Rif1 and Rif2 Inhibit Localization of Tel1 to DNA Ends

Yukinori Hirano, Kenzo Fukunaga, Katsunori Sugimoto

Research output: Contribution to journalArticlepeer-review

101 Scopus citations


Chromosome ends, known as telomeres, have to be distinguished from DNA double-strand breaks (DSBs) that activate the DNA-damage checkpoint. In budding yeast, the ATM homolog Tel1 associates preferentially with short telomeres and promotes telomere addition. Here, we show that the telomeric proteins Rif1 and Rif2 attenuate Tel1 recruitment to DNA ends through distinct mechanisms. Both Rif1 and Rif2 inhibit the localization of Tel1, but not the Mre11-Rad50-Xrs2 (MRX) complex, to adjacent DNA ends. Rif1 function is weaker at short telomeric repeats compared with Rif2 function and is partly dependent on Rif2. Rif2 competes with Tel1 for binding to the C terminus of Xrs2. Once Tel1 is delocalized, MRX does not associate efficiently with Rap1-covered DNA ends. These results reveal a mechanism by which telomeric DNA sequences mask DNA ends from Tel1 recognition for the regulation of telomere length.

Original languageEnglish (US)
Pages (from-to)312-322
Number of pages11
JournalMolecular cell
Issue number3
StatePublished - Feb 13 2009

All Science Journal Classification (ASJC) codes

  • Molecular Biology
  • Cell Biology


  • DNA


Dive into the research topics of 'Rif1 and Rif2 Inhibit Localization of Tel1 to DNA Ends'. Together they form a unique fingerprint.

Cite this