title: Physical and functional interaction between DNA ligase IIIalpha and poly(ADP-Ribose) polymerase 1 in DNA single-strand break repair.
abstract: The repair of DNA single-strand breaks in mammalian cells is mediated by poly(ADP-ribose) polymerase 1 (PARP-1), DNA ligase IIIalpha, and XRCC1. Since these proteins are not found in lower eukaryotes, this DNA repair pathway plays a unique role in maintaining genome stability in more complex organisms. XRCC1 not only forms a stable complex with DNA ligase IIIalpha but also interacts with several other DNA repair factors. Here we have used affinity chromatography to identify proteins that associate with DNA ligase III. PARP-1 binds directly to an N-terminal region of DNA ligase III immediately adjacent to its zinc finger. In further studies, we have shown that DNA ligase III also binds directly to poly(ADP-ribose) and preferentially associates with poly(ADP-ribosyl)ated PARP-1 in vitro and in vivo. Our biochemical studies have revealed that the zinc finger of DNA ligase III increases DNA joining in the presence of either poly(ADP-ribosyl)ated PARP-1 or poly(ADP-ribose). This provides a mechanism for the recruitment of the DNA ligase IIIalpha-XRCC1 complex to in vivo DNA single-strand breaks and suggests that the zinc finger of DNA ligase III enables this complex and associated repair factors to locate the strand break in the presence of the negatively charged poly(ADP-ribose) polymer.
authors.affiliation: Department of Molecular Medicine, Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245, USA.
authors.forename: John B
authors.initials: JB
authors.lastname: Leppard
authors.forename: Zhiwan
authors.initials: Z
authors.lastname: Dong
authors.forename: Zachary B
authors.initials: ZB
authors.lastname: Mackey
authors.forename: Alan E
authors.initials: AE
authors.lastname: Tomkinson
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D004249:DNA Damage; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000737:chemistry / Q000378:metabolism*; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D013058:Mass Spectrometry; D010957:Plasmids / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D000075223:Poly-ADP-Ribose Binding Proteins; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013347:Subcellular Fractions; D020349:Surface Plasmon Resonance; D013997:Time Factors; D020798:Two-Hybrid System Techniques; D000076105:X-ray Repair Cross Complementing Protein 1; D029867:Xenopus Proteins
chemical_list: D004268:DNA-Binding Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; D011993:Recombinant Fusion Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human; D029867:Xenopus Proteins; D011065:Poly(ADP-ribose) Polymerases; D005982:Glutathione Transferase; D003850:Deoxyribonuclease I; D011088:DNA Ligases; D000072481:DNA Ligase ATP; C000618816:DNA ligase III alpha protein, Xenopus; C000618817:LIG3 protein, human