Project description:This SuperSeries is composed of the following subset Series: GSE30897: Nucleosome occupancy in yeast BY4741and a strain lacking MSN2 and MSN4 responding to 20 min treatment with 0.4mM H2O2 GSE30898: Msn2p occupancy dynamics in yeast BY4741 responding to 0.4mM H2O2 over time (0-60 min) GSE30899: Gene expression dynamics in yeast BY4741 and a strain lacking MSN2 and MSN4 responding to 0.4mM H2O2 over time (0-60min) GSE30900: Nucleosome occupancy dynamics in yeast BY4741 responding to 0.4mM H2O2 over time (0-60 min) Refer to individual Series
Project description:Numerous factors have been implicated in regulating gene expression changes, including changes to nucleosome occupancy. Here we followed dynamic changes to nucleosome occupancy, gene expression and DNA binding of the transcription factor Msn2p genome-wide in yeast cells responding to hydrogen peroxide and reveal new relationships between regulators of stress-dependent gene expression in yeast. Nucleosome occupancy was measured in the S288c derivative BY4741 and a strain lacking MSN2 and MSN4. Nucleosomes were isolated from unstressed yeast and yeast treated for 20 min with 0.4mM H2O2. Nucleosomal samples were compared in a 2-color, competitive hybridization to sheared genomic DNA.
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:Numerous factors have been implicated in regulating gene expression changes, including changes to nucleosome occupancy. Here we followed dynamic changes to nucleosome occupancy, gene expression and DNA binding of the transcription factor Msn2p genome-wide in yeast cells responding to hydrogen peroxide and reveal new relationships between regulators of stress-dependent gene expression in yeast. Gene expression was measured in response to 0.4mM H2O2 in the S288c derivative BY4741 in wild-type cells and cells lacking MSN2 and MSN4. A single replicate of a time course spanning from 4 to 60 minutes after treatment in each cell type. An additional 3 repliactes were collected from cells 30 minutes after treatment.
Project description:Exposure of Saccharomyces cerevisiae to alkaline pH represents a stress condition that generates a compensatory reaction. Here we examine a possible role of the protein kinase-A (PKA) pathway in this response. The phenotypic analysis reveals that mutations that activate the PKA pathway (ira1 ira2, bcy1) tend to cause sensitivity to alkaline pH, whereas its deactivation develops tolerance to this stress. We observe that alkalinization causes a transient decrease in cAMP, the main regulator of the pathway. Alkaline pH causes rapid nuclear localization of the PKA-regulated Msn2 transcription factor which, together with Msn4, mediates a general stress response by binding to STRE sequences in many promoters. Consequently, a synthetic STRE-LacZ reporter shows a rapid induction in response to alkaline stress. An msn2 msn4 mutant is sensitive to alkaline pH, and transcriptomic analysis reveals that after 10 minutes of alkaline stress, the expression of many induced genes (47%) depends, at least in part, on the presence of Msn2 and Msn4. Taken together, these results demonstrate that inhibition of the PKA pathway by alkaline pH represents a substantial part of the adaptive response to this kind of stress and that this response involves Msn2/Msn4-mediated gene remodeling. However, the relevance of attenuation of PKA in high pH tolerance is not restricted to regulation of Msn2 function. Eight samples were analyzed: WT and the MCY5278 mutant strain, lacking both Msn2 and Msn4, in the presence of 20 mM KOH (pH 8) and in the presence of 20 mM KCl (non-induced conditions) for 10 and 30 min of stress. 2 biological replicates were analyzed for each condition, and dye-swapping was carried out for each comparison of samples. We compared the expression profiles of: 1) WT +KOH vs. WT +KCl after 10 min 2) msn2 msn4 mutant +KOH vs. msn2 msn4 +KCl after 10 min 3)WT +KOH vs. WT +KCl after 30 min 4) msn2 msn4 mutant +KOH vs. msn2 msn4 +KCl after 30 min Total number of chips analyzed: 16.
Project description:The aim of this experiment was to determine, using MNAse-Seq, how nucleosomes get remodeled during an Msn2 activation timecourse genome-wide. Diploid strain EY2807/ASH79 with genotype TPK1M164G TPK2M147G TPK3M165G msn4::TRP1/LEU2 MSN2-mCherry NHP6a-iRFP::kanMX was used. This strain is PKAas, so upon addition of the inhibitor 1-NM-PP1, Msn2 translocates to the nucleus and activates gene expression. In this experiment, the diploid strain was exposed to 3 uM 1-NM-PP1 for 0, 5, 10, 20 and 40 min and nucleosome positions determined using by crosslinking, MNAse treatment, nucleosomal DNA purification and paired-end high-throughput sequencing (Illumina). Results from transcriptional profiling of yeast with or without Msn2 expression were also deposited at ArrayExpress under accession number E-MTAB-1945 ( https://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-1945/ ).
Project description:Transcriptional profiling of Msn2 regulated genes. Both strains are PKAas (TPK1M164G TPK2M147G TPK3M165G) and msn4-delta. One strain has Msn2 C-terminally tagged with mCherry and the other strain is msn2-delta. In this experiment, both strains were exposed to 3 uM 1-NM-PP1, which leads to Msn2 nuclear localization, for 0, 10, 20 and 40 min. The goal was to determine the genes that show a strong upregulation in the presence of Msn2, but no expression change in the absence of Msn2.