RAD23B
Description
The RAD23B (RAD23 homolog B, nucleotide excision repair protein) is a protein-coding gene located on chromosome 9.
RAD23B is a human protein encoded by the RAD23B gene. It is one of two human homologs of Saccharomyces cerevisiae Rad23, a protein involved in nucleotide excision repair (NER). RAD23B is part of a protein complex that complements the NER defect of xeroderma pigmentosum group C (XP-c) cell extracts in vitro. It interacts with and enhances the activity of 3-methyladenine-DNA glycosylase (MPG), suggesting a role in DNA damage recognition in base excision repair. RAD23B contains an N-terminal ubiquitin-like domain that interacts with the 26S proteasome, potentially linking it to the ubiquitin-mediated proteolytic pathway. The XPC-RAD23B complex plays a crucial role in the initial damage recognition step of global genomic NER (GG-NER), recognizing various DNA lesions that destabilize the DNA duplex, including UV-induced photoproducts, adducts caused by environmental mutagens, and oxidative lesions. The presence of XPC-RAD23B is essential for the assembly of other core NER factors and progression through the NER pathway. RAD23B is part of a trimeric complex with centrin-2, a calcium-binding protein. The expression of RAD23B can be epigenetically repressed through promoter methylation or by microRNAs miR-744-3p or miR-373.
RAD23B is a multiubiquitin chain receptor that modulates proteasomal degradation by binding to polyubiquitin chains. It can bind to both the 26S proteasome and polyubiquitinated substrates, facilitating the delivery of ubiquitinated proteins to the proteasome. RAD23B might also participate in the endoplasmic reticulum-associated degradation (ERAD) of misfolded glycoproteins by interacting with PNGase and transporting deglycosylated proteins to the proteasome.
RAD23B is also known as HHR23B, HR23B, P58.
