Ataxia-telangiectasia-mutated dependent phosphorylation of Artemis in response to DNA damage

Cancer Sci. 2005 Feb;96(2):134-41. doi: 10.1111/j.1349-7006.2005.00019.x.

Abstract

Artemis plays a crucial role in the hairpin-opening step of antigen receptor VDJ gene recombination in the presence of catalytic subunit of deoxyribonucleic acid (DNA)-dependent protein kinase (DNA-PKcs). A defect in Artemis causes human radiosensitive-severe combined immunodeficiency. Cells from Artemis-deficient patients and mice display increased chromosomal instability, but the precise function of this factor in the response to DNA damage remains to be elucidate. In this study, we show that Artemis is hyperphosphorylated in an Ataxia-telangiectasia-mutated (ATM)- and Nijmegen breakage syndrome 1 (Nbs1)-dependent manner in response to ionizing radiation (IR), and that S645 is an SQ/TQ site that contributes to retarded mobility of Artemis upon IR. The hyperphosphorylation of Artemis is markedly reduced in ATM- and Nbs1-null cells. Reintroduction of wild-type ATM or Nbs1 reconstituted Artemis hyperphosphorylation in ATM- or Nbs1-deficient cells, respectively. In support of this functional link, hyperphosphorylated Artemis was found to physically associate with the Mre11/Rad50/Nbs1 complex in an ATM-dependent manner in response to IR-induced DNA double strand breaks (DSB). Since deficiency of either DNA-Pkcs or ATM leads to defective repair of IR-induced DSB, our finding places Artemis at the signaling crossroads downstream of DNA-PKcs and ATM in IR-induced DSB repair.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ataxia Telangiectasia / genetics*
  • Ataxia Telangiectasia Mutated Proteins
  • Cell Cycle Proteins / metabolism
  • Cell Line
  • DNA Damage*
  • DNA-Activated Protein Kinase
  • DNA-Binding Proteins / metabolism
  • Endonucleases
  • Humans
  • Nuclear Proteins / metabolism
  • Nuclear Proteins / physiology*
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism
  • Transfection
  • Tumor Suppressor Proteins / metabolism

Substances

  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • NBN protein, human
  • Nuclear Proteins
  • Tumor Suppressor Proteins
  • ATM protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • Atm protein, mouse
  • DNA-Activated Protein Kinase
  • PRKDC protein, human
  • Protein-Serine-Threonine Kinases
  • DCLRE1C protein, human
  • Endonucleases