Upstream / Downstream


Explore pathways related to this product.

Our U.S. Offices Are Closed

Our U.S. offices are closed in observance of Thanksgiving. We will reopen on Monday, November 30th.

Thank you for your patience.


Find answers on our FAQs page.


Visit PhosphoSitePlus®

PTM information and tools available.


450 Rabbit

Product Usage Information

Storage: Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA and 50% glycerol. Store at –20°C. Do not aliquot the antibody.

Specificity / Sensitivity

Phospho-DNA-PK (Ser2056) Antibody recognizes endogenous levels of DNA-PK protein only when phosphorylated at Ser2056.

Species predicted to react based on 100% sequence homology: Monkey

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Ser2056 of human DNA-PK protein. Antibodies are purified by protein A and peptide affinity chromatography.

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 nonhomologous end-joining (NHEJ) (1-7). DNA-PK is composed of two DNA-binding subunits (Ku70 and Ku86) and one 450 kDa 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 Thr2609 and Ser2056, 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 Thr2609 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). Phosphorylation at Ser2056 occurs in response to double-stranded DNA breaks and ATM activation (17).

1.  Gottlieb, T.M. and Jackson, S.P. (1993) Cell 72, 131-42.

2.  Hartley, K. O. et al. (1995) Cell 82, 840-856.

3.  Rosenzweig, K.E. et al. (1997) Clin Cancer Res 3, 1149-56.

4.  Jackson, S.P. and Jeggo, P.A. (1995) Trends Biochem Sci 20, 412-5.

5.  Roth, D.B. et al. (1995) Curr Biol 5, 496-9.

6.  Baumann, P. and West, S.C. (1998) Proc Natl Acad Sci U S A 95, 14066-70.

7.  Chen, S. et al. (2001) J Biol Chem 276, 24323-30.

8.  Jeggo, P.A. (1997) Mutat Res 384, 1-14.

9.  Suwa, A. et al. (1994) Proc Natl Acad Sci U S A 91, 6904-8.

10.  Anderson, C.W. and Lees-Miller, S.P. (1992) Crit Rev Eukaryot Gene Expr 2, 283-314.

11.  Kuhn, A. et al. (1995) Genes Dev 9, 193-203.

12.  Chan, D.W. and Lees-Miller, S.P. (1996) J Biol Chem 271, 8936-41.

13.  Douglas, P. et al. (2002) Biochem. J. 368, 243-251.

14.  Lees-Miller, S.P. et al. (1992) Mol Cell Biol 12, 5041-9.

15.  Jackson, S.P. et al. (1990) Cell 63, 155-65.

16.  Chan, D.W. et al. (2002) Genes Dev 16, 2333-8.

17.  Yajima, H. et al. (2009) J Mol Biol 385, 800-10.

Entrez-Gene Id 5591
Swiss-Prot Acc. P78527

For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.

Phospho-DNA-PK (Ser2056) Antibody