Dataset Information

DNA-end capping by the budding yeast transcription factor and subtelomeric binding protein Tbf1.

ABSTRACT: Telomere repeats in budding yeast are maintained at a constant average length and protected ('capped'), in part, by mechanisms involving the TG(1-3) repeat-binding protein Rap1. However, metazoan telomere repeats (T(2)AG(3)) can be maintained in yeast through a Rap1-independent mechanism. Here, we examine the dynamics of capping and telomere formation at an induced DNA double-strand break flanked by varying lengths of T(2)AG(3) repeats. We show that a 60-bp T(2)AG(3) repeat array induces a transient G2/M checkpoint arrest, but is rapidly elongated by telomerase to generate a stable T(2)AG(3)/TG(1-3) hybrid telomere. In contrast, a 230-bp T(2)AG(3) array induces neither G2/M arrest nor telomerase elongation. This capped state requires the T(2)AG(3)-binding protein Tbf1, but is independent of two Tbf1-interacting factors, Vid22 and Ygr071c. Arrays of binding sites for three other subtelomeric or Myb/SANT domain-containing proteins fail to display a similar end-protection effect, indicating that Tbf1 capping is an evolved function. Unexpectedly, we observed strong telomerase association with non-telomeric ends, whose elongation is blocked by a Mec1-dependent mechanism, apparently acting at the level of Cdc13 binding.

SUBMITTER: Ribaud V

PROVIDER: S-EPMC3252568 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

DNA-end capping by the budding yeast transcription factor and subtelomeric binding protein Tbf1.

Ribaud Virginie V Ribeyre Cyril C Damay Pascal P Shore David D

The EMBO journal 20110927 1

Telomere repeats in budding yeast are maintained at a constant average length and protected ('capped'), in part, by mechanisms involving the TG(1-3) repeat-binding protein Rap1. However, metazoan telomere repeats (T(2)AG(3)) can be maintained in yeast through a Rap1-independent mechanism. Here, we examine the dynamics of capping and telomere formation at an induced DNA double-strand break flanked by varying lengths of T(2)AG(3) repeats. We show that a 60-bp T(2)AG(3) repeat array induces a trans ...[more]

PMID: 21952045

Similar Datasets

Project description:Bicistronic transcripts (operon-like transcripts) have occasionally been reported in eukaryotes, including unicellular yeasts, plants, and humans, despite the fact that they lack trans-splice mechanisms. However, the characteristics of eukaryotic bicistronic transcripts are poorly understood, except for those in nematodes. Here, we describe the genomic, transcriptomic, and ribosome profiling features of bicistronic transcripts in unicellular yeasts. By comparing the expression level of bicistronic transcripts with their monocistronic equivalents, we identify two main categories of bicistronic transcripts: highly and lowly expressed. These two categories exhibit quite different features. First, highly expressed bicistronic transcripts have higher conservation within and between strains and shorter intergenic spacers with higher GC content and less stable secondary structure. Second, genes in highly expressed bicistronic transcripts have lower translation efficiency, with the second gene showing statistically significant lower translation efficiency than the first. Finally, the genes found in these highly expressed bicistronic transcripts tend to be younger, with more recent origins. Together, these results suggest that bicistronic transcripts in yeast are heterogeneous. We further propose that at least some highly expressed bicistronic transcripts appear to play a role in modulating monocistronic translation.IMPORTANCE Operons, where a single mRNA transcript encodes multiple adjacent proteins, are a widespread feature of bacteria and archaea. In contrast, the genes of eukaryotes are generally considered monocistronic. However, a number of studies have revealed the presence of bicistronic transcripts in eukaryotes, including humans. The basic features of these transcripts are largely unknown in eukaryotes, especially in organisms lacking trans-splice mechanisms. Our analyses characterize bicistronic transcripts in one such eukaryotic group, yeasts. We show that highly expressed bicistronic transcripts have unusual features compared to lowly expressed bicistronic transcripts, with several features influencing translational modulation.

Dataset Information

DNA-end capping by the budding yeast transcription factor and subtelomeric binding protein Tbf1.

Publications

DNA-end capping by the budding yeast transcription factor and subtelomeric binding protein Tbf1.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets