ATM gene product phosphorylates I kappa B-alpha

Cancer Res. 1997 Jan 1;57(1):24-7.


The recently cloned ATM gene is mutated in patients with ataxia telangiectasia, but its biological functions remain to be experimentally determined. Structural analysis has revealed ATM sequence similarities to the catalytic domains of phosphatidyl-3 kinase and other members of this family of yeast and mammalian proteins. Rabbit polyclonal antibodies raised against polypeptide regions unique to the COOH terminus and to the NH2 terminus of the published ATM sequence confirm ATM as M(r) approximately 350,000 protein in normal cells, which is missing in AT cells. Immunoprecipitated protein(s) is capable of phosphorylating I kappa B-alpha in an in vitro kinase assay. However, we did not observe a phosphatidyl-3 kinase or a DNA-dependent protein kinase function by ATM immunoprecipitates. These data support a protein kinase activity for ATM and suggest a role in NF-kappa B activation.

Publication types

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

MeSH terms

  • Antibodies, Monoclonal
  • Ataxia Telangiectasia Mutated Proteins
  • Cell Cycle Proteins
  • DNA-Binding Proteins / metabolism*
  • Humans
  • I-kappa B Proteins*
  • Molecular Weight
  • NF-KappaB Inhibitor alpha
  • Phosphorylation
  • Protein Kinases / physiology
  • Protein Serine-Threonine Kinases*
  • Proteins / chemistry
  • Proteins / genetics
  • Proteins / immunology
  • Proteins / physiology*
  • Tumor Cells, Cultured
  • Tumor Suppressor Proteins


  • Antibodies, Monoclonal
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • I-kappa B Proteins
  • NFKBIA protein, human
  • Proteins
  • Tumor Suppressor Proteins
  • NF-KappaB Inhibitor alpha
  • Protein Kinases
  • ATM protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • Protein Serine-Threonine Kinases