title: ATP synthesis-coupled and -uncoupled acetate production from acetyl-CoA by mitochondrial acetate:succinate CoA-transferase and acetyl-CoA thioesterase in Trypanosoma.
abstract: Insect stage trypanosomes use an "acetate shuttle" to transfer mitochondrial acetyl-CoA to the cytosol for the essential fatty acid biosynthesis. The mitochondrial acetate sources are acetate:succinate CoA-transferase (ASCT) and an unknown enzymatic activity. We have identified a gene encoding acetyl-CoA thioesterase (ACH) activity, which is shown to be the second acetate source. First, RNAi-mediated repression of ASCT in the ACH null background abolishes acetate production from glucose, as opposed to both single ASCT and ACH mutants. Second, incorporation of radiolabeled glucose into fatty acids is also abolished in this ACH/ASCT double mutant. ASCT is involved in ATP production, whereas ACH is not, because the ASCT null mutant is ∼1000 times more sensitive to oligomycin, a specific inhibitor of the mitochondrial F(0)/F(1)-ATP synthase, than wild-type cells or the ACH null mutant. This was confirmed by RNAi repression of the F(0)/F(1)-ATP synthase F(1)β subunit, which is lethal when performed in the ASCT null background but not in the wild-type cells or the ACH null background. We concluded that acetate is produced from both ASCT and ACH; however, only ASCT is responsible, together with the F(0)/F(1)-ATP synthase, for ATP production in the mitochondrion.
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France.
authors.forename: Yoann
authors.initials: Y
authors.lastname: Millerioux
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France.
authors.forename: Pauline
authors.initials: P
authors.lastname: Morand
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Biran
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Mazet
authors.affiliation: Laboratoire de Biogenèse Membranaire, UMR 5200, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Moreau
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Wargnies
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Ebikeme
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France.
authors.forename: Kamel
authors.initials: K
authors.lastname: Deramchia
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; CNRS, UMR5504, F-31400 Toulouse, France.
authors.forename: Lara
authors.initials: L
authors.lastname: Gales
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; CNRS, UMR5504, F-31400 Toulouse, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Portais
authors.affiliation: Biozentrum, Genetik, Ludwig-Maximilians-Universität München, Grosshadernerstr, 2-4, D-82152 Martinsried, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Boshart
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Franconi
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Université Bordeaux Segalen, CNRS, 146 Rue Léo Saignat, 33076 Bordeaux, France. Electronic address: bringaud@rmsb.u-bordeaux2.fr.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bringaud
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000105:Acetyl Coenzyme A / Q000235:genetics / Q000378:metabolism*; D000104:Acetyl-CoA Hydrolase / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D015256:Coenzyme A-Transferases / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000235:genetics / Q000378:metabolism; D005947:Glucose / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000201:enzymology* / Q000235:genetics
chemical_list: D000085:Acetates; D005227:Fatty Acids; D024101:Mitochondrial Proteins; D015800:Protozoan Proteins; D000105:Acetyl Coenzyme A; D000255:Adenosine Triphosphate; D015256:Coenzyme A-Transferases; D000104:Acetyl-CoA Hydrolase; D006180:Proton-Translocating ATPases; D005947:Glucose