DNA damage-induced association of ATM with its target proteins requires a protein interaction domain in the N terminus of ATM

J Biol Chem. 2005 Apr 15;280(15):15158-64. doi: 10.1074/jbc.M412065200. Epub 2005 Feb 15.

Abstract

The ATM protein kinase regulates the response of the cell to DNA damage by associating with and then phosphorylating proteins involved in cell cycle checkpoints and DNA repair. Here, we report on deletion studies designed to identify protein domains required for ATM to phosphorylate target proteins and to control cell survival following exposure to ionizing radiation. Deletion studies demonstrated that amino acids 1-150 of ATM were required for the ATM protein to regulate cellular radiosensitivity. Additional deletions and point mutations indicated that this domain extended from amino acids 81-106 of ATM, with amino acid substitutions located between amino acids 91 and 97 inactivating the functional activity of ATM. When ATM with mutations in this region (termed ATM90) was expressed in AT cells, it was unable to restore normal radiosensitivity to the cells. However, ATM90 retained normal kinase activity and was autophosphorylated on serine 1981 following exposure to DNA damage. Furthermore, wild-type ATM displayed DNA-damage induced association with p53, brca1, and LKB1 in vivo, whereas ATM90 failed to form productive complexes with these target proteins either in vivo or in vitro. Furthermore, ATM90 did not phosphorylate p53 in vivo and did not form nuclear foci in response to ionizing radiation. We propose that amino acids 91-97 of ATM contain a protein interaction domain required for the DNA damage-induced association between ATM and its target proteins, including the brca1, p53, and LKB1 proteins. Furthermore, this domain of ATM is required for ATM to form nuclear foci following exposure to ionizing radiation.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Ataxia Telangiectasia Mutated Proteins
  • BRCA1 Protein / metabolism
  • Blotting, Western
  • Cell Cycle
  • Cell Cycle Proteins / metabolism
  • Cell Cycle Proteins / physiology*
  • Cell Line
  • Cell Nucleus / metabolism
  • Cell Survival
  • DNA Damage*
  • DNA Repair
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / physiology*
  • Dose-Response Relationship, Radiation
  • Gene Deletion
  • Genetic Vectors
  • Glutathione / chemistry
  • Glutathione Transferase / metabolism
  • Humans
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Mutation
  • Phosphorylation
  • Plasmids / metabolism
  • Point Mutation
  • Protein Binding
  • Protein Biosynthesis
  • Protein Structure, Tertiary
  • Protein-Serine-Threonine Kinases / metabolism
  • Protein-Serine-Threonine Kinases / physiology*
  • Radiation, Ionizing
  • Sequence Homology, Amino Acid
  • Tumor Suppressor Protein p53 / metabolism
  • Tumor Suppressor Proteins / metabolism
  • Tumor Suppressor Proteins / physiology*

Substances

  • BRCA1 Protein
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Tumor Suppressor Protein p53
  • Tumor Suppressor Proteins
  • Glutathione Transferase
  • STK11 protein, human
  • ATM protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • Protein-Serine-Threonine Kinases
  • Glutathione