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Updated: Jul 15, 2026

Immunofluorescence Microscopy of γH2AX and 53BP1 for Analyzing the Formation and Repair of DNA Double-strand Breaks
Published on: November 3, 2017
Response to RAG-mediated VDJ cleavage by NBS1 and gamma-H2AX
H T Chen1, A Bhandoola, M J Difilippantonio
1Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Abstract:
Genetic disorders affecting cellular responses to DNA damage are characterized by high rates of translocations involving antigen receptor loci and increased susceptibility to lymphoid malignancies. We report that the Nijmegen breakage syndrome protein (NBS1) and histone gamma-H2AX, which associate with irradiation-induced DNA double-strand breaks (DSBs), are also found at sites of VDJ (variable, diversity, joining) recombination-induced DSBs. In developing thymocytes, NBS1 and gamma-H2AX form nuclear foci that colocalize with the T cell receptor alpha locus in response to recombination activating gene (RAG) protein-mediated VDJ cleavage. Our results suggest that surveillance of T cell receptor recombination intermediates by NBS1 and gamma-H2AX may be important for preventing oncogenic translocations.
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