Contrasting roles of the RSC and ISW1/CHD1 chromatin remodelers in RNA polymerase II elongation and termination
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ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE73428 | GEO | 2019/01/16
REPOSITORIES: GEO
Similar Datasets
Project description:Most yeast genes have a nucleosome-depleted region (NDR) at the promoter and an array of regularly spaced nucleosomes phased relative to the transcription start site. We have examined the interplay between RSC (a conserved essential SWI/SNF-type complex that determines NDR size) and the ISW1, CHD1 and ISW2 nucleosome spacing enzymes in chromatin organization and transcription, using isogenic strains lacking all combinations of these enzymes. The contributions of these remodelers to chromatin organization are largely combinatorial, distinct and non-redundant, supporting a model in which the +1 nucleosome is positioned by RSC and then used as a reference nucleosome by the spacing enzymes. Defective chromatin organization correlates with altered RNA polymerase II (Pol II) distribution. RSC-depleted cells exhibit low levels of elongating Pol II and high levels of terminating Pol II, consistent with defects in both termination and initiation, suggesting that RSC facilitates both. Cells lacking both ISW1 and CHD1 show the opposite Pol II distribution, suggesting elongation and termination defects. These cells have extremely disrupted chromatin, with high levels of close-packed di-nucleosomes near the 5’-ends of genes. We propose that ISW1 and CHD1 facilitate Pol II elongation by separating close-packed nucleosomes and by eliminating long linkers to prevent cryptic initiation.
2019-01-16 | GSE117514 | GEO
Project description:We addressed the roles of three nucleosome spacing enzymes (ISW1, ISW2 and CHD1) in specifying chromatin organization in S. cerevisiae.
2016-02-17 | GSE69400 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE32042: Isw1 and Chd1 maintain chromatin organization during transcription GSE32043: Histone exchange in wildtype, isw1, chd1, isw1 chd1 and ioc4 yeast strains GSE32044: Histone H3 K36me3 in wildtype, isw1 and chd1 yeast strains GSE32045: Isw1 and Chd1 maintain chromatin organization during transcription [AcH4 data] GSE36405: Isw1 and Chd1 maintain chromatin organization during transcription [K56ac data] GSE37158: Isw1 and Chd1 maintain chromatin organization during transcription [isw1 chd1 mutant expression] Refer to individual Series
2012-07-24 | E-GEOD-32071 | biostudies-arrayexpress
Project description:We addressed the roles of three nucleosome spacing enzymes (ISW1, ISW2 and CHD1) in specifying chromatin organization in S. cerevisiae. Comparison of budding yeast nucleosome positions obtained using micrococcal nuclease digestion followed by paired-end sequencing (MNase-seq). We sequenced nucleosomes from isogenic strains with the isw1Î, isw2Î or chd1Î mutations in all combinations. We measured gene activity by ChIP-seq for the Rpb3 subunit of RNA polymerase II for some of these mutants.
2016-02-17 | E-GEOD-69400 | biostudies-arrayexpress
Project description:Histone exchange in wildtype, isw1, chd1, isw1 chd1 and ioc4 yeast strains.
2012-07-25 | GSE32043 | GEO
Project description:ISWI-family chromatin remodelers organize nucleosome arrays, while SWI/SNF-family remodelers (RSC) disorganize and eject nucleosomes, implying an antagonism that is largely unexplored in vivo. Here, we describe two independent genetic screens for rsc suppressors that yielded mutations in the promoter-focused ISW1a complex, or mutations in the ‘basic patch’ of histone H4 (an epitope that regulates ISWI activity), strongly supporting RSC-ISW1a antagonism in vivo. RSC and ISW1a largely co-localize, and genomic nucleosome studies using rsc isw1 mutant combinations revealed opposing functions: promoters classified with a nucleosome-deficient region (NDR) gain nucleosome occupancy in rsc mutants, but this gain is attenuated in rsc isw1 double mutants. Furthermore, promoters lacking NDRs have the highest occupancy of both remodelers, consistent with regulation by nucleosome occupancy, and decreased transcription in rsc mutants. Taken together, we provide the first genetic and genomic evidence for RSC-ISW1a antagonism, and reveal different mechanisms at two different promoter architectures. Genome-wide nucleosome occupancy maps in wild-type, mutant RSC, and mutant ISW1 strains were generated by hybridization of mononucleosomal DNA to microarrays. Strains carrying Sth1 degron and either pGal-UBR1 (YBC2191) or ubr1 null (YBC2192) represent RSC null and RSC wildtype, respectively. Strains carrying Sth1 degron isw1 null and either pGal-UBR1 (YBC2467) or ubr1 null (YBC2468) represent RSC null isw1 null and RSC wildtype isw1 null, respectively. Mononucleosomes were isolated from three independent biological replicates from each genotype. Please note that each sample consists of three replicates (i.e. three raw data files) and the sample data table contains combined quantile normalized data of the replicates.
2015-04-01 | E-GEOD-65590 | biostudies-arrayexpress
Project description:ISWI-family chromatin remodelers organize nucleosome arrays, while SWI/SNF-family remodelers (RSC) disorganize and eject nucleosomes, implying an antagonism that is largely unexplored in vivo. Here, we describe two independent genetic screens for rsc suppressors that yielded mutations in the promoter-focused ISW1a complex, or mutations in the ‘basic patch’ of histone H4 (an epitope that regulates ISWI activity), strongly supporting RSC-ISW1a antagonism in vivo. RSC and ISW1a largely co-localize, and genomic nucleosome studies using rsc isw1 mutant combinations revealed opposing functions: promoters classified with a nucleosome-deficient region (NDR) gain nucleosome occupancy in rsc mutants, but this gain is attenuated in rsc isw1 double mutants. Furthermore, promoters lacking NDRs have the highest occupancy of both remodelers, consistent with regulation by nucleosome occupancy, and decreased transcription in rsc mutants. Taken together, we provide the first genetic and genomic evidence for RSC-ISW1a antagonism, and reveal different mechanisms at two different promoter architectures. Total RNA expression was determined by the HybMap protocol, hybridization of total RNA to genomic tiling microarray followed by detection with an anti-RNA-DNA-hybrid antibody. Total RNA was isolated from three independent biological replicates of each strain, including wild type (YBC1894), rsc2ts (YBC1111), isw1 null (YBC1416), ioc3 null (YBC2693), isw1 null rsc2ts (YBC3227), and ioc3 null rsc2ts (YBC3228). Please note that each sample consists of three replicates (i.e. three raw data files) and the sample data table contains combined quantile normalized data of the replicates.
2015-04-01 | E-GEOD-65591 | biostudies-arrayexpress
Project description:ISWI-family chromatin remodelers organize nucleosome arrays, while SWI/SNF-family remodelers (RSC) disorganize and eject nucleosomes, implying an antagonism that is largely unexplored in vivo. Here, we describe two independent genetic screens for rsc suppressors that yielded mutations in the promoter-focused ISW1a complex, or mutations in the ‘basic patch’ of histone H4 (an epitope that regulates ISWI activity), strongly supporting RSC-ISW1a antagonism in vivo. RSC and ISW1a largely co-localize, and genomic nucleosome studies using rsc isw1 mutant combinations revealed opposing functions: promoters classified with a nucleosome-deficient region (NDR) gain nucleosome occupancy in rsc mutants, but this gain is attenuated in rsc isw1 double mutants. Furthermore, promoters lacking NDRs have the highest occupancy of both remodelers, consistent with regulation by nucleosome occupancy, and decreased transcription in rsc mutants. Taken together, we provide the first genetic and genomic evidence for RSC-ISW1a antagonism, and reveal different mechanisms at two different promoter architectures.
2015-04-01 | GSE65593 | GEO
Project description:ISWI-family chromatin remodelers organize nucleosome arrays, while SWI/SNF-family remodelers (RSC) disorganize and eject nucleosomes, implying an antagonism that is largely unexplored in vivo. Here, we describe two independent genetic screens for rsc suppressors that yielded mutations in the promoter-focused ISW1a complex, or mutations in the ‘basic patch’ of histone H4 (an epitope that regulates ISWI activity), strongly supporting RSC-ISW1a antagonism in vivo. RSC and ISW1a largely co-localize, and genomic nucleosome studies using rsc isw1 mutant combinations revealed opposing functions: promoters classified with a nucleosome-deficient region (NDR) gain nucleosome occupancy in rsc mutants, but this gain is attenuated in rsc isw1 double mutants. Furthermore, promoters lacking NDRs have the highest occupancy of both remodelers, consistent with regulation by nucleosome occupancy, and decreased transcription in rsc mutants. Taken together, we provide the first genetic and genomic evidence for RSC-ISW1a antagonism, and reveal different mechanisms at two different promoter architectures.
2015-04-01 | GSE65591 | GEO
Project description:ISWI-family chromatin remodelers organize nucleosome arrays, while SWI/SNF-family remodelers (RSC) disorganize and eject nucleosomes, implying an antagonism that is largely unexplored in vivo. Here, we describe two independent genetic screens for rsc suppressors that yielded mutations in the promoter-focused ISW1a complex, or mutations in the ‘basic patch’ of histone H4 (an epitope that regulates ISWI activity), strongly supporting RSC-ISW1a antagonism in vivo. RSC and ISW1a largely co-localize, and genomic nucleosome studies using rsc isw1 mutant combinations revealed opposing functions: promoters classified with a nucleosome-deficient region (NDR) gain nucleosome occupancy in rsc mutants, but this gain is attenuated in rsc isw1 double mutants. Furthermore, promoters lacking NDRs have the highest occupancy of both remodelers, consistent with regulation by nucleosome occupancy, and decreased transcription in rsc mutants. Taken together, we provide the first genetic and genomic evidence for RSC-ISW1a antagonism, and reveal different mechanisms at two different promoter architectures.
2015-04-01 | GSE65590 | GEO