CRAC of yeast RNA polymerase II in Topoisomerase 1 and 2 depleted cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE217963 | GEO | 2023/05/18
REPOSITORIES: GEO
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Project description:DNA topoisomerases are known to promote transcription in prokaryotes by removing excessive DNA supercoils produced during elongation. However, it is unclear how topoisomerases in eukaryotes are recruited and function in the transcription pathway in the context of nucleosomes. To address this problem we present high-resolution genome wide maps of one of the major eukaryotic topoisomerases, Topoisomerase II (Top2) and nucleosomes in the budding yeast, Saccharomyces cerevisiae. Our data indicate that at promoters Top2 binds primarily to DNA that is nucleosome free. However, while nucleosome loss enables Top2 occupancy the opposite is not the case and the loss of Top2 has little effect on nucleosome density. We also find that Top2 is involved in transcription. Not only is Top2 enriched at highly transcribed genes but Top2 is required redundantly with Top1 for optimal recruitment of RNA polymerase II at their promoters. These findings and the examination of candidate activated genes suggest that nucleosome loss induced by nucleosome remodeling factors during gene activation enable Top2 binding which in turn acts redundantly with Top1 to enhance recruitment of RNA polymerase II.
2011-08-01 | GSE22626 | GEO
Project description:Physiological and pathogen-induced oscillations in the plant cells' redox environment trigger response mechanisms that involve redox-sensitive cysteines and consequent changes in proteins' biochemical and functional characteristics. Arabidopsis thimet oligopeptidases (TOPs) TOP1 and TOP2 are components of the immune signaling and oxidative stress response. Here, TOP1 and TOP2 were evaluated comparatively to understand their role as redox sensors. We show that TOPs catalytic activity is augmented in plants undergoing an immune response and in mutant lines with altered expression of the chloroplastic NTRC impaired in the chloroplast thiol-disulfide regulatory system; ntrc was unable to mount a systemic immune response. Oxidation promoted TOP1 self-interaction to dimers and oligomers; Cys-to-Ala mutagenesis of multiple Cys residues inhibited TOP1 oxidative self-interaction. In contrast, TOP1 lacking the signal peptide (ΔSPTOP1) and TOP2 were detected solely as monomers. Treatment with oxidized glutathione increased the catalytic activities of TOPs; Ala substitution of the unique Cys405 of TOP2 abolished its oxidative activation. The immune regulator ROC1 was identified as a candidate TOPs substrate. TOPs cleaved a ROC1 peptide (ROC1p) at similar and unique cleavage sites; ROC1p concentration helped determine TOPs cleavage specificity. We propose that TOP1 and TOP2 form a proteolysis couple with divergent redox-sensing mechanisms and specificity.
2021-04-19 | PXD024059 | Pride
Project description:Inhibitors of DNA topoisomerase I (TOP1), an enzyme relieving torsional stress of DNA by generating transient single-strand breaks, are clinically used to treat ovarian cancer, small cell lung cancer and cervical cancer. As torsional stress is generated by replication and transcription we tested the effects of clinically used TOP1 inhibitors Topotecan and SN-38 on TNF-induced gene expression. RNA-seq experiments showed that inhibition of TOP1 activity interfered with the vast majority of TNF-triggered genes, while interference with TOP2 activity had only a minor impact. TOP1 inhibition affected the expression of early and late induced genes and the relative strength of gene induction played no role in the sensitivity to TOP1 interfering drugs. These data raise the possibility that the inhibition of inflammatory gene expression contributes to the increased risk of infection seen in some patients treated with TOP1 inhibtors.
2019-06-22 | GSE128798 | GEO
Project description:Topoisomerases are necessary for the expression of neurodevelopmental genes, and are mutated in some patients with autism spectrum disorder (ASD). We have studied the effects of inhibitors of Topoisomerase 1 (Top1) and Topoisomerase 2 (Top2) enzymes on mouse cortical neurons. We find that topoisomerases selectively inhibit long genes (>100kb), with little effect on all other gene expression. Using ChIPseq against RNA Polymerase II (Pol2) we show that the Top1 inhibitor topotecan blocks transcriptional elongation of long genes specifically. Many of the genes inhibited by topotecan are candidate ASD genes, leading us to propose that topoisomerase inhibition might contribute to ASD pathology. [Mouse] 5 biological replicates of transcriptome sequencing (RNAseq) from topotecan treated neurons and vehicle treated controls; Pol2 ChIPseq of topotecan and vehicle treated neurons [Human] Transcriptome sequencing (RNAseq) from topotecan treated neurons and vehicle treated control.
2013-08-30 | E-GEOD-43526 | biostudies-arrayexpress
Project description:During meiotic prophase, concurrent transcription, recombination, and chromosome synapsis place substantial topological strain on chromosomal DNA, but the role of topoisomerases in this context remains poorly defined. Here, we analyzed the roles topoisomerases I and II (Top1 and Top2) during meiotic prophase in Saccharomyces cerevisiae. We show that both topoisomerases accumulate primarily in promoter-containing intergenic regions of actively transcribing genes, including many meiotic double-strand break (DSB) hotspots. Despite the comparable binding patterns, top1 and top2 mutations have different effects on meiotic recombination. TOP1 disruption delays DSB induction and shortens the window of DSB accumulation by an unknown mechanism. By contrast, temperature-sensitive top2-1 mutants exhibit a marked delay in meiotic chromosome remodeling and elevated DSB signals on synapsed chromosomes. The problems in chromosome remodeling were linked to altered Top2 binding patterns rather than a loss of Top2 catalytic activity and stemmed from a defect in recruiting the chromosome remodeler Pch2/TRIP13 to synapsed chromosomes. No chromosomal defects were observed in the absence of TOP1. Our results imply independent roles for topoisomerases I and II in modulating meiotic chromosome structure and recombination.
2020-03-06 | GSE131994 | GEO
Project description:The biological functions of nuclear topoisomerase I (Top1) have been difficult to study because knocking out TOP1 is lethal in metazoans. To reveal the functions of human Top1, we have generated stable Top1siRNA cell lines from colon and breast carcinomas (HCT116-siTop1 and MCF-7-siTop1, respectively). In those cells, Top2 compensates for Top1 deficiency. A prominent feature of the siTop1 cells is genomic instability, with chromosomal aberrations and histone gamma-H2AX foci associated with replication. siTop1 cells also show rDNA and nucleolar alterations, and increased nuclear volume. Genome-wide transcription profiling revealed 55 genes with consistent changes in siTop1 cells. Among them, asparagine synthetase (ASNS) was reduced in siTop1 cells, as it also was in cells with transient Top1 downregulation. Conversely, Top1 complementation increased ASNS, indicating a causal link between Top1 and ASNS expression. Correspondingly, pharmacological profiling showed l-asparaginase hypersensitivity in the siTop1 cells. Resistance to camptothecin, aphidicolin, hydroxyurea and staurosporine, and hypersensitivity to etoposide and actinomycin D demonstrated that Top1, in addition to being the target of camptothecins, also regulates DNA replication, rDNA stability and apoptosis. Overall, our studies demonstrate the pleiotropic nature of human Top1 activities. In addition to its classical DNA nicking-closing functions, Top1 plays critical non-classical roles in genomic stability, gene-specific transcription, and response to various anticancer agents. Keywords: genetic modification design
2008-02-01 | GSE7161 | GEO
Project description:The biological functions of nuclear topoisomerase I (Top1) have been difficult to study because knocking out TOP1 is lethal in metazoans. To reveal the functions of human Top1, we have generated stable Top1siRNA cell lines from colon and breast carcinomas (HCT116-siTop1 and MCF-7-siTop1, respectively). In those cells, Top2 compensates for Top1 deficiency. A prominent feature of the siTop1 cells is genomic instability, with chromosomal aberrations and histone gamma-H2AX foci associated with replication. siTop1 cells also show rDNA and nucleolar alterations, and increased nuclear volume. Genome-wide transcription profiling revealed 55 genes with consistent changes in siTop1 cells. Among them, asparagine synthetase (ASNS) was reduced in siTop1 cells, as it also was in cells with transient Top1 downregulation. Conversely, Top1 complementation increased ASNS, indicating a causal link between Top1 and ASNS expression. Correspondingly, pharmacological profiling showed l-asparaginase hypersensitivity in the siTop1 cells. Resistance to camptothecin, aphidicolin, hydroxyurea and staurosporine, and hypersensitivity to etoposide and actinomycin D demonstrated that Top1, in addition to being the target of camptothecins, also regulates DNA replication, rDNA stability and apoptosis. Overall, our studies demonstrate the pleiotropic nature of human Top1 activities. In addition to its classical DNA nicking-closing functions, Top1 plays critical non-classical roles in genomic stability, gene-specific transcription, and response to various anticancer agents. Experiment Overall Design: We are using Affymetrix whole genome array U133 Plus 2, which is a single color microarray platform. For colon experiments, we analyzed 2 different samples as 4 replicates. For breast experiments, we analyzed 2 samples as replicates.
2008-06-15 | E-GEOD-7161 | biostudies-arrayexpress
Project description:Topoisomerases are necessary for the expression of neurodevelopmental genes, and are mutated in some patients with autism spectrum disorder (ASD). We have studied the effects of inhibitors of Topoisomerase 1 (Top1) and Topoisomerase 2 (Top2) enzymes on mouse cortical neurons. We find that topoisomerases selectively inhibit long genes (>100kb), with little effect on all other gene expression. Using ChIPseq against RNA Polymerase II (Pol2) we show that the Top1 inhibitor topotecan blocks transcriptional elongation of long genes specifically. Many of the genes inhibited by topotecan are candidate ASD genes, leading us to propose that topoisomerase inhibition might contribute to ASD pathology.
2013-08-30 | GSE43526 | GEO
Project description:Topoisomerases are necessary for the expression of neurodevelopmental genes, and are mutated in some patients with autism spectrum disorder (ASD). We have studied the effects of inhibitors of Topoisomerase 1 (Top1) and Topoisomerase 2 (Top2) enzymes on mouse cortical neurons. We find that topoisomerases selectively inhibit long genes (>100kb), with little effect on all other gene expression. Using ChIPseq against RNA Polymerase II (Pol2) we show that the Top1 inhibitor topotecan blocks transcriptional elongation of long genes specifically. Many of the genes inhibited by topotecan are candidate ASD genes, leading us to propose that topoisomerase inhibition might contribute to ASD pathology.
2013-08-30 | GSE43899 | GEO
Project description:We analyed the nucleosome positions by using 2 concentrations of micrococcal nuclease of haploid yeast strains that were grown in galactose containing synthetic complete media. Strains contained AID-tags at the endogeous TOP1 and TOP2 genes. One strain contained OsTIR1 and these cells were either untreated or treated for 60 min with 500 uM auxin.
2023-04-28 | GSE196945 | GEO