Project description:Hog1 bypasses stress-mediated downregulation of transcription by PolII redistribution and chromatin remodeling Keyword: genetic modification Three independent 200 ml cultures of wild-type strain were grown to mid-log phase in YPD rich medium at 30ºC
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: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:Genomic analysis has revealed the existence of a large number of long non-coding RNAs (lncRNAs) in a variety of organisms, including yeast. lncRNAs might have several biological functions during normal cell growth and development. Cells are subject to dramatic changes of gene expression in response to environmental changes. Using whole-genome tiling arrays, we found that a set of lncRNAs are induced specifically by the Hog1 stress-activated protein kinase (SAPK) in response to stress. Cdc28 kinase controls the cell cycle in yeast and there is a stress-induced lncRNA in the antisense orientation in CDC28, which permits Hog1 and RSC to induce CDC28 gene expression by remodeling the +1 nucleosome. Increased levels of Cdc28 mediate a more efficient cell cycle re-entry after stress. Therefore, Hog1 mediates changes on the level of Cdc28 protein by induction of a specific lncRNA.
Project description:In budding yeast, this signaling pathway— the high-osmolarity glycerol (HOG) response —culminates in dual phosphorylation and nuclear translocation of the MAPK, Hog1 (ortholog of mammalian p38/SAPK). Induction of at least 50 genes requires nuclear Hog1, implying that transcriptional up-regulation is necessary to cope with hyperosmotic stress. Contrary to this expectation, we found that cells lacking the karyopherin (Nmd5) required for Hog1 nuclear import or in which Hog1 was permanently anchored at the plasma membrane(HOG1-CCAAX) (or both) withstood hyperosmotic challenge by three different solutes (1 M sorbitol, KCl or NaCl). In cells where activated Hog1 is excluded from the nucleus, there was little change in transcriptional program after exposure to hyperosmotic shock (comparable to hog1∆ cells), as judged by examining several diagnostic mRNAs and by global transcript measurements using microarrays. Systematic genetic analysis ruled out the need for any transcription factor known to be influenced by Hog1 (Hot1, Msn2, Msn4, Sko1 and Smp1). Keywords: Time course of stress response gene expression array