Article
- The EMBO Journal (2003) 22, 1688 - 1696
- doi:10.1093/emboj/cdg154
Subject Categories:
Rap1p telomere association is not required for mitotic stability of a C3TA2 telomere in yeast
Mary Kate Alexander1 and Virginia A. Zakian1
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
Correspondence to:
Virginia A. Zakian, E-mail: vzakian@molbio.princeton.edu
Received 7 November 2002; Accepted 12 February 2003; Revised 9 January 2003
Abstract
Telomeric DNA usually consists of a repetitive sequence: C1–3A/TG1–3 in yeast, and C3TA2/T2AG3 in vertebrates. In yeast, the sequence-specific DNA- binding protein Rap1p is thought to be essential for telomere function. In a tlc1h mutant, the templating region of the telomerase RNA gene is altered so that telomerase adds the vertebrate telomere sequence instead of the yeast sequence to the chromosome end. A tlc1h strain has short but stable telomeres and no growth defect. We show here that Rap1p and the Rap1p-associated Rif2p did not bind to a telomere that contains purely vertebrate repeats, while the TG1–3 single-stranded DNA binding protein Cdc13p and the normally non-telomeric protein Tbf1p did bind this telomere. A chromosome with one entirely vertebrate-sequence telomere had a wild-type loss rate, and the telomere was maintained at a short but stable length. However, this telomere was unable to silence a telomere-adjacent URA3 gene, and the strain carrying this telomere had a severe defect in meiosis. We conclude that Rap1p localization to a C3TA2 telomere is not required for its essential mitotic functions.
Keywords:
- RAP1,
- RIF2,
- telomerase,
- telomere,
- yeast



