Targeted disruption of the catalytic subunit of the DNA-PK gene in mice confers severe combined immunodeficiency and radiosensitivity

Immunity. 1998 Sep;9(3):355-66. doi: 10.1016/s1074-7613(00)80618-4.


The DNA-dependent protein kinase is a mammalian protein complex composed of Ku70, Ku80, and DNA-PKcs subunits that has been implicated in DNA double-strand break repair and V(D)J recombination. Here, by gene targeting, we have constructed a mouse with a disruption in the kinase domain of DNA-PKcs, generating an animal model completely devoid of DNA-PK activity. Our results demonstrate that DNA-PK activity is required for coding but not for signal join formation in mice. Although our DNA-PKcs defective mice closely resemble Scid mice, they differ by having elevated numbers of CD4+CD8+ thymocytes. This suggests that the Scid mice may not represent a null phenotype and may retain some residual DNA-PKcs function.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • B-Lymphocytes / cytology
  • Catalysis
  • Cell Differentiation / genetics
  • Cells, Cultured
  • DNA-Activated Protein Kinase
  • DNA-Binding Proteins*
  • Embryo, Mammalian
  • Fibroblasts / radiation effects
  • Gene Targeting*
  • Genes, T-Cell Receptor / genetics
  • Immunoglobulins / genetics
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Protein Structure, Tertiary
  • Protein-Serine-Threonine Kinases / chemistry*
  • Protein-Serine-Threonine Kinases / genetics*
  • Protein-Serine-Threonine Kinases / physiology
  • Radiation Tolerance / genetics*
  • Recombination, Genetic / genetics
  • Severe Combined Immunodeficiency / genetics*
  • T-Lymphocytes / cytology


  • DNA-Binding Proteins
  • Immunoglobulins
  • DNA-Activated Protein Kinase
  • Protein-Serine-Threonine Kinases