Mutations in the anticodon stem of tRNA cause accumulation and Met22-dependent decay of pre-tRNA in yeast
Autor: | Alayna C. Hauke, Eric M. Phizicky, Thareendra De Zoysa, Matthew J. Payea |
---|---|
Rok vydání: | 2019 |
Předmět: |
RNA Splicing
RNA Stability Saccharomyces cerevisiae Biology medicine.disease_cause Article 03 medical and health sciences RNA Transfer Nucleotidases Anticodon RNA Precursors medicine Molecular Biology 030304 developmental biology 0303 health sciences Mutation 030302 biochemistry & molecular biology Intron Exons Adenosine Introns Yeast Cell biology Transfer RNA RNA splicing Nucleic Acid Conformation TRNA maturation medicine.drug |
Zdroj: | RNA |
ISSN: | 1469-9001 1355-8382 |
Popis: | During tRNA maturation in yeast, aberrant pre-tRNAs are targeted for 3′–5′ degradation by the nuclear surveillance pathway, and aberrant mature tRNAs are targeted for 5′–3′ degradation by the rapid tRNA decay (RTD) pathway. RTD is catalyzed by the 5′–3′ exonucleases Xrn1 and Rat1, which act on tRNAs with an exposed 5′ end due to the lack of certain body modifications or the presence of destabilizing mutations in the acceptor stem, T-stem, or tRNA fold. RTD is inhibited by mutation of MET22, likely due to accumulation of the Met22 substrate adenosine 3′,5′ bis-phosphate, which inhibits 5′-3′ exonucleases. Here we provide evidence for a new tRNA quality control pathway in which intron-containing pre-tRNAs with destabilizing mutations in the anticodon stem are targeted for Met22-dependent pre-tRNA decay (MPD). Multiple SUP4οc anticodon stem variants that are subject to MPD each perturb the bulge-helix-bulge structure formed by the anticodon stem–loop and intron, which is important for splicing, resulting in substantial accumulation of end-matured unspliced pre-tRNA as well as pre-tRNA decay. Mutations that restore exon–intron structure commensurately reduce pre-tRNA accumulation and MPD. The MPD pathway can contribute substantially to decay of anticodon stem variants, since pre-tRNA decay is largely suppressed by removal of the intron or by restoration of exon–intron structure, each also resulting in increased tRNA levels. The MPD pathway is general as it extends to variants of tRNATyr(GUA) and tRNASer(CGA). These results demonstrate that the integrity of the anticodon stem–loop and the efficiency of tRNA splicing are monitored by a quality control pathway. |
Databáze: | OpenAIRE |
Externí odkaz: |