Identification and Characterization of Novel Saccharomyces cerevisiae Telomere Length Maintenance Gene, TIF1

Abstract

Telomeres, the natural ends of eukaryotic chromosomes, prevent the loss of chromosomal sequences and preclude their recognition as broken DNA. Telomere length is kept under strict regulation by the action of various proteins, some with negative and others with positive effects on telomere length. Recently, data has been accumulating to support the role of translation initiation in the control of telomere length, although the pathway for this action is poorly understood. This study has identified Tif1, a budding yeast translation initiation factor and RNA helicase, as a telomere length maintenance gene and began efforts to characterize its mechanism of action. Here, it is shown that Tif1 participates in the negative control of telomere length and in telomeric silencing in a translation-mediated manner, contributing to the complex pathway of telomere length regulation by affecting protein expression of Cdc13 and Rif1.