DNA-PK Antibody detects endogenous levels of DNA-PK protein.
Source / Purification
Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to amino acids near the carboxy-terminus of human DNA-PKcs. Antibodies are purified by protein A and peptide affinity chromatography.
Background
DNA-dependent protein kinase (DNA-PK) is an important factor in the repair of double stranded breaks in DNA. Cells lacking DNA-PK or in which DNA-PK is inhibited fail to show proper non-homologous end-joining (NHEJ) (1-7). DNA-PK is composed of two DNA-binding subunits (Ku70 and Ku86) and one 450kDa catalytic subunit (DNA-PKcs) (8). It is thought that a heterodimer of Ku70 and Ku86 binds to double-stranded DNA broken ends before DNA-PKcs binds and is activated (1, 9). Activated DNA-PKcs is a serine/threonine kinase that has been shown to phosphorylate a number of proteins in vitro, including p53, transcription factors, RNA polymerase, and Ku70/Ku86 (10, 11). DNA-PKcs autophosphorylation at multiple sites, including threonine 2609, results in an inactivation of DNA-PK kinase activity and NHEJ ability (12, 13). It has been demonstrated, however, that DNA-PK preferentially phosphorylates substrates before it autophosphorylates, suggesting that DNA-PK autophosphorylation may play a role in disassembly of the DNA repair machinery (14, 15). Autophosphorylation at threonine 2609 has also been shown to be required for DNA-PK mediated double strand break repair, and phosphorylated DNA-PK co-localizes with H2A.X and 53BP1 at sites of DNA damage (16).