title: Discovery and Characterization of the 3-Hydroxyacyl-ACP Dehydratase Component of the Plant Mitochondrial Fatty Acid Synthase System.
abstract: We report the characterization of the Arabidopsis (Arabidopsis thaliana) 3-hydroxyacyl-acyl carrier protein dehydratase (mtHD) component of the mitochondrial fatty acid synthase (mtFAS) system, encoded by AT5G60335. The mitochondrial localization and catalytic capability of mtHD were demonstrated with a green fluorescent protein transgenesis experiment and by in vivo complementation and in vitro enzymatic assays. RNA interference (RNAi) knockdown lines with reducedmtHDexpression exhibit traits typically associated with mtFAS mutants, namely a miniaturized morphological appearance, reduced lipoylation of lipoylated proteins, and altered metabolomes consistent with the reduced catalytic activity of lipoylated enzymes. These alterations are reversed whenmthd-rnaimutant plants are grown in a 1% CO2atmosphere, indicating the link between mtFAS and photorespiratory deficiency due to the reduced lipoylation of glycine decarboxylase. In vivo biochemical feeding experiments illustrate that sucrose and glycolate are the metabolic modulators that mediate the alterations in morphology and lipid accumulation. In addition, bothmthd-rnaiandmtkasmutants exhibit reduced accumulation of 3-hydroxytetradecanoic acid (i.e. a hallmark of lipid A-like molecules) and abnormal chloroplastic starch granules; these changes are not reversible by the 1% CO2atmosphere, demonstrating two novel mtFAS functions that are independent of photorespiration. Finally, RNA sequencing analysis revealed thatmthd-rnaiandmtkasmutants are nearly equivalent to each other in altering the transcriptome, and these analyses further identified genes whose expression is affected by a functional mtFAS system but independent of photorespiratory deficiency. These data demonstrate the nonredundant nature of the mtFAS system, which contributes unique lipid components needed to support plant cell structure and metabolism.
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011.|Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and.|Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.).
authors.forename: Xin
authors.identifier: 0000-0002-7983-2103
authors.initials: X
authors.lastname: Guan
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011.|Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and.|Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.).
authors.forename: Yozo
authors.initials: Y
authors.lastname: Okazaki
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011.|Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and.|Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.).
authors.forename: Andrew
authors.initials: A
authors.lastname: Lithio
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011.|Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and.|Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.).
authors.forename: Ling
authors.identifier: 0000-0003-2371-6215
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011.|Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and.|Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.).
authors.forename: Xuefeng
authors.identifier: 0000-0003-1315-831X
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011.|Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and.|Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.).
authors.forename: Huanan
authors.initials: H
authors.lastname: Jin
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011.|Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and.|Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.).
authors.forename: Dan
authors.identifier: 0000-0002-6045-1036
authors.initials: D
authors.lastname: Nettleton
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011.|Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and.|Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.).
authors.forename: Kazuki
authors.identifier: 0000-0001-6310-5342
authors.initials: K
authors.lastname: Saito
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011; dimmas@iastate.edu.|Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and dimmas@iastate.edu.|Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.) dimmas@iastate.edu.
authors.forename: Basil J
authors.identifier: 0000-0002-4672-7139
authors.initials: BJ
authors.lastname: Nikolau
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002245:Carbon Dioxide / Q000378:metabolism; D054889:Fatty Acid Synthase, Type II / Q000235:genetics / Q000378:metabolism*; D064429:Fatty Acid Synthases / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006016:Glycolates / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism*; D055432:Metabolomics / Q000379:methods; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000201:enzymology* / Q000648:ultrastructure; D009154:Mutation; D009227:Myristic Acids / Q000378:metabolism; D030821:Plants, Genetically Modified; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017423:Sequence Analysis, RNA / Q000379:methods; D017386:Sequence Homology, Amino Acid; D013395:Sucrose / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D006016:Glycolates; D009227:Myristic Acids; C031149:glycolic acid; D002245:Carbon Dioxide; D049452:Green Fluorescent Proteins; C009893:beta-hydroxymyristic acid; D013395:Sucrose; D064429:Fatty Acid Synthases; D006836:Hydro-Lyases; C047118:3-hydroxyacyl-(acyl-carrier-protein) dehydratase; D054889:Fatty Acid Synthase, Type II