Effect of truncating the RNAPII CTD on RNAPII genome-wide association
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ABSTRACT: ChIP-chip by array of Rpb3 localization in yeast with different CTD lenghts and with or without CDK8 deletion to determine the role of CTD length and Cdk8 on RNAPII localization
Project description:ChIP-chip by array of S. cerevisiae cells to investigate the genome wide occupancy of phospho-S2 and phospho-S5 forms of the RNAPII-CTD. ChIP-chip by array of S. cerevisiae cells to investigate the genome wide occupancy of Ste12 and Tec1.
Project description:Experiment to obtain the genome-wide distribution of DNA:RNA hybrid prone loci in Saccharomyces cerevisiae by DNA:RNA immunoprecipitation and tiling microarray (DRIP-chip). Samples: wild type, Rnase H deletion mutant, hpr1 deletion mutant, sen1-1 temperature sensitive mutant.
Project description:Sgs1 is a DNA helicase with roles in DNA replication and repair. DNA repair proteins have been linked to genome instability in part by altering the landscape of DNA:RNA hybrids. Here, we mapped the Sgs1 binding profile along with the profile of DNA:RNA hybrids and gammaH2A genome-wide in an effort to identify direct vs indirect effects of Sgs1 in DNA:RNA hybrid and gammaH2A distribution. The wild type DNA:RNA hybrid sample was reported previously in E-MTAB-2388.
Project description:Rad50 is a component of the conserved MRE11-RAD50-NBS1 (MRN) complex, which functions in genome stability and the cell’s ability to deal with stalled DNA replication forks. We identified Rad50 as a factor important for R-loop tolerance and thus mapped DNA:RNA hybrids in Rad50KO cells and compare them to previously reported wild-type and Sgs1KO profiles.
Project description:To define the molecular regulators required for differential pattern of H3K79 methylation by Dot1, we performed a GPS screen and discovered that the components of the cell cycle-regulated SBF complex were required for normal levels of H3K79 di- but not trimethylation. Genome-wide mapping revealed that H3K79 di- and trimethylation to present a mutually exclusive pattern on chromatin with M/G1 cell-cycle-regulated genes significantly enriched for H3K79 dimethylation. Since H3K79 trimethylation requires prior monoubiquitination of H2B, we performed genome-wide profiling of H2BK123 monoubiquitination and showed that H2BK123 monoubiquitination is excluded from cell cycle regulated genes and sites containing H3K79me2 but not from H3K79me3 containing regions. A genome-wide screen for factors responsible for the establishment/removal of H3K79 dimethylation resulted in the identification of several genes including NRM1 and WHI3, which both impact the transcription by the SBF, and MBF complexes, further linking the regulation of H3K79's methylation status to the cell cycle.
Project description:The C-terminal domain (CTD) of RNA polymerase II (RNAPII) is composed of heptapeptide repeats, which play a key regulatory role in gene expression. Using genetic interaction and mRNA expression analysis we found that truncating the CTD resulted in distinct changes to cellular function. Truncating the CTD altered RNAPII occupancy to not only cause decreases, but also increases in mRNA levels. The latter were largely mediated by promoter elements, and in part were linked to the transcription factor Rpn4. The mediator subunit Cdk8 was enriched at promoters of these genes, and its removal not only restored normal mRNA and RNAPII occupancy levels, but also reduced the abnormally high cellular amounts of Rpn4. This suggested a positive role of Cdk8 in relationship to RNAPII, which contrasted with the negative role at the activated INO1 gene. Here, loss of CDK8 suppressed the reduced mRNA expression and RNAPII occupancy levels of CTD truncation mutants.
Project description:The C-terminal domain (CTD) of RNA polymerase II (RNAPII) is composed of heptapeptide repeats, which play a key regulatory role in gene expression. Using genetic interaction and mRNA expression analysis we found that truncating the CTD resulted in distinct changes to cellular function. Truncating the CTD altered RNAPII occupancy to not only cause decreases, but also increases in mRNA levels. The latter were largely mediated by promoter elements, and in part were linked to the transcription factor Rpn4. The mediator subunit Cdk8 was enriched at promoters of these genes, and its removal not only restored normal mRNA and RNAPII occupancy levels, but also reduced the abnormally high cellular amounts of Rpn4. This suggested a positive role of Cdk8 in relationship to RNAPII, which contrasted with the negative role at the activated INO1 gene. Here, loss of CDK8 suppressed the reduced mRNA expression and RNAPII occupancy levels of CTD truncation mutants. Two channel microarrays were used. RNA isolated from a large amount of wt yeast from a single culture was used as a common reference. This common reference was used in one of the channels for each hybridization and used in the statistical analysis to obtain an average expression-profile for each deletion mutant relative to the wt. Two independent cultures were hybridized on two separate microarrays. For the first hybridization the Cy5 (red) labeled cRNA from the deletion mutant is hybridized together with the Cy3 (green) labeled cRNA from the common reference. For the replicate hybridization, the labels are swapped. Each gene is represented twice on the microarray, resulting in four measurements per mutant. Using the Erlenmeyer growth protocol up to five deletion strains were grown on a single day. In the tecan platereader, up to eleven deletion strains could be grown on a single day. Wt cultures were grown parallel to the deletion mutants to assess day-to-day variance.