This gene encodes a zinc finger protein involved in DNA excision repair. The encoded protein is part of the NER (nucleotide excision repair) complext which is responsible for repair of UV radiation-induced photoproducts and DNA adducts induced by chemical carcinogens. Mutations in this gene are associated with xeroderma pigmentosum complementation group A. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Mar 2009],disease:Defects in XPA are a cause of xeroderma pigmentosum complementation group A (XP-A) [MIM:278700]; also known as xeroderma pigmentosum type 1 (XP1). XP-A is a rare human autosomal recessive disease characterized by solar sensitivity, high predisposition for developing cancers on areas exposed to sunlight and, in some cases, neurological abnormalities. Group A patients show the most severe skin symptoms and progressive neurological disorders.,function:Involved in DNA excision repair. Initiates repair by binding to damaged sites with various affinities, depending on the photoproduct and the transcriptional state of the region. Required for UV-induced CHK1 phosphorylation and the recruitment of CEP164 to cyclobutane pyrimidine dimmers (CPD), sites of DNA damage after UV irradiation.,PTM:Phosphorylated upon DNA damage, probably by ATM or ATR.,similarity:Belongs to the XPA family.,subunit:Interacts with XAB1 and RPA1. Interacts (via N-terminus) with CEP164 upon UV irradiation.,tissue specificity:Expressed in various cell lines and in skin fibroblasts.,