DDB1 rabbit antibody (pAb)

DDB1 (DNA damage-binding protein 1, HBV X-associated protein 1, XAP-1, Xeroderma pigmentosum group E-complementing protein) is a DNA binding protein that associates with DNA following UV damage and functions in excision repair. In addition to its function in DNA repair, DDB1 plays a role in normal mitotic exit by regulating Anaphase Promoting Complex (APC) activity. Depletion of DDB1 in mitotic cells significantly delays mitotic exit. DDB1 facilitates the binding of substrates to the Cul4-Roc1 complex and the ubiquitination of selected proteins, including histones H2A, H3 and H4 localized to the sites of DNA damage. It is also involved in PCNA-dependent polyubiquitination of CDT1 and MDM2-dependent ubiquitination of P53 in response to radiation-induced DNA damage and during DNA replication. In mouse studies, it was identified that loss of DDB1 function prevents hepatocytes from replicating DNA, inducing compensatory proliferation of normal hepatocytes that leads to development of hepatocellular carcinoma.