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He J, Liu K, Zheng S, Wu Y, Zhao C, Yan S, Liu L, Ruan K, Ma X, Fu C. The Acyl-CoA-Binding Protein Acb1 regulates mitochondria, lipid droplets, and cell proliferation. FEBS Lett 2022; 596:1795-1808. [PMID: 35658118 DOI: 10.1002/1873-3468.14415] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/14/2022] [Accepted: 05/30/2022] [Indexed: 11/07/2022]
Abstract
Mitochondria are involved in many cellular activities, including energy metabolism and biosynthesis of nucleotides, fatty acids, and amino acids. Mitochondrial morphology is a key factor in dictating mitochondrial functions. Here, we report that the acyl-CoA binding protein Acb1 in the fission yeast Schizosaccharomyces pombe is required for the maintenance of tubular mitochondrial morphology and proper mitochondrial respiration. The absence of Acb1 causes severe mitochondrial fragmentation in a dynamin-related protein Dnm1-dependent manner and impairs mitochondrial respiration. Moreover, Acb1 regulates the remodeling of lipid droplets in nutrient-rich conditions. Importantly, Acb1 promotes cell survival when cells are cultured in nutrient-rich medium. Hence, our findings establish roles of acyl-CoA binding proteins in regulating mitochondria, lipid droplets, and cell viability.
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Affiliation(s)
- Jiajia He
- MOE Key Laboratory for Cellular Dynamics & School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 230027
| | - Ke Liu
- MOE Key Laboratory for Cellular Dynamics & School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 230027
| | - Shengnan Zheng
- MOE Key Laboratory for Cellular Dynamics & School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 230027
| | - Yifan Wu
- MOE Key Laboratory for Cellular Dynamics & School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 230027
| | - Chenhui Zhao
- MOE Key Laboratory for Cellular Dynamics & School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 230027
| | - Shuaijie Yan
- MOE Key Laboratory for Cellular Dynamics & School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 230027
| | - Ling Liu
- MOE Key Laboratory for Cellular Dynamics & School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 230027
| | - Ke Ruan
- MOE Key Laboratory for Cellular Dynamics & School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 230027
| | - Xiaopeng Ma
- Department of General Surgery, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, People's Republic of China
| | - Chuanhai Fu
- MOE Key Laboratory for Cellular Dynamics & School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 230027
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2
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Yan Y, Tang J, Yuan Q, Liu L, Liu H, Huang J, Hsiang T, Zheng L. iTRAQ-Based Quantitative Proteomics Reveals ChAcb1 as a Novel Virulence Factor in Colletotrichum higginsianum. PHYTOPATHOLOGY 2021; 111:1571-1582. [PMID: 33567906 DOI: 10.1094/phyto-01-21-0028-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Colletotrichum higginsianum is an important hemibiotrophic fungal pathogen that causes anthracnose disease on various cruciferous plants. Discovery of new virulence factors could lead to strategies for effectively controlling anthracnose. Acyl-CoA binding proteins (ACBPs) are mainly involved in binding and trafficking acyl-CoA esters in eukaryotic cells. However, the functions of this important class of proteins in plant fungal pathogens remain unclear. In this study, we performed an isobaric tags for relative and absolute quantification (iTRAQ)-based quantitative proteomic analysis to identify differentially expressed proteins (DEPs) between a nonpathogenic mutant ΔCh-MEL1 and the wild type. Based on iTRAQ data, DEPs in the ΔCh-MEL1 mutant were mainly associated with melanin biosynthesis, carbohydrate and energy metabolism, lipid metabolism, redox processes, and amino acid metabolism. Proteomic analysis revealed that many DEPs might be involved in growth and pathogenesis of C. higginsianum. Among them, an acyl-CoA binding protein, ChAcb1, was selected for further functional studies. Deletion of ChAcb1 caused defects in vegetative growth and conidiation. ChAcb1 is also required for response to hyperosmotic and oxidative stresses, and maintenance of cell wall integrity. Importantly, the ΔChAcb1 mutant exhibited reduced virulence, and microscopic examination revealed that it was defective in appressorial penetration and infectious growth. Furthermore, the ΔChAcb1 mutant was impaired in fatty acid and lipid metabolism. Taken together, ChAcb1 was identified as a new virulence gene in this plant pathogenic fungus.
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Affiliation(s)
- Yaqin Yan
- Hubei Key Laboratory of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China
- Institute of Vegetables Research, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Jintian Tang
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Qinfeng Yuan
- Hubei Key Laboratory of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China
| | - Liping Liu
- Laboratory of Plant Pathology, Department of Agronomy, Jilin Agricultural University, Changchun 130118, China
| | - Hao Liu
- Hubei Key Laboratory of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China
| | - Junbin Huang
- Hubei Key Laboratory of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph N1G 2W1, Ontario, Canada
| | - Lu Zheng
- Hubei Key Laboratory of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China
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3
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Tambellini NP, Zaremberg V, Krishnaiah S, Turner RJ, Weljie AM. Primary Metabolism and Medium-Chain Fatty Acid Alterations Precede Long-Chain Fatty Acid Changes Impacting Neutral Lipid Metabolism in Response to an Anticancer Lysophosphatidylcholine Analogue in Yeast. J Proteome Res 2017; 16:3741-3752. [PMID: 28849941 DOI: 10.1021/acs.jproteome.7b00430] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The nonmetabolizable lysophosphatidylcholine (LysoPC) analogue edelfosine is the prototype of a class of compounds being investigated for their potential as selective chemotherapeutic agents. Edelfosine targets membranes, disturbing cellular homeostasis. Is not clear at this point how membrane alterations are communicated between intracellular compartments leading to growth inhibition and eventual cell death. In the present study, a combined metabolomics/lipidomics approach for the unbiased identification of metabolic pathways altered in yeast treated with sublethal concentrations of the LysoPC analogue was employed. Mass spectrometry of polar metabolites, fatty acids, and lipidomic profiling was used to study the effects of edelfosine on yeast metabolism. Amino acid and sugar metabolism, the Krebs cycle, and fatty acid profiles were most disrupted, with polar metabolites and short-medium chain fatty acid changes preceding long and very long-chain fatty acid variations. Initial increases in metabolites such as trehalose, proline, and γ-amino butyric acid with a concomitant decrease in metabolites of the Krebs cycle, citrate and fumarate, are interpreted as a cellular attempt to offset oxidative stress in response to mitochondrial dysfunction induced by the treatment. Notably, alanine, inositol, and myristoleic acid showed a steady increase during the period analyzed (2, 4, and 6 h after treatment). Of importance was the finding that edelfosine induced significant alterations in neutral glycerolipid metabolism resulting in a significant increase in the signaling lipid diacylglycerol.
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Affiliation(s)
- Nicolas P Tambellini
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada.,Metabolomics Research Centre, University of Calgary , Calgary, Alberta T2N 1N4, Canada
| | - Vanina Zaremberg
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada
| | - Saikumari Krishnaiah
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine , Philadelphia, Pennsylvania 19104-5158, United States of America
| | - Raymond J Turner
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada
| | - Aalim M Weljie
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada.,Metabolomics Research Centre, University of Calgary , Calgary, Alberta T2N 1N4, Canada.,Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine , Philadelphia, Pennsylvania 19104-5158, United States of America
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4
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Lipidomics in research on yeast membrane lipid homeostasis. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:797-799. [PMID: 28219720 DOI: 10.1016/j.bbalip.2017.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/13/2017] [Accepted: 02/15/2017] [Indexed: 11/21/2022]
Abstract
Mass spectrometry is increasingly used in research on membrane lipid homeostasis, both in analyses of the steady state lipidome at the level of molecular lipid species, and in pulse-chase approaches employing stable isotope-labeled lipid precursors addressing the dynamics of lipid metabolism. Here my experience with, and view on mass spectrometry-based lipid analysis is presented, with emphasis on aspects of quantification of membrane lipid composition of the yeast Saccharomyces cerevisiae. This article is part of a Special Issue entitled: BBALIP_Lipidomics Opinion Articles edited by Sepp Kohlwein.
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5
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Tyurina YY, Lou W, Qu F, Tyurin VA, Mohammadyani D, Liu J, Hüttemann M, Frasso MA, Wipf P, Bayir H, Greenberg ML, Kagan VE. Lipidomics Characterization of Biosynthetic and Remodeling Pathways of Cardiolipins in Genetically and Nutritionally Manipulated Yeast Cells. ACS Chem Biol 2017; 12:265-281. [PMID: 27982579 PMCID: PMC5578713 DOI: 10.1021/acschembio.6b00995] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cardioipins (CLs) are unique tetra-acylated phospholipids of mitochondria and define the bioenergetics and regulatory functions of these organelles. An unresolved paradox is the high uniformity of CL molecular species (tetra-linoleoyl-CL) in the heart, liver, and skeletal muscles-in contrast to their high diversification in the brain. Here, we combined liquid chromatography-mass-spectrometry-based phospholipidomics with genetic and nutritional manipulations to explore CLs' biosynthetic vs postsynthetic remodeling processes in S. cerevisiae yeast cells. By applying the differential phospholipidomics analysis, we evaluated the contribution of Cld1 (CL-specific phospholipase A) and Taz1 (acyl-transferase) as the major regulatory mechanisms of the remodeling process. We further established that nutritional "pressure" by high levels of free fatty acids triggered a massive synthesis of homoacylated molecular species in all classes of phospholipids, resulting in the preponderance of the respective homoacylated CLs. We found that changes in molecular speciation of CLs induced by exogenous C18-fatty acids (C18:1 and C18:2) in wild-type (wt) cells did not occur in any of the remodeling mutant cells, including cld1Δ, taz1Δ, and cld1Δtaz1Δ. Interestingly, molecular speciation of CLs in wt and double mutant cells cld1Δtaz1Δ was markedly different. Given that the bioenergetics functions are preserved in the double mutant, this suggests that the accumulated MLCL-rather than the changed CL speciation-are the likely major contributors to the mitochondrial dysfunction in taz1Δ mutant cells (also characteristic of Barth syndrome). Biochemical studies of Cld1 specificity and computer modeling confirmed the hydrolytic selectivity of the enzyme toward C16-CL substrates and the preservation of C18:1-containing CL species.
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Affiliation(s)
- Yulia Y. Tyurina
- Department of Environmental Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Wenjia Lou
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States
| | - Feng Qu
- Department of Environmental Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Vladimir A Tyurin
- Department of Environmental Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Dariush Mohammadyani
- Department of Environmental Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, United States
| | - Jenney Liu
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, Michigan, United States
| | - Maik Hüttemann
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, Michigan, United States
| | - Michael A. Frasso
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Hülya Bayir
- Department of Environmental Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Miriam. L. Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States
| | - Valerian E. Kagan
- Department of Environmental Health and Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
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6
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Pennington ER, Fix A, Sullivan EM, Brown DA, Kennedy A, Shaikh SR. Distinct membrane properties are differentially influenced by cardiolipin content and acyl chain composition in biomimetic membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1859:257-267. [PMID: 27889304 DOI: 10.1016/j.bbamem.2016.11.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 12/14/2022]
Abstract
Cardiolipin (CL) has a critical role in maintaining mitochondrial inner membrane structure. In several conditions such as heart failure and aging, there is loss of CL content and remodeling of CL acyl chains, which are hypothesized to impair mitochondrial inner membrane biophysical organization. Therefore, this study discriminated how CL content and acyl chain composition influenced select properties of simple and complex mitochondrial mimicking model membranes. We focused on monolayer excess area/molecule (a measure of lipid miscibility), bilayer phase transitions, and microdomain organization. In monolayer compression studies, loss of tetralinoleoyl [(18:2)4] CL content decreased the excess area/molecule. Replacement of (18:2)4CL acyl chains with tetraoleoyl [(18:1)4] CL or tetradocosahexaenoyl [(22:6)4] CL generally had little influence on monolayer excess area/molecule; in contrast, replacement of (18:2)4CL acyl chains with tetramyristoyl [(14:0)4] CL increased monolayer excess area/molecule. In bilayers, calorimetric studies showed that substitution of (18:2)4CL with (18:1)4CL or (22:6)4CL lowered the phase transition temperature of phosphatidylcholine vesicles whereas (14:0)4CL had no effect. Finally, quantitative imaging of giant unilamellar vesicles revealed differential effects of CL content and acyl chain composition on microdomain organization, visualized with the fluorescent probe Texas Red DHPE. Notably, microdomain areas were decreased by differing magnitudes upon lowering of (18:2)4CL content and substitution of (18:2)4CL with (14:0)4CL or (22:6)4CL. Conversely, exchanging (18:2)4CL with (18:1)4CL increased microdomain area. Altogether, these data demonstrate that CL content and fatty acyl composition differentially target membrane physical properties, which has implications for understanding how CL regulates mitochondrial activity and the design of CL-specific therapeutics.
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Affiliation(s)
- Edward Ross Pennington
- Department of Biochemistry & Molecular Biology, USA; East Carolina Diabetes & Obesity Institute, Brody School of Medicine, East Carolina University, 115 Heart Drive, Mail Stop 743, Greenville, NC 27834, USA
| | - Amy Fix
- Department of Biochemistry & Molecular Biology, USA
| | - E Madison Sullivan
- Department of Biochemistry & Molecular Biology, USA; East Carolina Diabetes & Obesity Institute, Brody School of Medicine, East Carolina University, 115 Heart Drive, Mail Stop 743, Greenville, NC 27834, USA
| | - David A Brown
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech Corporate Research Center, 1035 ILSB, 1981 Kraft Drive, Blacksburg, VA 24060, USA
| | - Anthony Kennedy
- Department of Chemistry, East 10th Street, Mail Stop 552, East Carolina University, Greenville, NC 27854, USA
| | - Saame Raza Shaikh
- Department of Biochemistry & Molecular Biology, USA; East Carolina Diabetes & Obesity Institute, Brody School of Medicine, East Carolina University, 115 Heart Drive, Mail Stop 743, Greenville, NC 27834, USA.
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7
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Renne MF, Bao X, De Smet CH, de Kroon AIPM. Lipid Acyl Chain Remodeling in Yeast. Lipid Insights 2016; 8:33-40. [PMID: 26819558 PMCID: PMC4720183 DOI: 10.4137/lpi.s31780] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 11/21/2015] [Indexed: 11/05/2022] Open
Abstract
Membrane lipid homeostasis is maintained by de novo synthesis, intracellular transport, remodeling, and degradation of lipid molecules. Glycerophospholipids, the most abundant structural component of eukaryotic membranes, are subject to acyl chain remodeling, which is defined as the post-synthetic process in which one or both acyl chains are exchanged. Here, we review studies addressing acyl chain remodeling of membrane glycerophospholipids in Saccharomyces cerevisiae, a model organism that has been successfully used to investigate lipid synthesis and its regulation. Experimental evidence for the occurrence of phospholipid acyl chain exchange in cardiolipin, phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine is summarized, including methods and tools that have been used for detecting remodeling. Progress in the identification of the enzymes involved is reported, and putative functions of acyl chain remodeling in yeast are discussed.
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Affiliation(s)
- Mike F Renne
- Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Institute of Biomembranes, Utrecht University, Utrecht, the Netherlands
| | - Xue Bao
- Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Institute of Biomembranes, Utrecht University, Utrecht, the Netherlands
| | - Cedric H De Smet
- Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Institute of Biomembranes, Utrecht University, Utrecht, the Netherlands.; Present address: Division of Cell Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Anton I P M de Kroon
- Membrane Biochemistry and Biophysics, Bijvoet Center for Biomolecular Research, Institute of Biomembranes, Utrecht University, Utrecht, the Netherlands
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8
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Secreted Acb1 Contributes to the Yeast-to-Hypha Transition in Cryptococcus neoformans. Appl Environ Microbiol 2015; 82:1069-1079. [PMID: 26637591 DOI: 10.1128/aem.03691-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 11/23/2015] [Indexed: 01/30/2023] Open
Abstract
Adaptation to stress by eukaryotic pathogens is often accompanied by a transition in cellular morphology. The human fungal pathogen Cryptococcus neoformans is known to switch between the yeast and the filamentous form in response to amoebic predation or during mating. As in the classic dimorphic fungal pathogens, the morphotype is associated with the ability of cryptococci to infect various hosts. Many cryptococcal factors and environmental stimuli, including pheromones (small peptides) and nutrient limitation, are known to induce the yeast-to-hypha transition. We recently discovered that secreted matricellular proteins could also act as intercellular signals to promote the yeast-to-hypha transition. Here we show that the secreted acyl coenzyme A (acyl-CoA)-binding protein Acb1 plays an important role in enhancing this morphotype transition. Acb1 does not possess a signal peptide. Its extracellular secretion and, consequently, its function in filamentation are dependent on an unconventional GRASP (Golgi reassembly stacking protein)-dependent secretion pathway. Surprisingly, intracellular recruitment of Acb1 to the secretory vesicles is independent of Grasp. In addition to Acb1, Grasp possibly controls the secretion of other cargos, because the graspΔ mutant, but not the acb1Δ mutant, is defective in capsule production and macrophage phagocytosis. Nonetheless, Acb1 is likely the major or the sole effector of Grasp in terms of filamentation. Furthermore, we found that the key residue of Acb1 for acyl binding, Y80, is critical for the proper subcellular localization and secretion of Acb1 and for cryptococcal morphogenesis.
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9
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Klug L, Daum G. Yeast lipid metabolism at a glance. FEMS Yeast Res 2014; 14:369-88. [DOI: 10.1111/1567-1364.12141] [Citation(s) in RCA: 199] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/23/2014] [Accepted: 02/02/2014] [Indexed: 01/07/2023] Open
Affiliation(s)
- Lisa Klug
- Institute of Biochemistry; Graz University of Technology; Graz Austria
| | - Günther Daum
- Institute of Biochemistry; Graz University of Technology; Graz Austria
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10
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Qiu Y, Fakas S, Han GS, Barbosa AD, Siniossoglou S, Carman GM. Transcription factor Reb1p regulates DGK1-encoded diacylglycerol kinase and lipid metabolism in Saccharomyces cerevisiae. J Biol Chem 2013; 288:29124-33. [PMID: 23970552 PMCID: PMC3790011 DOI: 10.1074/jbc.m113.507392] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the yeast Saccharomyces cerevisiae, the DGK1-encoded diacylglycerol kinase catalyzes the CTP-dependent phosphorylation of diacylglycerol to form phosphatidate. This enzyme, in conjunction with PAH1-encoded phosphatidate phosphatase, controls the levels of phosphatidate and diacylglycerol for phospholipid synthesis, membrane growth, and lipid droplet formation. In this work, we showed that a functional level of diacylglycerol kinase is regulated by the Reb1p transcription factor. In the electrophoretic mobility shift assay, purified recombinant Reb1p was shown to specifically bind its consensus recognition sequence (CGGGTAA, -166 to -160) in the DGK1 promoter. Analysis of cells expressing the PDGK1-lacZ reporter gene showed that mutations (GT→TG) in the Reb1p-binding sequence caused an 8.6-fold reduction in β-galactosidase activity. The expression of DGK1(reb1), a DGK1 allele containing the Reb1p-binding site mutation, was greatly lower than that of the wild type allele, as indicated by analyses of DGK1 mRNA, Dgk1p, and diacylglycerol kinase activity. In the presence of cerulenin, an inhibitor of de novo fatty acid synthesis, the dgk1Δ mutant expressing DGK1(reb1) exhibited a significant defect in growth as well as in the synthesis of phospholipids from triacylglycerol mobilization. Unlike DGK1, the DGK1(reb1) expressed in the dgk1Δ pah1Δ mutant did not result in the nuclear/endoplasmic reticulum membrane expansion, which occurs in cells lacking phosphatidate phosphatase activity. Taken together, these results indicate that the Reb1p-mediated regulation of diacylglycerol kinase plays a major role in its in vivo functions in lipid metabolism.
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Affiliation(s)
- Yixuan Qiu
- From the Department of Food Science, Rutgers Center for Lipid Research, and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901 and
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11
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Checks and balances in membrane phospholipid class and acyl chain homeostasis, the yeast perspective. Prog Lipid Res 2013; 52:374-94. [PMID: 23631861 DOI: 10.1016/j.plipres.2013.04.006] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 03/28/2013] [Accepted: 04/16/2013] [Indexed: 11/24/2022]
Abstract
Glycerophospholipids are the most abundant membrane lipid constituents in most eukaryotic cells. As a consequence, phospholipid class and acyl chain homeostasis are crucial for maintaining optimal physical properties of membranes that in turn are crucial for membrane function. The topic of this review is our current understanding of membrane phospholipid homeostasis in the reference eukaryote Saccharomyces cerevisiae. After introducing the physical parameters of the membrane that are kept in optimal range, the properties of the major membrane phospholipids and their contributions to membrane structure and dynamics are summarized. Phospholipid metabolism and known mechanisms of regulation are discussed, including potential sensors for monitoring membrane physical properties. Special attention is paid to processes that maintain the phospholipid class specific molecular species profiles, and to the interplay between phospholipid class and acyl chain composition when yeast membrane lipid homeostasis is challenged. Based on the reviewed studies, molecular species selectivity of the lipid metabolic enzymes, and mass action in acyl-CoA metabolism are put forward as important intrinsic contributors to membrane lipid homeostasis.
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12
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De Smet CH, Cox R, Brouwers JF, de Kroon AIPM. Yeast cells accumulate excess endogenous palmitate in phosphatidylcholine by acyl chain remodeling involving the phospholipase B Plb1p. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1167-76. [PMID: 23501167 DOI: 10.1016/j.bbalip.2013.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 03/01/2013] [Accepted: 03/04/2013] [Indexed: 11/18/2022]
Abstract
In the yeast Saccharomyces cerevisiae, the molecular species profile of the major membrane glycerophospholipid phosphatidylcholine (PC) is determined by the molecular species-selectivity of the biosynthesis routes and by acyl chain remodeling. Overexpression of the glycerol-3-phosphate acyltransferase Sct1p was recently shown to induce a strong increase in the cellular content of palmitate (C16:0). Using stable isotope labeling and mass spectrometry, the present study shows that wild type yeast overexpressing Sct1p incorporates excess C16:0 into PC via the methylation of PE, the CDP-choline route, and post-synthetic acyl chain remodeling. Overexpression of Sct1p increased the extent of remodeling of PE-derived PC, providing a novel tool to perform mechanistic studies on PC acyl chain exchange. The exchange of acyl chains occurred at both the sn-1 and sn-2 positions of the glycerol backbone of PC, and required the phospholipase B Plb1p for optimal efficiency. Sct1p-catalyzed acyl chain exchange, the acyl-CoA binding protein Acb1p, the Plb1p homologue Plb2p, and the glycerophospholipid:triacylglycerol transacylase Lro1p were not required for PC remodeling. The results indicate that PC serves as a buffer for excess cellular C16:0.
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13
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Dumas JF, Peyta L, Couet C, Servais S. Implication of liver cardiolipins in mitochondrial energy metabolism disorder in cancer cachexia. Biochimie 2012; 95:27-32. [PMID: 22819940 DOI: 10.1016/j.biochi.2012.07.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/10/2012] [Indexed: 11/17/2022]
Abstract
Mitochondrial membranes are essential for the good functioning of the organelle. For instance, the inner mitochondrial membrane contains the oxidative phosphorylation system that permits ATP synthesis. Phospholipids environment and especially cardiolipin are crucial for the mitochondrial energy metabolism. Indeed, cardiolipin is known to provide essential structural and functional support to several proteins involved in oxidative phosphorylation. Alterations in cardiolipin structure, content and fatty acids composition have been associated with mitochondrial dysfunction in several physiopathological conditions and diseases. Cancer cachexia is a complex and dynamic process characterized by a negative energy balance induced by anorexia and hypermetabolism which leads to a drastic loss in body weight that aggravate prognosis of cancer patients. The underlying mechanisms of hypermetabolism are not fully understood. Whether the mitochondrial energy metabolism is altered during this disease and may participate to hypermetabolism is not clear. This mini-review focuses on cardiolipin especially its biosynthesis and remodeling pathways, its relation with mitochondrial energy metabolism and its possible implication in the cancer cachexia syndrome.
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Abstract
Due to its genetic tractability and increasing wealth of accessible data, the yeast Saccharomyces cerevisiae is a model system of choice for the study of the genetics, biochemistry, and cell biology of eukaryotic lipid metabolism. Glycerolipids (e.g., phospholipids and triacylglycerol) and their precursors are synthesized and metabolized by enzymes associated with the cytosol and membranous organelles, including endoplasmic reticulum, mitochondria, and lipid droplets. Genetic and biochemical analyses have revealed that glycerolipids play important roles in cell signaling, membrane trafficking, and anchoring of membrane proteins in addition to membrane structure. The expression of glycerolipid enzymes is controlled by a variety of conditions including growth stage and nutrient availability. Much of this regulation occurs at the transcriptional level and involves the Ino2–Ino4 activation complex and the Opi1 repressor, which interacts with Ino2 to attenuate transcriptional activation of UASINO-containing glycerolipid biosynthetic genes. Cellular levels of phosphatidic acid, precursor to all membrane phospholipids and the storage lipid triacylglycerol, regulates transcription of UASINO-containing genes by tethering Opi1 to the nuclear/endoplasmic reticulum membrane and controlling its translocation into the nucleus, a mechanism largely controlled by inositol availability. The transcriptional activator Zap1 controls the expression of some phospholipid synthesis genes in response to zinc availability. Regulatory mechanisms also include control of catalytic activity of glycerolipid enzymes by water-soluble precursors, products and lipids, and covalent modification of phosphorylation, while in vivo function of some enzymes is governed by their subcellular location. Genome-wide genetic analysis indicates coordinate regulation between glycerolipid metabolism and a broad spectrum of metabolic pathways.
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Acyl coenzyme A thioesterase Them5/Acot15 is involved in cardiolipin remodeling and fatty liver development. Mol Cell Biol 2012; 32:2685-97. [PMID: 22586271 DOI: 10.1128/mcb.00312-12] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Acyl coenzyme A (acyl-CoA) thioesterases hydrolyze thioester bonds in acyl-CoA metabolites. The majority of mammalian thioesterases are α/β-hydrolases and have been studied extensively. A second class of Hotdog-fold enzymes has been less well described. Here, we present a structural and functional analysis of a new mammalian mitochondrial thioesterase, Them5. Them5 and its paralog, Them4, adopt the classical Hotdog-fold structure and form homodimers in crystals. In vitro, Them5 shows strong thioesterase activity with long-chain acyl-CoAs. Loss of Them5 specifically alters the remodeling process of the mitochondrial phospholipid cardiolipin. Them5(-/-) mice show deregulation of lipid metabolism and the development of fatty liver, exacerbated by a high-fat diet. Consequently, mitochondrial morphology is affected, and functions such as respiration and β-oxidation are impaired. The novel mitochondrial acyl-CoA thioesterase Them5 has a critical and specific role in the cardiolipin remodeling process, connecting it to the development of fatty liver and related conditions.
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Host acyl coenzyme A binding protein regulates replication complex assembly and activity of a positive-strand RNA virus. J Virol 2012; 86:5110-21. [PMID: 22345450 DOI: 10.1128/jvi.06701-11] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
All positive-strand RNA viruses reorganize host intracellular membranes to assemble their replication complexes. Similarly, brome mosaic virus (BMV) induces two alternate forms of membrane-bound RNA replication complexes: vesicular spherules and stacks of appressed double-membrane layers. The mechanisms by which these membrane rearrangements are induced, however, remain unclear. We report here that host ACB1-encoded acyl coenzyme A (acyl-CoA) binding protein (ACBP) is required for the assembly and activity of both BMV RNA replication complexes. ACBP is highly conserved among eukaryotes, specifically binds to long-chain fatty acyl-CoA, and promotes general lipid synthesis. Deleting ACB1 inhibited BMV RNA replication up to 30-fold and resulted in formation of spherules that were ∼50% smaller but ∼4-fold more abundant than those in wild-type (wt) cells, consistent with the idea that BMV 1a invaginates and maintains viral spherules by coating the inner spherule membrane. Furthermore, smaller and more frequent spherules were preferentially formed under conditions that induce layer formation in wt cells. Conversely, cellular karmella structures, which are arrays of endoplasmic reticulum (ER) membranes formed upon overexpression of certain cellular ER membrane proteins, were formed normally, indicating a selective inhibition of 1a-induced membrane rearrangements. Restoring altered lipid composition largely complemented the BMV RNA replication defect, suggesting that ACBP was required for maintaining lipid homeostasis. Smaller and more frequent spherules are also induced by 1a mutants with specific substitutions in a membrane-anchoring amphipathic α-helix, implying that the 1a-lipid interactions play critical roles in viral replication complex assembly.
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Abstract
Cardiolipin, the signature phospholipid of mitochondria, is a lipid dimer that is important for a diverse range of mitochondrial activities beyond the process of ATP production. Thus not surprisingly, derangements in cardiolipin metabolism are now appreciated to contribute to an assortment of pathological conditions. A comprehensive inventory of enzymes involved in cardiolipin biosynthesis and remodeling was just recently obtained. Post-biosynthesis, the acyl chain composition of cardiolipin is modified by up to three distinct remodeling enzymes that produce either a homogeneous tissue-specific mature form of cardiolipin or alternatively 'bad' cardiolipin that has been linked to mitochondrial dysfunction. In this review, we initially focus on the newly identified players in cardiolipin metabolism and then shift our attention to how changes in cardiolipin metabolism contribute to human disease.
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Claypool SM, Koehler CM. The complexity of cardiolipin in health and disease. Trends Biochem Sci 2011; 37:32-41. [PMID: 22014644 DOI: 10.1016/j.tibs.2011.09.003] [Citation(s) in RCA: 253] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 09/12/2011] [Accepted: 09/19/2011] [Indexed: 11/29/2022]
Abstract
Cardiolipin, the signature phospholipid of mitochondria, is a lipid dimer that is important for a diverse range of mitochondrial activities beyond the process of ATP production. Thus not surprisingly, derangements in cardiolipin metabolism are now appreciated to contribute to an assortment of pathological conditions. A comprehensive inventory of enzymes involved in cardiolipin biosynthesis and remodeling was just recently obtained. Post-biosynthesis, the acyl chain composition of cardiolipin is modified by up to three distinct remodeling enzymes that produce either a homogeneous tissue-specific mature form of cardiolipin or alternatively 'bad' cardiolipin that has been linked to mitochondrial dysfunction. In this review, we initially focus on the newly identified players in cardiolipin metabolism and then shift our attention to how changes in cardiolipin metabolism contribute to human disease.
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Affiliation(s)
- Steven M Claypool
- Department of Physiology, Johns Hopkins School of Medicine, Baltimore, MD 21205-2185, USA.
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Current awareness on yeast. Yeast 2010. [DOI: 10.1002/yea.1715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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The influence of the acyl chain composition of cardiolipin on the stability of mitochondrial complexes; An unexpected effect of cardiolipin in α-ketoglutarate dehydrogenase and prohibitin complexes. J Proteomics 2010; 73:806-14. [DOI: 10.1016/j.jprot.2009.11.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 11/02/2009] [Accepted: 11/17/2009] [Indexed: 02/06/2023]
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