RAD23B

RAD23B

RAD23B is a human gene that encodes a protein involved in the nucleotide excision repair (NER) pathway, which is crucial for repairing DNA damage caused by ultraviolet (UV) light and other mutagens. The RAD23B protein is a part of the ubiquitin-proteasome system and plays a significant role in maintaining genomic stability.

Structure

The RAD23B gene is located on chromosome 9 in humans. The protein encoded by this gene contains a ubiquitin-like (UBL) domain at the N-terminus and two ubiquitin-associated (UBA) domains. These domains are essential for its interaction with other proteins involved in DNA repair and protein degradation pathways.

Function

RAD23B is primarily involved in the nucleotide excision repair pathway. It functions by recognizing and binding to damaged DNA sites, facilitating the recruitment of other NER factors to the site of damage. RAD23B, in complex with XPC, forms the XPC-RAD23B complex, which is crucial for the initial damage recognition step in NER.

In addition to its role in DNA repair, RAD23B is also involved in the ubiquitin-proteasome system. It acts as a shuttle factor, delivering ubiquitinated proteins to the proteasome for degradation. This function is mediated by its UBL and UBA domains, which interact with ubiquitin and the proteasome, respectively.

Clinical Significance

Mutations or dysregulation of RAD23B can lead to impaired DNA repair, contributing to genomic instability and increasing the risk of cancer development. Studies have shown that RAD23B expression levels can be altered in various cancers, making it a potential biomarker for cancer diagnosis and prognosis.

Research

Ongoing research is focused on understanding the detailed mechanisms of RAD23B in DNA repair and its interactions with other proteins in the NER pathway. There is also interest in exploring RAD23B as a therapeutic target for enhancing DNA repair in cancer cells, potentially improving the efficacy of chemotherapy and radiotherapy.

Also see

• Nucleotide excision repair
• Ubiquitin-proteasome system
• XPC
• DNA repair
• Genomic stability