Nucleic Acids Research, 2001, Vol. 29, No. 11 2382-2394
© 2001 Oxford University Press
Yeast telomerase appears to frequently copy the entire template in vivo
The Lerner Research Institute, Cleveland Clinic Foundation, Department of Molecular Biology, NC20, 9500 Euclid Avenue, Cleveland, OH 44195, USA
Telomeres derived from the same formation event in wild type strains of Saccharomyces cerevisiae possess the same, precise TG1–3 sequence for the most internal 
100 bp of the 250–350 bp TG1–3 repeats. The conservation of this internal domain is thought to reflect the fact that telomere lengthening and shortening, and thus alteration of the precise TG1–3 sequence, is confined to the terminal region of the telomere. The internal domains of telomeres from yku70
and tel1 mutants, whose entire telomeres are only 100 bp, were examined by analyzing 5.1 kb of cloned TG1–3 sequences from telomeres formed during transformation of wild type, yku70 and tel1 cells. The internal domains were 97–137 bp in wild type cells, 27–36 bp in yku70 cells and 7–9 bp in tel1 cells. These data suggest that the majority of the tel1 cell TG1–3 repeats may be resynthesized during shortening and lengthening reactions while a portion of the yku70 cell telomeres are protected. TG1–3 sequences are synthesized by telomerase repeatedly copying an internal RNA template, which introduces a sequence bias into TG1–3 repeats. Analysis of in vivo-derived telomeres revealed that of the many possible high affinity binding sites for the telomere protein Rap1p in TG1–3 repeats, only those consistent with telomere hybridization to the ACACAC in the 3'-region of the telomerase RNA template followed by copying of most of the template were present. Copies of the telomerase RNA template made up 40–60% of the TG1–3 sequences from each strain and could be found in long, tandem repeats. The data suggest that in vivo yeast telomerase frequently allows telomeres to hybridize to the 3'-region of RNA template and copy most of it prior to dissociation, or that in vivo telomere processing events result in the production of TG1–3 sequences that mimic this process.
* To whom correspondence should be addressed. Tel: +1 216 445 9772; Fax: +1 216 444 0512; Email: raya{at}ccf.org
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  H. Ji, C. J. Adkins, B. R. Cartwright, and K. L. Friedman Yeast Est2p Affects Telomere Length by Influencing Association of Rap1p with Telomeric Chromatin Mol. Cell. Biol., April 1, 2008; 28(7): 2380 - 2390. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. D. Putnam, V. Pennaneach, and R. D. Kolodner Chromosome healing through terminal deletions generated by de novo telomere additions in Saccharomyces cerevisiae PNAS, September 7, 2004; 101(36): 13262 - 13267. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Forstemann and J. Lingner Molecular Basis for Telomere Repeat Divergence in Budding Yeast Mol. Cell. Biol., November 1, 2001; 21(21): 7277 - 7286. [Abstract] [Full Text] [PDF]
|
|