Tel1p preferentially associates with short telomeres to stimulate their elongation

Mol Cell. 2007 Sep 7;27(5):851-8. doi: 10.1016/j.molcel.2007.08.007.


In many organisms, telomeric DNA consists of long tracts of short repeats. Shorter tracts are preferentially lengthened by telomerase, suggesting a conserved mechanism that recognizes and elongates short telomeres. Tel1p, an ATM family checkpoint kinase, plays an important role in telomere elongation, as cells lacking Tel1p have short telomeres and show reduced recruitment of telomerase components to telomeres. We show that Tel1p association increased as telomeres shortened in vivo in the presence or absence of telomerase and that Tel1p preferentially associated with the shortest telomeres. Tel1p association was independent of Tel1p kinase activity and enhanced by Mre11p. Tel1p overexpression simultaneously stimulated telomerase-mediated elongation and Tel1p association with all telomeres. Thus, Tel1p preferentially associates with the shortest telomeres and stimulates their elongation by telomerase.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cellular Senescence
  • Endodeoxyribonucleases / metabolism
  • Exodeoxyribonucleases / metabolism
  • Intracellular Signaling Peptides and Proteins / analysis
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Models, Genetic
  • Protein-Serine-Threonine Kinases / analysis
  • Protein-Serine-Threonine Kinases / metabolism*
  • Recombination, Genetic
  • Saccharomyces cerevisiae Proteins / analysis
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Telomere / metabolism*
  • Telomere / ultrastructure


  • Intracellular Signaling Peptides and Proteins
  • Saccharomyces cerevisiae Proteins
  • Protein-Serine-Threonine Kinases
  • TEL1 protein, S cerevisiae
  • Endodeoxyribonucleases
  • Exodeoxyribonucleases
  • MRE11 protein, S cerevisiae