Saccharomyces cerevisiae
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA320535 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Mediator is a highly conserved transcriptional coactivator organized into four modules, namely Tail, Middle, Head and Kinase (CKM). Previous work suggests regulatory roles for Tail and CKM, but an integrated model for these activities is lacking. Here, we analyzed the genome-wide distribution of Mediator subunits in wild-type and mutant yeast cells in which RNA polymerase II promoter escape is blocked allowing detection of transient Mediator forms. We found that while all modules are recruited to upstream activated regions (UAS), assembly of Mediator within the pre-initiation complex is accompanied by the release of CKM. Surprisingly, our data show that CKM regulates Mediator-UAS interaction rather than Mediator-promoter association. In addition, while Tail is required for Mediator recruitment to UAS, Tail-less Mediator nevertheless interacts with core promoters. Collectively, our data suggest that the essential function of Mediator is mediated by Head and Middle at core promoters, while Tail and CKM play regulatory roles.
2016-10-20 | GSE81127 | GEO
Project description:Mediator is a highly conserved transcriptional coactivator organized into four modules, namely Tail, Middle, Head and Kinase (CKM). Previous work suggests regulatory roles for Tail and CKM, but an integrated model for these activities is lacking. Here, we analyzed the genome-wide distribution of Mediator subunits in wild-type and mutant yeast cells in which RNA polymerase II promoter escape is blocked allowing detection of transient Mediator forms. We found that while all modules are recruited to upstream activated regions (UAS), assembly of Mediator within the pre-initiation complex is accompanied by the release of CKM. Interestingly, our data show that CKM regulates Mediator-UAS interaction rather than Mediator-promoter association. In addition, while Tail is required for Mediator recruitment to UAS, Tail-less Mediator nevertheless interacts with core promoters. Collectively, our data suggest that the essential function of Mediator is mediated by Head and Middle at core promoters, while Tail and CKM play regulatory roles.
2016-10-25 | GSE81107 | GEO
Project description:The Mediator coactivator complex is divided into four modules: head, middle, tail, and kinase. Deletion of the architectural subunit Med16 separates core Mediator (cMed), comprising the head, middle, and scaffold (Med14), from the tail. However, the direct global effects of tail/cMed disconnection are unclear. We find that rapid depletion of Med16 downregulates genes that require the SAGA complex for full expression, consistent with their reported tail dependence, but also moderately overactivates TFIID-dependent genes in a manner partly dependent on the separated tail, which remains associated with upstream activating sequences. Suppression of TBP dynamics via removal of the Mot1 ATPase partially restores normal transcriptional activity to Med16-depleted cells, suggesting that cMed/tail separation results in an imbalance in the levels PIC formation at SAGA-requiring and TFIID-dependent genes. We suggest that the preferential regulation of SAGA-requiring genes by tailed Mediator helps maintain a proper balance of transcription between these genes and those more dependent on TFIID.
2021-07-30 | GSE179765 | GEO
Project description:The Mediator coactivator complex is divided into four modules: head, middle, tail, and kinase. Deletion of the architectural subunit Med16 separates core Mediator (cMed), comprising the head, middle, and scaffold (Med14), from the tail. However, the direct global effects of tail/cMed disconnection are unclear. We find that rapid depletion of Med16 downregulates genes that require the SAGA complex for full expression, consistent with their reported tail dependence, but also moderately overactivates TFIID-dependent genes in a manner partly dependent on the separated tail, which remains associated with upstream activating sequences. Suppression of TBP dynamics via removal of the Mot1 ATPase partially restores normal transcriptional activity to Med16-depleted cells, suggesting that cMed/tail separation results in an imbalance in the levels of PIC formation at SAGA-requiring and TFIID-dependent genes. We suggest that the preferential regulation of SAGA-requiring genes by tailed Mediator helps maintain a proper balance of transcription between these genes and those more dependent on TFIID.
2021-07-30 | GSE171981 | GEO
Project description:The Mediator coactivator complex is divided into four modules: head, middle, tail, and kinase. Deletion of the architectural subunit Med16 separates core Mediator (cMed), comprising the head, middle, and scaffold (Med14), from the tail. However, the direct global effects of tail/cMed disconnection are unclear. We find that rapid depletion of Med16 downregulates genes that require the SAGA complex for full expression, consistent with their reported tail dependence, but also moderately overactivates TFIID-dependent genes in a manner partly dependent on the separated tail, which remains associated with upstream activating sequences. Suppression of TBP dynamics via removal of the Mot1 ATPase partially restores normal transcriptional activity to Med16-depleted cells, suggesting that cMed/tail separation results in an imbalance in the levels PIC formation at SAGA-requiring and TFIID-dependent genes. We suggest that the preferential regulation of SAGA-requiring genes by tailed Mediator helps maintain a proper balance of transcription between these genes and those more dependent on TFIID.
2021-07-30 | GSE169747 | GEO
Project description:The Mediator coactivator complex is divided into four modules: head, middle, tail, and kinase. Deletion of the architectural subunit Med16 separates core Mediator (cMed), comprising the head, middle, and scaffold (Med14), from the tail. However, the direct global effects of tail/cMed disconnection are unclear. We find that rapid depletion of Med16 downregulates genes that require the SAGA complex for full expression, consistent with their reported tail dependence, but also moderately overactivates TFIID-dependent genes in a manner partly dependent on the separated tail, which remains associated with upstream activating sequences. Suppression of TBP dynamics via removal of the Mot1 ATPase partially restores normal transcriptional activity to Med16-depleted cells, suggesting that cMed/tail separation results in an imbalance in the levels PIC formation at SAGA-requiring and TFIID-dependent genes. We suggest that the preferential regulation of SAGA-requiring genes by tailed Mediator helps maintain a proper balance of transcription between these genes and those more dependent on TFIID.
2021-07-30 | GSE169746 | GEO
Project description:SAGA is a modular cofactor complex that is essential for eukaryotic transcription. SAGA’s complement of ~20 proteins exist within four structurally and functionally distinct modules, two of which are catalytic. Within the KAT module, GCN5 acetylates histone tails, leading to increased chromatin accessibility and bromodomain protein recruitment. The DUB module contains the ubiquitin hydrolase USP22. In yeast, the USP22 ortholog deubiquitylates H2B, resulting in Pol II S2 phosphorylation and subsequent transcriptional elongation. We report here that metazoan SAGA, and USP22 specifically, are required at a more proximal stage in activator-driven transcription, i.e. pre-initiation complex (PIC) assembly. A combination of genome-wide and proteomic analyses revealed that H2B deubiquitylation is not linked to USP22-dependent transcription. Instead, USP22 controls Mediator tail subunit ubiquitylation. Mechanistically, USP22 controls loading of Mediator tail and GTFs onto promoters, with Mediator core recruitment being USP22-independent. These findings place human SAGA function at the earliest steps in activator-driven transcription.
2021-04-12 | GSE158108 | GEO
Project description:SAGA is a modular cofactor complex that is essential for eukaryotic transcription. SAGA’s complement of ~20 proteins exist within four structurally and functionally distinct modules, two of which are catalytic. Within the KAT module, GCN5 acetylates histone tails, leading to increased chromatin accessibility and bromodomain protein recruitment. The DUB module contains the ubiquitin hydrolase USP22. In yeast, the USP22 ortholog deubiquitylates H2B, resulting in Pol II S2 phosphorylation and subsequent transcriptional elongation. We report here that metazoan SAGA, and USP22 specifically, are required at a more proximal stage in activator-driven transcription, i.e. pre-initiation complex (PIC) assembly. A combination of genome-wide and proteomic analyses revealed that H2B deubiquitylation is not linked to USP22-dependent transcription. Instead, USP22 controls Mediator tail subunit ubiquitylation. Mechanistically, USP22 controls loading of Mediator tail and GTFs onto promoters, with Mediator core recruitment being USP22-independent. These findings place human SAGA function at the earliest steps in activator-driven transcription.
2019-10-24 | GSE121798 | GEO
Project description:A Dynamic Model for the Function of Mediator Modules In Vivo
| PRJNA320647 | ENA
Project description:Connection of core and and tail Mediator modules restrains transcription from TFIID-dependent promoters
| PRJNA717787 | ENA