title: 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.
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.
authors.affiliation: Department of Molecular Genetics, Graduate Program in Plant Cellular and Molecular Biology, Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Jingyan
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Molecular Genetics, Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Anita K
authors.initials: AK
authors.lastname: Hopper
mesh_terms: D003593:Cytoplasm / Q000378:metabolism*; D005095:Exoribonucleases / Q000378:metabolism*; D016681:Genome, Fungal; D007438:Introns; D009154:Mutation; D010766:Phosphorylation; D011130:RNA Ligase (ATP) / Q000235:genetics / Q000378:metabolism; D012343:RNA, Transfer / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D012343:RNA, Transfer; D005095:Exoribonucleases; C068398:XRN1 protein, S cerevisiae; D011130:RNA Ligase (ATP)
keywords: 5′ to 3′ exonuclease; Rlg1; Xrn1; intron turnover; tRNA ligation; tRNA splicing