TLC1 - TEMPLATE RNA COMPONENT OF SACCHAROMYCES-CEREVISIAE TELOMERASE

Telomeres, the natural ends of linear eukaryotic chromosomes, are esse ntial for chromosome stability. Because oi the nature of DNA replicati on, telomeres require a specialized mechanism to ensure their complete duplication. Telomeres are also capable of silencing the transcriptio n of genes that are located near them. In order to identify genes in t he budding yeast Saccharomyces cerevisiae that are important for telom ere function, a screen was conducted for genes that, when expressed in high amounts, would suppress telomeric silencing. This screen lead to the identification of the gene TLC1 (telomerase component 1). TLC1 en codes the template RNA of telomerase, a ribonucleoprotein required for telomere replication in a variety of organisms. The discovery of TLC1 confirms the existence of telomerase in S. cerevisiae and may facilit ate both the analysis of this enzyme and an understanding of telomere structure and function.