The p53 tumor suppressor protein is activated and phosphorylated on serine-15 in response to various DNA damaging agents. The gene product mutated in ataxia telangiectasia, ATM, acts upstream of p53 in a signal transduction pathway initiated by ionizing radiation. Immunoprecipitated ATM had intrinsic protein kinase activity and phosphorylated p53 on serine-15 in a manganese-dependent manner. Ionizing radiation, but not ultraviolet radiation, rapidly enhanced this p53-directed kinase activity of endogenous ATM. These observations, along with the fact that phosphorylation of p53 on serine-15 in response to ionizing radiation is reduced in ataxia telangiectasia cells, suggest that ATM is a protein kinase that phosphorylates p53 in vivo.
Pubmed ID: 9733515 RIS Download
Mesh terms: Ataxia Telangiectasia Mutated Proteins | Cell Cycle Proteins | Cell Line | DNA Damage | DNA-Activated Protein Kinase | DNA-Binding Proteins | Enzyme Activation | Humans | Lymphocytes | Mutation | Nuclear Proteins | Phosphatidylinositol 3-Kinases | Phosphorylation | Phosphoserine | Protein Kinases | Protein-Serine-Threonine Kinases | Proteins | Radiation, Ionizing | Recombinant Fusion Proteins | Recombinant Proteins | Signal Transduction | Transfection | Tumor Suppressor Protein p53 | Tumor Suppressor Proteins | Ultraviolet Rays
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.