Project description:The ability to survive stress conditions is important for every living cell. Some stresses can affect not only current cell well-being, but may have far-reaching consequences. Uncurbed oxidative stress can cause DNA damage and the decrease in cell survival and/or increase in mutation rate. Some substances generating oxidative damage in the cell act mainly on DNA. Radiomimetic zeocin is a chemoenzyme that causes oxidative damage in DNA, inducing predominantly single or double strand breaks. Such lesions can subsequently lead to chromosomal rearrangements in genomic DNA, especially in diploid cells in which each sequence has its duplicate in the homologous chromosome. In a global screen for mutants oversensitive to zeocin, we selected 136 genes whose deletion causes the decrease in survival of diploid Saccharomyces cerevisiae cells exposed to this compound. The screen revealed numerous genes connected with stress response, including response to DNA damage stimulus; DNA repair genes, especially connected with homologous recombination and telomere maintenance; genes involved in cell cycle progression, chiefly in control of cell divisions checkpoints, both meiotic and mitotic; and genes involved in remodeling of chromatin. Notably, our screen also demonstrated the involvement of vesicular trafficking system in cell protection against DNA damage. Presented data imply vesicular system in various pathways of cell protection from zeocin-dependent damage, including the role in detoxification and probably more direct role in genome maintenance processes. We show, that cells with vesicular trafficking dysfunction are unable to repair zeocin induced damage, accumulate Rad52 foci and frequently possess an atypical DNA content. Therefore, we postulate that functional vesicular trafficking is crucial for sustaining integral genome. We believe that numerous new genes implicated in genome maintenance after genotoxic oxidative stress, together with newly discovered vesicular trafficking link to genome integrity, will help revealing novel molecular processes involved in the genome stability of diploid cells.
Project description:Industrial bioethanol production may involve a low pH environment,improving the tolerance of S. cerevisiae to a low pH environment caused by inorganic acids may be of industrial importance to control bacterial contamination, increase ethanol yield and reduce production cost. Through analysis the transcriptomic data of Saccharomyces cerevisiae with different ploidy under low pH stress, we hope to find the tolerance mechanism of Saccharomyces cerevisiae to low pH.
Project description:Saccharomyces cerevisiae is an excellent microorganism for industrial succinic acid production, but high succinic acid concentration will inhibit the growth of Saccharomyces cerevisiae then reduce the production of succinic acid. Through analysis the transcriptomic data of Saccharomyces cerevisiae with different genetic backgrounds under different succinic acid stress, we hope to find the response mechanism of Saccharomyces cerevisiae to succinic acid.
Project description:This study explores the connection between changes in gene expression and the genes that determine strain survival during suspension culture, using the model eukaryotic organism, Saccharomyces cerevisiae. The Saccharomyces cerevisiae homozygous diploid deletion pool, and the BY4743 parental strain were grown for 18 hours in a rotating wall vessel, a suspension culture device optimized to minimize the delivered shear. In addition to the reduced shear conditions, the rotating wall vessels were also placed in a static position or in a shaker in order to change the amount of shear stress on the cells. Keywords: shear stress, time course
Project description:During fermentation Saccharomyces yeast produces various aroma-active metabolites determining the different characteristics of aroma and taste in fermented beverages. Amino acid utilization by yeast during brewer´s wort fermentation is seen as linked to flavour profile. To better understand the relationship between the biosynthesis of aroma relevant metabolites and the importance of amino acids, DNA microarrays were performed for Saccharomyces cerevisiae strain S81 and Saccharomyces pastorianus var. carlsbergensis strain S23, respectively. Thereby, changes in transcription of genes were measured, which are associated with amino acid assimilation and its derived aroma-active compounds during fermentation.
Project description:The conserved Saccharomyces cerevisiae kinase/ATPase Rio1 downregulates rDNA transcription to promote rDNA stability and segregation. To uncover additional roles in transcriptional regulation beyond the rDNA locus we defined the global Rio1 transcriptiome. By NGS we identify 818 differentially expressed genes that are under the transcriptional control of Rio1.
Project description:In response to limited nitrogen and abundant carbon sources, diploid Saccharomyces cerevisiae strains undergo a filamentous transition in cell growth as part of pseudohyphal differentiation. Use of the disaccharide maltose as the principal carbon source, in contrast to the preferred nutrient monosaccharide glucose, has been shown to induce a hyper-filamentous growth phenotype in a strain deficient for GPA2 which codes for a Galpha protein component that interacts with the glucose-sensing receptor Gpr1p to regulate filamentous growth. In this report, we compare the global transcript and proteomic profiles of wild-type and Gpa2p deficient diploid yeast strains grown on both rich and nitrogen starved maltose media. We find that deletion of GPA2 results in significantly different transcript and protein profiles when switching from rich to nitrogen starvation media. The results are discussed with a focus on the genes associated with carbon utilization, or regulation thereof, and a model for the contribution of carbon sensing/metabolism-based signal transduction to pseudohyphal differentiation is proposed. Keywords: Saccharomyces cerevisiae, nitrogen starvation, maltose, pseudohyphal differentiation, yeast, expression profiling
Project description:We determined nucleosome positions genome-wide in diploid Saccharomyces species undergoing early stages of synchronous meiosis. This study sought to assess if meiotic DNA double-strand break formation occurred preferentially in promoter nucleosome-depleted regions in other Saccharomyces species, as it does in S. cerevisiae SK1 (Pan et al. 2011 Cell 144:719-731).