BRD4 Prevents the Accumulation of R-loops and Protects Against Transcription-Replication Collision Events and DNA Damage
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE151038 | GEO | 2020/06/15
REPOSITORIES: GEO
Similar Datasets
Project description:Proper chromatin function and maintenance of genomic stability depends on spatiotemporal coordination between the transcription and replication machinery. Loss of this coordination can lead to DNA damage from increased transcription-replication collision events. We report that deregulated transcription following BRD4 loss in cancer cells leads to the accumulation of RNA:DNA hybrids (R-loops) and collisions with the replication machinery causing replication stress and DNA damage. Whole genome BRD4 and γH2AX ChIP-Seq with R-loop IP qPCR reveals that BRD4 inhibition leads to accumulation of R-loops and DNA damage at a subset of known BDR4, JMJD6, and CHD4 co-regulated genes. Interference with BRD4 function causes transcriptional downregulation of the DNA damage response protein TopBP1, resulting in failure to activate the ATR-Chk1 pathway despite increased replication stress, leading to apoptotic cell death in S-phase and mitotic catastrophe. These findings demonstrate that inhibition of BRD4 induces transcription-replication conflicts, DNA damage, and cell death in oncogenic cells.
| S-EPMC7428008 | biostudies-literature
Project description:BRD4 Prevents the Accumulation of R-loops and Protects Against Transcription-Replication Collision Events and DNA Damage
| PRJNA634473 | ENA
Project description:We are reporting here genome wide distribution of BRD4 in bone marrow derived macrophages at steady state level and in reponse to LPS stimulation. In both condition, BRD4 distribution was found to be widespread in intragenic as well as intergenic regions with enrichment specifically near TSS. Characteristically BRD4 signal were highly enriched on enhancers of some active genes and hence were classified as BRD4 rich super-enhancers (>12kb long stretches). Super-enhancers are formed, in some instances by redistribution of BRD4 on LPS stimulated genes. BRD4 binding well correlated PolII binding at the chromatin acetylated at H3K27, H3K9 and H4tetraK. Interestingly many LPS induced BRD4 independent genes, despite BRD4 loss in the KO, maintained PolII binding at the chromatin enriched with acetylated lysines at H3K27, H3K9 and H4tetraK. Additionally among some BRD4 independent LPS inducible genes we detected stronger p65 enrichment in the KO. In contrast, P65 binding was not detected in BRD4 dependent genes. These observations provided evidence of plasticity of epigenetic changes in retaining inflammatory reponses in macrophages.
2019-02-21 | GSE113226 | GEO
Project description:Respiratory Syncytial Virus (RSV) causes severe inflammation and airway pathology in children and the elderly by infecting the epithelial cells of the upper and lower respiratory tract. RSV replication is sensed by intracellular pattern recognition receptors upstream of the IRF and NF-$\upkappa$B transcription factors. These proteins coordinate an innate inflammatory response via Bromodomain containing protein 4 (BRD4), a protein that functions as a scaffold for unknown transcriptional regulators. To better understand the pleiotropic regulatory function of BRD4, we examine the BRD4 interactome and identify how RSV infection dynamically alters it. To accomplish these goals, we leverage native immunoprecipitation and Parallel Accumulation – Serial Fragmentation (PASEF) mass spectrometry to examine BRD4 complexes isolated from human alveolar epithelial cells in the absence or presence of RSV infection. In addition, we explore the role of BRD4's acetyl-lysine binding bromodomains in mediating these interactions by using a highly selective competitive bromodomain inhibitor. We identify 101 proteins that are significantly enriched in the BRD4 complex and are responsive to both RSV-infection and BRD4 inhibition. These proteins are highly enriched in transcription factors and transcriptional coactivators. Among them, we identify members of the AP1 transcription factor complex, a complex important in innate signaling and cell stress responses. We independently confirm the BRD4/AP1 interaction in primary human small airway epithelial cells. We conclude that BRD4 recruits multiple transcription factors during RSV infection in a manner dependent on acetyl-lysine binding domain interactions. This data suggests that BRD4 recruits transcription factors to target its RNA processing complex to regulate gene expression in innate immunity and inflammation.
2021-03-17 | PXD023983 | Pride
Project description:BET-regulated transcriptome and BRD4, BRD2, BRD3 and Pol II ChIP-seq datasets in human ESCs before and after BET inhibition. Transcription factors and chromatin remodeling complexes are key determinants of embryonic stem cell (ESC) identity. In this study, we investigate the role of BRD4, a member of the bromodomain and extra-terminal domain (BET) family of epigenetic reader proteins, in control of ESC identity. We performed RNA-seq analyiss in the presense of small molecule inhibitors of BET proteins to show that BRD4 positively regulates the ESC transcriptome. We also integrated RNA-seq analysis with ChIP-sequencing datasets s for BRD4 (and for other BRD2 and BRD3) to demonstrate that BRD4 binds SEs and regulates the expression of SE-associated pluripotency genes. We have also conducted ChIP-seq analysis for Pol II binding to demonstrate that SE-associated genes depend on BRD4-dependent Pol II binding at TSS and gene body for their productive transcriptional elongation. Total RNA was extracted from samples using the RNeasy Qiagen kit according to the manufacturer’s instructions. Deep sequencing of RNA (1ug) from hESCs FGF- or MS436-treated at day 1 and day 5 was performed as described in (Higgin et al., 2010c). Samples were subjected to PolyA selection using magnetic oligo-dT beads. The resulting RNA samples were then used as input for library construction as described by the manufacturer (Illumina, CA, USA). RNA libraries were then sequenced on the GAIIx system using 50bp single reads. Chromatin for ChIP-sequencing was obtained from FGF-maintained hESCs, vehicle or MS417-treated (at 250nM concentration for 6h) (10 to 20x106 cells/IP). ChIP-Seq libraries were generated using standard Illumina kit and protocol as described in (Ntziachristos et al., 2012). We performed cluster amplification and single read 50 sequencing-method using the Illumina HiSeq 2000, following manufacturer’s protocols.
2014-09-26 | E-GEOD-60171 | biostudies-arrayexpress
Project description:To investigate the mechanism that drives dramatic mistargeting of active chromatin in NUT midline carcinoma, we have identified protein interactions unique to the BRD4-NUT fusion oncoprotein compared to wild type BRD4. Using crosslinking, affinity purification, and mass spectrometry, we identified the EP300 acetyltransferase as uniquely associated with BRD4 through the NUT fusion in both NMC and non-NMC cell types. We also discovered ZNF532 among a small number of candidates associated with BRD4-NUT in NMC patient cells but not present in 293T cells.
2017-04-05 | PXD005786 | Pride
Project description:Analysis of BRD4 ChIP-seq data of two types of human transformed fibroblasts (WT and HGPS) to identify specific and common binding sites for BRD4. Transformed cell lines were obtained by retroviral introduction of TERT (T), V12-HRAS (R) and SV40 large and small T antigens (S) of primary skin fibroblasts for HGPS patients (TRS-HGPS) and age-matched control wild-type individuals (TRS-WT) Abstract: Advanced age and DNA damage accumulation are strong risk factors for cancer. The premature-aging disorder Hutchinson Gilford Progeria Syndrome (HGPS) provides a unique opportunity to study the interplay between DNA damage and aging-associated tumor mechanisms, since HGPS patients do not develop tumors despite elevated levels of DNA damage. Here, we have used HGPS patient cells to identify a protective mechanism to oncogenesis. We find that HGPS cells are resistant to neo-plastic transformation. This resistance is mediated by the bromodomain protein BRD4, which exhibits altered genome-wide binding patterns in transformation-resistant cells leading to inhibition of oncogenic de-differentiation. BRD4 also in-hibits, albeit to a lower extent, the tumorigenic potential of transformed cells from healthy individuals and BRD4-mediated tumor protection is clinically relevant, since a BRD4 gene signature predicts positive clinical outcome in breast and lung cancer. Our results demonstrate a protective function for BRD4 and suggest tissue-specific functions for BRD4 in tumorigenesis. Examination of BRD4 binding events in TRS-WT and TRS-HGPS fibroblasts (2 independent cell lines in each group)
2014-10-02 | E-GEOD-61325 | biostudies-arrayexpress
Project description:BET-regulated transcriptome and BRD4, BRD2, BRD3 and Pol II ChIP-seq datasets in human ESCs before and after BET inhibition. Transcription factors and chromatin remodeling complexes are key determinants of embryonic stem cell (ESC) identity. In this study, we investigate the role of BRD4, a member of the bromodomain and extra-terminal domain (BET) family of epigenetic reader proteins, in control of ESC identity. We performed RNA-seq analyiss in the presense of small molecule inhibitors of BET proteins to show that BRD4 positively regulates the ESC transcriptome. We also integrated RNA-seq analysis with ChIP-sequencing datasets s for BRD4 (and for other BRD2 and BRD3) to demonstrate that BRD4 binds SEs and regulates the expression of SE-associated pluripotency genes. We have also conducted ChIP-seq analysis for Pol II binding to demonstrate that SE-associated genes depend on BRD4-dependent Pol II binding at TSS and gene body for their productive transcriptional elongation.
2014-09-26 | GSE60171 | GEO
Project description:The histone acetyl-reader BRD4 is an important regulator of chromatin structure and transcription, yet factors modulating its activity have remained elusive. Here we describe two complementary screens for genetic and physical interactors of BRD4, which converge on the folate pathway enzyme MTHFD1. We show that a fraction of MTHFD1 resides in the nucleus, where it is recruited to distinct genomic loci by direct interaction with BRD4. Inhibition of either BRD4 or MTHFD1 results in similar changes in nuclear metabolite composition and gene expression, and pharmacologic inhibitors of the two pathways synergize to impair cancer cell viability in vitro and in vivo. Our finding that MTHFD1 and other metabolic enzymes are chromatin-associated suggests a direct role for nuclear metabolism in the control of gene expression.
2019-04-04 | PXD012715 | Pride
Project description:BRD4 Inhibition of spindle cell malignant peripheral nerve sheath tumor (sMPNST) tumor cells Cells were treated with Brd4 shRNA (3 days) or 500 nM JQ1 (2 days) before RNA isolation
2013-09-13 | E-GEOD-50865 | biostudies-arrayexpress