title: Translocation of XRCC1 and DNA ligase IIIalpha from centrosomes to chromosomes in response to DNA damage in mitotic human cells.
abstract: DNA single-strand breaks (SSBs) are the most frequent lesions caused by oxidative DNA damage. They disrupt DNA replication, give rise to double-strand breaks and lead to cell death and genomic instability. It has been shown that the XRCC1 protein plays a key role in SSBs repair. We have recently shown in living human cells that XRCC1 accumulates at SSBs in a fully poly(ADP-ribose) (PAR) synthesis-dependent manner and that the accumulation of XRCC1 at SSBs is essential for further repair processes. Here, we show that XRCC1 and its partner protein, DNA ligase IIIalpha, localize at the centrosomes and their vicinity in metaphase cells and disappear during anaphase. Although the function of these proteins in centrosomes during metaphase is unknown, this centrosomal localization is PAR-dependent, because neither of the proteins is observed in the centrosomes in the presence of PAR polymerase inhibitors. On treatment of metaphase cells with H2O2, XRCC1 and DNA ligase IIIalpha translocate immediately from the centrosomes to mitotic chromosomes. These results show for the first time that the repair of SSBs is present in the early mitotic chromosomes and that there is a dynamic response of XRCC1 and DNA ligase IIIalpha to SSBs, in which these proteins are recruited from the centrosomes, where metaphase-dependent activation of PAR polymerase occurs, to mitotic chromosomes, by SSBs-dependent activation of PAR polymerase.
authors.affiliation: Department of Molecular Genetics, Institute of Development, Aging and Cancer, Tohoku University 980-8575 Sendai, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okano
authors.forename: Li
authors.initials: L
authors.lastname: Lan
authors.forename: Alan E
authors.initials: AE
authors.lastname: Tomkinson
authors.forename: Akira
authors.initials: A
authors.lastname: Yasui
mesh_terms: D002460:Cell Line; D018385:Centrosome / Q000737:chemistry / Q000378:metabolism*; D002877:Chromosomes, Human / Q000378:metabolism*; D004249:DNA Damage; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000032:analysis / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D008938:Mitosis; D011064:Poly Adenosine Diphosphate Ribose / Q000096:biosynthesis; D000075223:Poly-ADP-Ribose Binding Proteins; D021381:Protein Transport; D000076105:X-ray Repair Cross Complementing Protein 1; D029867:Xenopus Proteins
chemical_list: D004268:DNA-Binding Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human; D029867:Xenopus Proteins; D011064:Poly Adenosine Diphosphate Ribose; D006861:Hydrogen Peroxide; D011088:DNA Ligases; D000072481:DNA Ligase ATP; C000618816:DNA ligase III alpha protein, Xenopus