Project description:Histone acetylation is important for the activation of gene transcription but little is known about its direct ‘read/write’ mechanisms. Here, we report cryo-electron microscopy structures in which a p300/CBP multidomain monomer recognizes histone H4 N-terminal tail (NT) acetylation (ac) in a nucleosome and acetylates non-H4 histone NTs within the same nucleosome. p300/CBP not only recognized H4NTac via the bromodomain pocket responsible for ‘reading’, but also interacted with the DNA minor grooves via the outside of that pocket. This directed the catalytic center of p300/CBP to one of the non-H4 histone NTs. The primary target that p300 ‘writes’ by ‘reading’ H4NTac was H2BNT, and H2BNTac promoted H2A-H2B dissociation from the nucleosome. We propose a model in which p300/CBP ‘replicates’ histone NT acetylation within the H3-H4 tetramer to inherit epigenetic storage, and ‘transcribes’ it from the H3-H4 tetramer to the H2B-H2A dimers to activate context-dependent gene transcription through local nucleosome destabilization.
Project description:We have performed RNA-seq on mouse islets lacking all p300 (p300 KO), all CBP (CBP-null), and one copy of CBP and all p300 (triallelic). The data revealed that p300 and CBP regulate some distinct but largely overlapping genes in islets. This was further confirmed by GO term and transcription factor target analyses, which suggested that these coactivators regulate genes that function similarly and converge to Hnf1a pathway.
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.
Project description:Prostate cancer is driven by oncogenic transcription factor enhanceosomes comprising chromatin and epigenetic regulators. The lysine acetyltransferases p300 and CBP are key cofactors that activate enhancers through histone acetylation. Here, we identify p300/CBP-mediated multisite acetylation of the histone H2B N-terminus (H2BNTac) as a defining feature of oncogenic enhanceosomes in androgen receptor (AR)-positive prostate cancer. p300/CBP are essential for AR and ERG transcriptional activity, and their dual degradation eliminates H2BNTac and H3K27ac marks at hyperactive enhancers more effectively than targeting either paralog or bromodomains alone. Cytotoxicity profiling across >900 cell lines revealed that tumors with high H2BNTac, including AR-positive prostate cancer, are selectively dependent on p300/CBP. In preclinical models, systemic p300/CBP degradation inhibited tumor growth, synergized with AR antagonists, and showed no evident toxicity. These findings position H2BNTac as a key epigenetic marker of enhancer addiction and support dual p300/CBP degradation as a promising therapy for enhancer-driven cancers.
Project description:Prostate cancer is driven by oncogenic transcription factor enhanceosomes comprising chromatin and epigenetic regulators. The lysine acetyltransferases p300 and CBP are key cofactors that activate enhancers through histone acetylation. Here, we identify p300/CBP-mediated multisite acetylation of the histone H2B N-terminus (H2BNTac) as a defining feature of oncogenic enhanceosomes in androgen receptor (AR)-positive prostate cancer. p300/CBP are essential for AR and ERG transcriptional activity, and their dual degradation eliminates H2BNTac and H3K27ac marks at hyperactive enhancers more effectively than targeting either paralog or bromodomains alone. Cytotoxicity profiling across >900 cell lines revealed that tumors with high H2BNTac, including AR-positive prostate cancer, are selectively dependent on p300/CBP. In preclinical models, systemic p300/CBP degradation inhibited tumor growth, synergized with AR antagonists, and showed no evident toxicity. These findings position H2BNTac as a key epigenetic marker of enhancer addiction and support dual p300/CBP degradation as a promising therapy for enhancer-driven cancers.
Project description:A structure-function study of NF-kB subunit RelA and coactivator CBP/p300 interaction reveals the critical role of CBP/p300 in recruitment of RelA to its target promoter site.
Project description:A structure-function study of NF-kB subunit RelA and coactivator CBP/p300 interaction reveals the critical role of CBP/p300 in recruitment of RelA to its target promoter site. mRNA profiles of unstimulated or stimulated with TNFa rela-/- MEF reconstituted with RelA wild type or mutants were generated by deep sequencing, in duplicate
Project description:Through ChIP-Seq analysis with the Illumina Whole Genome Analyzer, we identify binding sites for P300 (EP300) and CBP (CREBBP) in Human glioblastoma T98G cells that were cell cycle synchronized before and after stimulation. In our analysis, we focused on the identification of genes differentially bound by P300 and CBP. ChIP-seq with P300 and CBP antibodies over 2 timepoints