title: A sequence motif within trypanosome precursor tRNAs influences abundance and mitochondrial localization.
abstract: Trypanosoma brucei lacks mitochondrial genes encoding tRNAs and must import nuclearly encoded tRNAs from the cytosol. The mechanism and specificity of this process remain unclear. We have identified a unique sequence motif, YGG(C/A)RRC, upstream of the genes encoding mitochondrially localized tRNAs in T. brucei. Both in vitro import studies and in vivo transfection studies indicate that deletion of the YGG(C/A)RRC sequence alters mitochondrial localization of tRNA(Leu), and in vivo studies also show a decrease in the cellular abundance of tRNA(Leu). These studies provide direct evidence for cis-acting RNA motifs within precursor tRNAs that facilitate the selection of tRNAs for mitochondrial import in trypanosomes. Furthermore, we found that mutations to the YGG(C/A)RRC sequence also altered the intracellular distribution of other endogenous tRNAs, suggesting a general role for this sequence in tRNA trafficking in trypanosomes.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
authors.forename: R Lynn
authors.initials: RL
authors.lastname: Sherrer
authors.forename: Audra E
authors.initials: AE
authors.lastname: Yermovsky-Kammerer
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Hajduk
mesh_terms: D000818:Animals; D001483:Base Sequence; D001693:Biological Transport, Active; D017124:Conserved Sequence; D003600:Cytosol / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D012322:RNA Precursors / Q000235:genetics* / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D016053:RNA, Protozoan / Q000235:genetics* / Q000378:metabolism*; D012356:RNA, Transfer, Leu / Q000235:genetics* / Q000378:metabolism*; D017384:Sequence Deletion; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000378:metabolism*
chemical_list: D012322:RNA Precursors; D016053:RNA, Protozoan; D012356:RNA, Transfer, Leu; C091001:pre-tRNA(Leu)