Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Mol Cell Biol. 2004 Dec;24(24):10857-67.

Counting of Rif1p and Rif2p on Saccharomyces cerevisiae telomeres regulates telomere length.

Author information

  • 1Department of Biochemistry and Biophysics, University of California-San Francisco, San Francisco, CA 94143-2200, USA.

Abstract

Telomere length is negatively regulated by proteins of the telomeric DNA-protein complex. Rap1p in Saccharomyces cerevisiae binds the telomeric TG(1-3) repeat DNA, and the Rap1p C terminus interacts with Rif1p and Rif2p. We investigated how these three proteins negatively regulate telomere length. We show that direct tethering of each Rif protein to a telomere shortens that telomere proportionally to the number of tethered molecules, similar to previously reported counting of Rap1p. Surprisingly, Rif proteins could also regulate telomere length even when the Rap1p C terminus was absent, and tethered Rap1p counting was completely dependent on the Rif proteins. Thus, Rap1p counting is in fact Rif protein counting. In genetic settings that cause telomeres to be abnormally long, tethering even a single Rif2p molecule was sufficient for maximal effectiveness in preventing the telomere overelongation. We show that a heterologous protein oligomerization domain, the mammalian PDZ domain, when fused to Rap1p can confer telomere length control. We propose that a nucleation and spreading mechanism is involved in forming the higher-order telomere structure that regulates telomere length.

PMID:
15572688
[PubMed - indexed for MEDLINE]
PMCID:
PMC533994
Free PMC Article

Images from this publication.See all images (6)Free text

FIG. 1.
FIG. 2.
FIG. 3.
FIG. 4.
FIG. 5.
FIG. 6.
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk