Healing for destruction: tRNA intron degradation in yeast is a two-step cytoplasmic process catalyzed by tRNA ligase Rlg1 and 5′-to-3′ exonuclease Xrn1
- Jingyan Wu1,2,3 and
- Anita K. Hopper1,3,4
- 1Department of Molecular Genetics,
- 2Graduate Program in Plant Cellular and Molecular Biology,
- 3Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
Abstract
In eukaryotes and archaea, tRNA splicing generates free intron molecules. Although ∼600,000 introns are produced per generation in yeast, they are barely detectable in cells, indicating efficient turnover of introns. Through a genome-wide search for genes involved in tRNA biology in yeast, we uncovered the mechanism for intron turnover. This process requires healing of the 5′ termini of linear introns by the tRNA ligase Rlg1 and destruction by the cytoplasmic tRNA quality control 5′-to-3′ exonuclease Xrn1, which has specificity for RNAs with 5′ monophosphate.
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Footnotes
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↵4 Corresponding author
E-mail hopper.64{at}osu.edu
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Supplemental material is available for this article.
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Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.244673.114.
- Received May 2, 2014.
- Accepted June 3, 2014.
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