MPA and NQO studies (Sevilla)
Ontology highlight
ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE11561 | GEO | 2008/12/30
SECONDARY ACCESSION(S): PRJNA106297
REPOSITORIES: GEO
Similar Datasets
Project description:RNA polymerases deal with obstacles during transcription elongation that need to be removed. One important type of hindrance consists of DNA lesions, which are removed by transcription-coupled repair (TCR). To improve our knowledge of transcription elongation and its coupling to TCR, we performed DNA microarray experiments and used the yeast library of nonessential knock-out mutations to screen for genes conferring resistance to the transcription-elongation inhibitor micophenolic acid and the DNA-damaging agent 4- nitroquinoline-N-oxide. A single sample for each treatment was analyzed.
2008-12-29 | E-GEOD-11561 | biostudies-arrayexpress
Project description:Mouse lymphoma L5178Y cells are treated with 4-NitroQuinoline N-Oxide (4-NQO) [CAS:56-57-5;CHEBI:16907] and harvested at 4 and 24 hours for analysis.
2006-02-13 | E-TOXM-1 | biostudies-arrayexpress
Project description:Transcription-coupled DNA repair (TCR) efficiently removes bulky DNA lesions from transcribed parts of the genome and constitutes a major defence against DNA damage by UV irradiation. TCR begins when RNA polymerase II (Pol II) stalls at a DNA lesion and recruits the Cockayne syndrome protein CsB, the E3 ubiquitin ligase complex CRL4CsA, and the UV-stimulated scaffold protein A (UVSSA). Here we provide five high-resolution structures of Pol II transcription complexes with bound TCR factors and complementary biochemical data. Together with published work, our results converge on a model for the molecular mechanism of transcription-DNA repair coupling. In this model, Pol II stalling triggers the formation of an alternative transcription elongation complex that we call ECact. In ECact, CsB has replaced the elongation factor DSIF, binds the PAF1 complex, and repositions upstream DNA such that it contacts the elongation factor SPT6. The CsB translocase now pulls on the upstream DNA template, thereby pushing Pol II forward. If the lesion cannot be bypassed, Pol II gets stably stalled. CRL4CsA spans over the Pol II clamp to reach the Pol II jaw and direct ubiquitination of RPB1 residue lysine-1268. This triggers the recruitment of TFIIH to UVSSA, which is located at downstream DNA, and enables nucleotide excision repair. Finally, large-scale conformational changes in CRL4CsA enable ubiquitination of CsB and the release of TCR factors, thereby allowing Pol II to resume elongation and continue transcription over repaired DNA.
2022-02-17 | PXD025328 | Pride
Project description:The coordinated transcription of genes involves RNA polymerase II enzymes (RNAPII), which pull DNA through their active sites. DNA lesions in transcribed strands block RNAPII elongation and induce a strong transcriptional arrest. The transcription-coupled repair (TCR) pathway ensures the efficient removal of transcription-blocking DNA lesions, but this is not sufficient to overcome this arrest and resume transcription. Through proteomics screens, we find that the TCR-specific CSB protein loads the evolutionary conserved PAF1 complex (PAF1C) onto RNAPII in promoter-proximal regions specifically in response to DNA damage. PAF1C is dispensable for TCR-mediated repair,but is essential to resume RNA synthesis after UV irradiation, suggesting an unexpected uncoupling between DNA repair and transcription restart. Moreover, we find that PAF1C promotes RNAPII pause release in promoter-proximal regions and subsequently acts as a processivity factor that stimulates transcription elongation waves throughout genes. Our findings expose the molecular basis for a non-canonical PAF1C-dependent pathway that restores transcription throughout the human genome after genotoxic stress.
2021-02-28 | PXD016198 | Pride
Project description:The coordinated transcription of genes involves the regulated release of RNA polymerase II (RNAPII) from promoter-proximal sites into active elongation. DNA lesions in transcribed strands block elongation and induce a strong transcriptional arrest. The transcription-coupled repair (TCR) pathway efficiently removes transcription-blocking DNA lesions, but this is not sufficient to resume transcription. Through proteomics screens, we find that the TCR-specific CSB protein loads the evolutionary conserved PAF1 complex (PAF1C) onto RNAPII in promoter-proximal regions in response to DNA damage. PAF1C is dispensable for TCR-mediated repair, but is essential for recovery of RNA synthesis after UV irradiation, suggesting an uncoupling between DNA repair and transcription recovery. Moreover, we find that PAF1C promotes RNAPII pause release in promoter-proximal regions and subsequently acts as a processivity factor that stimulates transcription elongation throughout genes. Our findings expose the molecular basis for a non-canonical PAF1C-dependent pathway that restores transcription throughout the human genome after genotoxic stress.
2021-01-15 | GSE140930 | GEO
Project description:Correct transcription is crucial for life. However, DNA damage severely impedes elongating RNA Polymerase II (Pol II), causing transcription inhibition and transcription-replication conflicts. Cells have evolved intricate mechanisms to counteract the severe consequence of these transcription-blocking lesions, however the exact mechanism and factors involved remain largely unknown. Here, using a genome-wide CRISPR/cas9 screen, we identified elongation factor ELOF1 as an important new factor in the damage-induced transcription stress response. ELOF1 has an evolutionary-conserved role in TC-NER where it promotes the recruitment of the TC-NER factors UVSSA and TFIIH and facilitates Pol II ubiquitylation to efficiently repair TBLs. Importantly, ELOF1 has an additional role in protecting cells from transcription-mediated replication hindrance, thereby preserving genome stability. Thus, ELOF1 protects the transcription machinery from DNA damage by two distinct mechanisms.
2020-04-18 | GSE148844 | GEO
Project description:Endogenous aldehydes induce inter-strand crosslinks (ICL) and DNA-protein crosslinks (DPC). While DNA-repair and aldehyde-clearance systems cope with cellular toxicity, deficiencies in these mechanisms cause genome-instability disorders. The FA-pathway, defective in Fanconi anemia (FA), specifically removes ICL. In contrast, SPRTN, compromised in Ruijs-Aalfs syndrome, eliminates DPC during replication. However, AMeDS patients lacking aldehyde-detoxification display combined features of FA and Cockayne syndrome, associated with transcription-coupled repair (TCR) deficiency, suggesting a novel repair mechanism for aldehyde-induced DNA lesions in active genes. In this report, we demonstrate efficient resolution of aldehyde-induced transcription-blocking lesions by TCR. Mass-spectrometry and DPC-seq identify the TCR complex and additional factors involved in DPC removal and formaldehyde-induced damage tolerance. Notably, TFIIS-dependent cleavage of stalled-RNAPII transcripts exclusively protects against formaldehyde-induced damage. A mouse-model lacking both aldehyde-clearance and TCR pathways confirms endogenous DPC accumulation in transcribed regions. These findings highlight the importance of DPC removal in preventing transcription-roadblocks and contribute to understanding disorders related to aldehyde clearance and TCR deficiencies.
2024-02-12 | PXD044310 | Pride
Project description:The response to DNA damage-stalled RNA polymerase II (RNAPIIo) involves the assembly of the transcription-coupled repair (TCR) complex on actively transcribed strands. The function of the TCR proteins CSB, CSA and UVSSA and the manner in which the core DNA repair complex, including transcription factor IIH (TFIIH), is recruited are largely unknown. Here, we define the assembly mechanism of the TCR complex in human isogenic knockout cells. We show that TCR is initiated by RNAPIIobound CSB, which recruits CSA through a newly identified CSA-interaction motif (CIM). Once recruited, CSA facilitates the association of UVSSA with stalled RNAPIIo. Importantly, we find that UVSSA is the key factor that recruits the TFIIH complex in a manner that is stimulated by CSB and CSA. Together these findings reveal a sequential and highly cooperative assembly mechanism of TCR proteins and reveal the mechanism for TFIIH recruitment to DNA damage-stalled RNAPIIo to initiate repair.
2020-04-14 | PXD017329 | Pride
Project description:Tobacco use and alcohol consumption are two major contributing factors for head and neck squamous cell carcinoma (HNSCC) carcinogenesis. We combined the 4-nitroquinoline-1-oxide (4-NQO) oral carcinogenesis mouse model and the Meadows-Cook alcohol mouse models and performed next generation genome-wide RNA-sequencing of tongues. We determined changes in transcript levels in four groups: 4-NQO followed by ethanol treatment (4-NQO/EtOH), 4-NQO followed by normal drinking water (4-NQO/Untr.), vehicle control followed by ethanol treatment (V.C./EtOH), and vehicle control followed by normal drinking water (V.C./Untr.). We found that the 494 gene transcripts were significantly changed (at least a 2-fold change where p<0.05) in the V.C./EtOH group compared to the V.C./Untr. group. The 4-NQO/Untr. group had 1,808 transcripts significantly changed compared to the V.C./Untr group, while the 4-NQO/EtOH group had 3,606 significantly changed transcripts as compared to the V.C/Untr. group. This study is the first to show that 4-NQO followed by ethanol cause the largest number of changes in transcript levels in the tongue.
2015-10-06 | GSE62125 | GEO
Project description:Cells employ transcription-coupled repair (TCR) to eliminate transcription-blocking DNA lesions. DNA damage-induced binding of the TCR-specific repair factor CSB to RNA polymerase II (RNAPII) triggers RNAPII ubiquitylation at a single lysine (K1268) by the CRL4CSA ubiquitin ligase. How CRL4CSA is specifically directed toward the K1268 site is unknown. Here, we identify ELOF1 as the missing link that facilitates RNAPII ubiquitylation, a key signal for the assembly of downstream repair factors. This function requires its constitutive interaction with RNAPII close to the K1268 site, revealing ELOF1 as a specificity factor that interacts with and positions CRL4CSA for optimal RNAPII ubiquitylation. Drug-genetic interaction screening also reveals a CSB-independent compensatory pathway in which ELOF1 protects cells against DNA replication stress by preventing DNA damage-induced R-loops. Our study offers key insights into the molecular mechanisms of TCR and provides a genetic framework of the interplay between the transcriptional stress response and DNA replication.
2021-04-21 | PXD024051 | Pride