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Sanford JD, Franklin D, Grois GA, Jin A, Zhang Y. Carnitine o-octanoyltransferase is a p53 target that promotes oxidative metabolism and cell survival following nutrient starvation. J Biol Chem 2023; 299:104908. [PMID: 37307919 PMCID: PMC10339192 DOI: 10.1016/j.jbc.2023.104908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 05/11/2023] [Accepted: 06/01/2023] [Indexed: 06/14/2023] Open
Abstract
Whereas it is known that p53 broadly regulates cell metabolism, the specific activities that mediate this regulation remain partially understood. Here, we identified carnitine o-octanoyltransferase (CROT) as a p53 transactivation target that is upregulated by cellular stresses in a p53-dependent manner. CROT is a peroxisomal enzyme catalyzing very long-chain fatty acids conversion to medium chain fatty acids that can be absorbed by mitochondria during β-oxidation. p53 induces CROT transcription through binding to consensus response elements in the 5'-UTR of CROT mRNA. Overexpression of WT but not enzymatically inactive mutant CROT promotes mitochondrial oxidative respiration, while downregulation of CROT inhibits mitochondrial oxidative respiration. Nutrient depletion induces p53-dependent CROT expression that facilitates cell growth and survival; in contrast, cells deficient in CROT have blunted cell growth and reduced survival during nutrient depletion. Together, these data are consistent with a model where p53-regulated CROT expression allows cells to be more efficiently utilizing stored very long-chain fatty acids to survive nutrient depletion stresses.
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Affiliation(s)
- Jack D Sanford
- Department of Radiation Oncology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Derek Franklin
- Department of Radiation Oncology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Gabriella A Grois
- Department of Radiation Oncology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Aiwen Jin
- Department of Radiation Oncology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Yanping Zhang
- Department of Radiation Oncology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
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2
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Dambrova M, Makrecka-Kuka M, Kuka J, Vilskersts R, Nordberg D, Attwood MM, Smesny S, Sen ZD, Guo AC, Oler E, Tian S, Zheng J, Wishart DS, Liepinsh E, Schiöth HB. Acylcarnitines: Nomenclature, Biomarkers, Therapeutic Potential, Drug Targets, and Clinical Trials. Pharmacol Rev 2022; 74:506-551. [PMID: 35710135 DOI: 10.1124/pharmrev.121.000408] [Citation(s) in RCA: 143] [Impact Index Per Article: 71.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Acylcarnitines are fatty acid metabolites that play important roles in many cellular energy metabolism pathways. They have historically been used as important diagnostic markers for inborn errors of fatty acid oxidation and are being intensively studied as markers of energy metabolism, deficits in mitochondrial and peroxisomal β -oxidation activity, insulin resistance, and physical activity. Acylcarnitines are increasingly being identified as important indicators in metabolic studies of many diseases, including metabolic disorders, cardiovascular diseases, diabetes, depression, neurologic disorders, and certain cancers. The US Food and Drug Administration-approved drug L-carnitine, along with short-chain acylcarnitines (acetylcarnitine and propionylcarnitine), is now widely used as a dietary supplement. In light of their growing importance, we have undertaken an extensive review of acylcarnitines and provided a detailed description of their identity, nomenclature, classification, biochemistry, pathophysiology, supplementary use, potential drug targets, and clinical trials. We also summarize these updates in the Human Metabolome Database, which now includes information on the structures, chemical formulae, chemical/spectral properties, descriptions, and pathways for 1240 acylcarnitines. This work lays a solid foundation for identifying, characterizing, and understanding acylcarnitines in human biosamples. We also discuss the emerging opportunities for using acylcarnitines as biomarkers and as dietary interventions or supplements for many wide-ranging indications. The opportunity to identify new drug targets involved in controlling acylcarnitine levels is also discussed. SIGNIFICANCE STATEMENT: This review provides a comprehensive overview of acylcarnitines, including their nomenclature, structure and biochemistry, and use as disease biomarkers and pharmaceutical agents. We present updated information contained in the Human Metabolome Database website as well as substantial mapping of the known biochemical pathways associated with acylcarnitines, thereby providing a strong foundation for further clarification of their physiological roles.
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Affiliation(s)
- Maija Dambrova
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Marina Makrecka-Kuka
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Janis Kuka
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Reinis Vilskersts
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Didi Nordberg
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Misty M Attwood
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Stefan Smesny
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Zumrut Duygu Sen
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - An Chi Guo
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Eponine Oler
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Siyang Tian
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Jiamin Zheng
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - David S Wishart
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Edgars Liepinsh
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
| | - Helgi B Schiöth
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia (M.D., M.M.-K., J.K., R.V., E.L.); Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Uppsala, Sweden, (D.N., M.M.A., H.B.S.); Department of Psychiatry, Jena University Hospital, Jena, Germany (S.S., Z.D.S.); and Department of Biological Sciences, University of Alberta, Edmonton, Canada (A.C.G., E.O., S.T., J.Z., D.S.W.)
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3
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Okui T, Iwashita M, Rogers MA, Halu A, Atkins SK, Kuraoka S, Abdelhamid I, Higashi H, Ramsaroop A, Aikawa M, Singh SA, Aikawa E. CROT (Carnitine O-Octanoyltransferase) Is a Novel Contributing Factor in Vascular Calcification via Promoting Fatty Acid Metabolism and Mitochondrial Dysfunction. Arterioscler Thromb Vasc Biol 2021; 41:755-768. [PMID: 33356393 PMCID: PMC8105275 DOI: 10.1161/atvbaha.120.315007] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Vascular calcification is a critical pathology associated with increased cardiovascular event risk, but there are no Food and Drug Administration-approved anticalcific therapies. We hypothesized and validated that an unbiased screening approach would identify novel mediators of human vascular calcification. Approach and Results: We performed an unbiased quantitative proteomics and pathway network analysis that identified increased CROT (carnitine O-octanoyltransferase) in calcifying primary human coronary artery smooth muscle cells (SMCs). Additionally, human carotid artery atherosclerotic plaques contained increased immunoreactive CROT near calcified regions. CROT siRNA reduced fibrocalcific response in calcifying SMCs. In agreement, histidine 327 to alanine point mutation inactivated human CROT fatty acid metabolism enzymatic activity and suppressed SMC calcification. CROT siRNA suppressed type 1 collagen secretion, and restored mitochondrial proteome alterations, and suppressed mitochondrial fragmentation in calcifying SMCs. Lipidomics analysis of SMCs incubated with CROT siRNA revealed increased eicosapentaenoic acid, a vascular calcification inhibitor. CRISPR/Cas9-mediated Crot deficiency in LDL (low-density lipoprotein) receptor-deficient mice reduced aortic and carotid artery calcification without altering bone density or liver and plasma cholesterol and triglyceride concentrations. CONCLUSIONS CROT is a novel contributing factor in vascular calcification via promoting fatty acid metabolism and mitochondrial dysfunction, as such CROT inhibition has strong potential as an antifibrocalcific therapy.
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MESH Headings
- Adult
- Animals
- Atherosclerosis/enzymology
- Atherosclerosis/genetics
- Atherosclerosis/pathology
- Atherosclerosis/prevention & control
- Carnitine Acyltransferases/genetics
- Carnitine Acyltransferases/metabolism
- Cells, Cultured
- Disease Models, Animal
- Energy Metabolism
- Fatty Acids/metabolism
- Female
- Fibrosis
- Humans
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Middle Aged
- Mitochondria/enzymology
- Mitochondria/pathology
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/pathology
- Osteogenesis
- Proteome
- Proteomics
- Receptors, LDL/genetics
- Receptors, LDL/metabolism
- Signal Transduction
- Vascular Calcification/enzymology
- Vascular Calcification/genetics
- Vascular Calcification/pathology
- Vascular Calcification/prevention & control
- Mice
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Affiliation(s)
- Takehito Okui
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Masaya Iwashita
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Maximillian A. Rogers
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Arda Halu
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Samantha K. Atkins
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Shiori Kuraoka
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Ilyes Abdelhamid
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Hideyuki Higashi
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Ashisha Ramsaroop
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Masanori Aikawa
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Center for Excellence in Vascular Biology, Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Sasha A. Singh
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Elena Aikawa
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Center for Excellence in Vascular Biology, Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Department of Human Pathology, Sechenov First Moscow State Medical University, Moscow, 119992, Russia
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4
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Maranha A, Moynihan PJ, Miranda V, Correia Lourenço E, Nunes-Costa D, Fraga JS, José Barbosa Pereira P, Macedo-Ribeiro S, Ventura MR, Clarke AJ, Empadinhas N. Octanoylation of early intermediates of mycobacterial methylglucose lipopolysaccharides. Sci Rep 2015; 5:13610. [PMID: 26324178 PMCID: PMC4555173 DOI: 10.1038/srep13610] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/30/2015] [Indexed: 11/10/2022] Open
Abstract
Mycobacteria synthesize unique intracellular methylglucose lipopolysaccharides (MGLP) proposed to modulate fatty acid metabolism. In addition to the partial esterification of glucose or methylglucose units with short-chain fatty acids, octanoate was invariably detected on the MGLP reducing end. We have identified a novel sugar octanoyltransferase (OctT) that efficiently transfers octanoate to glucosylglycerate (GG) and diglucosylglycerate (DGG), the earliest intermediates in MGLP biosynthesis. Enzymatic studies, synthetic chemistry, NMR spectroscopy and mass spectrometry approaches suggest that, in contrast to the prevailing consensus, octanoate is not esterified to the primary hydroxyl group of glycerate but instead to the C6 OH of the second glucose in DGG. These observations raise important new questions about the MGLP reducing end architecture and about subsequent biosynthetic steps. Functional characterization of this unique octanoyltransferase, whose gene has been proposed to be essential for M. tuberculosis growth, adds new insights into a vital mycobacterial pathway, which may inspire new drug discovery strategies.
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Affiliation(s)
- Ana Maranha
- CNC – Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Patrick J. Moynihan
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada
| | - Vanessa Miranda
- ITQB – Instituto de Tecnologia Química Biológica, Universidade Nova de Lisboa, Portugal
| | - Eva Correia Lourenço
- ITQB – Instituto de Tecnologia Química Biológica, Universidade Nova de Lisboa, Portugal
| | - Daniela Nunes-Costa
- CNC – Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Joana S. Fraga
- IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal
| | - Pedro José Barbosa Pereira
- IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal
| | - Sandra Macedo-Ribeiro
- IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal
| | - M. Rita Ventura
- ITQB – Instituto de Tecnologia Química Biológica, Universidade Nova de Lisboa, Portugal
| | - Anthony J. Clarke
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada
| | - Nuno Empadinhas
- CNC – Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
- III/UC– Instituto de Investigação Interdisciplinar, University of Coimbra, Portugal
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5
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Abstract
Long-chain fatty acyl-coenzyme As (CoAs) are critical regulatory molecules and metabolic intermediates. The initial step in their synthesis is the activation of fatty acids by one of 13 long-chain acyl-CoA synthetase isoforms. These isoforms are regulated independently and have different tissue expression patterns and subcellular locations. Their acyl-CoA products regulate metabolic enzymes and signaling pathways, become oxidized to provide cellular energy, and are incorporated into acylated proteins and complex lipids such as triacylglycerol, phospholipids, and cholesterol esters. Their differing metabolic fates are determined by a network of proteins that channel the acyl-CoAs toward or away from specific metabolic pathways and serve as the basis for partitioning. This review evaluates the evidence for acyl-CoA partitioning by reviewing experimental data on proteins that are believed to contribute to acyl-CoA channeling, the metabolic consequences of loss of these proteins, and the potential role of maladaptive acyl-CoA partitioning in the pathogenesis of metabolic disease and carcinogenesis.
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6
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Fujisawa I, Kitamura Y, Okamoto R, Murayama K, Kato R, Aoki K. Crystal structure of pyrogallol[4]arene complex with phosphocholine: A molecular recognition model for phosphocholine through cation–π interaction. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2013.01.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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7
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Gómez LA, Heath SHD, Hagen TM. Acetyl-L-carnitine supplementation reverses the age-related decline in carnitine palmitoyltransferase 1 (CPT1) activity in interfibrillar mitochondria without changing the L-carnitine content in the rat heart. Mech Ageing Dev 2012; 133:99-106. [PMID: 22322067 DOI: 10.1016/j.mad.2012.01.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Revised: 01/20/2012] [Accepted: 01/24/2012] [Indexed: 12/30/2022]
Abstract
The aging heart displays a loss of bioenergetic reserve capacity partially mediated through lower fatty acid utilization. We investigated whether the age-related impairment of cardiac fatty acid catabolism occurs, at least partially, through diminished levels of L-carnitine, which would adversely affect carnitine palmitoyltransferase 1 (CPT1), the rate-limiting enzyme for fatty acyl-CoA uptake into mitochondria for β-oxidation. Old (24-28 mos) Fischer 344 rats were fed±acetyl-L-carnitine (ALCAR; 1.5% [w/v]) for up to four weeks prior to sacrifice and isolation of cardiac interfibrillar (IFM) and subsarcolemmal (SSM) mitochondria. IFM displayed a 28% (p<0.05) age-related loss of CPT1 activity, which correlated with a decline (41%, p<0.05) in palmitoyl-CoA-driven state 3 respiration. Interestingly, SSM had preserved enzyme function and efficiently utilized palmitate. Analysis of IFM CPT1 kinetics showed both diminished V(max) and K(m) (60% and 49% respectively, p<0.05) when palmitoyl-CoA was the substrate. However, no age-related changes in enzyme kinetics were evident with respect to L-carnitine. ALCAR supplementation restored CPT1 activity in heart IFM, but not apparently through remediation of L-carnitine levels. Rather, ALCAR influenced enzyme activity over time, potentially by modulating conditions in the aging heart that ultimately affect palmitoyl-CoA binding and CPT1 kinetics.
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Affiliation(s)
- Luis A Gómez
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA
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8
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Fujisawa I, Takeuchi D, Kato R, Murayama K, Aoki K. Crystal Structures of Resorcin[4]arene and Tetramethylated Resorcin[4]arene Complexes Incorporating L-Carnitine through Cation–π Interaction. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2011. [DOI: 10.1246/bcsj.20110166] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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9
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Green KD, Porter VR, Zhang Y, Garneau-Tsodikova S. Redesign of Cosubstrate Specificity and Identification of Important Residues for Substrate Binding to hChAT. Biochemistry 2010; 49:6219-27. [DOI: 10.1021/bi1007996] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
| | - Vanessa R. Porter
- Department of Medicinal Chemistry
- Life Sciences Institute, 210 Washtenaw Avenue
| | - Yaru Zhang
- Life Sciences Institute, 210 Washtenaw Avenue
- Chemical Biology Doctoral Program
| | - Sylvie Garneau-Tsodikova
- Department of Medicinal Chemistry
- Life Sciences Institute, 210 Washtenaw Avenue
- Chemical Biology Doctoral Program
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10
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Price NT, Jackson VN, Müller J, Moffat K, Matthews KL, Orton T, Zammit VA. Alternative exon usage in the single CPT1 gene of Drosophila generates functional diversity in the kinetic properties of the enzyme: differential expression of alternatively spliced variants in Drosophila tissues. J Biol Chem 2010; 285:7857-65. [PMID: 20061394 PMCID: PMC2832936 DOI: 10.1074/jbc.m109.072892] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 01/07/2010] [Indexed: 11/06/2022] Open
Abstract
The Drosophila melanogaster genome contains only one CPT1 gene (Jackson, V. N., Cameron, J. M., Zammit, V. A., and Price, N. T. (1999) Biochem. J. 341, 483-489). We have now extended our original observation to all insect genomes that have been sequenced, suggesting that a single CPT1 gene is a universal feature of insect genomes. We hypothesized that insects may be able to generate kinetically distinct variants by alternative splicing of their single CPT1 gene. Analysis of the insect genomes revealed that (a) the single CPT1 gene in each and every insect genome contains two alternative exons and (ii) in all cases, the putative alternative splicing site occurs within a small region corresponding to 21 amino acid residues that are known to be essential for the binding of substrates and of malonyl-CoA in mammalian CPT1A. We performed PCR analyses of mRNA from different Drosophila tissues; both of the anticipated splice variants of CPT1 mRNA were found to be expressed in all of the tissues tested (both in larvae and adults), with the expression level for one of the splice variants being significantly different between flight muscle and the fat body of adult Drosophila. Heterologous expression of the full-length cDNAs corresponding to the two putative variants of Drosophila CPT1 in the yeast Pichia pastoris revealed two important differences between the properties of the two variants: (i) their affinity (K(0.5)) for one of the substrates, palmitoyl-CoA, differed by 5-fold, and (ii) the sensitivity to inhibition by malonyl-CoA at fixed, higher palmitoyl-CoA concentrations was 2-fold different and associated with different kinetics of inhibition. These data indicate that alternative splicing that specifically affects a structurally crucial region of the protein is an important mechanism through which functional diversity of CPT1 kinetics is generated from the single gene that occurs in insects.
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Affiliation(s)
| | | | | | - Kevin Moffat
- the Department of Biological Sciences, University of Warwick, Gibbett Hill Road, Coventry CV4 7AL, United Kingdom
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11
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Site-directed mutagenesis of the His residues of the rat mitochondrial carnitine/acylcarnitine carrier: Implications for the role of His-29 in the transport pathway. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:1009-15. [DOI: 10.1016/j.bbabio.2009.02.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 02/20/2009] [Accepted: 02/23/2009] [Indexed: 11/21/2022]
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12
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Mera P, Bentebibel A, López-Viñas E, Cordente AG, Gurunathan C, Sebastián D, Vázquez I, Herrero L, Ariza X, Gómez-Puertas P, Asins G, Serra D, García J, Hegardt FG. C75 is converted to C75-CoA in the hypothalamus, where it inhibits carnitine palmitoyltransferase 1 and decreases food intake and body weight. Biochem Pharmacol 2008; 77:1084-95. [PMID: 19094968 DOI: 10.1016/j.bcp.2008.11.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Revised: 11/12/2008] [Accepted: 11/20/2008] [Indexed: 10/21/2022]
Abstract
Central nervous system administration of C75 produces hypophagia and weight loss in rodents identifying C75 as a potential drug against obesity and type 2 diabetes. However, the mechanism underlying this effect is unknown. Here we show that C75-CoA is generated chemically, in vitro and in vivo from C75 and that it is a potent inhibitor of carnitine palmitoyltranferase 1 (CPT1), the rate-limiting step of fatty-acid oxidation. Three-D docking and kinetic analysis support the inhibitory effect of C75-CoA on CPT1. Central nervous system administration of C75 in rats led to C75-CoA production, inhibition of CPT1 and lower body weight and food intake. Our results suggest that inhibition of CPT1, and thus increased availability of fatty acids in the hypothalamus, contribute to the pharmacological mechanism of C75 to decrease food intake.
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Affiliation(s)
- Paula Mera
- Department of Biochemistry and Molecular Biology and IBUB (Institute of Biomedicine University of Barcelona), Spain
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13
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Corti S, Bordoni A, Ronchi D, Musumeci O, Aguennouz M, Toscano A, Lamperti C, Bresolin N, Comi GP. Clinical features and new molecular findings in Carnitine Palmitoyltransferase II (CPT II) deficiency. J Neurol Sci 2007; 266:97-103. [PMID: 17936304 DOI: 10.1016/j.jns.2007.09.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 08/31/2007] [Accepted: 09/06/2007] [Indexed: 11/19/2022]
Abstract
Carnitine palmitoyltransferase II (CPT II) deficiency is the most common inherited disorder of lipid metabolism characterized in its adult form by attacks of myalgia and myoglobinuria. We analyzed a cohort of 22 CPT II-deficient patients (representing 20 independent probands) to correlate clinical presentation and molecular data. The common p.Ser113Leu mutation was detected with an allelic frequency of 67.5% (27/40), in association with mild adult-onset phenotype. In addition to the p.Ser113Leu mutation, other 10 disease-causing mutations were identified, 5 of which were novel. They are a micro-insertion within exon 5, three aminoacid substitutions within the coding region, namely p.Arg151Trp, p.Asp576Gly, p.Arg247Trp and a truncating stop codon mutation (p.Arg554Ter). Our data expand the spectrum of CPT II mutations and help to evaluate possible correlations between genotypes and phenotypes.
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Affiliation(s)
- S Corti
- Dino Ferrari Centre, Department of Neurological Sciences, University of Milan, IRCCS, Foundation Ospedale Maggiore Policlinico Mangiagalli and Regina Elena, Milan, Italy
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14
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Faye A, Esnous C, Price NT, Onfray MA, Girard J, Prip-Buus C. Rat Liver Carnitine Palmitoyltransferase 1 Forms an Oligomeric Complex within the Outer Mitochondrial Membrane. J Biol Chem 2007; 282:26908-26916. [PMID: 17650509 DOI: 10.1074/jbc.m705418200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Carnitine palmitoyltransferase (CPT) 1A catalyzes the rate-limiting step in the transport of long chain acyl-CoAs from cytoplasm to the mitochondrial matrix by converting them to acylcarnitines. Located within the outer mitochondrial membrane, CPT1A activity is inhibited by malonyl-CoA, its allosteric inhibitor. In this study, we investigate for the first time the quaternary structure of rat CPT1A. Chemical cross-linking studies using intact mitochondria isolated from fed rat liver or from Saccharomyces cerevisiae expressing CPT1A show that CPT1A self-assembles into an oligomeric complex. Size exclusion chromatography experiments using solubilized mitochondrial extracts suggest that the fundamental unit of its quaternary structure is a trimer. When studied in blue native-PAGE, the CPT1A hexamer could be observed, however, suggesting that under these native conditions CPT1A trimers might be arranged as dimers. Moreover, the oligomeric state of CPT1A was found unchanged by starvation and by streptozotocin-induced diabetes, conditions characterized by changes in malonyl-CoA sensitivity of CPT1A. Finally, gel filtration analysis of several yeast-expressed chimeric CPTs demonstrates that the first 147 N-terminal residues of CPT1A, encompassing its two transmembrane segments, trigger trimerization independently of its catalytic C-terminal domain. Deletion of residues 1-82, including transmembrane 1, did not abrogate oligomerization, but the latter is limited to a trimer by the presence of the large catalytic C-terminal domain on the cytosolic face of mitochondria. Based on these findings, we proposed that the oligomeric structure of CPT1A would allow the newly formed acylcarnitines to gain direct access into the intermembrane space, hence facilitating substrate channeling.
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Affiliation(s)
- Audrey Faye
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), 75014 Paris, France; INSERM, U567, Paris 75014, France
| | - Catherine Esnous
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), 75014 Paris, France; INSERM, U567, Paris 75014, France
| | - Nigel T Price
- Department of Cell Biochemistry, Hannah Research Institute, Ayr KA6 5HL, Scotland, United Kingdom
| | - Marie Anne Onfray
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), 75014 Paris, France; INSERM, U567, Paris 75014, France
| | - Jean Girard
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), 75014 Paris, France; INSERM, U567, Paris 75014, France
| | - Carina Prip-Buus
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), 75014 Paris, France; INSERM, U567, Paris 75014, France.
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15
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López-Viñas E, Bentebibel A, Gurunathan C, Morillas M, de Arriaga D, Serra D, Asins G, Hegardt FG, Gómez-Puertas P. Definition by functional and structural analysis of two malonyl-CoA sites in carnitine palmitoyltransferase 1A. J Biol Chem 2007; 282:18212-18224. [PMID: 17452323 DOI: 10.1074/jbc.m700885200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Carnitine palmitoyltransferase 1 (CPT1) catalyzes the conversion of palmitoyl-CoA to palmitoylcarnitine in the presence of l-carnitine, thus facilitating the entry of fatty acids to mitochondria, in a process that is physiologically inhibited by malonyl-CoA. To examine the mechanism of CPT1 liver isoform (CPT1A) inhibition by malonyl-CoA, we constructed an in silico model of both its NH2- and COOH-terminal domains. Two malonyl-CoA binding sites were found. One of these, the "CoA site" or "A site," is involved in the interactions between NH2- and COOH-terminal domains and shares the acyl-CoA hemitunnel. The other, the "opposite-to-CoA site" or "O site," is on the opposite side of the enzyme, in the catalytic channel. The two sites share the carnitine-binding locus. To prevent the interaction between NH2- and COOH-terminal regions, we produced CPT1A E26K and K561E mutants. A double mutant E26K/K561E (swap), which was expected to conserve the interaction, was also produced. Inhibition assays showed a 12-fold decrease in the sensitivity (IC50) toward malonyl-CoA for CPT1A E26K and K561E single mutants, whereas swap mutant reverts to wild-type IC50 value. We conclude that structural interaction between both domains is critical for enzyme sensitivity to malonyl-CoA inhibition at the "A site." The location of the "O site" for malonyl-CoA binding was supported by inhibition assays of expressed R243T mutant. The model is also sustained by kinetic experiments that indicated linear mixed type malonyl-CoA inhibition for carnitine. Malonyl-CoA alters the affinity of carnitine, and there appears to be an exponential inverse relation between carnitine Km and malonyl-CoA IC50.
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Affiliation(s)
- Eduardo López-Viñas
- Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Cantoblanco, E-28049 Madrid, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Assia Bentebibel
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Chandrashekaran Gurunathan
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Montserrat Morillas
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Dolores de Arriaga
- Departamento de Biología Molecular, Universidad de León, E-24071 León, Spain
| | - Dolors Serra
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Guillermina Asins
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
| | - Fausto G Hegardt
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Barcelona, E-08028 Barcelona, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain.
| | - Paulino Gómez-Puertas
- Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Cantoblanco, E-28049 Madrid, Spain; CIBER Institute of Fisiopatología de la Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, 28049 Madrid, Spain
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16
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Isackson PJ, Bennett MJ, Vladutiu GD. Identification of 16 new disease-causing mutations in the CPT2 gene resulting in carnitine palmitoyltransferase II deficiency. Mol Genet Metab 2006; 89:323-31. [PMID: 16996287 DOI: 10.1016/j.ymgme.2006.08.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2006] [Revised: 08/09/2006] [Accepted: 08/09/2006] [Indexed: 11/24/2022]
Abstract
The exonic regions of the carnitine palmitoyltransferase 2 (CPT2) gene were characterized from 101 patients with defined clinical and biochemical evidence for the adult onset form of CPT II deficiency and in 2 patients detected as newborns with abnormal acylcarnitine profiles. Twenty-seven disease-causing mutations within the CPT2 gene were identified in this cohort, 16 of which were novel. A total of 60 disease-causing mutations have been identified to date in CPT2 and 41 of these are predicted to produce amino acid substitution/deletions. The implications of these mutations are described in light of recent advances in our understanding of the molecular structure of members of the carnitine acyltransferase family.
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Affiliation(s)
- Paul J Isackson
- Department of Pediatrics, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14209, USA
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17
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Hsiao YS, Jogl G, Tong L. Crystal structures of murine carnitine acetyltransferase in ternary complexes with its substrates. J Biol Chem 2006; 281:28480-7. [PMID: 16870616 PMCID: PMC2940834 DOI: 10.1074/jbc.m602622200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Carnitine acyltransferases catalyze the reversible exchange of acyl groups between coenzyme A (CoA) and carnitine. They have important roles in many cellular processes, especially the oxidation of long-chain fatty acids in the mitochondria for energy production, and are attractive targets for drug discovery against diabetes and obesity. To help define in molecular detail the catalytic mechanism of these enzymes, we report here the high resolution crystal structure of wild-type murine carnitine acetyltransferase (CrAT) in a ternary complex with its substrates acetyl-CoA and carnitine, and the structure of the S554A/M564G double mutant in a ternary complex with the substrates CoA and hexanoylcarnitine. Detailed analyses suggest that these structures may be good mimics for the Michaelis complexes for the forward and reverse reactions of the enzyme, representing the first time that such complexes of CrAT have been studied in molecular detail. The structural information provides significant new insights into the catalytic mechanism of CrAT and possibly carnitine acyltransferases in general.
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Affiliation(s)
- Yu-Shan Hsiao
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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18
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Rufer AC, Thoma R, Benz J, Stihle M, Gsell B, De Roo E, Banner DW, Mueller F, Chomienne O, Hennig M. The crystal structure of carnitine palmitoyltransferase 2 and implications for diabetes treatment. Structure 2006; 14:713-23. [PMID: 16615913 DOI: 10.1016/j.str.2006.01.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Revised: 12/20/2005] [Accepted: 01/27/2006] [Indexed: 10/24/2022]
Abstract
Carnitine palmitoyltransferases 1 and 2 (CPTs) facilitate the import of long-chain fatty acids into mitochondria. Modulation of the catalytic activity of the CPT system is currently under investigation for the development of novel drugs against diabetes mellitus. We report here the 1.6 A resolution structure of the full-length mitochondrial membrane protein CPT-2. The structure of CPT-2 in complex with the generic CPT inhibitor ST1326 ([R]-N-[tetradecylcarbamoyl]-aminocarnitine), a substrate analog mimicking palmitoylcarnitine and currently in clinical trials for diabetes mellitus treatment, was solved at 2.5 A resolution. These structures of CPT-2 provide insight into the function of residues involved in substrate binding and determination of substrate specificity, thereby facilitating the rational design of antidiabetic drugs. We identify a sequence insertion found in CPT-2 that mediates membrane localization. Mapping of mutations described for CPT-2 deficiency, a hereditary disorder of lipid metabolism, implies effects on substrate recognition and structural integrity of CPT-2.
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Affiliation(s)
- Arne C Rufer
- F. Hoffmann-La Roche AG, Pharma Research Discovery, 4070 Basel, Switzerland
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19
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Hsiao YS, Jogl G, Esser V, Tong L. Crystal structure of rat carnitine palmitoyltransferase II (CPT-II). Biochem Biophys Res Commun 2006; 346:974-80. [PMID: 16781677 PMCID: PMC2937350 DOI: 10.1016/j.bbrc.2006.06.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Accepted: 06/01/2006] [Indexed: 11/25/2022]
Abstract
Carnitine palmitoyltransferase II (CPT-II) has a crucial role in the beta-oxidation of long-chain fatty acids in mitochondria. We report here the crystal structure of rat CPT-II at 1.9A resolution. The overall structure shares strong similarity to those of short- and medium-chain carnitine acyltransferases, although detailed structural differences in the active site region have a significant impact on the substrate selectivity of CPT-II. Three aliphatic chains, possibly from a detergent that is used for the crystallization, were found in the structure. Two of them are located in the carnitine and CoA binding sites, respectively. The third aliphatic chain may mimic the long-chain acyl group in the substrate of CPT-II. The binding site for this aliphatic chain does not exist in the short- and medium-chain carnitine acyltransferases, due to conformational differences among the enzymes. A unique insert in CPT-II is positioned on the surface of the enzyme, with a highly hydrophobic surface. It is likely that this surface patch mediates the association of CPT-II with the inner membrane of the mitochondria.
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Affiliation(s)
- Yu-Shan Hsiao
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Gerwald Jogl
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Victoria Esser
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027
- Corresponding author. Phone: (212) 854-5203; FAX: (212) 865-8246,
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20
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Bentebibel A, Sebastián D, Herrero L, López-Viñas E, Serra D, Asins G, Gómez-Puertas P, Hegardt FG. Novel effect of C75 on carnitine palmitoyltransferase I activity and palmitate oxidation. Biochemistry 2006; 45:4339-50. [PMID: 16584169 DOI: 10.1021/bi052186q] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
C75 is a potential drug for the treatment of obesity. It was first identified as a competitive, irreversible inhibitor of fatty acid synthase (FAS). It has also been described as a malonyl-CoA analogue that antagonizes the allosteric inhibitory effect of malonyl-CoA on carnitine palmitoyltransferase I (CPT I), the main regulatory enzyme involved in fatty acid oxidation. On the basis of MALDI-TOF analysis, we now provide evidence that C75 can be transformed to its C75-CoA derivative. Unlike the activation produced by C75, the CoA derivative is a potent competitive inhibitor that binds tightly but reversibly to CPT I. IC50 values for yeast-overexpressed L- or M-CPT I isoforms, as well as for purified mitochondria from rat liver and muscle, were within the same range as those observed for etomoxiryl-CoA, a potent inhibitor of CPT I. When a pancreatic INS(823/13), muscle L6E9, or kidney HEK293 cell line was incubated directly with C75, fatty acid oxidation was inhibited. This suggests that C75 could be transformed in the cell to its C75-CoA derivative, inhibiting CPT I activity and consequently fatty acid oxidation. In vivo, a single intraperitoneal injection of C75 in mice produced short-term inhibition of CPT I activity in mitochondria from the liver, soleus, and pancreas, indicating that C75 could be transformed to its C75-CoA derivative in these tissues. Finally, in silico molecular docking studies showed that C75-CoA occupies the same pocket in CPT I as palmitoyl-CoA, suggesting an inhibiting mechanism based on mutual exclusion. Overall, our results describe a novel role for C75 in CPT I activity, highlighting the inhibitory effect of its C75-CoA derivative.
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Affiliation(s)
- Assia Bentebibel
- Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Barcelona, E-08028 Barcelona, Spain
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21
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Cordente AG, López-Viñas E, Vázquez MI, Gómez-Puertas P, Asins G, Serra D, Hegardt FG. Mutagenesis of Specific Amino Acids Converts Carnitine Acetyltransferase into Carnitine Palmitoyltransferase. Biochemistry 2006; 45:6133-41. [PMID: 16681386 DOI: 10.1021/bi0602664] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Carnitine acyltransferases catalyze the exchange of acyl groups between carnitine and CoA. The members of the family can be classified on the basis of their acyl-CoA selectivity. Carnitine acetyltransferases (CrATs) are very active toward short-chain acyl-CoAs but not toward medium- or long-chain acyl-CoAs. Previously, we identified an amino acid residue (Met(564) in rat CrAT) that was critical to fatty acyl-chain-length specificity. M564G-mutated CrAT behaved as if its natural substrates were medium-chain acyl-CoAs, similar to that of carnitine octanoyltransferase (COT). To extend the specificity of rat CrAT to other substrates, we have performed new mutations. Using in silico molecular modeling procedures, we have now identified a second putative amino acid involved in acyl-CoA specificity (Asp(356) in rat CrAT). The double CrAT mutant D356A/M564G showed 6-fold higher activity toward palmitoyl-CoA than that of the single CrAT mutant M564G and a new activity toward stearoyl-CoA. We show that by performing two amino acid replacements a CrAT can be converted into a pseudo carnitine palmitoyltransferase (CPT) in terms of substrate specificity. To change CrAT specificity from carnitine to choline, we also prepared a mutant CrAT that incorporates four amino acid substitutions (A106M/T465V/T467N/R518N). The quadruple mutant shifted the catalytic discrimination between l-carnitine and choline in favor of the latter substrate and showed a 9-fold increase in catalytic efficiency toward choline compared with that of the wild-type. Molecular in silico docking supports kinetic data for the positioning of substrates in the catalytic site of CrAT mutants.
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Affiliation(s)
- Antonio G Cordente
- Department of Biochemistry and Molecular Biology, School of Pharmacy, University of Barcelona, E-08028 Spain
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22
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Gandour RD. Rationalizing the Solution Properties of Zwitterions by Means of Computational Chemistry. Chem Biodivers 2005; 2:1580-94. [PMID: 17191957 DOI: 10.1002/cbdv.200590129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This short review describes our computational studies of carnitine, acetylcarnitines, and betaines over the past two decades. Interspersed among the three computational studies--a molecular mechanics study of the conformer population of carnitine and acetylcarnitine, an AM1 study of the energetics of hydrolysis of acetylcarnitine, and an HF 6-31G* study of the solvation energies and structures of a homologous series of betaines--are brief overviews of our research in designing and testing new therapeutic agents for non-insulin dependent diabetes and for protection against sexually transmitted diseases. The three studies also show how computational chemistry has evolved during this time to enable an evaluation of the structure and energetics of zwitterions in aqueous solution.
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Affiliation(s)
- Richard D Gandour
- Department of Chemistry (MC 0212), Virginia Tech, Blacksburg, VA 24061, USA.
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