GRO analysis of topoisomerase mutants
Ontology highlight
ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE16673 | GEO | 2010/02/16
SECONDARY ACCESSION(S): PRJNA117389
REPOSITORIES: GEO
Similar Datasets
Project description:Genomic Run-on analysis of topoisomerase mutants (top1-delta/top2ts or top2ts) has been conducted at reference temperature for wt strain and at non-permissive temperature for wt and mutant strains. Keywords: Genomic Run On The analysis includes 3 repeats of the wild type strain (JCW25) at 30ºC and 3 more at 37ºC, 3 repeats of the top2ts mutant (JCW26) at 37ºC and 3 repeats of the double top1 (delta) top2ts mutant at 37ºC. A single genomic DNA hybridization on one of the filters can be used for normalization between gene probes if needed.
2010-06-24 | E-GEOD-16673 | biostudies-arrayexpress
Project description:The discovery that enhancers are regulated transcription units, encoding eRNAs, has raised new questions about the mechanisms of their activation. Here, we report an unexpected molecular mechanism that underlies ligand-dependent enhancer activation, based on DNA nicking to relieve torsional stress from eRNA synthesis. Using dihydrotestosterone (DHT)-induced binding of androgen receptor (AR) to prostate cancer cell enhancers as a model, we show rapid recruitment, within minutes, of DNA topoisomerase I (TOP1) to a large cohort of AR-regulated enhancers. Furthermore, we show that the DNA nicking activity of TOP1 is a prerequisite for robust eRNA synthesis and enhancer activation and is kinetically accompanied by the recruitment of ATR and the MRN complex, followed by additional components of DNA damage repair machinery to the AR-regulated enhancers. Together, our studies reveal a linkage between eRNA synthesis and ligand-dependent TOP1-mediated nicking - a strategy exerting quantitative effects on eRNA expression in regulating AR-bound enhancer-dependent transcriptional programs. Genome-wide binding analysis of AR, TOP1, MRE11 in prostate cancer cell line LNCaP with or without 5alpha-dihydrotestosterone (DHT) treatment. Nascent RNA analysis by global nuclear run-on (GRO-seq) in LNCaP cells transfected with siRNA with or without DHT treatment. Distribution of transcriptionally engaged RNA Pol II in LNCaP cells with or without DHT treatment by precision nuclear run-on and sequencing (PRO-seq).
2015-01-22 | E-GEOD-63202 | biostudies-arrayexpress
Project description:DNA topoisomerase 1 (Top1) inhibitors are mainstays of anticancer therapy. These drugs trap Top1 on DNA, stabilizing the Top1-cleavage complex (Top1-cc). The accumulation of Top1-ccs perturbs DNA replication fork progression, leading to DNA breaks and cell death. By analyzing the genomic occupancy and activity of Top1, we show that cells adapt to treatment with multiple doses of Top1 inhibitor by promoting the degradation of Top1-ccs, allowing cells to better tolerate subsequent doses of Top1 inhibitor. The E3-RING Cullin 3 Ligase in complex with the BTBD1 and BTBD2 adaptor proteins promote Top1-cc ubiquitination and subsequent proteasomal degradation. NEDDylation of Cullin 3 activates this pathway and inhibition of protein NEDDylation or depletion of Cullin 3 sensitizes cancer cells to Top1 inhibitors. Collectively, our data identify a novel NEDD8-Cullin 3 pathway involved in the adaptive response to Top1 inhibitors, which can be targeted to improve the efficacy of Top1 drugs in cancer therapy.
2022-11-04 | GSE212469 | GEO
Project description:DNA topoisomerase 1 (Top1) inhibitors are mainstays of anticancer therapy. These drugs trap Top1 on DNA, stabilizing the Top1-cleavage complex (Top1-cc). The accumulation of Top1-ccs perturbs DNA replication fork progression, leading to DNA breaks and cell death. By analyzing the genomic occupancy and activity of Top1, we show that cells adapt to treatment with multiple doses of Top1 inhibitor by promoting the degradation of Top1-ccs, allowing cells to better tolerate subsequent doses of Top1 inhibitor. The E3-RING Cullin 3 Ligase in complex with the BTBD1 and BTBD2 adaptor proteins promote Top1-cc ubiquitination and subsequent proteasomal degradation. NEDDylation of Cullin 3 activates this pathway and inhibition of protein NEDDylation or depletion of Cullin 3 sensitizes cancer cells to Top1 inhibitors. Collectively, our data identify a novel NEDD8-Cullin 3 pathway involved in the adaptive response to Top1 inhibitors, which can be targeted to improve the efficacy of Top1 drugs in cancer therapy.
2022-11-04 | GSE212468 | GEO
Project description:Topoisomerase I (TOP1) is an essential enzyme that relaxes DNA to prevent and dissipate torsional stress during transcription. However, the mechanisms underlying the regulation of TOP1 activity remain elusive. Using eCLIP and UV-RIP-seq we identify TOP1 as a RNA binding protein (RBP). Using a TOP1 RNA binding mutant and TOP1cc-seq to map TOP1 catalytic activity, we reveal that RNA opposes TOP1 activity as RNAPII commences transcription of active genes. These findings support new insights into the coordinated actions of RNA and TOP1 in regulating DNA topological stress intrinsic to RNAPII-dependent transcription.
2024-08-21 | GSE213403 | GEO
Project description:We report a mechanism through which the transcription machinery directly controls topoisomerase 1 (TOP1) activity to adjust DNA topology throughout the transcription cycle. By comparing TOP1 occupancy using ChIP-Seq, versus TOP1 activity using TOP1-Seq, a method reported here to map catalytically engaged TOP1, TOP1 bound at promoters was discovered to become fully active only after pause-release. This transition coupled the phosphorylation of the carboxyl-terminal-domain (CTD) of RNA polymerase II (RNAPII) with stimulation of TOP1 above its basal rate, enhancing its processivity. TOP1 stimulation is strongly dependent on the kinase activity of BRD4, a protein that phosphorylates Ser2-CTD and regulates RNAPII pause-release. Thus the coordinated action of BRD4 and TOP1 overcame the torsional stress opposing transcription as RNAPII commenced elongation, but preserved negative supercoiling that assists promoter melting at start sites. This nexus between transcription and DNA topology promises to elicit new strategies to intercept pathological gene expression.
2016-04-12 | GSE57628 | 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: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: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. [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