title: XRCC1 coordinates disparate responses and multiprotein repair complexes depending on the nature and context of the DNA damage.
abstract: XRCC1 is a scaffold protein capable of interacting with several DNA repair proteins. Here we provide evidence for the presence of XRCC1 in different complexes of sizes from 200 to 1500 kDa, and we show that immunoprecipitates using XRCC1 as bait are capable of complete repair of AP sites via both short patch (SP) and long patch (LP) base excision repair (BER). We show that POLβ and PNK colocalize with XRCC1 in replication foci and that POLβ and PNK, but not PCNA, colocalize with constitutively present XRCC1-foci as well as damage-induced foci when low doses of a DNA-damaging agent are applied. We demonstrate that the laser dose used for introducing DNA damage determines the repertoire of DNA repair proteins recruited. Furthermore, we demonstrate that recruitment of POLβ and PNK to regions irradiated with low laser dose requires XRCC1 and that inhibition of PARylation by PARP-inhibitors only slightly reduces the recruitment of XRCC1, PNK, or POLβ to sites of DNA damage. Recruitment of PCNA and FEN-1 requires higher doses of irradiation and is enhanced by XRCC1, as well as by accumulation of PARP-1 at the site of DNA damage. These data improve our understanding of recruitment of BER proteins to sites of DNA damage and provide evidence for a role of XRCC1 in the organization of BER into multiprotein complexes of different sizes.
authors.affiliation: Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim.
authors.forename: Audun
authors.initials: A
authors.lastname: Hanssen-Bauer
authors.forename: Karin
authors.initials: K
authors.lastname: Solvang-Garten
authors.forename: Ottar
authors.initials: O
authors.lastname: Sundheim
authors.forename: Javier
authors.initials: J
authors.lastname: Peña-Diaz
authors.forename: Sonja
authors.initials: S
authors.lastname: Andersen
authors.forename: Geir
authors.initials: G
authors.lastname: Slupphaug
authors.forename: Hans E
authors.initials: HE
authors.lastname: Krokan
authors.forename: David M
authors.initials: DM
authors.lastname: Wilson
authors.forename: Mansour
authors.initials: M
authors.lastname: Akbari
authors.forename: Marit
authors.initials: M
authors.lastname: Otterlei
mesh_terms: D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D018929:Cell Culture Techniques; D006224:Cricetinae; D003412:Cricetulus; D053904:DNA Breaks, Single-Stranded / Q000528:radiation effects; D019951:DNA Polymerase beta / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004307:Dose-Response Relationship, Radiation; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D007834:Lasers; D018613:Microscopy, Confocal; D008954:Models, Biological; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics / Q000378:metabolism; D011116:Polynucleotide 5'-Hydroxyl-Kinase / Q000235:genetics / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D004268:DNA-Binding Proteins; D018809:Proliferating Cell Nuclear Antigen; D011993:Recombinant Fusion Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D011116:Polynucleotide 5'-Hydroxyl-Kinase; D019951:DNA Polymerase beta