part of the protein holds most of its biological function, the N-terminal domain (amino acids 1-80) is essential in the absence of a functional CWI pathway. We show that this specific protein domain is required for the proper cellular localization of Knr4 at sites of polarized growth during vegetative growth and sexual differentiation (bud tip and 'shmoo' tip). Moreover, Knr4 N-terminal domain is also necessary for cell cycle arrest and shmoo formation in response to pheromone to occur at the correct speed. Thus, the presence of Knr4 at the incipient mating projection site seems important for the establishment of the following polarized growth. C... Yeast journals http://www.medworm.com/rss/comments.php?id=3721390 Fri, 02 Jul 2010 23:00:00 +0100 3721390 http://www.medworm.com/index.php?rid=3721395&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1800 A general system has been devised for the in vivo construction of Candida albicans integrative vectors in Saccharomyces cerevisiae. The system is especially useful for the integration of genes in C. albicans that cannot be propagated in Escherichia coli, possibly because of their toxic effects. The ligation of S. cerevisiae 2 µ sequences to a C. albicans integrative vector permits in vivo maintenance and gap repair cloning within S. cerevisiae. After the vector assembly, it can be purified from S. cerevisiae or amplified by PCR and then used for transformation of C. albicans. The S. cerevisiae 2 µ sequence is completely removed by linearization prior to C. albicans transformation, such that no unwanted DNA is transferred in the final construct. The system was successfully used to clone a... Yeast journals http://www.medworm.com/rss/comments.php?id=3721395 Thu, 01 Jul 2010 23:00:00 +0100 3721395 http://www.medworm.com/index.php?rid=3721394&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1802 We report on the cloning, heterologous expression and analysis in S. cerevisiae of this novel ScHAP4 orthologue. From these experiments we could conclude that, as with HpHAP4-A, the novel orthologue, designated HpHAP4-B, could functionally replace the S. cerevisiae gene but to a lesser extent. The relationship between the presence of the additional cis-binding motif and the weaker potential as a HAP4 functional homologue is discussed. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3721394 Thu, 01 Jul 2010 23:00:00 +0100 3721394 http://www.medworm.com/index.php?rid=3721393&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1797 Many of the genes and enzymes critical for assembly and biogenesis of yeast cell walls remain unidentified or poorly characterized. Therefore, we designed a high throughput genomic screen for defects in anchoring of GPI-cell wall proteins (GPI-CWPs), based on quantification of a secreted GFP-Sag1p fusion protein. Saccharomyces cerevisiae diploid deletion strains were transformed with a plasmid expressing the fusion protein under a GPD promoter, then GFP fluorescence was determined in culture supernatants after mid-exponential growth. Variability in the amount of fluorescent marker secreted into the medium was reduced by growth at 18 °C in buffered defined medium in the presence of sorbitol. Secondary screens included immunoblotting for GFP, fluorescence emission spectra, cell surface fluo... Yeast journals http://www.medworm.com/rss/comments.php?id=3721393 Thu, 01 Jul 2010 23:00:00 +0100 3721393 http://www.medworm.com/index.php?rid=3721392&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1801 In this study, we used atomic force microscopy (AFM) to visualize the cell surface topography and to determine cell wall nanomechanical properties of yeast mutants defective in cell wall architecture. While all mutants investigated showed some alteration in cell surface topography, this alteration was particularly salient in mutants defective in [beta]-glucan elongation (gas1), chitin synthesis (chs3) and cross-linkages between chitin and [beta]-glucan (crh1crh2). In addition, these alterations in surface topology were accompanied by increased roughness of the cell. From force-indentation curves, the Young's modulus was determined, as it gives a measure of the elasticity of the cell wall. A value of [sim]1.6 MPa was obtained for the cell walls of the wild-type strain in exponential and sta... Yeast journals http://www.medworm.com/rss/comments.php?id=3721392 Thu, 01 Jul 2010 23:00:00 +0100 3721392 http://www.medworm.com/index.php?rid=3721391&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1803 Two temperature-sensitive Saccharomyces cerevisiae mutants, sec59-1 and dpm1-6, impaired, respectively, in dolichol kinase (Sec59p) and dolichyl phosphate mannose (DolPMan) synthase (Dpm1p), have an aberrant cell wall structure and composition. We tested their sensitivity to four classes of antifungal drugs used in clinical practice: 5-fluorocytosine, amphotericin B, caspofungin and itraconasole. The strains were resistant to itraconazole and sensitive to the other drugs used. The minimal inhibitory concentration (MIC) of caspofungin and amphotericin B was two-fold lower for sec59-1 and dpm1-6 than for the respective wild-type strains. The sensitivity of both mutants could be brought back to the wild-type level by a multicopy suppressor of the thermosensitive phenotype, the RER2 gene, enco... Yeast journals http://www.medworm.com/rss/comments.php?id=3721391 Thu, 01 Jul 2010 23:00:00 +0100 3721391 http://www.medworm.com/index.php?rid=3842018&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1719 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3842018 Wed, 30 Jun 2010 23:00:00 +0100 3842018 http://www.medworm.com/index.php?rid=3842017&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1768 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3842017 Wed, 30 Jun 2010 23:00:00 +0100 3842017 http://www.medworm.com/index.php?rid=3842016&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1759 Abstract (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3842016 Wed, 30 Jun 2010 23:00:00 +0100 3842016 http://www.medworm.com/index.php?rid=3841997&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1796 (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3841997 Wed, 30 Jun 2010 23:00:00 +0100 3841997 http://www.medworm.com/index.php?rid=3709995&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1799 The concept of Saccharomyces cerevisiae as an emerging opportunistic pathogen is relatively new and it is due to an increasing number of human infections during the past 20 years. There are still few studies addressing the mechanisms of infection of this yeast species. Moreover, little is known about how S. cerevisiae cells sense and respond to the harsh conditions imposed by the host, and whether this response is different between clinical isolates and non-pathogenic strains. In this regard, mitogen-activated protein kinase (MAPK) pathways constitute one of the major mechanisms for controlling transcriptional responses and, in some cases, virulence in fungi. Here we show differences among clinical and non-clinical isolates of S. cerevisiae in the level of activation of the MAPKs Kss1, whi... Yeast journals http://www.medworm.com/rss/comments.php?id=3709995 Tue, 29 Jun 2010 23:00:00 +0100 3709995 http://www.medworm.com/index.php?rid=3709996&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1798 [alpha]1,6-linked mannans are an essential component of the Aspergillus fumigatus galactomannan, which is either GPI-anchored to the plasma membrane or covalently bound to the polysaccharide core of the cell wall. In Saccharomyces cerevisiae, the OCH1 gene encodes an [alpha]1,6-mannosyltransferase that initiates the synthesis of the [alpha]1,6 linked-mannan. In the A. fumigatus genome, four orthologous genes of Saccharomyces cerevisiae ScOCH1 gene were identified. Single deletion and the quadruple deletion mutants (Afoch1-4[Delta]) were constructed in A. fumigatus. No phenotype different from the wild-type strain was observed in all single and the quadruple mutants. The corresponding cDNAs of the AfOCH1-4 A. fumigatus orthologues were expressed in the S. cerevisiae Scoch1[Delta] mutant. Am... Yeast journals http://www.medworm.com/rss/comments.php?id=3709996 Sun, 27 Jun 2010 23:00:00 +0100 3709996 http://www.medworm.com/index.php?rid=3706035&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1795 The cell wall is an essential cellular component for the survival of fungi. The cell wall of the budding yeast Saccharomyces cerevisiae undergoes remodelling during the cell cycle. Evidence is accumulating that there are regulatory mechanisms that link cell wall remodelling and cell cycle progression. Here, we review one such mechanism, known as the 'cell wall integrity checkpoint', which functions to control cell cycle progression in response to cell wall perturbation. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3706035 Sun, 27 Jun 2010 23:00:00 +0100 3706035 http://www.medworm.com/index.php?rid=3679639&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1793 The production of Aspergillus niger glucose oxidase (GOX) and native amylase by the recombinant M. circinelloides KFA199 strain under conditions of dimorphic growth was investigated. The recombinant KFA199 strain was compared to its parental ATCC 1216b strain and a wild-type CBS 232.29 strain under similar morphology-controlled conditions. Cultivation in Vogel's medium supplemented with ergosterol/Tween-80 and sparged with nitrogen gas was most suitable for yeast-like biomass production under anaerobic conditions. Anaerobic growth was characterized by high levels of ethanol formation and linear growth rates of 0.24-0.05/h, indicating metabolic stress. Subsequent to anaerobic growth, cultures were shifted to aerobic conditions to induce aerobic mycelial growth. GOX produced by the recombina... Yeast journals http://www.medworm.com/rss/comments.php?id=3679639 Sun, 20 Jun 2010 23:00:00 +0100 3679639 http://www.medworm.com/index.php?rid=3678423&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1794 The yeast Pseudozyma antarctica produces a large amount of glycolipid biosurfactants known as mannosylerythritol lipids (MELs), which show not only excellent surface-active properties but also versatile biochemical actions. To investigate the biosynthesis of MELs in the yeast, we recently reported expressed sequence tag (EST) analysis and estimated genes expressing under MEL production conditions. Among the genes, a contiguous sequence of 938 bp, PA_004, showed high sequence identity to the gene emt1, encoding an erythritol/mannose transferase of Ustilago maydis, which is essential for MEL biosynthesis. The predicted translation product of the extended PA_004 containing the two introns and a stop codon was aligned with Emt1 of U. maydis. The predicted amino acid sequence shared high identi... Yeast journals http://www.medworm.com/rss/comments.php?id=3678423 Sat, 19 Jun 2010 23:00:00 +0100 3678423 http://www.medworm.com/index.php?rid=3640277&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1790 The glycosylphosphatidylinositol-modified protein Rhd3/Pga29 of the human pathogen Candida albicans belongs to a family of cell wall proteins that are widespread among Candida species but are not found in other fungi. Pga29 is covalently linked to the [beta]-1,3-glucan framework of the cell wall via [beta]-1,6-glucan. It is a small and abundant O-glycosylated protein and requires the protein-O-mannosyl transferase Pmt1 for glycosylation. Furthermore, Pga29 is strongly expressed in yeast cells but is downregulated in hyphae. Removal of the PGA29 gene in C. albicans leads to a significant reduction of cell wall mannan; however, Pga29 does not seem to have a major role in maintaining cell wall integrity. In addition, adhesion capacity and hyphae formation appear normal in pga29 deletion mutan... Yeast journals http://www.medworm.com/rss/comments.php?id=3640277 Mon, 07 Jun 2010 23:00:00 +0100 3640277 http://www.medworm.com/index.php?rid=3624842&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1792 Two mitogen-activated protein kinase (MAPK) pathways, viz. the high-osmolarity glycerol (HOG) and the cell wall integrity (CWI) pathways, regulate stress responses in the yeast Saccharomyces cerevisiae. Whereas the former is mainly involved in adaptation of yeast cells to hyperosmotic stress, the latter is activated under conditions leading to cell wall instability. Although MAPK signalling specificity can be conceived as requiring insulation of the different pathways, it is also becoming clear that the two pathways do not compete with each other but can be positively coordinated to regulate many stress responses. This review highlights our current knowledge about the collaboration between these two MAPK pathways to counteract different kinds of environmental stress. Copyright © 2010 John... Yeast journals http://www.medworm.com/rss/comments.php?id=3624842 Wed, 02 Jun 2010 23:00:00 +0100 3624842 http://www.medworm.com/index.php?rid=3621012&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1787 Recent developments in genomics and proteomics provide evidence that yeast and other fungal cell walls share a common origin. The fibrous component of yeast cell walls usually consists of [beta]-glucan and/or chitin. N-glycosylated proteins form an amorphous, cross-linking matrix as well as fibres on the outer surfaces of the walls. While the enzymes responsible for cross-linking walls into covalent complexes are conserved, the wall-resident proteins have diversified rapidly. These cell wall proteins are usually members of multi-gene families, and paralogues are often subject to gene silencing through epigenetic mechanisms and environmentally induced expression regulation. Comparative studies of protein sequences reveal that there has been fast sequence divergence of the Saccharomyces sexu... Yeast journals http://www.medworm.com/rss/comments.php?id=3621012 Tue, 01 Jun 2010 23:00:00 +0100 3621012 http://www.medworm.com/index.php?rid=3607032&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1791 Saccharomyces cerevisiae has been widely used as a model eukaryotic organism to elucidate the molecular mechanisms that operate upon activation of signalling pathways. For over two decades, many clues to the regulation of mitogen-activated protein kinase (MAPK) pathways have derived from basic research in yeast. Here we review aspects of MAPK pathway fine-tuning, such as the functional implication of feedback loops or regulatory inputs from other pathways, mediated by post-transcriptional modifications on their components. The impact of recent phosphoproteomic approaches in this particular field is also discussed. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3607032 Thu, 27 May 2010 23:00:00 +0100 3607032 http://www.medworm.com/index.php?rid=3607033&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1786 (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3607033 Wed, 26 May 2010 23:00:00 +0100 3607033 http://www.medworm.com/index.php?rid=3595060&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1789 Although the joining of blunt ends in yeast by non-homologous end joining (NHEJ) is reported to be inefficient in comparison to cohesive-end joining (Boulton and Jackson, ), we find that efficiency varies greatly, depending on strain, growth phase and sequence. In particular, the levels of efficiency of recircularization of a plasmid linearized by non-cohesive cleavage is augmented to that of cohesive end joining if the cleavage cut site is flanked by sequences present in the genome. We call this enhancement 'homology-assisted end joining' (HAEJ), which depends on components of the NHEJ repair pathway and, in some cases, on components of the homologous recombination (HR) pathway and on Htl1 a component of the remodels structure of chromatin (RSC) complex. The homologous genome sequences ar... Yeast journals http://www.medworm.com/rss/comments.php?id=3595060 Mon, 24 May 2010 23:00:00 +0100 3595060 http://www.medworm.com/index.php?rid=3595061&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1788 This study focuses on GAS3, a still poorly characterized member of the family. To date, attempts to reveal the glucan elongase activity typical of Gas proteins have been unsuccessful, suggesting that Gas3p is the only inactive member of the family. Here, we compared the mRNA levels of GAS1, GAS3 and GAS5 and demonstrate that GAS3 is the weakest-expressed paralogue in vegetative growth. Moreover, GAS3 mRNA increased during sporulation, showing a bimodal profile typical of the early-middle meiotic genes. GAS3 product was identified as a low-abundance, polydisperse mannoprotein. Loss of Gas3p did not affect growth and sporulation. The overexpression of GAS3, driven by the GAS1 promoter, slightly reduced growth rate in a wild-type strain and led to hyperaccumulation of Gas3p in the membranes a... Yeast journals http://www.medworm.com/rss/comments.php?id=3595061 Sun, 23 May 2010 23:00:00 +0100 3595061 http://www.medworm.com/index.php?rid=3563350&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1785 The integrity of the fungal cell wall is ensured by a signal transduction pathway, the so-called CWI pathway, which has best been studied in the model yeast Saccharomyces cerevisiae. In this context, environmental stress and other perturbations at the cell surface are detected by a small set of plasma membrane-spanning sensors, viz. Wsc1, Wsc2, Wsc3, Mid2 and Mtl1. This review covers the recent advances in sensor structure, sensor mechanics, their cellular distribution and their in vivo functions, obtained from genetic, biochemical, cell biological and biophysical investigations. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3563350 Thu, 13 May 2010 23:00:00 +0100 3563350 http://www.medworm.com/index.php?rid=3563351&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1783 Progress in modern genetics is greatly facilitated by systematic resources that enable rapid and comprehensive analysis. Here we report the creation of a nearly complete systematic low-copy (CEN URA3) library of the Saccharomyces cerevisiae genome that complements existing systematic high-copy libraries. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3563351 Wed, 12 May 2010 23:00:00 +0100 3563351 http://www.medworm.com/index.php?rid=3555530&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1782 We report on the behaviour of several promoter-lacZ reporter plasmids designed to detect cell wall stress transcription through this pathway. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3555530 Tue, 11 May 2010 23:00:00 +0100 3555530 http://www.medworm.com/index.php?rid=3541947&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1771 Yeast cell lysates produced by mechanical glass bead disruption are widely used in a variety of applications, including for the analysis of native function, e.g. protein-protein interaction, enzyme assays and membrane fractionations. Below, we report a striking case of protein denaturation and aggregation that is induced by this lysis protocol. Most of this analysis focuses on the type 1 casein kinase Yck2, which normally tethers to the plasma membrane through C-terminal palmitoylation. Surprisingly, when cells are subjected to glass bead disruption, non-palmitoylated, cytosolic forms of the kinase denature and aggregate, while membrane-associated forms, whether attached through their native palmitoyl tethers or through a variety of artificial membrane-tethering sequences, are wholly prote... Yeast journals http://www.medworm.com/rss/comments.php?id=3541947 Thu, 06 May 2010 23:00:00 +0100 3541947 http://www.medworm.com/index.php?rid=3541949&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1781 In many ascomycetous yeasts, the cell wall is composed of two main types of macromolecules: (a) polysaccharides, with a high content of [beta]-1,6- and [beta]-1,3-linked glucan chains and minor amounts of chitin; and (b) cell wall proteins of different types. Synthesis and maintenance of these macromolecules respond to environmental changes, which are sensed by the cell wall integrity (CWI) signal transduction pathway. We here present a first systematic analysis of the cell wall composition of the milk yeast, Kluyveromyces lactis. Electron microscopic analyses revealed that exponentially growing cells of K. lactis supplied with glucose as a carbon source have a wall thickness of 64 nm, as compared to 105 nm when growing on 3% ethanol. Despite their increased wall thickness, ethanol-grown c... Yeast journals http://www.medworm.com/rss/comments.php?id=3541949 Wed, 05 May 2010 23:00:00 +0100 3541949 http://www.medworm.com/index.php?rid=3541948&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1780 In this study, we analysed 4862 haploid yeast knockout strains of Saccharomyces cerevisiae to identify genes involved in caesium (Cs+) and/or strontium (Sr2+) accumulation. According to this analysis, 212 mutant strains were associated with reproducible altered Cs+ and/or Sr2+ accumulation. These mutants were deficient for a wide range of cellular processes. Among those, the vacuolar function and biogenesis turned out to be crucial for both Cs+ and Sr2+ accumulation. Disruption of the vacuole diminished Cs+ accumulation, whereas Sr2+ enrichment was enhanced. Further analysis with a subset of the identified candidates were undertaken comparing the accumulation of Cs+ and Sr2+ with their essential counterparts potassium (K+) and calcium (Ca2+). Sr2+ and Ca2+ accumulation was highly correlate... Yeast journals http://www.medworm.com/rss/comments.php?id=3541948 Wed, 05 May 2010 23:00:00 +0100 3541948 http://www.medworm.com/index.php?rid=3537625&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1779 The cell division programme included in each cell specifies that, after anaphase, cytokinesis completes the process of producing two cells. With the exception of plant cells, whose peculiarities are out of the scope of this review, in all eukaryotic cells the cleavage furrow that forms late in anaphase bisects the mitotic spindle. Ingression of the furrow and the consequent synthesis of the new membrane are driven by a cortical actomyosin contractile ring (AMR or CAR). The complete contraction of this ring leads to cell separation. While this process is sufficient for cell separation in animal cells, fungal cells are surrounded by a cell wall structure, whose continuity must be maintained to preserve cell integrity during cytokinesis. This maintenance requires the production of a specializ... Yeast journals http://www.medworm.com/rss/comments.php?id=3537625 Wed, 05 May 2010 23:00:00 +0100 3537625 http://www.medworm.com/index.php?rid=3518771&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1769 Diseases caused by Candida species are an increasing problem. Candida species are associated with high overall mortality, due to a variety of virulence factors such as the yeast-to-hyphal switch and proteolytic enzymes. The phenomenon of microbial communication known as quorum sensing also seems to play an important role. The main characteristics of the quorum-sensing molecule E,E-farnesol are well known for C. albicans. The present study focused on two questions. One of them concerned the secretion of E,E-farnesol by C. albicans and involved a close examination of the effect of the medium (serum) and the origin of the isolates used. The second one dealt with the activity of E,E-farnesol in non-C. albicans species, such as C. tropicalis and C. parapsilosis, e.g. its impact on biofilm forma... Yeast journals http://www.medworm.com/rss/comments.php?id=3518771 Thu, 29 Apr 2010 23:00:00 +0100 3518771 http://www.medworm.com/index.php?rid=3510927&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1776 In this report we show that, while these precautions are sufficient for some strains, they are clearly insufficient for others. Specifically, we show that the stability of some proteins, such as Slt2p or Chs4p, but not others, is severely compromised in the rim101[Delta] mutant due to the upregulation of the PRB1 gene, which leads to higher levels of proteinase B activity. This degradation can be almost completely prevented by an overdose of subtilisin-like protease inhibitors, such as PMSF, or by avoiding cell freezing. Growth under other conditions that increase proteinase B activity also leads to the differential degradation of some proteins. Here, analysis of several commercial protease inhibitor cocktails indicated that all of them lacked enough subtilisin-like protease inhibitors to ... Yeast journals http://www.medworm.com/rss/comments.php?id=3510927 Tue, 27 Apr 2010 23:00:00 +0100 3510927 http://www.medworm.com/index.php?rid=3507608&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1778 In this study, we demonstrate that CaPtc2p is a PP2C phosphatase. Surprisingly, in addition to the cytoplasmic localization, CaPtc2p is partially associated with mitochondria in yeast-form and filamentous cells of C. albicans. Expression of CaPTC2 is developmentally regulated during the serum-induced filamentation. Deletion of CaPTC2 renders C. albicans cells sensitive to SDS and azole antifungals, as well as the DNA methylation agent methylmethane sulphonate and the DNA synthesis inhibitor hydroxyurea. Therefore, CaPtc2p might fulfil multiple functions, including the regulation of mitochondrial physiology and checkpoint recovery from DNA damage in C. albicans cells. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3507608 Mon, 26 Apr 2010 23:00:00 +0100 3507608 http://www.medworm.com/index.php?rid=3504549&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1777 In a recent study combining transcriptome analyses of a number of recombinant laboratory and industrial S. cerevisiae strains with improved xylose utilization and their respective control strains, the ORF YLR042c was identified as a downregulated gene and it was shown that the gene deletion improved aerobic growth on xylose in the tested strain background. In the present study, the influence of deleting YLR042c on xylose fermentation was investigated in two different xylose-fermenting strains: TMB3001, which expresses genes from the initial xylose catabolizing pathway, including heterologous xylose reductase (XR) and xylitol dehydrogenase (XDH) and endogenous xylulokinase (XK); and TMB3057, which, in addition to the initial xylose catabolizing pathway, overexpresses the endogenous genes en... Yeast journals http://www.medworm.com/rss/comments.php?id=3504549 Sun, 25 Apr 2010 23:00:00 +0100 3504549 http://www.medworm.com/index.php?rid=3490081&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1773 Although the chemical composition of many fungal cell walls is known, the spatial organization and interactions of the individual macromolecules remain mysterious. In this context, single-cell and single-molecule atomic force microscopy techniques offer new opportunities for probing the surface of fungal cells down to molecular resolution. Recent breakthroughs include the visualization of the structural dynamics of single cells as they grow or interact with drugs, the quantification and nanoscale imaging of cell surface hydrophobicity and the measurement of the molecular elasticity of cell wall polysaccharides and proteins. Here I highlight the advances made by my team in this area during the past 3 years. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3490081 Tue, 20 Apr 2010 23:00:00 +0100 3490081 http://www.medworm.com/index.php?rid=3471275&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1772 The plasma membrane of Saccharomyces cerevisiae contains large microdomains enriched in ergosterol, which house at least nine integral proteins, including proton symporters. The domains adopt a characteristic structure of furrow-like invaginations typically seen in freeze-fracture pictures of fungal cells. Being stable for the time comparable with the cell cycle duration, they might be considered as fixed islands (rafts) in an otherwise fluid yeast plasma membrane. Rapidly moving endocytic marker proteins avoid the microdomains; the domain-accumulated proton symporters consequently show a reduced rate of substrate-induced endocytosis and turnover. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3471275 Wed, 14 Apr 2010 23:00:00 +0100 3471275 http://www.medworm.com/index.php?rid=3471277&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1774 In this work, we developed molecular tools used in standard laboratory yeast strains, such as the cre-loxP system, so that they can be used with natural and industrial prototrophic yeast species. We constructed a new generation of dominant cassettes, with mutated loxP sites (loxLE and lox2272) and selectable drug markers, to create heterothallic strains and auxotrophic mutants without incurring in the risk of generating chromosomal rearrangements. We have shown that our newly developed loxLE-hphNT1-loxRE and lox2272-natNT2-lox2272 gene-disruption cassettes can be present in the yeast genome together with the widely used loxP-marker gene-loxP cassettes without any recombination between the lox sequences. Moreover, we also developed a new phleomycin-resistant Cre-expressing vector (to excise... Yeast journals http://www.medworm.com/rss/comments.php?id=3471277 Tue, 13 Apr 2010 23:00:00 +0100 3471277 http://www.medworm.com/index.php?rid=3471276&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1775 The pathogenic fungus Candida albicans secretes a considerable number of hydrolases and other proteins. In-depth studies of the C. albicans secretome could thus provide new candidates for diagnostic markers and vaccine development. We compared various growth conditions differing in pH, temperature and the presence of the hyphal inducer N-acetylglucosamine. The polypeptide content of the growth media was ca. 0.1-0.2% of the total biomass. Using LC-tandem mass spectrometry, we identified 44 secretory proteins, the transmembrane protein Msb2, six secretory pathway-associated proteins and 28 predicted cytosolic proteins. Many secretory proteins are wall-related, suggesting that their presence in the growth medium is at least partially due to accidental release from the walls. Als3, Csa2, Rbt4,... Yeast journals http://www.medworm.com/rss/comments.php?id=3471276 Tue, 13 Apr 2010 23:00:00 +0100 3471276 http://www.medworm.com/index.php?rid=3382228&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1770 We describe a deterministic model based on ordinary differential equations that describe mRNA translation in Saccharomyces cerevisiae. This model, which was parameterized using published data, was developed to examine the kinetic behaviour of translation initiation factors in response to amino acid availability. The model predicts that the abundance of the eIF1-eIF3-eIF5 complex increases under amino acid starvation conditions, suggesting a possible auxiliary role for these factors in modulating translation initiation in addition to the known mechanisms involving eIF2. Our analyses of the robustness of the mRNA translation model suggest that individual cells within a randomly generated population are sensitive to external perturbations (such as changes in amino acid availability) through G... Yeast journals http://www.medworm.com/rss/comments.php?id=3382228 Fri, 19 Mar 2010 00:00:00 +0100 3382228 http://www.medworm.com/index.php?rid=3377739&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1768 The growth of yeast cells in batches in glucose-based media is a standard condition in most yeast laboratories. Most gene expression experiments are done by taking this condition as a reference. Presumably, cells are in a stable physiological condition that can be easily reproduced in other laboratories. With this assumption, however, it is necessary to consider that the average amount of the mRNAs per cell for most genes does not change during exponential growth. That is to say, there is a steady-state condition for the transcriptome. However, this has not been rigorously demonstrated to date. In this work we take several cell samples during the exponential phase growth to perform a kinetic study using the genomic run-on (GRO) technique, which allows simultaneous measurement of the amount... Yeast journals http://www.medworm.com/rss/comments.php?id=3377739 Thu, 18 Mar 2010 00:00:00 +0100 3377739 http://www.medworm.com/index.php?rid=3358368&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1763 Resident fruit microflora has been the source of biocontrol agents for the control of postharvest decay of fruits and the active ingredient in commercialized biocontrol products. With the exception of grapes and apples, information on the resident microflora of other fruits is only fragmentary, but greater knowledge in this area can be very helpful in developing biocontrol strategies. We characterized the yeast microflora of nectarines ('Croce del Sud') from the early stages of fruit development until harvest. The fruit samples were collected from trees in an unmanaged orchard. The resident fruit microflora was separated from the occasionally deposited microorganisms by discarding initial fruit washings before the final wash, followed by sonication and plating on NYDA medium. The isolated ... Yeast journals http://www.medworm.com/rss/comments.php?id=3358368 Fri, 12 Mar 2010 00:00:00 +0100 3358368 http://www.medworm.com/index.php?rid=3358367&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1765 Heterodimers of acidic proteins P1[alpha]/P2[beta] and P1[beta]/P2[alpha] bind to P0 and are fundamental for the assembly of the ribosomal stalk. However, different inconsistencies are found in the literature regarding additional P protein heterodimer formations and their individual interactions with P0. Using the two-hybrid approach, we have found results that help to clarify these interactions. Thus, we have found that neither P1 nor P2 directly interact with P0 unless the endogenous heterodimer partner is being expressed in the cell. In addition, a P2-free amino end is a requisite in these heterodimers for binding to P0. With regard to the two-hybrid interactions between P1 and P2, the known canonical P1[alpha]-P2[beta] and P1[beta]-P2[alpha] interactions do not depend on either a free ... Yeast journals http://www.medworm.com/rss/comments.php?id=3358367 Fri, 12 Mar 2010 00:00:00 +0100 3358367 http://www.medworm.com/index.php?rid=3349750&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1764 Mitotic catastrophe provokes endopolyploidy, giant cell formation and, eventually, delayed cell death. Mitotic catastrophe is induced by defective cell cycle checkpoints and by some anticancer drugs, ionizing radiation and microtubule-destabilizing agents. RAD2 is a yeast homologue of XPG, which is a human endonuclease involved in nucleotide excision repair. Here we show that Rad2p overexpression alone, in the absence of extrinsic DNA damage, causes cell growth arrest and mitotic catastrophe. Interestingly, Rad2p-induced cell growth arrest is not caused by the catalytic activity of Rad2p but rather by its C-terminal region. Cells growth-arrested by Rad2p induction do not show apoptotic phenotypes and deletion of YCA1, a yeast caspase homologue, does not affect cell growth arrest by Rad2p i... Yeast journals http://www.medworm.com/rss/comments.php?id=3349750 Wed, 10 Mar 2010 00:00:00 +0100 3349750 http://www.medworm.com/index.php?rid=3345975&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1767 Glucose, in the absence of additional nutrients, induces programmed cell death in yeast. This phenomenon is independent of yeast metacaspase (Mca1/Yca1) and of calcineurin, requires ROS production and it is concomitant with loss of cellular K+ and vacuolar collapse. K+ is a key nutrient protecting the cells and this effect depends on the Trk1 uptake system and is associated with reduced ROS production. Mutants with decreased activity of plasma membrane H+-ATPase are more tolerant to glucose-induced cell death and exhibit less ROS production. A triple mutant ena1-4 tok1 nha1, devoid of K+ efflux systems, is more tolerant to both glucose- and H2O2-induced cell death. We hypothesize that ROS production, activated by glucose and H+-ATPase and inhibited by K+ uptake, triggers leakage of K+, a p... Yeast journals http://www.medworm.com/rss/comments.php?id=3345975 Tue, 09 Mar 2010 00:00:00 +0100 3345975 http://www.medworm.com/index.php?rid=3326367&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1766 This study provides new insights into the molecular determinants of target gene specificity of Mxr1p, and the methodology described here can be used for mapping Mxr1p-binding sites in other methanol-inducible promoters of P. pastoris. Copyright © 2010 John Wiley & Sons, Ltd. (Source: Yeast) Yeast journals http://www.medworm.com/rss/comments.php?id=3326367 Wed, 03 Mar 2010 00:00:00 +0100 3326367 http://www.medworm.com/index.php?rid=3275408&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1756 Proteins possessing a C-terminal CaaX motif, such as the Ras GTPases, undergo extensive post-translational modification that includes attachment of an isoprenoid lipid, proteolytic processing and carboxylmethylation. Inhibition of the enzymes involved in these processes is considered a cancer-therapeutic strategy. We previously identified nine in vitro inhibitors of the yeast CaaX protease Rce1p in a chemical library screen (Manandhar et al., ). Here, we demonstrate that these agents disrupt the normal plasma membrane distribution of yeast GFP-Ras reporters in a manner that pharmacologically phenocopies effects observed upon genetic loss of CaaX protease function. Consistent with Rce1p being the in vivo target of the inhibitors, we observe that compound-induced delocalization is suppressed... Yeast journals http://www.medworm.com/rss/comments.php?id=3275408 Tue, 16 Feb 2010 00:00:00 +0100 3275408 http://www.medworm.com/index.php?rid=3275407&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1757 The basic helix-loop-helix (bHLH) proteins comprise a eukaryotic transcription factor family involved in multiple biological processes. They have the ability to form multiple dimer combinations and most of them also bind a 6 bp site (E-box) with limited specificity. These properties make them ideal for combinatorial regulation of gene expression. The Saccharomyces cerevisiae CIT2 gene, which encodes citrate synthase, was previously known to be induced by the bHLH proteins Rtg1p and Rtg3p in response to mitochondrial damage. Rtg1p-Rtg3p dimers bind two R-boxes (modified E-boxes) in the CIT2 promoter. The current study tested the ability of all nine S. cerevisiae bHLH proteins to regulate the CIT2 gene. The results showed that expression of CIT2-lacZ reporter was induced in a [rho]0 strain b... Yeast journals http://www.medworm.com/rss/comments.php?id=3275407 Tue, 16 Feb 2010 00:00:00 +0100 3275407 http://www.medworm.com/index.php?rid=3275406&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1762 In this study, we isolated and characterized a Yarrowia lipolytica HAC1 (YlHAC1) encoding a basic-leucine zipper transcription factor. The null mutant strain of YlHAC1 ([Delta]Ylhac1) displayed a significantly increased sensitivity to dithiothreitol (DTT) and tunicamycin (TM), along with a defect in hyphal growth, suggesting the essential function of YlHAC1 in UPR. The unconventional splicing of YlHAC1 mRNA occurred under the UPR conditions induced by DTT or TM treatment. Unlike S. cerevisiae HAC1 mRNA with an intron of 252 nt, YlHAC1 mRNA was shown to harbour a short intron of length 29 nt. The YlHAC1 mRNA harboured the nucleotides CAG, conserved at the intron borders in the filamentous fungi hac1/hacA and mammalian XBP1, as well as a conserved bipartite element within the 3[prime] untran... Yeast journals http://www.medworm.com/rss/comments.php?id=3275406 Tue, 16 Feb 2010 00:00:00 +0100 3275406 http://www.medworm.com/index.php?rid=3275405&cid=s_33786_67_f&fid=33786&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fyea.1758 Here we present a set of resources (bacterial expression plasmids and antibodies) for the interrogation of proteins involved in yeast MAPK signalling. We constructed bacterial protein expression plasmids for 25 proteins involved in MAPK signalling in budding yeast. From these constructs we expressed and purified proteins and generated rabbit polyclonal antibodies against 13 proteins in the pheromone MAPK pathway. We verified the specificity of the antibodies and employed them to follow pathway proteins in cells stimulated with pheromone. We show that these reagents can be used to detect pheromone-induced post-translational modifications and changes in the oligomeric state of pathway proteins. In addition to recognizing their target proteins in Saccharomyces cerevisiae, these antibodies all... Yeast journals http://www.medworm.com/rss/comments.php?id=3275405 Tue, 16 Feb 2010 00:00:00 +0100 3275405