The Est1 Subunit of Yeast Telomerase Binds the Tlc1 Telomerase RNA
AUTOR(ES)
Zhou, Jianlong
FONTE
American Society for Microbiology
RESUMO
Est1 is a component of yeast telomerase, and est1 mutants have senescence and telomere loss phenotypes. The exact function of Est1 is not known, and it is not homologous to components of other telomerases. We previously showed that Est1 protein coimmunoprecipitates with Tlc1 (the telomerase RNA) as well as with telomerase activity. Est1 has homology to Ebs1, an uncharacterized yeast open reading frame product, including homology to a putative RNA recognition motif (RRM) of Ebs1. Deletion of EBS1 results in short telomeres. We created point mutations in a putative RRM of Est1. One mutant was unable to complement either the senescence or the telomere loss phenotype of est1 mutants. Furthermore, the mutant protein no longer coprecipitated with the Tlc1 telomerase RNA. Mutants defective in the binding of Tlc1 RNA were nevertheless capable of binding single-stranded TG-rich DNA. Our data suggest that an important role of Est1 in the telomerase complex is to bind to the Tlc1 telomerase RNA via an RRM. Since Est1 can also bind telomeric DNA, Est1 may tether telomerase to the telomere.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=110812Documentos Relacionados
- Interactions of TLC1 (Which Encodes the RNA Subunit of Telomerase), TEL1, and MEC1 in Regulating Telomere Length in the Yeast Saccharomyces cerevisiae
- Association of the Est1 protein with telomerase activity in yeast.
- The Saccharomyces telomere-binding protein Cdc13p interacts with both the catalytic subunit of DNA polymerase α and the telomerase-associated Est1 protein
- A bulged stem tethers Est1p to telomerase RNA in budding yeast
- The catalytic subunit of yeast telomerase