Nijmegen breakage syndrome protein 1 (NBN)

Nijmegen breakage syndrome protein 1 (nibrin; NBN) is a key DNA repair protein encoded by the NBN gene, functioning as a core adapter in the MRN complex together with MRE11 and RAD50[1][3]. This complex is essential for recognizing and repairing DNA double-strand breaks, activating checkpoint signaling, maintaining chromosomal stability, and promoting homologous recombination and telomere integrity[1][3]. Nibrin mediates recruitment of repair proteins to DNA damage sites, and is required for critical processes like immunoglobulin class-switch recombination in B lymphocytes[2]. Mutations in NBN cause Nijmegen breakage syndrome, an autosomal recessive disorder distinguished by microcephaly, cancer predisposition, immunodeficiency, and sensitivity to ionizing radiation[3]. Nibrin is not an enzyme or receptor, but is considered a valid therapeutic target in cancer research and genetic diagnostics[3].

Other names

NibrinNBNNBSNBS1P95hNbs1ATVAT-V2AT-V1Cell cycle regulatory protein p95p95 protein of the MRE11/RAD50 complexNijmegen breakage syndrome 1 (nibrin)