Disruption of TFIIH activities generates a transcriptional stress gene expression response and reveals possible new targets against cancer
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE135256 | GEO | 2020/07/08
REPOSITORIES: GEO
Similar Datasets
Project description:Transcription by RNA Polymerase II (Pol II) in metazoan is regulated in several steps, including preinitiation complex (PIC) formation, initiation, Pol II escape, productive elongation, cotranscriptional RNA-processing and termination. Genome-wide studies have demonstrated that the phenomenon of promoter-bound Pol II pausing is widespread, especially for genes involved in developmental and stimulus-responsive pathways. However, a mechanistic understanding of the paused Pol II states at promoters is limited. For example, at a global level, it’s unclear to what extent the engaged paused Pol II is stably tethered to the promoter or undergoes rapid cycles of initiation and termination. Here we used the small molecule Triptolide (TPL), an XPB/TFIIH inhibitor, to block transcriptional initiation followed by measuring Pol II occupancy by ChIP-seq. This inhibition of initiation enables us to investigate different states of paused Pol II. Specifically, our global analysis reveals that most genes with paused Pol II, as defined by pausing index, show significant clearance of Pol II during the period of TPL treatment. Our study further identifies a group of genes with unexpectedly stably-paused Pol II, with unchanged Pol II occupancy even after one hour of inhibition of initiation. This group of genes constitutes a small portion of all paused genes defined by the conventional criterion of pausing index. These findings could pave the way for evaluating the contribution of different elongation/pausing factors on different states of Pol II pausing in developmental and other stimulus-responsive pathways. ChIP-Seq of total/Ser5P Pol II in HCT116 cells treated with DMSO or TPL in serum starvation/activation or normal conditions. Nascent RNA-seq in HCT116 cells treated with DMSO or TPL in starved condition.
2015-01-05 | E-GEOD-63314 | biostudies-arrayexpress
Project description:Disruption of the enzymatic activities of the transcription factor TFIIH by the small molecules Triptolide (TPL) or THZ1 could be used against cancer. Here, we used the MCF10A-ErSrc oncogenesis model to compare the effect of TFIIH inhibitors between transformed cells and their progenitors. We report that tumour cells exhibited highly increased sensitivity to TPL or THZ1 and that the combination of both had a synergic effect. TPL affects the interaction between XPB and p52, causing a reduction in the levels of XPB, p52 and p8, but not other TFIIH subunits. RNA-Seq and RNAPII-ChIP-Seq experiments showed that although the levels of many transcripts were reduced, the levels of a significant number were increased after TPL treatment, with maintained or increased RNAPII promoter occupancy. A significant number of these genes encode for factors that have been related to tumour growth and metastasis, suggesting that transformed cells might rapidly develop resistance to TPL/THZ inhibitors. Some of these genes were also overexpressed in response to THZ1, of which depletion enhances the toxicity of TPL, and are possible new targets against cancer.
| S-EPMC7333893 | biostudies-literature
Project description:Disruption of TFIIH activities generates a transcriptional stress gene expression response and reveals possible new targets against cancer
| PRJNA558076 | ENA
Project description:CDK7 associates with the 10-subunit TFIIH complex and regulates transcription by phosphorylating the C-terminal domain (CTD) of RNA polymerase II (RNAPII). Few additional CDK7 substrates are known. Here, using the covalent inhibitor SY-351 and quantitative phosphoproteomics, we identified CDK7 kinase substrates in human cells. Among hundreds of high-confidence targets, the vast majority are unique to CDK7 (i.e. distinct from other transcription-associated kinases), with a subset that suggest novel cellular functions. Transcription-associated factors were predominant CDK7 substrates, including SF3B1, U2AF2, and other splicing components. Accordingly, widespread and diverse splicing defects, such as alternative exon inclusion and intron retention, were characterized in CDK7-inhibited cells. Combined with biochemical assays, we establish that CDK7 directly activates other transcription-associated kinases CDK9, CDK12, and CDK13, invoking a “master regulator” role in transcription. We further demonstrate that TFIIH restricts CDK7 kinase function to the RNAPII CTD, whereas other substrates (e.g. SPT5, SF3B1) are phosphorylated by the 3-subunit CDK-activating kinase (CAK; CCNH, MAT1, CDK7). These results suggest new models for CDK7 function in transcription and implicate CAK dissociation from TFIIH as essential for kinase activation. This straightforward regulatory strategy ensures CDK7 activation is spatially and temporally linked to transcription, and may apply toward other transcription-associated kinases.
2020-10-31 | GSE151699 | GEO
Project description:We combined cryo-EM, transcriptomics, and a clinically relevant inhibitor to define how the TFIIH-associated CDK7 kinase coordinately controls the cell cycle and RNA polymerase II (RNAPII) transcription. CDK7 inhibition rapidly blocked expression of constitutively active genes, whereas inducible genes were unaffected. Distinct sets of sequence-specific, DNA-binding transcription factors (TFs) regulate constitutive vs. inducible genes; accordingly, inducible TFs (e.g. HSF1) were refractory to CDK7 inhibition. By contrast, CDK7 was required to maintain activity of a core set of promoter-associated TFs that drive proliferative gene expression programs; these core TFs (n=78) are constitutively active in proliferating cells. Thus, a major biological function for CDK7 is regulation of TFs that drive cell proliferation, revealing an apparent universal mechanism by which CDK7 coordinates RNAPII transcription with cell cycle regulation.
2024-12-19 | GSE262536 | GEO
Project description:We combined cryo-EM, transcriptomics, and a clinically relevant inhibitor to define how the TFIIH-associated CDK7 kinase coordinately controls the cell cycle and RNA polymerase II (RNAPII) transcription. CDK7 inhibition rapidly blocked expression of constitutively active genes, whereas inducible genes were unaffected. Distinct sets of sequence-specific, DNA-binding transcription factors (TFs) regulate constitutive vs. inducible genes; accordingly, inducible TFs (e.g. HSF1) were refractory to CDK7 inhibition. By contrast, CDK7 was required to maintain activity of a core set of promoter-associated TFs that drive proliferative gene expression programs; these core TFs (n=78) are constitutively active in proliferating cells. Thus, a major biological function for CDK7 is regulation of TFs that drive cell proliferation, revealing an apparent universal mechanism by which CDK7 coordinates RNAPII transcription with cell cycle regulation.
2024-12-19 | GSE261575 | GEO
Project description:Transcription by RNA Polymerase II (Pol II) in metazoan is regulated in several steps, including preinitiation complex (PIC) formation, initiation, Pol II escape, productive elongation, cotranscriptional RNA-processing and termination. Genome-wide studies have demonstrated that the phenomenon of promoter-bound Pol II pausing is widespread, especially for genes involved in developmental and stimulus-responsive pathways. However, a mechanistic understanding of the paused Pol II states at promoters is limited. For example, at a global level, it’s unclear to what extent the engaged paused Pol II is stably tethered to the promoter or undergoes rapid cycles of initiation and termination. Here we used the small molecule Triptolide (TPL), an XPB/TFIIH inhibitor, to block transcriptional initiation followed by measuring Pol II occupancy by ChIP-seq. This inhibition of initiation enables us to investigate different states of paused Pol II. Specifically, our global analysis reveals that most genes with paused Pol II, as defined by pausing index, show significant clearance of Pol II during the period of TPL treatment. Our study further identifies a group of genes with unexpectedly stably-paused Pol II, with unchanged Pol II occupancy even after one hour of inhibition of initiation. This group of genes constitutes a small portion of all paused genes defined by the conventional criterion of pausing index. These findings could pave the way for evaluating the contribution of different elongation/pausing factors on different states of Pol II pausing in developmental and other stimulus-responsive pathways.
2015-01-05 | GSE63314 | GEO
Project description:TFIIH is an evolutionarily conserved complex that plays central roles in both RNA polymerase II (pol II) transcription and DNA repair. As an integral component of the pol II Pre-Initiation Complex, TFIIH regulates the activity of the pol II enzyme in numerous ways. One of the essential functions of TFIIH resides in its XPB/Ssl2 subunit. XPB/Ssl2 is an ATP-dependent DNA translocase that stimulates promoter opening prior to transcription initiation. Crosslinking-mass spectrometry and cryo-EM results have shown a conserved interaction network involving XPB/Ssl2 and the C-terminal Hub region of the p52/Tfb2 core subunit. Here, we systematically mutagenized the HubA region of Tfb2 and screened for growth phenotypes in a TFB6 deletion background in Saccharomyces cerevisiae. We identified six lethal and twelve conditional mutants. Growth phenotypes of all but three of the conditional mutants were suppressed in the presence of Tfb6, thus identifying a functional interaction between Tfb2 HubA mutants and Tfb6, a protein that dissociates Ssl2 from TFIIH. Biochemical analysis of p52/Tfb2 mutants with severe growth phenotypes revealed defects in XPB/Ssl2 association. Further characterization of these Tfb2 mutant cells revealed defects in induction of Gal genes, and reduced occupancy TFIIH and pol II at Gal gene promoters, suggesting that functional TFIIH is required for proper Pol II recruitment to PICs in vivo. Consistent with recent structural models of TFIIH, our results identify key residues in the p52/Tfb2 HubA domain that are required for stable incorporation of XPB/Ssl2 into TFIIH, and for pol II transcription.
2022-06-30 | GSE196069 | GEO
Project description:Nucleotide excision repair (NER) is the major DNA repair pathway that removes UV-induced and bulky DNA lesions. There is currently no structure of NER intermediates, which form around the large multisubunit transcription factor IIH (TFIIH). Here we report the cryo-EM structure of an NER intermediate containing TFIIH and the NER factor XPA. Compared to its transcription conformation, the TFIIH structure is rearranged such that its ATPase subunits XPB and XPD bind double- and single-stranded DNA, consistent with their translocase and helicase activities, respectively. XPA releases the inhibitory kinase module of TFIIH, displaces a ‘plug’ element from the DNA-binding pore in XPD, and together with the NER factor XPG stimulates XPD activity. Our results explain how TFIIH is switched from a transcription to a repair factor, and provide the basis for a mechanistic analysis of the NER pathway.
2019-07-02 | PXD013947 | Pride
Project description:Purpose of profiling experiment was to examine effects of a mutation of a subunit of TFIIH, ssl1p, which has ubiquitin ligase activity. The whole complex has previously been shown to have both kinase and helicase activities. We wanted to see if 1) there were general transcriptional defects with these mutations, as there are with other mutations to kinase activity, and 2) if there were transcriptional effects on DNA repair machinery when the mutants were treated with MMS, which is an alkylating agent. Keywords: other
2005-04-20 | GSE2343 | GEO