title: Intron excision from precursor tRNA molecules in mammalian cells requires ATP hydrolysis and phosphorylation of tRNA-splicing endonuclease components.
abstract: The process of tRNA splicing entails removal of an intron by TSEN (tRNA-splicing endonuclease) and ligation of the resulting exon halves to generate functional tRNAs. In mammalian cells, the RNA kinase CLP1 (cleavage and polyadenylation factor I subunit) associates with TSEN and phosphorylates the 3' exon at the 5' end in vitro, suggesting a role for CLP1 in tRNA splicing. Interestingly, recent data suggest that the ATP-binding and/or hydrolysis capacity of CLP1 is required to enhance pre-tRNA cleavage. In vivo, the lack of CLP1 kinase activity leads to progressive motor neuron loss and accumulation of novel 5' leader-5' exon tRNA fragments. We have extended the investigation of the biochemical requirements in pre-tRNA splicing and found that β-γ-hydrolysable ATP is crucial for the productive generation of exon halves. In addition, we provide evidence that phosphorylation of the TSEN complex components supports efficient pre-tRNA cleavage. Taken together, our data improve the mechanistic understanding of mammalian pre-tRNA processing and its regulation.
authors.affiliation: IMBA-Institute of Molecular Biotechnology of the Austrian Academy of Sciences, A-1030 Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Mair
authors.forename: Johannes
authors.initials: J
authors.lastname: Popow
authors.forename: Karl
authors.initials: K
authors.lastname: Mechtler
authors.forename: Stefan
authors.initials: S
authors.lastname: Weitzer
authors.forename: Javier
authors.initials: J
authors.lastname: Martinez
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D004722:Endoribonucleases / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D007438:Introns; D051379:Mice; D010766:Phosphorylation; D012322:RNA Precursors / Q000235:genetics*; D012326:RNA Splicing; D012343:RNA, Transfer / Q000235:genetics*
chemical_list: D012322:RNA Precursors; D000255:Adenosine Triphosphate; D012343:RNA, Transfer; D004722:Endoribonucleases; C051012:splicing endonuclease