We have updated our privacy policy. If you have any question, contact us at privacy@scicrunch.org. Dismiss and don't show again

Searching across hundreds of databases

Our searching services are busy right now. Your search will reload in five seconds.

Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Telomerase RNA biogenesis involves sequential binding by Sm and Lsm complexes.

Nature | Mar 25, 2012

In most eukaryotes, the progressive loss of chromosome-terminal DNA sequences is counteracted by the enzyme telomerase, a reverse transcriptase that uses part of an RNA subunit as template to synthesize telomeric repeats. Many cancer cells express high telomerase activity, and mutations in telomerase subunits are associated with degenerative syndromes including dyskeratosis congenita and aplastic anaemia. The therapeutic value of altering telomerase activity thus provides ample impetus to study the biogenesis and regulation of this enzyme in human cells and model systems. We have previously identified a precursor of the fission yeast telomerase RNA subunit (TER1) and demonstrated that the mature 3'-end is generated by the spliceosome in a single cleavage reaction akin to the first step of splicing. Directly upstream and partly overlapping with the spliceosomal cleavage site is a putative binding site for Sm proteins. Sm and like-Sm (LSm) proteins belong to an ancient family of RNA-binding proteins represented in all three domains of life. Members of this family form ring complexes on specific sets of target RNAs and have critical roles in their biogenesis, function and turnover. Here we demonstrate that the canonical Sm ring and the Lsm2-8 complex sequentially associate with fission yeast TER1. The Sm ring binds to the TER1 precursor, stimulates spliceosomal cleavage and promotes the hypermethylation of the 5'-cap by Tgs1. Sm proteins are then replaced by the Lsm2-8 complex, which promotes the association with the catalytic subunit and protects the mature 3'-end of TER1 from exonucleolytic degradation. Our findings define the sequence of events that occur during telomerase biogenesis and characterize roles for Sm and Lsm complexes as well as for the methylase Tgs1.

Pubmed ID: 22446625 RIS Download

Mesh terms: Base Sequence | Chromosomes, Fungal | DNA-Binding Proteins | Methyltransferases | Multiprotein Complexes | Protein Binding | RNA | RNA Splicing | RNA, Fungal | RNA-Binding Proteins | Schizosaccharomyces | Schizosaccharomyces pombe Proteins | Spliceosomes | Telomerase | Telomere | tRNA Methyltransferases

Research resources used in this publication

None found

Research tools detected in this publication

None found

Data used in this publication

Associated grants

  • Agency: Howard Hughes Medical Institute, Id:

BioGRID (Data, Interactions)

Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.

We have not found any resources mentioned in this publication.