ATM and the Mre11 complex combine to recognize and signal DNA double-strand breaks

Oncogene. 2007 Dec 10;26(56):7749-58. doi: 10.1038/sj.onc.1210880.


The recognition and repair of DNA double-strand breaks (DSBs) is a complex process that draws upon a multitude of proteins. This is not surprising since this is a lethal lesion if left unrepaired and also contributes to genome instability and the consequential risk of cancer and other pathologies. Some of the key proteins that recognize these breaks in DNA are mutated in distinct genetic disorders that predispose to agent sensitivity, genome instability, cancer predisposition and/or neurodegeneration. These include members of the Mre11 complex (Mre11/Rad50/Nbs1) and ataxia-telangiectasia (A-T) mutated (ATM), mutated in the human genetic disorder A-T. The mre11 (MRN) complex appears to be the major sensor of the breaks and subsequently recruits ATM where it is activated to phosphorylate in turn members of that complex and a variety of other proteins involved in cell-cycle control and DNA repair. The MRN complex is also upstream of ATM and ATR (A-T-mutated and rad3-related) protein in responding to agents that block DNA replication. To date, more than 30 ATM-dependent substrates have been identified in multiple pathways that maintain genome stability and reduce the risk of disease. We focus here on the relationship between ATM and the MRN complex in recognizing and responding to DNA DSBs.

Publication types

  • Review

MeSH terms

  • Ataxia Telangiectasia
  • Ataxia Telangiectasia Mutated Proteins
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • DNA Breaks, Double-Stranded*
  • DNA Repair
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation, Neoplastic
  • Humans
  • MRE11 Homologue Protein
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism*


  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • MRE11 protein, human
  • Tumor Suppressor Proteins
  • ATM protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • Protein-Serine-Threonine Kinases
  • MRE11 Homologue Protein