The RAG-2 Inhibitory Domain Gates Accessibility of the V(D)J Recombinase to Chromatin

Mol Cell Biol. 2018 Jul 16;38(15):e00159-18. doi: 10.1128/MCB.00159-18. Print 2018 Aug 1.

Abstract

Accessibility of antigen receptor loci to RAG is correlated with the presence of H3K4me3, which binds to a plant homeodomain (PHD) in the RAG-2 subunit and promotes V(D)J recombination. A point mutation in the PHD, W453A, eliminates binding of H3K4me3 and impairs recombination. The debilitating effect of the W453A mutation is ameliorated by second-site mutations that locate an inhibitory domain in the interval from residues 352 through 405 of RAG-2. Disruption of the inhibitory domain stimulates V(D)J recombination within extrachromosomal substrates and at endogenous antigen receptor loci. Association of RAG-1 and RAG-2 with chromatin at the IgH locus in B cell progenitors is dependent on recognition of H3K4me3 by the PHD. Strikingly, disruption of the inhibitory domain permits association of RAG with the IgH locus in the absence of H3K4me3 binding. Thus, the inhibitory domain acts as a gate that prohibits RAG from accessing the IgH locus unless RAG-2 is engaged by H3K4me3.

Keywords: V(D)J recombination; epigenetic control; histone modification; lymphocyte development.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Adaptive Immunity
  • Allosteric Regulation
  • Amino Acid Substitution
  • Animals
  • Cell Line
  • Chromatin / metabolism*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Rearrangement, B-Lymphocyte, Heavy Chain
  • Genes, Immunoglobulin Heavy Chain
  • HEK293 Cells
  • Histone Code
  • Humans
  • Mice
  • Models, Immunological
  • NIH 3T3 Cells
  • Point Mutation
  • Precursor Cells, B-Lymphoid / immunology
  • Precursor Cells, B-Lymphoid / metabolism
  • Protein Domains
  • VDJ Recombinases / metabolism*

Substances

  • Chromatin
  • DNA-Binding Proteins
  • Rag2 protein, mouse
  • VDJ Recombinases