1
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Decker ST, Funai K. Mitochondrial membrane lipids in the regulation of bioenergetic flux. Cell Metab 2024; 36:1963-1978. [PMID: 39178855 PMCID: PMC11374467 DOI: 10.1016/j.cmet.2024.07.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 06/12/2024] [Accepted: 07/31/2024] [Indexed: 08/26/2024]
Abstract
Oxidative phosphorylation (OXPHOS) occurs through and across the inner mitochondrial membrane (IMM). Mitochondrial membranes contain a distinct lipid composition, aided by lipid biosynthetic machinery localized in the IMM and class-specific lipid transporters that limit lipid traffic in and out of mitochondria. This unique lipid composition appears to be essential for functions of mitochondria, particularly OXPHOS, by its effects on direct lipid-to-protein interactions, membrane properties, and cristae ultrastructure. This review highlights the biological significance of mitochondrial lipids, with a particular spotlight on the role of lipids in mitochondrial bioenergetics. We describe pathways for the biosynthesis of mitochondrial lipids and provide evidence for their roles in physiology, their implications in human disease, and the mechanisms by which they regulate mitochondrial bioenergetics.
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Affiliation(s)
- Stephen Thomas Decker
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
| | - Katsuhiko Funai
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA.
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2
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Li Y, Zhang J, Zhang Y, Zhang B, Wang Z, Wu C, Zhou Z, Chang X. Integrated metabolomic and transcriptomic analysis reveals perturbed glycerophospholipid metabolism in mouse neural stem cells exposed to cadmium. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 264:115411. [PMID: 37660531 DOI: 10.1016/j.ecoenv.2023.115411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/29/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023]
Abstract
Cadmium (Cd) is a ubiquitous heavy metal with neurotoxicity. Our previous study reported that Cd could inhibit the proliferation of mouse neural stem cells (mNSCs). However, the underlying mechanisms are obscure. In recent years, the rapid growth of multi-omics techniques enables us to explore the cellular responses that occurred after toxicant exposure at the molecular level. In this study, we used a combination of metabolomics and transcriptomics approaches to investigate the effects of exposure to Cd on mNSCs. After treatment with Cd, the metabolites and transcripts in mNSCs changed significantly with 110 differentially expressed metabolites and 2135 differentially expressed genes identified, respectively. The altered metabolites were mainly involved in glycerophospholipid metabolism, arginine and proline metabolism, arginine biosynthesis, glyoxylate and dicarboxylate metabolism. Meanwhile, the transcriptomic data demonstrated perturbed membrane function and signal transduction. Furthermore, integrated analysis of metabolomic and transcriptomic data suggested that glycerophospholipid metabolism might be the major metabolic pathway affected by Cd in mNSCs. More interestingly, the supplementation of lysophosphatidylethanolamine (LPE) attenuated Cd-induced mitochondrial impairment and the inhibition of cell proliferation and differentiation in mNSCs, further supporting our analysis. Overall, the study provides new insights into the mechanisms of Cd-induced neurotoxicity.
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Affiliation(s)
- Yixi Li
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jiming Zhang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yuwei Zhang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Bing Zhang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zheng Wang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Chunhua Wu
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zhijun Zhou
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xiuli Chang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China.
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3
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Liu N, Huang L, Xu H, He X, He X, Cao J, Xu W, Wang Y, Wei H, Wang S, Zheng H, Gao S, Xu Y, Lu W. Phosphatidylserine decarboxylase downregulation in uric acid‑induced hepatic mitochondrial dysfunction and apoptosis. MedComm (Beijing) 2023; 4:e336. [PMID: 37502610 PMCID: PMC10369160 DOI: 10.1002/mco2.336] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 06/24/2023] [Accepted: 06/26/2023] [Indexed: 07/29/2023] Open
Abstract
The molecular mechanisms underlying uric acid (UA)-induced mitochondrial dysfunction and apoptosis have not yet been elucidated. Herein, we investigated underlying mechanisms of UA in the development of mitochondrial dysfunction and apoptosis. We analyzed blood samples of individuals with normal UA levels and patients with hyperuricemia. Results showed that patients with hyperuricemia had significantly elevated levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, which may indicate liver or mitochondrial damage in patients with hyperuricemia. Subsequently, lipidomic analysis of mouse liver tissue mitochondria and human liver L02 cell mitochondria was performed. Compared with control group levels, high UA increased mitochondrial phosphatidylserine (PS) and decreased mitochondrial phosphatidylethanolamine (PE) levels, whereas the expression of mitochondrial phosphatidylserine decarboxylase (PISD) that mediates PS and PE conversion was downregulated. High UA levels also inhibited signal transducer and activator of transcription 3 (STAT3) phosphorylation as well as mitochondrial respiration, while inducing apoptosis both in vivo and in vitro. Treatment with allopurinol, overexpression of PISD, and lyso-PE (LPE) administration significantly attenuated the three above-described effects in vitro. In conclusion, UA may induce mitochondrial dysfunction and apoptosis through mitochondrial PISD downregulation. This study provides a new perspective on liver damage caused by hyperuricemia.
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Affiliation(s)
- Ning Liu
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
- Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Growth Regulation and Transformation Research of Zhejiang Province, School of Life SciencesWestlake UniversityHangzhouZhejiangChina
- College of Life SciencesZhejiang UniversityHangzhouZhejiangChina
- Institute of BiologyWestlake Institute for Advanced StudyHangzhouZhejiang ProvinceChina
| | - Lei Huang
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Hu Xu
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Xinyu He
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Xueqing He
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Jun Cao
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Wenjun Xu
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Yaoxing Wang
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Hongquan Wei
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Sheng Wang
- Center for Scientific ResearchAnhui Medical UniversityHefeiAnhuiChina
| | - Hong Zheng
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Shan Gao
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Youzhi Xu
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
| | - Wenjie Lu
- Basic Medical CollegeAnhui Medical UniversityHefeiAnhuiChina
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4
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Choi JY, Lopes L, Ben Mamoun C, Voelker DR. Maturation of the malarial phosphatidylserine decarboxylase is mediated by high affinity binding to anionic phospholipids. J Biol Chem 2023; 299:104659. [PMID: 36997087 PMCID: PMC10172927 DOI: 10.1016/j.jbc.2023.104659] [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: 01/17/2023] [Revised: 03/18/2023] [Accepted: 03/23/2023] [Indexed: 03/31/2023] Open
Abstract
Decarboxylation of phosphatidylserine (PS) to form phosphatidylethanolamine by PS decarboxylases (PSDs) is an essential process in most eukaryotes. Processing of a malarial PSD proenzyme into its active alpha and beta subunits is by an autoendoproteolytic mechanism regulated by anionic phospholipids, with PS serving as an activator and phosphatidylglycerol (PG), phosphatidylinositol, and phosphatidic acid acting as inhibitors. The biophysical mechanism underlying this regulation remains unknown. We used solid phase lipid binding, liposome-binding assays, and surface plasmon resonance to examine the binding specificity of a processing-deficient Plasmodium PSD (PkPSDS308A) mutant enzyme and demonstrated that the PSD proenzyme binds strongly to PS and PG but not to phosphatidylethanolamine and phosphatidylcholine. The equilibrium dissociation constants (Kd) of PkPSD with PS and PG were 80.4 nM and 66.4 nM, respectively. The interaction of PSD with PS is inhibited by calcium, suggesting that the binding mechanism involves ionic interactions. In vitro processing of WT PkPSD proenzyme was also inhibited by calcium, consistent with the conclusion that PS binding to PkPSD through ionic interactions is required for the proenzyme processing. Peptide mapping identified polybasic amino acid motifs in the proenzyme responsible for binding to PS. Altogether, the data demonstrate that malarial PSD maturation is regulated through a strong physical association between PkPSD proenzyme and anionic lipids. Inhibition of the specific interaction between the proenzyme and the lipids can provide a novel mechanism to disrupt PSD enzyme activity, which has been suggested as a target for antimicrobials, and anticancer therapies.
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Affiliation(s)
- Jae-Yeon Choi
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA; Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, Connecticut, USA
| | - Lauren Lopes
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA
| | - Choukri Ben Mamoun
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, Connecticut, USA
| | - Dennis R Voelker
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA.
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5
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Kwarteng DO, Gangoda M, Kooijman EE. The effect of methylated phosphatidylethanolamine derivatives on the ionization properties of signaling phosphatidic acid. Biophys Chem 2023; 296:107005. [PMID: 36934676 DOI: 10.1016/j.bpc.2023.107005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/07/2023] [Indexed: 03/16/2023]
Abstract
Phosphatidylethanolamine (PE) and Phosphatidylcholine (PC) are the most abundant glycerophospholipids in eukaryotic membranes. The differences in the physicochemical properties of their headgroups have contrasting modulatory effects on their interaction with intracellular macromolecules. As such, their overall impact on membrane structure and function differs significantly. Enzymatic methylation of PE's amine headgroup produces two methylated derivatives namely monomethyl PE (MMPE) and dimethyl PE (DMPE) which have physicochemical properties that generally range between that of PE and PC. Additionally, their influence on membrane properties differs from both PE and PC. Although variations in headgroup methylation have been reported to affect signaling pathways, the direct influence that these differences exert on the ionization properties of signaling phospholipids have not been investigated. Here, we briefly review membrane function and structure that are mediated by the differences in headgroup methylation between PE, MMPE, DMPE and PC. In addition, using 31P MAS NMR, we investigate the effect of these four phospholipids on the ionization properties of the ubiquitous signaling anionic lipid phosphatidic acid (PA). Our results show that PA's ionization properties are differentially affected by changes in phospholipid headgroup methylation. This could have important implications for PA-protein binding and hence physiological functions in cells where signaling events lead to changes in abundance of methylated PE derivatives in the membrane.
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Affiliation(s)
- Desmond Owusu Kwarteng
- Department of Biological Sciences, Kent State University, P.O. Box 5190, Kent, OH 44242, USA.
| | - Mahinda Gangoda
- Department of Chemistry & Biochemistry, Kent State University, P.O. Box 5190, Kent, OH 44242, USA
| | - Edgar E Kooijman
- Department of Biological Sciences, Kent State University, P.O. Box 5190, Kent, OH 44242, USA.
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6
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St Germain M, Iraji R, Bakovic M. Phosphatidylethanolamine homeostasis under conditions of impaired CDP-ethanolamine pathway or phosphatidylserine decarboxylation. Front Nutr 2023; 9:1094273. [PMID: 36687696 PMCID: PMC9849821 DOI: 10.3389/fnut.2022.1094273] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/14/2022] [Indexed: 01/07/2023] Open
Abstract
Phosphatidylethanolamine is the major inner-membrane lipid in the plasma and mitochondrial membranes. It is synthesized in the endoplasmic reticulum from ethanolamine and diacylglycerol (DAG) by the CDP-ethanolamine pathway and from phosphatidylserine by decarboxylation in the mitochondria. Recently, multiple genetic disorders that impact these pathways have been identified, including hereditary spastic paraplegia 81 and 82, Liberfarb syndrome, and a new type of childhood-onset neurodegeneration-CONATOC. Individuals with these diseases suffer from multisystem disorders mainly affecting neuronal function. This indicates the importance of maintaining proper phospholipid homeostasis when major biosynthetic pathways are impaired. This study summarizes the current knowledge of phosphatidylethanolamine metabolism in order to identify areas of future research that might lead to the development of treatment options.
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7
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Stanchev LD, Rizzo J, Peschel R, Pazurek LA, Bredegaard L, Veit S, Laerbusch S, Rodrigues ML, López-Marqués RL, Günther Pomorski T. P-Type ATPase Apt1 of the Fungal Pathogen Cryptococcus neoformans Is a Lipid Flippase of Broad Substrate Specificity. J Fungi (Basel) 2021; 7:jof7100843. [PMID: 34682264 PMCID: PMC8537059 DOI: 10.3390/jof7100843] [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: 07/30/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 11/16/2022] Open
Abstract
Lipid flippases of the P4-ATPase family are ATP-driven transporters that translocate lipids from the exoplasmic to the cytosolic leaflet of biological membranes. In the encapsulated fungal pathogen Cryptococcus neoformans, the P4-ATPase Apt1p is an important regulator of polysaccharide secretion and pathogenesis, but its biochemical characterization is lacking. Phylogenetic analysis revealed that Apt1p belongs to the subclade of P4A-ATPases characterized by the common requirement for a β-subunit. Using heterologous expression in S. cerevisiae, we demonstrate that Apt1p forms a heterodimeric complex with the C. neoformans Cdc50 protein. This association is required for both localization and activity of the transporter complex. Lipid flippase activity of the heterodimeric complex was assessed by complementation tests and uptake assays employing fluorescent lipids and revealed a broad substrate specificity, including several phospholipids, the alkylphospholipid miltefosine, and the glycolipids glucosyl- and galactosylceramide. Our results suggest that transbilayer lipid transport in C. neoformans is finely regulated to promote fungal virulence, which reinforces the potential of Apt1p as a target for antifungal drug development.
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Affiliation(s)
- Lyubomir Dimitrov Stanchev
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.D.S.); (R.P.); (L.A.P.); (S.V.); (S.L.)
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark; (L.B.); (R.L.L.-M.)
| | - Juliana Rizzo
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (J.R.); (M.L.R.)
- Unité Biologie des ARN des Pathogènes Fongiques, Département de Mycologie, Institut Pasteur, 75015 Paris, France
| | - Rebecca Peschel
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.D.S.); (R.P.); (L.A.P.); (S.V.); (S.L.)
| | - Lilli A. Pazurek
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.D.S.); (R.P.); (L.A.P.); (S.V.); (S.L.)
| | - Lasse Bredegaard
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark; (L.B.); (R.L.L.-M.)
| | - Sarina Veit
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.D.S.); (R.P.); (L.A.P.); (S.V.); (S.L.)
| | - Sabine Laerbusch
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.D.S.); (R.P.); (L.A.P.); (S.V.); (S.L.)
| | - Marcio L. Rodrigues
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (J.R.); (M.L.R.)
- Instituto Carlos Chagas, Fiocruz, Curitiba 81310-020, Brazil
| | - Rosa L. López-Marqués
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark; (L.B.); (R.L.L.-M.)
| | - Thomas Günther Pomorski
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.D.S.); (R.P.); (L.A.P.); (S.V.); (S.L.)
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark; (L.B.); (R.L.L.-M.)
- Correspondence: ; Tel.: +49-234-32-24430
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8
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Ristovski M, Farhat D, Bancud SEM, Lee JY. Lipid Transporters Beam Signals from Cell Membranes. MEMBRANES 2021; 11:562. [PMID: 34436325 PMCID: PMC8399137 DOI: 10.3390/membranes11080562] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 12/12/2022]
Abstract
Lipid composition in cellular membranes plays an important role in maintaining the structural integrity of cells and in regulating cellular signaling that controls functions of both membrane-anchored and cytoplasmic proteins. ATP-dependent ABC and P4-ATPase lipid transporters, two integral membrane proteins, are known to contribute to lipid translocation across the lipid bilayers on the cellular membranes. In this review, we will highlight current knowledge about the role of cholesterol and phospholipids of cellular membranes in regulating cell signaling and how lipid transporters participate this process.
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Affiliation(s)
- Miliça Ristovski
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (M.R.); (D.F.); (S.E.M.B.)
- Translational and Molecular Medicine Program, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Danny Farhat
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (M.R.); (D.F.); (S.E.M.B.)
- Biomedical Sciences Program, Faculty of Science, University of Ottawa, Ottawa, ON K1H 6N5, Canada
| | - Shelly Ellaine M. Bancud
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (M.R.); (D.F.); (S.E.M.B.)
- Translational and Molecular Medicine Program, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jyh-Yeuan Lee
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (M.R.); (D.F.); (S.E.M.B.)
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9
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Sam PN, Calzada E, Acoba MG, Zhao T, Watanabe Y, Nejatfard A, Trinidad JC, Shutt TE, Neal SE, Claypool SM. Impaired phosphatidylethanolamine metabolism activates a reversible stress response that detects and resolves mutant mitochondrial precursors. iScience 2021; 24:102196. [PMID: 33718843 PMCID: PMC7921845 DOI: 10.1016/j.isci.2021.102196] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/27/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023] Open
Abstract
Phosphatidylethanolamine (PE) made in mitochondria has long been recognized as an important precursor for phosphatidylcholine production that occurs in the endoplasmic reticulum (ER). Recently, the strict mitochondrial localization of the enzyme that makes PE in the mitochondrion, phosphatidylserine decarboxylase 1 (Psd1), was questioned. Since a dual localization of Psd1 to the ER would have far-reaching implications, we initiated our study to independently re-assess the subcellular distribution of Psd1. Our results support the unavoidable conclusion that the vast majority, if not all, of functional Psd1 resides in the mitochondrion. Through our efforts, we discovered that mutant forms of Psd1 that impair a self-processing step needed for it to become functional are dually localized to the ER when expressed in a PE-limiting environment. We conclude that severely impaired cellular PE metabolism provokes an ER-assisted adaptive response that is capable of identifying and resolving nonfunctional mitochondrial precursors.
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Affiliation(s)
- Pingdewinde N. Sam
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michelle Grace Acoba
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Tian Zhao
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Yasunori Watanabe
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Anahita Nejatfard
- Division of Biological Sciences, The Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | | | - Timothy E. Shutt
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Sonya E. Neal
- Division of Biological Sciences, The Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Steven M. Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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10
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The transport mechanism of P4 ATPase lipid flippases. Biochem J 2021; 477:3769-3790. [PMID: 33045059 DOI: 10.1042/bcj20200249] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/02/2020] [Accepted: 09/16/2020] [Indexed: 12/18/2022]
Abstract
P4 ATPase lipid flippases are ATP-driven transporters that translocate specific lipids from the exoplasmic to the cytosolic leaflet of biological membranes, thus establishing a lipid gradient between the two leaflets that is essential for many cellular processes. While substrate specificity, subcellular and tissue-specific expression, and physiological functions have been assigned to a number of these transporters in several organisms, the mechanism of lipid transport has been a topic of intense debate in the field. The recent publication of a series of structural models based on X-ray crystallography and cryo-EM studies has provided the first glimpse into how P4 ATPases have adapted the transport mechanism used by the cation-pumping family members to accommodate a substrate that is at least an order of magnitude larger than cations.
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11
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López-Marqués RL. Lipid flippases in polarized growth. Curr Genet 2021; 67:255-262. [PMID: 33388852 DOI: 10.1007/s00294-020-01145-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 12/31/2022]
Abstract
Polarized growth is required in eukaryotic cells for processes such as cell division, morphogenesis and motility, which involve conserved and interconnected signalling pathways controlling cell cycle progression, cytoskeleton reorganization and secretory pathway functioning. While many of the factors involved in polarized growth are known, it is not yet clear how they are coordinated both spatially and temporally. Several lines of evidence point to the important role of lipid flippases in polarized growth events. Lipid flippases, which mainly belong to the P4 subfamily of P-type ATPases, are active transporters that move different lipids to the cytosolic side of biological membranes at the expense of ATP. The involvement of the Saccharomyces cerevisiae plasma membrane P4 ATPases Dnf1p and Dnf2p in polarized growth and their activation by kinase phosphorylation were established some years ago. However, these two proteins do not seem to be responsible for the phosphatidylserine internalization required for early recruitment of proteins to the plasma membrane during yeast mating and budding. In a recent publication, we demonstrated that the Golgi-localized P4 ATPase Dnf3p has a preference for PS as a substrate, can reach the plasma membrane in a cell cycle-dependent manner, and is regulated by the same kinases that activate Dnf1p and Dnf2p. This finding solves a long-lasting enigma in the field of lipid flippases and suggests that tight and heavily coordinated spatiotemporal control of lipid translocation at the plasma membrane is important for proper polarized growth.
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Affiliation(s)
- Rosa Laura López-Marqués
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.
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12
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Chen K, Günay-Esiyok Ö, Klingeberg M, Marquardt S, Pomorski TG, Gupta N. Aminoglycerophospholipid flipping and P4-ATPases in Toxoplasma gondii. J Biol Chem 2021; 296:100315. [PMID: 33485966 PMCID: PMC7949121 DOI: 10.1016/j.jbc.2021.100315] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 12/29/2020] [Accepted: 01/13/2021] [Indexed: 11/30/2022] Open
Abstract
Lipid flipping in the membrane bilayers is a widespread eukaryotic phenomenon that is catalyzed by assorted P4-ATPases. Its occurrence, mechanism, and importance in apicomplexan parasites have remained elusive, however. Here we show that Toxoplasma gondii, an obligate intracellular parasite with high clinical relevance, can salvage phosphatidylserine (PtdSer) and phosphatidylethanolamine (PtdEtn) but not phosphatidylcholine (PtdCho) probes from its milieu. Consistently, the drug analogs of PtdCho are broadly ineffective in the parasite culture. NBD-PtdSer imported to the parasite interior is decarboxylated to NBD-PtdEtn, while the latter is not methylated to yield PtdCho, which confirms the expression of PtdSer decarboxylase but a lack of PtdEtn methyltransferase activity and suggests a role of exogenous lipids in membrane biogenesis of T. gondii. Flow cytometric quantitation of NBD-probes endorsed the selectivity of phospholipid transport and revealed a dependence of the process on energy and protein. Accordingly, our further work identified five P4-ATPases (TgP4-ATPase1-5), all of which harbor the signature residues and motifs required for phospholipid flipping. Of the four proteins expressed during the lytic cycle, TgP4-ATPase1 is present in the apical plasmalemma; TgP4-ATPase3 resides in the Golgi network along with its noncatalytic partner Ligand Effector Module 3 (TgLem3), whereas TgP4-ATPase2 and TgP4-ATPase5 localize in the plasmalemma as well as endo/cytomembranes. Last but not least, auxin-induced degradation of TgP4-ATPase1-3 impaired the parasite growth in human host cells, disclosing their crucial roles during acute infection. In conclusion, we show selective translocation of PtdEtn and PtdSer at the parasite surface and provide the underlying mechanistic and physiological insights in a model eukaryotic pathogen.
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Affiliation(s)
- Kai Chen
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Özlem Günay-Esiyok
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Melissa Klingeberg
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Stephan Marquardt
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany; Department of Experimental Biophysics, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Thomas Günther Pomorski
- Department of Experimental Biophysics, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany; Department of Biological Sciences, Birla Institute of Technology and Science Pilani (BITS-P), Hyderabad, India.
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13
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Shiino H, Furuta S, Kojima R, Kimura K, Endo T, Tamura Y. Phosphatidylserine flux into mitochondria unveiled by organelle-targeted Escherichia coli phosphatidylserine synthase PssA. FEBS J 2020; 288:3285-3299. [PMID: 33283454 DOI: 10.1111/febs.15657] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 11/12/2020] [Accepted: 12/04/2020] [Indexed: 11/26/2022]
Abstract
Most phospholipids are synthesised in the endoplasmic reticulum and distributed to other cellular membranes. Although the vesicle transport contributes to the phospholipid distribution among the endomembrane system, exactly how phospholipids are transported to, from and between mitochondrial membranes remains unclear. To gain insights into phospholipid transport routes into mitochondria, we expressed the Escherichia coli phosphatidylserine (PS) synthase PssA in various membrane compartments with distinct membrane topologies in yeast cells lacking a sole PS synthase (Cho1). Interestingly, PssA could complement loss of Cho1 when targeted to the endoplasmic reticulum (ER), peroxisome, or lipid droplet membranes. Synthesised PS could be converted to phosphatidylethanolamine (PE) by Psd1, the mitochondrial PS decarboxylase, suggesting that phospholipids synthesised in the peroxisomes and low doses (LDs) can efficiently reach mitochondria. Furthermore, we found that PssA which has been integrated into the mitochondrial inner membrane (MIM) from the matrix side could partially complement the loss of Cho1. The PS synthesised in the MIM was also converted to PE, indicating that PS flops across the MIM to become PE. These findings expand our understanding of the intracellular phospholipid transport routes via mitochondria.
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Affiliation(s)
| | | | | | | | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Japan
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14
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Frøsig MM, Costa SR, Liesche J, Østerberg JT, Hanisch S, Nintemann S, Sørensen H, Palmgren M, Pomorski TG, López-Marqués RL. Pseudohyphal growth in Saccharomyces cerevisiae involves protein kinase-regulated lipid flippases. J Cell Sci 2020; 133:jcs235994. [PMID: 32661085 DOI: 10.1242/jcs.235994] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 07/01/2020] [Indexed: 12/15/2022] Open
Abstract
Lipid flippases of the P4 ATPase family establish phospholipid asymmetry in eukaryotic cell membranes and are involved in many essential cellular processes. The yeast Saccharomyces cerevisiae contains five P4 ATPases, among which Dnf3p is poorly characterized. Here, we demonstrate that Dnf3p is a flippase that catalyzes translocation of major glycerophospholipids, including phosphatidylserine, towards the cytosolic membrane leaflet. Deletion of the genes encoding Dnf3p and the distantly related P4 ATPases Dnf1p and Dnf2p results in yeast mutants with aberrant formation of pseudohyphae, suggesting that the Dnf1p-Dnf3p proteins have partly redundant functions in the control of this specialized form of polarized growth. Furthermore, as previously demonstrated for Dnf1 and Dnf2p, the phospholipid flipping activity of Dnf3p is positively regulated by flippase kinase 1 (Fpk1p) and Fpk2p. Phylogenetic analyses demonstrate that Dnf3p belongs to a subfamily of P4 ATPases specific for fungi and are likely to represent a hallmark of fungal evolution.
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Affiliation(s)
- Merethe Mørch Frøsig
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Sara Rute Costa
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Johannes Liesche
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Jeppe Thulin Østerberg
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Susanne Hanisch
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Sebastian Nintemann
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Helle Sørensen
- Data Science Lab, Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Michael Palmgren
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Thomas Günther Pomorski
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Rosa L López-Marqués
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
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15
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Choi JY, Black R, Lee H, Di Giovanni J, Murphy RC, Ben Mamoun C, Voelker DR. An improved and highly selective fluorescence assay for measuring phosphatidylserine decarboxylase activity. J Biol Chem 2020; 295:9211-9222. [PMID: 32430397 PMCID: PMC7335775 DOI: 10.1074/jbc.ra120.013421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/14/2020] [Indexed: 11/06/2022] Open
Abstract
Phosphatidylserine decarboxylases (PSDs) catalyze the conversion of phosphatidylserine (PS) to phosphatidylethanolamine (PE), a critical step in membrane biogenesis and a potential target for development of antimicrobial and anti-cancer drugs. PSD activity has typically been quantified using radioactive substrates and products. Recently, we described a fluorescence-based assay that measures the PSD reaction using distyrylbenzene-bis-aldehyde (DSB-3), whose reaction with PE produces a fluorescence signal. However, DSB-3 is not widely available and also reacts with PSD's substrate, PS, producing an adduct with lower fluorescence yield than that of PE. Here, we report a new fluorescence-based assay that is specific for PSD and in which the presence of PS causes only negligible background. This new assay uses 1,2-diacetyl benzene/β-mercaptoethanol, which forms a fluorescent iso-indole-mercaptide conjugate with PE. PE detection with this method is very sensitive and comparable with detection by radiochemical methods. Model reactions examining adduct formation with ethanolamine produced stable products of exact masses (m/z) of 342.119 and 264.105. The assay is robust, with a signal/background ratio of 24, and can readily detect formation of 100 pmol of PE produced from Escherichia coli membranes, Candida albicans mitochondria, or HeLa cell mitochondria. PSD activity can easily be quantified by sequential reagent additions in 96- or 384-well plates, making it readily adaptable to high-throughput screening for PSD inhibitors. This new assay now enables straightforward large-scale screening for PSD inhibitors against pathogenic fungi, antibiotic-resistant bacteria, and neoplastic mammalian cells.
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Affiliation(s)
- Jae-Yeon Choi
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA
| | - Raymond Black
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA
| | - HeeJung Lee
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA
| | - James Di Giovanni
- Department of Pharmacology, University of Colorado Denver, Aurora, Colorado, USA
| | - Robert C Murphy
- Department of Pharmacology, University of Colorado Denver, Aurora, Colorado, USA
| | - Choukri Ben Mamoun
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Dennis R Voelker
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA.
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16
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Watanabe Y, Watanabe Y, Watanabe S. Structural Basis for Phosphatidylethanolamine Biosynthesis by Bacterial Phosphatidylserine Decarboxylase. Structure 2020; 28:799-809.e5. [PMID: 32402247 DOI: 10.1016/j.str.2020.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 03/12/2020] [Accepted: 04/08/2020] [Indexed: 02/06/2023]
Abstract
In both prokaryotes and eukaryotes, phosphatidylethanolamine (PE), one of the most abundant membrane phospholipids, plays important roles in various membrane functions and is synthesized through the decarboxylation of phosphatidylserine (PS) by PS decarboxylases (PSDs). However, the catalysis and substrate recognition mechanisms of PSDs remain unclear. In this study, we focused on the PSD from Escherichia coli (EcPsd) and determined the crystal structures of EcPsd in the apo form and PE-bound form at resolutions of 2.6 and 3.6 Å, respectively. EcPsd forms a homodimer, and each protomer has a positively charged substrate binding pocket at the active site. Structure-based mutational analyses revealed that conserved residues in the pocket are involved in PS decarboxylation. EcPsd has an N-terminal hydrophobic helical region that is important for membrane binding, thereby achieving efficient PS recognition. These results provide a structural basis for understanding the mechanism of PE biosynthesis by PSDs.
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Affiliation(s)
- Yasunori Watanabe
- Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.
| | - Yasuo Watanabe
- Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Seiya Watanabe
- Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
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17
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Conserved mechanism of phospholipid substrate recognition by the P4-ATPase Neo1 from Saccharomyces cerevisiae. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158581. [PMID: 31786280 DOI: 10.1016/j.bbalip.2019.158581] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/17/2022]
Abstract
The type IV P-type ATPases (P4-ATPases) thus far characterized are lipid flippases that transport specific substrates, such as phosphatidylserine (PS) and phosphatidylethanolamine (PE), from the exofacial leaflet to the cytofacial leaflet of membranes. This transport activity generates compositional asymmetry between the two leaflets important for signal transduction, cytokinesis, vesicular transport, and host-pathogen interactions. Most P4-ATPases function as a heterodimer with a β-subunit from the Cdc50 protein family, but Neo1 from Saccharomyces cerevisiae and its metazoan orthologs lack a β-subunit requirement and it is unclear how these proteins transport substrate. Here we tested if residues linked to lipid substrate recognition in other P4-ATPases also contribute to Neo1 function in budding yeast. Point mutations altering entry gate residues in the first (Q209A) and fourth (S457Q) transmembrane segments of Neo1, where phospholipid substrate would initially be selected, disrupt PS and PE membrane asymmetry, but do not perturb growth of cells. Mutation of both entry gate residues inactivates Neo1, and cells expressing this variant are inviable. We also identified a gain-of-function mutation in the second transmembrane segment of Neo1 (Neo1[Y222S]), predicted to help form the entry gate, that substantially enhances Neo1's ability to replace the function of a well characterized phospholipid flippase, Drs2, in establishing PS and PE asymmetry. These results suggest a common mechanism for substrate recognition in widely divergent P4-ATPases.
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18
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Rizzo J, Stanchev LD, da Silva VK, Nimrichter L, Pomorski TG, Rodrigues ML. Role of lipid transporters in fungal physiology and pathogenicity. Comput Struct Biotechnol J 2019; 17:1278-1289. [PMID: 31921394 PMCID: PMC6944739 DOI: 10.1016/j.csbj.2019.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/20/2019] [Accepted: 09/02/2019] [Indexed: 02/08/2023] Open
Abstract
The fungal cell wall and membrane are the most common targets of antifungal agents, but the potential of membrane lipid organization in regulating drug-target interactions has yet to be investigated. Energy-dependent lipid transporters have been recently associated with virulence and drug resistance in many pathogenic fungi. To illustrate this view, we discuss (i) the structural and biological aspects of ATP-driven lipid transporters, comprising P-type ATPases and ATP-binding cassette transporters, (ii) the role of these transporters in fungal physiology and virulence, and (iii) the potential of lipid transporters as targets for the development of novel antifungals. These recent observations indicate that the lipid-trafficking machinery in fungi is a promising target for studies on physiology, pathogenesis and drug development.
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Affiliation(s)
- Juliana Rizzo
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Lyubomir Dimitrov Stanchev
- Department of Molecular Biochemistry, Ruhr University Bochum, Faculty of Chemistry and Biochemistry, 44780 Bochum, Germany
- Department of Plant Biology and Biotechnology, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C,Denmark
| | - Vanessa K.A. da Silva
- Programa de Pós-Graduação em Biologia Parasitária do Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil
| | - Leonardo Nimrichter
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Thomas Günther Pomorski
- Department of Molecular Biochemistry, Ruhr University Bochum, Faculty of Chemistry and Biochemistry, 44780 Bochum, Germany
- Department of Plant Biology and Biotechnology, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C,Denmark
| | - Marcio L. Rodrigues
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
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19
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Hendricson A, Umlauf S, Choi JY, Thekkiniath J, Surovtseva YV, Fuller KK, Reynolds TB, Voelker DR, Ben Mamoun C. High-throughput screening for phosphatidylserine decarboxylase inhibitors using a distyrylbenzene-bis-aldehyde (DSB-3)-based fluorescence assay. J Biol Chem 2019; 294:12146-12156. [PMID: 31227523 DOI: 10.1074/jbc.ra119.007766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 06/18/2019] [Indexed: 11/06/2022] Open
Abstract
Phosphatidylserine decarboxylases (PSDs) catalyze the decarboxylation of phosphatidylserine to generate phosphatidylethanolamine, a critical step in phospholipid metabolism in both prokaryotes and eukaryotes. Most PSDs are membrane-bound, and classical radioisotope-based assays for determining their activity in vitro are not suitable for high-throughput drug screening. The finding that the PkPSD from Plasmodium knowlesi can be purified in a soluble and active form and the recent development of a fluorescence-based distyrylbenzene-bis-aldehyde (DSB-3) assay to measure PSD activity in vitro have laid the groundwork for screening chemical libraries for PSD inhibitors. Using this assay, here we conducted a high-throughput screen of a structurally diverse 130,858-compound library against PkPSD. Further characterization of the hits identified in this screening yielded five PkPSD inhibitors with IC50 values ranging from 3.1 to 42.3 μm Lead compounds were evaluated against the pathogenic yeast Candida albicans in the absence or presence of exogenous ethanolamine, and YU253467 and YU254403 were identified as inhibiting both native C. albicans PSD mitochondrial activity and C. albicans growth, with an MIC50 of 22.5 and 15 μg/ml without ethanolamine and an MIC50 of 75 and 60 μg/ml with ethanolamine, respectively. Together, these results provide the first proof of principle for the application of DSB-3-based fluorescent readouts in high-throughput screening for PSD inhibitors. The data set the stage for future analyses to identify more selective and potent PSD inhibitors with antimicrobial or antitumor activities.
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Affiliation(s)
- Adam Hendricson
- Yale Center for Molecular Discovery, West Haven, Connecticut 06516
| | - Sheila Umlauf
- Yale Center for Molecular Discovery, West Haven, Connecticut 06516
| | - Jae-Yeon Choi
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado 80206
| | - Jose Thekkiniath
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, Connecticut 06520
| | | | - Kevin K Fuller
- Departments of Ophthalmology and Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Todd B Reynolds
- Department of Microbiology, College of Arts and Sciences, University of Tennessee, Knoxville, Tennessee 37996
| | - Dennis R Voelker
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado 80206
| | - Choukri Ben Mamoun
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, Connecticut 06520.
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20
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Calzada E, Avery E, Sam PN, Modak A, Wang C, McCaffery JM, Han X, Alder NN, Claypool SM. Phosphatidylethanolamine made in the inner mitochondrial membrane is essential for yeast cytochrome bc 1 complex function. Nat Commun 2019; 10:1432. [PMID: 30926815 PMCID: PMC6441012 DOI: 10.1038/s41467-019-09425-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 03/11/2019] [Indexed: 12/18/2022] Open
Abstract
Of the four separate PE biosynthetic pathways in eukaryotes, one occurs in the mitochondrial inner membrane (IM) and is executed by phosphatidylserine decarboxylase (Psd1). Deletion of Psd1 is lethal in mice and compromises mitochondrial function. We hypothesize that this reflects inefficient import of non-mitochondrial PE into the IM. Here, we test this by re-wiring PE metabolism in yeast by re-directing Psd1 to the outer mitochondrial membrane or the endomembrane system and show that PE can cross the IMS in both directions. Nonetheless, PE synthesis in the IM is critical for cytochrome bc1 complex (III) function and mutations predicted to disrupt a conserved PE-binding site in the complex III subunit, Qcr7, impair complex III activity similar to PSD1 deletion. Collectively, these data challenge the current dogma of PE trafficking and demonstrate that PE made in the IM by Psd1 support the intrinsic functionality of complex III.
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Affiliation(s)
- Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Erica Avery
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Pingdewinde N Sam
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Arnab Modak
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Chunyan Wang
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - J Michael McCaffery
- Integrated Imaging Center, Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Nathan N Alder
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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21
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Zhao T, Goedhart CM, Sam PN, Sabouny R, Lingrell S, Cornish AJ, Lamont RE, Bernier FP, Sinasac D, Parboosingh JS, Vance JE, Claypool SM, Innes AM, Shutt TE. PISD is a mitochondrial disease gene causing skeletal dysplasia, cataracts, and white matter changes. Life Sci Alliance 2019; 2:2/2/e201900353. [PMID: 30858161 PMCID: PMC6412922 DOI: 10.26508/lsa.201900353] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 12/18/2022] Open
Abstract
This work demonstrates that pathogenic variants in PISD cause mitochondrial disease and suggests a novel mechanistic link whereby impaired lipid content in the inner mitochondrial membrane alters the activity of inner mitochondrial membrane proteases. Exome sequencing of two sisters with congenital cataracts, short stature, and white matter changes identified compound heterozygous variants in the PISD gene, encoding the phosphatidylserine decarboxylase enzyme that converts phosphatidylserine to phosphatidylethanolamine (PE) in the inner mitochondrial membrane (IMM). Decreased conversion of phosphatidylserine to PE in patient fibroblasts is consistent with impaired phosphatidylserine decarboxylase (PISD) enzyme activity. Meanwhile, as evidence for mitochondrial dysfunction, patient fibroblasts exhibited more fragmented mitochondrial networks, enlarged lysosomes, decreased maximal oxygen consumption rates, and increased sensitivity to 2-deoxyglucose. Moreover, treatment with lyso-PE, which can replenish the mitochondrial pool of PE, and genetic complementation restored mitochondrial and lysosome morphology in patient fibroblasts. Functional characterization of the PISD variants demonstrates that the maternal variant causes an alternative splice product. Meanwhile, the paternal variant impairs autocatalytic self-processing of the PISD protein required for its activity. Finally, evidence for impaired activity of mitochondrial IMM proteases suggests an explanation as to why the phenotypes of these PISD patients resemble recently described “mitochondrial chaperonopathies.” Collectively, these findings demonstrate that PISD is a novel mitochondrial disease gene.
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Affiliation(s)
- Tian Zhao
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Caitlin M Goedhart
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Pingdewinde N Sam
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rasha Sabouny
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Susanne Lingrell
- Department of Medicine and Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada
| | - Adam J Cornish
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ryan E Lamont
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Francois P Bernier
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - David Sinasac
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jillian S Parboosingh
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | | | - Jean E Vance
- Department of Medicine and Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - A Micheil Innes
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada .,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Timothy E Shutt
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada .,Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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22
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Lipidomics Studies on Mitochondrial Damage of Saccharomyces cerevisiae Induced by Heavy Ion Beam Radiation. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2018. [DOI: 10.1016/s1872-2040(18)61123-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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23
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Basu Ball W, Baker CD, Neff JK, Apfel GL, Lagerborg KA, Žun G, Petrovič U, Jain M, Gohil VM. Ethanolamine ameliorates mitochondrial dysfunction in cardiolipin-deficient yeast cells. J Biol Chem 2018; 293:10870-10883. [PMID: 29866881 DOI: 10.1074/jbc.ra118.004014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 05/29/2018] [Indexed: 01/24/2023] Open
Abstract
Cardiolipin (CL) is a signature phospholipid of the mitochondria required for the formation of mitochondrial respiratory chain (MRC) supercomplexes. The destabilization of MRC supercomplexes is the proximal cause of the pathology associated with the depletion of CL in patients with Barth syndrome. Thus, promoting supercomplex formation could ameliorate mitochondrial dysfunction associated with CL depletion. However, to date, physiologically relevant small-molecule regulators of supercomplex formation have not been identified. Here, we report that ethanolamine (Etn) supplementation rescues the MRC defects by promoting supercomplex assembly in a yeast model of Barth syndrome. We discovered this novel role of Etn while testing the hypothesis that elevating mitochondrial phosphatidylethanolamine (PE), a phospholipid suggested to overlap in function with CL, could compensate for CL deficiency. We found that the Etn supplementation rescues the respiratory growth of CL-deficient Saccharomyces cerevisiae cells in a dose-dependent manner but independently of its incorporation into PE. The rescue was specifically dependent on Etn but not choline or serine, the other phospholipid precursors. Etn improved mitochondrial function by restoring the expression of MRC proteins and promoting supercomplex assembly in CL-deficient cells. Consistent with this mechanism, overexpression of Cox4, the MRC complex IV subunit, was sufficient to promote supercomplex formation in CL-deficient cells. Taken together, our work identifies a novel role of a ubiquitous metabolite, Etn, in attenuating mitochondrial dysfunction caused by CL deficiency.
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Affiliation(s)
- Writoban Basu Ball
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Charli D Baker
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - John K Neff
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Gabriel L Apfel
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Kim A Lagerborg
- the Departments of Medicine and Pharmacology, University of California, San Diego, La Jolla, California 92093
| | - Gašper Žun
- the Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia.,the Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia, and
| | - Uroš Petrovič
- the Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia.,the Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Mohit Jain
- the Departments of Medicine and Pharmacology, University of California, San Diego, La Jolla, California 92093
| | - Vishal M Gohil
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843,
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24
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Morisada S, Ono Y, Kodaira T, Kishino H, Ninomiya R, Mori N, Watanabe H, Ohta A, Horiuchi H, Fukuda R. The membrane‐bound
O
‐acyltransferase Ale1 transfers an acyl moiety to newly synthesized 2‐alkyl‐
sn
‐glycero‐3‐phosphocholine in yeast. FEBS Lett 2018; 592:1829-1836. [DOI: 10.1002/1873-3468.13103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 05/10/2018] [Accepted: 05/11/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Shiho Morisada
- Department of Biotechnology The University of Tokyo Bunkyo‐ku Japan
| | - Yusuke Ono
- Department of Biotechnology The University of Tokyo Bunkyo‐ku Japan
| | - Teruhisa Kodaira
- Department of Applied Biological Chemistry The University of Tokyo Bunkyo‐ku Japan
| | - Hideyuki Kishino
- Department of Biotechnology The University of Tokyo Bunkyo‐ku Japan
| | - Ryo Ninomiya
- Department of Biotechnology The University of Tokyo Bunkyo‐ku Japan
| | - Naoki Mori
- Department of Applied Biological Chemistry The University of Tokyo Bunkyo‐ku Japan
| | - Hidenori Watanabe
- Department of Applied Biological Chemistry The University of Tokyo Bunkyo‐ku Japan
| | - Akinori Ohta
- Department of Biological Chemistry College of Bioscience and Biotechnology Chubu University Kasugai Japan
| | | | - Ryouichi Fukuda
- Department of Biotechnology The University of Tokyo Bunkyo‐ku Japan
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25
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Vance JE. Historical perspective: phosphatidylserine and phosphatidylethanolamine from the 1800s to the present. J Lipid Res 2018; 59:923-944. [PMID: 29661786 DOI: 10.1194/jlr.r084004] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/12/2018] [Indexed: 12/17/2022] Open
Abstract
This article provides a historical account of the discovery, chemistry, and biochemistry of two ubiquitous phosphoglycerolipids, phosphatidylserine (PS) and phosphatidylethanolamine (PE), including the ether lipids. In addition, the article describes the biosynthetic pathways for these phospholipids and how these pathways were elucidated. Several unique functions of PS and PE in mammalian cells in addition to their ability to define physical properties of membranes are discussed. For example, the translocation of PS from the inner to the outer leaflet of the plasma membrane of cells occurs during apoptosis and during some other specific physiological processes, and this translocation is responsible for profound life-or-death events. Moreover, mitochondrial function is severely impaired when the PE content of mitochondria is reduced below a threshold level. The discovery and implications of the existence of membrane contact sites between the endoplasmic reticulum and mitochondria and their relevance for PS and PE metabolism, as well as for mitochondrial function, are also discussed. Many of the recent advances in these fields are due to the use of isotope labeling for tracing biochemical pathways. In addition, techniques for disruption of specific genes in mice are now widely used and have provided major breakthroughs in understanding the roles and metabolism of PS and PE in vivo.
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Affiliation(s)
- Jean E Vance
- Department of Medicine and Group on the Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta T6G 2S2, Canada.
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26
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Mioka T, Fujimura-Kamada K, Mizugaki N, Kishimoto T, Sano T, Nunome H, Williams DE, Andersen RJ, Tanaka K. Phospholipid flippases and Sfk1p, a novel regulator of phospholipid asymmetry, contribute to low permeability of the plasma membrane. Mol Biol Cell 2018. [PMID: 29540528 PMCID: PMC5935070 DOI: 10.1091/mbc.e17-04-0217] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Phospholipid flippase (type 4 P-type ATPase) plays a major role in the generation of phospholipid asymmetry in eukaryotic cell membranes. Loss of Lem3p-Dnf1/2p flippases leads to the exposure of phosphatidylserine (PS) and phosphatidylethanolamine (PE) on the cell surface in yeast, resulting in sensitivity to PS- or PE-binding peptides. We isolated Sfk1p, a conserved membrane protein in the TMEM150/FRAG1/DRAM family, as a multicopy suppressor of this sensitivity. Overexpression of SFK1 decreased PS/PE exposure in lem3Δ mutant cells. Consistent with this, lem3Δ sfk1Δ double mutant cells exposed more PS/PE than the lem3Δ mutant. Sfk1p was previously implicated in the regulation of the phosphatidylinositol-4 kinase Stt4p, but the effect of Sfk1p on PS/PE exposure in lem3Δ was independent of Stt4p. Surprisingly, Sfk1p did not facilitate phospholipid flipping but instead repressed it, even under ATP-depleted conditions. We propose that Sfk1p negatively regulates transbilayer movement of phospholipids irrespective of directions. In addition, we showed that the permeability of the plasma membrane was dramatically elevated in the lem3Δ sfk1Δ double mutant in comparison with the corresponding single mutants. Interestingly, total ergosterol was decreased in the lem3Δ sfk1Δ mutant. Our results suggest that phospholipid asymmetry is required for the maintenance of low plasma membrane permeability.
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Affiliation(s)
- Tetsuo Mioka
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Kita-ku, Sapporo 060-0815, Japan
| | - Konomi Fujimura-Kamada
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Kita-ku, Sapporo 060-0815, Japan
| | - Nahiro Mizugaki
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Kita-ku, Sapporo 060-0815, Japan
| | - Takuma Kishimoto
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Kita-ku, Sapporo 060-0815, Japan
| | - Takamitsu Sano
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Kita-ku, Sapporo 060-0815, Japan
| | - Hitoshi Nunome
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Kita-ku, Sapporo 060-0815, Japan
| | - David E Williams
- Departments of Chemistry and Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Raymond J Andersen
- Departments of Chemistry and Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Kazuma Tanaka
- Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Life Science, Kita-ku, Sapporo 060-0815, Japan
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27
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Cassilly CD, Reynolds TB. PS, It's Complicated: The Roles of Phosphatidylserine and Phosphatidylethanolamine in the Pathogenesis of Candida albicans and Other Microbial Pathogens. J Fungi (Basel) 2018; 4:jof4010028. [PMID: 29461490 PMCID: PMC5872331 DOI: 10.3390/jof4010028] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/09/2018] [Accepted: 02/13/2018] [Indexed: 12/24/2022] Open
Abstract
The phospholipids phosphatidylserine (PS) and phosphatidylethanolamine (PE) play important roles in the virulence of Candida albicans and loss of PS synthesis or synthesis of PE from PS (PS decarboxylase) severely compromises virulence in C. albicans in a mouse model of systemic candidiasis. This review discusses synthesis of PE and PS in C. albicans and mechanisms by which these lipids impact virulence in this fungus. This is further compared to how PS and PE synthesis impact virulence in other fungi, parasites and bacteria. Furthermore, the impact of PS asymmetry on virulence and extracellular vesicle formation in several microbes is reviewed. Finally, the potential for PS and PE synthases as drug targets in these various kingdoms is also examined.
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Affiliation(s)
- Chelsi D Cassilly
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA.
| | - Todd B Reynolds
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA.
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28
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Dalton LE, Bean BDM, Davey M, Conibear E. Quantitative high-content imaging identifies novel regulators of Neo1 trafficking at endosomes. Mol Biol Cell 2017; 28:1539-1550. [PMID: 28404745 PMCID: PMC5449152 DOI: 10.1091/mbc.e16-11-0772] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/05/2017] [Accepted: 04/06/2017] [Indexed: 12/21/2022] Open
Abstract
P4-ATPases are a family of putative phospholipid flippases that regulate lipid membrane asymmetry, which is important for vesicle formation. Two yeast flippases, Drs2 and Neo1, have nonredundant functions in the recycling of the synaptobrevin-like v-SNARE Snc1 from early endosomes. Drs2 activity is needed to form vesicles and regulate its own trafficking, suggesting that flippase activity and localization are linked. However, the role of Neo1 in endosomal recycling is not well characterized. To identify novel regulators of Neo1 trafficking and activity at endosomes, we first identified mutants with impaired recycling of a Snc1-based reporter and subsequently used high-content microscopy to classify these mutants based on the localization of Neo1 or its binding partners, Mon2 and Dop1. This analysis identified a role for Arl1 in stabilizing the Mon2/Dop1 complex and uncovered a new function for Vps13 in early endosome recycling and Neo1 localization. We further showed that the cargo-selective sorting nexin Snx3 is required for Neo1 trafficking and identified an Snx3 sorting motif in the Neo1 N-terminus. Of importance, the Snx3-dependent sorting of Neo1 was required for the correct sorting of another Snx3 cargo protein, suggesting that the incorporation of Neo1 into recycling tubules may influence their formation.
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Affiliation(s)
- Lauren E Dalton
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Björn D M Bean
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Michael Davey
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Elizabeth Conibear
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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29
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Keckesova Z, Donaher JL, De Cock J, Freinkman E, Lingrell S, Bachovchin DA, Bierie B, Tischler V, Noske A, Okondo MC, Reinhardt F, Thiru P, Golub TR, Vance JE, Weinberg RA. LACTB is a tumour suppressor that modulates lipid metabolism and cell state. Nature 2017; 543:681-686. [PMID: 28329758 PMCID: PMC6246920 DOI: 10.1038/nature21408] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 01/18/2017] [Indexed: 02/05/2023]
Abstract
Post-mitotic, differentiated cells exhibit a variety of characteristics that contrast with those of actively growing neoplastic cells, such as the expression of cell-cycle inhibitors and differentiation factors. We hypothesized that the gene expression profiles of these differentiated cells could reveal the identities of genes that may function as tumour suppressors. Here we show, using in vitro and in vivo studies in mice and humans, that the mitochondrial protein LACTB potently inhibits the proliferation of breast cancer cells. Its mechanism of action involves alteration of mitochondrial lipid metabolism and differentiation of breast cancer cells. This is achieved, at least in part, through reduction of the levels of mitochondrial phosphatidylserine decarboxylase, which is involved in the synthesis of mitochondrial phosphatidylethanolamine. These observations uncover a novel mitochondrial tumour suppressor and demonstrate a connection between mitochondrial lipid metabolism and the differentiation program of breast cancer cells, thereby revealing a previously undescribed mechanism of tumour suppression.
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Affiliation(s)
- Zuzana Keckesova
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
| | - Joana Liu Donaher
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
| | - Jasmine De Cock
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
| | - Elizaveta Freinkman
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
- Metabolon, Inc., PO Box 110407, Research Triangle Park, North Carolina 27709, USA
| | - Susanne Lingrell
- Department of Medicine and the Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta T6G 2S2, Canada
| | - Daniel A Bachovchin
- Broad Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Brian Bierie
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
| | - Verena Tischler
- Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Aurelia Noske
- Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Marian C Okondo
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Ferenc Reinhardt
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
| | - Prathapan Thiru
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
| | - Todd R Golub
- Broad Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Jean E Vance
- Department of Medicine and the Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta T6G 2S2, Canada
| | - Robert A Weinberg
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- MIT Ludwig Center for Molecular Oncology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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30
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Niu Y, Qian D, Liu B, Ma J, Wan D, Wang X, He W, Xiang Y. ALA6, a P 4-type ATPase, Is Involved in Heat Stress Responses in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2017; 8:1732. [PMID: 29046690 PMCID: PMC5632816 DOI: 10.3389/fpls.2017.01732] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 09/21/2017] [Indexed: 05/19/2023]
Abstract
Maintaining lipid membrane integrity is an essential aspect of plant tolerance to high temperature. P4-type ATPases are responsible for flipping and stabilizing asymmetric phospholipids in membrane systems, though their functions in stress tolerance are not entirely clear. Aminophospholipid ATPase6 (ALA6) is a member of the P4-type ATPase family, which has 12 members in Arabidopsis thaliana. Here, we show that a loss-of-function mutant of ALA6 (ala6) exhibits clear sensitivity to heat stress, including both basal and acquired thermotolerance treatments. Overexpression of ALA6 improves seedling resistance to heat stress, while mutated ALA6 transgenic plants, in which the conserved functional site of the ALA family has a point mutation, are still susceptible to heat stress like ala6 loss-of-function mutant. In addition, ala6 displays higher ion-leakage during heat treatment, suggesting that the lipid flippase activity of ALA6 plays a vital role in heat stress responses. Transcriptome analysis reveals differences in gene expression between ala6 and wild-type plants with or without heat stress. The differentially expressed genes are involved primarily in the physiological processes of stress response, cellular compartment maintenance, macromolecule stability and energy production. Our results suggest that ALA6 is crucial for the stability of membrane when plants suffer from high temperature stress.
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Affiliation(s)
- Yue Niu
- *Correspondence: Yue Niu, Yun Xiang,
| | | | | | | | | | | | | | - Yun Xiang
- *Correspondence: Yue Niu, Yun Xiang,
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31
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Kawałek A, Jagadeesan C, van der Klei IJ. Impaired biosynthesis of the non-bilayer lipids phosphatidylethanolamine or cardiolipin does not affect peroxisome biogenesis and proliferation in Saccharomyces cerevisiae. Biochem Biophys Res Commun 2016; 480:228-233. [DOI: 10.1016/j.bbrc.2016.10.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 10/13/2016] [Indexed: 10/20/2022]
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32
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Abstract
Cellular membranes display a diversity of functions that are conferred by the unique composition and organization of their proteins and lipids. One important aspect of lipid organization is the asymmetric distribution of phospholipids (PLs) across the plasma membrane. The unequal distribution of key PLs between the cytofacial and exofacial leaflets of the bilayer creates physical surface tension that can be used to bend the membrane; and like Ca2+, a chemical gradient that can be used to transduce biochemical signals. PL flippases in the type IV P-type ATPase (P4-ATPase) family are the principle transporters used to set and repair this PL gradient and the asymmetric organization of these membranes are encoded by the substrate specificity of these enzymes. Thus, understanding the mechanisms of P4-ATPase substrate specificity will help reveal their role in membrane organization and cell biology. Further, decoding the structural determinants of substrate specificity provides investigators the opportunity to mutationally tune this specificity to explore the role of particular PL substrates in P4-ATPase cellular functions. This work reviews the role of P4-ATPases in membrane biology, presents our current understanding of P4-ATPase substrate specificity, and discusses how these fundamental aspects of P4-ATPase enzymology may be used to enhance our knowledge of cellular membrane biology.
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Affiliation(s)
- Bartholomew P. Roland
- Vanderbilt University, Department of Biological Sciences, 1161 21st Ave South, Nashville, TN 37235
| | - Todd R. Graham
- Vanderbilt University, Department of Biological Sciences, 1161 21st Ave South, Nashville, TN 37235
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33
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Pomorski TG, Menon AK. Lipid somersaults: Uncovering the mechanisms of protein-mediated lipid flipping. Prog Lipid Res 2016; 64:69-84. [PMID: 27528189 DOI: 10.1016/j.plipres.2016.08.003] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 08/10/2016] [Indexed: 12/22/2022]
Abstract
Membrane lipids diffuse rapidly in the plane of the membrane but their ability to flip spontaneously across a membrane bilayer is hampered by a significant energy barrier. Thus spontaneous flip-flop of polar lipids across membranes is very slow, even though it must occur rapidly to support diverse aspects of cellular life. Here we discuss the mechanisms by which rapid flip-flop occurs, and what role lipid flipping plays in membrane homeostasis and cell growth. We focus on conceptual aspects, highlighting mechanistic insights from biochemical and in silico experiments, and the recent, ground-breaking identification of a number of lipid scramblases.
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Affiliation(s)
- Thomas Günther Pomorski
- Faculty of Chemistry and Biochemistry, Molecular Biochemistry, Ruhr University Bochum, Universitätstrasse 150, D-44780 Bochum, Germany; Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark.
| | - Anant K Menon
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA.
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34
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Schuler MH, Di Bartolomeo F, Mårtensson CU, Daum G, Becker T. Phosphatidylcholine Affects Inner Membrane Protein Translocases of Mitochondria. J Biol Chem 2016; 291:18718-29. [PMID: 27402832 DOI: 10.1074/jbc.m116.722694] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Indexed: 01/31/2023] Open
Abstract
Two protein translocases transport precursor proteins into or across the inner mitochondrial membrane. The presequence translocase (TIM23 complex) sorts precursor proteins with a cleavable presequence either into the matrix or into the inner membrane. The carrier translocase (TIM22 complex) inserts multispanning proteins into the inner membrane. Both protein import pathways depend on the presence of a membrane potential, which is generated by the activity of the respiratory chain. The non-bilayer-forming phospholipids cardiolipin and phosphatidylethanolamine are required for the activity of the respiratory chain and therefore to maintain the membrane potential for protein import. Depletion of cardiolipin further affects the stability of the TIM23 complex. The role of bilayer-forming phospholipids like phosphatidylcholine (PC) in protein transport into the inner membrane and the matrix is unknown. Here, we report that import of presequence-containing precursors and carrier proteins is impaired in PC-deficient mitochondria. Surprisingly, depletion of PC does not affect stability and activity of respiratory supercomplexes, and the membrane potential is maintained. Instead, the dynamic TIM23 complex is destabilized when the PC levels are reduced, whereas the TIM22 complex remains intact. Our analysis further revealed that initial precursor binding to the TIM23 complex is impaired in PC-deficient mitochondria. We conclude that reduced PC levels differentially affect the TIM22 and TIM23 complexes in mitochondrial protein transport.
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Affiliation(s)
- Max-Hinderk Schuler
- From the Institute for Biochemistry and Molecular Biology, Faculty of Medicine
| | - Francesca Di Bartolomeo
- the Institute for Biochemistry, Graz University of Technology, NaWi Graz, A-8010 Graz, Austria
| | - Christoph U Mårtensson
- From the Institute for Biochemistry and Molecular Biology, Faculty of Medicine, Faculty of Biology, and
| | - Günther Daum
- the Institute for Biochemistry, Graz University of Technology, NaWi Graz, A-8010 Graz, Austria
| | - Thomas Becker
- From the Institute for Biochemistry and Molecular Biology, Faculty of Medicine, BIOSS Centre for Biological Signalling Studies, University of Freiburg, D-79104 Freiburg, Germany and
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35
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Takar M, Wu Y, Graham TR. The Essential Neo1 Protein from Budding Yeast Plays a Role in Establishing Aminophospholipid Asymmetry of the Plasma Membrane. J Biol Chem 2016; 291:15727-39. [PMID: 27235400 DOI: 10.1074/jbc.m115.686253] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic organisms typically express multiple type IV P-type ATPases (P4-ATPases), which establish plasma membrane asymmetry by flipping specific phospholipids from the exofacial to the cytosolic leaflet. Saccharomyces cerevisiae, for example, expresses five P4-ATPases, including Neo1, Drs2, Dnf1, Dnf2, and Dnf3. Neo1 is thought to be a phospholipid flippase, although there is currently no experimental evidence that Neo1 catalyzes this activity or helps establish membrane asymmetry. Here, we use temperature-conditional alleles (neo1(ts)) to test whether Neo1 deficiency leads to loss of plasma membrane asymmetry. Wild-type (WT) yeast normally restrict most of the phosphatidylserine (PS) and phosphatidylethanolamine (PE) to the inner cytosolic leaflet of the plasma membrane. However, the neo1-1(ts) and neo1-2(ts) mutants display a loss of PS and PE asymmetry at permissive growth temperatures as measured by hypersensitivity to pore-forming toxins that target PS (papuamide A) or PE (duramycin) exposed in the extracellular leaflet. When shifted to a semi-permissive growth temperature, the neo1-1(ts) mutant became extremely hypersensitive to duramycin, although the sensitivity to papuamide A was unchanged, indicating preferential exposure of PE. This loss of asymmetry occurs despite the presence of other flippases that flip PS and/or PE. Even when overexpressed, Drs2 and Dnf1 were unable to correct the loss of asymmetry caused by neo1(ts) However, modest overexpression of Neo1 weakly suppressed loss of membrane asymmetry caused by drs2Δ with a more significant correction of PE asymmetry than PS. These results indicate that Neo1 plays an important role in establishing PS and PE plasma membrane asymmetry in budding yeast.
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Affiliation(s)
- Mehmet Takar
- From the Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
| | - Yuantai Wu
- From the Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
| | - Todd R Graham
- From the Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
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36
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Baker CD, Basu Ball W, Pryce EN, Gohil VM. Specific requirements of nonbilayer phospholipids in mitochondrial respiratory chain function and formation. Mol Biol Cell 2016; 27:2161-71. [PMID: 27226479 PMCID: PMC4945136 DOI: 10.1091/mbc.e15-12-0865] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 05/19/2016] [Indexed: 01/06/2023] Open
Abstract
Phosphatidylethanolamine (PE) and cardiolipin have specific roles in the activity and assembly of the mitochondrial respiratory chain supercomplexes, respectively, whereas phosphatidylcholine is redundant. Nonmitochondrial PE can be transported into mitochondria, where it can fully substitute for the lack of mitochondrial PE biosynthesis. Mitochondrial membrane phospholipid composition affects mitochondrial function by influencing the assembly of the mitochondrial respiratory chain (MRC) complexes into supercomplexes. For example, the loss of cardiolipin (CL), a signature non–bilayer-forming phospholipid of mitochondria, results in disruption of MRC supercomplexes. However, the functions of the most abundant mitochondrial phospholipids, bilayer-forming phosphatidylcholine (PC) and non–bilayer-forming phosphatidylethanolamine (PE), are not clearly defined. Using yeast mutants of PE and PC biosynthetic pathways, we show a specific requirement for mitochondrial PE in MRC complex III and IV activities but not for their formation, whereas loss of PC does not affect MRC function or formation. Unlike CL, mitochondrial PE or PC is not required for MRC supercomplex formation, emphasizing the specific requirement of CL in supercomplex assembly. Of interest, PE biosynthesized in the endoplasmic reticulum (ER) can functionally substitute for the lack of mitochondrial PE biosynthesis, suggesting the existence of PE transport pathway from ER to mitochondria. To understand the mechanism of PE transport, we disrupted ER–mitochondrial contact sites formed by the ERMES complex and found that, although not essential for PE transport, ERMES facilitates the efficient rescue of mitochondrial PE deficiency. Our work highlights specific roles of non–bilayer-forming phospholipids in MRC function and formation.
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Affiliation(s)
- Charli D Baker
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Writoban Basu Ball
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Erin N Pryce
- Integrated Imaging Center, Department of Biology, Johns Hopkins University, Baltimore, MD 21218
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
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37
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Calzada E, Onguka O, Claypool SM. Phosphatidylethanolamine Metabolism in Health and Disease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 321:29-88. [PMID: 26811286 DOI: 10.1016/bs.ircmb.2015.10.001] [Citation(s) in RCA: 255] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Phosphatidylethanolamine (PE) is the second most abundant glycerophospholipid in eukaryotic cells. The existence of four only partially redundant biochemical pathways that produce PE, highlights the importance of this essential phospholipid. The CDP-ethanolamine and phosphatidylserine decarboxylase pathways occur in different subcellular compartments and are the main sources of PE in cells. Mammalian development fails upon ablation of either pathway. Once made, PE has diverse cellular functions that include serving as a precursor for phosphatidylcholine and a substrate for important posttranslational modifications, influencing membrane topology, and promoting cell and organelle membrane fusion, oxidative phosphorylation, mitochondrial biogenesis, and autophagy. The importance of PE metabolism in mammalian health has recently emerged following its association with Alzheimer's disease, Parkinson's disease, nonalcoholic liver disease, and the virulence of certain pathogenic organisms.
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Affiliation(s)
- Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ouma Onguka
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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38
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Gsell M, Fankl A, Klug L, Mascher G, Schmidt C, Hrastnik C, Zellnig G, Daum G. A Yeast Mutant Deleted of GPH1 Bears Defects in Lipid Metabolism. PLoS One 2015; 10:e0136957. [PMID: 26327557 PMCID: PMC4556709 DOI: 10.1371/journal.pone.0136957] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 08/10/2015] [Indexed: 11/18/2022] Open
Abstract
In a previous study we demonstrated up-regulation of the yeast GPH1 gene under conditions of phosphatidylethanolamine (PE) depletion caused by deletion of the mitochondrial (M) phosphatidylserine decarboxylase 1 (PSD1) (Gsell et al., 2013, PLoS One. 8(10):e77380. doi: 10.1371/journal.pone.0077380). Gph1p has originally been identified as a glycogen phosphorylase catalyzing degradation of glycogen to glucose in the stationary growth phase of the yeast. Here we show that deletion of this gene also causes decreased levels of phosphatidylcholine (PC), triacylglycerols and steryl esters. Depletion of the two non-polar lipids in a Δgph1 strain leads to lack of lipid droplets, and decrease of the PC level results in instability of the plasma membrane. In vivo labeling experiments revealed that formation of PC via both pathways of biosynthesis, the cytidine diphosphate (CDP)-choline and the methylation route, is negatively affected by a Δgph1 mutation, although expression of genes involved is not down regulated. Altogether, Gph1p besides its function as a glycogen mobilizing enzyme appears to play a regulatory role in yeast lipid metabolism.
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Affiliation(s)
- Martina Gsell
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Ariane Fankl
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Lisa Klug
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Gerald Mascher
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Claudia Schmidt
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Claudia Hrastnik
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Günther Zellnig
- Institute of Plant Sciences, Karl Franzens University Graz, NaWi Graz, Austria
| | - Günther Daum
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
- * E-mail:
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39
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Panatala R, Hennrich H, Holthuis JCM. Inner workings and biological impact of phospholipid flippases. J Cell Sci 2015; 128:2021-32. [PMID: 25918123 DOI: 10.1242/jcs.102715] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The plasma membrane, trans-Golgi network and endosomal system of eukaryotic cells are populated with flippases that hydrolyze ATP to help establish asymmetric phospholipid distributions across the bilayer. Upholding phospholipid asymmetry is vital to a host of cellular processes, including membrane homeostasis, vesicle biogenesis, cell signaling, morphogenesis and migration. Consequently, defining the identity of flippases and their biological impact has been the subject of intense investigations. Recent work has revealed a remarkable degree of kinship between flippases and cation pumps. In this Commentary, we review emerging insights into how flippases work, how their activity is controlled according to cellular demands, and how disrupting flippase activity causes system failure of membrane function, culminating in membrane trafficking defects, aberrant signaling and disease.
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Affiliation(s)
- Radhakrishnan Panatala
- Department of Membrane Enzymology, Bijvoet Center and Institute of Biomembranes, Utrecht University, 3584 Utrecht, The Netherlands Molecular Cell Biology Division, University of Osnabrück, 49076 Osnabrück, Germany
| | - Hanka Hennrich
- Department of Membrane Enzymology, Bijvoet Center and Institute of Biomembranes, Utrecht University, 3584 Utrecht, The Netherlands
| | - Joost C M Holthuis
- Department of Membrane Enzymology, Bijvoet Center and Institute of Biomembranes, Utrecht University, 3584 Utrecht, The Netherlands Molecular Cell Biology Division, University of Osnabrück, 49076 Osnabrück, Germany
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40
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Choi JY, Duraisingh MT, Marti M, Ben Mamoun C, Voelker DR. From Protease to Decarboxylase: THE MOLECULAR METAMORPHOSIS OF PHOSPHATIDYLSERINE DECARBOXYLASE. J Biol Chem 2015; 290:10972-80. [PMID: 25724650 DOI: 10.1074/jbc.m115.642413] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Indexed: 12/26/2022] Open
Abstract
Phosphatidylserine decarboxylase (PSDs) play a central role in the synthesis of phosphatidylethanolamine in numerous species of prokaryotes and eukaryotes. PSDs are unusual decarboxylase containing a pyruvoyl prosthetic group within the active site. The covalently attached pyruvoyl moiety is formed in a concerted reaction when the PSD proenzyme undergoes an endoproteolytic cleavage into a large β-subunit, and a smaller α-subunit, which harbors the prosthetic group at its N terminus. The mechanism of PSD proenzyme cleavage has long been unclear. Using a coupled in vitro transcription/translation system with the soluble Plasmodium knowlesi enzyme (PkPSD), we demonstrate that the post-translational processing is inhibited by the serine protease inhibitor, phenylmethylsulfonyl fluoride. Comparison of PSD sequences across multiple phyla reveals a uniquely conserved aspartic acid within an FFXRX6RX12PXD motif, two uniquely conserved histidine residues within a PXXYHXXHXP motif, and a uniquely conserved serine residue within a GS(S/T) motif, suggesting that PSDs belong to the D-H-S serine protease family. The function of the conserved D-H-S residues was probed using site-directed mutagenesis of PkPSD. The results from these mutagenesis experiments reveal that Asp-139, His-198, and Ser-308 are all essential for endoproteolytic processing of PkPSD, which occurs in cis. In addition, within the GS(S/T) motif found in all PSDs, the Gly-307 residue is also essential, but the Ser/Thr-309 is non-essential. These results define the mechanism whereby PSDs begin their biochemical existence as proteases that execute one autoendoproteolytic cleavage reaction to give rise to a mature PSD harboring a pyruvoyl prosthetic group.
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Affiliation(s)
- Jae-Yeon Choi
- From the Department of Medicine, Basic Science Section, National Jewish Health, Denver, Colorado 80206
| | - Manoj T Duraisingh
- the Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts 02115
| | - Matthias Marti
- the Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts 02115
| | - Choukri Ben Mamoun
- the Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, Connecticut 06520, and
| | - Dennis R Voelker
- From the Department of Medicine, Basic Science Section, National Jewish Health, Denver, Colorado 80206,
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41
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P4-ATPases: lipid flippases in cell membranes. Pflugers Arch 2015; 466:1227-40. [PMID: 24077738 PMCID: PMC4062807 DOI: 10.1007/s00424-013-1363-4] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 09/11/2013] [Accepted: 09/11/2013] [Indexed: 12/13/2022]
Abstract
Cellular membranes, notably eukaryotic plasma membranes, are equipped with special proteins that actively translocate lipids from one leaflet to the other and thereby help generate membrane lipid asymmetry. Among these ATP-driven transporters, the P4 subfamily of P-type ATPases (P4-ATPases) comprises lipid flippases that catalyze the translocation of phospholipids from the exoplasmic to the cytosolic leaflet of cell membranes. While initially characterized as aminophospholipid translocases, recent studies of individual P4-ATPase family members from fungi, plants, and animals show that P4-ATPases differ in their substrate specificities and mediate transport of a broader range of lipid substrates, including lysophospholipids and synthetic alkylphospholipids. At the same time, the cellular processes known to be directly or indirectly affected by this class of transporters have expanded to include the regulation of membrane traffic, cytoskeletal dynamics, cell division, lipid metabolism, and lipid signaling. In this review, we will summarize the basic features of P4-ATPases and the physiological implications of their lipid transport activity in the cell.
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42
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Waiczies S, Lepore S, Sydow K, Drechsler S, Ku MC, Martin C, Lorenz D, Schütz I, Reimann HM, Purfürst B, Dieringer MA, Waiczies H, Dathe M, Pohlmann A, Niendorf T. Anchoring dipalmitoyl phosphoethanolamine to nanoparticles boosts cellular uptake and fluorine-19 magnetic resonance signal. Sci Rep 2015; 5:8427. [PMID: 25673047 PMCID: PMC5389132 DOI: 10.1038/srep08427] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 01/15/2015] [Indexed: 01/19/2023] Open
Abstract
Magnetic resonance (MR) methods to detect and quantify fluorine (19F) nuclei provide the opportunity to study the fate of cellular transplants in vivo. Cells are typically labeled with 19F nanoparticles, introduced into living organisms and tracked by 19F MR methods. Background-free imaging and quantification of cell numbers are amongst the strengths of 19F MR-based cell tracking but challenges pertaining to signal sensitivity and cell detection exist. In this study we aimed to overcome these limitations by manipulating the aminophospholipid composition of 19F nanoparticles in order to promote their uptake by dendritic cells (DCs). As critical components of biological membranes, phosphatidylethanolamines (PE) were studied. Both microscopy and MR spectroscopy methods revealed a striking (at least one order of magnitude) increase in cytoplasmic uptake of 19F nanoparticles in DCs following enrichment with 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE). The impact of enriching 19F nanoparticles with PE on DC migration was also investigated. By manipulating the nanoparticle composition and as a result the cellular uptake we provide here one way of boosting 19F signal per cell in order to overcome some of the limitations related to 19F MR signal sensitivity. The boost in signal is ultimately necessary to detect and track cells in vivo.
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Affiliation(s)
- Sonia Waiczies
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Stefano Lepore
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Karl Sydow
- Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Susanne Drechsler
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Min-Chi Ku
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Conrad Martin
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Dorothea Lorenz
- Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Irene Schütz
- Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Henning M Reimann
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Bettina Purfürst
- Electron Microscopy Core Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Matthias A Dieringer
- 1] Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany [2] Experimental and Clinical Research Center, Berlin, Germany
| | | | - Margitta Dathe
- Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine, Berlin, Germany
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43
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Kannan M, Riekhof WR, Voelker DR. Transport of Phosphatidylserine from the Endoplasmic Reticulum to the Site of Phosphatidylserine Decarboxylase2 in Yeast. Traffic 2014; 16:123-34. [DOI: 10.1111/tra.12236] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 10/17/2014] [Accepted: 10/28/2014] [Indexed: 02/03/2023]
Affiliation(s)
- Muthukumar Kannan
- Department of Medicine and Program in Cell Biology; National Jewish Health; Denver CO 80206 USA
| | - Wayne R. Riekhof
- School of Biological Sciences; University of Nebraska; Lincoln NE 68588 USA
| | - Dennis R. Voelker
- Department of Medicine and Program in Cell Biology; National Jewish Health; Denver CO 80206 USA
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44
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Deng L, Kakihara T, Fukuda R, Ohta A. Construction of a Yeast Strain with Regulatable Phospholipid Synthesis for Analysis of the Uptake and Metabolism of Phosphatidylethanolamine with Short Acyl Chains. Biosci Biotechnol Biochem 2014; 71:2313-5. [PMID: 17827694 DOI: 10.1271/bbb.70224] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We constructed a yeast stain, TKY12Ga, in which phosphatidylethanolamine (PE) synthesis can be controlled by means of the carbon source in the medium. When PE synthesis was blocked, its growth was inhibited. However, in the presence of exogenous didecanoyl PE (diC10PE), TKY12Ga grew despite an inability to synthesize PE. Our system, which employs TKY12Ga strain and diC10PE, provides a valuable tool to study the transport and metabolism of PE in yeast.
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Affiliation(s)
- Lan Deng
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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45
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Structure and mechanism of ATP-dependent phospholipid transporters. Biochim Biophys Acta Gen Subj 2014; 1850:461-75. [PMID: 24746984 DOI: 10.1016/j.bbagen.2014.04.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/04/2014] [Accepted: 04/07/2014] [Indexed: 01/09/2023]
Abstract
BACKGROUND ATP-binding cassette (ABC) transporters and P4-ATPases are two large and seemingly unrelated families of primary active pumps involved in moving phospholipids from one leaflet of a biological membrane to the other. SCOPE OF REVIEW This review aims to identify common mechanistic features in the way phospholipid flipping is carried out by two evolutionarily unrelated families of transporters. MAJOR CONCLUSIONS Both protein families hydrolyze ATP, although they employ different mechanisms to use it, and have a comparable size with twelve transmembrane segments in the functional unit. Further, despite differences in overall architecture, both appear to operate by an alternating access mechanism and during transport they might allow access of phospholipids to the internal part of the transmembrane domain. The latter feature is obvious for ABC transporters, but phospholipids and other hydrophobic molecules have also been found embedded in P-type ATPase crystal structures. Taken together, in two diverse groups of pumps, nature appears to have evolved quite similar ways of flipping phospholipids. GENERAL SIGNIFICANCE Our understanding of the structural basis for phospholipid flipping is still limited but it seems plausible that a general mechanism for phospholipid flipping exists in nature. This article is part of a Special Issue entitled Structural biochemistry and biophysics of membrane proteins.
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46
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Martin SA, Gijón MA, Voelker DR, Murphy RC. Measurement of lysophospholipid acyltransferase activities using substrate competition. J Lipid Res 2014; 55:782-91. [PMID: 24563510 DOI: 10.1194/jlr.d044636] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Lysophospholipid acyltransferases (LPATs) incorporate fatty acyl chains into phospholipids via a CoA-dependent mechanism and are important in remodeling phospholipids to generate the molecular species of phospholipids found in cells. These enzymes use one lysophospholipid and one acyl-CoA ester as substrates. Traditional enzyme activity assays engage a single substrate pair, whereas in vivo multiple molecular species exist. We describe here an alternative biochemical assay that provides a mixture of substrates presented to the microsomal extracts. Microsomal preparations from RAW 264.7 cells were used to compare traditional LPAT assays with data obtained using a dual substrate choice assay using six different lysophospholipids and eight different acyl-CoA esters. The complex mixture of newly synthesized phospholipid products was analyzed using LC-MS/MS. Both types of assays provided similar results, but the dual choice assay provided information about multiple fatty acyl chain incorporation into various phospholipid classes in a single reaction. Engineered suppression of LPCAT3 activity in RAW 264.7 cells was easily detected by the dual choice method. These findings demonstrate that this assay is both specific and sensitive and that it provides much richer biochemical detail than traditional assays.
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Affiliation(s)
- Sarah A Martin
- Department of Pharmacology, University of Colorado Denver, Aurora, CO 80045
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47
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Riekhof WR, Wu WI, Jones JL, Nikrad M, Chan MM, Loewen CJR, Voelker DR. An assembly of proteins and lipid domains regulates transport of phosphatidylserine to phosphatidylserine decarboxylase 2 in Saccharomyces cerevisiae. J Biol Chem 2013; 289:5809-19. [PMID: 24366873 DOI: 10.1074/jbc.m113.518217] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Saccharomyces cerevisiae uses multiple biosynthetic pathways for the synthesis of phosphatidylethanolamine. One route involves the synthesis of phosphatidylserine (PtdSer) in the endoplasmic reticulum (ER), the transport of this lipid to endosomes, and decarboxylation by PtdSer decarboxylase 2 (Psd2p) to produce phosphatidylethanolamine. Several proteins and protein motifs are known to be required for PtdSer transport to occur, namely the Sec14p homolog PstB2p/Pdr17p; a PtdIns 4-kinase, Stt4p; and a C2 domain of Psd2p. The focus of this work is on defining the protein-protein and protein-lipid interactions of these components. PstB2p interacts with a protein encoded by the uncharacterized gene YPL272C, which we name Pbi1p (PstB2p-interacting 1). PstB2p, Psd2, and Pbi1p were shown to be lipid-binding proteins specific for phosphatidic acid. Pbi1p also interacts with the ER-localized Scs2p, a binding determinant for several peripheral ER proteins. A complex between Psd2p and PstB2p was also detected, and this interaction was facilitated by a cryptic C2 domain at the extreme N terminus of Psd2p (C2-1) as well the previously characterized C2 domain of Psd2p (C2-2). The predicted N-terminal helical region of PstB2p was necessary and sufficient for promoting the interaction with both Psd2p and Pbi1p. Taken together, these results support a model for PtdSer transport involving the docking of a PtdSer donor membrane with an acceptor via specific protein-protein and protein-lipid interactions. Specifically, our model predicts that this process involves an acceptor membrane complex containing the C2 domains of Psd2p, PstB2p, and Pbi1p that ligate to Scs2p and phosphatidic acid present in the donor membrane, forming a zone of apposition that facilitates PtdSer transfer.
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Affiliation(s)
- Wayne R Riekhof
- From the Department of Medicine, Program in Cell Biology, National Jewish Health, Denver, Colorado 80206 and
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48
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MAM (mitochondria-associated membranes) in mammalian cells: lipids and beyond. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1841:595-609. [PMID: 24316057 DOI: 10.1016/j.bbalip.2013.11.014] [Citation(s) in RCA: 446] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 11/21/2013] [Accepted: 11/27/2013] [Indexed: 12/15/2022]
Abstract
One mechanism by which communication between the endoplasmic reticulum (ER) and mitochondria is achieved is by close juxtaposition between these organelles via mitochondria-associated membranes (MAM). The MAM consist of a region of the ER that is enriched in several lipid biosynthetic enzyme activities and becomes reversibly tethered to mitochondria. Specific proteins are localized, sometimes transiently, in the MAM. Several of these proteins have been implicated in tethering the MAM to mitochondria. In mammalian cells, formation of these contact sites between MAM and mitochondria appears to be required for key cellular events including the transport of calcium from the ER to mitochondria, the import of phosphatidylserine into mitochondria from the ER for decarboxylation to phosphatidylethanolamine, the formation of autophagosomes, regulation of the morphology, dynamics and functions of mitochondria, and cell survival. This review focuses on the functions proposed for MAM in mediating these events in mammalian cells. In light of the apparent involvement of MAM in multiple fundamental cellular processes, recent studies indicate that impaired contact between MAM and mitochondria might underlie the pathology of several human neurodegenerative diseases, including Alzheimer's disease. Moreover, MAM has been implicated in modulating glucose homeostasis and insulin resistance, as well as in some viral infections.
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49
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Gsell M, Mascher G, Schuiki I, Ploier B, Hrastnik C, Daum G. Transcriptional response to deletion of the phosphatidylserine decarboxylase Psd1p in the yeast Saccharomyces cerevisiae. PLoS One 2013; 8:e77380. [PMID: 24146988 PMCID: PMC3795641 DOI: 10.1371/journal.pone.0077380] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 09/05/2013] [Indexed: 11/18/2022] Open
Abstract
In the yeast, Saccharomyces cerevisiae, the synthesis of the essential phospholipid phosphatidylethanolamine (PE) is accomplished by a network of reactions which comprises four different pathways. The enzyme contributing most to PE formation is the mitochondrial phosphatidylserine decarboxylase 1 (Psd1p) which catalyzes conversion of phosphatidylserine (PS) to PE. To study the genome wide effect of an unbalanced cellular and mitochondrial PE level and in particular the contribution of Psd1p to this depletion we performed a DNA microarray analysis with a ∆psd1 deletion mutant. This approach revealed that 54 yeast genes were significantly up-regulated in the absence of PSD1 compared to wild type. Surprisingly, marked down-regulation of genes was not observed. A number of different cellular processes in different subcellular compartments were affected in a ∆psd1 mutant. Deletion mutants bearing defects in all 54 candidate genes, respectively, were analyzed for their growth phenotype and their phospholipid profile. Only three mutants, namely ∆gpm2, ∆gph1 and ∆rsb1, were affected in one of these parameters. The possible link of these mutations to PE deficiency and PSD1 deletion is discussed.
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Affiliation(s)
- Martina Gsell
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Gerald Mascher
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Irmgard Schuiki
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Birgit Ploier
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Claudia Hrastnik
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Günther Daum
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
- * E-mail:
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50
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Horvath SE, Daum G. Lipids of mitochondria. Prog Lipid Res 2013; 52:590-614. [PMID: 24007978 DOI: 10.1016/j.plipres.2013.07.002] [Citation(s) in RCA: 610] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 07/31/2013] [Indexed: 01/06/2023]
Abstract
A unique organelle for studying membrane biochemistry is the mitochondrion whose functionality depends on a coordinated supply of proteins and lipids. Mitochondria are capable of synthesizing several lipids autonomously such as phosphatidylglycerol, cardiolipin and in part phosphatidylethanolamine, phosphatidic acid and CDP-diacylglycerol. Other mitochondrial membrane lipids such as phosphatidylcholine, phosphatidylserine, phosphatidylinositol, sterols and sphingolipids have to be imported. The mitochondrial lipid composition, the biosynthesis and the import of mitochondrial lipids as well as the regulation of these processes will be main issues of this review article. Furthermore, interactions of lipids and mitochondrial proteins which are highly important for various mitochondrial processes will be discussed. Malfunction or loss of enzymes involved in mitochondrial phospholipid biosynthesis lead to dysfunction of cell respiration, affect the assembly and stability of the mitochondrial protein import machinery and cause abnormal mitochondrial morphology or even lethality. Molecular aspects of these processes as well as diseases related to defects in the formation of mitochondrial membranes will be described.
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Affiliation(s)
- Susanne E Horvath
- Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, A-8010 Graz, Austria
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