Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Acetylation of the activated glucocorticoid receptor facilitates its proteasomal degradation thereby limiting hormonal signaling

ABSTRACT: The glucocorticoid (GC) receptor (GR) is a ligand-induced transcription factor regulating metabolism and inflammation. While homologous downregulation of ligand-bound GR limits the response, it also reduces hormone responsiveness resulting in glucocorticoid resistance. Regulatory mechanisms that refine this equilibrium are less understood. Here, we have identified seven lysine acetylation sites in the amino terminal domain of GR, lysine 154 within the regulatory AF-1 region being the dominant acetyl-acceptor. GR-Lys154 acetylation is mediated by p300/CBP in an exclusively agonist-induced manner and correlates with nuclear translocation and transcriptional activity. GR-Lys154 acetylation is removed by the NAD+ dependent deacetylase, SIRT1, indicating dynamic regulation of this mark. Notably, agonist-binding to both the wild type and acetylation-deficient mutant GR elicits similar short-term target gene expression. In contrast, upon extended treatment, the acetylation-deficient mutant shows impaired ubiquitination and higher protein stability with a concomitant increase in chromatin association and transactivation. Taken together, p300/CBP and SIRT1 fine-tune glucocorticoid response by siphoning acetylated GR for proteasomal degradation while GR deacetylation sustains the transcriptional cascade for prolonged periods.

ORGANISM(S): Homo sapiens

PROVIDER: GSE236739 | GEO | 2024/01/16

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Analysis of human acetylation stoichiometry defines mechanistic constraints on protein regulation

Project description:Lysine acetylation is a reversible posttranslational modification that occurs at thousands of sites on human proteins. However, the stoichiometry of acetylation remains poorly characterized, and is important for understanding acetylation-dependent mechanisms of protein regulation. Here we provide accurate, validated measurements of acetylation stoichiometry at 6,829 sites on 2,535 proteins in human cervical cancer (HeLa) cells. Most acetylation occurs at very low stoichiometry (median 0.02%), whereas high stoichiometry acetylation occurs on nuclear proteins involved in gene transcription and on acetyltransferases. Analysis of acetylation copy number shows that histones harbor the majority of acetylated lysine residues in human cells. Class I deacetylases target a greater proportion of high stoichiometry acetylation compared to SIRT1 and HDAC6. The acetyltransferases CBP and p300 catalyze a majority (65%) of high stoichiometry acetylation, yet also target sites with low stoichiometry. This resource dataset provides valuable information for understanding the impact of individual acetylation sites on protein function.

2019-03-12 | PXD009994 | Pride

Time-resolved analysis reveals rapid dynamics and broad scope of the CBP/p300 acetylome

Project description:The acetyltransferases CBP and p300 are multifunctional transcriptional co-activators; however, their acetylation targets, site-specific acetylation kinetics, and function in proteome regulation are incompletely understood. We combined quantitative proteomics with novel CBP/p300-specific catalytic inhibitors, bromodomain inhibitor, and gene knockout to show that CBP/p300 acetylates thousands of sites, including signature histone sites, as well as a multitude of sites on signaling effectors and enhancer-associated transcriptional regulators. Kinetic analysis identified a subset of CBP/p300-regulated sites with very rapid (<30min) acetylation turnover, revealing a dynamic balance between acetylation and deacetylation. Quantification of acetylation, mRNA, and protein abundance after CBP/p300 inhibition reveals a kinetically competent network of gene expression that strictly depends on CBP/p300-catalyzed rapid acetylation. Collectively, our in-depth acetylome analyses reveal systems attributes of CBP/p300 targets, and the resource dataset provides a framework for investigating CBP/p300 functions, as well as for understanding the impact of small molecule inhibitors targeting its catalytic and bromodomain activities.

2018-06-10 | PXD005252 | Pride

PCAF/GCN5-regulated genes in MEFs

Project description:Histone acetyltransferases (HATs) GCN5/PCAF and CBP/p300 are transcription coactivators. However, how these HATs regulate ligand-induced nuclear receptor target gene expression remains unclear. Here we show in mouse embryonic fibroblasts (MEFs), deletion of GCN5/PCAF specifically eliminates acetylation on H3K9 (H3K9Ac) while deletion of CBP/p300 selectively reduces acetylation on H3K18 and H3K27 (H3K18/27Ac). Treating MEFs with a specific ligand for nuclear receptor PPARdelta induces sequential increases of H3K18/27Ac and H3K9Ac on the promoter of PPARdelta target gene Angptl4, which correlates with a robust ligand-induced Angptl4 expression. Inhibiting transcription elongation blocks ligand-induced H3K9Ac but not H3K18/27Ac on Angptl4 promoter. Finally, we show CBP/p300 and their HAT activities are required, while GCN5/PCAF and H3K9Ac are dispensable, for ligand-induced PPARdelta target gene expression in MEFs. These results highlight the substrate and site specificities of HATs in cells, and suggest that GCN5/PCAF- and CBP/p300-mediated histone acetylations play distinct roles in regulating ligand-induced nuclear receptor target gene expression. PCAF and GCN5 have some redundant function. To identify PCAF/GCN5-regulated genes, immortalized MEFs with PCAF knockout and GCN5 conditional knockout were infected with retroviruses expressing either Cre recombinase or vector alone. We prepared duplicated RNAs from either vector or Cre infected cells (PCAF-/-;GCN5+/- or PCAF-/-;GCN5+/-) and RNAs from either Vector or Cre infected the other independently immortalized cells for 6 affymetrix microarray.

2013-12-31 | E-GEOD-20008 | biostudies-arrayexpress

PCAF/GCN5-regulated genes in MEFs

2013-12-31 | GSE20008 | GEO

Targeting P300/CBP reveals discrete regulation of transcription and chromatin accessibility by histone acetylation [RNAseq]

Project description:To test the long-standing paradigm directly linking histone acetylation with chromatin decompaction and transcriptional output, we used integrated epigenomic and transcriptomic analyses following acute inhibition of major cellular lysine acetyltransferases P300 and CBP. We discovered that P300/CBP inhibition dynamically perturbs acetylation kinetics and dramatically suppresses core-transcriptional networks in the absence of changes to chromatin accessibility. CRISPR/Cas9 screening identified NCOR1 and HDAC3 transcriptional co-repressors as the principle antagonists of P300/CBP by counteracting acetylation turnover kinetics. Finally, deacetylation of H3K27 provides nucleation sites for reciprocal methylation switching, a feature that can be exploited therapeutically by concomitant KDM6A and P300 inhibition. Overall, this study indicates that the steady-state histone acetylation-methylation equilibrium functions as a molecular rheostat governing cellular transcription that is amenable to therapeutic exploitation as an anti-cancer regimen.

2021-05-11 | GSE174266 | GEO