RAD23A
Description
The RAD23A (RAD23 homolog A, nucleotide excision repair protein) is a protein-coding gene located on chromosome 19.
RAD23A is a human protein encoded by the RAD23A gene. It is one of two human homologs of the yeast protein Rad23, which is involved in nucleotide excision repair (NER). RAD23A has been shown to interact with and enhance the activity of 3-methyladenine-DNA glycosylase (MPG), suggesting a role in DNA damage recognition during base excision repair. The protein contains an N-terminal ubiquitin-like domain that interacts with the 26S proteasome and ubiquitin protein ligase E6AP, indicating a potential role in the ubiquitin-mediated proteolytic pathway. RAD23A has been found to interact with Ataxin 3, PSMD4, and Sequestosome 1.
RAD23A acts as a multiubiquitin chain receptor, playing a role in regulating the breakdown of proteins by the proteasome. It specifically binds to 'Lys-48'-linked polyubiquitin chains, with a preference for longer chains, and also binds, albeit with lower affinity, to 'Lys-63'-linked polyubiquitin chains. RAD23A is thought to be able to bind both the 26S proteasome and polyubiquitinated substrates simultaneously, facilitating the delivery of ubiquitinated proteins to the proteasome for degradation.
RAD23A is also known as HHR23A, HR23A.
