Antibodies to XRCC Proteins

X-Ray Repair Cross Complementing 1 (XRCC1) plays a role in excision repair of DNA after ionizing irradiation. XRCC1 interacts with human polynucleotide kinase (PNK), in addition to its interactions with DNA polymerase-beta (POLB) and DNA ligase III (LIG3). Moreover, these 4 proteins are coassociated in multiprotein complexes in human cell extract, and together they repair single-strand breaks typical of those induced by reactive oxygen species and ionizing radiation. Strikingly, XRCC1 stimulates the DNA kinase and DNA phosphatase activities of PNK at damaged DNA termini, thereby accelerating the overall repair reaction.

XRCC2 and XRCC3 (X-Ray Cross Complementing 2 and 3) are essential for repairing the double strand DNA breaks by homologous recombination between sister chromatids. They are homologous to Rad51. Five human homologues of RAD 51; XRCC2, XRCC3, RAD51B, RAD51C, RAD51D, interact among themselves to form one big complex or several smaller complexes.

XR-1 is a Chinese hamster ovary cell mutant that is unusually sensitive to killing by gamma rays in the G1 portion of the cell cycle but has nearly normal resistance to gamma-ray damage in late S phase. This cell cycle sensitivity correlates with the mutant's inability to repair DNA double-strand breaks produced by ionizing radiation (IR) and restriction enzymes. The human XRCC4 gene restores DNA double-strand break repair and the ability to support V(D)J recombination of transiently introduced substrates in the XR-1 CHO cell line. The corresponding gene is deleted in XR-1 cells. XRCC4 encodes a ubiquitously expressed product unrelated to any previously described protein. It was shown, that differentiating lymphocytes and neurons strictly require the XRCC4 and DNA ligase IV end-joining proteins.

Ku proteins are nuclear proteins found in eukaryotes. They exist as a heterodimer consisiting of Ku 70 (also known as DNA-repair protein XRCC6) and Ku 80 (DNA-repair protein XRCC5), migrating at approximately 70 and 80 kDa respectively. They bind to DNA ends at double strand breaks. The Ku proteins interact with the DNA-dependent protein kinase (DNA-PK) and participate in the targeting of DNA-PK to DNA. The Ku proteins may participate in numerous cellular processes, including DNA repair and replication, cell signalling, cell proliferation, transcriptional activation and apoptosis.

DNA PK (PRKDC, Mouse gene Xrcc7) is the key component of the non-homologous end-joining (NHEJ) pathway of double-strand break (DSB) repair in mammalian cells. DNA PK consists of a heterodimeric DNA-binding subunit (Ku70/80) and an approximately 465 kDa catalytic subunit (DNA PKcs). DNA PKcs is a serine/threonine protein kinase whose activity is greatly stimulated by its recruitment to DNA breaks by the Ku heterodimer.

Defects in DNA-repair protein XRCC9 (FANCG) are a cause of Fanconi anemia which is a genetically heterogeneous, autosomal recessive disorder characterized by progressive pancytopenia, a diverse assortment of congenital malformations, and a predisposition to the development of malignancies. At the cellular level it is associated with hypersensitivity to DNA-damaging agents, chromosomal instability (increased chromosome breakage), and defective DNA repair.

Antibody Tools for the Detection of XRCC

Acris Antibodies offers a panel of antibodies for the detection of XRCC proteins. Antibodies can be used for immunohistochemistry, western blotting and other immunological methods.

Available Antibody Panel to XRCC DNA-repair Proteins

Anti- XRCC1, XRCC2, XRCC3, XRCC4, XRCC5 (Ku80, Ku86, TLAA, CTCBF), XRCC6 (Ku70, TLAA, CTCBF), DNA-PKcs (PRKDC, HYRC, XRCC7), and XRCC9 (FANCG) antibody