RAD23 Homolog A (RAD23A)

RAD23A is one of two human homologs of Saccharomyces cerevisiae Rad23, a protein involved in nucleotide excision repair (NER). This protein was shown to interact with, and elevate the nucleotide excision activity of 3-methyladenine-DNA glycosylase (MPG), which suggested a role in DNA damage recognition in base excision repair. This protein contains an N-terminal ubiquitin-like domain, which was reported to interact with 26S proteasome, as well as with ubiquitin protein ligase E6AP, and thus suggests that this protein may be involved in the ubiquitin mediated proteolytic pathway in cells. The 125-kD subunit represented the previously reported XPC gene product, which represents the human homolog of the nucleotide excision repair (NER) gene RAD4 of Saccharomyces cerevisiae.