Project description:RNA-Seq analysis was carried out to investigate the effects of selective CDK8/19 inhibitor Senexin B and SNX631 on gene expression in LNCaP prostate cancer cells treated with or without androgen.
Project description:RNA-Seq analysis was carried out to investigate the effects of selective CDK8/19 inhibitor Senexin B on gene expression in HEK293 cells (293-WT) or the CDK8/19 double-knockout (293-dKO) derivatives.
Project description:Cortistatin A (CA) is a highly selective inhibitor of the Mediator kinases CDK8 and CDK19. Using CA, we report here the first large-scale identification of Mediator kinase substrates in human cells (HCT116). Among over 16,000 quantified phosphosites, we identified 78 high-confidence Mediator kinase targets within 64 proteins, including DNA-binding transcription factors and proteins associated with chromatin, DNA repair, and RNA polymerase II. Although RNA-Seq data correlated with Mediator kinase targets, CA effects on gene expression were limited and distinct from CDK8 or CDK19 knockdown. Quantitative proteome analyses, which tracked about 7,000 proteins across six time points (0 â?? 24h), revealed that CA selectively affected pathways implicated in inflammation, growth, and metabolic regulation; contrary to expectations, increased turnover of Mediator kinase targets was not generally observed. Collectively, these data support Mediator kinases as regulators of chromatin and RNA polymerase II activity and suggest cellular roles beyond transcription, including metabolism and DNA repair. HCT116 cells were treated with either 100nM CA or DMSO in biological triplicate for each population (6 samples total). Treatment was for 24h for compound and vehicle.
Project description:RNA-Seq analysis was carried out to investigate the effects of selective CDK8/19 inhibitor Senexin B (different treatment period) and knockout/re-expression of CDK8 and CDK19 proteins) on gene transcription in HEK293 cells
Project description:Cyclin Dependent Kinases CDK8 and CDK19 (Mediator kinase) are regulatory components of the Mediator complex, a highly conserved complex that fine tunes transcriptional output. While Mediator kinase has been implicated in the transcriptional control of key pathways necessary for development and growth, its function in vivo has not been well described. Herein, we report the consequences of complete ablation of both Cdk8/19 on tissue homeostasis. We show that intestinal epithelial specific deletion of Mediator kinase leads to a distinct defect in secretory progenitor differentiation with broad loss of the intestinal secretory cell types. Using a phospho-proteogenomic approach, we show that the Cdk8/19 kinase module interacts with and phosphorylates components of the chromatin remodeling complex Swi/Snf in intestinal epithelial cells. Genomic localisation of Swi/Snf and Mediator shows Cdk8/19-dependent genomic binding at distinct super-enhancer loci within key lineage specification genes, including the master regulator of secretory differentiation ATOH1. Using CRISPRi/CRISPRa, we identify a distinct Mediator-Swi/Snf bound enhancer element that is necessary and sufficient for ATOH1 expression in a Mediator-kinase dependent manner. As such, these studies uncover a newly described transcriptional mechanism of ATOH1-dependent intestinal cell specification that is dependent on the coordinated interaction of the chromatin remodeling complex Swi/Snf and Mediator complex.
Project description:Cyclin Dependent Kinases CDK8 and CDK19 (Mediator kinase) are regulatory components of the Mediator complex, a highly conserved complex that fine tunes transcriptional output. While Mediator kinase has been implicated in the transcriptional control of key pathways necessary for development and growth, its function in vivo has not been well described. Herein, we report the consequences of complete ablation of both Cdk8/19 on tissue homeostasis. We show that intestinal epithelial specific deletion of Mediator kinase leads to a distinct defect in secretory progenitor differentiation with broad loss of the intestinal secretory cell types. Using a phospho-proteogenomic approach, we show that the Cdk8/19 kinase module interacts with and phosphorylates components of the chromatin remodeling complex Swi/Snf in intestinal epithelial cells. Genomic localisation of Swi/Snf and Mediator shows Cdk8/19-dependent genomic binding at distinct super-enhancer loci within key lineage specification genes, including the master regulator of secretory differentiation ATOH1. Using CRISPRi/CRISPRa, we identify a distinct Mediator- Swi/Snf bound enhancer element that is necessary and sufficient for ATOH1 expression in a Mediator-kinase dependent manner. As such, these studies uncover a newly described transcriptional mechanism of ATOH1-dependent intestinal cell specification that is dependent on the coordinated interaction of the chromatin remodeling complex Swi/Snf and Mediator complex.
