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Orosz G, Szabó L, Bereti S, Zámbó V, Csala M, Kereszturi É. Molecular Basis of Unequal Alternative Splicing of Human SCD5 and Its Alteration by Natural Genetic Variations. Int J Mol Sci 2023; 24:ijms24076517. [PMID: 37047490 PMCID: PMC10095032 DOI: 10.3390/ijms24076517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/22/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023] Open
Abstract
Alternative splicing (AS) is a major means of post-transcriptional control of gene expression, and provides a dynamic versatility of protein isoforms. Cancer-related AS disorders have diagnostic, prognostic and therapeutic values. Changes in the expression and AS of human stearoyl-CoA desaturase-5 (SCD5) are promising specific tumor markers, although the transcript variants (TVs) of the gene have not yet been confirmed. Our in silico, in vitro and in vivo study focuses on the distribution of SCD5 TVs (A and B) in human tissues, the functionality of the relevant splice sites, and their modulation by certain single-nucleotide variations (SNVs). An order of magnitude higher SCD5A expression was found compared with SCD5B. This unequal splicing is attributed to a weaker recognition of the SCD5B-specific splicing acceptor site, based on predictions confirmed by an optimized minigene assay. The pronounced dominance of SCD5A was largely modified (rs1430176385_A, rs1011850309_A) or even inverted (rs1011850309_C) by natural SNVs at the TV-specific splice sites. Our results provide long missing data on the proportion of SCD5 TVs in human tissues and reveal mutation-driven changes in SCD5 AS, potentially affecting tumor-associated reprogramming of lipid metabolism, thus having prognostic significance, which may be utilized for novel and personalized therapeutic approaches.
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Affiliation(s)
- Gabriella Orosz
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Luca Szabó
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Szanna Bereti
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Veronika Zámbó
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Miklós Csala
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Éva Kereszturi
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
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2
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The phospholipase A 2 superfamily as a central hub of bioactive lipids and beyond. Pharmacol Ther 2023; 244:108382. [PMID: 36918102 DOI: 10.1016/j.pharmthera.2023.108382] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/13/2023]
Abstract
In essence, "phospholipase A2" (PLA2) means a group of enzymes that release fatty acids and lysophospholipids by hydrolyzing the sn-2 position of glycerophospholipids. To date, more than 50 enzymes possessing PLA2 or related lipid-metabolizing activities have been identified in mammals, and these are subdivided into several families in terms of their structures, catalytic mechanisms, tissue/cellular localizations, and evolutionary relationships. From a general viewpoint, the PLA2 superfamily has mainly been implicated in signal transduction, driving the production of a wide variety of bioactive lipid mediators. However, a growing body of evidence indicates that PLA2s also contribute to phospholipid remodeling or recycling for membrane homeostasis, fatty acid β-oxidation for energy production, and barrier lipid formation on the body surface. Accordingly, PLA2 enzymes are considered one of the key regulators of a broad range of lipid metabolism, and perturbation of specific PLA2-driven lipid pathways often disrupts tissue and cellular homeostasis and may be associated with a variety of diseases. This review covers current understanding of the physiological functions of the PLA2 superfamily, focusing particularly on the two major intracellular PLA2 families (Ca2+-dependent cytosolic PLA2s and Ca2+-independent patatin-like PLA2s) as well as other PLA2 families, based on studies using gene-manipulated mice and human diseases in combination with comprehensive lipidomics.
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3
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The Short-Term Opening of Cyclosporin A-Independent Palmitate/Sr2+-Induced Pore Can Underlie Ion Efflux in the Oscillatory Mode of Functioning of Rat Liver Mitochondria. MEMBRANES 2022; 12:membranes12070667. [PMID: 35877870 PMCID: PMC9319229 DOI: 10.3390/membranes12070667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 11/17/2022]
Abstract
Mitochondria are capable of synchronized oscillations in many variables, but the underlying mechanisms are still unclear. In this study, we demonstrated that rat liver mitochondria, when exposed to a pulse of Sr2+ ions in the presence of valinomycin (a potassium ionophore) and cyclosporin A (a specific inhibitor of the permeability transition pore complex) under hypotonia, showed prolonged oscillations in K+ and Sr2+ fluxes, membrane potential, pH, matrix volume, rates of oxygen consumption and H2O2 formation. The dynamic changes in the rate of H2O2 production were in a reciprocal relationship with the respiration rate and in a direct relationship with the mitochondrial membrane potential and other indicators studied. The pre-incubation of mitochondria with Ca2+(Sr2+)-dependent phospholipase A2 inhibitors considerably suppressed the accumulation of free fatty acids, including palmitic and stearic acids, and all spontaneous Sr2+-induced cyclic changes. These data suggest that the mechanism of ion efflux from mitochondria is related to the opening of short-living pores, which can be caused by the formation of complexes between Sr2+(Ca2+) and endogenous long-chain saturated fatty acids (mainly, palmitic acid) that accumulate due to the activation of phospholipase A2 by the ions. A possible role for transient palmitate/Ca2+(Sr2+)-induced pores in the maintenance of ion homeostasis and the prevention of calcium overload in mitochondria under pathophysiological conditions is discussed.
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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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5
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Murakami M, Sato H, Taketomi Y. Updating Phospholipase A 2 Biology. Biomolecules 2020; 10:E1457. [PMID: 33086624 PMCID: PMC7603386 DOI: 10.3390/biom10101457] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/09/2020] [Accepted: 10/15/2020] [Indexed: 12/30/2022] Open
Abstract
The phospholipase A2 (PLA2) superfamily contains more than 50 enzymes in mammals that are subdivided into several distinct families on a structural and biochemical basis. In principle, PLA2 has the capacity to hydrolyze the sn-2 position of glycerophospholipids to release fatty acids and lysophospholipids, yet several enzymes in this superfamily catalyze other reactions rather than or in addition to the PLA2 reaction. PLA2 enzymes play crucial roles in not only the production of lipid mediators, but also membrane remodeling, bioenergetics, and body surface barrier, thereby participating in a number of biological events. Accordingly, disturbance of PLA2-regulated lipid metabolism is often associated with various diseases. This review updates the current state of understanding of the classification, enzymatic properties, and biological functions of various enzymes belonging to the PLA2 superfamily, focusing particularly on the novel roles of PLA2s in vivo.
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Affiliation(s)
- Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan; (H.S.); (Y.T.)
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6
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Sulakhe D, D'Souza M, Wang S, Balasubramanian S, Athri P, Xie B, Canzar S, Agam G, Gilliam TC, Maltsev N. Exploring the functional impact of alternative splicing on human protein isoforms using available annotation sources. Brief Bioinform 2020; 20:1754-1768. [PMID: 29931155 DOI: 10.1093/bib/bby047] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 05/02/2018] [Indexed: 12/30/2022] Open
Abstract
In recent years, the emphasis of scientific inquiry has shifted from whole-genome analyses to an understanding of cellular responses specific to tissue, developmental stage or environmental conditions. One of the central mechanisms underlying the diversity and adaptability of the contextual responses is alternative splicing (AS). It enables a single gene to encode multiple isoforms with distinct biological functions. However, to date, the functions of the vast majority of differentially spliced protein isoforms are not known. Integration of genomic, proteomic, functional, phenotypic and contextual information is essential for supporting isoform-based modeling and analysis. Such integrative proteogenomics approaches promise to provide insights into the functions of the alternatively spliced protein isoforms and provide high-confidence hypotheses to be validated experimentally. This manuscript provides a survey of the public databases supporting isoform-based biology. It also presents an overview of the potential global impact of AS on the human canonical gene functions, molecular interactions and cellular pathways.
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Affiliation(s)
- Dinanath Sulakhe
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Computation Institute, University of Chicago, 5735 S. Ellis Avenue, Chicago, IL, USA
| | - Mark D'Souza
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA
| | - Sheng Wang
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Toyota Technological Institute at Chicago, 6045 S. Kenwood Avenue, Chicago, IL, USA
| | - Sandhya Balasubramanian
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Genentech, Inc. 1 DNA Way, Mail Stop: 35-6J, South San Francisco, CA, USA
| | - Prashanth Athri
- Department of Computer Science and Engineering, Amrita School of Engineering, Bengaluru, Amrita Vishwa Vidyapeetham, Kasavanahalli, Carmelaram P.O., Bengaluru, Karnataka, India
| | - Bingqing Xie
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Department of Computer Science, Illinois Institute of Technology, Chicago, IL, USA
| | - Stefan Canzar
- Toyota Technological Institute at Chicago, 6045 S. Kenwood Avenue, Chicago, IL, USA.,Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gady Agam
- Department of Computer Science, Illinois Institute of Technology, Chicago, IL, USA
| | - T Conrad Gilliam
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Computation Institute, University of Chicago, 5735 S. Ellis Avenue, Chicago, IL, USA
| | - Natalia Maltsev
- Department of Human Genetics, University of Chicago, 920 E. 58th Street, Chicago, IL, USA.,Computation Institute, University of Chicago, 5735 S. Ellis Avenue, Chicago, IL, USA
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7
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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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8
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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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9
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Zheng C, Zou X, Lin H, Zhao B, Zhang M, Luo C, Fu S. miRNA-185 regulates the VEGFA signaling pathway in dairy cows with retained fetal membranes. Theriogenology 2018; 110:116-121. [DOI: 10.1016/j.theriogenology.2017.12.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 12/29/2017] [Accepted: 12/31/2017] [Indexed: 12/26/2022]
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10
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Lu Y, Kim NM, Jiang YW, Zhang H, Zheng D, Zhu FX, Liang R, Li B, Xu HX. Cambogin suppresses dextran sulphate sodium-induced colitis by enhancing Treg cell stability and function. Br J Pharmacol 2018; 175:1085-1099. [PMID: 29352742 PMCID: PMC5843713 DOI: 10.1111/bph.14150] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 12/18/2017] [Accepted: 12/20/2017] [Indexed: 12/22/2022] Open
Abstract
Background and Purpose Inflammatory bowel disease (IBD) is a chronic and relapsing inflammatory disorder of the gastrointestinal tract, and an impaired immune response plays a critical role in IBD. The current drugs and therapies for IBD treatment are of limited use, therefore, there is a need to find novel drugs or therapies for this disease. We investigated the effect of cambogin in a mouse model of dextran sulphate sodium (DSS)‐induced colitis and whether cambogin attenuates inflammation via a Treg‐cell‐mediated effect on the immune response. Experimental Approach Chronic colitis was established in mice using 2% DSS, and cambogin (10 mg·kg−1, p.o.) was administered for 10 days. Body weight, colon length and colon histology were assessed. Cytokine production was measured using elisa and quantitative real‐time PCR. To evaluate the mechanism of cambogin, human CD4+CD25hiCD127lo Treg cells were isolated from peripheral blood mononuclear cells. Major signalling profiles involved in Treg cell stability were measured. Key Results Cambogin attenuated diarrhoea, colon shortening and colon histological injury and IL‐6, IFN‐γ and TNF‐α production in DSS‐treated mice. Cambogin also up‐regulated Treg cell numbers in both the spleen and mesenteric lymph nodes. Furthermore, cambogin (10 μM) prevented Foxp3 loss in human primary Treg cells in vitro, and promoted USP7‐mediated Foxp3 deubiquitination and increased Foxp3 protein expression in LPS‐treated cells. Conclusions and Implications The effect of cambogin on DSS‐induced colitis is expedited by a Treg‐cell‐mediated modification of the immune response, suggesting that cambogin could be applied as a novel agent for treating colitis and other Treg cell‐related diseases.
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Affiliation(s)
- Yue Lu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Na-Mi Kim
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yi-Wen Jiang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Hong Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Dan Zheng
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Fu-Xiang Zhu
- Key Laboratory of Molecular Virology and Immunology, Unit of Molecular Immunology, Institute Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Rui Liang
- Key Laboratory of Molecular Virology and Immunology, Unit of Molecular Immunology, Institute Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Bin Li
- Unit of Molecular Immunology, Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai JiaoTong University, Shanghai, China
| | - Hong-Xi Xu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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11
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Abstract
Phospholipases are lipolytic enzymes that hydrolyze phospholipid substrates at specific ester bonds. Phospholipases are widespread in nature and play very diverse roles from aggression in snake venom to signal transduction, lipid mediator production, and metabolite digestion in humans. Phospholipases vary considerably in structure, function, regulation, and mode of action. Tremendous advances in understanding the structure and function of phospholipases have occurred in the last decades. This introductory chapter is aimed at providing a general framework of the current understanding of phospholipases and a discussion of their mechanisms of action and emerging biological functions.
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Kotani S, Izawa S, Komai N, Takayanagi A, Arioka M. Mitochondria-localized phospholipase A 2, AoPlaA, in Aspergillus oryzae displays phosphatidylethanolamine-specific activity and is involved in the maintenance of mitochondrial phospholipid composition. Fungal Genet Biol 2016; 96:1-11. [PMID: 27634187 DOI: 10.1016/j.fgb.2016.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/01/2016] [Accepted: 09/01/2016] [Indexed: 10/21/2022]
Abstract
In mammals, cytosolic phospholipases A2 (cPLA2s) play important physiological roles by releasing arachidonic acid, a precursor for bioactive lipid mediators, from the biological membranes. In contrast, fungal cPLA2-like proteins are much less characterized and their roles have remained elusive. AoPlaA is a cPLA2-like protein in the filamentous fungus Aspergillus oryzae which, unlike mammalian cPLA2, localizes to mitochondria. In this study, we investigated the biochemical and physiological functions of AoPlaA. Recombinant AoPlaA produced in E. coli displayed Ca2+-independent lipolytic activity. Mass spectrometry analysis demonstrated that AoPlaA displayed PLA2 activity to phosphatidylethanolamine (PE), but not to other phospholipids, and generated 1-acylated lysoPE. Catalytic site mutants of AoPlaA displayed almost no or largely reduced activity to PE. Consistent with PE-specific activity of AoPlaA, AoplaA-overexpressing strain showed decreased PE content in the mitochondrial fraction. In contrast, AoplaA-disruption strain displayed increased content of cardiolipin. AoplaA-overexpressing strain, but not its counterparts overexpressing the catalytic site mutants, exhibited retarded growth at low temperature, possibly because of the impairment of the mitochondrial function caused by excess degradation of PE. These results suggest that AoPlaA is a novel PE-specific PLA2 that plays a regulatory role in the maintenance of mitochondrial phospholipid composition.
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Affiliation(s)
- Shohei Kotani
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Sho Izawa
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Noriyuki Komai
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ayumi Takayanagi
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Manabu Arioka
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
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Cheung KL, Jarrett R, Subramaniam S, Salimi M, Gutowska-Owsiak D, Chen YL, Hardman C, Xue L, Cerundolo V, Ogg G. Psoriatic T cells recognize neolipid antigens generated by mast cell phospholipase delivered by exosomes and presented by CD1a. J Exp Med 2016; 213:2399-2412. [PMID: 27670592 PMCID: PMC5068234 DOI: 10.1084/jem.20160258] [Citation(s) in RCA: 180] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 08/22/2016] [Indexed: 12/13/2022] Open
Abstract
Psoriasis is a chronic inflammatory skin disease associated with a T helper 17 response. Yet, it has proved challenging to identify relevant peptide-based T cell antigens. Antigen-presenting Langerhans cells show a differential migration phenotype in psoriatic lesions and express constitutively high levels of CD1a, which presents lipid antigens to T cells. In addition, phospholipase A2 (PLA2) is highly expressed in psoriatic lesions and is known to generate neolipid skin antigens for recognition by CD1a-reactive T cells. In this study, we observed expression of a cytoplasmic PLA2 (PLA2G4D) in psoriatic mast cells but, unexpectedly, also found PLA2G4D activity to be extracellular. This was explained by IFN-α-induced mast cell release of exosomes, which transferred cytoplasmic PLA2 activity to neighboring CD1a-expressing cells. This led to the generation of neolipid antigens and subsequent recognition by lipid-specific CD1a-reactive T cells inducing production of IL-22 and IL-17A. Circulating and skin-derived T cells from patients with psoriasis showed elevated PLA2G4D responsiveness compared with healthy controls. Overall, these data present an alternative model of psoriasis pathogenesis in which lipid-specific CD1a-reactive T cells contribute to psoriatic inflammation. The findings suggest that PLA2 inhibition or CD1a blockade may have therapeutic potential for psoriasis.
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Affiliation(s)
- Ka Lun Cheung
- Medical Research Council Human Immunology Unit, National Institute for Health Research Biomedical Research Center, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
| | - Rachael Jarrett
- Medical Research Council Human Immunology Unit, National Institute for Health Research Biomedical Research Center, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
| | - Sumithra Subramaniam
- Medical Research Council Human Immunology Unit, National Institute for Health Research Biomedical Research Center, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
| | - Maryam Salimi
- Medical Research Council Human Immunology Unit, National Institute for Health Research Biomedical Research Center, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
| | - Danuta Gutowska-Owsiak
- Medical Research Council Human Immunology Unit, National Institute for Health Research Biomedical Research Center, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
| | - Yi-Ling Chen
- Medical Research Council Human Immunology Unit, National Institute for Health Research Biomedical Research Center, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
| | - Clare Hardman
- Medical Research Council Human Immunology Unit, National Institute for Health Research Biomedical Research Center, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
| | - Luzheng Xue
- Respiratory Medicine Unit, Nuffield Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
| | - Vincenzo Cerundolo
- Medical Research Council Human Immunology Unit, National Institute for Health Research Biomedical Research Center, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
| | - Graham Ogg
- Medical Research Council Human Immunology Unit, National Institute for Health Research Biomedical Research Center, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, England, UK
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14
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Leslie CC. Cytosolic phospholipase A₂: physiological function and role in disease. J Lipid Res 2015; 56:1386-402. [PMID: 25838312 DOI: 10.1194/jlr.r057588] [Citation(s) in RCA: 266] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Indexed: 02/06/2023] Open
Abstract
The group IV phospholipase A2 (PLA2) family is comprised of six intracellular enzymes (GIVA, -B, -C, -D, -E, and -F) commonly referred to as cytosolic PLA2 (cPLA2)α, -β, -γ, -δ, -ε, and -ζ. They contain a Ser-Asp catalytic dyad and all except cPLA2γ have a C2 domain, but differences in their catalytic activities and subcellular localization suggest unique regulation and function. With the exception of cPLA2α, the focus of this review, little is known about the in vivo function of group IV enzymes. cPLA2α catalyzes the hydrolysis of phospholipids to arachidonic acid and lysophospholipids that are precursors of numerous bioactive lipids. The regulation of cPLA2α is complex, involving transcriptional and posttranslational processes, particularly increases in calcium and phosphorylation. cPLA2α is a highly conserved widely expressed enzyme that promotes lipid mediator production in human and rodent cells from a variety of tissues. The diverse bioactive lipids produced as a result of cPLA2α activation regulate normal physiological processes and disease pathogenesis in many organ systems, as shown using cPLA2α KO mice. However, humans recently identified with cPLA2α deficiency exhibit more pronounced effects on health than observed in mice lacking cPLA2α, indicating that much remains to be learned about this interesting enzyme.
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Affiliation(s)
- Christina C Leslie
- Department of Pediatrics, National Jewish Health, Denver, CO 80206; and Departments of Pathology and Pharmacology, University of Colorado Denver, Aurora, CO 80045
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15
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Mironova GD, Saris NEL, Belosludtseva NV, Agafonov AV, Elantsev AB, Belosludtsev KN. Involvement of palmitate/Ca2+(Sr2+)-induced pore in the cycling of ions across the mitochondrial membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:488-95. [PMID: 25450352 DOI: 10.1016/j.bbamem.2014.10.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 09/23/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
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16
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Johansson C, Tumber A, Che K, Cain P, Nowak R, Gileadi C, Oppermann U. The roles of Jumonji-type oxygenases in human disease. Epigenomics 2014; 6:89-120. [PMID: 24579949 PMCID: PMC4233403 DOI: 10.2217/epi.13.79] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The iron- and 2-oxoglutarate-dependent oxygenases constitute a phylogenetically conserved class of enzymes that catalyze hydroxylation reactions in humans by acting on various types of substrates, including metabolic intermediates, amino acid residues in different proteins and various types of nucleic acids. The discovery of jumonji (Jmj), the founding member of a class of Jmj-type chromatin modifying enzymes and transcriptional regulators, has culminated in the discovery of several branches of histone lysine demethylases, with essential functions in regulating the epigenetic landscape of the chromatin environment. This work has now been considerably expanded into other aspects of epigenetic biology and includes the discovery of enzymatic steps required for methyl-cytosine demethylation as well as modification of RNA and ribosomal proteins. This overview aims to summarize the current knowledge on the human Jmj-type enzymes and their involvement in human pathological processes, including development, cancer, inflammation and metabolic diseases.
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Affiliation(s)
- Catrine Johansson
- Structural Genomics Consortium, University of Oxford, Old Road Campus, Roosevelt Drive, Headington, OX3 7DQ, UK
| | - Anthony Tumber
- Structural Genomics Consortium, University of Oxford, Old Road Campus, Roosevelt Drive, Headington, OX3 7DQ, UK
| | - KaHing Che
- Structural Genomics Consortium, University of Oxford, Old Road Campus, Roosevelt Drive, Headington, OX3 7DQ, UK
- Botnar Research Center, NIHR Oxford Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Oxford, OX3 7LD, UK
| | - Peter Cain
- Botnar Research Center, NIHR Oxford Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Oxford, OX3 7LD, UK
| | - Radoslaw Nowak
- Structural Genomics Consortium, University of Oxford, Old Road Campus, Roosevelt Drive, Headington, OX3 7DQ, UK
- Botnar Research Center, NIHR Oxford Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Oxford, OX3 7LD, UK
- Systems Approaches to Biomedical Sciences, Industrial Doctorate Center (SABS IDC) Oxford, UK
| | - Carina Gileadi
- Structural Genomics Consortium, University of Oxford, Old Road Campus, Roosevelt Drive, Headington, OX3 7DQ, UK
| | - Udo Oppermann
- Structural Genomics Consortium, University of Oxford, Old Road Campus, Roosevelt Drive, Headington, OX3 7DQ, UK
- Botnar Research Center, NIHR Oxford Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Oxford, OX3 7LD, UK
- Systems Approaches to Biomedical Sciences, Industrial Doctorate Center (SABS IDC) Oxford, UK
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Matsunami N, Hensel CH, Baird L, Stevens J, Otterud B, Leppert T, Varvil T, Hadley D, Glessner JT, Pellegrino R, Kim C, Thomas K, Wang F, Otieno FG, Ho K, Christensen GB, Li D, Prekeris R, Lambert CG, Hakonarson H, Leppert MF. Identification of rare DNA sequence variants in high-risk autism families and their prevalence in a large case/control population. Mol Autism 2014; 5:5. [PMID: 24467814 PMCID: PMC4098669 DOI: 10.1186/2040-2392-5-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 12/24/2013] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Genetics clearly plays a major role in the etiology of autism spectrum disorders (ASDs), but studies to date are only beginning to characterize the causal genetic variants responsible. Until recently, studies using multiple extended multi-generation families to identify ASD risk genes had not been undertaken. METHODS We identified haplotypes shared among individuals with ASDs in large multiplex families, followed by targeted DNA capture and sequencing to identify potential causal variants. We also assayed the prevalence of the identified variants in a large ASD case/control population. RESULTS We identified 584 non-conservative missense, nonsense, frameshift and splice site variants that might predispose to autism in our high-risk families. Eleven of these variants were observed to have odds ratios greater than 1.5 in a set of 1,541 unrelated children with autism and 5,785 controls. Three variants, in the RAB11FIP5, ABP1, and JMJD7-PLA2G4B genes, each were observed in a single case and not in any controls. These variants also were not seen in public sequence databases, suggesting that they may be rare causal ASD variants. Twenty-eight additional rare variants were observed only in high-risk ASD families. Collectively, these 39 variants identify 36 genes as ASD risk genes. Segregation of sequence variants and of copy number variants previously detected in these families reveals a complex pattern, with only a RAB11FIP5 variant segregating to all affected individuals in one two-generation pedigree. Some affected individuals were found to have multiple potential risk alleles, including sequence variants and copy number variants (CNVs), suggesting that the high incidence of autism in these families could be best explained by variants at multiple loci. CONCLUSIONS Our study is the first to use haplotype sharing to identify familial ASD risk loci. In total, we identified 39 variants in 36 genes that may confer a genetic risk of developing autism. The observation of 11 of these variants in unrelated ASD cases further supports their role as ASD risk variants.
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Affiliation(s)
- Nori Matsunami
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | | | - Lisa Baird
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Jeff Stevens
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Brith Otterud
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Tami Leppert
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Tena Varvil
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Dexter Hadley
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Joseph T Glessner
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Renata Pellegrino
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Cecilia Kim
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kelly Thomas
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Fengxiang Wang
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Frederick G Otieno
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Karen Ho
- Lineagen, Inc, Salt Lake City, UT, USA
| | | | - Dongying Li
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Rytis Prekeris
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | | | - Hakon Hakonarson
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Mark F Leppert
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
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18
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Capestrano M, Mariggio S, Perinetti G, Egorova AV, Iacobacci S, Santoro M, Di Pentima A, Iurisci C, Egorov MV, Di Tullio G, Buccione R, Luini A, Polishchuk RS. Cytosolic phospholipase A₂ε drives recycling through the clathrin-independent endocytic route. J Cell Sci 2014; 127:977-93. [PMID: 24413173 DOI: 10.1242/jcs.136598] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Previous studies have demonstrated that membrane tubule-mediated transport events in biosynthetic and endocytic routes require phospholipase A2 (PLA2) activity. Here, we show that cytosolic phospholipase A2ε (cPLA2ε, also known as PLA2G4E) is targeted to the membrane compartments of the clathrin-independent endocytic route through a C-terminal stretch of positively charged amino acids, which allows the enzyme to interact with phosphoinositide lipids [especially PI(4,5)P2] that are enriched in clathrin-independent endosomes. Ablation of cPLA2ε suppressed the formation of tubular elements that carry internalized clathrin-independent cargoes, such as MHC-I, CD147 and CD55, back to the cell surface and, therefore, caused their intracellular retention. The ability of cPLA2ε to support recycling through tubule formation relies on the catalytic activity of the enzyme, because the inactive cPLA2ε(S420A) mutant was not able to recover either tubule growth or transport from clathrin-independent endosomes. Taken together, our findings indicate that cPLA2ε is a new important regulator of trafficking processes within the clathrin-independent endocytic and recycling route. The affinity of cPLA2ε for this pathway supports a new hypothesis that different PLA2 enzymes use selective targeting mechanisms to regulate tubule formation locally during specific trafficking steps in the secretory and/or endocytic systems.
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19
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Kelemen O, Convertini P, Zhang Z, Wen Y, Shen M, Falaleeva M, Stamm S. Function of alternative splicing. Gene 2013; 514:1-30. [PMID: 22909801 PMCID: PMC5632952 DOI: 10.1016/j.gene.2012.07.083] [Citation(s) in RCA: 512] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/21/2012] [Accepted: 07/30/2012] [Indexed: 12/15/2022]
Abstract
Almost all polymerase II transcripts undergo alternative pre-mRNA splicing. Here, we review the functions of alternative splicing events that have been experimentally determined. The overall function of alternative splicing is to increase the diversity of mRNAs expressed from the genome. Alternative splicing changes proteins encoded by mRNAs, which has profound functional effects. Experimental analysis of these protein isoforms showed that alternative splicing regulates binding between proteins, between proteins and nucleic acids as well as between proteins and membranes. Alternative splicing regulates the localization of proteins, their enzymatic properties and their interaction with ligands. In most cases, changes caused by individual splicing isoforms are small. However, cells typically coordinate numerous changes in 'splicing programs', which can have strong effects on cell proliferation, cell survival and properties of the nervous system. Due to its widespread usage and molecular versatility, alternative splicing emerges as a central element in gene regulation that interferes with almost every biological function analyzed.
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Affiliation(s)
- Olga Kelemen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Paolo Convertini
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zhaiyi Zhang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Yuan Wen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Manli Shen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Marina Falaleeva
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Stefan Stamm
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
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20
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Jabůrek M, Ježek J, Zelenka J, Ježek P. Antioxidant activity by a synergy of redox-sensitive mitochondrial phospholipase A2 and uncoupling protein-2 in lung and spleen. Int J Biochem Cell Biol 2013; 45:816-25. [PMID: 23354121 DOI: 10.1016/j.biocel.2013.01.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 01/11/2013] [Accepted: 01/14/2013] [Indexed: 12/24/2022]
Abstract
Mitochondrial uncoupling protein-2 (UCP2) has been suggested to participate in the attenuation of the reactive oxygen species production, but the mechanism of action and the physiological significance of UCP2 activity remain controversial. Here we tested the hypothesis that UCP2 provides feedback downregulation of oxidative stress in vivo via synergy with an H2O2-activated mitochondrial calcium-independent phospholipase A2 (mt-iPLA2). Tert-butylhydroperoxide or H2O2 induced free fatty acid release from mitochondrial membranes as detected by gas chromatography/mass spectrometry, which was inhibited by r-bromoenol lactone (r-BEL) but not by its stereoisomer s-BEL, suggesting participation of mt-iPLA2γ isoform. Tert-butylhydroperoxide or H2O2 also induced increase in respiration and decrease in mitochondrial membrane potential in lung and spleen mitochondria from control but not UCP2-knockout mice. These data suggest that mt-iPLA2γ-dependent release of free fatty acids promotes UCP2-dependent uncoupling. Upon such uncoupling, mitochondrial superoxide formation decreased instantly also in the s-BEL presence, but not when mt-iPLA2 was blocked by R-BEL and not in mitochondria from UCP2-knockout mice. Mt-iPLA2γ was alternatively activated by H2O2 produced probably in conjunction with the electron-transferring flavoprotein:ubiquinone oxidoreductase (ETFQOR), acting in fatty acid β-oxidation. Palmitoyl-d,l-carnitine addition to mouse lung mitochondria, respiring with succinate plus rotenone, caused a respiration increase that was sensitive to r-BEL and insensitive to s-BEL. We thus demonstrate for the first time that UCP2, functional due to fatty acids released by redox-activated mt-iPLA2γ, suppresses mitochondrial superoxide production by its uncoupling action. In conclusion, H2O2-activated mt-iPLA2γ and UCP2 act in concert to protect against oxidative stress.
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Affiliation(s)
- Martin Jabůrek
- Department of Membrane Transport Biophysics, No. 75, Institute of Physiology, Academy of Sciences, Vídeňská 1083, Prague 14220, Czech Republic
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21
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Moon SH, Jenkins CM, Liu X, Guan S, Mancuso DJ, Gross RW. Activation of mitochondrial calcium-independent phospholipase A2γ (iPLA2γ) by divalent cations mediating arachidonate release and production of downstream eicosanoids. J Biol Chem 2012; 287:14880-95. [PMID: 22389508 DOI: 10.1074/jbc.m111.336776] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Calcium-independent phospholipase A(2)γ (iPLA(2)γ) (PNPLA8) is the predominant phospholipase activity in mammalian mitochondria. However, the chemical mechanisms that regulate its activity are unknown. Here, we utilize iPLA(2)γ gain of function and loss of function genetic models to demonstrate the robust activation of iPLA(2)γ in murine myocardial mitochondria by Ca(2+) or Mg(2+) ions. Calcium ion stimulated the production of 2-arachidonoyl-lysophosphatidylcholine (2-AA-LPC) from 1-palmitoyl-2-[(14)C]arachidonoyl-sn-glycero-3-phosphocholine during incubations with wild-type heart mitochondrial homogenates. Furthermore, incubation of mitochondrial homogenates from transgenic myocardium expressing iPLA(2)γ resulted in 13- and 25-fold increases in the initial rate of radiolabeled 2-AA-LPC and arachidonic acid (AA) production, respectively, in the presence of calcium ion. Mass spectrometric analysis of the products of calcium-activated hydrolysis of endogenous mitochondrial phospholipids in transgenic iPLA(2)γ mitochondria revealed the robust production of AA, 2-AA-LPC, and 2-docosahexaenoyl-LPC that was over 10-fold greater than wild-type mitochondria. The mechanism-based inhibitor (R)-(E)-6-(bromomethylene)-3-(1-naphthalenyl)-2H-tetrahydropyran-2-one (BEL) (iPLA(2)γ selective), but not its enantiomer, (S)-BEL (iPLA(2)β selective) or pyrrolidine (cytosolic PLA(2)α selective), markedly attenuated Ca(2+)-dependent fatty acid release and polyunsaturated LPC production. Moreover, Ca(2+)-induced iPLA(2)γ activation was accompanied by the production of downstream eicosanoid metabolites that were nearly completely ablated by (R)-BEL or by genetic ablation of iPLA(2)γ. Intriguingly, Ca(2+)-induced iPLA(2)γ activation was completely inhibited by long-chain acyl-CoA (IC(50) ∼20 μm) as well as by a nonhydrolyzable acyl-CoA thioether analog. Collectively, these results demonstrate that mitochondrial iPLA(2)γ is activated by divalent cations and inhibited by acyl-CoA modulating the generation of biologically active metabolites that regulate mitochondrial bioenergetic and signaling functions.
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Affiliation(s)
- Sung Ho Moon
- Department of Medicine, Division of Bioorganic Chemistry and Molecular Pharmacology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Abstract
Phospholipids are present in all living organisms. They are a major component of all biological membranes, along with glycolipids and cholesterol. Enzymes aimed at cleaving the various bonds in phospholipids, namely phospholipases, are consequently widespread in nature, playing very diverse roles from aggression in snake venom to signal transduction, lipid mediators production, and digestion in humans. Although all phospholipases target phospholipids as substrates, they vary in the site of action on the phospholipids molecules, physiological function, mode of action, and their regulation. Significant studies on phospholipases characterization, physiological role, and industrial potential have been conducted worldwide. Some of them have been directed for biotechnological advances, such as gene discovery and functional enhancement by protein engineering. Others reported phospholipases as virulence factors and major causes of pathophysiological effects. In this introductory chapter, we provide brief details of different phospholipases.
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Affiliation(s)
- Ahmed Aloulou
- National School of Engineers of Sfax, University of Sfax, Sfax, Tunisia.
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23
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Dennis EA, Cao J, Hsu YH, Magrioti V, Kokotos G. Phospholipase A2 enzymes: physical structure, biological function, disease implication, chemical inhibition, and therapeutic intervention. Chem Rev 2011; 111:6130-85. [PMID: 21910409 PMCID: PMC3196595 DOI: 10.1021/cr200085w] [Citation(s) in RCA: 804] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Edward A. Dennis
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Jian Cao
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Yuan-Hao Hsu
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Victoria Magrioti
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
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Long JZ, Cravatt BF. The metabolic serine hydrolases and their functions in mammalian physiology and disease. Chem Rev 2011; 111:6022-63. [PMID: 21696217 DOI: 10.1021/cr200075y] [Citation(s) in RCA: 299] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jonathan Z Long
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
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25
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Affiliation(s)
- Motonao Nakamura
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Hongo, Tokyo, Japan.
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26
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Laus MN, Soccio M, Trono D, Liberatore MT, Pastore D. Activation of the plant mitochondrial potassium channel by free fatty acids and acyl-CoA esters: a possible defence mechanism in the response to hyperosmotic stress. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:141-54. [PMID: 20801915 DOI: 10.1093/jxb/erq256] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The effect of free fatty acids (FFAs) and acyl-CoA esters on K(+) uptake was studied in mitochondria isolated from durum wheat (Triticum durum Desf.), a species that has adapted well to the semi-arid Mediterranean area and possessing a highly active mitochondrial ATP-sensitive K(+) channel (PmitoK(ATP)), that may confer resistance to environmental stresses. This was made by swelling experiments in KCl solution under experimental conditions in which PmitoK(ATP) activity was monitored. Linoleate and other FFAs (laurate, palmitate, stearate, palmitoleate, oleate, arachidonate, and the non-physiological 1-undecanesulphonate and 5-phenylvalerate), used at a concentration (10 μM) unable to damage membranes of isolated mitochondria, stimulated K(+) uptake by about 2-4-fold. Acyl-CoAs also promoted K(+) transport to a much larger extent with respect to FFAs (about 5-12-fold). In a different experimental system based on safranin O fluorescence measurements, the dissipation of electrical membrane potential induced by K(+) uptake via PmitoK(ATP) was found to increase in the presence of 5-phenylvalerate and palmitoyl-CoA, both unable to elicit the activity of the Plant Uncoupling Protein. This result suggests a direct activation of PmitoK(ATP). Stimulation of K(+) transport by FFAs/acyl-CoAs resulted in a widespread phenomenon in plant mitochondria from different mono/dicotyledonous species (bread wheat, barley, triticale, maize, lentil, pea, and topinambur) and from different organs (root, tuber, leaf, and shoot). Finally, an increase in mitochondrial FFAs up to a content of 50 nmol mg(-1) protein, which was able to activate PmitoK(ATP) strongly, was observed under hyperosmotic stress conditions. Since PmitoK(ATP) may act against environmental/oxidative stress, its activation by FFAs/acyl-CoAs is proposed to represent a physiological defence mechanism.
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Affiliation(s)
- Maura N Laus
- Dipartimento di Scienze Agro-ambientali, Chimica e Difesa Vegetale, Facoltà di Agraria, Università degli Studi di Foggia, Via Napoli, 25-71122 Foggia, Italy
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Murakami M, Taketomi Y, Miki Y, Sato H, Hirabayashi T, Yamamoto K. Recent progress in phospholipase A₂ research: from cells to animals to humans. Prog Lipid Res 2010; 50:152-92. [PMID: 21185866 DOI: 10.1016/j.plipres.2010.12.001] [Citation(s) in RCA: 368] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian genomes encode genes for more than 30 phospholipase A₂s (PLA₂s) or related enzymes, which are subdivided into several classes including low-molecular-weight secreted PLA₂s (sPLA₂s), Ca²+-dependent cytosolic PLA₂s (cPLA₂s), Ca²+-independent PLA₂s (iPLA₂s), platelet-activating factor acetylhydrolases (PAF-AHs), lysosomal PLA₂s, and a recently identified adipose-specific PLA. Of these, the intracellular cPLA₂ and iPLA₂ families and the extracellular sPLA₂ family are recognized as the "big three". From a general viewpoint, cPLA₂α (the prototypic cPLA₂ plays a major role in the initiation of arachidonic acid metabolism, the iPLA₂ family contributes to membrane homeostasis and energy metabolism, and the sPLA₂ family affects various biological events by modulating the extracellular phospholipid milieus. The cPLA₂ family evolved along with eicosanoid receptors when vertebrates first appeared, whereas the diverse branching of the iPLA₂ and sPLA₂ families during earlier eukaryote development suggests that they play fundamental roles in life-related processes. During the past decade, data concerning the unexplored roles of various PLA₂ enzymes in pathophysiology have emerged on the basis of studies using knockout and transgenic mice, the use of specific inhibitors, and information obtained from analysis of human diseases caused by mutations in PLA₂ genes. This review focuses on current understanding of the emerging biological functions of PLA₂s and related enzymes.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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28
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Ghomashchi F, Naika GS, Bollinger JG, Aloulou A, Lehr M, Leslie CC, Gelb MH. Interfacial kinetic and binding properties of mammalian group IVB phospholipase A2 (cPLA2beta) and comparison with the other cPLA2 isoforms. J Biol Chem 2010; 285:36100-11. [PMID: 20705608 DOI: 10.1074/jbc.m110.165647] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cytosolic (group IV) phospholipase A(2) (cPLA(2)s) family contains six members. We have prepared recombinant proteins for human α, mouse β, human γ, human δ, human ε, and mouse ζ cPLA(2)s and have studied their interfacial kinetic and binding properties in vitro. Mouse cPLA(2)β action on phosphatidylcholine vesicles is activated by anionic phosphoinositides and cardiolipin but displays a requirement for Ca(2+) only in the presence of cardiolipin. This activation pattern is explained by the effects of anionic phospholipids and Ca(2+) on the interfacial binding of mouse cPLA(2)β and its C2 domain to vesicles. Ca(2+)-dependent binding of mouse cPLA(2)β to cardiolipin-containing vesicles requires a patch of basic residues near the Ca(2+)-binding surface loops of the C2 domain, but binding to phosphoinositide-containing vesicles does not depend on any specific cluster of basic residues. Human cPLA(2)δ also displays Ca(2+)- and cardiolipin-enhanced interfacial binding and activity. The lysophospholipase, phospholipase A(1), and phospholipase A(2) activities of the full set of mammalian cPLA(2)s were quantified. The relative level of these activities is very different among the isoforms, and human cPLA(2)δ stands out as having relatively high phospholipase A(1) activity. We also tested the susceptibility of all cPLA(2) family members to a panel of previously reported inhibitors of human cPLA(2)α and analogs of these compounds. This led to the discovery of a potent and selective inhibitor of mouse cPLA(2)β. These in vitro studies help determine the regulation and function of the cPLA(2) family members.
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Affiliation(s)
- Farideh Ghomashchi
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
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L-carnitine is essential to beta-oxidation of quarried fatty acid from mitochondrial membrane by PLA(2). Mol Cell Biochem 2010; 342:95-100. [PMID: 20443048 DOI: 10.1007/s11010-010-0472-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Accepted: 04/17/2010] [Indexed: 12/19/2022]
Abstract
Mitochondrial beta-oxidation is an important system involved in the energy production of various cells. In this system, the function of L-carnitine is essential for the uptake of fatty acids to mitochondria. However, it is unclear whether or not endogenous respiration, ADP-induced O(2) consumption without substrates, is caused by L-carnitine treatment. In this study, we investigated whether L-carnitine is essential to the beta-oxidation of quarried fatty acids from the mitochondrial membrane by phospholipase A(2) (PLA(2)) using isolated mitochondria from the liver of rats. Intact mitochondria were incubated in a medium containing Pi, CoA and L-carnitine. The effect of L-carnitine treatment on ADP-induced mitochondrial respiration was observed without exogenous respiratory substrate. Increase in mitochondrial respiration was induced by treatment with L-carnitine in a concentration-dependent manner. Treatment with rotenone, a complex I blocker, completely inhibited ADP-induced oxygen consumption even in the presence of L-carnitine. Moreover, the L-carnitine dependent ADP-induced mitochondrial oxygen consumption did not increase when PLA(2) inhibitors were treated before ADP treatment. The L-carnitine-dependent ADP-induced oxygen consumption did contribute to ATP productions but not heat generation via an uncoupling system. These results suggest that L-carnitine might be essential to the beta-oxidation of quarried fatty acids from the mitochondrial membrane by PLA(2).
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Takaya K, Higuchi Y, Kitamoto K, Arioka M. A cytosolic phospholipase A2-like protein in the filamentous fungusAspergillus oryzaelocalizes to the intramembrane space of the mitochondria. FEMS Microbiol Lett 2009; 301:201-9. [DOI: 10.1111/j.1574-6968.2009.01818.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Pietro ES, Capestrano M, Polishchuk EV, DiPentima A, Trucco A, Zizza P, Mariggiò S, Pulvirenti T, Sallese M, Tete S, Mironov AA, Leslie CC, Corda D, Luini A, Polishchuk RS. Group IV phospholipase A(2)alpha controls the formation of inter-cisternal continuities involved in intra-Golgi transport. PLoS Biol 2009; 7:e1000194. [PMID: 19753100 PMCID: PMC2732982 DOI: 10.1371/journal.pbio.1000194] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Accepted: 07/31/2009] [Indexed: 11/18/2022] Open
Abstract
The organization of intra-Golgi trafficking and the nature of the transport intermediates involved (e.g., vesicles, tubules, or tubular continuities) remain incompletely understood. It was recently shown that successive cisternae in the Golgi stack are interconnected by membrane tubules that form during the arrival of transport carriers from the endoplasmic reticulum. Here, we examine the mechanisms of generation and the function of these tubules. In principle, tubule formation might depend on several protein- and/or lipid-based mechanisms. Among the latter, we have studied the phospholipase A(2) (PLA(2))-mediated generation of wedge-shaped lysolipids, with the resulting local positive membrane curvature. We show that the arrival of cargo at the Golgi complex induces the recruitment of Group IVA Ca(2+)-dependent, cytosolic PLA(2) (cPLA(2)alpha) onto the Golgi complex itself, and that this cPLA(2)alpha is required for the formation of the traffic-dependent intercisternal tubules and for intra-Golgi transport. In contrast, silencing of cPLA(2)alpha has no inhibitory effects on peri-Golgi vesicles. These findings identify cPLA(2)alpha as the first component of the machinery that is responsible for the formation of intercisternal tubular continuities and support a role for these continuities in transport through the Golgi complex.
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Affiliation(s)
- Enrica San Pietro
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | | | - Elena V. Polishchuk
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Alessio DiPentima
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Alvar Trucco
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Pasquale Zizza
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Stefania Mariggiò
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Teodoro Pulvirenti
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Michele Sallese
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Stefano Tete
- Department of Oral Sciences, University “G. D'Annunzio”, Chieti, Italy
| | - Alexander A. Mironov
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Christina C. Leslie
- Department of Pediatrics, National Jewish Medical and Research Center, Denver, Colorado, United States of America
| | - Daniela Corda
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
| | - Alberto Luini
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
- Telethon Institute of Genetics and Medicine, Naples, Italy
- * E-mail: (AL); (RSP)
| | - Roman S. Polishchuk
- Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Chieti, Italy
- Telethon Institute of Genetics and Medicine, Naples, Italy
- * E-mail: (AL); (RSP)
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Kitsiouli E, Nakos G, Lekka ME. Phospholipase A2 subclasses in acute respiratory distress syndrome. Biochim Biophys Acta Mol Basis Dis 2009; 1792:941-53. [PMID: 19577642 DOI: 10.1016/j.bbadis.2009.06.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 06/25/2009] [Accepted: 06/25/2009] [Indexed: 01/12/2023]
Abstract
Phospholipases A2 (PLA2) catalyse the cleavage of fatty acids esterified at the sn-2 position of glycerophospholipids. In acute lung injury-acute respiratory distress syndrome (ALI-ARDS) several distinct isoenzymes appear in lung cells and fluid. Some are capable to trigger molecular events leading to enhanced inflammation and lung damage and others have a role in lung surfactant recycling preserving lung function: Secreted forms (groups sPLA2-IIA, -V, -X) can directly hydrolyze surfactant phospholipids. Cytosolic PLA2 (cPLA2-IVA) requiring Ca2+ has a preference for arachidonate, the precursor of eicosanoids which participate in the inflammatory response in the lung. Ca(2+)-independent intracellular PLA2s (iPLA2) take part in surfactant phospholipids turnover within alveolar cells. Acidic Ca(2+)-independent PLA2 (aiPLA2), of lysosomal origin, has additionally antioxidant properties, (peroxiredoxin VI activity), and participates in the formation of dipalmitoyl-phosphatidylcholine in lung surfactant. PAF-AH degrades PAF, a potent mediator of inflammation, and oxidatively fragmented phospholipids but also leads to toxic metabolites. Therefore, the regulation of PLA2 isoforms could be a valuable approach for ARDS treatment.
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Affiliation(s)
- Eirini Kitsiouli
- Department of Biological Applications and Technologies, School of Sciences and Technologies, University of Ioannina, Greece
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Schug ZT, Gottlieb E. Cardiolipin acts as a mitochondrial signalling platform to launch apoptosis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:2022-31. [PMID: 19450542 DOI: 10.1016/j.bbamem.2009.05.004] [Citation(s) in RCA: 197] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2008] [Revised: 05/06/2009] [Accepted: 05/08/2009] [Indexed: 11/16/2022]
Abstract
Cardiolipin (CL) is a unique anionic phospholipid specific to the mitochondria. CL influences the activity of electron transport chain enzyme complexes as well as members of the Bcl-2 family. Interactions between Bcl-2 family members and other pro-apoptotic enzymes have been shown to be crucial for the transduction of the apoptotic signalling cascades during programmed cell death. Targeting of tBid to the mitochondria, which is necessary for Bax/Bak oligomerization and cristae remodelling, is dependent on the exposure of CL at contact sites between the inner and outer mitochondrial membranes. Also, the mobilization of cytochrome c, another key apoptotic event, is tightly regulated by the oxidative state of cardiolipin. Moreover, CL has been shown to be essential for translocation and autoprocessing of caspase-8 on the mitochondria after death receptor stimulation. Deficiencies in CL inhibit the formation of tBid and prevent apoptosis by removing an essential activation platform for the autoprocessing of caspase-8. It is now apparent that CL acts as a crucial signalling platform from which it orchestrates apoptosis by integrating signals from a variety of death inducing proteins.
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Affiliation(s)
- Zachary T Schug
- Cancer Research UK, The Beatson Institute for Cancer Research, Glasgow, G61 1BD, UK
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Shimizu T. Lipid mediators in health and disease: enzymes and receptors as therapeutic targets for the regulation of immunity and inflammation. Annu Rev Pharmacol Toxicol 2009; 49:123-50. [PMID: 18834304 DOI: 10.1146/annurev.pharmtox.011008.145616] [Citation(s) in RCA: 430] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Prostaglandins, leukotrienes, platelet-activating factor, lysophosphatidic acid, sphingosine 1-phosphate, and endocannabinoids, collectively referred to as lipid mediators, play pivotal roles in immune regulation and self-defense, and in the maintenance of homeostasis in living systems. They are produced by multistep enzymatic pathways, which are initiated by the de-esterification of membrane phospholipids by phospholipase A2s or sphingo-myelinase. Lipid mediators exert their biological effects by binding to cognate receptors, which are members of the G protein-coupled receptor superfamily. The synthesis of the lipid mediators and subsequent induction of receptor activity is tightly regulated under normal physiological conditions, and enzyme and/or receptor dysfunction can lead to a variety of disease conditions. Thus, the manipulation of lipid mediator signaling, through either enzyme inhibitors or receptor antagonists and agonists, has great potential as a therapeutic approach to disease. In this review, I summarize our current state of knowledge of the synthesis of lipid mediators and the function of their cognate receptors, and discuss the effects of genetic or pharmacological ablation of enzyme or receptor function on various pathophysiological processes.
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Affiliation(s)
- Takao Shimizu
- Department of Biochemistry and Molecular Biology, The University of Tokyo, Tokyo 113-0033, Japan.
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Yasuda D, Okuno T, Yokomizo T, Hori T, Hirota N, Hashidate T, Miyano M, Shimizu T, Nakamura M. Helix 8 of leukotriene B4type‐2 receptor is required for the folding to pass the quality control in the endoplasmic reticulum. FASEB J 2009; 23:1470-81. [DOI: 10.1096/fj.08-125385] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Daisuke Yasuda
- Department of Biochemistry and Molecular BiologyFaculty of MedicineThe University of TokyoTokyoJapan
| | - Toshiaki Okuno
- Department of Medical BiochemistryGraduate School of Medical SciencesKyushu UniversityFukuokaJapan
| | - Takehiko Yokomizo
- Department of Medical BiochemistryGraduate School of Medical SciencesKyushu UniversityFukuokaJapan
| | - Tetsuya Hori
- Structural Biophysics LaboratoryRIKEN Harima Institute at SpringHyogo8Japan
| | - Nobuaki Hirota
- Department of Biochemistry and Molecular BiologyFaculty of MedicineThe University of TokyoTokyoJapan
| | - Tomomi Hashidate
- Department of Biochemistry and Molecular BiologyFaculty of MedicineThe University of TokyoTokyoJapan
| | - Masashi Miyano
- Structural Biophysics LaboratoryRIKEN Harima Institute at SpringHyogo8Japan
| | - Takao Shimizu
- Department of Biochemistry and Molecular BiologyFaculty of MedicineThe University of TokyoTokyoJapan
| | - Motonao Nakamura
- Department of Biochemistry and Molecular BiologyFaculty of MedicineThe University of TokyoTokyoJapan
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Multiple roles of phospholipase A2 during lung infection and inflammation. Infect Immun 2008; 76:2259-72. [PMID: 18411286 DOI: 10.1128/iai.00059-08] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Schlame M. Cardiolipin synthesis for the assembly of bacterial and mitochondrial membranes. J Lipid Res 2007; 49:1607-20. [PMID: 18077827 DOI: 10.1194/jlr.r700018-jlr200] [Citation(s) in RCA: 292] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In this article, the formation of prokaryotic and eukaryotic cardiolipin is reviewed in light of its biological function. I begin with a detailed account of the structure of cardiolipin, its stereochemistry, and the resulting physical properties, and I present structural analogs of cardiolipin that occur in some organisms. Then I continue to discuss i) the de novo formation of cardiolipin, ii) its acyl remodeling, iii) the assembly of cardiolipin into biological membranes, and iv) the degradation of cardiolipin, which may be involved in apoptosis and mitochondrial fusion. Thus, this article covers the entire metabolic cycle of this unique phospholipid. It is shown that mitochondria produce cardiolipin species with a high degree of structural uniformity and molecular symmetry, among which there is often a dominant form with four identical acyl chains. The subsequent assembly of cardiolipin into functional membranes is largely unknown, but the analysis of crystal structures of membrane proteins has revealed a first glimpse into the underlying principles of cardiolipin-protein interactions. Disturbances of cardiolipin metabolism are crucial in the pathophysiology of human Barth syndrome and perhaps also play a role in diabetes and ischemic heart disease.
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Affiliation(s)
- Michael Schlame
- Department of Anesthesiology and Cell Biology, New York University School of Medicine, New York, NY 10016, USA.
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Ghosh M, Loper R, Ghomashchi F, Tucker DE, Bonventre JV, Gelb MH, Leslie CC. Function, activity, and membrane targeting of cytosolic phospholipase A(2)zeta in mouse lung fibroblasts. J Biol Chem 2007; 282:11676-86. [PMID: 17293613 PMCID: PMC2678067 DOI: 10.1074/jbc.m608458200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Group IVA cytosolic phospholipase A(2) (cPLA(2)alpha) initiates eicosanoid production; however, this pathway is not completely ablated in cPLA(2)alpha(-/-) lung fibroblasts stimulated with A23187 or serum. cPLA(2)alpha(+/+) fibroblasts preferentially released arachidonic acid, but A23187-stimulated cPLA(2)alpha(-/-) fibroblasts nonspecifically released multiple fatty acids. Arachidonic acid release from cPLA(2) alpha(-/-) fibroblasts was inhibited by the cPLA(2)alpha inhibitors pyrrolidine-2 (IC(50), 0.03 microM) and Wyeth-1 (IC(50), 0.1 microM), implicating another C2 domain-containing group IV PLA(2). cPLA(2) alpha(-/-) fibroblasts contain cPLA(2)beta and cPLA(2)zeta but not cPLA(2)epsilon or cPLA(2)delta. Purified cPLA(2)zeta exhibited much higher lysophospholipase and PLA(2) activity than cPLA(2)beta and was potently inhibited by pyrrolidine-2 and Wyeth-1, which did not inhibit cPLA(2)beta. In contrast to cPLA(2)beta, cPLA(2)zeta expressed in Sf9 cells mediated A23187-induced arachidonic acid release, which was inhibited by pyrrolidine-2 and Wyeth-1. cPLA(2)zeta exhibits specific activity, inhibitor sensitivity, and low micromolar calcium dependence similar to cPLA(2)alpha and has been identified as the PLA(2) responsible for calcium-induced fatty acid release and prostaglandin E(2) production from cPLA(2) alpha(-/-) lung fibroblasts. In response to ionomycin, EGFP-cPLA(2)zeta translocated to ruffles and dynamic vesicular structures, whereas EGFP-cPLA(2)alpha translocated to the Golgi and endoplasmic reticulum, suggesting distinct mechanisms of regulation for the two enzymes.
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Affiliation(s)
- Moumita Ghosh
- Program in Cell Biology, Department of Pediatrics, National Jewish Medical and Research Center, Denver, Colorado 80206
| | - Robyn Loper
- Program in Cell Biology, Department of Pediatrics, National Jewish Medical and Research Center, Denver, Colorado 80206
| | - Farideh Ghomashchi
- Departments of Chemistry and Biochemistry, University of Washington, Seattle, Washington 98195
| | - Dawn E. Tucker
- Program in Cell Biology, Department of Pediatrics, National Jewish Medical and Research Center, Denver, Colorado 80206
| | | | - Michael H. Gelb
- Departments of Chemistry and Biochemistry, University of Washington, Seattle, Washington 98195
| | - Christina C. Leslie
- Program in Cell Biology, Department of Pediatrics, National Jewish Medical and Research Center, Denver, Colorado 80206
- Departments of Pathology and Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
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Kinsey GR, McHowat J, Patrick KS, Schnellmann RG. Role of Ca2+-independent phospholipase A2gamma in Ca2+-induced mitochondrial permeability transition. J Pharmacol Exp Ther 2007; 321:707-15. [PMID: 17312185 DOI: 10.1124/jpet.107.119545] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Our laboratory previously demonstrated Ca2+-independent phospholipase A2gamma (iPLA2gamma) is localized to mitochondria and that iPLA2 inhibition blocks cisplatin-induced caspase-mediated apoptosis. Whereas the mitochondrial permeability transition (MPT) is a key control point for apoptosis, the role of mitochondrial iPLA2gamma in MPT has not been established. In the present study, we addressed this issue. Ca2+-induced renal cortex mitochondrial (RCM) swelling was blocked by the MPT inhibitor cyclosporine A. The R-isomer of bromoenol lactone (R-BEL), which enantiospecifically inhibits iPLA2gamma, inhibited Ca2+-induced RCM MPT, whereas S-BEL (negative control) had no effect. Ca2+ treatment resulted in a significant increase in free arachidonic acid (AA) (>50 microM) in the RCM suspension that was blocked by pretreatment with BEL. No increases in free myristic, palmitic, stearic, oleic, linoleic, or docosahexaenoic acid were detected after Ca2+ treatment. The addition of AA (18 microM) to Ca2+-treated RCM with inhibited iPLA2gamma activity restored MPT. We also determined that RCM iPLA2gamma displays higher activity against plasmenylcholine with AA in the sn-2 position than oleic acid. Ca2+ exposure significantly increased RCM iPLA2gamma activity; however, the Ca2+-induced activation of iPLA2gamma was not the result of mitochondrial membrane potential dissipation, opening of the MPT pore, or mitochondrial swelling. Taken together these findings provide strong evidence that Ca2+-induced RCM MPT is mediated by iPLA2gamma-catalyzed AA liberation.
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Affiliation(s)
- Gilbert R Kinsey
- Medical University of South Carolina, Department of Pharmaceutical Sciences, 280 Calhoun St., Charleston, SC 29425, USA
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Kita Y, Ohto T, Uozumi N, Shimizu T. Biochemical properties and pathophysiological roles of cytosolic phospholipase A2s. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:1317-22. [PMID: 16962823 DOI: 10.1016/j.bbalip.2006.08.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2006] [Revised: 07/25/2006] [Accepted: 08/01/2006] [Indexed: 10/24/2022]
Abstract
Phospholipase A(2) (PLA(2)) (EC 3.1.1.4) catalyzes hydrolysis of the sn-2 ester bond of glycerophospholipids. The enzyme is essential for the production of two classes of lipid mediators, fatty acid metabolites and lysophospholipid-related lipids, as well as being involved in the remodeling of membrane phospholipids. Among many mammalian PLA(2)s, cytosolic PLA(2)alpha (cPLA(2)alpha) plays a critical role in various physiological and pathophysiological conditions through generating lipid mediators. Here, we summarize the in vivo significance of cPLA(2)alpha, revealed from the phenotypes of cPLA(2)alpha-null mice, and properties of newly discovered cPLA(2) family enzymes. We also briefly introduce a quantitative lipidomics strategy using liquid chromatography-mass spectrometry, a powerful tool for the comprehensive analysis of lipid mediators.
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Affiliation(s)
- Yoshihiro Kita
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
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