title: Human mitochondrial tRNAs: biogenesis, function, structural aspects, and diseases.
abstract: Mitochondria are eukaryotic organelles that generate most of the energy in the cell by oxidative phosphorylation (OXPHOS). Each mitochondrion contains multiple copies of a closed circular double-stranded DNA genome (mtDNA). Human (mammalian) mtDNA encodes 13 essential subunits of the inner membrane complex responsible for OXPHOS. These mRNAs are translated by the mitochondrial protein synthesis machinery, which uses the 22 species of mitochondrial tRNAs (mt tRNAs) encoded by mtDNA. The unique structural features of mt tRNAs distinguish them from cytoplasmic tRNAs bearing the canonical cloverleaf structure. The genes encoding mt tRNAs are highly susceptible to point mutations, which are a primary cause of mitochondrial dysfunction and are associated with a wide range of pathologies. A large number of nuclear factors involved in the biogenesis and function of mt tRNAs have been identified and characterized, including processing endonucleases, tRNA-modifying enzymes, and aminoacyl-tRNA synthetases. These nuclear factors are also targets of pathogenic mutations linked to various diseases, indicating the functional importance of mt tRNAs for mitochondrial activity.
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan. ts@chembio.t.u-tokyo.ac.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Suzuki
authors.forename: Asuteka
authors.initials: A
authors.lastname: Nagao
authors.forename: Takeo
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics / Q000378:metabolism*; D049148:Aminoacylation; D000818:Animals; D006801:Humans; D017241:MELAS Syndrome / Q000235:genetics; D008322:Mammals; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D028361:Mitochondrial Diseases / Q000235:genetics; D009154:Mutation; D010085:Oxidative Phosphorylation; D011487:Protein Conformation; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D000077278:RNA, Mitochondrial; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism*; D013891:Thiouridine / Q000031:analogs & derivatives / Q000378:metabolism; D014158:Transcription, Genetic; D014529:Uridine / Q000031:analogs & derivatives / Q000096:biosynthesis
chemical_list: C105273:2-thiouridine; C522070:5-taurinomethyluridine; D000077278:RNA, Mitochondrial; D013891:Thiouridine; D012313:RNA; D012343:RNA, Transfer; D000604:Amino Acyl-tRNA Synthetases; D014529:Uridine