ATR Recombinant Rabbit mAb (S-3506-59)

ATR (Ataxia Telangiectasia and Rad3-related) protein is a serine/threonine kinase that serves as a master regulator of the DNA damage response (DDR), particularly in response to replication stress and DNA double-strand breaks; it is recruited to sites of DNA damage through its interaction with RPA-coated single-stranded DNA (ssDNA) and the Rad9-Rad1-Hus1 (9-1-1) clamp complex, whereupon it phosphorylates key downstream substrates including the checkpoint kinase Chk1, p53, BRCA1, and RAD51 to initiate cell cycle arrest, facilitate DNA repair, and prevent replication fork collapse, thereby maintaining genomic integrity and preventing tumorigenesis, with its dysregulation being implicated in various cancers and its inhibition emerging as a promising therapeutic strategy for cancer treatment.