title: Mitochondrial fatty acid synthesis and maintenance of respiratory competent mitochondria in yeast.
abstract: Mitochondrial FAS (fatty acid synthesis) of type II is a widely conserved process in eukaryotic organisms, with particular importance for respiratory competence and mitochondrial morphology maintenance in Saccharomyces cerevisiae. The recent characterization of three missing enzymes completes the pathway. Etr1p (enoyl thioester reductase) was identified via purification of the protein followed by molecular cloning. To study the link between FAS and cell respiration further, we also created a yeast strain that has FabI enoyl-ACP (acyl-carrier protein) reductase gene from Escherichia coli engineered to carry a mitochondrial targeting sequence in the genome, replacing the endogenous ETR1 gene. This strain is respiratory competent, but unlike the ETR1 wild-type strain, it is sensitive to triclosan on media containing only non-fermentable carbon source. A colony-colour-sectoring screen was applied for cloning of YHR067w/RMD12, the gene encoding mitochondrial 3-hydroxyacyl-ACP dehydratase (Htd2/Yhr067p), the last missing component of the mitochondrial FAS. Finally, Hfa1p was shown to be the mitochondrial acetyl-CoA carboxylase.
authors.affiliation: Biocenter Oulu and Department of Biochemistry, P.O.B. 3000, University of Oulu, FIN-90014 Oulu, Finland. kalervo.hiltunen@oulu.fi
authors.forename: J K
authors.initials: JK
authors.lastname: Hiltunen
authors.forename: F
authors.initials: F
authors.lastname: Okubo
authors.forename: V A S
authors.initials: VA
authors.lastname: Kursu
authors.forename: K J
authors.initials: KJ
authors.lastname: Autio
authors.forename: A J
authors.initials: AJ
authors.lastname: Kastaniotis
mesh_terms: D000103:Acetyl-CoA Carboxylase / Q000378:metabolism; D050745:Enoyl-(Acyl-Carrier Protein) Reductase (NADPH, B-Specific); D005227:Fatty Acids / Q000096:biosynthesis*; D008928:Mitochondria / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D044925:Oxidoreductases Acting on CH-CH Group Donors; D010101:Oxygen Consumption; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D029701:Saccharomyces cerevisiae Proteins; D044925:Oxidoreductases Acting on CH-CH Group Donors; D050745:Enoyl-(Acyl-Carrier Protein) Reductase (NADPH, B-Specific); C541904:Etr1 protein, S cerevisiae; C434934:trans-2-enoyl-CoA reductase (NADPH); D009247:NADH, NADPH Oxidoreductases; D000103:Acetyl-CoA Carboxylase