Report

Fission Yeast Pot1-Tpp1 Protects Telomeres and Regulates Telomere Length

See allHide authors and affiliations

Science  06 Jun 2008:
Vol. 320, Issue 5881, pp. 1341-1344
DOI: 10.1126/science.1154819

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Telomeres are specialized chromatin structures that protect chromosomal ends. Protection of telomeres 1 (Pot1) binds to the telomeric G-rich overhang, thereby protecting telomeres and regulating telomerase. Mammalian POT1 and TPP1 interact and constitute part of the six-protein shelterin complex. Here we report that Tpz1, the TPP1 homolog in fission yeast, forms a complex with Pot1. Tpz1 binds to Ccq1 and the previously undiscovered protein Poz1 (Pot1-associated in Schizosaccharomyces pombe), which protect telomeres redundantly and regulate telomerase in positive and negative manners, respectively. Thus, the Pot1-Tpz1 complex accomplishes its functions by recruiting effector molecules Ccq1 and Poz1. Moreover, Poz1 bridges Pot1-Tpz1 and Taz1-Rap1, thereby connecting the single-stranded and double-stranded telomeric DNA regions. Such molecular architectures are similar to those of mammalian shelterin, indicating that the overall DNA-protein architecture is conserved across evolution.

View Full Text