Nibrin, a ~95 kDa double stranded DNA repair protein,Is mutated in Nijmegen breakage syndrome (NBS). Patients with NBS exhibit chromosomal instability, resulting in hypersensitivity to irradiation and cancer predisposition. Nibrin forms a manganese-sensitive complex with hMre11 and hRAD50 that has single strand DNA endonuclease and exonuclease activities and is likely to be important for DNA excision, repair, and stability. This nibrin/Mre11/RAD50 complex is inhibited by BRCA1. The ATM (ataxia telangiectasia mutated) kinase has been shown to phosphorylate nibrin in an S-phase checkpoint pathway. Nibrin levels are elevated in testis tissue, suggesting a possible role in meiotic recombination. Nibrin may also be involved in telomere length maintenance.
NBN; nibrin; NBS, NBS1, Nijmegen breakage syndrome 1 (nibrin); AT V1; AT V2; ATV; cell cycle regulatory protein p95; Nijmegen breakage syndrome 1 (nibrin); p95 protein of the MRE11/RAD50 complex; NBS; P95; NBS1; AT-V1; AT-V2; FLJ10155; MGC87362; nijmegen breakage syndrome protein 1 homolog; im:6911679; zgc:194152