53BP1 is required for class switch recombination

Irene M. Ward, Bernardo Reina-San-Martin, Alexandru Olaru, Kay Minn, Koji Tamada, Julie S. Lau, Marilia Cascalho, Lieping Chen, Andre Nussenzweig, Ferenc Livak, Michel C. Nussenzweig, Junjie Chen

Research output: Contribution to journalArticle


53BP1 participates early in the DNA damage response and is involved in cell cycle checkpoint control. Moreover, the phenotype of mice and cells deficient in 53BP1 suggests a defect in DNA repair (Ward et al., 2003b). Therefore, we asked whether or not 53BP1 would be required for the efficient repair of DNA double strand breaks. Our data indicate that homologous recombination by gene conversion does not depend on 53BP1. Moreover, 53BP1-deficient mice support normal V(D)J recombination, indicating that 53BP1 is not required for "classic" non-homologous end joining. However, class switch recombination is severely impaired in the absence of 53BP1, suggesting that 53BP1 facilitates DNA end joining in a way that is not required or redundant for the efficient closing of RAG-induced strand breaks. These findings are similar to those observed in mice or cells deficient in the tumor suppressors ATM and H2AX, further suggesting that the functions of ATM, H2AX, and 53BP1 are closely linked.

Original languageEnglish (US)
Pages (from-to)459-464
Number of pages6
JournalJournal of Cell Biology
Issue number4
StatePublished - May 24 2004
Externally publishedYes


  • ATM
  • DNA repair
  • H2AX
  • NHEJ
  • V(D)J recombination

ASJC Scopus subject areas

  • Cell Biology

Fingerprint Dive into the research topics of '53BP1 is required for class switch recombination'. Together they form a unique fingerprint.

  • Cite this

    Ward, I. M., Reina-San-Martin, B., Olaru, A., Minn, K., Tamada, K., Lau, J. S., Cascalho, M., Chen, L., Nussenzweig, A., Livak, F., Nussenzweig, M. C., & Chen, J. (2004). 53BP1 is required for class switch recombination. Journal of Cell Biology, 165(4), 459-464. https://doi.org/10.1083/jcb.200403021