title: DNA end-joining catalyzed by human cell-free extracts.
abstract: Mammalian cells defective in DNA end-joining are highly sensitive to ionizing radiation and are immunodeficient because of a failure to complete V(D)J recombination. By using cell-free extracts prepared from human lymphoblastoid cell lines, an in vitro system for end-joining has been developed. Intermolecular ligation was found to be accurate and to depend on DNA ligase IV/Xrcc4 and requires Ku70, Ku86, and DNA-PKcs, the three subunits of the DNA-activated protein kinase DNA-PK. Because these activities are involved in the cellular resistance to x-irradiation and V(D)J recombination, the development of this in vitro system provides an important advance in the study of the mechanism of DNA end-joining in human cells.
authors.affiliation: Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, United Kingdom.
authors.forename: P
authors.initials: P
authors.lastname: Baumann
authors.forename: S C
authors.initials: SC
authors.lastname: West
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D034961:Antigens, Nuclear; D002384:Catalysis; D002460:Cell Line; D002474:Cell-Free System; D002867:Chromones / Q000494:pharmacology; D004247:DNA / Q000378:metabolism*; D004265:DNA Helicases; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000378:metabolism; D004260:DNA Repair; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D000072200:Ku Autoantigen; D046911:Macromolecular Substances; D009025:Morpholines / Q000494:pharmacology; D009687:Nuclear Proteins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D034961:Antigens, Nuclear; D002867:Chromones; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; C000607893:LIG4 protein, human; D046911:Macromolecular Substances; D009025:Morpholines; D009687:Nuclear Proteins; C101467:XRCC4 protein, human; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D004247:DNA; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; D017346:Protein Serine-Threonine Kinases; D004265:DNA Helicases; C106893:XRCC5 protein, human; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen; D011088:DNA Ligases; D000072481:DNA Ligase ATP; D000077191:Wortmannin