title: The transmembrane prolines of the mitochondrial ADP/ATP carrier are involved in nucleotide binding and transport and its biogenesis.
abstract: The mitochondrial ADP/ATP carrier (Ancp) is a paradigm of the mitochondrial carrier family, which allows cross-talk between mitochondria, where cell energy is mainly produced, and cytosol, where cell energy is mainly consumed. The members of this family share numerous structural and functional characteristics. Resolution of the atomic structure of the bovine Ancp, in a complex with one of its specific inhibitors, revealed interesting features and suggested the involvement of some particular residues in the movements of the protein to perform translocation of nucleotides from one side of the membrane to the other. They correspond to three prolines located in the odd-numbered transmembrane helices (TMH), Pro-27, Pro-132, and Pro-229. The corresponding residues of the yeast Ancp (Pro-43, Ser-147, and Pro-247) were mutated into alanine or leucine, one at a time and analysis of the various mutants evidenced a crucial role of Pro-43 and Pro-247 during nucleotide transport. Beside, replacement of Ser-147 with proline does not inactivate Ancp and this is discussed in view of the conservation of the three prolines at equivalent positions in the Ancp sequences. These prolines belong to the signature sequences of the mitochondrial carriers and we propose they play a dual role in the mitochondrial ADP/ATP carrier function and biogenesis. Unexpectedly their mutations cause more general effects on mitochondrial biogenesis and morphology, as evidenced by measurements of respiratory rates, cytochrome contents, and also clearly highlighted by fluorescence microscopy.
authors.affiliation: Laboratoire de Physiologie Moléculaire et Cellulaire, Université de Bordeaux, F-33000 Bordeaux, France; CNRS, IBGC, UMR 5095, F-33000 Bordeaux, France and.
authors.forename: Marion
authors.initials: M
authors.lastname: Babot
authors.affiliation: Laboratoire de Physiologie Moléculaire et Cellulaire, Université de Bordeaux, F-33000 Bordeaux, France; CNRS, IBGC, UMR 5095, F-33000 Bordeaux, France and.
authors.forename: Corinne
authors.initials: C
authors.lastname: Blancard
authors.affiliation: Université Joseph Fourier, Equipe Dynamique des Organelles et Plasticité Cellulaire, Laboratoire de Biologie à Grande Echelle (BGE), iRTSV-CEA de Grenoble, 17 rue des Martyrs, F-38054 Grenoble cedex 9, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Pelosi
authors.affiliation: Laboratoire de Physiologie Moléculaire et Cellulaire, Université de Bordeaux, F-33000 Bordeaux, France; CNRS, IBGC, UMR 5095, F-33000 Bordeaux, France and.
authors.forename: Guy J-M
authors.initials: GJ
authors.lastname: Lauquin
authors.affiliation: Laboratoire de Physiologie Moléculaire et Cellulaire, Université de Bordeaux, F-33000 Bordeaux, France; CNRS, IBGC, UMR 5095, F-33000 Bordeaux, France and. Electronic address: v.trezeguet@cbmn.u-bordeaux.fr.
authors.forename: Véronique
authors.initials: V
authors.lastname: Trézéguet
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001692:Biological Transport; D002417:Cattle; D000226:Mitochondrial ADP, ATP Translocases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020125:Mutation, Missense; D011392:Proline / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D000226:Mitochondrial ADP, ATP Translocases; D011392:Proline