Widespread Misinterpretable ChIP-seq Bias in Yeast
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ABSTRACT: We report widespread ChIP-seq bias at highly expressed genes in yeast that could lead to misinterpretation ChIP-seq for multiple transcription or chromatin-associated factors and negative controls
Project description:We report the genome-wide Chd1 co-occupancy with early transcription elongation factors ChIP-seq for Chd1 and elongating RNA polymerase II
Project description:Transcript level changes in transcription factor mutants after rapamycin treatment, compared to the wild-type strain. This data set accompanies the study "Widespread Misinterpretable ChIP-seq Bias in Yeast" (GSE51251) Four separate wild-type cultures of yeast were grown, and each culture was split into two. Then, one was treated with DMSO and the other one was treated with rapamycin. For transcription factor mutants, two separate cultures were grown, and rapamycin was treated in the same way as treated to the wild type. Total RNA was recovered from each culture, then labeled oligo was prepared following NimbleGene standard protocol. Each chip measures the expression levels of 5,777 genes from yeast.
Project description:We report nucleosome poisitioning under pertubation conditions such as heat shock, CHD1 deletion, and SET2 deletion Mono-nucleosome DNA was prepared from wild type strain under normal or heat shock conditions, or CHD1 or SET2 deletion strain. The mono-nucleosome DNA was mapped.
Project description:Proteins regulate gene expression by controlling mRNA biogenesis, localization, translation and decay. Identifying the composition, diversity and function of mRNPs (mRNA protein complexes) is essential to understanding these processes. In a global survey of S. cerevisiae mRNA binding proteins we identified 120 proteins that cross-link to mRNA, including 66 new mRNA binding proteins. These include kinases, RNA modification enzymes, metabolic enzymes, and tRNA and rRNA metabolism factors. These proteins show dynamic subcellular localization during stress, including assembly into stress granules and P-bodies (Processing-bodies). CLIP (cross-linking and immunoprecipitation) analyses of the P-body components Pat1, Lsm1, Dhh1 and Sbp1 identified sites of interaction on specific mRNAs revealing positional binding preferences and co-assembly preferences. Taken together, this work defines the major yeast mRNP proteins, reveals widespread changes in their subcellular location during stress, and begins to define assembly rules for P-body mRNPs. CLIP-seq analysis of Dhh1, Lsm1, Pat1 and Sbp1
Project description:Snt2 is a yeast chromatin-interacting protein whose function has not been well characterized, that was recently shown to associate with Ecm5 and the Rpd3 deacetylase. Using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq), we show that in response to H2O2, Snt2 and Ecm5 colocalize to promoters of genes involved in various aspects of the environmental stress response. By integrating these ChIP-seq results with expression analysis, we identify a key set of target genes that require Snt2 for proper expression after H2O2 stress. Finally, by mapping Snt2 and Ecm5 localization before and after rapamycin treatment, we identify a subset of H2O2-specific Snt2 and Ecm5 target promoters that are also targeted in response to rapamycin. Our results establish a function for Snt2 in regulating transcriptional changes in response to oxidative stress, and suggest Snt2 may have a role in additional stress pathways. Crosslinking ChIP analysis to identify sites of Snt2 or Ecm5 genomic localization before, 0.5 hours after, or 4 hours after treatment with rapamycin (final concentration 5 nM) or with DMSO as a control. Snt2 and Ecm5 were genomically tagged with a 13Myc tag at their C termini. ChIPs were performed using a Myc antibody on either Snt2-Myc or Ecm5-Myc strains, or on untagged wildtype strain (BY4741) as a control. Inputs and ChIPs from untagged strain were sequenced as controls.
Project description:Mitotic entry is accompanyed by the expression of a cluster of so called mitotic genes, whose activation is critical for mitosis in human and yeast cells. We found a link between the transcription machinery and cell cycle control network at mitosis in fission yeast, involving the Cdk8 kinase dependent phosphorylation of the fork head transcription factor Fkh2. We have generated a non-phosphorylatable fkh2 mutant (fkh2-S2A) also. We have used microarrays to study the gene expression changes in fkh2 deletion and phosphomutants vs Wt in exponentially growing fission yeast cells to detect how the phosphorylation may affect global and mitotic gene expression. RNA samples were taken from exponentially growing fission yeast cells and hybridized to affymetrix microarrays: wild type, fkh2delta and fkh2-S2A mutants
Project description:Rpb4/7 binds RNA Polymerase II (Pol II) transcripts co-transcriptionally and accompanies them throughout their lives. By virtue of its capacity to interact with key regulators (e.g., Pol II, eIF3, Pat1) both temporarily and spatially, Rpb4/7 regulates the major stages of the mRNA lifecycle. Here we show that Rpb4/7 can undergo over 100 combinations of post-translational modifications (PTMs). Remarkably, the Rpb4/7 PTMs repertoire changes as the mRNA/Rpb4/7 complex progresses from one stage to the next. A mutagenesis approach in residues that undergo PTMs suggests that temporal Rpb4 PTMs regulate its interactions with key regulators of gene expression that control transcriptional and post-transcriptional stages. Moreover, one mutant type specifically affects mRNA synthesis despite its normal association with Pol II, whereas the other affects both mRNA synthesis and decay; both types disrupt the balance between mRNA synthesis and decay (‘mRNA buffering’) and the cell’s capacity to respond to the environment. Taken together, we propose that temporal Rpb4/7 PTMs are involved in cross talks among the various stages of the mRNA lifecycle.
Project description:The experiments were designed to interrogate the genetic interaction relationship between the TOR signalling pathway and the UPS-proteasome pathway in gene expression and cell growth. Yeast cells (BY4742pdr5delta) were treated with the drug vehicle, MG132 (50uM), rapamycin (200ng/ml) or both drugs. Samples in triplicates were taken at 0, 1, 2 and 3hours after treatment. Transcriptome were assayed using Affimetrixs genechips (Yeast 2).
Project description:To identify RNAs specifically associated with potential RBPs, yeast cells expressing TAP-tagged RBP or the wild-type strain BY4741 (mock control) were grown to mid-log phase in rich medium and harvested by centrifugation. RNA affinity isolations were essentially performed as described (Gerber et al. 2004 PLoS Biol.; see protocol). In brief, TAP-tagged protein were captured from cell extracts with IgG coupled agarose beads (Sigma) and released by incubation with a site-specific protease (AcTEV, Sigma). from the extract (input) and from the affinity isolates was purified with the RNeasy Mini/ Micro Kit (Qiagen). RNAs were reverse transcribed using a mixture of oligo-dT and random nonamer oligos in the presence of amino-allyl dUTP/dNTP mixture. cDNAs were fluorescently labeled and hybridized on yeast oligo microarrays over night at 42 degrees in formamide-based hybridization buffer. Antigenic peptide used in IP: TAP-tag An all pairs experiment design type is where all labeled extracts are compared to every other labeled extract.
Project description:To identify RNAs specifically associated with Gis2p, cells expressing TAP-tagged Gis2 or the wild-type strain BY4741 (mock control) were grown to mid-log phase in rich medium and harvested by centrifugation. RNA affinity isolations were essentially performed as described (Gerber et al. 2004 PLoS Biol.; see associated protocol 526). In brief, TAP-tagged protein were captured from cell extracts with IgG coupled agarose beads (Sigma) and released by incubation with a site-specific protease (AcTEV, Sigma). from the extract (input) and from the affinity isolates was purified with the RNeasy Mini/ Micro Kit (Qiagen). RNAs were reverse transcribed using a mixture of oligo-dT and random nonamer oligos in the presence of amino-allyl dUTP/dNTP mixture. cDNAs were fluorescently labeled and hybridized on yeast oligo microarrays over night at 42 degrees in formamide-based hybridization buffer. Set of arrays that are part of repeated experiments Genotype: TAP-tagged Gis2 expressing or wild-type strain BY4741 (wt/gis2) Biological Replicate