The DNA-dependent protein kinase catalytic subunit is phosphorylated in vivo on threonine 3950, a highly conserved amino acid in the protein kinase domain.

ABSTRACT: The protein kinase activity of the DNA-dependent protein kinase (DNA-PK) is required for the repair of DNA double-strand breaks (DSBs) via the process of nonhomologous end joining (NHEJ). However, to date, the only target shown to be functionally relevant for the enzymatic role of DNA-PK in NHEJ is the large catalytic subunit DNA-PKcs itself. In vitro, autophosphorylation of DNA-PKcs induces kinase inactivation and dissociation of DNA-PKcs from the DNA end-binding component Ku70/Ku80. Phosphorylation within the two previously identified clusters of phosphorylation sites does not mediate inactivation of the assembled complex and only partially regulates kinase disassembly, suggesting that additional autophosphorylation sites may be important for DNA-PK function. Here, we show that DNA-PKcs

SUBMITTER: Douglas P 

PROVIDER: S-EPMC1820444 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature