title: Ribosome profiling reveals features of normal and disease-associated mitochondrial translation.
abstract: Mitochondria are essential cellular organelles for generation of energy and their dysfunction may cause diabetes, Parkinson's disease and multi-systemic failure marked by failure to thrive, gastrointestinal problems, lactic acidosis and early lethality. Disease-associated mitochondrial mutations often affect components of the mitochondrial translation machinery. Here we perform ribosome profiling to measure mitochondrial translation at nucleotide resolution. Using a protocol optimized for the retrieval of mitochondrial ribosome protected fragments (RPFs) we show that the size distribution of wild-type mitochondrial RPFs follows a bimodal distribution peaking at 27 and 33 nucleotides, which is distinct from the 30-nucleotide peak of nuclear RPFs. Their cross-correlation suggests generation of mitochondrial RPFs during ribosome progression. In contrast, RPFs from patient-derived mitochondria mutated in tRNA-Tryptophan are centered on tryptophan codons and reduced downstream, indicating ribosome stalling. Intriguingly, long RPFs are enriched in mutated mitochondria, suggesting they characterize stalled ribosomes. Our findings provide the first model for translation in wild-type and disease-triggering mitochondria.
authors.affiliation: 1] Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands [2].
authors.forename: Koos
authors.initials: K
authors.lastname: Rooijers
authors.forename: Fabricio
authors.initials: F
authors.lastname: Loayza-Puch
authors.forename: Leo G
authors.initials: LG
authors.lastname: Nijtmans
authors.forename: Reuven
authors.initials: R
authors.lastname: Agami
mesh_terms: D002460:Cell Line; D004194:Disease / Q000235:genetics*; D006801:Humans; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis; D012364:RNA, Transfer, Trp / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000235:genetics* / Q000378:metabolism; D059467:Transcriptome
chemical_list: D024101:Mitochondrial Proteins; D012364:RNA, Transfer, Trp