Damage-specific DNA-binding protein 2 (DDB2)

Damage-specific DNA-binding protein 2 (DDB2) is a nuclear protein encoded by the DDB2 (XPE) gene located on chromosome 11p12-p11 in humans. DDB2 serves as a substrate recognition subunit in the UV-DDB heterodimeric complex, pairing with DDB1 and associating with proteins such as CUL4A and PARP1 to form the E3 ubiquitin ligase complex CRL4^DDB2[3][5]. This complex is essential for the global genome nucleotide excision repair (GG-NER) pathway, rapidly detecting and binding UV-induced DNA damage such as cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts[2][5]. DDB2 also recognizes other forms of DNA damage, including abasic sites and adducts generated by chemotherapeutic agents[5]. Its functions extend to chromatin remodeling, modulating access for repair enzymes, and regulating cell cycle progression and apoptosis via interactions with p53, BRCA1, and other regulatory proteins[5][3]. Mutations in DDB2 cause the XPE form of xeroderma pigmentosum, characterized by mild dermatological symptoms and impaired DNA repair[3][5]. In cancer, DDB2 may act as a prognostic marker of therapy sensitivity and has complex roles in tumorigenesis, influencing both tumor growth and response to DNA-damaging treatments[5]. DDB2 function is regulated by post-translational modifications including ubiquitination, SUMOylation, and PARylation, and its expression can be modulated by p53 and stress-responsive signaling pathways[5][6].\n\nTo summarize, DDB2 is a multifunctional DNA damage sensor and regulatory protein relevant to both cancer therapy and inherited DNA repair disorders.

Other names

DNA damage-binding protein 2DDBbUV-DDB 2DDBBUV-DDB2FLJ34321XPEDDB p48 subunitxeroderma pigmentosum group E protein

Drugs generating bulky DNA adducts (alkylating agents, UV-mimetics): DDB2 recognizes resultant DNA lesions and promotes repair, modulating therapeutic sensitivity[5].