Lien vers Pubmed [PMID] – 24039171
Lien DOI – 10.1002/wrna.1190
Wiley Interdiscip Rev RNA ; 4(6): 709-22
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.