Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
, 26 (17), 3944-8

DNA-PK Is Essential Only for Coding Joint Formation in V(D)J Recombination

Comparative Study

DNA-PK Is Essential Only for Coding Joint Formation in V(D)J Recombination

P Kulesza et al. Nucleic Acids Res.


The analysis of the role of DNA-dependent protein kinase (DNA-PK) in DNA double-strand break repair and V(D)J recombination is based primarily on studies of murine scid, in which only the C-terminal 2% of the protein is deleted and the remaining 98% is expressed at levels that are within an order of magnitude of normal. In murine scid, signal joint formation is observed at normal levels, even though coding joint formation is reduced over three orders of magnitude. In contrast, a closely associated protein, Ku, is necessary for both coding and signal joint formation. Based on these observations, a reasonable hypothesis has been that absence of the DNA-PK protein (rather than merely its C-terminal 2% truncation) would ablate signal joint formation along with coding joint formation. In fact, a study of equine SCID, in which there is a much larger truncation of the DNA-PK protein, has suggested that signal joints do fail to form. In our current study, we have analyzed signal and coding joint formation in a malignant glioma cell line, M059J, which was previously shown to be deficient in DNA-PK. Our quantitative analysis shows that full-length protein levels are reduced at least 200-fold, to a level that is undetectable, yet signal joint formation occurs at wild-type levels. This result demonstrates that at least this form of non-homologous DNA end joining can occur in the absence of DNA-PK.

Similar articles

See all similar articles

Cited by 9 PubMed Central articles

See all "Cited by" articles


    1. Nature. 1983 Feb 10;301(5900):527-30 - PubMed
    1. J Biol Chem. 1998 May 22;273(21):13058-64 - PubMed
    1. EMBO J. 1989 Mar;8(3):735-42 - PubMed
    1. Science. 1990 Jun 22;248(4962):1517-23 - PubMed
    1. Mol Cell Biol. 1990 Dec;10(12):6460-71 - PubMed

Publication types