The chromatin remodeler Brg1 activates enhancer repertoires to establish B cell identity and modulate cell growth

Nat Immunol. 2015 Jul;16(7):775-84. doi: 10.1038/ni.3170. Epub 2015 May 18.

Abstract

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 progenitor cells, the chromatin remodeler Brg1 specified the B cell fate. In committed pro-B cells, Brg1 regulated contraction of the locus encoding the immunoglobulin heavy chain (Igh) and controlled expression of the gene encoding the transcription factor c-Myc (Myc) to modulate the expression of genes encoding products that regulate ribosome biogenesis. In committed pro-B cells, Brg1 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 enhancer repertoires.

MeSH terms

  • Animals
  • B-Lymphocytes / immunology*
  • B-Lymphocytes / metabolism
  • Cell Differentiation / genetics
  • Cell Differentiation / immunology
  • Cell Lineage / genetics
  • Cell Lineage / immunology
  • Cell Proliferation*
  • Cells, Cultured
  • Chromatin Assembly and Disassembly / genetics
  • Chromatin Assembly and Disassembly / immunology
  • DNA Helicases / genetics
  • DNA Helicases / immunology*
  • DNA Helicases / metabolism
  • Enhancer Elements, Genetic / genetics
  • Enhancer Elements, Genetic / immunology*
  • Flow Cytometry
  • Gene Expression Regulation / genetics
  • Gene Expression Regulation / immunology
  • Immunoglobulin Heavy Chains / genetics
  • Immunoglobulin Heavy Chains / immunology
  • Immunoglobulin Heavy Chains / metabolism
  • In Situ Hybridization, Fluorescence
  • Mice, Knockout
  • Mice, Transgenic
  • Nuclear Proteins / genetics
  • Nuclear Proteins / immunology*
  • Nuclear Proteins / metabolism
  • Precursor Cells, B-Lymphoid / immunology
  • Precursor Cells, B-Lymphoid / metabolism
  • Protein Binding / immunology
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / immunology
  • Proto-Oncogene Proteins c-myc / metabolism
  • RNA Interference / immunology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Factors / genetics
  • Transcription Factors / immunology*
  • Transcription Factors / metabolism

Substances

  • Immunoglobulin Heavy Chains
  • Nuclear Proteins
  • Proto-Oncogene Proteins c-myc
  • Transcription Factors
  • Smarca4 protein, mouse
  • DNA Helicases

Associated data

  • GEO/GSE66978