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:The accumulation of unfolded proteins in the lumen of the endoplasmic reticulum (ER) causes stress and induces the unfolded protein response (UPR) which is characterised in part by the transcriptional induction of genes involved in assisting protein folding. Translational responses to ER stress have been less well described and here we report on a genome-wide analysis of translational regulation in the response to the ER stress-inducing agent dithiothreitol (DTT) in Saccharomyces cerevisiae. Although the observed polysome profiles were similar under control and ER stress conditions microarray analysis identified transcipt-specific translational regulation. Genes with functions in ribosomal biogenesis and assembly were translationally repressed under ER stress. In contrast mRNAs for known UPR genes, including the UPR transcription factor HAC1, the ER-oxidoreductase ERO1 and the ER-associated protein degradation (ERAD) gene DER1 were enriched in polysomal fractions under ER stress conditions. In addition, we show that splicing of HAC1 mRNA is required for efficient ribosomal loading and that Gcn2p is required for normal HAC1 splicing, so shedding light on the role of this protein kinase in the UPR pathway. Keywords: stress response, translational analysis
Project description:The aim of this study was to determine how nitrogen repletion affected the genomic cell response of a Saccharomyces cerevisiae wine yeast strain, in particular within the first hour following relief from nutrient starvation. We found almost 4000 genes induced or repressed sometimes within minutes of nutrient changes. Some of the transcriptional responses to nitrogen depended on the TOR pathway which control positively ribosomal protein genes, amino acid and purine biosynthesis or amino acid permease genes and negatively stress-response genes, RTG specific TCA cycle genes and NCR sensitive genes. Some unexpected transcriptional responses concerned all the glycolytic genes, the starch and glucose metabolism and citrate cycle related genes which were down-regulated, as well as genes from the lipid metabolism.
