XRCC1
Description
The XRCC1 (X-ray repair cross complementing 1) is a protein-coding gene located on chromosome 19.
XRCC1, also known as X-ray repair cross-complementing protein 1, is a protein that in humans is encoded by the XRCC1 gene. XRCC1 is involved in DNA repair, where it complexes with DNA ligase III. XRCC1 is involved in the efficient repair of DNA single-strand breaks formed by exposure to ionizing radiation and alkylating agents. This protein interacts with DNA ligase III, polymerase beta and poly (ADP-ribose) polymerase to participate in the base excision repair pathway. It may play a role in DNA processing during meiogenesis, i.e. during the induction of meiosis and recombination in germ cells. A rare microsatellite polymorphism in this gene is associated with cancer in patients of varying radiosensitivity. The XRCC1 protein does not have enzymatic activity, but acts as a scaffolding protein that interacts with multiple repair enzymes. The scaffolding allows these repair enzymes to then carry out their enzymatic steps in repairing DNA. XRCC1 is involved in single-strand break repair, base excision repair and nucleotide excision repair. As reviewed by London, XRCC1 protein has three globular domains connected by two linker segments of ~150 and 120 residues. The XRCC1 N-terminal domain binds to DNA polymerase beta, the C-terminal BRCT domain interacts with DNA ligase III alpha and the central domain contains a poly(ADP-ribose) binding motif.
XRCC1 is involved in DNA single-strand break repair by mediating the assembly of DNA break repair protein complexes (PubMed:11163244, PubMed:28002403). XRCC1 negatively regulates the ADP-ribosyltransferase activity of PARP1 during base-excision repair in order to prevent excessive PARP1 activity (PubMed:34102106, PubMed:34811483, PubMed:28002403). XRCC1 recognizes and binds poly-ADP-ribose chains: specifically binds auto-poly-ADP-ribosylated PARP1, limiting its activity (PubMed:14500814, PubMed:34102106, PubMed:34811483).
XRCC1 is also known as RCC, SCAR26.
