Project description:When challenged with osmotic shock, S. cerevisiae induces hundreds of genes, despite a global reduction in transcriptional capacity. The mechanisms that regulate this rapid reallocation of transcriptional resources are not known. Here we show that redistribution of RNA Pol II upon stress requires the stress-responsive MAP kinase Hog1. We find that Hog1 and RNA Pol II co-localize to open reading frames that bypass global transcriptional repression, and that these targets are specified by two osmotic stress-responsive transcription factors. The combination of reduced global transcription with a gene-specific override mechanism allows cells to rapidly switch their transcriptional program in response to stress.
Project description:When challenged with osmotic shock, S. cerevisiae induces hundreds of genes, despite a global reduction in transcriptional capacity. The mechanisms that regulate this rapid reallocation of transcriptional resources are not known. Here we show that redistribution of RNA Pol II upon stress requires the stress-responsive MAP kinase Hog1. We find that Hog1 and RNA Pol II co-localize to open reading frames that bypass global transcriptional repression, and that these targets are specified by two osmotic stress-responsive transcription factors. The combination of reduced global transcription with a gene-specific override mechanism allows cells to rapidly switch their transcriptional program in response to stress. ChIP-sequencing of S. cervisiae RNA Pol II, Hog1, Sko1 and Hot1 Processed data file descriptions: ORFcounts.txt: table of summed ChIP-seq reads that align to each ORF (normalized by reads per kilobase per million) promoter_counts.txt: table of summed ChIP-seq reads that align to each promoter (1kb upstream, normalized by reads per kilobase per million) downstream_counts.txt: table of summed ChIP-seq reads that align 3' regions (50-500 bp downstream, normalized by reads per kilobase per million) Sko1_peak_list.txt: table of peaks found by PeakSeq Hot1_peak_list.txt: table of peaks found by PeakSeq
Project description:Cells are subjected to dramatic changes on gene expression upon environmental changes. Stress causes a general down-regulation of gene expression together with the induction of a set of stress-responsive genes. Genome wide localisation studies showed major changes on Pol II localisation towards stress-responsive genes in contrast to housekeeping genes. Pol II relocalisation requires of the Hog1 SAPK, which also associates at stress-responsive loci. Chromatin structure was not significantly altered upon stress except for those genes that displayed Hog1 association. Together, Hog1 serves to bypass the general down-regulation of gene expression by targeting RNA Pol II machinery and inducing chromatin remodeling at stress-responsive loci. Hog1 and Pol II ChIP-Seq and Mnase-Seq experiments in both strains WT and Hog1 mutant, for 2 conditions: Exposed and not exposed to osmostress
Project description:Cells are subjected to dramatic changes on gene expression upon environmental changes. Stress causes a general down-regulation of gene expression together with the induction of a set of stress-responsive genes. Genome wide localisation studies showed major changes on Pol II localisation towards stress-responsive genes in contrast to housekeeping genes. Pol II relocalisation requires of the Hog1 SAPK, which also associates at stress-responsive loci. Chromatin structure was not significantly altered upon stress except for those genes that displayed Hog1 association. Together, Hog1 serves to bypass the general down-regulation of gene expression by targeting RNA Pol II machinery and inducing chromatin remodeling at stress-responsive loci.
Project description:RNA polymerase II (Pol II) is generally paused at promoter-proximal regions in most metazoans, and based on in vitro studies, this function has been attributed to the negative elongation factor (NELF). Here, we show that upon rapid depletion of NELF, Pol II fails to be released into gene bodies, stopping instead around the +1 nucleosomal dyad-associated region. The transition to the 2nd pause region is independent of positive transcription elongation factor P-TEFb. During the heat shock response, Pol II is rapidly released from pausing at heat shock induced genes, while most genes are paused and transcriptionally downregulated during the heat shock response. We find that both aspects of the heat shock response remain intact upon NELF loss. We find that NELF depletion results in global loss of cap-binding complex from chromatin without global reduction of nascent transcript 5’ cap stability. Thus, our studies implicate NELF functioning in early elongation complexes distinct from Pol II pause-release.
Project description:mRNA amount (RA) and Transcription rate (TR) analysis of W303-1a (wt) and hog1 mutant yeast strains growing in exponential phase in YPD subjected to osmotic stress This SuperSeries is composed of the following subset Series: GSE13096: Transcription rate analysis of wild type strain subjected to osmotic stress GSE13097: mRNA amount analysis of wild type strain subjected to osmotic stress GSE13098: Transcription rate analysis of W303 hog1 mutant strain subjected to osmotic stress GSE13099: mRNA amount analysis of W303 hog1 mutant strain subjected to osmotic stress Refer to individual Series Transcriptomic and transcription rate analysis by means of GRO of three independent replicates the yeast strain growing in exponential phase. Each time point replicate has been hybridized on a different macroarray (F11-F24). A single DNA genomic hybridization from the same labeling reaction was done on the same microarrays for normalization.
Project description:In our previous work, we had found that Saccharomyces cerevisiae needs of the Hog1 and Slt2 proteins to growth in a low pH environment caused by sulfuric acid, one of the stress factors during the process of ethanol production. Then was performed the gene-wide expression analysis in the hog1∆ and slt2∆ mutants in order to reveal the function of the Hog1p and Slt2p MAP Kinases in the regulation of S. cerevisiae global gene expression upon stress by sulfuric acid.