Double strand break rejoining by the Ku-dependent mechanism of non-homologous end-joining.
The DNA-dependent protein kinase functions in the repair of DNA double strand breaks (DSBs) and in V(D)J recombination. To gain insight into the function of DNA-PK in this process we have carried out a mutation analysis of Ku80 and DNA-PKcs. Mutations at multiple sites within the N-terminal two thirds of Ku80 result in loss of Ku70/80 interaction, loss of DNA end-binding activity and inability to complement Ku80 defective cell lines. In contrast, mutations in the carboxy terminal region of the protein do not impair DNA end-binding activity but decrease the ability of Ku to activate DNA-PK. To gain insight into important functional domains within DNA-PKcs, we have analysed defective mutants, including the mouse scid cell line, and the rodent mutants, irs-20 and V-3. Mutational changes in the carboxy terminal region have been identified in all cases. Our results strongly suggest that the C-terminus of DNA-PKcs is required for kinase activity.
Jeggo
P
P
MRCCMU, University of Sussex, Brighton, East Sussex, UK.
Singleton
B
B
Beamish
H
H
Priestley
A
A
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004260:DNA Repair; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins / Q000378:metabolism*; D051379:Mice; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011995:Recombination, Genetic; D012689:Sequence Homology, Nucleic Acid
D004268:DNA-Binding Proteins; D051747:DNA-Activated Protein Kinase; D017346:Protein Serine-Threonine Kinases