Similar Datasets
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
Project description:The dynamic and reversible acetylation of proteins catalyzed by histone acetyltransferases (HATs) and histone deacetylases (HDACs) was discovered more than 2 decades ago and the enzymatic function of these enzymes are established as a major epigenetic regulatory mechanism of gene transcription. Thus, these epigenetic modifiers are involved in multiple diseases and represent attractive targets for therapeutic intervention. While HDAC inhibitors have been developed and approved by the FDA to treat certain cancers, progress on the development of drug-like HAT inhibitors has lagged. The HAT paralogs p300 and CBP (here called p300/CBP) are key transcriptional co-activators that are essential for a multitude of cellular processes and also implicated in human pathological conditions, including cancer. Current p300/CBP HAT domain inhibitors including natural products and bisubstrate analogs such as Lys-CoA either lack potency and selectivity or suffer from poor cellular permeability. C646 is widely utilized as a tool to inhibit p300/CBP HAT activity, but its off-target activity and reactivity may limit its cellular specificity. Here, we describe A-485 as a potent, selective and drug-like p300/CBP catalytic inhibitor. We show the first high resolution (1.95Å) co-crystal structure of a pharmacologically active small molecule (A-485) bound to the catalytic active site of p300 HAT domain and demonstrate that A-485 is an acetyl-CoA competitive inhibitor of p300/CBP. A-485 selectively inhibited proliferation across lineage-specific tumor types, including several hematological malignancies and androgen receptor-positive prostate cancer. A-485 robustly inhibited the androgen receptor transcriptional program in both androgen sensitive and castrate resistant prostate cancer and inhibited tumor growth in a castration resistant xenograft model. These results demonstrate the feasibility of selectively drugging the catalytic activity of histone acetyltransferases, provide the framework for delineating the enzymatic functions of HATs, and pave the way for the development of novel therapeutics targeting HAT activity.
2017-09-27 | GSE94580 | GEO
Project description:p300 and CBP are highly related histone acetyltransferase (HAT) enzymes that regulate gene expression, and their dysregulation has been linked to cancer and other diseases. p300/CBP is composed of a number of domains including a HAT domain which is inhibited by the small molecule A-485 and an acetyl-lysine binding bromodomain which was recently found to be selectively antagonized by the small molecule I-CBP112. Here we show that the combination of I-CBP112 and A-485 can synergize to inhibit prostate cancer cell proliferation. We find that the combination confers a dramatic reduction in p300 chromatin occupancy compared to the individual effects of blocking either domain alone. Accompanying this loss of p300 on chromatin, combination treatment predominantly leads to the reduction of specific mRNAs including androgen-dependent and pro-oncogenic prostate genes such as KLK3 (PSA) and c-Myc. Consistent with p300 chromatin binding directly affecting gene expression, mRNAs that are significantly reduced by combination treatment also exhibit a strong reduction in p300 chromatin occupancy at their gene promoters. The relatively few mRNAs that are up-regulated upon combination treatment show no correlation with p300 occupancy. These studies provide support for the pharmacologic advantage of concurrent targeting of two domains within one key epigenetic modification enzyme.
2019-12-31 | GSE124642 | GEO
Project description:p300 and CBP are highly related histone acetyltransferase (HAT) enzymes that regulate gene expression, and their dysregulation has been linked to cancer and other diseases. p300/CBP is composed of a number of domains including a HAT domain which is inhibited by the small molecule A-485 and an acetyl-lysine binding bromodomain which was recently found to be selectively antagonized by the small molecule I-CBP112. Here we show that the combination of I-CBP112 and A-485 can synergize to inhibit prostate cancer cell proliferation. We find that the combination confers a dramatic reduction in p300 chromatin occupancy compared to the individual effects of blocking either domain alone. Accompanying this loss of p300 on chromatin, combination treatment predominantly leads to the reduction of specific mRNAs including androgen-dependent and pro-oncogenic prostate genes such as KLK3 (PSA) and c-Myc. Consistent with p300 chromatin binding directly affecting gene expression, mRNAs that are significantly reduced by combination treatment also exhibit a strong reduction in p300 chromatin occupancy at their gene promoters. The relatively few mRNAs that are up-regulated upon combination treatment show no correlation with p300 occupancy. These studies provide support for the pharmacologic advantage of concurrent targeting of two domains within one key epigenetic modification enzyme.
2019-12-31 | GSE124643 | GEO
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.
2023-05-08 | PXD040835 | Pride
Project description:A recently identified pediatric subtype of undifferentiated round cell sarcoma that is driven by fusion between the cell cycle regulator and transcriptional repressor, capicula (CIC) and the transcriptional activator, DUX4 has been identified based on its histology, clinical differences, and aggressiveness. Because CIC-DUX4 acquires the p300-interacting activation domain of DUX4, we hypothesized that its transcriptional activation potential, and thus the oncogenicity of CIC-DUX4, would require p300 or its homologues, CBP. Recently, a new class of histone acetyltransferase inhibitors with high selectivity for p300 and CBP has been described, and two compounds, A-485, and iP300w, have been shown to inhibit p300 and CBP both in vitro and in vivo with iP300w having the ability to reverse gene expression changes caused by DUX4. If this hypothesis is correct, iP300w should potently counteract the CIC-DUX4 gene expression program and might be a particularly effective therapy for CDS. In this study, we confirm this hypothesis, demonstrating that CIC-DUX4 requires p300/CBP for its activity. We also demonstrate that CIC-DUX4 induces a global increase in H3 acetylation, like DUX4, which is reversible with iP300w treatment. We find that CIC-DUX4 activity is potently blocked by iP300w, and that this compound has potent activity against CDS cell lines and in an in vivo cancer xenograft assay.
2021-10-21 | GSE165729 | GEO
Project description:The bromodomain and extraterminal (BET) protein Brd4 is a validated drug target in leukemia, yet its regulatory function in this disease is not well understood. Here, we show that Brd4 chromatin occupancy in acute myeloid leukemia closely correlates with the hematopoietic transcription factors (TFs) Pu.1, Fli1, Erg, C/EBPα, C/EBPβ, and Myb at nucleosome-depleted enhancer and promoter regions. We provide evidence that these TFs, in conjunction with the lysine acetyltransferase activity of p300/CBP, facilitate Brd4 recruitment to their occupied sites to promote transcriptional activation. Moreover, chemical inhibition of BET bromodomains is found to suppress the functional output each hematopoietic TF, thereby interfering with essential lineage-specific transcriptional circuits in this disease. These findings reveal a chromatin-based signaling cascade comprised of hematopoietic TFs, p300/CBP, and Brd4, which supports leukemia maintenance and is suppressed by BET bromodomain inhibition. PolyA selected RNA-Seq for drug treated or shRNA-expressing MLL-AF9 transformed acute myeloid leukemia cells (RN2)
2015-05-01 | E-GEOD-66068 | biostudies-arrayexpress
Project description:The bromodomain and extraterminal (BET) protein Brd4 is a validated drug target in leukemia, yet its regulatory function in this disease is not well understood. Here, we show that Brd4 chromatin occupancy in acute myeloid leukemia closely correlates with the hematopoietic transcription factors (TFs) Pu.1, Fli1, Erg, C/EBPα, C/EBPβ, and Myb at nucleosome-depleted enhancer and promoter regions. We provide evidence that these TFs, in conjunction with the lysine acetyltransferase activity of p300/CBP, facilitate Brd4 recruitment to their occupied sites to promote transcriptional activation. Moreover, chemical inhibition of BET bromodomains is found to suppress the functional output each hematopoietic TF, thereby interfering with essential lineage-specific transcriptional circuits in this disease. These findings reveal a chromatin-based signaling cascade comprised of hematopoietic TFs, p300/CBP, and Brd4, which supports leukemia maintenance and is suppressed by BET bromodomain inhibition. ChIP-Seq for regulatory factors of Brd4 in MLL-AF9 transformed acute myeloid leukemia cells (RN2)
2015-05-01 | E-GEOD-66122 | biostudies-arrayexpress
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
2013-09-09 | E-GEOD-46213 | biostudies-arrayexpress