Dual role for Saccharomyces cerevisiae Tel1 in the checkpoint response to double-strand breaks

EMBO Rep. 2007 Apr;8(4):380-7. doi: 10.1038/sj.embor.7400911. Epub 2007 Mar 9.


The main responder to DNA double-strand breaks (DSBs) in mammals is ataxia telangiectasia mutated (ATM), whereas DSB-induced checkpoint activation in budding yeast seems to depend primarily on the ATM and Rad-3-related (ATR) orthologue Mec1. Here, we show that Saccharomyces cerevisiae Tel1, the ATM orthologue, has two functions in checkpoint response to DSBs. First, Tel1 participates, together with the MRX complex, in Mec1-dependent DSB-induced checkpoint activation by increasing the efficiency of single-stranded DNA accumulation at the ends of DSBs, and this checkpoint function can be overcome by overproducing the exonuclease Exo1. Second, Tel1 can activate the checkpoint response to DSBs independently of Mec1, although its signalling activity only becomes apparent when several DSBs are generated. Furthermore, we provide evidence that the kinetics of DSB resection can influence Tel1 activation, indicating that processing of the DSB termini might influence the transition from Tel1/ATM- to Mec1/ATR-dependent checkpoint.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ataxia Telangiectasia Mutated Proteins
  • Cell Cycle Proteins / physiology
  • DNA Breaks, Double-Stranded*
  • DNA, Single-Stranded / metabolism
  • DNA-Binding Proteins / physiology
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Intracellular Signaling Peptides and Proteins / physiology*
  • Kinetics
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism
  • Protein-Serine-Threonine Kinases / physiology*
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / physiology*
  • Tumor Suppressor Proteins / physiology


  • Cell Cycle Proteins
  • DNA, Single-Stranded
  • DNA-Binding Proteins
  • Intracellular Signaling Peptides and Proteins
  • Saccharomyces cerevisiae Proteins
  • Tumor Suppressor Proteins
  • ATM protein, human
  • ATR protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • MEC1 protein, S cerevisiae
  • Protein-Serine-Threonine Kinases
  • TEL1 protein, S cerevisiae