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Yamagoshi R, Yamamoto T, Hashimoto M, Sugahara R, Shiotsuki T, Miyoshi H, Terada H, Shinohara Y. Identification of amino acid residues of mammalian mitochondrial phosphate carrier important for its functional expression in yeast cells, as achieved by PCR-mediated random mutation and gap-repair cloning. Mitochondrion 2016; 32:1-9. [PMID: 27836624 DOI: 10.1016/j.mito.2016.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Revised: 09/02/2016] [Accepted: 11/07/2016] [Indexed: 11/28/2022]
Abstract
The mitochondrial phosphate carrier (PiC) of mammals, but not the yeast one, is synthesized with a presequence. The deletion of this presequence of the mammalian PiC was reported to facilitate the import of the carrier into yeast mitochondria, but the question as to whether or not mammalian PiC could be functionally expressed in yeast mitochondria was not addressed. In the present study, we first examined whether the defective growth on a glycerol plate of yeast cells lacking the yeast PiC gene could be reversed by the introduction of expression vectors of rat PiCs. The introduction of expression vectors encoding full-length rat PiC (rPiC) or rPiC lacking the presequence (ΔNrPiC) was ineffective in restoring growth on the glycerol plates. When we examined the expression levels of individual rPiCs in yeast mitochondria, ΔNrPiC was expressed at a level similar to that of yeast PiC, but that of rPiC was very low. These results indicated that ΔNrPiC expressed in yeast mitochondria is inert. Next, we sought to isolate "revertants" viable on the glycerol plate by expressing randomly mutated ΔNrPiC, and obtained two clones. These clones carried either of two mutations, F267S or F282S; and these mutations restored the transport function of ΔNrPiC in yeast mitochondria. These two Phe residues were conserved in human carrier (hPiC), and the transport function of ΔNhPiC expressed in yeast mitochondria was also markedly improved by their substitutions. Thus, substitution of F267S or F282S was concluded to be important for functional expression of mammalian PiCs in yeast mitochondria.
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Affiliation(s)
- Ryohei Yamagoshi
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan
| | - Takenori Yamamoto
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan
| | - Mitsuru Hashimoto
- Faculty of Pharmaceutical Science, Matsuyama University, Bunkyocho-4, Matsuyama 790-8578, Japan
| | - Ryohei Sugahara
- Insect Growth Regulation Research Unit, National Institute of Agrobiological Sciences, 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Takahiro Shiotsuki
- Insect Growth Regulation Research Unit, National Institute of Agrobiological Sciences, 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Hideto Miyoshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Hiroshi Terada
- Niigata University of Pharmacy and Applied Life Sciences, Niigata 956-8603, Japan
| | - Yasuo Shinohara
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan.
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Tort F, Ferrer-Cortes X, Ribes A. Differential diagnosis of lipoic acid synthesis defects. J Inherit Metab Dis 2016; 39:781-793. [PMID: 27586888 DOI: 10.1007/s10545-016-9975-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 08/02/2016] [Accepted: 08/04/2016] [Indexed: 01/16/2023]
Abstract
Lipoic acid (LA) is an essential cofactor required for the activity of five multienzymatic complexes that play a central role in the mitochondrial energy metabolism: four 2-oxoacid dehydrogenase complexes [pyruvate dehydrogenase (PDH), branched-chain ketoacid dehydrogenase (BCKDH), 2-ketoglutarate dehydrogenase (2-KGDH), and 2-oxoadipate dehydrogenase (2-OADH)] and the glycine cleavage system (GCS). LA is synthesized in a complex multistep process that requires appropriate function of the mitochondrial fatty acid synthesis (mtFASII) and the biogenesis of iron-sulphur (Fe-S) clusters. Defects in the biosynthesis of LA have been reported to be associated with multiple and severe defects of the mitochondrial energy metabolism. In recent years, disease-causing mutations in genes encoding for proteins involved in LA metabolism have been reported: NFU1, BOLA3, IBA57, LIAS, GLRX5, LIPT1, ISCA2, and LIPT2. These studies represented important progress in understanding the pathophysiology and molecular bases underlying these disorders. Here we review current knowledge regarding involvement of LA synthesis defects in human diseases with special emphasis on the diagnostic strategies for these disorders. The clinical and biochemical characteristics of patients with LA synthesis defects are discussed and a workup for the differential diagnosis proposed.
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Affiliation(s)
- Frederic Tort
- Secció d'Errors Congènits del Metabolisme -IBC, Servei de Bioquímica i Genètica Molecular, Hospital Clínic, IDIBAPS, CIBERER, Edifici Helios III, planta baixa, C/Mejía Lequerica s/n, 08028, Barcelona, Spain.
| | - Xènia Ferrer-Cortes
- Secció d'Errors Congènits del Metabolisme -IBC, Servei de Bioquímica i Genètica Molecular, Hospital Clínic, IDIBAPS, CIBERER, Edifici Helios III, planta baixa, C/Mejía Lequerica s/n, 08028, Barcelona, Spain
| | - Antonia Ribes
- Secció d'Errors Congènits del Metabolisme -IBC, Servei de Bioquímica i Genètica Molecular, Hospital Clínic, IDIBAPS, CIBERER, Edifici Helios III, planta baixa, C/Mejía Lequerica s/n, 08028, Barcelona, Spain
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Palmieri F, Monné M. Discoveries, metabolic roles and diseases of mitochondrial carriers: A review. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2362-78. [PMID: 26968366 DOI: 10.1016/j.bbamcr.2016.03.007] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/29/2016] [Accepted: 03/01/2016] [Indexed: 12/25/2022]
Abstract
Mitochondrial carriers (MCs) are a superfamily of nuclear-encoded proteins that are mostly localized in the inner mitochondrial membrane and transport numerous metabolites, nucleotides, cofactors and inorganic anions. Their unique sequence features, i.e., a tripartite structure, six transmembrane α-helices and a three-fold repeated signature motif, allow MCs to be easily recognized. This review describes how the functions of MCs from Saccharomyces cerevisiae, Homo sapiens and Arabidopsis thaliana (listed in the first table) were discovered after the genome sequence of S. cerevisiae was determined in 1996. In the genomic era, more than 50 previously unknown MCs from these organisms have been identified and characterized biochemically using a method consisting of gene expression, purification of the recombinant proteins, their reconstitution into liposomes and transport assays (EPRA). Information derived from studies with intact mitochondria, genetic and metabolic evidence, sequence similarity, phylogenetic analysis and complementation of knockout phenotypes have guided the choice of substrates that were tested in the transport assays. In addition, the diseases associated to defects of human MCs have been briefly reviewed. This article is part of a Special Issue entitled: Mitochondrial Channels edited by Pierre Sonveaux, Pierre Maechler and Jean-Claude Martinou.
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Affiliation(s)
- Ferdinando Palmieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via E. Orabona 4, 70125 Bari, Italy.
| | - Magnus Monné
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via E. Orabona 4, 70125 Bari, Italy; Department of Sciences, University of Basilicata, Via Ateneo Lucano 10, 85100 Potenza, Italy
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Pietropaolo A, Pierri CL, Palmieri F, Klingenberg M. The switching mechanism of the mitochondrial ADP/ATP carrier explored by free-energy landscapes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:772-81. [PMID: 26874054 DOI: 10.1016/j.bbabio.2016.02.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 02/01/2016] [Accepted: 02/08/2016] [Indexed: 12/16/2022]
Abstract
The ADP/ATP carrier (AAC) of mitochondria has been an early example for elucidating the transport mechanism alternating between the external (c-) and internal (m-) states (M. Klingenberg, Biochim. Biophys. Acta 1778 (2008) 1978-2021). An atomic resolution crystal structure of AAC is available only for the c-state featuring a three repeat transmembrane domain structure. Modeling of transport mechanism remained hypothetical for want of an atomic structure of the m-state. Previous molecular dynamics studies simulated the binding of ADP or ATP to the AAC remaining in the c-state. Here, a full description of the AAC switching from the c- to the m-state is reported using well-tempered metadynamics simulations. Free-energy landscapes of the entire translocation from the c- to the m-state, based on the gyration radii of the c- and m-gates and of the center of mass, were generated. The simulations revealed three free-energy basins attributed to the c-, intermediate- and m-states separated by activation barriers. These simulations were performed with the empty and with the ADP- and ATP-loaded AAC as well as with the poorly transported AMP and guanine nucleotides, showing in the free energy landscapes that ADP and ATP lowered the activation free-energy barriers more than the other substrates. Upon binding AMP and guanine nucleotides a deeper free-energy level stabilized the intermediate-state of the AAC2 hampering the transition to the m-state. The structures of the substrate binding sites in the different states are described producing a full picture of the translocation events in the AAC.
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Affiliation(s)
- Adriana Pietropaolo
- Dipartimento di Scienze della Salute, Università di Catanzaro, Viale Europa, 88100 Catanzaro, Italy.
| | - Ciro Leonardo Pierri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via E. Orabona 4, 70125 Bari, Italy
| | - Ferdinando Palmieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via E. Orabona 4, 70125 Bari, Italy
| | - Martin Klingenberg
- Institut für Physiologische Chemie, Schillerstr.44, 80336 München, Germany.
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