title: Binding of Ku and c-Abl at the kinase homology region of DNA-dependent protein kinase catalytic subunit.
abstract: The DNA-dependent protein kinase (DNA-PK) controls the repair of double-stranded DNA breaks in mammalian cells. The protein kinase subunit of DNA-PK (DNA-PKcs) is targeted to DNA breaks by association with the Ku DNA-binding heterodimer. Here we show that a Ku association site is present at the carboxyl terminus of DNA-PKcs (amino acids 3002-3850) near the protein kinase domain. Correspondingly, the nuclear c-Abl tyrosine kinase that associates with DNA-PK also binds to the kinase homology domain. The c-Abl SH3 domain binds to amino acids 3414-3850 of DNA-PKcs. c-Abl phosphorylates C-terminal fragments of DNA-PKcs, particularly amino acids 3414-3850. c-Abl phosphorylation of DNA-PKcs disassociates the DNA-PKcs.Ku complex. Thus, Ku and c-Abl provide opposing functions with regard to DNA-PK activity.
authors.affiliation: Division of Tumor Immunology,Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA.
authors.forename: S
authors.initials: S
authors.lastname: Jin
authors.forename: S
authors.initials: S
authors.lastname: Kharbanda
authors.forename: B
authors.initials: B
authors.lastname: Mayer
authors.forename: D
authors.initials: D
authors.lastname: Kufe
authors.forename: D T
authors.initials: DT
authors.lastname: Weaver
mesh_terms: D000818:Animals; D034961:Antigens, Nuclear; D001402:B-Lymphocytes; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D004265:DNA Helicases; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins / Q000378:metabolism*; D019281:Dimerization; D015723:Gene Library; D005982:Glutathione Transferase; D006801:Humans; D000072200:Ku Autoantigen; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D014176:Protein Biosynthesis; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D016315:Proto-Oncogene Proteins c-abl / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D018909:src Homology Domains
chemical_list: D034961:Antigens, Nuclear; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D016315:Proto-Oncogene Proteins c-abl; 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; C000606510:Xrcc6 protein, mouse; D000072200:Ku Autoantigen