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:A systematic approach allowing the identification of the molecular way of action of novel potential drugs still represents the golden-tool for drug-discovery researchers. 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 compared to the well-known antifungal, ketoconazole. 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 as well as in pathogenic fungi further demonstrated the reliability of the multi-sided approach and the novelty of the targets and mode of action of the new class of molecules studied that thus represent a valuable source of novel antifungals.
Project description:Transcriptomic study to characterize the interaction of the Penicillium expansum antifungal protein PeAfpA with the the model yeast Saccharomyces cerevisiae. For this, the transcriptome of S. cerevisiae BY4741 strain was compared among samples treated with increasing concentrations of PeAfpA.
Project description:Honokiol (HNK), one of the main medicinal components in Magnolia officinalis, possesses antimicrobial activity against a variety of pathogenic bacteria and fungi.S. cerevisiae is a model eukaryote used for investigating the cellular and molecular mechanisms of anti-fungal drugs. To explore the molecular mechanism of its anti-fungal activity, we determined the effects of HNK on the mRNA expression profile of Saccharomyces cerevisiae using a DNA microarray approach.
Project description:LPS was used as a stressor to stimulate the model organism Saccharomyces cerevisiae. To detect extracellular metabolic information of VOCs. To provide a molecular basis for cellular metabolism of VOCs by proteome.
Project description:6-Nonadecynoic acid (6-NDA), a plant-derived acetylenic acid, exhibits strong inhibitory activity against the human fungal pathogens Candida albicans, Aspergillus fumigatus, and Trichophyton mentagrophytes. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model organism Saccharomyces cerevisiae to investigate the mechanism of action of this compound. 6-NDA elicited a transcriptome response indicative of fatty acid stress, altering the expression of genes known to be affected when yeast cells are grown in the presence of oleate. Mutants of S. cerevisiae lacking transcription factors that regulate fatty acid beta-oxidation showed increased sensitivity to 6-NDA. Fatty acid profile analysis indicated that 6-NDA inhibited the formation of fatty acids longer than 14 carbons in length. In addition, the growth inhibitory effect of 6-NDA was rescued in the presence of exogenously supplied oleate. To investigate the response of a pathogenic fungal species to 6-NDA, transcriptional profiling and biochemical analyses were also conducted in C. albicans. The transcriptional response and fatty acid profile of C. albicans were comparable to those obtained in S. cerevisiae, and the rescue of growth inhibition with exogenous oleate was also observed in C. albicans. In addition, 6-NDA enhanced the potency of the antifungal drug fluconazole in a fluconazole-resistant clinical isolate of C. albicans. Collectively, our results indicate that the antifungal activity of 6-NDA is mediated by a disruption in fatty acid homeostasis, and that this compound has potential utility in combination therapy in the treatment of drug-resistant fungal infections.
Project description:Pre-mRNA splicing is vital for the proper function and regulation of eukaryotic gene expression. Saccharomyces cerevisiae has been used as a model organism for studies of RNA splicing because of the striking conservation of the spliceosome and its catalytic activity. Nonetheless, there are relatively few annotated alternative splice forms, particularly when compared to higher eukaryotes. Here, we describe a method to combine large scale RNA sequencing data to accurately discover novel splice isoforms in Saccharomyces cerevisiae. Using our method, we find extensive evidence for novel splicing of annotated intron-containing genes as well as genes without previously annotated introns and splicing of transcripts that are antisense to annotated genes. By incorporating several mutant strains at varied temperatures, we find conditions which lead to differences in alternative splice form usage. Despite this, every class and category of alternative splicing we find in our datasets is found, often at lower frequency, in wildtype cells under normal growth conditions. Together, these findings show that there is widespread splicing in Saccharomyces cerevisiae.
Project description:Plakortide F acid (PFA), a marine-derived polyketide endoperoxide, exhibits strong inhibitory activity against the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model organism Saccharomyces cerevisiae, to investigate the mechanism of action of this compound. PFA elicited a transcriptome response indicative of a Ca2+ imbalance, affecting the expression of genes known to be responsive to altered cellular calcium levels. Several additional lines of evidence obtained supported a role for Ca2+ in PFA's activity. First, mutants lacking calcineurin and various Ca2+ transporters including pumps (Pmr1 and Pmc1) and channels (Cch1 and Mid1) showed increased sensitivity to PFA. In addition, the calcineurin inhibitors FK506 and cyclosporine A strongly enhanced PFA activity in wild-type cells. Furthermore, PFA activated the transcription of a lacZ reporter driven by the calcineurin-dependent response element. Finally, elemental analysis indicated a significant increase in intracellular calcium levels in PFA-treated cells. Collectively, our results demonstrate that PFA mediates its antifungal activity by perturbing Ca2+ homeostasis, thus representing a potentially novel mechanism distinct from that of currently used antifungal agents. DNA microarray analysis of gene expression response to the antifungal compound plakortide F acid in yeast