title: Elongator-dependent modification of cytoplasmic tRNALysUUU is required for mitochondrial function under stress conditions.
abstract: To gain a wider view of the pathways that regulate mitochondrial function, we combined the effect of heat stress on respiratory capacity with the discovery potential of a genome-wide screen in Saccharomyces cerevisiae. We identified 105 new genes whose deletion impairs respiratory growth at 37°C by interfering with processes such as transcriptional regulation, ubiquitination and cytosolic tRNA wobble uridine modification via 5-methoxycarbonylmethyl-2-thiouridine formation. The latter process, specifically required for efficient decoding of AA-ending codons under stress conditions, was covered by multiple genes belonging to the Elongator (e.g. ELP3) and urmylation (e.g., NCS6) pathways. ELP3 or NCS6 deletants had impaired mitochondrial protein synthesis. Their respiratory deficiency was selectively rescued by overexpression of tRNA(Lys) UUU as well by overexpression of genes (BCK1 and HFM1) with a strong bias for the AAA codon read by this tRNA. These data extend the mitochondrial regulome, demonstrate that heat stress can impair respiration by disturbing cytoplasmic translation of proteins critically involved in mitochondrial function and document, for the first time, the involvement in such process of the Elongator and urmylation pathways. Given the conservation of these pathways, the present findings may pave the way to a better understanding of the human mitochondrial regulome in health and disease.
authors.affiliation: Department of Life Sciences, University of Parma, 43124 Parma, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Tigano
authors.affiliation: Department of Life Sciences, University of Parma, 43124 Parma, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Ruotolo
authors.affiliation: Department of Life Sciences, University of Parma, 43124 Parma, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Dallabona
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
authors.forename: Flavia
authors.initials: F
authors.lastname: Fontanesi
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, USA.
authors.forename: Antoni
authors.initials: A
authors.lastname: Barrientos
authors.affiliation: Department of Life Sciences, University of Parma, 43124 Parma, Italy claudia.donnini@unipr.it.
authors.forename: Claudia
authors.initials: C
authors.lastname: Donnini
authors.affiliation: Department of Life Sciences, University of Parma, 43124 Parma, Italy simone.ottonello@unipr.it.
authors.forename: Simone
authors.initials: S
authors.lastname: Ottonello
mesh_terms: D019069:Cell Respiration; D003062:Codon; D003580:Cytochromes / Q000737:chemistry; D003593:Cytoplasm / Q000378:metabolism; D017353:Gene Deletion; D016681:Genome, Fungal; D051548:Histone Acetyltransferases / Q000235:genetics*; D006358:Hot Temperature; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010085:Oxidative Phosphorylation; D010641:Phenotype; D012357:RNA, Transfer, Lys / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D013312:Stress, Physiological / Q000235:genetics*; D014529:Uridine / Q000378:metabolism
chemical_list: D003062:Codon; D003580:Cytochromes; D012357:RNA, Transfer, Lys; D029701:Saccharomyces cerevisiae Proteins; C526363:Elp3 protein, S cerevisiae; D051548:Histone Acetyltransferases; D014529:Uridine