Project description:We have carried out ChIP-seq to study the distribution of Brahma in the genome of S2 cells and to identify the Brahma-bound genes. We have also knocked down Brahma by RNA interference and we have carried out RNA-seq to determine the changes induced by Brahma depletion in the transcriptome of S2 cells. Furthermore, we have carried out RNA-seq experiments to profile S2 cells in which we first deplete Brahma by RNA interference and then express recombinant Brahma (either wild-type or ATPase mutant). These datasets are being used in several projects aimed at gaining understanding on the roles of Brahma in transcription regulation and pre-mRNA processing.
Project description:SWI/SNF chromatin remodeling complexes control gene expression by regulating chromatin structure. However, the full subunit composition of SWI/SNF complexes in plants remains unclear. Here we show that BRAHMA Interacting Protein 1 (BRIP1) and BRIP2 in Arabidopsis thaliana are core subunits of plant SWI/SNF complexes. BRIP1 and 2 are two homolog proteins. brip1 brip2 double mutants exhibit developmental phenotypes and a transcriptome strikingly similar to those of BRAHMA (BRM) mutants. Genetic interaction tests indicated that BRIP1 and 2 act together with BRM to regulate gene expression. Furthermore, BRIP1 and 2 physically interact with BRM-containing SWI/SNF complexes, and extensively co-localize with BRM at endogenous genes. Loss-of-brip1brip2 results in decreased BRM occupancy at almost all BRM target genes and substantially reduced subunits incorporation into the BRM-containing SWI/SNF complexes. Together, our work identifies new core subunits of BRM-containing SWI/SNF complexes in plants, and uncovers the essential role of these subunits in regulating the integrity (assembly) of SWI/SNF complexes in plants.
