Project description:we performed CUT&RUN to comprehensively map genomic loci bound to BRD2 in Calu-3 cells. We also included H3K4me3 and IgG antibodies as postive and negative controls, repectively
Project description:we performed CUT&RUN to comprehensively map genomic loci bound to BRD2 in control and BRD2 knockdown Calu-3 cells. We also included H2A.Z, H3K4me3 and IgG antibodies.
Project description:We performed RNA sequencing of Calu-3 cells after treatment with the BET-domain inhibitors JQ-1 and ABBV-744 as well as BRD2 CRISPRi knockdown. We also included CRISPRi knockdown of two other validated hit genes from our screen, COMP and ACE2.
Project description:Background: Histone post-translational modifications (PTMs) constitute a branch of epigenetic mechanisms that can control the expression of eukaryotic genes in a heritable manner. Recent studies have identified several PTM-binding proteins containing diverse specialized domains whose recognition of specific PTM sites leads to gene activation or repression. Here, we present a high-throughput proteogenomic platform designed to characterize the nucleosomal make-up of chromatin enriched with a set of histone PTM-binding proteins known as histone PTM readers. We support our findings with gene expression data correlating to PTM distribution. Results: We isolated human mononucleosomes bound by the bromodomain-containing proteins Brd2, Brd3 and Brd4, and by the chromodomain-containing heterochromatin proteins HP1alpha and HP1beta. Histone PTMs were quantified by mass spectrometry (ChIP-qMS), and their associated DNAs were mapped using deep sequencing. Our results reveal that Brd- and HP1-bound nucleosomes are enriched in histone PTMs consistent with actively transcribed euchromatin and silent heterochromatin, respectively. Data collected using RNA-Seq (GSM301568) show that Brd-bound sites correlate with highly expressed genes. In particular, Brd3 and Brd4 are most enriched on nucleosomes located within HOX gene clusters, whose expression is reduced upon Brd4 depletion by shRNA. Conclusions: Proteogenomic mapping of histone PTM readers, alongside the characterization of their local chromatin environments and transcriptional information, should prove useful for determining how histone PTMs are bound by these readers and how they contribute to distinct transcriptional states. Comparison of Brd2 and HP1b shRNA knockdown HEK293 cells to control knockdown HEK293 cells.
Project description:Role of the bromodomain and extraterminal motif (BET) protein BRD2 in CTCF chromatin occupancy, tested by CRISPR/Cas9-mediated depletion of BRD2 in GATA1-null erythroblasts expressing an inducible GATA1-ER fusion (G1E-ER4). Pharmacologic inhibitors of the BET (bromodomain and extraterminal motif) family of proteins are being explored for the treatment of various diseases, including cancer, yet the individual functions of BET proteins remain unclear. Here we find that BRD2 co-localizes with the architectural/insulator protein CCCTC-binding factor (CTCF) genome-wide. CTCF recruits BRD2 to co-bound sites, whereas BRD2 is dispensable for CTCF occupancy. Genome editing at a CTCF/BRD2 co-occupied site reveals a functional boundary element that upon perturbation results in transcriptional misregulation. Single-molecule RNA FISH reveals that either site-specific CTCF loss or BRD2 depletion increases the correlation in expression of two genes flanking the boundary. Together these findings indicate that BRD2 supports chromatin boundary activity in a CTCF-dependent manner and suggest that pharmacologic BET inhibitors influence gene expression in part by perturbing chromatin domain boundary function.
Project description:We analyzed a role of Brd2 protein in transcription and alternative splicing. 289 genes change alternative splicing after Brd2 knockdown and 1459 genes alter gene expression compared to cells treated with negative control siRNA. 6 samples (3 independent samples of cells treated with Brd2 siRNA, 3 samples of cells treated with negative control siRNA)
Project description:The dual bromodomain protein Brd2 is closely related to the basal transcription factor TAFII250, which is essential for cyclin A transactivation and mammalian cell cycle progression. In transgenic mice, constitutive lymphoid expression of Brd2 causes a malignancy most similar to human diffuse large B cell lymphoma. We compare the genome-wide transcriptional expression profiles of these lymphomas with those of proliferating and resting normal B cells. Transgenic tumors reproducibly show differential expression of a large number of genes important for cell cycle control and lymphocyte biology; expression patterns are either tumor-specific or proliferation-specific. Several of their human orthologs have been implicated in human lymphomagenesis. Others correlate with human disease survival time. BRD2 is underexpressed in some subtypes of human lymphoma and these subtypes display a number of similarities to the BRD2-mediated murine tumors. We illustrate with a high degree of detail that cancer is more than rampant cellular proliferation, but involves the additional transcriptional mobilization of many genes, some of them poorly characterized, which show a tumor-specific pattern of gene expression. Experiment Overall Design: 26 samples are included in this series. Sporadic murine E-mu-BRD2 mediated lymphomas are divided into three classes by disease severity and compared to either resting or mitogen-activated B Cells. The resting and activated B Cells are either wildtype or E-mu-BRD2 transgenic. All samples are on the FVB wildtype background.
Project description:The bromodomain and extra-terminal domain (BET) proteins are known as drug targets in diseases. However, the BET protein association profile to histone H4 hyperacetylation is not well understood and BET inhibition effects have been studied more in the context of BRD4 than BRD2. Here, by integrating chromatin and transcriptome analyses of ChIP-seq and Cap Analysis Gene Expression (CAGE) datasets, we show that di-acetylation at K5 and K8 of histone H4 (H4K5acK8ac) co-localizes with H3K27ac and BRD2 in the majority of active enhancers and promoters, where BRD2 has a stronger association with H4K5acK8ac than H3K27ac. Interestingly, although BET inhibition by JQ1 led to complete reduction of BRD2 binding, only local changes of H4K5acK8ac were observed and surprisingly a remarkable number of BRD2-bound genes including MYC and its target genes were upregulated. Using BRD2-enriched sites and transcriptional activity analysis, we identified candidate transcription factors (TFs) potentially involved in the JQ1 response in BRD2-dependent and independent manner.