Project description:A systematic approach allowing the identification of the molecular way-of-action of novel potential drugs represents the golden-tool for drug-discovery. While high-throughput screening technologies of large libraries is now well established, the assessment of the drug targets and mechanism of action is still under development. Taking advantage of the yeast model Saccharomyces cerevisiae, we herein applied BarSeq, a Next Generation Sequencing-based method to the analysis of both haploinsufficiency and homozygous fitness effects of a novel antifungal drug ('089') compared to the well-known antifungal ketoconazole. '089' was a novel compound identified in during a screen for antifungal drugs, as it was showing fungicidal effects, and able to affect the yeast fitness at the mitochondrial level (Stefanini et al., 2010. (Dissection of the Effects of Small Bicyclic Peptidomimetics on a Panel of Saccharomyces cerevisiae Mutants;.J Biol Chem, 285: 23477-23485.) Integrative bioinformatic analysis of BarSeq, whole genome expression analysis and classical biological assays identified the target and cell pathways affected by the novel antifungal. Confirmation of the effects observed in the yeast model and in pathogenic fungi further demonstrated the reliability of the multi-sided approach and the novelty of the targets and way-of-action of the new class of molecules studied representing a valuable source of novel antifungals.
Project description:The analysis allow to delve into the molecular activity of the molecule 089, wich induced a growth decrease on various yeast strains. Yeast strains selected are knock-out mutants in genes involved in MDR (BY4742Δerg6, BY4742Δsnq2) and the parental strain (BY4742).
Project description:Telomere chromatin structure is pivotal for maintaining genome stability by regulating the binding of telomere-associated proteins and inhibition of a DNA damage response. In yeast, the silent information regulator (Sir) proteins bind to terminal telomeric repeats and to subtelomeric X-elements resulting in histone deacetylation and transcriptional silencing. Herein, we show that sir2 mutant strains display a very specific loss of a nucleosome residing in the X-element. Most yeast telomeres contain an X-element and the nucleosome occupancy defect in sir2 mutants is remarkably consistent between different telomeres.
Project description:Saccharomyces cerevisiae has been used as a secretion host for production of various products, including pharmaceuticals. However, few antibody molecules have been functionally expressed in S. cerevisiae due to the incompatible surface glycosylation. Our laboratory previously isolated a group of yeast mutant strains with different α-amylase secretory capacities, and these evolved strains have showed advantages for production of some heterologous proteins. However, it is not known whether these secretory strains are generally suitable for pharmaceutical protein production. Here, three non-glycosylated antibody fragments with different configurations (Ran-Fab fragment Ranibizumab, Pex-the scFv peptide Pexelizumab, and Nan-a single V-type domain) were successfully expressed and secreted in three background strains with different secretory capacities, including HA (wild type), MA (evolved strain), and LA (evolved strain). However, the secretion of Ran and Nan were positively correlated with the strains’ secretory capacity, while Pex was most efficiently secreted in the parental strain. Therefore, transcriptional analysis was performed to explore the fundamental changes triggered by the expression of the different pharmaceutical proteins in these selected yeast strains.
Project description:The analysis allow to delve into the molecular activity of the molecule 089, wich induced a growth decrease on various yeast strains. Yeast strains selected are knock-out mutants in genes involved in MDR (BY4742Îerg6, BY4742Îsnq2) and the parental strain (BY4742). Six samples analyzed, two biological replicatesfor each yeast strain, the referenze samples is the treatment with 089 of the parental strain, BY4742.
Project description:Samples GSM206658-GSM206693: Acquired Stress resistance in S. cerevisiae: NaCl primary and H2O2 secondary Transcriptional timecourses of yeast cells exposed to 0.7M NaCl alone, 0.5mM H2O2 alone, or 0.5mM H2O2 following 0.7M NaCl, all compared to an unstressed sample. Repeated using msn2∆ strain. Samples GSM291156-GSM291196: Transcriptional response to stress in strains lacking MSN2 and/or MSN4 Transcriptional timecourses of yeast cells (WT, msn2∆, msn4∆, or msn2∆msn4∆) exposed to 0.7M NaCl for 45 minutes or 30-37˚C Heat Shift for 15 min compared to an unstressed sample of the same strain. Keywords: Stress Response
Project description:Effect of FLO8 or MSS11 deletion and -overexpression on yeast transcript profiles compared to wild type in laboratory yeast strains Σ1278b and S288c.