53BP1 facilitates long-range DNA end-joining during V(D)J recombination

Academic Article


  • Variable, diversity and joining (V(D)J) recombination and class-switch recombination use overlapping but distinct non-homologous end joining pathways to repair DNA double-strand-break intermediates. 53BP1 is a DNA-damage-response protein that is rapidly recruited to sites of chromosomal double-strand breaks, where it seems to function in a subset of ataxia telangiectasia mutated (ATM) kinase-, H2A histone family member X (H2AX, also known as H2AFX)- and mediator of DNA damage checkpoint 1 (MDC1)-dependent events. A 53BP1-dependent end-joining pathway has been described that is dispensable for V(D)J recombination but essential for class-switch recombination. Here we report a previously unrecognized defect in the joining phase of V(D)J recombination in 53BP1-deficient lymphocytes that is distinct from that found in classical non-homologous-end-joining-, H2ax-, Mdc1- and Atm-deficient mice. Absence of 53BP1 leads to impairment of distal V-DJ joining with extensive degradation of unrepaired coding ends and episomal signal joint reintegration at V(D)J junctions. This results in apoptosis, loss of T-cell receptor α locus integrity and lymphopenia. Further impairment of the apoptotic checkpoint causes propagation of lymphocytes that have antigen receptor breaks. These data suggest a more general role for 53BP1 in maintaining genomic stability during long-range joining of DNA breaks. ©2008 Macmillan Publishers Limited. All rights reserved.
  • Authors

    Published In

  • Nature  Journal
  • Digital Object Identifier (doi)

    Author List

  • Difilippantonio S; Gapud E; Wong N; Huang CY; Mahowald G; Chen HT; Kruhlak MJ; Callen E; Livak F; Nussenzweig MC
  • Start Page

  • 529
  • End Page

  • 533
  • Volume

  • 456
  • Issue

  • 7221