XPA (D9U5U) Rabbit mAb #14607

Nucleotide excision repair (NER) is a process by which cells identify and repair DNA lesions that result from chemical and radiation exposure (1). The DNA binding protein XPA is an essential part of a pre-incision complex that forms at sites of damage, and is necessary for the initiation of nucleotide excision repair (2). XPA is one of eight NER proteins (XPA-G, XPV) encoded by genes that are defective in cases of xeroderma pigmentosum, a disorder characterized by sensitivity to sunlight, predisposition to exposed tissue cancers, and neurological defects in some patients (3). Activation of XPA follows phosphorylation at Ser196 and results in increased NER activity. Phosphorylation of XPA at Ser196 is induced by UV exposure in an ATR-dependant fashion (4) and promotes nuclear accumulation of XPA (5). Research studies suggest that XPA may be a direct substrate of the serine/threonine kinase ATR (4) and that NER activity may be negatively regulated through dephosphorylation of Ser196 by the phosphatase WIP1 (6).