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Briand-Mésange F, Gennero I, Salles J, Trudel S, Dahan L, Ausseil J, Payrastre B, Salles JP, Chap H. From Classical to Alternative Pathways of 2-Arachidonoylglycerol Synthesis: AlterAGs at the Crossroad of Endocannabinoid and Lysophospholipid Signaling. Molecules 2024; 29:3694. [PMID: 39125098 PMCID: PMC11314389 DOI: 10.3390/molecules29153694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 07/27/2024] [Accepted: 08/02/2024] [Indexed: 08/12/2024] Open
Abstract
2-arachidonoylglycerol (2-AG) is the most abundant endocannabinoid (EC), acting as a full agonist at both CB1 and CB2 cannabinoid receptors. It is synthesized on demand in postsynaptic membranes through the sequential action of phosphoinositide-specific phospholipase Cβ1 (PLCβ1) and diacylglycerol lipase α (DAGLα), contributing to retrograde signaling upon interaction with presynaptic CB1. However, 2-AG production might also involve various combinations of PLC and DAGL isoforms, as well as additional intracellular pathways implying other enzymes and substrates. Three other alternative pathways of 2-AG synthesis rest on the extracellular cleavage of 2-arachidonoyl-lysophospholipids by three different hydrolases: glycerophosphodiesterase 3 (GDE3), lipid phosphate phosphatases (LPPs), and two members of ecto-nucleotide pyrophosphatase/phosphodiesterases (ENPP6-7). We propose the names of AlterAG-1, -2, and -3 for three pathways sharing an ectocellular localization, allowing them to convert extracellular lysophospholipid mediators into 2-AG, thus inducing typical signaling switches between various G-protein-coupled receptors (GPCRs). This implies the critical importance of the regioisomerism of both lysophospholipid (LPLs) and 2-AG, which is the object of deep analysis within this review. The precise functional roles of AlterAGs are still poorly understood and will require gene invalidation approaches, knowing that both 2-AG and its related lysophospholipids are involved in numerous aspects of physiology and pathology, including cancer, inflammation, immune defenses, obesity, bone development, neurodegeneration, or psychiatric disorders.
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Affiliation(s)
- Fabienne Briand-Mésange
- Infinity-Toulouse Institute for Infectious and Inflammatory Diseases, University of Toulouse, INSERM, CNRS, Paul Sabatier University, 31059 Toulouse, France; (F.B.-M.); (I.G.); (J.S.); (S.T.); (J.A.); (J.-P.S.)
| | - Isabelle Gennero
- Infinity-Toulouse Institute for Infectious and Inflammatory Diseases, University of Toulouse, INSERM, CNRS, Paul Sabatier University, 31059 Toulouse, France; (F.B.-M.); (I.G.); (J.S.); (S.T.); (J.A.); (J.-P.S.)
- Centre Hospitalier Universitaire de Toulouse, Service de Biochimie, Institut Fédératif de Biologie, 31059 Toulouse, France
| | - Juliette Salles
- Infinity-Toulouse Institute for Infectious and Inflammatory Diseases, University of Toulouse, INSERM, CNRS, Paul Sabatier University, 31059 Toulouse, France; (F.B.-M.); (I.G.); (J.S.); (S.T.); (J.A.); (J.-P.S.)
- Centre Hospitalier Universitaire de Toulouse, Service de Psychiatrie D’urgences, de Crise et de Liaison, Institut des Handicaps Neurologiques, Psychiatriques et Sensoriels, 31059 Toulouse, France
| | - Stéphanie Trudel
- Infinity-Toulouse Institute for Infectious and Inflammatory Diseases, University of Toulouse, INSERM, CNRS, Paul Sabatier University, 31059 Toulouse, France; (F.B.-M.); (I.G.); (J.S.); (S.T.); (J.A.); (J.-P.S.)
- Centre Hospitalier Universitaire de Toulouse, Service de Biochimie, Institut Fédératif de Biologie, 31059 Toulouse, France
| | - Lionel Dahan
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France;
| | - Jérôme Ausseil
- Infinity-Toulouse Institute for Infectious and Inflammatory Diseases, University of Toulouse, INSERM, CNRS, Paul Sabatier University, 31059 Toulouse, France; (F.B.-M.); (I.G.); (J.S.); (S.T.); (J.A.); (J.-P.S.)
- Centre Hospitalier Universitaire de Toulouse, Service de Biochimie, Institut Fédératif de Biologie, 31059 Toulouse, France
| | - Bernard Payrastre
- I2MC-Institute of Metabolic and Cardiovascular Diseases, INSERM UMR1297 and University of Toulouse III, 31400 Toulouse, France;
- Centre Hospitalier Universitaire de Toulouse, Laboratoire d’Hématologie, 31400 Toulouse, France
| | - Jean-Pierre Salles
- Infinity-Toulouse Institute for Infectious and Inflammatory Diseases, University of Toulouse, INSERM, CNRS, Paul Sabatier University, 31059 Toulouse, France; (F.B.-M.); (I.G.); (J.S.); (S.T.); (J.A.); (J.-P.S.)
- Centre Hospitalier Universitaire de Toulouse, Unité d’Endocrinologie et Maladies Osseuses, Hôpital des Enfants, 31059 Toulouse, France
| | - Hugues Chap
- Infinity-Toulouse Institute for Infectious and Inflammatory Diseases, University of Toulouse, INSERM, CNRS, Paul Sabatier University, 31059 Toulouse, France; (F.B.-M.); (I.G.); (J.S.); (S.T.); (J.A.); (J.-P.S.)
- Académie des Sciences, Inscriptions et Belles Lettres de Toulouse, Hôtel d’Assézat, 31000 Toulouse, France
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Zhang P, Jiang H, Yang M, Bi C, Zhang K, Liu D, Wei M, Jiang Z, Lv K, Fang C, Liu J, Zhang T, Xu Y, Zhang J. AGK Potentiates Arterial Thrombosis by Affecting Talin-1 and αIIbβ3-Mediated Bidirectional Signaling Pathway. Arterioscler Thromb Vasc Biol 2023; 43:1015-1030. [PMID: 37051931 DOI: 10.1161/atvbaha.122.318647] [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: 03/15/2022] [Accepted: 03/22/2023] [Indexed: 04/14/2023]
Abstract
BACKGROUND AGK (acylglycerol kinase) was first identified as a mitochondrial transmembrane protein that exhibits a lipid kinase function. Recent studies have established that AGK promotes cancer growth and metastasis, enhances glycolytic metabolism and function fitness of CD8+ T cells, or regulates megakaryocyte differentiation. However, the role of AGK in platelet activation and arterial thrombosis remains to be elaborated. METHODS We performed hematologic analysis using automated hematology analyzer and investigated platelets morphology by transmission electron microscope. We explored the role of AGK in platelet activation and arterial thrombosis utilizing transgenic mice, platelet functional experiments in vitro, and thrombosis models in vivo. We revealed the regulation effect of AGK on Talin-1 by coimmunoprecipitation, mass spectrometry, immunofluorescence, and Western blot. We tested the role of AGK on lipid synthesis of phosphatidic acid/lysophosphatidic acid and thrombin generation by specific Elisa kits. RESULTS In this study, we found that AGK depletion or AGK mutation had no effect on the platelet average volumes, the platelet microstructures, or the expression levels of the major platelet membrane receptors. However, AGK deficiency or AGK mutation conspicuously decreased multiple aspects of platelet activation, including agonists-induced platelet aggregation, granules secretion, JON/A binding, spreading on Fg (fibrinogen), and clot retraction. AGK deficiency or AGK mutation also obviously delayed arterial thrombus formation but had no effect on tail bleeding time and platelet procoagulant function. Mechanistic investigation revealed that AGK may promote Talin-1Ser425 phosphorylation and affect the αIIbβ3-mediated bidirectional signaling pathway. However, AGK does not affect lipid synthesis of phosphatidic acid/lysophosphatidic acid in platelets. CONCLUSIONS AGK, through its kinase activity, potentiates platelet activation and arterial thrombosis by promoting Talin-1 Ser425 phosphorylation and affecting the αIIbβ3-mediated bidirectional signaling pathway.
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Affiliation(s)
- Peng Zhang
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China (P.Z., C.B., K.Z., D.L., M.W., Z.J., T.Z., J.Z.)
| | - Haojie Jiang
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, China (H.J., M.Y., J.L., Y.X.)
| | - Mina Yang
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, China (H.J., M.Y., J.L., Y.X.)
| | - Changlong Bi
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China (P.Z., C.B., K.Z., D.L., M.W., Z.J., T.Z., J.Z.)
| | - Kandi Zhang
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China (P.Z., C.B., K.Z., D.L., M.W., Z.J., T.Z., J.Z.)
| | - Dongsheng Liu
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China (P.Z., C.B., K.Z., D.L., M.W., Z.J., T.Z., J.Z.)
| | - Meng Wei
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China (P.Z., C.B., K.Z., D.L., M.W., Z.J., T.Z., J.Z.)
| | - Zheyi Jiang
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China (P.Z., C.B., K.Z., D.L., M.W., Z.J., T.Z., J.Z.)
| | - Keyu Lv
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, China (K.L., C.F.)
| | - Chao Fang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, China (K.L., C.F.)
| | - Junling Liu
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, China (H.J., M.Y., J.L., Y.X.)
| | - Tiantian Zhang
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China (P.Z., C.B., K.Z., D.L., M.W., Z.J., T.Z., J.Z.)
| | - Yanyan Xu
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, China (H.J., M.Y., J.L., Y.X.)
| | - Junfeng Zhang
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China (P.Z., C.B., K.Z., D.L., M.W., Z.J., T.Z., J.Z.)
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Busch JD, Fielden LF, Pfanner N, Wiedemann N. Mitochondrial protein transport: Versatility of translocases and mechanisms. Mol Cell 2023; 83:890-910. [PMID: 36931257 DOI: 10.1016/j.molcel.2023.02.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 03/17/2023]
Abstract
Biogenesis of mitochondria requires the import of approximately 1,000 different precursor proteins into and across the mitochondrial membranes. Mitochondria exhibit a wide variety of mechanisms and machineries for the translocation and sorting of precursor proteins. Five major import pathways that transport proteins to their functional intramitochondrial destination have been elucidated; these pathways range from the classical amino-terminal presequence-directed pathway to pathways using internal or even carboxy-terminal targeting signals in the precursors. Recent studies have provided important insights into the structural organization of membrane-embedded preprotein translocases of mitochondria. A comparison of the different translocases reveals the existence of at least three fundamentally different mechanisms: two-pore-translocase, β-barrel switching, and transport cavities open to the lipid bilayer. In addition, translocases are physically engaged in dynamic interactions with respiratory chain complexes, metabolite transporters, quality control factors, and machineries controlling membrane morphology. Thus, mitochondrial preprotein translocases are integrated into multi-functional networks of mitochondrial and cellular machineries.
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Affiliation(s)
- Jakob D Busch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Laura F Fielden
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
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Yamazaki A, Kawashima A, Honda T, Kohama T, Murakami C, Sakane F, Murayama T, Nakamura H. Identification and characterization of diacylglycerol kinase ζ as a novel enzyme producing ceramide-1-phosphate. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159307. [PMID: 36906254 DOI: 10.1016/j.bbalip.2023.159307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/16/2023] [Accepted: 03/01/2023] [Indexed: 03/13/2023]
Abstract
Ceramide-1-phosphate (C1P) is a sphingolipid formed by the phosphorylation of ceramide; it regulates various physiological functions, including cell survival, proliferation, and inflammatory responses. In mammals, ceramide kinase (CerK) is the only C1P-producing enzyme currently known. However, it has been suggested that C1P is also produced by a CerK-independent pathway, although the identity of this CerK-independent C1P was unknown. Here, we identified human diacylglycerol kinase (DGK) ζ as a novel C1P-producing enzyme and demonstrated that DGKζ catalyzes the phosphorylation of ceramide to produce C1P. Analysis using fluorescently labeled ceramide (NBD-ceramide) demonstrated that only DGKζ among ten kinds of DGK isoforms increased C1P production by transient overexpression of the DGK isoforms. Furthermore, an enzyme activity assay using purified DGKζ revealed that DGKζ could directly phosphorylate ceramide to produce C1P. Furthermore, genetic deletion of DGKζ decreased the formation of NBD-C1P and the levels of endogenous C18:1/24:1- and C18:1/26:0-C1P. Interestingly, the levels of endogenous C18:1/26:0-C1P were not decreased by the knockout of CerK in the cells. These results suggest that DGKζ is also involved in the formation of C1P under physiological conditions.
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Affiliation(s)
- Ayako Yamazaki
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Ayane Kawashima
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Takuya Honda
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Takafumi Kohama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Chiaki Murakami
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; Institute for Advanced Academic Research, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Fumio Sakane
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Toshihiko Murayama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Hiroyuki Nakamura
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
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A novel AGK splicing mutation in a patient with Sengers syndrome and left ventricular non-compaction cardiomyopathy. Pediatr Res 2023:10.1038/s41390-023-02515-3. [PMID: 36759750 DOI: 10.1038/s41390-023-02515-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/16/2022] [Accepted: 01/21/2023] [Indexed: 02/11/2023]
Abstract
BACKGROUND Sengers syndrome characterized by hypertrophic cardiomyopathy is an extremely rare genetic disorder. Sengers syndrome associated with left ventricular non-compaction (LVNC) has not been described. METHODS Genetic testing was used to identify candidate AGK variants in the proband. The predicted molecular structures were constructed by protein modeling. Exon skipping caused by the identified splicing mutations was verified by in silico analyses and in vitro assays. The genotypic and phenotypic features of patients with AGK splicing mutations were extracted by a systematic review. RESULTS The proband was characterized by Sengers syndrome and LVNC and caused by a novel compound heterozygous AGK splicing mutation. This compound mutation simultaneously perturbed the protein sequences and spatial conformation of the acylglycerol kinase protein. In silico and in vitro analyses demonstrated skipping of exons 7 and 8 and premature truncation as a result of exon 8 skipping. The systematic review indicated that patients with an AGK splicing mutation may have milder phenotypes of Sengers syndrome. CONCLUSIONS The genotypic and phenotypic spectrums of Sengers syndrome have been expanded, which will provide essential information for genetic counseling. The molecular mechanism in AGK mutations can offer insights into the potential targets for treatment. IMPACT First description of a child with Sengers syndrome and left ventricular non-compaction cardiomyopathy. A novel pathogenic compound heterozygous splicing mutation in AGK for Sengers syndrome was identified. The identified mutations led to exons skipping by in silico analyses and in vitro assays.
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The new progress in cancer immunotherapy. Clin Exp Med 2022:10.1007/s10238-022-00887-0. [DOI: 10.1007/s10238-022-00887-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/30/2022] [Indexed: 12/12/2022]
Abstract
AbstractThe cross talk between immune and non-immune cells in the tumor microenvironment leads to immunosuppression, which promotes tumor growth and survival. Immunotherapy is an advanced treatment that boosts humoral and cellular immunity rather than using chemotherapy or radiation-based strategy associated with non-specific targets and toxic effects on normal cells. Immune checkpoint inhibitors and T cell-based immunotherapy have already exhibited significant effects against solid tumors and leukemia. Tumor cells that escape immune surveillance create a major obstacle to acquiring an effective immune response in cancer patients. Tremendous progress had been made in recent years on a wide range of innate and adaptive immune checkpoints which play a significant role to prevent tumorigenesis, and might therefore be potential targets to suppress tumor cells growth. This review aimed to summarize the underlying molecular mechanisms of existing immunotherapy approaches including T cell and NK-derived immune checkpoint therapy, as well as other intrinsic and phagocytosis checkpoints. Together, these insights will pave the way for new innate and adaptive immunomodulatory targets for the development of highly effective new therapy in the future.
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Dudek J, Maack C. Mechano-energetic aspects of Barth syndrome. J Inherit Metab Dis 2022; 45:82-98. [PMID: 34423473 DOI: 10.1002/jimd.12427] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/28/2021] [Accepted: 08/19/2021] [Indexed: 12/22/2022]
Abstract
Energy-demanding organs like the heart are strongly dependent on oxidative phosphorylation in mitochondria. Oxidative phosphorylation is governed by the respiratory chain located in the inner mitochondrial membrane. The inner mitochondrial membrane is the only cellular membrane with significant amounts of the phospholipid cardiolipin, and cardiolipin was found to directly interact with a number of essential protein complexes, including respiratory chain complexes I to V. An inherited defect in the biogenesis of cardiolipin causes Barth syndrome, which is associated with cardiomyopathy, skeletal myopathy, neutropenia and growth retardation. Energy conversion is dependent on reducing equivalents, which are replenished by oxidative metabolism in the Krebs cycle. Cardiolipin deficiency in Barth syndrome also affects Krebs cycle activity, metabolite transport and mitochondrial morphology. During excitation-contraction coupling, calcium (Ca2+ ) released from the sarcoplasmic reticulum drives sarcomeric contraction. At the same time, Ca2+ influx into mitochondria drives the activation of Krebs cycle dehydrogenases and the regeneration of reducing equivalents. Reducing equivalents are essential not only for energy conversion, but also for maintaining a redox buffer, which is required to detoxify reactive oxygen species (ROS). Defects in CL may also affect Ca2+ uptake into mitochondria and thereby hamper energy supply and demand matching, but also detoxification of ROS. Here, we review the impact of cardiolipin deficiency on mitochondrial function in Barth syndrome and discuss potential therapeutic strategies.
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Affiliation(s)
- Jan Dudek
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
| | - Christoph Maack
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
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Che L, Xu M, Gao K, Wang L, Yang X, Wen X, Xiao H, Li M, Jiang Z. Mammary tissue proteomics in a pig model indicates that dietary valine supplementation increases milk fat content via increased de novo synthesis of fatty acid. Food Sci Nutr 2021; 9:6213-6223. [PMID: 34760251 PMCID: PMC8565212 DOI: 10.1002/fsn3.2574] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/03/2021] [Accepted: 08/28/2021] [Indexed: 12/14/2022] Open
Abstract
Milk fat is a major source of energy that determines the growth of neonates. Recently, studies have shown that valine is closely related to lipid metabolism. Therefore, this study was designed to investigate the effects of dietary valine supplementation on milk fat synthesis using a pig model. Thirty gilts were allotted to low (LV, total valine:lysine = 0.63:1), medium (MV, total valine:lysine = 0.73:1), and high (HV, total valine:lysine = 0.93:1) valine feeding levels from Day 75 of gestation till farrowing. The results demonstrated that the concentration of milk fat at Days 1, 3, and 7 of lactation in the HV group was higher than that in the MV and LV groups. The HV group had an increased (p < .05) proportion of total saturated and monounsaturated fatty acids than the other groups. Examination of mammary tissue proteomics in the HV and LV groups revealed 121 differentially expressed proteins (68 upregulated and 53 downregulated in the HV group). The upregulated proteins in the HV group were relevant to some crucial pathways related to milk fat synthesis, including fatty acid biosynthesis and metabolism, the AMPK signaling pathway, and oxidative phosphorylation. Furthermore, the key proteins involved in fatty acid synthesis (ACACA and FASN) were identified, and their expression levels were verified (p < .05) using Western blotting. Our findings revealed that dietary valine supplementation improves milk fat synthesis by modulating the expression of fatty acid synthesis-related proteins in mammary tissues.
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Affiliation(s)
- Long Che
- College of Animal Science and TechnologyHenan University of Animal Husbandry and EconomyZhengzhouChina
- State Key Laboratory of Livestock and Poultry BreedingKey Laboratory of Animal Nutrition and Feed Science in South ChinaMinistry of Agriculture, Guangdong Public Laboratory of Animal Breeding and NutritionGuangdong Key Laboratory of Animal Breeding and NutritionInstitute of Animal ScienceGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Mengmeng Xu
- College of Animal Science and TechnologyHenan University of Animal Husbandry and EconomyZhengzhouChina
- State Key Laboratory of Livestock and Poultry BreedingKey Laboratory of Animal Nutrition and Feed Science in South ChinaMinistry of Agriculture, Guangdong Public Laboratory of Animal Breeding and NutritionGuangdong Key Laboratory of Animal Breeding and NutritionInstitute of Animal ScienceGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Kaiguo Gao
- State Key Laboratory of Livestock and Poultry BreedingKey Laboratory of Animal Nutrition and Feed Science in South ChinaMinistry of Agriculture, Guangdong Public Laboratory of Animal Breeding and NutritionGuangdong Key Laboratory of Animal Breeding and NutritionInstitute of Animal ScienceGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Li Wang
- State Key Laboratory of Livestock and Poultry BreedingKey Laboratory of Animal Nutrition and Feed Science in South ChinaMinistry of Agriculture, Guangdong Public Laboratory of Animal Breeding and NutritionGuangdong Key Laboratory of Animal Breeding and NutritionInstitute of Animal ScienceGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Xuefen Yang
- State Key Laboratory of Livestock and Poultry BreedingKey Laboratory of Animal Nutrition and Feed Science in South ChinaMinistry of Agriculture, Guangdong Public Laboratory of Animal Breeding and NutritionGuangdong Key Laboratory of Animal Breeding and NutritionInstitute of Animal ScienceGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Xiaolu Wen
- State Key Laboratory of Livestock and Poultry BreedingKey Laboratory of Animal Nutrition and Feed Science in South ChinaMinistry of Agriculture, Guangdong Public Laboratory of Animal Breeding and NutritionGuangdong Key Laboratory of Animal Breeding and NutritionInstitute of Animal ScienceGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Hao Xiao
- State Key Laboratory of Livestock and Poultry BreedingKey Laboratory of Animal Nutrition and Feed Science in South ChinaMinistry of Agriculture, Guangdong Public Laboratory of Animal Breeding and NutritionGuangdong Key Laboratory of Animal Breeding and NutritionInstitute of Animal ScienceGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Mengyun Li
- College of Animal Science and TechnologyHenan University of Animal Husbandry and EconomyZhengzhouChina
| | - Zongyong Jiang
- State Key Laboratory of Livestock and Poultry BreedingKey Laboratory of Animal Nutrition and Feed Science in South ChinaMinistry of Agriculture, Guangdong Public Laboratory of Animal Breeding and NutritionGuangdong Key Laboratory of Animal Breeding and NutritionInstitute of Animal ScienceGuangdong Academy of Agricultural SciencesGuangzhouChina
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Wang H, Feng Z, Han X, Xing Y, Zhang X. Downregulation of acylglycerol kinase suppresses high glucose-induced endothelial-mesenchymal transition in HRECs through regulating the LPAR1/TGF-β/Notch signaling pathway. Can J Physiol Pharmacol 2021; 100:142-150. [PMID: 34559978 DOI: 10.1139/cjpp-2021-0265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The endothelial-mesenchymal transition (EndMT) participates in the progression of diabetic retinopathy (DR), but cell-intrinsic factors modulating this process remain elusive. In this study, we explored the role of lysophosphatidic acid (LPA)-producing enzyme, acylglycerol kinase (AGK) in the EndMT of human retinal microvascular endothelial cells (HRECs) under high glucose (HG) conditions. We found that AGK was significantly elevated in HG-treated cells. In addition, AGK knockdown reversed the HG-induced EndMT in HRECs, which was evidenced by the increased epithelial markers (CD31 and VE-cadherin) and decreased mesenchymal markers (FSP1 and α-SMA). Furthermore, downregulation of AGK inhibited the HG-induced activation of TGF-β/Notch pathways, whereas exogenous TGF-β1 (10 ng/ml) impeded the inhibitory effects of AGK knockdown on HG-induced EndMT in HRECs. Additionally, the silence of AGK abolished the HG-induced upregulation of LPA and its receptor LPAR1, and overexpression of LPAR1 further rescued the AGK knockdown-mediated inhibition of the EndMT process. In conclusion, we demonstrate that downregulation of acylglycerol kinase suppresses high glucose-induced endothelial-mesenchymal transition in HRECs through regulating the LPAR1/TGF-β/Notch signaling pathway, indicating that AGK might be a potential therapeutic target for the treatment of DR.
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Affiliation(s)
- Haijing Wang
- First Affiliated Hospital of Harbin Medical University, 74559, Harbin, Heilongjiang, China;
| | - Zhuolei Feng
- First Affiliated Hospital of Harbin Medical University, 74559, Harbin, Heilongjiang, China;
| | - Xue Han
- First Affiliated Hospital of Harbin Medical University, 74559, Harbin, Heilongjiang, China;
| | - Yue Xing
- First Affiliated Hospital of Harbin Medical University, 74559, Harbin, Heilongjiang, China;
| | - Xiaomei Zhang
- First Affiliated Hospital of Harbin Medical University, 74559, Harbin, Heilongjiang, China;
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Acoba MG, Senoo N, Claypool SM. Phospholipid ebb and flow makes mitochondria go. J Cell Biol 2021; 219:151918. [PMID: 32614384 PMCID: PMC7401802 DOI: 10.1083/jcb.202003131] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 01/19/2023] Open
Abstract
Mitochondria, so much more than just being energy factories, also have the capacity to synthesize macromolecules including phospholipids, particularly cardiolipin (CL) and phosphatidylethanolamine (PE). Phospholipids are vital constituents of mitochondrial membranes, impacting the plethora of functions performed by this organelle. Hence, the orchestrated movement of phospholipids to and from the mitochondrion is essential for cellular integrity. In this review, we capture recent advances in the field of mitochondrial phospholipid biosynthesis and trafficking, highlighting the significance of interorganellar communication, intramitochondrial contact sites, and lipid transfer proteins in maintaining membrane homeostasis. We then discuss the physiological functions of CL and PE, specifically how they associate with protein complexes in mitochondrial membranes to support bioenergetics and maintain mitochondrial architecture.
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Affiliation(s)
- Michelle Grace Acoba
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nanami Senoo
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
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11
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The role of AGK in thrombocytopoiesis and possible therapeutic strategies. Blood 2021; 136:119-129. [PMID: 32202634 DOI: 10.1182/blood.2019003851] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/03/2020] [Indexed: 12/11/2022] Open
Abstract
Abnormal megakaryocyte development and platelet production lead to thrombocytopenia or thrombocythemia and increase the risk of hemorrhage or thrombosis. Acylglycerol kinase (AGK) is a mitochondrial membrane kinase that catalyzes the formation of phosphatidic acid and lysophosphatidic acid. Mutation of AGK has been described as the major cause of Sengers syndrome, and the patients with Sengers syndrome have been reported to exhibit thrombocytopenia. In this study, we found that megakaryocyte/platelet-specific AGK-deficient mice developed thrombocytopenia and splenomegaly, mainly caused by inefficient bone marrow thrombocytopoiesis and excessive extramedullary hematopoiesis, but not by apoptosis of circulating platelets. It has been reported that the G126E mutation arrests the kinase activity of AGK. The AGK G126E mutation did not affect peripheral platelet counts or megakaryocyte differentiation, suggesting that the involvement of AGK in megakaryocyte development and platelet biogenesis was not dependent on its kinase activity. The Mpl/Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (Stat3) pathway is the major signaling pathway regulating megakaryocyte development. Our study confirmed that AGK can bind to JAK2 in megakaryocytes/platelets. More interestingly, we found that the JAK2 V617F mutation dramatically enhanced the binding of AGK to JAK2 and greatly facilitated JAK2/Stat3 signaling in megakaryocytes/platelets in response to thrombopoietin. We also found that the JAK2 JAK homology 2 domain peptide YGVCF617CGDENI enhanced the binding of AGK to JAK2 and that cell-permeable peptides containing YGVCF617CGDENI sequences accelerated proplatelet formation. Therefore, our study reveals critical roles of AGK in megakaryocyte differentiation and platelet biogenesis and suggests that targeting the interaction between AGK and JAK2 may be a novel strategy for the treatment of thrombocytopenia or thrombocythemia.
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12
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Li W, Zheng M, Zhao G, Wang J, Liu J, Wang S, Feng F, Liu D, Zhu D, Li Q, Guo L, Guo Y, Liu R, Wen J. Identification of QTL regions and candidate genes for growth and feed efficiency in broilers. Genet Sel Evol 2021; 53:13. [PMID: 33549052 PMCID: PMC7866652 DOI: 10.1186/s12711-021-00608-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 01/26/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Feed accounts for about 70% of the total cost of poultry meat production. Residual feed intake (RFI) has become the preferred measure of feed efficiency because it is phenotypically independent of growth rate and body weight. In this study, our aim was to estimate genetic parameters and identify quantitative trait loci (QTL) for feed efficiency in 3314 purebred broilers using a genome-wide association study. Broilers were genotyped using a custom 55 K single nucleotide polymorphism (SNP) array. RESULTS Estimates of genomic heritability for seven growth and feed efficiency traits, including body weight at 28 days of age (BW28), BW42, average daily feed intake (ADFI), RFI, and RFI adjusted for weight of abdominal fat (RFIa), ranged from 0.12 to 0.26. Eleven genome-wide significant SNPs and 15 suggestively significant SNPs were detected, of which 19 clustered around two genomic regions. A region on chromosome 16 (2.34-2.66 Mb) was associated with both BW28 and BW42, and the most significant SNP in this region, AX_101003762, accounted for 7.6% of the genetic variance of BW28. The other region, on chromosome 1 (91.27-92.43 Mb) was associated with RFI and ADFI, and contains the NSUN3 and EPHA6 as candidate genes. The most significant SNP in this region, AX_172588157, accounted for 4.4% of the genetic variance of RFI. In addition, a genomic region containing the gene AGK on chromosome 1 was found to be associated with RFIa. The NSUN3 and AGK genes were found to be differentially expressed in breast muscle, thigh muscle, and abdominal fat between male broilers with high and low RFI. CONCLUSIONS We identified QTL regions for BW28 and BW42 (spanning 0.32 Mb) and RFI (spanning 1.16 Mb). The NSUN3, EPHA6, and AGK were identified as the most likely candidate genes for these QTL. These genes are involved in mitochondrial function and behavioral regulation. These results contribute to the identification of candidate genes and variants for growth and feed efficiency in poultry.
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Affiliation(s)
- Wei Li
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
- College of Animal Science and Technology, China Agricultural University, Beijing, 100193 China
| | - Maiqing Zheng
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Guiping Zhao
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Jie Wang
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Jie Liu
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Shunli Wang
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Furong Feng
- Foshan Gaoming Xinguang Agricultural and Animal Industrials Corporation, Foshan, 528515 China
| | - Dawei Liu
- Foshan Gaoming Xinguang Agricultural and Animal Industrials Corporation, Foshan, 528515 China
| | - Dan Zhu
- Foshan Gaoming Xinguang Agricultural and Animal Industrials Corporation, Foshan, 528515 China
| | - Qinghe Li
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Liping Guo
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
- College of Animal Science and Technology, China Agricultural University, Beijing, 100193 China
| | - Yuming Guo
- College of Animal Science and Technology, China Agricultural University, Beijing, 100193 China
| | - Ranran Liu
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
| | - Jie Wen
- State Key Laboratory of Animal Nutrition; Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193 China
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13
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Jackson TD, Hock DH, Fujihara KM, Palmer CS, Frazier AE, Low YC, Kang Y, Ang CS, Clemons NJ, Thorburn DR, Stroud DA, Stojanovski D. The TIM22 complex mediates the import of sideroflexins and is required for efficient mitochondrial one-carbon metabolism. Mol Biol Cell 2021; 32:475-491. [PMID: 33476211 PMCID: PMC8101445 DOI: 10.1091/mbc.e20-06-0390] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Acylglycerol kinase (AGK) is a mitochondrial lipid kinase that contributes to protein biogenesis as a subunit of the TIM22 complex at the inner mitochondrial membrane. Mutations in AGK cause Sengers syndrome, an autosomal recessive condition characterized by congenital cataracts, hypertrophic cardiomyopathy, skeletal myopathy, and lactic acidosis. We mapped the proteomic changes in Sengers patient fibroblasts and AGKKO cell lines to understand the effects of AGK dysfunction on mitochondria. This uncovered down-regulation of a number of proteins at the inner mitochondrial membrane, including many SLC25 carrier family proteins, which are predicted substrates of the complex. We also observed down-regulation of SFXN proteins, which contain five transmembrane domains, and show that they represent a novel class of TIM22 complex substrate. Perturbed biogenesis of SFXN proteins in cells lacking AGK reduces the proliferative capabilities of these cells in the absence of exogenous serine, suggesting that dysregulation of one-carbon metabolism is a molecular feature in the biology of Sengers syndrome.
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Affiliation(s)
- Thomas D Jackson
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Daniella H Hock
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Kenji M Fujihara
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria 3010, Australia.,Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Catherine S Palmer
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Ann E Frazier
- Murdoch Children's Research Institute and.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Yau C Low
- Murdoch Children's Research Institute and.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Yilin Kang
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Ching-Seng Ang
- Bio21 Mass Spectrometry and Proteomics Facility, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Nicholas J Clemons
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria 3010, Australia.,Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - David R Thorburn
- Murdoch Children's Research Institute and.,Victorian Clinical Genetics Services Royal Children's Hospital, Melbourne, Victoria 3052, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - David A Stroud
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Diana Stojanovski
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
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14
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Muñoz-Gómez SA, Snyder SN, Montoya SJ, Wideman JG. Independent accretion of TIM22 complex subunits in the animal and fungal lineages. F1000Res 2020; 9:1060. [PMID: 33014348 PMCID: PMC7523481 DOI: 10.12688/f1000research.25904.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/21/2020] [Indexed: 12/25/2022] Open
Abstract
Background: The mitochondrial protein import complexes arose early in eukaryogenesis. Most of the components of the protein import pathways predate the last eukaryotic common ancestor. For example, the carrier-insertase TIM22 complex comprises the widely conserved Tim22 channel core. However, the auxiliary components of fungal and animal TIM22 complexes are exceptions to this ancient conservation. Methods: Using comparative genomics and phylogenetic approaches, we identified precisely when each TIM22 accretion occurred. Results: In animals, we demonstrate that Tim29 and Tim10b arose early in the holozoan lineage. Tim29 predates the metazoan lineage being present in the animal sister lineages, choanoflagellate and filastereans, whereas the erroneously named Tim10b arose from a duplication of Tim9 at the base of metazoans. In fungi, we show that Tim54 has representatives present in every holomycotan lineage including microsporidians and fonticulids, whereas Tim18 and Tim12 appeared much later in fungal evolution. Specifically, Tim18 and Tim12 arose from duplications of Sdh3 and Tim10, respectively, early in the Saccharomycotina. Surprisingly, we show that Tim54 is distantly related to AGK suggesting that AGK and Tim54 are extremely divergent orthologues and the origin of AGK/Tim54 interaction with Tim22 predates the divergence of animals and fungi. Conclusions: We argue that the evolutionary history of the TIM22 complex is best understood as the neutral structural divergence of an otherwise strongly functionally conserved protein complex. This view suggests that many of the differences in structure/subunit composition of multi-protein complexes are non-adaptive. Instead, most of the phylogenetic variation of functionally conserved molecular machines, which have been under stable selective pressures for vast phylogenetic spans, such as the TIM22 complex, is most likely the outcome of the interplay of random genetic drift and mutation pressure.
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Affiliation(s)
- Sergio A. Muñoz-Gómez
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Shannon N. Snyder
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Samantha J. Montoya
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Jeremy G. Wideman
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
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15
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Bertero E, Kutschka I, Maack C, Dudek J. Cardiolipin remodeling in Barth syndrome and other hereditary cardiomyopathies. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165803. [PMID: 32348916 DOI: 10.1016/j.bbadis.2020.165803] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/19/2019] [Accepted: 04/13/2020] [Indexed: 12/18/2022]
Abstract
Mitochondria play a prominent role in cardiac energy metabolism, and their function is critically dependent on the integrity of mitochondrial membranes. Disorders characterized by mitochondrial dysfunction are commonly associated with cardiac disease. The mitochondrial phospholipid cardiolipin directly interacts with a number of essential protein complexes in the mitochondrial membranes including the respiratory chain, mitochondrial metabolite carriers, and proteins critical for mitochondrial morphology. Barth syndrome is an X-linked disorder caused by an inherited defect in the biogenesis of the mitochondrial phospholipid cardiolipin. How cardiolipin deficiency impacts on mitochondrial function and how mitochondrial dysfunction causes cardiomyopathy has been intensively studied in cellular and animal models of Barth syndrome. These findings may also have implications for the molecular mechanisms underlying other inherited disorders associated with defects in cardiolipin, such as Sengers syndrome and dilated cardiomyopathy with ataxia (DCMA).
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Affiliation(s)
- Edoardo Bertero
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, 97078 Würzburg, Germany
| | - Ilona Kutschka
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, 97078 Würzburg, Germany
| | - Christoph Maack
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, 97078 Würzburg, Germany
| | - Jan Dudek
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, 97078 Würzburg, Germany.
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16
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Odendall F, Backes S, Tatsuta T, Weill U, Schuldiner M, Langer T, Herrmann JM, Rapaport D, Dimmer KS. The mitochondrial intermembrane space-facing proteins Mcp2 and Tgl2 are involved in yeast lipid metabolism. Mol Biol Cell 2019; 30:2681-2694. [PMID: 31483742 PMCID: PMC6761770 DOI: 10.1091/mbc.e19-03-0166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondria are unique organelles harboring two distinct membranes, the mitochondrial inner and outer membrane (MIM and MOM, respectively). Mitochondria comprise only a subset of metabolic pathways for the synthesis of membrane lipids; therefore most lipid species and their precursors have to be imported from other cellular compartments. One such import process is mediated by the ER mitochondria encounter structure (ERMES) complex. Both mitochondrial membranes surround the hydrophilic intermembrane space (IMS). Therefore, additional systems are required that shuttle lipids between the MIM and MOM. Recently, we identified the IMS protein Mcp2 as a high-copy suppressor for cells that lack a functional ERMES complex. To understand better how mitochondria facilitate transport and biogenesis of lipids, we searched for genetic interactions of this suppressor. We found that MCP2 has a negative genetic interaction with the gene TGL2 encoding a neutral lipid hydrolase. We show that this lipase is located in the intermembrane space of the mitochondrion and is imported via the Mia40 disulfide relay system. Furthermore, we show a positive genetic interaction of double deletion of MCP2 and PSD1, the gene encoding the enzyme that synthesizes the major amount of cellular phosphatidylethanolamine. Finally, we demonstrate that the nucleotide-binding motifs of the predicted atypical kinase Mcp2 are required for its proper function. Taken together, our data suggest that Mcp2 is involved in mitochondrial lipid metabolism and an increase of this involvement by overexpression suppresses loss of ERMES.
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Affiliation(s)
- Fenja Odendall
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Sandra Backes
- Cell Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Takashi Tatsuta
- Max Planck Institute for Biology of Ageing, 50931 Köln, Germany
| | - Uri Weill
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Thomas Langer
- Max Planck Institute for Biology of Ageing, 50931 Köln, Germany
| | | | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Kai Stefan Dimmer
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
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17
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Hu Z, Qu G, Yu X, Jiang H, Teng XL, Ding L, Hu Q, Guo X, Zhou Y, Wang F, Li HB, Chen L, Jiang J, Su B, Liu J, Zou Q. Acylglycerol Kinase Maintains Metabolic State and Immune Responses of CD8 + T Cells. Cell Metab 2019; 30:290-302.e5. [PMID: 31204281 DOI: 10.1016/j.cmet.2019.05.016] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/23/2019] [Accepted: 05/17/2019] [Indexed: 12/21/2022]
Abstract
CD8+ T cell expansions and functions rely on glycolysis, but the mechanisms underlying CD8+ T cell glycolytic metabolism remain elusive. Here, we show that acylglycerol kinase (AGK) is required for the establishment and maintenance of CD8+ T cell metabolic and functional fitness. AGK deficiency dampens CD8+ T cell antitumor functions in vivo and perturbs CD8+ T cell proliferation in vitro. Activation of phosphatidylinositol-3-OH kinase (PI3K)-mammalian target of rapamycin (mTOR) signaling, which mediates elevated CD8+ T cell glycolysis, is tightly dependent on AGK kinase activity. Mechanistically, T cell antigen receptor (TCR)- and CD28-stimulated recruitment of PTEN to the plasma membrane facilitates AGK-PTEN interaction and AGK-triggered PTEN phosphorylation, thereby restricting PTEN phosphatase activity in CD8+ T cells. Collectively, these results demonstrate that AGK maintains CD8+ T cell metabolic and functional state by restraining PTEN activity and highlight a critical role for AGK in CD8+ T cell metabolic programming and effector function.
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Affiliation(s)
- Zhilin Hu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Guojun Qu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Xiaoyan Yu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Haojie Jiang
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Xiao-Lu Teng
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Lei Ding
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Qianwen Hu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Xinwei Guo
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Yan Zhou
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Feng Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Hua-Bing Li
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Lei Chen
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China
| | - Jin Jiang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China.
| | - Junling Liu
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China.
| | - Qiang Zou
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China.
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18
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Mitochondrial diseases caused by dysfunctional mitochondrial protein import. Biochem Soc Trans 2018; 46:1225-1238. [PMID: 30287509 DOI: 10.1042/bst20180239] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/20/2018] [Accepted: 08/31/2018] [Indexed: 12/18/2022]
Abstract
Mitochondria are essential organelles which perform complex and varied functions within eukaryotic cells. Maintenance of mitochondrial health and functionality is thus a key cellular priority and relies on the organelle's extensive proteome. The mitochondrial proteome is largely encoded by nuclear genes, and mitochondrial proteins must be sorted to the correct mitochondrial sub-compartment post-translationally. This essential process is carried out by multimeric and dynamic translocation and sorting machineries, which can be found in all four mitochondrial compartments. Interestingly, advances in the diagnosis of genetic disease have revealed that mutations in various components of the human import machinery can cause mitochondrial disease, a heterogenous and often severe collection of disorders associated with energy generation defects and a multisystem presentation often affecting the cardiovascular and nervous systems. Here, we review our current understanding of mitochondrial protein import systems in human cells and the molecular basis of mitochondrial diseases caused by defects in these pathways.
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19
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Dudek J, Hartmann M, Rehling P. The role of mitochondrial cardiolipin in heart function and its implication in cardiac disease. Biochim Biophys Acta Mol Basis Dis 2018; 1865:810-821. [PMID: 30837070 DOI: 10.1016/j.bbadis.2018.08.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/14/2018] [Accepted: 08/17/2018] [Indexed: 01/21/2023]
Abstract
Mitochondria play an essential role in the energy metabolism of the heart. Many of the essential functions are associated with mitochondrial membranes and oxidative phosphorylation driven by the respiratory chain. Mitochondrial membranes are unique in the cell as they contain the phospholipid cardiolipin. The important role of cardiolipin in cardiovascular health is highlighted by several cardiac diseases, in which cardiolipin plays a fundamental role. Barth syndrome, Sengers syndrome, and Dilated cardiomyopathy with ataxia (DCMA) are genetic disorders, which affect cardiolipin biosynthesis. Other cardiovascular diseases including ischemia/reperfusion injury and heart failure are also associated with changes in the cardiolipin pool. Here, we summarize molecular functions of cardiolipin in mitochondrial biogenesis and morphology. We highlight the role of cardiolipin for the respiratory chain, metabolite carriers, and mitochondrial metabolism and describe links to apoptosis and mitochondria specific autophagy (mitophagy) with possible implications in cardiac disease.
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Affiliation(s)
- Jan Dudek
- Institute of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany
| | - Magnus Hartmann
- Institute of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany
| | - Peter Rehling
- Institute of Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany; Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany.
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20
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Allali S, Dorboz I, Samaan S, Slama A, Rambaud C, Boespflug-Tanguy O, Sarret C. Mutation in the AGK gene in two siblings with unusual Sengers syndrome. Metab Brain Dis 2017; 32:2149-2154. [PMID: 28868593 DOI: 10.1007/s11011-017-0101-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 08/21/2017] [Indexed: 12/14/2022]
Abstract
Sengers syndrome is a rare autosomal recessive metabolic disorder caused by lack of acylglycerol kinase due to mutations in the AGK gene. It is characterized by congenital cataract, hypertrophic cardiomyopathy, myopathy and lactic acidosis. Two clinical forms have been described: a severe neonatal form, and a more benign form displaying exercise intolerance. We describe two siblings with congenital cataract, cardiomyopathy, hypotonia, intellectual disability and lactic acidosis. Whole exome sequencing revealed a homozygous c.1035dup mutation in the two siblings, supporting a diagnosis of Sengers syndrome. Our patients presented an intermediate form with intellectual deficiency, an unusual feature in Sengers syndrome. This permitted a prenatal diagnosis for a following pregnancy.
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Affiliation(s)
- Sanae Allali
- Service des Urgences Pédiatriques, Hôpital Estaing, Centre Hospitalier Universitaire de Clermont-Ferrand, Clermont-Ferrand, France
| | - Imen Dorboz
- Inserm U1141 Paris Diderot Sorbonne Université-Paris Cité, DHU PROTECT, Hôpital Robert Debré, Paris, France
| | - Simon Samaan
- Département de Génétique, Hôpital Robert Debré, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Abdelhamid Slama
- pôle BPP-SP, Hôpital de Bicêtre, Assistance Publique - Hôpitaux de Paris, Le Kremlin-Bicêtre, France
| | - Charlène Rambaud
- Service de Génétique Médicale, Hôpital Estaing, Centre Hospitalier Universitaire de Clermont-Ferrand, Clermont-Ferrand, France
| | - Odile Boespflug-Tanguy
- Inserm U1141 Paris Diderot Sorbonne Université-Paris Cité, DHU PROTECT, Hôpital Robert Debré, Paris, France
| | - Catherine Sarret
- Service de Génétique Médicale, Hôpital Estaing, Centre Hospitalier Universitaire de Clermont-Ferrand, Clermont-Ferrand, France.
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21
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Towbin JA, Jefferies JL. Cardiomyopathies Due to Left Ventricular Noncompaction, Mitochondrial and Storage Diseases, and Inborn Errors of Metabolism. Circ Res 2017; 121:838-854. [PMID: 28912186 DOI: 10.1161/circresaha.117.310987] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The normal function of the human myocardium requires the proper generation and utilization of energy and relies on a series of complex metabolic processes to achieve this normal function. When metabolic processes fail to work properly or effectively, heart muscle dysfunction can occur with or without accompanying functional abnormalities of other organ systems, particularly skeletal muscle. These metabolic derangements can result in structural, functional, and infiltrative deficiencies of the heart muscle. Mitochondrial and enzyme defects predominate as disease-related etiologies. In this review, left ventricular noncompaction cardiomyopathy, which is often caused by mutations in sarcomere and cytoskeletal proteins and is also associated with metabolic abnormalities, is discussed. In addition, cardiomyopathies resulting from mitochondrial dysfunction, metabolic abnormalities, storage diseases, and inborn errors of metabolism are described.
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Affiliation(s)
- Jeffrey A Towbin
- From the Le Bonheur Children's Hospital, St Jude Children's Research Hospital, University of Tennessee Health Science Center, Memphis; and Cincinnati Children's Hospital Medical Center, University of Cincinnati, OH.
| | - John Lynn Jefferies
- From the Le Bonheur Children's Hospital, St Jude Children's Research Hospital, University of Tennessee Health Science Center, Memphis; and Cincinnati Children's Hospital Medical Center, University of Cincinnati, OH
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22
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Dudek J. Role of Cardiolipin in Mitochondrial Signaling Pathways. Front Cell Dev Biol 2017; 5:90. [PMID: 29034233 PMCID: PMC5626828 DOI: 10.3389/fcell.2017.00090] [Citation(s) in RCA: 254] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 09/21/2017] [Indexed: 02/06/2023] Open
Abstract
The phospholipid cardiolipin (CL) is an essential constituent of mitochondrial membranes and plays a role in many mitochondrial processes, including respiration and energy conversion. Pathological changes in CL amount or species composition can have deleterious consequences for mitochondrial function and trigger the production of reactive oxygen species. Signaling networks monitor mitochondrial function and trigger an adequate cellular response. Here, we summarize the role of CL in cellular signaling pathways and focus on tissues with high-energy demand, like the heart. CL itself was recently identified as a precursor for the formation of lipid mediators. We highlight the concept of CL as a signaling platform. CL is exposed to the outer mitochondrial membrane upon mitochondrial stress and CL domains serve as a binding site in many cellular signaling events. During mitophagy, CL interacts with essential players of mitophagy like Beclin 1 and recruits the autophagic machinery by its interaction with LC3. Apoptotic signaling pathways require CL as a binding platform to recruit apoptotic factors such as tBid, Bax, caspase-8. CL required for the activation of the inflammasome and plays a role in inflammatory signaling. As changes in CL species composition has been observed in many diseases, the signaling pathways described here may play a general role in pathology.
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Affiliation(s)
- Jan Dudek
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
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23
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Vukotic M, Nolte H, König T, Saita S, Ananjew M, Krüger M, Tatsuta T, Langer T. Acylglycerol Kinase Mutated in Sengers Syndrome Is a Subunit of the TIM22 Protein Translocase in Mitochondria. Mol Cell 2017; 67:471-483.e7. [DOI: 10.1016/j.molcel.2017.06.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/13/2017] [Accepted: 06/13/2017] [Indexed: 11/15/2022]
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Sengers Syndrome-Associated Mitochondrial Acylglycerol Kinase Is a Subunit of the Human TIM22 Protein Import Complex. Mol Cell 2017; 67:457-470.e5. [DOI: 10.1016/j.molcel.2017.06.014] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/28/2017] [Accepted: 06/13/2017] [Indexed: 11/19/2022]
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25
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Intramitochondrial phospholipid trafficking. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:81-89. [PMID: 27542541 DOI: 10.1016/j.bbalip.2016.08.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/03/2016] [Accepted: 08/11/2016] [Indexed: 12/29/2022]
Abstract
Mitochondrial functions and architecture rely on a defined lipid composition of their outer and inner membranes, which are characterized by a high content of non-bilayer phospholipids such as cardiolipin (CL) and phosphatidylethanolamine (PE). Mitochondrial membrane lipids are synthesized in the endoplasmic reticulum (ER) or within mitochondria from ER-derived precursor lipids, are asymmetrically distributed within mitochondria and can relocate in response to cellular stress. Maintenance of lipid homeostasis thus requires multiple lipid transport processes to be orchestrated within mitochondria. Recent findings identified members of the Ups/PRELI family as specific lipid transfer proteins in mitochondria that shuttle phospholipids between mitochondrial membranes. They cooperate with membrane organizing proteins that preserve the spatial organization of mitochondrial membranes and the formation of membrane contact sites, unravelling an intimate crosstalk of membrane lipid transport and homeostasis with the structural organization of mitochondria. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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26
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Sphingosine Kinases: Emerging Structure-Function Insights. Trends Biochem Sci 2016; 41:395-409. [PMID: 27021309 DOI: 10.1016/j.tibs.2016.02.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/08/2016] [Accepted: 02/17/2016] [Indexed: 12/15/2022]
Abstract
Sphingosine kinases (SK1 and SK2) catalyse the conversion of sphingosine into sphingosine 1-phosphate and control fundamental cellular processes, including cell survival, proliferation, differentiation, migration, and immune function. In this review, we highlight recent breakthroughs in the structural and functional characterisation of SK1 and these are contextualised by analysis of crystal structures for closely related prokaryotic lipid kinases. We identify a putative dimerisation interface and propose novel regulatory mechanisms governing structural plasticity induced by phosphorylation and interaction with phospholipids and proteins. Our analysis suggests that the catalytic function and regulation of the enzymes might be dependent on conformational mobility and it provides a roadmap for future interrogation of SK1 function and its role in physiology and disease.
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27
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Zhou YY, Ji XF, Fu JP, Zhu XJ, Li RH, Mu CK, Wang CL, Song WW. Gene Transcriptional and Metabolic Profile Changes in Mimetic Aging Mice Induced by D-Galactose. PLoS One 2015; 10:e0132088. [PMID: 26176541 PMCID: PMC4503422 DOI: 10.1371/journal.pone.0132088] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 06/10/2015] [Indexed: 01/09/2023] Open
Abstract
D-galactose injection has been shown to induce many changes in mice that represent accelerated aging. This mouse model has been widely used for pharmacological studies of anti-aging agents. The underlying mechanism of D-galactose induced aging remains unclear, however, it appears to relate to glucose and 1ipid metabolic disorders. Currently, there has yet to be a study that focuses on investigating gene expression changes in D-galactose aging mice. In this study, integrated analysis of gas chromatography/mass spectrometry-based metabonomics and gene expression profiles was used to investigate the changes in transcriptional and metabolic profiles in mimetic aging mice injected with D-galactose. Our findings demonstrated that 48 mRNAs were differentially expressed between control and D-galactose mice, and 51 potential biomarkers were identified at the metabolic level. The effects of D-galactose on aging could be attributed to glucose and 1ipid metabolic disorders, oxidative damage, accumulation of advanced glycation end products (AGEs), reduction in abnormal substance elimination, cell apoptosis, and insulin resistance.
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Affiliation(s)
- Yue-Yue Zhou
- Key Laboratory of the Ministry of Education for Applied Marine Biotechnology, Ningbo University, Ningbo, China
- Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
| | - Xiong-Fei Ji
- Key Laboratory of the Ministry of Education for Applied Marine Biotechnology, Ningbo University, Ningbo, China
- Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
| | - Jian-Ping Fu
- Key Laboratory of the Ministry of Education for Applied Marine Biotechnology, Ningbo University, Ningbo, China
- Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
| | - Xiao-Juan Zhu
- Key Laboratory of the Ministry of Education for Applied Marine Biotechnology, Ningbo University, Ningbo, China
- Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
| | - Rong-Hua Li
- Key Laboratory of the Ministry of Education for Applied Marine Biotechnology, Ningbo University, Ningbo, China
- Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
| | - Chang-Kao Mu
- Key Laboratory of the Ministry of Education for Applied Marine Biotechnology, Ningbo University, Ningbo, China
- Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
| | - Chun-Lin Wang
- Key Laboratory of the Ministry of Education for Applied Marine Biotechnology, Ningbo University, Ningbo, China
- Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
- * E-mail: (WWS); (CLW)
| | - Wei-Wei Song
- Key Laboratory of the Ministry of Education for Applied Marine Biotechnology, Ningbo University, Ningbo, China
- Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo University, Ningbo, China
- * E-mail: (WWS); (CLW)
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Lu YW, Claypool SM. Disorders of phospholipid metabolism: an emerging class of mitochondrial disease due to defects in nuclear genes. Front Genet 2015; 6:3. [PMID: 25691889 PMCID: PMC4315098 DOI: 10.3389/fgene.2015.00003] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 01/06/2015] [Indexed: 01/14/2023] Open
Abstract
The human nuclear and mitochondrial genomes co-exist within each cell. While the mitochondrial genome encodes for a limited number of proteins, transfer RNAs, and ribosomal RNAs, the vast majority of mitochondrial proteins are encoded in the nuclear genome. Of the multitude of mitochondrial disorders known to date, only a fifth are maternally inherited. The recent characterization of the mitochondrial proteome therefore serves as an important step toward delineating the nosology of a large spectrum of phenotypically heterogeneous diseases. Following the identification of the first nuclear gene defect to underlie a mitochondrial disorder, a plenitude of genetic variants that provoke mitochondrial pathophysiology have been molecularly elucidated and classified into six categories that impact: (1) oxidative phosphorylation (subunits and assembly factors); (2) mitochondrial DNA maintenance and expression; (3) mitochondrial protein import and assembly; (4) mitochondrial quality control (chaperones and proteases); (5) iron–sulfur cluster homeostasis; and (6) mitochondrial dynamics (fission and fusion). Here, we propose that an additional class of genetic variant be included in the classification schema to acknowledge the role of genetic defects in phospholipid biosynthesis, remodeling, and metabolism in mitochondrial pathophysiology. This seventh class includes a small but notable group of nuclear-encoded proteins whose dysfunction impacts normal mitochondrial phospholipid metabolism. The resulting human disorders present with a diverse array of pathologic consequences that reflect the variety of functions that phospholipids have in mitochondria and highlight the important role of proper membrane homeostasis in mitochondrial biology.
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Affiliation(s)
- Ya-Wen Lu
- Department of Physiology, School of Medicine, Johns Hopkins University Baltimore, MD, USA
| | - Steven M Claypool
- Department of Physiology, School of Medicine, Johns Hopkins University Baltimore, MD, USA
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29
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Mayr JA. Lipid metabolism in mitochondrial membranes. J Inherit Metab Dis 2015; 38:137-44. [PMID: 25082432 DOI: 10.1007/s10545-014-9748-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 07/10/2014] [Accepted: 07/15/2014] [Indexed: 12/26/2022]
Abstract
Mitochondrial membranes have a unique lipid composition necessary for proper shape and function of the organelle. Mitochondrial lipid metabolism involves biosynthesis of the phospholipids phosphatidylethanolamine, cardiolipin and phosphatidylglycerol, the latter is a precursor of the late endosomal lipid bis(monoacylglycero)phosphate. It also includes mitochondrial fatty acid synthesis necessary for the formation of the lipid cofactor lipoic acid. Furthermore the synthesis of coenzyme Q takes place in mitochondria as well as essential parts of the steroid and vitamin D metabolism. Lipid transport and remodelling, which are necessary for tailoring and maintaining specific membrane properties, are just partially unravelled. Mitochondrial lipids are involved in organelle maintenance, fission and fusion, mitophagy and cytochrome c-mediated apoptosis. Mutations in TAZ, SERAC1 and AGK affect mitochondrial phospholipid metabolism and cause Barth syndrome, MEGDEL and Sengers syndrome, respectively. In these disorders an abnormal mitochondrial energy metabolism was found, which seems to be due to disturbed protein-lipid interactions, affecting especially enzymes of the oxidative phosphorylation. Since a growing number of enzymes and transport processes are recognised as parts of the mitochondrial lipid metabolism, a further increase of lipid-related disorders can be expected.
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Affiliation(s)
- Johannes A Mayr
- Department of Paediatrics, Paracelsus Medical University Salzburg, Salzburg, 5020, Austria,
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30
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Haghighi A, Haack TB, Atiq M, Mottaghi H, Haghighi-Kakhki H, Bashir RA, Ahting U, Feichtinger RG, Mayr JA, Rötig A, Lebre AS, Klopstock T, Dworschak A, Pulido N, Saeed MA, Saleh-Gohari N, Holzerova E, Chinnery PF, Taylor RW, Prokisch H. Sengers syndrome: six novel AGK mutations in seven new families and review of the phenotypic and mutational spectrum of 29 patients. Orphanet J Rare Dis 2014; 9:119. [PMID: 25208612 PMCID: PMC4167147 DOI: 10.1186/s13023-014-0119-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 07/17/2014] [Indexed: 01/28/2023] Open
Abstract
Background Sengers syndrome is an autosomal recessive condition characterized by congenital cataract, hypertrophic cardiomyopathy, skeletal myopathy and lactic acidosis. Mutations in the acylglycerol kinase (AGK) gene have been recently described as the cause of Sengers syndrome in nine families. Methods We investigated the clinical and molecular features of Sengers syndrome in seven new families; five families with the severe and two with the milder form. Results Sequence analysis of AGK revealed compound heterozygous or homozygous predicted loss-of-function mutations in all affected individuals. A total of eight different disease alleles were identified, of which six were novel, homozygous c.523_524delAT (p.Ile175Tyrfs*2), c.424-1G > A (splice site), c.409C > T (p.Arg137*) and c.877 + 3G > T (splice site), and compound heterozygous c.871C > T (p.Gln291*) and c.1035dup (p.Ile346Tyrfs*39). All patients displayed perinatal or early-onset cardiomyopathy and cataract, clinical features pathognomonic for Sengers syndrome. Other common findings included blood lactic acidosis and tachydyspnoea while nystagmus, eosinophilia and cervical meningocele were documented in only either one or two cases. Deficiency of the adenine nucleotide translocator was found in heart and skeletal muscle biopsies from two patients associated with respiratory chain complex I deficiency. In contrast to previous findings, mitochondrial DNA content was normal in both tissues. Conclusion We compare our findings to those in 21 previously reported AGK mutation-positive Sengers patients, confirming that Sengers syndrome is a clinically recognisable disorder of mitochondrial energy metabolism.
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Affiliation(s)
- Alireza Haghighi
- Department of Genetics, Harvard Medical School, 77 Ave Louis Pasteur, Boston 02115, MA, USA.
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Murataeva N, Straiker A, Mackie K. Parsing the players: 2-arachidonoylglycerol synthesis and degradation in the CNS. Br J Pharmacol 2014; 171:1379-91. [PMID: 24102242 PMCID: PMC3954479 DOI: 10.1111/bph.12411] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/29/2013] [Accepted: 09/08/2013] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED The endogenous cannabinoid signalling system, composed of endogenous cannabinoids, cannabinoid receptors and the enzymes that synthesize and degrade the endogenous cannabinoids, is much more complex than initially conceptualized. 2-Arachidonoylglycerol (2-AG) is the most abundant endocannabinoid and plays a major role in CNS development and synaptic plasticity. Over the past decade, many key players in 2-AG synthesis and degradation have been identified and characterized. Most 2-AG is synthesized from membrane phospholipids via sequential activation of a phospholipase Cβ and a diacylglycerol lipase, although other pathways may contribute in specialized settings. 2-AG breakdown is more complicated with at least eight different enzymes participating. These enzymes can either degrade 2-AG into its components, arachidonic acid and glycerol, or transform 2-AG into highly bioactive signal molecules. The implications of the precise temporal and spatial control of the expression and function of these pleiotropic metabolizing enzymes have only recently come to be appreciated. In this review, we will focus on the primary organization of the synthetic and degradative pathways of 2-AG and then discuss more recent findings and their implications, with an eye towards the biological and therapeutic implications of manipulating 2-AG synthesis and metabolism. LINKED ARTICLES This article is part of a themed section on Cannabinoids 2013. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-6.
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Affiliation(s)
- N Murataeva
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana UniversityBloomington, IN, USA
| | - A Straiker
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana UniversityBloomington, IN, USA
| | - K Mackie
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana UniversityBloomington, IN, USA
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Chen X, Ying Z, Lin X, Lin H, Wu J, Li M, Song L. Acylglycerol kinase augments JAK2/STAT3 signaling in esophageal squamous cells. J Clin Invest 2013; 123:2576-89. [PMID: 23676499 DOI: 10.1172/jci68143] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 03/14/2013] [Indexed: 02/06/2023] Open
Abstract
JAK2 activity is tightly controlled through a self-inhibitory effect via its JAK homology domain 2 (JH2), which restricts the strength and duration of JAK2/STAT3 signaling under physiological conditions. Although multiple mutations within JAK2, which abrogate the function of JH2 and sustain JAK2 activation, are widely observed in hematological malignancies, comparable mutations have not been detected in solid tumors. How solid tumor cells override the autoinhibitory effect of the JH2 domain to maintain constitutive activation of JAK2/STAT3 signaling remains puzzling. Herein, we demonstrate that AGK directly interacted with the JH2 domain to relieve inhibition of JAK2 and activate JAK2/STAT3 signaling. Overexpression of AGK sustained constitutive JAK2/STAT3 activation, consequently promoting the cancer stem cell population and augmenting the tumorigenicity of esophageal squamous cell carcinoma (ESCC) cells both in vivo and in vitro. Furthermore, AGK levels significantly correlated with increased STAT3 phosphorylation, poorer disease-free survival, and shorter overall survival in primary ESCC. More importantly, AGK expression was significantly correlated with JAK2/STAT3 hyperactivation in ESCC, as well as in lung and breast cancer. These findings uncover a mechanism for constitutive activation of JAK2/STAT3 signaling in solid tumors and may represent a prognostic biomarker and therapeutic target.
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Affiliation(s)
- Xiuting Chen
- State Key Laboratory of Oncology in Southern China, Department of Experimental Research, Cancer Center, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
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Siriwardena K, Mackay N, Levandovskiy V, Blaser S, Raiman J, Kantor PF, Ackerley C, Robinson BH, Schulze A, Cameron JM. Mitochondrial citrate synthase crystals: novel finding in Sengers syndrome caused by acylglycerol kinase (AGK) mutations. Mol Genet Metab 2013; 108:40-50. [PMID: 23266196 DOI: 10.1016/j.ymgme.2012.11.282] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 11/24/2012] [Indexed: 11/16/2022]
Abstract
We report on two families with Sengers syndrome and mutations in the acylglycerol kinase gene (AGK). In the first family, two brothers presented with vascular strokes, lactic acidosis, cardiomyopathy and cataracts, abnormal muscle cell histopathology and mitochondrial function. One proband had very abnormal mitochondria with citrate synthase crystals visible in electron micrographs, associated with markedly high citrate synthase activity. Exome sequencing was used to identify mutations in the AGK gene in the index patient. Targeted sequencing confirmed the same homozygous mutation (c.3G>A, p.M1I) in the brother. The second family had four affected members, of which we examined two. They also presented with similar clinical symptoms, but no strokes. Postmortem heart and skeletal muscle tissues showed low complex I, III and IV activities in the heart, but normal in the muscle. Skin fibroblasts showed elevated lactate/pyruvate ratios and low complex I+III activity. Targeted sequencing led to identification of a homozygous c.979A>T, p.K327* mutation. AGK is located in the mitochondria and phosphorylates monoacylglycerol and diacylglycerol to lysophosphatidic acid and phosphatidic acid. Disruption of these signaling molecules affects the mitochondria's response to superoxide radicals, resulting in oxidative damage to mitochondrial DNA, lipids and proteins, and stimulation of cellular detoxification pathways. High levels of manganese superoxide dismutase protein were detected in all four affected individuals, consistent with increased free radical damage. Phosphatidic acid is also involved in the synthesis of phospholipids and its loss will result in changes to the lipid composition of the inner mitochondrial membrane. These effects manifest as cataract formation in the eye, respiratory chain dysfunction and cardiac hypertrophy in heart tissue. These two pedigrees confirm that mutation of AGK is responsible for the severe neonatal presentation of Sengers syndrome. The identification of citrate synthase precipitates by electron microscopy and the presence of vascular strokes in two siblings may expand the cellular and clinical phenotype of this disease.
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Affiliation(s)
- Komudi Siriwardena
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada M5G 1X8
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Biosynthesis of alkyl lysophosphatidic acid by diacylglycerol kinases. Biochem Biophys Res Commun 2012; 422:758-63. [PMID: 22627129 DOI: 10.1016/j.bbrc.2012.05.077] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 05/12/2012] [Indexed: 02/02/2023]
Abstract
Lysophosphatidic acid (LPA) designates a family of bioactive phosphoglycerides that differ in the length and degree of saturation of their radyl chain. Additional diversity is provided by the linkage of the radyl chain to glycerol: acyl, alkyl, or alk-1-enyl. Acyl-LPAs are the predominate species in tissues and biological fluids. Alkyl-LPAs exhibit distinct pharmacodynamics at LPA receptors, potently drive platelet aggregation, and contribute to ovarian cancer aggressiveness. Multiple biosynthetic pathways exist for alkyl-LPA production. Herein we report that diacylglycerol kinases (DGKs) contribute to cell-associated alkyl-LPA production involving phosphorylation of 1-alkyl-2-acetyl glycerol and document the biosynthesis of alkyl-LPA by DGKs in SKOV-3 ovarian cancer cells, specifically identifying the contribution of DGKα. Concurrently, we discovered that treating SKOV-3 ovarian cancer cell with a sphingosine analog stimulates conversion of exogenous 1-alkyl-2-acetyl glycerol to alkyl-LPA, indicating that DGKα contributes significantly to the production of alkyl-LPA in SKOV-3 cells and identifying cross-talk between the sphingolipid and glycerol lipid pathways.
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Aldahmesh MA, Khan AO, Mohamed JY, Alghamdi MH, Alkuraya FS. Identification of a truncation mutation of acylglycerol kinase (AGK) gene in a novel autosomal recessive cataract locus. Hum Mutat 2012; 33:960-2. [DOI: 10.1002/humu.22071] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 02/26/2012] [Indexed: 11/08/2022]
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McElwain MA, Ko DC, Gordon MD, Fyrst H, Saba JD, Nusse R. A suppressor/enhancer screen in Drosophila reveals a role for wnt-mediated lipid metabolism in primordial germ cell migration. PLoS One 2011; 6:e26993. [PMID: 22069480 PMCID: PMC3206050 DOI: 10.1371/journal.pone.0026993] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 10/07/2011] [Indexed: 11/18/2022] Open
Abstract
Wnt proteins comprise a large family of secreted ligands implicated in a wide variety of biological roles. WntD has previously been shown to inhibit the nuclear accumulation of Dorsal/NF-κB protein during embryonic dorsal/ventral patterning and the adult innate immune response, independent of the well-studied Armadillo/β-catenin pathway. In this paper, we present a novel phenotype for WntD mutant embryos, suggesting that this gene is involved in migration of primordial germ cells (PGC) to the embryonic gonad. Additionally, we describe a genetic suppressor/enhancer screen aimed at identifying genes required for WntD signal transduction, based on the previous observation that maternal overexpression of WntD results in lethally dorsalized embryos. Using an algorithm to narrow down our hits from the screen, we found two novel WntD signaling components: Fz4, a member of the Frizzled family, and the Drosophila Ceramide Kinase homolog, Dcerk. We show here that Dcerk and Dmulk (Drosophila Multi-substrate lipid kinase) redundantly mediate PGC migration. Our data are consistent with a model in which the activity of lipid phosphate phosphatases shapes a concentration gradient of ceramide-1-phosphate (C1P), the product of Dcerk, allowing proper PGC migration.
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MESH Headings
- Animals
- Animals, Genetically Modified
- Blotting, Southern
- Blotting, Western
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cell Movement
- Ceramides/metabolism
- Drosophila/genetics
- Drosophila/growth & development
- Drosophila/metabolism
- Drosophila Proteins/genetics
- Drosophila Proteins/metabolism
- Embryo, Nonmammalian/cytology
- Embryo, Nonmammalian/metabolism
- Enhancer Elements, Genetic
- Female
- Genetic Testing
- Germ Cells/physiology
- Immunoprecipitation
- Intracellular Signaling Peptides and Proteins/genetics
- Intracellular Signaling Peptides and Proteins/metabolism
- Lipid Metabolism
- Male
- Phylogeny
- RNA, Messenger/genetics
- Real-Time Polymerase Chain Reaction
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction
- Suppression, Genetic
- beta Catenin/metabolism
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Affiliation(s)
- Mark A. McElwain
- Howard Hughes Medical Institute, Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Dennis C. Ko
- Howard Hughes Medical Institute, Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Michael D. Gordon
- Howard Hughes Medical Institute, Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Henrik Fyrst
- Center for Cancer Research, Children's Hospital Oakland Research Institute, Oakland, California, United States of America
| | - Julie D. Saba
- Center for Cancer Research, Children's Hospital Oakland Research Institute, Oakland, California, United States of America
| | - Roel Nusse
- Howard Hughes Medical Institute, Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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37
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Shulga YV, Topham MK, Epand RM. Regulation and functions of diacylglycerol kinases. Chem Rev 2011; 111:6186-208. [PMID: 21800853 DOI: 10.1021/cr1004106] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yulia V Shulga
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
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38
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Diacylglycerol kinases as sources of phosphatidic acid. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:942-8. [PMID: 19264149 DOI: 10.1016/j.bbalip.2009.02.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 02/18/2009] [Accepted: 02/18/2009] [Indexed: 11/22/2022]
Abstract
There are ten mammalian diacylglycerol kinases (DGKs) whose primary role is to terminate diacylglycerol (DAG) signaling. However, it is becoming increasingly apparent that DGKs also influence signaling events through their product, phosphatidic acid (PA). They do so in some cases by associating with proteins and then modifying their activity by generating PA. In other cases, DGKs broadly regulate signaling events by virtue of their ability to provide PA for the synthesis of phosphatidylinositols (PtdIns).
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39
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Zhao Y, Natarajan V. Lysophosphatidic acid signaling in airway epithelium: role in airway inflammation and remodeling. Cell Signal 2009; 21:367-77. [PMID: 18996473 PMCID: PMC2660380 DOI: 10.1016/j.cellsig.2008.10.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 09/27/2008] [Accepted: 10/21/2008] [Indexed: 02/07/2023]
Abstract
Lysophosphatidic acid (LPA), a potent bioactive phospholipid, induces diverse cellular responses, including cell proliferation, migration, and cytokine release. LPA can be generated intracellularly and extracellularly through multiple synthetic pathways by action of various enzymes, such as phospholipase A(1/2) (PLA(1/2)), phospholipase D (PLD), acylglycerol kinase (AGK), and lysophospholipase D (lysoPLD). Metabolism of LPA is regulated by a family of lipid phosphate phosphatases (LPPs). Significant amounts of LPA have been detected in various biological fluids, including serum, saliva, and bronchoalveolar lavage fluid (BALF). The most significant effects of LPA appear to be through activation of the G-protein-coupled receptors (GPCRs), termed LPA(1-6). LPA regulates gene expression through activation of several transcriptional factors, such as nuclear factor-kappaB (NF-kappaB), AP-1, and C/EBPbeta. In addition to GPCRs, cross-talk between LPA receptors and receptor tyrosine kinases (RTKs) partly regulates LPA-induced intracellular signaling and cellular responses. Airway epithelial cells participate in innate immunity through the release of cytokines, chemokines, lipid mediators, other inflammatory mediators and an increase in barrier function in response to a variety of inhaled stimuli. Expression of LPA receptors has been demonstrated in airway epithelial cells. This review summarizes our recent observations of the role of LPA/LPA-Rs in regulation of airway epithelium, especially in relation to the secretion of pro- and anti-inflammatory mediators and regulation of airway barrier function.
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Affiliation(s)
- Yutong Zhao
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA.
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40
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Kalari S, Zhao Y, Spannhake EW, Berdyshev EV, Natarajan V. Role of acylglycerol kinase in LPA-induced IL-8 secretion and transactivation of epidermal growth factor-receptor in human bronchial epithelial cells. Am J Physiol Lung Cell Mol Physiol 2008; 296:L328-36. [PMID: 19112101 DOI: 10.1152/ajplung.90431.2008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
LPA (lysophosphatidic acid) is a potent bioactive phospholipid, which regulates a number of diverse cellular responses through G protein-coupled LPA receptors. Intracellular LPA is generated by the phosphorylation of monoacylglycerol by acylglycerol kinase (AGK); however, the role of intracellular LPA in signaling and cellular responses remains to be elucidated. Here, we investigated signaling pathways of IL-8 secretion mediated by AGK and intracellular LPA in human bronchial epithelial cells (HBEpCs). Expression of AGK in HBEpCs was detected by real-time PCR, and overexpressed AGK was mainly localized in mitochondria as determined by immunofluorescence and confocal microscopy. Overexpression of lentiviral AGK wild type increased intracellular LPA production ( approximately 1.8-fold), enhanced LPA-mediated IL-8 secretion, and stimulated tyrosine phosphorylation epidermal growth factor-receptor (EGF-R). Furthermore, downregulation of native AGK by AGK small interfering RNA decreased intracellular LPA levels ( approximately 2-fold) and attenuated LPA-induced p38 MAPK, JNK, and NF-kappaB activation, tyrosine phosphorylation of EGF-R, and IL-8 secretion. These results suggest that native AGK regulates LPA-mediated IL-8 secretion involving MAPKs, NF-kappaB, and transactivation of EGF-R. Thus AGK may play an important role in innate immunity and airway remodeling during inflammation.
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Affiliation(s)
- Satish Kalari
- Department of Medicine, Section of Pulmonary and Critical Care Medicine, The University of Chicago, Chicago, Illinois, USA
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41
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Graf C, Zemann B, Rovina P, Urtz N, Schanzer A, Reuschel R, Mechtcheriakova D, Müller M, Fischer E, Reichel C, Huber S, Dawson J, Meingassner JG, Billich A, Niwa S, Badegruber R, Van Veldhoven PP, Kinzel B, Baumruker T, Bornancin F. Neutropenia with impaired immune response to Streptococcus pneumoniae in ceramide kinase-deficient mice. THE JOURNAL OF IMMUNOLOGY 2008; 180:3457-66. [PMID: 18292572 DOI: 10.4049/jimmunol.180.5.3457] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In mammals, ceramide kinase (CerK)-mediated phosphorylation of ceramide is the only known pathway to ceramide-1-phosphate (C1P), a recently identified signaling sphingolipid metabolite. To help delineate the roles of CerK and C1P, we knocked out the gene of CerK in BALB/c mice by homologous recombination. All in vitro as well as cell-based assays indicated that CerK activity is completely abolished in Cerk-/- mice. Labeling with radioactive orthophosphate showed a profound reduction in the levels of de novo C1P formed in Cerk-/- macrophages. Consistently, mass spectrometry analysis revealed a major contribution of CerK to the formation of C16-C1P. However, the significant residual C1P levels in Cerk-/- animals indicate that alternative routes to C1P exist. Furthermore, serum levels of proapoptotic ceramide in these animals were significantly increased while levels of dihydroceramide as the biosynthetic precursor were reduced. Previous literature pointed to a role of CerK or C1P in innate immune cell function. Using a variety of mechanistic and disease models, as well as primary cells, we found that macrophage- and mast cell-dependent readouts are barely affected in the absence of CerK. However, the number of neutrophils was strikingly reduced in blood and spleen of Cerk-/- animals. When tested in a model of fulminant pneumonia, Cerk-/- animals developed a more severe disease, lending support to a defect in neutrophil homeostasis following CerK ablation. These results identify ceramide kinase as a key regulator of C1P, dihydroceramide and ceramide levels, with important implications for neutrophil homeostasis and innate immunity regulation.
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Affiliation(s)
- Christine Graf
- Novartis Institutes for BioMedical Research, Vienna, Austria
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42
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Lyssand JS, Bajjalieh SM. The heterotrimeric [corrected] G protein subunit G alpha i is present on mitochondria. FEBS Lett 2007; 581:5765-8. [PMID: 18037379 DOI: 10.1016/j.febslet.2007.11.044] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 11/07/2007] [Accepted: 11/12/2007] [Indexed: 01/20/2023]
Abstract
Receptors that signal through heterotrimeric [corrected] GTP binding (G) proteins mediate the majority of intercellular communication. Recent evidence suggests that receptors acting through G proteins also transfer signals across the nuclear membrane. Here we present cell fractionation and immunolabeling data showing that the heterotrimeric [corrected] G protein subunit Galphai is associated with mitochondria. This finding suggests that G protein receptor signaling may be a feature common to all membranes.
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Affiliation(s)
- John S Lyssand
- Department of Pharmacology, University of Washington Seattle, Box 357750, WA, USA
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43
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Epand RM, Shulga YV, Timmons HC, Perri AL, Belani JD, Perinpanathan K, Johnson-McIntire LB, Bajjalieh S, Dicu AO, Elias C, Rychnovsky SD, Topham MK. Substrate chirality and specificity of diacylglycerol kinases and the multisubstrate lipid kinase. Biochemistry 2007; 46:14225-31. [PMID: 18004883 DOI: 10.1021/bi701584v] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The alpha, zeta, and epsilon isoforms of diacylglycerol kinase exhibit a high degree of stereospecificity in the phosphorylation of diacylglycerol. In comparison, a multiple lipid kinase, MuLK, shows much less stereospecificity, phosphorylating 1,2-dioleoylglycerol only approximately 2-3 times more rapidly than 2,3-dioleoylglycerol. The alpha and zeta isoforms of diacylglycerol kinase are inhibited by 2,3-dioleoylglycerol, but not the more substrate-selective epsilon isoform. The inhibition by 2,3-dioleoylglycerol is uncompetitive. This corresponds to a kinetic scheme in which the inhibitor can bind to the enzyme-substrate complex, but not to the free enzyme. Our data indicate that despite their similar structures, 1,2-dioleoylglycerol and 2,3-dioleoylglycerol do not compete for the active site of these three isoforms of diacylglycerol kinase. We suggest that the 2,3-dioleoylglycerol binds to a site on the alpha and zeta isoforms of diacylglycerol kinase that is exposed as a consequence of the substrate binding to the active site. The chiral specificity of these enzymes thus mimics the substrate specificity, with MuLK being the least selective and the epsilon isoform of diacylglycerol kinase exhibiting the greatest selectivity.
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Affiliation(s)
- Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada.
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44
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Bakali HMA, Herman MD, Johnson KA, Kelly AA, Wieslander A, Hallberg BM, Nordlund P. Crystal structure of YegS, a homologue to the mammalian diacylglycerol kinases, reveals a novel regulatory metal binding site. J Biol Chem 2007; 282:19644-52. [PMID: 17351295 DOI: 10.1074/jbc.m604852200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The human lipid kinase family controls cell proliferation, differentiation, and tumorigenesis and includes diacylglycerol kinases, sphingosine kinases, and ceramide kinases. YegS is an Escherichia coli protein with significant sequence homology to the catalytic domain of the human lipid kinases. We have solved the crystal structure of YegS and shown that it is a lipid kinase with phosphatidylglycerol kinase activity. The crystal structure reveals a two-domain protein with significant structural similarity to a family of NAD kinases. The active site is located in the interdomain cleft formed by four conserved sequence motifs. Surprisingly, the structure reveals a novel metal binding site composed of residues conserved in most lipid kinases.
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Affiliation(s)
- H M Amin Bakali
- Division of Biophysics, Department of Medical Biochemistry and Biophysics, Karolinska Institute, SE-171 77 Stockholm, Sweden
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45
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Graf C, Rovina P, Tauzin L, Schanzer A, Bornancin F. Enhanced ceramide-induced apoptosis in ceramide kinase overexpressing cells. Biochem Biophys Res Commun 2007; 354:309-14. [PMID: 17222802 DOI: 10.1016/j.bbrc.2006.12.208] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2006] [Accepted: 12/30/2006] [Indexed: 12/22/2022]
Abstract
We evaluated how increased levels of ceramide kinase (CerK) would impact the growth of COS-1 fibroblasts and RBL-2H3 basophils. The low CerK activity in these cells was strongly up-regulated upon recombinant expression of CerK. CerK-overexpressing COS-1 cells depended on higher concentrations of serum for their growth and displayed many filipodia. The two CerK-overexpressing cell lines were more sensitive to C2-ceramide-mediated apoptosis, and this correlated with the production of C2-ceramide-1-phosphate by CerK. This study indicates that ceramide kinase may participate in the control of cell growth, and establishes a novel assay that will be valuable for testing ceramide kinase inhibitors.
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Affiliation(s)
- Christine Graf
- Novartis Institutes for BioMedical Research, Brunnerstrasse 59, A-1235 Vienna, Austria
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46
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Epand RM, Topham MK. Measurement of mammalian diacylglycerol kinase activity in vitro and in cells. Methods Enzymol 2007; 434:293-304. [PMID: 17954254 DOI: 10.1016/s0076-6879(07)34016-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Diacylglycerol kinase (DGK) catalyzes the conversion of diacylglycerol to phosphatidic acid. Because both the lipid substrate and the product are important in regulation, this enzyme plays an important role in signal transduction. In mammals there are several isoforms of diacylglycerol kinase. Their activities can be evaluated in vitro as well as in intact cells. In vitro assays are based on measuring the incorporation of (32)P from ATP into diacylglycerol, resulting in the formation of labeled phosphatidic acid. Diacylglycerol with long acyl chains is insoluble in water and must be dispersed with detergent or incorporated into liposomes. Detergent-based assays are easier to perform and generally more precise; however, liposomes more closely resemble the organization of biological membranes and also allow for the testing of the modulation of enzyme activity by changes in the physical or chemical properties of the membrane. The micelle assay can also be used to measure DGK activity in cellular organelles after stimulation of intact cells to activate particular DGK isoforms. This will assess the translocation of DGK among different subcellular compartments. In this regard the plasma membrane and nucleus appear to be particularly important for the regulatory actions of these enzymes. Finally, one can also measure the DGK activity in whole cells that have been prelabeled with [(32)P]phosphate and determine the incorporation of label into phosphatidic acid that can be extracted from the whole cell or from cellular organelles.
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Affiliation(s)
- Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University Health Sciences Centre, Hamilton, Ontario, Canada
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47
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Vandevoorde S, Jonsson KO, Labar G, Persson E, Lambert DM, Fowler CJ. Lack of selectivity of URB602 for 2-oleoylglycerol compared to anandamide hydrolysis in vitro. Br J Pharmacol 2006; 150:186-91. [PMID: 17143303 PMCID: PMC2042901 DOI: 10.1038/sj.bjp.0706971] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Two compounds, URB602 and URB754, have been reported in the literature to be selective inhibitors of monoacylglycerol lipase, although a recent study has questioned their ability to prevent 2-arachidonoyl hydrolysis by brain homogenates and cerebellar membranes. In the present study, the ability of these compounds to inhibit monoacylglycerol lipase and fatty acid amide hydrolase has been reinvestigated. EXPERIMENTAL APPROACH Homogenates and cell lines were incubated with test compounds and, thereafter, with either [(3)H]-2-oleoylglycerol or [(3)H]-anandamide. Labelled reaction products were separated from substrate using chloroform: methanol extraction. KEY RESULTS In cytosolic fractions from rat brain, URB602 and URB754 inhibited the hydrolysis of 2-oleoylglycerol with IC(50) values of 25 and 48 microM, respectively. Anandamide hydrolysis by brain membranes was not sensitive to URB754, but was inhibited by URB602 (IC(50) value 17 microM). Hydrolysis of 2-oleoylglycerol by human recombinant monoacylglycerol lipase was sensitive to URB602, but not URB754. The lack of selectivity of URB602 for 2-oleoylglycerol compared to anandamide hydrolysis was also observed for intact RBL2H3 basophilic leukaemia cells. C6 glioma expressed mRNA for monoacylglycerol lipase, and hydrolyzed 2-oleoylglycerol in a manner sensitive to inhibition by methyl arachidonoyl fluorophosphonate but not URB754 or URB597. MC3T3-E1 mouse osteoblastic cells, which did not express mRNA for monoacylglycerol lipase, hydrolyzed 2-oleoylglycerol in the presence of URB597, but the hydrolysis was less sensitive to methyl arachidonoyl fluorophosphonate than for C6 cells. CONCLUSIONS AND IMPLICATIONS The data demonstrate that the compounds URB602 and URB754 do not behave as selective and/or potent inhibitors of monoacylglycerol lipase.
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Affiliation(s)
- S Vandevoorde
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
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48
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Spiegel S, Milstien S. Functions of the multifaceted family of sphingosine kinases and some close relatives. J Biol Chem 2006; 282:2125-9. [PMID: 17135245 DOI: 10.1074/jbc.r600028200] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Affiliation(s)
- Sarah Spiegel
- Department of Biochemistry, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298, USA.
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49
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Rovina P, Jaritz M, Höfinger S, Graf C, Dévay P, Billich A, Baumruker T, Bornancin F. A critical beta6-beta7 loop in the pleckstrin homology domain of ceramide kinase. Biochem J 2006; 400:255-65. [PMID: 16872273 PMCID: PMC1652822 DOI: 10.1042/bj20060316] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CerK (ceramide kinase) produces ceramide 1-phosphate, a sphingophospholipid with recognized signalling properties. It localizes to the Golgi complex and fractionates essentially between detergent-soluble and -insoluble fractions; however, the determinants are unknown. Here, we made a detailed mutagenesis study of the N-terminal PH domain (pleckstrin homology domain) of CerK, based on modelling, and identified key positively charged amino acid residues within an unusual motif in the loop interconnecting beta-strands 6 and 7. These residues are critical for CerK membrane association and polyphosphoinositide binding and activity. Their mutagenesis results in increased thermolability, sensitivity to proteolysis, reduced apparent molecular mass as well as propensity of the recombinant mutant protein to aggregate, indicating that this loop impacts the overall conformation of the CerK protein. This is in contrast with most PH domains whose function strongly relies on charges located in the beta1-beta2 loop.
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Affiliation(s)
- Philipp Rovina
- Novartis Institutes for BioMedical Research, Brunnerstrasse 59, A-1235 Vienna, Austria
| | - Markus Jaritz
- Novartis Institutes for BioMedical Research, Brunnerstrasse 59, A-1235 Vienna, Austria
| | - Siegfried Höfinger
- Novartis Institutes for BioMedical Research, Brunnerstrasse 59, A-1235 Vienna, Austria
| | - Christine Graf
- Novartis Institutes for BioMedical Research, Brunnerstrasse 59, A-1235 Vienna, Austria
| | - Piroska Dévay
- Novartis Institutes for BioMedical Research, Brunnerstrasse 59, A-1235 Vienna, Austria
| | - Andreas Billich
- Novartis Institutes for BioMedical Research, Brunnerstrasse 59, A-1235 Vienna, Austria
| | - Thomas Baumruker
- Novartis Institutes for BioMedical Research, Brunnerstrasse 59, A-1235 Vienna, Austria
| | - Frédéric Bornancin
- Novartis Institutes for BioMedical Research, Brunnerstrasse 59, A-1235 Vienna, Austria
- To whom correspondence should be addressed (email )
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50
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Van Overloop H, Gijsbers S, Van Veldhoven PP. Further characterization of mammalian ceramide kinase: substrate delivery and (stereo)specificity, tissue distribution, and subcellular localization studies. J Lipid Res 2006; 47:268-83. [PMID: 16269826 DOI: 10.1194/jlr.m500321-jlr200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recombinant human ceramide kinase (HsCERK) was analyzed with regard to dependence on divalent cations and to substrate delivery, spectrum, specificity, and stereoselectivity. Depending on the chain length of the ceramide, either albumin for short-chain ceramide or a mixed micellar form (octylglucoside/cardiolipin) for long-chain ceramide was preferred for the substrate delivery, the former resulting in higher activities. Bacterially expressed HsCERK was highly dependent on Mg2+ ions, much less on Ca2+ ions. A clear preference for the d-erythro isomer was seen. Various N-acylated amino alcohols were no substrate, but N-hexanoyl-1-O-hexadecyl-2-desoxy-2-amino-sn-glycerol and N-tetradecanoyl-2S-amino-1-butanol were phosphorylated, suggesting that the secondary hydroxy group is not required for recognition. The properties of HsCERK, expressed in CHO cells, were similar to those of the bacterially expressed protein, including the Mg2+ dependence. In mouse, the highest activities were found in testis and cerebellum, and upon subcellular fractionation the activity was recovered mainly in the microsomal fraction. This fits with the plasma membrane localization in CHO cells, which was mediated by the N-terminal putative pleckstrin domain. No evidence for phosphorylation of ceramide by the recently described multiple lipid kinase was found. The latter kinase is localized in the mitochondria, but no firm conclusions with regard to its substrate could be drawn.
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Affiliation(s)
- Helena Van Overloop
- Katholieke Universiteit Leuven, Faculteit Geneeskunde, Departement Moleculaire Celbiologie, Afdeling Farmacologie, Leuven, Belgium
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