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Krumm CS, Landzberg RS, Ramos-Espiritu L, Adura C, Liu X, Acuna M, Xie Y, Xu X, Tillman MC, Li Y, Glickman JF, Ortlund EA, Ginn JD, Cohen DE. High-throughput screening identifies small molecule inhibitors of thioesterase superfamily member 1: Implications for the management of non-alcoholic fatty liver disease. Mol Metab 2023; 78:101832. [PMID: 38403978 PMCID: PMC10663673 DOI: 10.1016/j.molmet.2023.101832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/24/2023] [Accepted: 10/24/2023] [Indexed: 02/27/2024] Open
Abstract
OBJECTIVE Thioesterase superfamily member 1 (Them1) is a long chain acyl-CoA thioesterase comprising two N-terminal HotDog fold enzymatic domains linked to a C-terminal lipid-sensing steroidogenic acute regulatory transfer-related (START) domain, which allosterically modulates enzymatic activity. Them1 is highly expressed in thermogenic adipose tissue, where it functions to suppress energy expenditure by limiting rates of fatty acid oxidation, and is induced markedly in liver in response to high fat feeding, where it suppresses fatty acid oxidation and promotes glucose production. Them1-/- mice are protected against non-alcoholic fatty liver disease (NAFLD), suggesting Them1 as a therapeutic target. METHODS A high-throughput small molecule screen was performed to identify promising inhibitors targeting the fatty acyl-CoA thioesterase activity of purified recombinant Them1.Counter screening was used to determine specificity for Them1 relative to other acyl-CoA thioesterase isoforms. Inhibitor binding and enzyme inhibition were quantified by biophysical and biochemical approaches, respectively. Following structure-based optimization, lead compounds were tested in cell culture. RESULTS Two lead allosteric inhibitors were identified that selectively inhibited Them1 by binding the START domain. In mouse brown adipocytes, these inhibitors promoted fatty acid oxidation, as evidenced by increased oxygen consumption rates. In mouse hepatocytes, they promoted fatty acid oxidation, but also reduced glucose production. CONCLUSION Them1 inhibitors could prove attractive for the pharmacologic management of NAFLD.
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Affiliation(s)
- Christopher S Krumm
- Division of Gastroenterology & Hepatology, Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Sanders Tri-Institutional Therapeutics Discovery Institute, New York, NY 10065, USA
| | - Renée S Landzberg
- Division of Gastroenterology & Hepatology, Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | | | - Carolina Adura
- Fisher Drug Discovery Resource Center, The Rockefeller University, New York, NY 10065, USA
| | - Xu Liu
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Mariana Acuna
- Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Yang Xie
- Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Xu Xu
- Division of Gastroenterology & Hepatology, Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Division of Surgical Sciences, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Matthew C Tillman
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Yingxia Li
- Division of Gastroenterology & Hepatology, Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - J Fraser Glickman
- Fisher Drug Discovery Resource Center, The Rockefeller University, New York, NY 10065, USA
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - John D Ginn
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, NY 10065, USA
| | - David E Cohen
- Division of Gastroenterology & Hepatology, Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Division of Gastroenterology, Hepatology and Endoscopy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
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Bekeova C, Han JI, Xu H, Kerr E, Blackburne B, Lynch SC, Mesaros C, Murgia M, Vadigepalli R, Beld J, Leonardi R, Snyder NW, Seifert EL. Acyl-CoA thioesterase-2 facilitates β-oxidation in glycolytic skeletal muscle in a lipid supply dependent manner. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.27.546724. [PMID: 37425757 PMCID: PMC10327053 DOI: 10.1101/2023.06.27.546724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Acyl-Coenzyme A (acyl-CoA) thioesters are compartmentalized intermediates that participate in in multiple metabolic reactions within the mitochondrial matrix. The limited availability of free CoA (CoASH) in the matrix raises the question of how the local acyl-CoA concentration is regulated to prevent trapping of CoASH from overload of any specific substrate. Acyl-CoA thioesterase-2 (ACOT2) hydrolyzes long-chain acyl-CoAs to their constituent fatty acids and CoASH, and is the only mitochondrial matrix ACOT refractory to inhibition by CoASH. Thus, we reasoned that ACOT2 may constitutively regulate matrix acyl-CoA levels. Acot2 deletion in murine skeletal muscle (SM) resulted in acyl-CoA build-up when lipid supply and energy demands were modest. When energy demand and pyruvate availability were elevated, lack of ACOT2 activity promoted glucose oxidation. This preference for glucose over fatty acid oxidation was recapitulated in C2C12 myotubes with acute depletion of Acot2 , and overt inhibition of β-oxidation was demonstrated in isolated mitochondria from Acot2 -depleted glycolytic SM. In mice fed a high fat diet, ACOT2 enabled the accretion of acyl-CoAs and ceramide derivatives in glycolytic SM, and this was associated with worse glucose homeostasis compared to when ACOT2 was absent. These observations suggest that ACOT2 supports CoASH availability to facilitate β-oxidation in glycolytic SM when lipid supply is modest. However, when lipid supply is high, ACOT2 enables acyl-CoA and lipid accumulation, CoASH sequestration, and poor glucose homeostasis. Thus, ACOT2 regulates matrix acyl-CoA concentration in glycolytic muscle, and its impact depends on lipid supply.
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Koves TR, Zhang GF, Davidson MT, Chaves AB, Crown SB, Johnson JM, Slentz DH, Grimsrud PA, Muoio DM. Pyruvate-supported flux through medium-chain ketothiolase promotes mitochondrial lipid tolerance in cardiac and skeletal muscles. Cell Metab 2023:S1550-4131(23)00094-3. [PMID: 37060901 DOI: 10.1016/j.cmet.2023.03.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 02/07/2023] [Accepted: 03/24/2023] [Indexed: 04/17/2023]
Abstract
Even-chain acylcarnitine (AC) metabolites, most of which are generated as byproducts of incomplete fatty acid oxidation (FAO), are viewed as biomarkers of mitochondrial lipid stress attributable to one or more metabolic bottlenecks in the β-oxidation pathway. The origins and functional implications of FAO bottlenecks remain poorly understood. Here, we combined a sophisticated mitochondrial phenotyping platform with state-of-the-art molecular profiling tools and multiple two-state mouse models of respiratory function to uncover a mechanism that connects AC accumulation to lipid intolerance, metabolic inflexibility, and respiratory inefficiency in skeletal muscle mitochondria. These studies also identified a short-chain carbon circuit at the C4 node of FAO wherein reverse flux of glucose-derived acetyl CoA through medium-chain ketothiolase enhances lipid tolerance and redox stability in heart mitochondria by regenerating free CoA and NAD+. The findings help to explain why diminished FAO capacity, AC accumulation, and metabolic inflexibility are tightly linked to poor health outcomes.
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Affiliation(s)
- Timothy R Koves
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Division of Geriatrics, Duke University Medical Center, Durham, NC 27710, USA
| | - Guo-Fang Zhang
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael T Davidson
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27701, USA
| | - Alec B Chaves
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27701, USA
| | - Scott B Crown
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27701, USA
| | - Jordan M Johnson
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27701, USA
| | - Dorothy H Slentz
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27701, USA
| | - Paul A Grimsrud
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, NC 27710, USA
| | - Deborah M Muoio
- Duke Molecular Physiology Institute and Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, NC 27710, USA; Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA.
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Caswell BT, de Carvalho CC, Nguyen H, Roy M, Nguyen T, Cantu DC. Thioesterase enzyme families: Functions, structures, and mechanisms. Protein Sci 2022; 31:652-676. [PMID: 34921469 PMCID: PMC8862431 DOI: 10.1002/pro.4263] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/11/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022]
Abstract
Thioesterases are enzymes that hydrolyze thioester bonds in numerous biochemical pathways, for example in fatty acid synthesis. This work reports known functions, structures, and mechanisms of updated thioesterase enzyme families, which are classified into 35 families based on sequence similarity. Each thioesterase family is based on at least one experimentally characterized enzyme, and most families have enzymes that have been crystallized and their tertiary structure resolved. Classifying thioesterases into families allows to predict tertiary structures and infer catalytic residues and mechanisms of all sequences in a family, which is particularly useful because the majority of known protein sequence have no experimental characterization. Phylogenetic analysis of experimentally characterized thioesterases that have structures with the two main structural folds reveal convergent and divergent evolution. Based on tertiary structure superimposition, catalytic residues are predicted.
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Affiliation(s)
- Benjamin T. Caswell
- Department of Chemical and Materials EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Caio C. de Carvalho
- Department of Chemical and Materials EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Hung Nguyen
- Department of Computer Science and EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Monikrishna Roy
- Department of Computer Science and EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - Tin Nguyen
- Department of Computer Science and EngineeringUniversity of Nevada, RenoRenoNevadaUSA
| | - David C. Cantu
- Department of Chemical and Materials EngineeringUniversity of Nevada, RenoRenoNevadaUSA
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5
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Tillman MC, Imai N, Li Y, Khadka M, Okafor CD, Juneja P, Adhiyaman A, Hagen SJ, Cohen DE, Ortlund EA. Allosteric regulation of thioesterase superfamily member 1 by lipid sensor domain binding fatty acids and lysophosphatidylcholine. Proc Natl Acad Sci U S A 2020; 117:22080-22089. [PMID: 32820071 PMCID: PMC7486800 DOI: 10.1073/pnas.2003877117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nonshivering thermogenesis occurs in brown adipose tissue to generate heat in response to cold ambient temperatures. Thioesterase superfamily member 1 (Them1) is transcriptionally up-regulated in brown adipose tissue upon exposure to the cold and suppresses thermogenesis in order to conserve energy reserves. It hydrolyzes long-chain fatty acyl-CoAs that are derived from lipid droplets, preventing their use as fuel for thermogenesis. In addition to its enzymatic domains, Them1 contains a C-terminal StAR-related lipid transfer (START) domain with unknown ligand or function. By complementary biophysical approaches, we show that the START domain binds to long-chain fatty acids, products of Them1's enzymatic reaction, as well as lysophosphatidylcholine (LPC), lipids shown to activate thermogenesis in brown adipocytes. Certain fatty acids stabilize the START domain and allosterically enhance Them1 catalysis of acyl-CoA, whereas 18:1 LPC destabilizes and inhibits activity, which we verify in cell culture. Additionally, we demonstrate that the START domain functions to localize Them1 near lipid droplets. These findings define the role of the START domain as a lipid sensor that allosterically regulates Them1 activity and spatially localizes it in proximity to the lipid droplet.
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Affiliation(s)
- Matthew C Tillman
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Norihiro Imai
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10065
| | - Yue Li
- Department of Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215
| | - Manoj Khadka
- Emory Integrated Lipidomics Core, Emory University, Atlanta, GA 30322
| | - C Denise Okafor
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Puneet Juneja
- Robert P. Apkarian Integrated Electron Microscopy Core, Emory University, Atlanta, GA 30322
| | - Akshitha Adhiyaman
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Susan J Hagen
- Department of Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215
| | - David E Cohen
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10065
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322;
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6
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Le CH, Benage LG, Specht KS, Li Puma LC, Mulligan CM, Heuberger AL, Prenni JE, Claypool SM, Chatfield KC, Sparagna GC, Chicco AJ. Tafazzin deficiency impairs CoA-dependent oxidative metabolism in cardiac mitochondria. J Biol Chem 2020; 295:12485-12497. [PMID: 32665401 DOI: 10.1074/jbc.ra119.011229] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 07/07/2020] [Indexed: 12/20/2022] Open
Abstract
Barth syndrome is a mitochondrial myopathy resulting from mutations in the tafazzin (TAZ) gene encoding a phospholipid transacylase required for cardiolipin remodeling. Cardiolipin is a phospholipid of the inner mitochondrial membrane essential for the function of numerous mitochondrial proteins and processes. However, it is unclear how tafazzin deficiency impacts cardiac mitochondrial metabolism. To address this question while avoiding confounding effects of cardiomyopathy on mitochondrial phenotype, we utilized Taz-shRNA knockdown (TazKD ) mice, which exhibit defective cardiolipin remodeling and respiratory supercomplex instability characteristic of human Barth syndrome but normal cardiac function into adulthood. Consistent with previous reports from other models, mitochondrial H2O2 emission and oxidative damage were greater in TazKD than in wild-type (WT) hearts, but there were no differences in oxidative phosphorylation coupling efficiency or membrane potential. Fatty acid and pyruvate oxidation capacities were 40-60% lower in TazKD mitochondria, but an up-regulation of glutamate oxidation supported respiration rates approximating those with pyruvate and palmitoylcarnitine in WT. Deficiencies in mitochondrial CoA and shifts in the cardiac acyl-CoA profile paralleled changes in fatty acid oxidation enzymes and acyl-CoA thioesterases, suggesting limitations of CoA availability or "trapping" in TazKD mitochondrial metabolism. Incubation of TazKD mitochondria with exogenous CoA partially rescued pyruvate and palmitoylcarnitine oxidation capacities, implicating dysregulation of CoA-dependent intermediary metabolism rather than respiratory chain defects in the bioenergetic impacts of tafazzin deficiency. These findings support links among cardiolipin abnormalities, respiratory supercomplex instability, and mitochondrial oxidant production and shed new light on the distinct metabolic consequences of tafazzin deficiency in the mammalian heart.
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Affiliation(s)
- Catherine H Le
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, Colorado, USA
| | - Lindsay G Benage
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Kalyn S Specht
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Lance C Li Puma
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Christopher M Mulligan
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, Colorado, USA
| | - Adam L Heuberger
- Department of Horticulture and Landscape Architecture, Colorado State University, Fort Collins, Colorado, USA
| | - Jessica E Prenni
- Department of Horticulture and Landscape Architecture, Colorado State University, Fort Collins, Colorado, USA
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kathryn C Chatfield
- Department of Pediatrics, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, Colorado, USA
| | - Genevieve C Sparagna
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Adam J Chicco
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, Colorado, USA .,Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.,Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, Colorado, USA
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7
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Swarbrick CMD, Nanson JD, Patterson EI, Forwood JK. Structure, function, and regulation of thioesterases. Prog Lipid Res 2020; 79:101036. [PMID: 32416211 DOI: 10.1016/j.plipres.2020.101036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 01/15/2023]
Abstract
Thioesterases are present in all living cells and perform a wide range of important biological functions by catalysing the cleavage of thioester bonds present in a diverse array of cellular substrates. Thioesterases are organised into 25 families based on their sequence conservation, tertiary and quaternary structure, active site configuration, and substrate specificity. Recent structural and functional characterisation of thioesterases has led to significant changes in our understanding of the regulatory mechanisms that govern enzyme activity and their respective cellular roles. The resulting dogma changes in thioesterase regulation include mechanistic insights into ATP and GDP-mediated regulation by oligomerisation, the role of new key regulatory regions, and new insights into a conserved quaternary structure within TE4 family members. Here we provide a current and comparative snapshot of our understanding of thioesterase structure, function, and regulation across the different thioesterase families.
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Affiliation(s)
| | - Jeffrey D Nanson
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience, Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Edward I Patterson
- Centre for Neglected Tropical Diseases, Departments of Vector Biology and Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, New South Wales, Australia.
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8
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de Brun V, Loor JJ, Naya H, Vailati-Riboni M, Bulgari O, Shahzad K, Abecia JA, Sosa C, Meikle A. The embryo affects day 14 uterine transcriptome depending on nutritional status in sheep. a. Metabolic adaptation to pregnancy in nourished and undernourished ewes. Theriogenology 2020; 146:14-19. [PMID: 32036055 DOI: 10.1016/j.theriogenology.2020.01.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/20/2019] [Accepted: 01/26/2020] [Indexed: 12/16/2022]
Abstract
This study investigated the effects of undernutrition and the presence of the conceptus at the time of maternal recognition of pregnancy on the expression of uterine indicators of metabolism in ewes. Adult Rasa Aragonesa ewes were allocated to one of two planes of nutrition for 28 days: maintenance energy intake (control; 5 cyclic and 6 pregnant ewes) providing 7.8 MJ of metabolisable energy, and 0.5 maintenance intake (undernourished; 6 cyclic and 7 pregnant ewes) providing 3.9 MJ of metabolisable energy per ewe. RNA from intercaruncular uterine tissue was harvested at slaughter on Day 14 of estrous cycle or pregnancy, and hybridized to the Agilent 15K Sheep Microarray chip. Functional bioinformatics analyses were performed using PANTHER (Protein ANalysis THrough Evolutionary Relationships) Classification System. The presence of the embryo upregulated expression of genes encoding peptide and monocarboxylate transporters regardless of nutritional treatment, although the degree of gene expression was lower in undernourished ewes. Genes encoding enzymes involved in glycolysis were downregulated both in pregnant control and undernourished ewes, probably as a compensatory mechanism for the increased glucose transport to the uterus. Compared with control cyclic ewes, control pregnant ewes had greater expression of genes involved in oxidation of fatty acids, suggesting increased uterine energy demands. This was not observed in undernourished pregnant animals when compared to undernourished cyclic ewes; nevertheless, those animals had lower uterine expression of enzymes involved in fatty acid biosynthesis. The presence of the embryo upregulated genes involved in electron transport probably as a result of increased energy demands for pregnancy. Overall, the data indicate that depending on the nutritional status of ewe, pregnancy alters gene expression of metabolic pathways related to energy generation in the uterus. An impairment in nutrient transport and metabolism in the uterus of pregnant undernourished ewes may explain the greater embryo mortality associated with undernutrition.
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Affiliation(s)
- Victoria de Brun
- Laboratorio de Endocrinología y Metabolismo Animal, Universidad de la República, Montevideo, Uruguay.
| | - Juan J Loor
- Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, United States
| | - Hugo Naya
- Departamento de Bioinformática, Institut Pasteur de Montevideo, Uruguay
| | - Mario Vailati-Riboni
- Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, United States
| | - Omar Bulgari
- Department of Molecular and Translational Medicine, University of Brescia, Italy
| | - Khuram Shahzad
- Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, United States
| | - José Alfonso Abecia
- Instituto de Investigación en Ciencias Ambientales de Aragón (IUCA), Universidad de Zaragoza, Spain
| | | | - Ana Meikle
- Laboratorio de Endocrinología y Metabolismo Animal, Universidad de la República, Montevideo, Uruguay
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9
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Hickman TWP, Baud D, Benhamou L, Hailes HC, Ward JM. Characterisation of four hotdog-fold thioesterases for their implementation in a novel organic acid production system. Appl Microbiol Biotechnol 2020; 104:4397-4406. [PMID: 32193574 PMCID: PMC7190597 DOI: 10.1007/s00253-020-10519-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 02/23/2020] [Accepted: 03/03/2020] [Indexed: 11/24/2022]
Abstract
With increasing interest in the diverse properties of organic acids and their application in synthetic pathways, developing biological tools for producing known and novel organic acids would be very valuable. In such a system, organic acids may be activated as coenzyme A (CoA) esters, then modified by CoA-dependent enzymes, followed by CoA liberation by a broad-acting thioesterase. This study has focused on the identification of suitable thioesterases (TE) for utilisation in such a pathway. Four recombinant hotdog-fold TEs were screened with a range of CoA esters in order to identify a highly active, broad spectrum TE. The TesB-like TE, RpaL, from Rhodopseudomonas palustris was found to be able to use aromatic, alicyclic and both long and short aliphatic CoA esters. Size exclusion chromatography, revealed RpaL to be a monomer of fused hotdog domains, in contrast to the complex quaternary structures found with similar TesB-like TEs. Nonetheless, sequence alignments showed a conserved catalytic triad despite the variation in quaternary arrangement. Kinetic analysis revealed a preference towards short-branched chain CoA esters with the highest specificity towards DL-β-hydroxybutyryl CoA (1.6 × 104 M−1 s−1), which was found to decrease as the acyl chain became longer and more functionalised. Substrate inhibition was observed with the fatty acyl n-heptadecanoyl CoA at concentrations exceeding 0.3 mM; however, this was attributed to its micellar aggregation properties. As a result of the broad activity observed with RpaL, it is a strong candidate for implementation in CoA ester pathways to generate modified or novel organic acids.
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Affiliation(s)
- T W P Hickman
- Department of Biochemical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - D Baud
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - L Benhamou
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - H C Hailes
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - J M Ward
- Department of Biochemical Engineering, University College London, Gower Street, London, WC1E 6BT, UK.
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10
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Khandokar Y, Srivastava P, Raidal S, Sarker S, Forwood JK. Structural basis for disulphide-CoA inhibition of a butyryl-CoA hexameric thioesterase. J Struct Biol 2020; 210:107477. [PMID: 32027968 DOI: 10.1016/j.jsb.2020.107477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/30/2020] [Accepted: 02/02/2020] [Indexed: 10/25/2022]
Abstract
Acyl-coenzyme A thioesterases (ACTs) catalyse the hydrolysis of thioester bonds between fatty-acyl chains and coenzyme A (CoA), producing a free fatty-acyl chain and CoA. These enzymes are expressed ubiquitously across prokaryotes and eukaryotes, and play important roles in lipid metabolism. There are 25 thioesterase families, subdivided based on their active site configuration, protein oligomerization, and substrate specificity. Understanding the mechanism of regulation within these families is important due to their roles in controlling the cell concentration of a range of fatty acids and CoA-bound compounds. Here we report a structural basis for a novel mode of inhibition of an ACT from Staphylococcus aureus. The enzyme displays a hotdog fold composed of five β-strands wrapping around a central α-helix, and an additional 30 residue α-helix located at its C-terminus. We show that the enzyme is a hexamer and has specificity towards butyryl-CoA. Structural analysis revealed putative catalytic residues, and we show through site directed mutagenesis that Asn28, Asp43, and Thr60 are critical for activity. Additionally, we show that the Asn28Ala destabilises the enzyme oligomeric state into two distinct populations. Co-crystallization of the enzyme with the substrate butyryl-CoA produced a crystal with three CoA ligands bound in the enzyme active sites: CoA, butyryl-CoA, and disulphide-CoA, the latter of which inhibits enzyme activity. Our study provides new insights into the structure and specificity of hexameric thioesterases, inhibitory feedback mechanisms, and possible biotechnological applications in short-chain fatty acid production such as biofuels, pharmaceuticals, and industrial compounds.
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Affiliation(s)
- Yogesh Khandokar
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, 3052 Australia; School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Parul Srivastava
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Shane Raidal
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Subir Sarker
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Bundoora, VIC 3086, Australia
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
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11
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Bekeova C, Anderson-Pullinger L, Boye K, Boos F, Sharpadskaya Y, Herrmann JM, Seifert EL. Multiple mitochondrial thioesterases have distinct tissue and substrate specificity and CoA regulation, suggesting unique functional roles. J Biol Chem 2019; 294:19034-19047. [PMID: 31676684 PMCID: PMC6916504 DOI: 10.1074/jbc.ra119.010901] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/16/2019] [Indexed: 12/13/2022] Open
Abstract
Acyl-CoA thioesterases (Acots) hydrolyze fatty acyl-CoA esters. Acots in the mitochondrial matrix are poised to mitigate β-oxidation overload and maintain CoA availability. Several Acots associate with mitochondria, but whether they all localize to the matrix, are redundant, or have different roles is unresolved. Here, we compared the suborganellar localization, activity, expression, and regulation among mitochondrial Acots (Acot2, -7, -9, and -13) in mitochondria from multiple mouse tissues and from a model of Acot2 depletion. Acot7, -9, and -13 localized to the matrix, joining Acot2 that was previously shown to localize there. Mitochondria from heart, skeletal muscle, brown adipose tissue, and kidney robustly expressed Acot2, -9, and -13; Acot9 levels were substantially higher in brown adipose tissue and kidney mitochondria, as was activity for C4:0-CoA, a unique Acot9 substrate. In all tissues, Acot2 accounted for about half of the thioesterase activity for C14:0-CoA and C16:0-CoA. In contrast, liver mitochondria from fed and fasted mice expressed little Acot activity, which was confined to long-chain CoAs and due mainly to Acot7 and Acot13 activities. Matrix Acots occupied different functional niches, based on substrate specificity (Acot9 versus Acot2 and -13) and strong CoA inhibition (Acot7, -9, and -13, but not Acot2). Interpreted in the context of β-oxidation, CoA inhibition would prevent Acot-mediated suppression of β-oxidation, while providing a release valve when CoA is limiting. In contrast, CoA-insensitive Acot2 could provide a constitutive siphon for long-chain fatty acyl-CoAs. These results reveal how the family of matrix Acots can mitigate β-oxidation overload and prevent CoA limitation.
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Affiliation(s)
- Carmen Bekeova
- MitoCare Center, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Lauren Anderson-Pullinger
- MitoCare Center, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Kevin Boye
- MitoCare Center, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Felix Boos
- Division of Cellular Biology, Department of Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Yana Sharpadskaya
- MitoCare Center, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Johannes M Herrmann
- Division of Cellular Biology, Department of Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Erin L Seifert
- MitoCare Center, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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12
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Alves-Bezerra M, Li Y, Acuña M, Ivanova AA, Corey KE, Ortlund EA, Cohen DE. Thioesterase Superfamily Member 2 Promotes Hepatic VLDL Secretion by Channeling Fatty Acids Into Triglyceride Biosynthesis. Hepatology 2019; 70:496-510. [PMID: 30516845 PMCID: PMC6551314 DOI: 10.1002/hep.30411] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 11/30/2018] [Indexed: 12/18/2022]
Abstract
In nonalcoholic fatty liver disease (NAFLD), triglycerides accumulate within the liver because the rates of fatty acid accrual by uptake from plasma and de novo synthesis exceed elimination by mitochondrial oxidation and secretion as very low-density lipoprotein (VLDL) triglycerides. Thioesterase superfamily member 2 (Them2) is an acyl-coenzyme A (CoA) thioesterase that catalyzes the hydrolysis of fatty acyl-CoAs into free fatty acids plus CoASH. Them2 is highly expressed in the liver, as well as other oxidative tissues. Mice globally lacking Them2 are resistant to diet-induced obesity and hepatic steatosis, and exhibit improved glucose homeostasis. These phenotypes are attributable, at least in part, to roles of Them2 in the suppression of thermogenesis in brown adipose tissue and insulin signaling in skeletal muscle. To elucidate the hepatic function of Them2, we created mice with liver-specific deletion of Them2 (L-Them2-/- ). Although L-Them2-/- mice were not protected against excess weight gain, hepatic steatosis or glucose intolerance, they exhibited marked decreases in plasma triglyceride and apolipoprotein B100 concentrations. These were attributable to reduced rates of VLDL secretion owing to decreased incorporation of plasma-derived fatty acids into triglycerides. The absence of hepatic steatosis in L-Them2-/- mice fed chow was explained by compensatory increases in rates of fatty acid oxidation and by decreased de novo lipogenesis in high fat-fed mice. Consistent with a role for Them2 in hepatic VLDL secretion, THEM2 levels were increased in livers of obese patients with NAFLD characterized by simple steatosis. Conclusion: Them2 functions in the liver to direct fatty acids toward triglyceride synthesis for incorporation into VLDL particles. When taken together with its functions in brown adipose and muscle, these findings suggest that Them2 is a target for the management of NAFLD and dyslipidemia.
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Affiliation(s)
- Michele Alves-Bezerra
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021, USA
| | - Yingxia Li
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021, USA
| | - Mariana Acuña
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021, USA
| | - Anna A. Ivanova
- Emory Integrated Lipidomics Core, Emory University, Atlanta, GA 30322, USA
| | - Kathleen E. Corey
- Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA, 02114, USA,Harvard Medical School, Boston, MA 02115, USA
| | - Eric A. Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David E. Cohen
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021, USA,Corresponding author at: Weill Cornell Medical College, Belfer Research Building, 413 E. 69 Street, room 630, New York, NY 10021, USA. Tel.: +1 (646) 962 7681; Fax: +1 (646) 962 0427;
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13
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Tillander V, Miniami A, Alves-Bezerra M, Coleman RA, Cohen DE. Thioesterase superfamily member 2 promotes hepatic insulin resistance in the setting of glycerol-3-phosphate acyltransferase 1-induced steatosis. J Biol Chem 2018; 294:2009-2020. [PMID: 30523156 DOI: 10.1074/jbc.ra118.005184] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 11/21/2018] [Indexed: 02/05/2023] Open
Abstract
Hepatic insulin resistance in the setting of steatosis is attributable at least in part to the accumulation of bioactive lipids that suppress insulin signaling. The mitochondria-associated glycerol-3-phosphate acyltransferase 1 (GPAT1) catalyzes the first committed step in glycerolipid synthesis, and its activity diverts fatty acids from mitochondrial β-oxidation. GPAT1 overexpression in mouse liver leads to hepatic steatosis even in the absence of overnutrition. The mice develop insulin resistance owing to the generation of saturated diacylglycerol and phosphatidic acid molecular species that reduce insulin signaling by activating PKCϵ and by suppressing mTORC2, respectively. Them2, a mitochondria-associated acyl-CoA thioesterase, also participates in the trafficking of fatty acids into oxidative versus glycerolipid biosynthetic pathways. Them2 -/- mice are protected against diet-induced hepatic steatosis and insulin resistance. To determine whether Them2 contributes to hepatic insulin resistance due to hepatic overexpression of GPAT1, recombinant adenovirus was used to overexpress GPAT1 in livers of chow-fed Them2 +/+ and Them2 -/- mice. Hepatic GPAT1 overexpression led to steatosis in both genotypes. In the setting of GPAT1 overexpression, glucose tolerance was reduced in Them2 +/+ but not Them2 -/- mice, without influencing whole-body insulin sensitivity or basal hepatic glucose production. Improved glucose tolerance in Them2 -/- mice was associated with reduced PKCϵ translocation. Preserved insulin receptor activity was supported by Thr-308 phosphorylation of Akt following GPAT1 overexpression in Them2 -/- hepatocytes. These findings suggest a pathogenic role of Them2 in the biosynthesis of glycerolipid metabolites that promote hepatic insulin resistance.
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Affiliation(s)
- Veronika Tillander
- From the Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, New York 10021.,the Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institute, 14152 Huddinge, Sweden
| | - Akihiro Miniami
- From the Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, New York 10021.,the Department of Gastroenterology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan, and
| | - Michele Alves-Bezerra
- From the Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, New York 10021
| | - Rosalind A Coleman
- the Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina 27599
| | - David E Cohen
- From the Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, New York 10021,
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14
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Caldo KMP, Shen W, Xu Y, Hanley-Bowdoin L, Chen G, Weselake RJ, Lemieux MJ. Diacylglycerol acyltransferase 1 is activated by phosphatidate and inhibited by SnRK1-catalyzed phosphorylation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 96:287-299. [PMID: 30003607 DOI: 10.1111/tpj.14029] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/23/2018] [Accepted: 06/26/2018] [Indexed: 05/06/2023]
Abstract
Diacylglycerol acyltransferase 1 (DGAT1) catalyzes the final and committed step in the Kennedy pathway for triacylglycerol (TAG) biosynthesis and, as such, elucidating its mode of regulation is critical to understand the fundamental aspects of carbon metabolism in oleaginous crops. In this study, purified Brassica napus diacylglycerol acyltransferase 1 (BnaDGAT1) in n-dodecyl-β-d-maltopyranoside micelles was lipidated to form mixed micelles and subjected to detailed biochemical analysis. The degree of mixed micelle fluidity appeared to influence acyltransferase activity. BnaDGAT1 exhibited a sigmoidal response and eventual substrate inhibition with respect to increasing concentrations of oleoyl-CoA. Phosphatidate (PA) was identified as a feed-forward activator of BnaDGAT1, enabling the final enzyme in the Kennedy pathway to adjust to the incoming flow of carbon leading to TAG. In the presence of PA, the oleoyl-CoA saturation plot became more hyperbolic and desensitized to substrate inhibition indicating that PA facilitates the transition of the enzyme into the more active state. PA may also relieve possible autoinhibition of BnaDGAT1 brought about by the N-terminal regulatory domain, which was shown to interact with PA. Indeed, PA is a key effector modulating lipid homeostasis, in addition to its well recognized role in lipid signaling. BnaDGAT1 was also shown to be a substrate of the sucrose non-fermenting-1-related kinase 1 (SnRK1), which catalyzed phosphorylation of the enzyme and converted it to a less active form. Thus, this known regulator of carbon metabolism directly influences TAG biosynthesis.
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Affiliation(s)
- Kristian Mark P Caldo
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Wei Shen
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Yang Xu
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Linda Hanley-Bowdoin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Randall J Weselake
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
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15
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Steensels S, Ersoy BA. Fatty acid activation in thermogenic adipose tissue. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:79-90. [PMID: 29793055 DOI: 10.1016/j.bbalip.2018.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 03/10/2018] [Accepted: 05/17/2018] [Indexed: 02/07/2023]
Abstract
Channeling carbohydrates and fatty acids to thermogenic tissues, including brown and beige adipocytes, have garnered interest as an approach for the management of obesity-related metabolic disorders. Mitochondrial fatty acid oxidation (β-oxidation) is crucial for the maintenance of thermogenesis. Upon cellular fatty acid uptake or following lipolysis from triglycerides (TG), fatty acids are esterified to coenzyme A (CoA) to form active acyl-CoA molecules. This enzymatic reaction is essential for their utilization in β-oxidation and thermogenesis. The activation and deactivation of fatty acids are regulated by two sets of enzymes called acyl-CoA synthetases (ACS) and acyl-CoA thioesterases (ACOT), respectively. The expression levels of ACS and ACOT family members in thermogenic tissues will determine the substrate availability for β-oxidation, and consequently the thermogenic capacity. Although the role of the majority of ACS and ACOT family members in thermogenesis remains unclear, recent proceedings link the enzymatic activities of ACS and ACOT family members to metabolic disorders and thermogenesis. Elucidating the contributions of specific ACS and ACOT family members to trafficking of fatty acids towards thermogenesis may reveal novel targets for modulating thermogenic capacity and treating metabolic disorders.
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Affiliation(s)
- Sandra Steensels
- Department of Medicine, Division of Gastroenterology and Hepatology, Weill Cornell Medical College, New York, NY, USA
| | - Baran A Ersoy
- Department of Medicine, Division of Gastroenterology and Hepatology, Weill Cornell Medical College, New York, NY, USA.
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16
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Desai A, Alves-Bezerra M, Li Y, Ozdemir C, Bare CJ, Li Y, Hagen SJ, Cohen DE. Regulation of fatty acid trafficking in liver by thioesterase superfamily member 1. J Lipid Res 2018; 59:368-379. [PMID: 29208699 PMCID: PMC5794430 DOI: 10.1194/jlr.m081455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/04/2017] [Indexed: 12/13/2022] Open
Abstract
Thioesterase superfamily member 1 (Them1) is an acyl-CoA thioesterase that is highly expressed in brown adipose tissue, where it functions to suppress energy expenditure. Lower Them1 expression levels in the liver are upregulated in response to high-fat feeding. Them1-/- mice are resistant to diet-induced obesity, hepatic steatosis, and glucose intolerance, but the contribution of Them1 in liver is unclear. To examine its liver-specific functions, we created conditional transgenic mice, which, when bred to Them1-/- mice and activated, expressed Them1 exclusively in the liver. Mice with liver-specific Them1 expression exhibited no changes in energy expenditure. Rates of fatty acid oxidation were increased, whereas hepatic VLDL triglyceride secretion rates were decreased by hepatic Them1 expression. When fed a high-fat diet, Them1 expression in liver promoted excess steatosis in the setting of reduced rates of fatty acid oxidation and preserved glycerolipid synthesis. Liver-specific Them1 expression did not influence glucose tolerance or insulin sensitivity, but did promote hepatic gluconeogenesis in high-fat-fed animals. This was attributable to the generation of excess fatty acids, which activated PPARα and promoted expression of gluconeogenic genes. These findings reveal a regulatory role for Them1 in hepatocellular fatty acid trafficking.
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Affiliation(s)
- Anal Desai
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
| | - Michele Alves-Bezerra
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
| | - Yingxia Li
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
| | - Cafer Ozdemir
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118
| | - Curtis J Bare
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
| | - Yue Li
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215
| | - Susan J Hagen
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215
| | - David E Cohen
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
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17
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Ersoy BA, Maner-Smith KM, Li Y, Alpertunga I, Cohen DE. Thioesterase-mediated control of cellular calcium homeostasis enables hepatic ER stress. J Clin Invest 2017; 128:141-156. [PMID: 29202465 DOI: 10.1172/jci93123] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 10/12/2017] [Indexed: 12/11/2022] Open
Abstract
The incorporation of excess saturated free fatty acids (SFAs) into membrane phospholipids within the ER promotes ER stress, insulin resistance, and hepatic gluconeogenesis. Thioesterase superfamily member 2 (Them2) is a mitochondria-associated long-chain fatty acyl-CoA thioesterase that is activated upon binding phosphatidylcholine transfer protein (PC-TP). Under fasting conditions, the Them2/PC-TP complex directs saturated fatty acyl-CoA toward β-oxidation. Here, we showed that during either chronic overnutrition or acute induction of ER stress, Them2 and PC-TP play critical roles in trafficking SFAs into the glycerolipid biosynthetic pathway to form saturated phospholipids, which ultimately reduce ER membrane fluidity. The Them2/PC-TP complex activated ER stress pathways by enhancing translocon-mediated efflux of ER calcium. The increased cytosolic calcium, in turn, led to the phosphorylation of calcium/calmodulin-dependent protein kinase II, which promoted both hepatic insulin resistance and gluconeogenesis. These findings delineate a mechanistic link between obesity and insulin resistance and establish the Them2/PC-TP complex as an attractive target for the management of hepatic steatosis and insulin resistance.
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18
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Hung JY, Chiang SR, Liu KT, Tsai MJ, Huang MS, Shieh JM, Yen MC, Hsu YL. Overexpression and proliferation dependence of acyl-CoA thioesterase 11 and 13 in lung adenocarcinoma. Oncol Lett 2017; 14:3647-3656. [PMID: 28927126 DOI: 10.3892/ol.2017.6594] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 05/08/2017] [Indexed: 11/06/2022] Open
Abstract
The metabolites of fatty acyl-Coenzyme A (CoA) and metabolic enzymes contribute to lipid biosynthesis, signal transduction, and gene transcription. Previous studies have indicated that elevated concentrations of specific free fatty acids in the plasma and overexpression of specific fatty acyl-CoA metabolic enzymes are observed in patients with lung adenocarcinoma. However, there are >30 enzymes in this metabolic network and have been fully investigated. In the present study, the expression levels of enzymes in the acyl-CoA synthetase (ACS) and acyl-CoA thioesterase (ACOT) families were analyzed from six microarray expression datasets that were collected from Gene Expression Omnibus. Compared with adjacent non-tumor lung tissue, lung adenocarcinoma tissue exhibited significantly higher ACOT11 and ACOT13 expression. Kaplan-Meier plotter database analysis demonstrated that high levels of ACOT11 and ACOT13 were associated with a worse overall survival rate. The proliferation of the lung adenocarcinoma cell lines CL1-0 and CL1-5 was inhibited when ACOT11 and ACOT13 were downregulated by short hairpin RNA. Although ACOT11 and ACOT13 knockdown did not significantly affect the total amount of intracellular and medium-free fatty acids, ACOT11 and ACOT13 knockdown-mediated growth inhibition was rescued by the addition of fatty acids. In conclusion, ACOT11 and ACOT13 were upregulated in clinical specimens of lung adenocarcinoma, which may contribute to increased cell proliferation through the increased availability of fatty acids. The metabolites of the two enzymes may be critical for development of lung adenocarcinoma.
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Affiliation(s)
- Jen-Yu Hung
- School of Medicine, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C.,Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C
| | - Shyh-Ren Chiang
- Department of Internal Medicine, Chi Mei Medical Center, Tainan 710, Taiwan, R.O.C
| | - Kuan-Ting Liu
- School of Medicine, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C.,Department of Emergency Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C.,Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan, R.O.C
| | - Ming-Ju Tsai
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C
| | - Ming-Shyan Huang
- School of Medicine, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C.,Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C
| | - Jiunn-Min Shieh
- Department of Internal Medicine, Chi Mei Medical Center, Tainan 710, Taiwan, R.O.C
| | - Meng-Chi Yen
- Department of Emergency Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan, R.O.C
| | - Ya-Ling Hsu
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan, R.O.C
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19
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Tillander V, Alexson SEH, Cohen DE. Deactivating Fatty Acids: Acyl-CoA Thioesterase-Mediated Control of Lipid Metabolism. Trends Endocrinol Metab 2017; 28:473-484. [PMID: 28385385 PMCID: PMC5474144 DOI: 10.1016/j.tem.2017.03.001] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 03/01/2017] [Indexed: 12/28/2022]
Abstract
The cellular uptake of free fatty acids (FFA) is followed by esterification to coenzyme A (CoA), generating fatty acyl-CoAs that are substrates for oxidation or incorporation into complex lipids. Acyl-CoA thioesterases (ACOTs) constitute a family of enzymes that hydrolyze fatty acyl-CoAs to form FFA and CoA. Although biochemically and biophysically well characterized, the metabolic functions of these enzymes remain incompletely understood. Existing evidence suggests regulatory roles in controlling rates of peroxisomal and mitochondrial fatty acyl-CoA oxidation, as well as in the subcellular trafficking of fatty acids. Emerging data implicate ACOTs in the pathogenesis of metabolic diseases, suggesting that better understanding their pathobiology could reveal unique targets in the management of obesity, diabetes, and nonalcoholic fatty liver disease.
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Affiliation(s)
- Veronika Tillander
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, 14186, Sweden
| | - Stefan E H Alexson
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, 14186, Sweden
| | - David E Cohen
- Division of Gastroenterology and Hepatology, Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021, USA.
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20
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Krisko TI, LeClair KB, Cohen DE. Genetic ablation of phosphatidylcholine transfer protein/StarD2 in ob/ob mice improves glucose tolerance without increasing energy expenditure. Metabolism 2017; 68:145-149. [PMID: 28183446 PMCID: PMC5308448 DOI: 10.1016/j.metabol.2016.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 10/24/2016] [Accepted: 11/22/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Phosphatidylcholine transfer protein (PC-TP; synonym StarD2) is highly expressed in liver and oxidative tissues. PC-TP promotes hepatic glucose production during fasting and aggravates glucose intolerance in high fat fed mice. However, because PC-TP also suppresses thermogenesis in brown adipose tissue (BAT), its direct contribution to obesity-associated diabetes in mice remains unclear. Here we examined the effects of genetic PC-TP ablation on glucose homeostasis in leptin-deficient ob/ob mice, which exhibit both diabetes and altered thermoregulation. ANIMALS/METHODS Mice lacking both PC-TP and leptin (Pctp-/-;ob/ob) were prepared by crossing Pctp-/- with ob/+ mice. Glucose homeostasis was assessed by standard assays, and energy expenditure was determined by indirect calorimetry using a comprehensive laboratory animal monitoring system, which also recorded physical activity and food intake. Body composition was determined by NMR and hepatic lipids by enzymatic assays. Core body temperature was measured using a rectal thermocouple probe. RESULTS Pctp-/-;ob/ob mice demonstrated improved glucose homeostasis, as evidenced by markedly improved glucose and pyruvate tolerance tests, without changes in insulin tolerance. However, there were no differences in EE at any ambient temperature. There were also no effects of PC-TP expression on physical activity, food intake or core body temperature. CONCLUSIONS Improved glucose tolerance in Pctp-/-;ob/ob mice in the absence of increases in energy expenditure or core body temperature indicates a direct pathogenic role for PC-TP in diabetes in leptin deficient mice.
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Affiliation(s)
- Tibor I Krisko
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
| | - Katherine B LeClair
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
| | - David E Cohen
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA.
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21
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Thornton KJ, Chapalamadugu KC, Eldredge EM, Murdoch GK. Analysis of Longissimus thoracis Protein Expression Associated with Variation in Carcass Quality Grade and Marbling of Beef Cattle Raised in the Pacific Northwestern United States. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:1434-1442. [PMID: 28117999 DOI: 10.1021/acs.jafc.6b02795] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Longissimus thoracis (LD) samples from 500 cattle were screened for protein expression differences relative to carcass quality grade. The LD of the top 5% (low prime and high choice, HQ) and bottom 5% (low select, LQ) carcasses were analyzed using two-dimensional difference gel electrophoresis and Western blot. Following initial screening, 11 candidate proteins were selected for Western blot analyses. Differentially expressed proteins were clustered into four groups: (1) heat shock proteins and oxidative protection, (2) sarcomeric proteins (muscle maturity and fiber type), (3) metabolism and energetics, and (4) miscellaneous proteins. Proteins from groups 1 and 2 were greater in HQ carcasses. Alternatively, increased quantities of proteins from group 3 were observed in LQ carcasses. Proteomic differences provide insights into pathways contributing to carcass quality grade. A deeper understanding of the physiological pathways involved in carcass quality grade development may allow producers to employ production practices that improve quality grade.
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Affiliation(s)
- Kara J Thornton
- Department of Animal and Veterinary Sciences. University of Idaho , 606 Rayburn Street Moscow, Idaho 83844-2330, United States
| | - Kalyan C Chapalamadugu
- Department of Animal and Veterinary Sciences. University of Idaho , 606 Rayburn Street Moscow, Idaho 83844-2330, United States
| | - Eric M Eldredge
- Department of Animal and Veterinary Sciences. University of Idaho , 606 Rayburn Street Moscow, Idaho 83844-2330, United States
| | - Gordon K Murdoch
- Department of Animal and Veterinary Sciences. University of Idaho , 606 Rayburn Street Moscow, Idaho 83844-2330, United States
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22
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Chen B, Du Q, Chen J, Yang X, Tian J, Li B, Zhang D. Dissection of allelic interactions among Pto-miR257 and its targets and their effects on growth and wood properties in Populus. Heredity (Edinb) 2016; 117:73-83. [PMID: 27118153 DOI: 10.1038/hdy.2016.26] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/02/2016] [Indexed: 11/09/2022] Open
Abstract
MicroRNAs (miRNAs) have important roles in the regulation of genes; however, for trees few studies have explored the potential impact of the interactions between miRNAs and their target genes. Here, we performed transcript profiling and association genetics (single-SNP, haplotype-based and multi-SNP associations) to study the genetic regulatory relationship of Pto-miR257 and its 12 target genes in 435 individuals of a natural population of Populus tomentosa. Expression profiling of Pto-miR257 and its targets showed a negative relationship between their expression levels. Of the 61 single-nucleotide polymorphisms (SNPs) detected in Pto-miR257, 6 in the pre-mature region strongly affected its secondary stability and 1 in the mature region could alter its target spectrum. Among the 1029 SNPs in the targets, 3 were located in target sites that could change the binding affinity of Pto-miR257. Single-SNP association analysis revealed that SNPs in Pto-miR257 and target genes associated with both growth and wood property traits, in agreement with haplotype-based identifications. Multi-SNP association found that 10 targets shared at least one common trait with Pto-miR257, with phenotypic variance from 0.5 to 8.5%, suggesting a possible internal genetic interaction between them. Epistasis analysis showed significant epistatic interactions among Pto-miR257 and its targets. Therefore, our study demonstrated Pto-miR257 and its 12 targets had roles in wood formation and revealed the genetic interaction network between the miRNA and its targets under additive, dominant and epistatic models. Thus, association genetics can be used to decipher the interactions between miRNAs and their target genes and to help understand the genetic architecture of complex traits.
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Affiliation(s)
- B Chen
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China.,Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China
| | - Q Du
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China.,Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China
| | - J Chen
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China.,Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China
| | - X Yang
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China.,Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China
| | - J Tian
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China.,Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China
| | - B Li
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China.,Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China.,Department of Forestry, North Carolina State University, Raleigh, NC, USA
| | - D Zhang
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China.,Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, People's Republic of China
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23
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Khandokar YB, Srivastava P, Sarker S, Swarbrick CMD, Aragao D, Cowieson N, Forwood JK. Structural and Functional Characterization of the PaaI Thioesterase from Streptococcus pneumoniae Reveals a Dual Specificity for Phenylacetyl-CoA and Medium-chain Fatty Acyl-CoAs and a Novel CoA-induced Fit Mechanism. J Biol Chem 2015; 291:1866-1876. [PMID: 26538563 DOI: 10.1074/jbc.m115.677484] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Indexed: 11/06/2022] Open
Abstract
PaaI thioesterases are members of the TE13 thioesterase family that catalyze the hydrolysis of thioester bonds between coenzyme A and phenylacetyl-CoA. In this study we characterize the PaaI thioesterase from Streptococcus pneumoniae (SpPaaI), including structural analysis based on crystal diffraction data to 1.8-Å resolution, to reveal two double hotdog domains arranged in a back to back configuration. Consistent with the crystallography data, both size exclusion chromatography and small angle x-ray scattering data support a tetrameric arrangement of thioesterase domains in solution. Assessment of SpPaaI activity against a range of acyl-CoA substrates showed activity for both phenylacetyl-CoA and medium-chain fatty-acyl CoA substrates. Mutagenesis of putative active site residues reveals Asn(37), Asp(52), and Thr(68) are important for catalysis, and size exclusion chromatography analysis and x-ray crystallography confirm that these mutants retain the same tertiary and quaternary structures, establishing that the reduced activity is not a result of structural perturbations. Interestingly, the structure of SpPaaI in the presence of CoA provides a structural basis for the observed substrate specificity, accommodating a 10-carbon fatty acid chain, and a large conformational change of up to 38 Å in the N terminus, and a loop region involving Tyr(38)-Tyr(39). This is the first time PaaI thioesterases have displayed a dual specificity for medium-chain acyl-CoAs substrates and phenylacetyl-CoA substrates, and we provide a structural basis for this specificity, highlighting a novel induced fit mechanism that is likely to be conserved within members of this enzyme family.
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Affiliation(s)
| | | | - Subir Sarker
- School of Animal and Veterinary Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, New South Wales 2678 and
| | | | - David Aragao
- the Australian Synchrotron, Blackburn Rd., Clayton, Victoria 3168, Australia
| | - Nathan Cowieson
- the Australian Synchrotron, Blackburn Rd., Clayton, Victoria 3168, Australia
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24
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Bavdek A, Vazquez HM, Conzelmann A. Enzyme-coupled assays for flip-flop of acyl-Coenzyme A in liposomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2960-6. [PMID: 26325346 DOI: 10.1016/j.bbamem.2015.08.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/15/2015] [Accepted: 08/27/2015] [Indexed: 10/23/2022]
Abstract
Acyl-Coenzyme A is made in the cytosol. Certain enzymes using acyl-CoA seem to operate in the lumen of the ER but no corresponding flippases for acyl-CoA or an activated acyl have been described. In order to test the ability of purified candidate flippases to operate the transport of acyl-CoA through lipid bilayers in vitro we developed three enzyme-coupled assays using large unilamellar vesicles (LUVs) obtained by detergent removal. The first assay uses liposomes encapsulating a water-soluble acyl-CoA:glycerol-3-phosphate acyl transferase plus glycerol-3-phosphate (G3P). It measures formation of [(3)H]lyso-phosphatidic acid inside liposomes after [(3)H]palmitoyl-CoA has been added from outside. Two other tests use empty liposomes containing [(3)H]palmitoyl-CoA in the inner membrane leaflet, to which either soluble acyl-CoA:glycerol-3-phosphate acyl transferase plus glycerol-3-phosphate or alkaline phosphatase are added from outside. Here one can follow the appearance of [(3)H]lyso-phosphatidic acid or of dephosphorylated [(3)H]acyl-CoA, respectively, both being made outside the liposomes. Although the liposomes may retain small amounts of detergent, all these tests show that palmitoyl-CoA crosses the lipid bilayer only very slowly and that the lipid composition of liposomes barely affects the flip-flop rate. Thus, palmitoyl-CoA cannot cross the membrane spontaneously implying that in vivo some transport mechanism is required.
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Affiliation(s)
- Andrej Bavdek
- Division of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg, CH-1700, Switzerland
| | - Hector M Vazquez
- Division of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg, CH-1700, Switzerland
| | - Andreas Conzelmann
- Division of Biochemistry, Department of Biology, University of Fribourg, Chemin du Musée 10, Fribourg, CH-1700, Switzerland.
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25
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Yu S, Li H, Gao F, Zhou Y. Crystal structure and potential physiological role of zebra fish thioesterase superfamily member 2 (fTHEM2). Biochem Biophys Res Commun 2015; 463:912-6. [PMID: 26067557 DOI: 10.1016/j.bbrc.2015.06.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 06/05/2015] [Indexed: 11/28/2022]
Abstract
Thioesterase superfamily member 2 (THEM2) is an essential protein for mammalian cell proliferation. It belongs to the hotdog-fold thioesterase superfamily and catalyzes hydrolysis of thioester bonds of acyl-CoA in vitro, while its in vivo function remains unrevealed. In this study, Zebra fish was selected as a model organism to facilitate the investigations on THEM2. First, we solved the crystal structure of recombinant fTHEM2 at the resolution of 1.80 Å, which displayed a similar scaffolding as hTHEM2. Second, functional studies demonstrated that fTHEM2 is capable of hydrolyzing palmitoyl-CoA in vitro. In addition, injection of morpholino against fTHEM2 at one-cell stage resulted in distorted early embryo development, including delayed cell division, retarded development and increased death rate. The above findings validated our hypothesis that fTHEM2 could serve as an ideal surrogate for studying the physiological functions of THEM2.
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Affiliation(s)
- Shanshan Yu
- Non-coding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, PR China
| | - Han Li
- Non-coding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, PR China
| | - Feng Gao
- Non-coding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, PR China
| | - Ying Zhou
- Non-coding RNA Laboratory, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, PR China.
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26
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Neess D, Bek S, Engelsby H, Gallego SF, Færgeman NJ. Long-chain acyl-CoA esters in metabolism and signaling: Role of acyl-CoA binding proteins. Prog Lipid Res 2015; 59:1-25. [PMID: 25898985 DOI: 10.1016/j.plipres.2015.04.001] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/11/2015] [Accepted: 04/09/2015] [Indexed: 02/03/2023]
Abstract
Long-chain fatty acyl-CoA esters are key intermediates in numerous lipid metabolic pathways, and recognized as important cellular signaling molecules. The intracellular flux and regulatory properties of acyl-CoA esters have been proposed to be coordinated by acyl-CoA-binding domain containing proteins (ACBDs). The ACBDs, which comprise a highly conserved multigene family of intracellular lipid-binding proteins, are found in all eukaryotes and ubiquitously expressed in all metazoan tissues, with distinct expression patterns for individual ACBDs. The ACBDs are involved in numerous intracellular processes including fatty acid-, glycerolipid- and glycerophospholipid biosynthesis, β-oxidation, cellular differentiation and proliferation as well as in the regulation of numerous enzyme activities. Little is known about the specific roles of the ACBDs in the regulation of these processes, however, recent studies have gained further insights into their in vivo functions and provided further evidence for ACBD-specific functions in cellular signaling and lipid metabolic pathways. This review summarizes the structural and functional properties of the various ACBDs, with special emphasis on the function of ACBD1, commonly known as ACBP.
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Affiliation(s)
- Ditte Neess
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Signe Bek
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Hanne Engelsby
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Sandra F Gallego
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Nils J Færgeman
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark.
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27
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Generous A, Thorson M, Barcus J, Jacher J, Busch M, Sleister H. Identification of putative interactions between swine and human influenza A virus nucleoprotein and human host proteins. Virol J 2014; 11:228. [PMID: 25547032 PMCID: PMC4297426 DOI: 10.1186/s12985-014-0228-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 12/15/2014] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Influenza A viruses (IAVs) are important pathogens that affect the health of humans and many additional animal species. IAVs are enveloped, negative single-stranded RNA viruses whose genome encodes at least ten proteins. The IAV nucleoprotein (NP) is a structural protein that associates with the viral RNA and is essential for virus replication. Understanding how IAVs interact with host proteins is essential for elucidating all of the required processes for viral replication, restrictions in species host range, and potential targets for antiviral therapies. METHODS In this study, the NP from a swine IAV was cloned into a yeast two-hybrid "bait" vector for expression of a yeast Gal4 binding domain (BD)-NP fusion protein. This "bait" was used to screen a Y2H human HeLa cell "prey" library which consisted of human proteins fused to the Gal4 protein's activation domain (AD). The interaction of "bait" and "prey" proteins resulted in activation of reporter genes. RESULTS Seventeen positive bait-prey interactions were isolated in yeast. All of the "prey" isolated also interact in yeast with a NP "bait" cloned from a human IAV strain. Isolation and sequence analysis of the cDNAs encoding the human prey proteins revealed ten different human proteins. These host proteins are involved in various host cell processes and structures, including purine biosynthesis (PAICS), metabolism (ACOT13), proteasome (PA28B), DNA-binding (MSANTD3), cytoskeleton (CKAP5), potassium channel formation (KCTD9), zinc transporter function (SLC30A9), Na+/K+ ATPase function (ATP1B1), and RNA splicing (TRA2B). CONCLUSIONS Ten human proteins were identified as interacting with IAV NP in a Y2H screen. Some of these human proteins were reported in previous screens aimed at elucidating host proteins relevant to specific viral life cycle processes such as replication. This study extends previous findings by suggesting a mechanism by which these host proteins associate with the IAV, i.e., physical interaction with NP. Furthermore, this study revealed novel host protein-NP interactions in yeast.
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Affiliation(s)
- Alex Generous
- Biology Department, Drake University, 1344 27th St., Des Moines, IA, 50311, USA.
| | - Molly Thorson
- Biology Department, Drake University, 1344 27th St., Des Moines, IA, 50311, USA.
| | - Jeff Barcus
- Biology Department, Drake University, 1344 27th St., Des Moines, IA, 50311, USA.
| | - Joseph Jacher
- Biology Department, Drake University, 1344 27th St., Des Moines, IA, 50311, USA.
| | - Marc Busch
- Biology Department, Drake University, 1344 27th St., Des Moines, IA, 50311, USA.
| | - Heidi Sleister
- Biology Department, Drake University, 1344 27th St., Des Moines, IA, 50311, USA.
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28
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Moffat C, Bhatia L, Nguyen T, Lynch P, Wang M, Wang D, Ilkayeva OR, Han X, Hirschey MD, Claypool SM, Seifert EL. Acyl-CoA thioesterase-2 facilitates mitochondrial fatty acid oxidation in the liver. J Lipid Res 2014; 55:2458-70. [PMID: 25114170 DOI: 10.1194/jlr.m046961] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Acyl-CoA thioesterase (Acot)2 localizes to the mitochondrial matrix and hydrolyses long-chain fatty acyl-CoA into free FA and CoASH. Acot2 is expressed in highly oxi-dative tissues and is poised to modulate mitochondrial FA oxidation (FAO), yet its biological role is unknown. Using a model of adenoviral Acot2 overexpression in mouse liver (Ad-Acot2), we show that Acot2 increases the utilization of FA substrate during the daytime in ad libitum-fed mice, but the nighttime switch to carbohydrate oxidation is similar to control mice. In further support of elevated FAO in Acot2 liver, daytime serum ketones were higher in Ad-Acot2 mice, and overnight fasting led to minimal hepatic steatosis as compared with control mice. In liver mitochondria from Ad-Acot2 mice, phosphorylating O₂ consumption was higher with lipid substrate, but not with nonlipid substrate. This increase depended on whether FA could be activated on the outer mitochondrial membrane, suggesting that the FA released by Acot2 could be effluxed from mitochondria then taken back up again for oxidation. This circuit would prevent the build-up of inhibitory long-chain fatty acyl-CoA esters. Altogether, our findings indicate that Acot2 can enhance FAO, possibly by mitigating the accumulation of FAO intermediates within the mitochondrial matrix.
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Affiliation(s)
- Cynthia Moffat
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Lavesh Bhatia
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Teresa Nguyen
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Peter Lynch
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Miao Wang
- Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, FL 32827
| | - Dongning Wang
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27710
| | - Olga R Ilkayeva
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27710
| | - Xianlin Han
- Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, FL 32827
| | - Matthew D Hirschey
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27710
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins School of Medicine, Baltimore, MD 21205
| | - Erin L Seifert
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107
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29
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Swarbrick CMD, Roman N, Cowieson N, Patterson EI, Nanson J, Siponen MI, Berglund H, Lehtiö L, Forwood JK. Structural basis for regulation of the human acetyl-CoA thioesterase 12 and interactions with the steroidogenic acute regulatory protein-related lipid transfer (START) domain. J Biol Chem 2014; 289:24263-74. [PMID: 25002576 DOI: 10.1074/jbc.m114.589408] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Acetyl-CoA plays a fundamental role in cell signaling and metabolic pathways, with its cellular levels tightly controlled through reciprocal regulation of enzymes that mediate its synthesis and catabolism. ACOT12, the primary acetyl-CoA thioesterase in the liver of human, mouse, and rat, is responsible for cleavage of the thioester bond within acetyl-CoA, producing acetate and coenzyme A for a range of cellular processes. The enzyme is regulated by ADP and ATP, which is believed to be mediated through the ligand-induced oligomerization of the thioesterase domains, whereby ATP induces active dimers and tetramers, whereas apo- and ADP-bound ACOT12 are monomeric and inactive. Here, using a range of structural and biophysical techniques, it is demonstrated that ACOT12 is a trimer rather than a tetramer and that neither ADP nor ATP exert their regulatory effects by altering the oligomeric status of the enzyme. Rather, the binding site and mechanism of ADP regulation have been determined to occur through two novel regulatory regions, one involving a large loop that links the thioesterase domains (Phe(154)-Thr(178)), defined here as RegLoop1, and a second region involving the C terminus of thioesterase domain 2 (Gln(304)-Gly(326)), designated RegLoop2. Mutagenesis confirmed that Arg(312) and Arg(313) are crucial for this mode of regulation, and novel interactions with the START domain are presented together with insights into domain swapping within eukaryotic thioesterases for substrate recognition. In summary, these experiments provide the first structural insights into the regulation of this enzyme family, revealing an alternate hypothesis likely to be conserved throughout evolution.
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Affiliation(s)
- Crystall M D Swarbrick
- From the School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia
| | - Noelia Roman
- From the School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia
| | - Nathan Cowieson
- the Australian Synchrotron, Clayton, Victoria 3168, Australia, and
| | - Edward I Patterson
- From the School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia
| | - Jeffrey Nanson
- From the School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia
| | - Marina I Siponen
- the Department of Medical Biochemistry and Biophysics, Structural Genomics Consortium, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Helena Berglund
- the Department of Medical Biochemistry and Biophysics, Structural Genomics Consortium, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Lari Lehtiö
- the Department of Medical Biochemistry and Biophysics, Structural Genomics Consortium, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Jade K Forwood
- From the School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia,
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30
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Thioesterase superfamily member 2 (Them2) and phosphatidylcholine transfer protein (PC-TP) interact to promote fatty acid oxidation and control glucose utilization. Mol Cell Biol 2014; 34:2396-408. [PMID: 24732803 DOI: 10.1128/mcb.01601-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Thioesterase superfamily member 2 (Them2) is a mitochondrion-associated long-chain fatty acyl coenzyme A (CoA) thioesterase that is highly expressed in the liver and oxidative tissues. Them2 activity in vitro is increased when it interacts with phosphatidylcholine transfer protein (PC-TP), a cytosolic lipid binding protein. Them2-/- and Pctp-/- mice exhibit enhanced hepatic insulin sensitivity and increased adaptive thermogenesis, and Them2-/- mice are also resistant to diet-induced hepatic steatosis. Although we showed previously that a Them2-PC-TP complex suppresses insulin signaling, the enzymatic activity of Them2 suggests additional direct involvement in regulating hepatic nutrient homeostasis. Here we used cultured primary hepatocytes to elucidate biochemical and cellular mechanisms by which Them2 and PC-TP regulate lipid and glucose metabolism. Under conditions simulating fasting, Them2-/- and Pctp-/- hepatocytes each exhibited decreased rates of fatty acid oxidation and gluconeogenesis. In results indicative of Them2-dependent regulation by PC-TP, chemical inhibition of PC-TP failed to reproduce these changes in Them2-/- hepatocytes. In contrast, rates of glucose oxidation and lipogenesis in the presence of high glucose concentrations were decreased only in Them2-/- hepatocytes. These findings reveal a primary role for Them2 in promoting mitochondrial oxidation of fatty acids and glucose in the liver.
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31
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Tillander V, Arvidsson Nordström E, Reilly J, Strozyk M, Van Veldhoven PP, Hunt MC, Alexson SEH. Acyl-CoA thioesterase 9 (ACOT9) in mouse may provide a novel link between fatty acid and amino acid metabolism in mitochondria. Cell Mol Life Sci 2014; 71:933-48. [PMID: 23864032 PMCID: PMC11114068 DOI: 10.1007/s00018-013-1422-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 06/13/2013] [Accepted: 07/04/2013] [Indexed: 02/03/2023]
Abstract
Acyl-CoA thioesterase (ACOT) activities are found in prokaryotes and in several compartments of eukaryotes where they hydrolyze a wide range of acyl-CoA substrates and thereby regulate intracellular acyl-CoA/CoA/fatty acid levels. ACOT9 is a mitochondrial ACOT with homologous genes found from bacteria to humans and in this study we have carried out an in-depth kinetic characterization of ACOT9 to determine its possible physiological function. ACOT9 showed unusual kinetic properties with activity peaks for short-, medium-, and saturated long-chain acyl-CoAs with highest V max with propionyl-CoA and (iso) butyryl-CoA while K cat/K m was highest with saturated long-chain acyl-CoAs. Further characterization of the short-chain acyl-CoA activity revealed that ACOT9 also hydrolyzes a number of short-chain acyl-CoAs and short-chain methyl-branched CoA esters that suggest a role for ACOT9 in regulation also of amino acid metabolism. In spite of markedly different K ms, ACOT9 can hydrolyze both short- and long-chain acyl-CoAs simultaneously, indicating that ACOT9 may provide a novel regulatory link between fatty acid and amino acid metabolism in mitochondria. Based on similar acyl-CoA chain-length specificities of recombinant ACOT9 and ACOT activity in mouse brown adipose tissue and kidney mitochondria, we conclude that ACOT9 is the major mitochondrial ACOT hydrolyzing saturated C2-C20-CoA in these tissues. Finally, ACOT9 activity is strongly regulated by NADH and CoA, suggesting that mitochondrial metabolic state regulates the function of ACOT9.
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Affiliation(s)
- Veronika Tillander
- Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institutet, C1-74, Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Elisabet Arvidsson Nordström
- Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institutet, C1-74, Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Jenny Reilly
- Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institutet, C1-74, Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Malgorzata Strozyk
- Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institutet, C1-74, Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Paul P. Van Veldhoven
- Department of Cellular and Molecular Medicine, LIPIT, Campus Gasthuisberg, Katholieke Universiteit Leuven, Herestraat, Leuven, Belgium
| | - Mary C. Hunt
- Dublin Institute of Technology, School of Biological Sciences, Kevin Street, Dublin 8, Ireland
| | - Stefan E. H. Alexson
- Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institutet, C1-74, Karolinska University Hospital, SE-141 86 Stockholm, Sweden
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32
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Kang HW, Ozdemir C, Kawano Y, LeClair KB, Vernochet C, Kahn CR, Hagen SJ, Cohen DE. Thioesterase superfamily member 2/Acyl-CoA thioesterase 13 (Them2/Acot13) regulates adaptive thermogenesis in mice. J Biol Chem 2013; 288:33376-86. [PMID: 24072708 DOI: 10.1074/jbc.m113.481408] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Members of the acyl-CoA thioesterase (Acot) gene family hydrolyze fatty acyl-CoAs, but their biological functions remain incompletely understood. Thioesterase superfamily member 2 (Them2; synonym Acot13) is enriched in oxidative tissues, associated with mitochondria, and relatively specific for long chain fatty acyl-CoA substrates. Using Them2(-/-) mice, we have demonstrated key roles for Them2 in regulating hepatic glucose and lipid metabolism. However, reduced body weights and decreased adiposity in Them2(-/-) mice observed despite increased food consumption were not well explained. To explore a role in thermogenesis, mice were exposed to ambient temperatures ranging from thermoneutrality (30 °C) to cold (4 °C). In response to short term (24-h) exposures to decreasing ambient temperatures, Them2(-/-) mice exhibited increased adaptive responses in physical activity, food consumption, and energy expenditure when compared with Them2(+/+) mice. By contrast, genotype-dependent differences were not observed in mice that were equilibrated (96 h) at each ambient temperature. In brown adipose tissue, the absence of Them2 was associated with reduced lipid droplets, alterations in the ultrastructure of mitochondria, and increased expression of thermogenic genes. Indicative of a direct regulatory role for Them2 in heat production, cultured primary brown adipocytes from Them2(-/-) mice exhibited increased norepinephrine-mediated triglyceride hydrolysis and increased rates of O2 consumption, together with elevated expression of thermogenic genes. At least in part by regulating intracellular fatty acid channeling, Them2 functions in brown adipose tissue to suppress adaptive increases in energy expenditure.
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Affiliation(s)
- Hye Won Kang
- From the Department of Medicine, Division of Gastroenterology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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Ersoy BA, Tarun A, D'Aquino K, Hancer NJ, Ukomadu C, White MF, Michel T, Manning BD, Cohen DE. Phosphatidylcholine transfer protein interacts with thioesterase superfamily member 2 to attenuate insulin signaling. Sci Signal 2013; 6:ra64. [PMID: 23901139 DOI: 10.1126/scisignal.2004111] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Phosphatidylcholine transfer protein (PC-TP) is a phospholipid-binding protein that is enriched in liver and that interacts with thioesterase superfamily member 2 (THEM2). Mice lacking either protein exhibit improved hepatic glucose homeostasis and are resistant to diet-induced diabetes. Insulin receptor substrate 2 (IRS2) and mammalian target of rapamycin complex 1 (mTORC1) are key effectors of insulin signaling, which is attenuated in diabetes. We found that PC-TP inhibited IRS2, as evidenced by insulin-independent IRS2 activation after knockdown, genetic ablation, or chemical inhibition of PC-TP. In addition, IRS2 was activated after knockdown of THEM2, providing support for a role for the interaction of PC-TP with THEM2 in suppressing insulin signaling. Additionally, we showed that PC-TP bound to tuberous sclerosis complex 2 (TSC2) and stabilized the components of the TSC1-TSC2 complex, which functions to inhibit mTORC1. Preventing phosphatidylcholine from binding to PC-TP disrupted interactions of PC-TP with THEM2 and TSC2, and disruption of the PC-TP-THEM2 complex was associated with increased activation of both IRS2 and mTORC1. In livers of mice with genetic ablation of PC-TP or that had been treated with a PC-TP inhibitor, steady-state amounts of IRS2 were increased, whereas those of TSC2 were decreased. These findings reveal a phospholipid-dependent mechanism that suppresses insulin signaling downstream of its receptor.
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Affiliation(s)
- Baran A Ersoy
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Horibata Y, Ando H, Itoh M, Sugimoto H. Enzymatic and transcriptional regulation of the cytoplasmic acetyl-CoA hydrolase ACOT12. J Lipid Res 2013; 54:2049-2059. [PMID: 23709691 DOI: 10.1194/jlr.m030163] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Acyl-CoA thioesterase 12 (ACOT12) is the major enzyme known to hydrolyze the thioester bond of acetyl-CoA in the cytosol in the liver. ACOT12 contains a catalytic thioesterase domain at the N terminus and a steroidogenic acute regulatory protein-related lipid transfer (START) domain at the C terminus. We investigated the effects of lipids (phospholipids, sphingolipids, fatty acids, and sterols) on ACOT12 thioesterase activity and found that the activity was inhibited by phosphatidic acid (PA) in a noncompetitive manner. In contrast, the enzymatic activity of a mutant form of ACOT12 lacking the START domain was not inhibited by the lipids. These results suggest that the START domain is important for regulation of ACOT12 activity by PA. We also found that PA could bind to thioesterase domain, but not to the START domain, and had no effect on ACOT12 dissociation. ACOT12 is detectable in the liver but not in hepatic cell lines such as HepG2, Hepa-1, and Fa2N-4. ACOT12 mRNA and protein levels in rat primary hepatocytes decreased following treatment with insulin. These results suggest that cytosolic acetyl-CoA levels in the liver are controlled by lipid metabolites and hormones, which result in allosteric enzymatic and transcriptional regulation of ACOT12.
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Affiliation(s)
- Yasuhiro Horibata
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
| | - Hiromi Ando
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
| | - Masahiko Itoh
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan
| | - Hiroyuki Sugimoto
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi 321-0293, Japan.
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Abstract
Members of the acyl-CoA thioesterase (Acot) gene family catalyze the hydrolysis of fatty acyl-CoA thioesters. Thioesterase superfamily member (Them) 1 (synonym: Acot11) is enriched in brown adipose tissue and is markedly upregulated when mice are exposed to cold ambient temperatures. In a recent study, we demonstrated that Them1−/− mice exhibit increased energy expenditure and are resistant to diet-induced obesity and its metabolic consequences. This mini-review places these findings in the context of an emerging understanding of Them/Acot genes.
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Li H, Gao F, Yu S, Jia M, Gong W. Molecular cloning, expression, purification and crystallographic analysis of zebrafish THEM2. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:1525-8. [PMID: 23192039 PMCID: PMC3509980 DOI: 10.1107/s1744309112043813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 10/22/2012] [Indexed: 11/10/2022]
Abstract
Thioesterase superfamily member 2 (THEM2) is essential for cell proliferation of mammalian cells. It belongs to the hotdog-fold thioesterase superfamily and catalyzes the hydrolysis of the thioester bonds of acyl-CoA in vitro. In this study, THEM2 protein from zebrafish (fTHEM2) was expressed in Escherichia coli and purified by Ni-affinity and gel-filtration chromatography. fTHEM2 crystals were obtained using the sitting-drop vapour-diffusion method with PEG 10 000 as precipitant. X-ray diffraction data were collected to 1.80 Å resolution using a synchrotron-radiation source. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a=77.1, b=74.4, c=96.6 Å, β=93.7°.
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Affiliation(s)
- Han Li
- Laboratory of Non-coding RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, People’s Republic of China
- Graduate University, Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Feng Gao
- Laboratory of Non-coding RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, People’s Republic of China
| | - Shanshan Yu
- Laboratory of Non-coding RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, People’s Republic of China
| | - Minze Jia
- Laboratory of Non-coding RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, People’s Republic of China
| | - Weimin Gong
- Laboratory of Non-coding RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, People’s Republic of China
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Han S, Cohen DE. Functional characterization of thioesterase superfamily member 1/Acyl-CoA thioesterase 11: implications for metabolic regulation. J Lipid Res 2012; 53:2620-31. [PMID: 22993230 DOI: 10.1194/jlr.m029538] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thioesterase superfamily member 1 (Them1; synonyms acyl-CoA thioesterase 11 and StarD14) is highly expressed in brown adipose tissue and limits energy expenditure in mice. Them1 is a putative fatty acyl-CoA thioesterase that comprises tandem hot dog-fold thioesterase domains and a lipid-binding C-terminal steroidogenic acute regulatory protein-related lipid transfer (START) domain. To better define its role in metabolic regulation, this study examined the biochemical and enzymatic properties of Them1. Purified recombinant Them1 dimerized in solution to form an active fatty acyl-CoA thioesterase. Dimerization was induced by fatty acyl-CoAs, coenzyme A (CoASH), ATP, and ADP. Them1 hydrolyzed a range of fatty acyl-CoAs but exhibited a relative preference for long-chain molecular species. Thioesterase activity varied inversely with temperature, was stimulated by ATP, and was inhibited by ADP and CoASH. Whereas the thioesterase domains of Them1 alone were sufficient to yield active recombinant protein, the START domain was required for optimal enzyme activity. An analysis of subcellular fractions from mouse brown adipose tissue and liver revealed that Them1 contributes principally to the fatty acyl-CoA thioesterase activity of microsomes and nuclei. These findings suggest that under biological conditions, Them1 functions as a lipid-regulated fatty acyl-CoA thioesterase that could be targeted for the management of metabolic disorders.
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Affiliation(s)
- Shuxin Han
- Department of Medicine, Division of Gastroenterology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Kang HW, Niepel MW, Han S, Kawano Y, Cohen DE. Thioesterase superfamily member 2/acyl-CoA thioesterase 13 (Them2/Acot13) regulates hepatic lipid and glucose metabolism. FASEB J 2012; 26:2209-21. [PMID: 22345407 DOI: 10.1096/fj.11-202853] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Members of the acyl-CoA thioesterase (Acot) gene family catalyze the hydrolysis of fatty acyl-CoAs, but their biological functions remain unknown. Thioesterase superfamily member 2 (Them2; synonym Acot13) is a broadly expressed mitochondria-associated Acot. Them2 was previously identified as an interacting protein of phosphatidylcholine transfer protein (PC-TP). Pctp(-/-) mice exhibit altered fatty acid metabolism that is accompanied by reduced hepatic glucose production. To examine the role of Them2 in regulating hepatic lipid and glucose homeostasis, we generated Them2(-/-) mice. In livers of Them2(-/-) mice compared with Them2(+/+) controls, a 1.9-fold increase in the K(m) of mitochondrial thioesterase activity was accompanied by a 28% increase in fatty acyl-CoA concentration. A reciprocal 23% decrease in free fatty acid concentration was associated with reduced activation of peroxisome proliferator-activated receptor α. However, fatty acid oxidation rates were preserved in livers of Them2(-/-) mice, suggesting that Them2 functions to limit β-oxidation. Hepatic glucose production was also decreased by 45% in the setting of reduced hepatocyte nuclear factor 4α (HNF4α) expression. When fed a high-fat diet, Them2(-/-) mice were resistant to increases in hepatic glucose production and steatosis. These findings reveal key roles for Them2 in the regulation of hepatic metabolism, which are potentially mediated by PC-TP-Them2 interactions.
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Affiliation(s)
- Hye Won Kang
- Department of Medicine, Division of Gastroenterology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Ren Q, Zhao XF, Wang JX. Potential role of single hotdog fold thioesterase in the antiviral response of Fenneropenaeus chinensis. FISH & SHELLFISH IMMUNOLOGY 2011; 30:1192-1196. [PMID: 21362487 DOI: 10.1016/j.fsi.2011.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 02/15/2011] [Accepted: 02/20/2011] [Indexed: 05/30/2023]
Abstract
Thioesterase superfamily member 2 (Them2) is a single hotdog fold thioesterase domain-containing protein. Its biological function is not well known. Recently, a hotdog fold thioesterase (FcThem) was cloned for the first time from the Chinese white shrimp. The full length of FcThem is 748bp. It encodes a protein with 142 amino acids with a predicted molecular mass of 14.79kDa and an isoelectric point of 8.76. No signal peptide was predicted. Multiple alignment of FcThem with other Them2 proteins suggested a conserved HGG motif. Phylogenetic analysis showed that FcThem were clustered with vertebrate Them2 protein into one group. The RT-PCR results showed that FcThem was a widely distributed gene and could be detected in the hemocytes, heart, hepatopancreas, gills, stomach, intestines, and ovaries of unchallenged shrimps. In hemocytes, its transcript was upregulated 24h post WSSV challenge. In the gills, the FcThem went up at a 6h WSSV challenge. FcThem expression in the ovaries was also affected by the WSSV and was increased after the 2h WSSV challenge, reaching the highest level at 6h. Our results show that FcThem probably has roles in the innate immunity system of shrimps and investigations will be carried out to explore this finding further.
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Affiliation(s)
- Qian Ren
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China
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40
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Brocker C, Carpenter C, Nebert DW, Vasiliou V. Evolutionary divergence and functions of the human acyl-CoA thioesterase gene ( ACOT ) family. Hum Genomics 2011; 4:411-20. [PMID: 20846931 PMCID: PMC3525216 DOI: 10.1186/1479-7364-4-6-411] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The acyl-CoA thioesterase gene (ACOT) family encodes enzymes that catalyse the hydrolysis of acyl-CoA thioester compounds, also known as activated fatty acids, to their corresponding non-esterified (free) fatty acid and coenzyme A (CoASH). These enzymes play a very important role in lipid metabolism by maintaining cellular levels and proper ratios of free and activated fatty acids, as well as CoASH. Within the acyl-CoA family there are two distinct subgroups, type I and type II. Despite catalysing the same reaction, the two groups are not structurally similar and do not share sequence homology, strongly suggesting convergent evolution. This suggestion is further supported if one compares the human with the mouse and rat ACOT gene families. To date, four human type I ACOTs have been identified which belong to the α/β-hydrolase fold enzyme superfamily. Type II ACOTs fall into the 'hot dog' fold superfamily. There are currently six human type II genes; however, two homologous proteins, thioesterase superfamily members 4 (THEM4) and 5 (THEM5) share common type II structural features and, in the case of THEM4, acyl-CoA thioesterase activity -- suggesting that the family may be larger than previously realised. Although recent studies have greatly expanded the current understanding of these proteins and their physiological importance, there are a number of members whose functions are relatively unexplored and which warrant further investigation.
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Affiliation(s)
- Chad Brocker
- Molecular Toxicology and Environmental Health Sciences Program, Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO 80045, USA
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41
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Cantu DC, Chen Y, Reilly PJ. Thioesterases: a new perspective based on their primary and tertiary structures. Protein Sci 2010; 19:1281-95. [PMID: 20506386 DOI: 10.1002/pro.417] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Thioesterases (TEs) are classified into EC 3.1.2.1 through EC 3.1.2.27 based on their activities on different substrates, with many remaining unclassified (EC 3.1.2.-). Analysis of primary and tertiary structures of known TEs casts a new light on this enzyme group. We used strong primary sequence conservation based on experimentally proved proteins as the main criterion, followed by verification with tertiary structure superpositions, mechanisms, and catalytic residue positions, to accurately define TE families. At present, TEs fall into 23 families almost completely unrelated to each other by primary structure. It is assumed that all members of the same family have essentially the same tertiary structure; however, TEs in different families can have markedly different folds and mechanisms. Conversely, the latter sometimes have very similar tertiary structures and catalytic mechanisms despite being only slightly or not at all related by primary structure, indicating that they have common distant ancestors and can be grouped into clans. At present, four clans encompass 12 TE families. The new constantly updated ThYme (Thioester-active enzYmes) database contains TE primary and tertiary structures, classified into families and clans that are different from those currently found in the literature or in other databases. We review all types of TEs, including those cleaving CoA, ACP, glutathione, and other protein molecules, and we discuss their structures, functions, and mechanisms.
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Affiliation(s)
- David C Cantu
- Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011, USA
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42
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Kang HW, Wei J, Cohen DE. PC-TP/StARD2: Of membranes and metabolism. Trends Endocrinol Metab 2010; 21:449-56. [PMID: 20338778 PMCID: PMC2897958 DOI: 10.1016/j.tem.2010.02.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 02/03/2010] [Accepted: 02/04/2010] [Indexed: 11/25/2022]
Abstract
Phosphatidylcholine transfer protein (PC-TP, synonym StARD2) binds phosphatidylcholines, and catalyzes their intermembrane transfer and exchange in vitro. The structure of PC-TP comprises a hydrophobic pocket and a well-defined head group binding site, and its gene expression is regulated by peroxisome proliferator activated receptor-alpha. Recent studies have revealed key regulatory roles for PC-TP in lipid and glucose metabolism. Notably, Pctp(-/-) mice are sensitized to the action of insulin, and exhibit more efficient brown fat-mediated thermogenesis. PC-TP appears to limit access of fatty acids to mitochondria by stimulating the activity of thioesterase superfamily member 2, a newly characterized long-chain fatty acyl-coenzyme A thioesterase. Because PC-TP discriminates between phosphatidylcholines within lipid bilayers, it might function as a sensor that links metabolic regulation to membrane composition.
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Affiliation(s)
- Hye Won Kang
- Department of Medicine, Division of Gastroenterology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Kirkby B, Roman N, Kobe B, Kellie S, Forwood JK. Functional and structural properties of mammalian acyl-coenzyme A thioesterases. Prog Lipid Res 2010; 49:366-77. [PMID: 20470824 DOI: 10.1016/j.plipres.2010.04.001] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 04/23/2010] [Accepted: 04/26/2010] [Indexed: 10/19/2022]
Abstract
Acyl-coenzyme A thioesterases (Acots) play important cellular roles in mammalian fatty acid metabolism through modulation of cellular concentrations of activated fatty acyl-CoAs. Acots catalyse the hydrolysis of the thioester bond present within acyl-CoA ester molecules to yield coenzyme A (CoASH) and the corresponding non-esterified fatty acid. Acyl-CoA thioesterases are expressed ubiquitously in both prokaryotes and eukaryotes and, in higher order organisms, the enzymes are expressed and localised in a tissue-dependent manner within the cytosol, mitochondria, peroxisomes and endoplasmic reticulum. Recent studies have led to advances in the functional and structural characterization of many mammalian Acot family members. These include the structure determination of both type-I and type-II Acot family members, structural elucidation of the START domain of ACOT11, identification of roles in arachidonic acid and inflammatory prostaglandin production by Acot7, and inclusion of a 13th Acot family member. Here, we review and analyse the current literature on mammalian Acots with respect to their characterization and summarize the current knowledge on the structure, function and regulation of this enzyme family.
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Affiliation(s)
- Brenda Kirkby
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2650, Australia
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44
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Kang HW, Kanno K, Scapa EF, Cohen DE. Regulatory role for phosphatidylcholine transfer protein/StarD2 in the metabolic response to peroxisome proliferator activated receptor alpha (PPARalpha). Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:496-502. [PMID: 20045742 DOI: 10.1016/j.bbalip.2009.12.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 11/25/2009] [Accepted: 12/24/2009] [Indexed: 10/20/2022]
Abstract
Phosphatidylcholine transfer protein (PC-TP, a.k.a. StarD2) is abundantly expressed in liver and is regulated by PPARalpha. When fed the synthetic PPARalpha ligand fenofibrate, Pctp(-/-) mice exhibited altered lipid and glucose metabolism. Microarray profiling of livers from fenofibrate fed wild type and Pctp(-/-) mice revealed differential expression of a broad array of metabolic genes, as well as their regulatory transcription factors. PC-TP expression in cell culture controlled the activities of both PPARalpha and HNF4alpha, suggesting that the mechanism by which it modulates hepatic metabolism is at least in part via activation of transcription factors that govern nutrient homeostasis.
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Affiliation(s)
- Hye Won Kang
- Department of Medicine, Division of Gastroenterology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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45
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Montero-Moran G, Caviglia JM, McMahon D, Rothenberg A, Subramanian V, Xu Z, Lara-Gonzalez S, Storch J, Carman GM, Brasaemle DL. CGI-58/ABHD5 is a coenzyme A-dependent lysophosphatidic acid acyltransferase. J Lipid Res 2009; 51:709-19. [PMID: 19801371 DOI: 10.1194/jlr.m001917] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Mutations in human CGI-58/ABHD5 cause Chanarin-Dorfman syndrome (CDS), characterized by excessive storage of triacylglycerol in tissues. CGI-58 is an alpha/beta-hydrolase fold enzyme expressed in all vertebrates. The carboxyl terminus includes a highly conserved consensus sequence (HXXXXD) for acyltransferase activity. Mouse CGI-58 was expressed in Escherichia coli as a fusion protein with two amino terminal 6-histidine tags. Recombinant CGI-58 displayed acyl-CoA-dependent acyltransferase activity to lysophosphatidic acid, but not to other lysophospholipid or neutral glycerolipid acceptors. Production of phosphatidic acid increased with time and increasing concentrations of recombinant CGI-58 and was optimal between pH 7.0 and 8.5. The enzyme showed saturation kinetics with respect to 1-oleoyl-lysophosphatidic acid and oleoyl-CoA and preference for arachidonoyl-CoA and oleoyl-CoA. The enzyme showed slight preference for 1-oleoyl lysophosphatidic acid over 1-palmitoyl, 1-stearoyl, or 1-arachidonoyl lysophosphatidic acid. Recombinant CGI-58 showed intrinsic fluorescence for tryptophan that was quenched by the addition of 1-oleoyl-lysophosphatidic acid, oleoyl-CoA, arachidonoyl-CoA, and palmitoyl-CoA, but not by lysophosphatidyl choline. Expression of CGI-58 in fibroblasts from humans with CDS increased the incorporation of radiolabeled fatty acids released from the lipolysis of stored triacylglycerols into phospholipids. CGI-58 is a CoA-dependent lysophosphatidic acid acyltransferase that channels fatty acids released from the hydrolysis of stored triacylglycerols into phospholipids.
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Affiliation(s)
- Gabriela Montero-Moran
- Rutgers Center for Lipid Research, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
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46
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Kang HW, Ribich S, Kim BW, Hagen SJ, Bianco AC, Cohen DE. Mice lacking Pctp /StarD2 exhibit increased adaptive thermogenesis and enlarged mitochondria in brown adipose tissue. J Lipid Res 2009; 50:2212-21. [PMID: 19502644 DOI: 10.1194/jlr.m900013-jlr200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pctp(-/-) mice that lack phosphatidylcholine transfer protein (Pctp) exhibit a marked shift toward utilization of fatty acids for oxidative phosphorylation, suggesting that Pctp may regulate the entry of fatty acyl-CoAs into mitochondria. Here, we examined the influence of Pctp expression on the function and structure of brown adipose tissue (BAT), a mitochondrial-rich, oxidative tissue that mediates nonshivering thermogenesis. Consistent with increased thermogenesis, Pctp(-/-) mice exhibited higher core body temperatures than wild-type controls at room temperature. During a 24 h cold challenge, Pctp(-/-) mice defended core body temperature efficiently enough that acute, full activation of BAT thermogenic genes did not occur. Brown adipocytes lacking Pctp harbored enlarged and elongated mitochondria. Consistent with increased fatty acid utilization, brown adipocytes cultured from Pctp(-/-) mice exhibited higher oxygen consumption rates in response to norepinephrine. The absence of Pctp expression during brown adipogenesis in vitro altered the expression of key transcription factors, which could be corrected by adenovirus-mediated overexpression of Pctp early but not late during the differentiation. Collectively, these findings support a key role for Pctp in limiting mitochondrial oxidation of fatty acids and thus regulating adaptive thermogenesis in BAT.
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Affiliation(s)
- Hye Won Kang
- Department of Medicine, Division of Gastroenterology, Harvard Medical School, Boston, MA, USA
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