Project description:We found binding of the remodeling protein BRG1 was programmed by lineage and activation signals. BRG1 binding was positively correlated with gene activity at protein-coding and miRNA genes. BRG1 binding was found at promoters and distal regions, including known and novel distal regulatory elements. Distal BRG1 binding correlated with expression, and novel distal sites possessed enhancer activity, suggesting a general role for BRG1 in long-distance gene regulation. Together, these findings suggest BRG1 interprets differentiation and activation signals and plays a causal role in gene regulation, chromatin structure, and cell fate. Our findings indicate BRG1 binding is a useful marker for identifying cis-regulatory regions in protein-coding and miRNA genes. Compare BRG1 binding in T helper subsets genome wide; Naïve, resting Th1, resting Th2, Stimulated Th1, Stimulated Th2, Stimulated Th17, compared to input DNA as negative control
Project description:We found binding of the remodeling protein BRG1 was programmed by lineage and activation signals. BRG1 binding was positively correlated with gene activity at protein-coding and miRNA genes. BRG1 binding was found at promoters and distal regions, including known and novel distal regulatory elements. Distal BRG1 binding correlated with expression, and novel distal sites possessed enhancer activity, suggesting a general role for BRG1 in long-distance gene regulation. Together, these findings suggest BRG1 interprets differentiation and activation signals and plays a causal role in gene regulation, chromatin structure, and cell fate. Our findings indicate BRG1 binding is a useful marker for identifying cis-regulatory regions in protein-coding and miRNA genes.
Project description:The SWI/SNF complex remodels chromatin in an ATP-dependent manner through the ATPase subunits BRG1 and BRM. Chromatin remodeling alters nucleosome structure to change gene expression, however aberrant remodeling and gene expression can result in cancer. The function and localization on chromatin of the SWI/SNF complex depends on the protein makeup of the complex. Here we report the protein-protein interactions of wild-type BRG1 or mutant BRG1 in which the HSA domain has been deleted (BRG1-HSA). We demonstrate the interaction of BRG1 with most SWI/SNF complex members and a failure of a number of these members to interact with BRG1-HSA. These results demonstrate that the HSA domain of BRG1 is a critical interaction platform for the correct formation of SWI/SNF remodeling complexes.
Project description:Turnover and exchange of nucleosomal histones and their variants, a process long believed to be static in post-replicative cells, remains largely unexplored in brain. Here, we describe a novel mechanistic role for HIRA (histone cell cycle regulator) and proteasomal degradation associated histone dynamics in the regulation of activity-dependent transcription, synaptic connectivity and behavior. We uncover a dramatic developmental profile of nucleosome occupancy across the lifespan of both rodents and humans, with the histone variant H3.3 accumulating to near saturating levels throughout the neuronal genome by mid-adolescence. Despite such accumulation, H3.3 containing nucleosomes remain highly dynamic–in a modification independent manner–to control neuronal- and glial- specific gene expression patterns throughout life. Manipulating H3.3 dynamics in both embryonic and adult neurons confirmed its essential role in neuronal plasticity and cognition. Our findings establish histone turnover as a critical, and previously undocumented, regulator of cell-type specific transcription and plasticity in mammalian brain. All ChIP-seq samples were generated to test the impact of neuronal activity/adult physiological plasticity on histone turnover in the central nervous system. This was tested in cultured neurons and astrocytes, FACS purified neurons or FACS purified Glia.
