GSE66978
Brg1 activates enhancer repertoires to establish B cell identity and modulate cell growth
Early B cell development is orchestrated by the combined activities of the transcriptional regulators E2A, EBF1, Foxo1 and Ikaros. However, how the genome-wide binding patterns of these regulators are modulated during B-lineage development remains to be determined. Here, we found that in lymphoid progenitors the chromatin remodeler Brg1 specified the B cell fate. In committed pro-B cells Brg1 regulated Igh locus contraction and controlled c-Myc expression to modulate the expression of genes that regulate ribosome biogenesis. In committed pro-B cells Brg1 also suppressed a pre-B lineage-specific pattern of gene expression. Finally, we found that Brg1 acted mechanistically to establish B cell fate and modulate cell growth by facilitating access of lineage-specific transcription factors to poised enhancer repertoires. Overall design: 8 ATAC-Seq samples from sorted ALP and BLP (duplicates, control and Brg1-deleted), 4 ATAC-Seq samples from cultured pro-B cells (duplicates, control and Brg1-deleted), 2 Ikaros ChIP-seq samples (performed in Rag1-/- pro-B cells and in E2A-/- pre-pro-B cells), 1 Brg1 ChIP-seq sample and accompanying Input sample (both in Rag1-/- pro-B cells), 4 RNA-Seq samples from cultured pro-B cells (duplicates, control and Brg1-deleted), 6 RNA-Seq samples from cultured Rag1-/- pro-B cells (triplicates, control and Brg1-knock down).