title: An interplay between transcription, processing, and degradation determines tRNA levels in yeast.
abstract: tRNA biogenesis in yeast involves the synthesis of the initial transcript by RNA polymerase III followed by processing and controlled degradation in both the nucleus and the cytoplasm. A vast landscape of regulatory elements controlling tRNA stability in yeast has emerged from recent studies. Diverse pathways of tRNA maturation generate multiple stable and unstable intermediates. A significant impact on tRNA stability is exerted by a variety of nucleotide modifications. Pre-tRNAs are targets of exosome-dependent surveillance in the nucleus. Some tRNAs that are hypomodified or bear specific destabilizing mutations are directed to the rapid tRNA decay pathway leading to 5'→3' exonucleolytic degradation by Rat1 and Xrn1. tRNA molecules are selectively marked for degradation by a double CCA at their 3' ends. In addition, under different stress conditions, tRNA half-molecules can be generated by independent endonucleolytic cleavage events. Recent studies reveal unexpected relationships between the subsequent steps of tRNA biosynthesis and the mechanisms controlling its quality and turnover.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Dominika
authors.initials: D
authors.lastname: Wichtowska
authors.forename: Tomasz W
authors.initials: TW
authors.lastname: Turowski
authors.forename: Magdalena
authors.initials: M
authors.lastname: Boguta
mesh_terms: D002467:Cell Nucleus / Q000235:genetics; D003593:Cytoplasm / Q000235:genetics; D063326:Exosome Multienzyme Ribonuclease Complex / Q000235:genetics; D012320:RNA Polymerase III / Q000235:genetics; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics*; D020871:RNA Stability / Q000235:genetics*; D012343:RNA, Transfer / Q000096:biosynthesis* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D012343:RNA, Transfer; D012320:RNA Polymerase III; D063326:Exosome Multienzyme Ribonuclease Complex