Send to

Choose Destination
EMBO J. 2008 Sep 3;27(17):2328-39. doi: 10.1038/emboj.2008.158.

Distinct roles for yeast Stn1 in telomere capping and telomerase inhibition.

Author information

Department of Molecular Biology and NCCR Program 'Frontiers in Genetics', University of Geneva, Geneva, Switzerland.


The budding yeast Cdc13, Stn1 and Ten1 (CST) proteins are proposed to function as an RPA-like complex at telomeres that protects ('caps') chromosome ends and regulates their elongation by telomerase. We show that Stn1 has a critical function in both processes through the deployment of two separable domains. The N terminus of Stn1 interacts with Ten1 and carries out its essential capping function. The C terminus of Stn1 binds both Cdc13 and Pol12, and we present genetic data indicating that the Stn1-Cdc13 interaction is required to limit continuous telomerase action. Stn1 telomere association, similar to that of Cdc13, peaks during S phase. Significantly, the magnitude of Stn1 telomere binding is independent of telomere TG tract length, suggesting that the negative effect of Stn1 on telomerase action might be regulated by a modification of CST activity or structure in cis at individual telomeres. Genetic analysis suggests that the Tell kinase exerts an effect in parallel with the Stn1 C terminus to counteract its inhibition of telomerase. These data provide new insights into the coordination of telomere capping and telomerase regulation.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center