Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Distinct effects of CDK8 module subunits on cellular growth and proliferation in Drosophila

ABSTRACT: The Mediator complex plays a pivotal role in facilitating RNA polymerase II-dependent transcription in eukaryotes. Within this complex, the CDK8 kinase module (CKM), comprising CDK8, Cyclin C (CycC), Med12, and Med13, serves as a dissociable subcomplex that modulates the activity of the small Mediator complex. Genetic studies in Drosophila have revealed distinct phenotypes associated with mutations in CKM subunits, yet the underlying mechanism has remained unknown. Using Drosophila as a model, we generated transgenic strains to individually or simultaneously deplete the four CKM subunits in all possible combinations, uncovering unique phenotypes in the eyes and wings. Depletion of CDK8-CycC enhanced E2F1 target gene expression and promoted cell-cycle progression, whereas Med12-Med13 depletion had no significant impact on these processes. Conversely, depleting Med12-Med13 altered the expression of ribosomal protein genes and fibrillarin, reduced nascent protein synthesis, indicating a severe reduction in ribosome biogenesis and cellular growth compared to the loss of CDK8-CycC. These findings reveal distinct in vivo roles for CKM subunits, with Med12-Med13 disruption having a more pronounced effect on ribosome biogenesis and protein synthesis .

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE275182 | GEO | 2024/11/20

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Effect of over expression of MED13 IDR in human osteosarcoma U2OS cell line

Project description:The eukaryotic transcriptional Mediator comprises a large Core (cMED) and a dissociable CDK8 kinase module (CKM). cMED recruits RNA polymerase II (Pol II) and promotes pre-initiation complex formation in a manner repressed by the CKM through mechanisms presently unknown. Herein we report cryo-electron microscopy structures of the complete human Mediator and its CKM. Combined with biochemical and functional analyses, these structures provide a mechanistic framework to explain the basis for CKM-mediated repression of cMED function. The CKM binds to cMED at multiple sites through both MED12 and a large intrinsically disordered region (IDR) in MED13. The MED13 IDR blocks Pol II/MED26 recruitment onto cMED by direct occlusion of their corresponding binding sites, leading to functional repression of cMED-dependent transcription. Notably, the CKM is anchored to the cMED Hook, positioning CDK8 downstream and proximal to the transcription start site, which sheds new light on its stimulatory function in post-initiation events.

2024-12-01 | GSE250492 | GEO

Cdk8, Cyclin C, Med12 or Med13 depletion effect on gene expression in Drosophila S2 cells

Project description:Expression profiling following depletion of Mediator Cdk8 module subunits Cdk8, Cyclin C (CycC), Med12 and Med13 72 hours after dsRNA treatment of Drosophila melanogaster S2 cells. Results provide insight into the role of individual Cdk8 module subunits in regulation of transcription. 22 samples. 2 Cdk8 dsRNA, 4 CycC dsRNA, 4 Med12 dsRNA, 4 Med13 dsRNA, 8 control samples including 4 Luciferase (Luc) dsRNA and 4 GFP dsRNA

2014-04-29 | E-GEOD-52343 | biostudies-arrayexpress

Cdk8, Cyclin C, Med12 or Med13 depletion effect on gene expression in Drosophila S2 cells

2014-04-29 | GSE52343 | GEO

The Cdk8 kinase module regulates Mediator-RNA polymerase II interaction

Project description:The Cdk8 kinase module (CKM) is a dissociable part of the coactivator complex Mediator that regulates RNA polymerase II (Pol II transcription. The CKM has negative and positive functions in gene transcription that remain poorly understood at the mechanistic level. Here, we prepare recombinant CKM from the yeast Saccharomyces cerevisiae and show that it binds core Mediator (cMed) to sterically inhibit cMed binding to the Pol II preinitiation complex (PIC) in vitro. We further show that the Cdk8 kinase activity of CKM counteracts CKM-cMed interaction,thereby releasing CKM and enabling Mediator to bind the PIC. Finally, we report that the kinase activity of Cdk8 is required for gene activation during heat shock in vivo, but not under steady state growth conditions. These results converge with previous literature on a model for CKM function. In this model, CKM negatively regulates Mediator function at upstream activating sequences by preventing Mediator binding to the PIC at the promoter. During gene activation, Cdk8 kinase activity may release Mediator and allow its binding to the PIC, thereby stimulating transcription initiation and accounting for the positive function of CKM.

2021-06-16 | GSE161140 | GEO

Requirement for the Mediator kinase module for activation of super-enhancer associated genes in colon cancer cells

Project description:RNA sequencing of HCT116 colon cancer cells following single and combined depletions of Mediator kinase module subunits CDK8, CDK19, MED12, MED13 and MED13L and the BET family protein BRD4. The results provide insight into the shared and specific functions of kinase module subunits and BRD4 in regulation of expression of transcriptional programs including genes associated with cancer acquired super-enhancers.

2018-04-02 | E-MTAB-5873 | biostudies-arrayexpress

Dual function of Med12 in PRC1-dependent gene repression and ncRNA-mediated transcriptional activation

Project description:Mediator is regarded a general co-activator of RNA-Polymerase II dependent transcription but not much is known about its function and regulation in mouse pluripotent embryonic stem cells (mESC). One means of controlling Mediator function is provided by binding of the Cdk8 module (Med12, Cdk8, Ccnc and Med13) to Mediator. Here we report that the Cdk8 module subunit Med12 operates together with PRC1 to silence developmental key genes in the pluripotent state. At the molecular level, PRC1 is required to assemble ncRNA containing Med12-Mediator complexes at promoters of repressed genes. In the course of cellular differentiation the H2A-ubiquitin binding protein Zrf1 abrogates PRC1-Med12 binding and facilitates the recruitment of Cdk8 into Mediator. Remodeling of the Mediator-associated protein complex converts Mediator into a transcriptional enhancer that mediates ncRNA-dependent activation of Polycomb target genes

2016-05-24 | GSE73352 | GEO

Identification of Med26 target genes in Human HEK 293T cells

Project description:Med26 is a subunit of the Human Mediator complex. The Mediator complex is an evolutionarily conserved coregulatory complex that interacts with RNA polymerase II to regulate gene expression. In metazoa, Mediator is composed of some 30 distinct subunits. Mediator exists in multiple, functionally distinct forms that share a common core of subunits and can be distinguished by the presence or absence of a kinase module composed of Med12, Med13, Cdk8, and Cyclin C. In higher eukaryotes, a subset of Mediator complexes is associated with an additional subunit, Med26. This Med26-containing Mediator copurifies from cells with little or no kinase module, but near-stoichiometric Pol II. Evidence suggests that Med26-containing Mediator plays a key role in transcriptional activation however, the mechanism(s) by which Med26 contributes to this process are not known. To identify Med26 target genes, we used Affymetrix U133A plus 2.0 expression arrays to analyze mRNA expression in 293T cells from which Med26 had been depleted by transient transfection by each of three different siRNAs. Three different independent Med26 siRNA knockdowns were compared to a non-targeting control in triplicate, for a total of 12 samples.

2011-08-31 | E-GEOD-28715 | biostudies-arrayexpress

Mediator12 and 13 act as conditional anti-silencing factors in Arabidopsis [RNA-seq]

Project description:Mediator is a multi-protein complex which facilitates the initial steps of gene transcription. Mediator 12 (MED12) and MED13 are components of a module that reversibly associates with the core Mediator complex, and both positively and negatively regulates gene expression. Here, in an Arabidopsis mutant screen for factors that can bypass repressive epigenetic marks, we identified MED12 and MED13 as anti-silencing factors. Both are preferentially required for the expression of genes in the absence of H3K4me3, an activating chromatin mark. Thus, MED12 and MED13 respond to specific epigenetic states and can act as conditional positive gene regulators in Arabidopsis.

2020-12-31 | GSE123561 | GEO