Human Phospho-Nbs1 (S343) Alexa Fluor® 405-conjugated Antibody

The Nijmegen Breakage Syndrome 1 (Nbs1) protein is a member of the Mre11/Rad50/Nbs1 (MRN) protein complex that binds to DNA double-strand breaks in cells exposed to DNA damaging agents. In addition, the MRN complex colocalizes with replication forks during DNA replication. The MRN complex plays an important role in routine cell cycle progression and genotoxic stress responses by facilitating DNA repair. Nbs1 is phosphorylated at S343 by ATM in response to double-strand breaks and by ATR under replication stress. This phosphorylation triggers the inactivation of late origin firing, which is essential for mediating the intra-S-phase checkpoint. Mutation of the nbs1 gene and resultant loss of Nbs1 protein expression in humans results in the chromosomal instability disease, Nijmegen Breakage Syndrome.