Hairpin opening and overhang processing by an Artemis/DNA-dependent protein kinase complex in nonhomologous end joining and V(D)J recombination

Cell. 2002 Mar 22;108(6):781-94. doi: 10.1016/s0092-8674(02)00671-2.

Abstract

Mutations in the Artemis protein in humans result in hypersensitivity to DNA double-strand break-inducing agents and absence of B and T lymphocytes (radiosensitive severe combined immune deficiency [RS-SCID]). Here, we report that Artemis forms a complex with the 469 kDa DNA-dependent protein kinase (DNA-PKcs) in the absence of DNA. The purified Artemis protein alone possesses single-strand-specific 5' to 3' exonuclease activity. Upon complex formation, DNA-PKcs phosphorylates Artemis, and Artemis acquires endonucleolytic activity on 5' and 3' overhangs, as well as hairpins. Finally, the Artemis:DNA-PKcs complex can open hairpins generated by the RAG complex. Thus, DNA-PKcs regulates Artemis by both phosphorylation and complex formation to permit enzymatic activities that are critical for the hairpin-opening step of V(D)J recombination and for the 5' and 3' overhang processing in nonhomologous DNA end joining.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • DNA, Single-Stranded / chemistry
  • DNA, Single-Stranded / metabolism
  • DNA-Activated Protein Kinase
  • DNA-Binding Proteins / metabolism
  • Endonucleases / genetics
  • Endonucleases / metabolism
  • Enzyme Activation
  • HMGB1 Protein / metabolism
  • Homeodomain Proteins / metabolism
  • Humans
  • Nuclear Proteins*
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Recombination, Genetic / physiology*
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism*

Substances

  • DNA, Single-Stranded
  • DNA-Binding Proteins
  • HMGB1 Protein
  • Homeodomain Proteins
  • Nuclear Proteins
  • RAG2 protein, human
  • V(D)J recombination activating protein 2
  • RAG-1 protein
  • Adenosine Triphosphate
  • DNA-Activated Protein Kinase
  • PRKDC protein, human
  • Protein-Serine-Threonine Kinases
  • DCLRE1C protein, human
  • Endonucleases
  • beta-Lactamases