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Kang H, Han AR, Zhang A, Jeong H, Koh W, Lee JM, Lee H, Jo HY, Maria-Solano MA, Bhalla M, Kwon J, Roh WS, Yang J, An HJ, Choi S, Kim HM, Lee CJ. GolpHCat (TMEM87A), a unique voltage-dependent cation channel in Golgi apparatus, contributes to Golgi-pH maintenance and hippocampus-dependent memory. Nat Commun 2024; 15:5830. [PMID: 38992057 PMCID: PMC11239671 DOI: 10.1038/s41467-024-49297-8] [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: 12/14/2023] [Accepted: 05/30/2024] [Indexed: 07/13/2024] Open
Abstract
Impaired ion channels regulating Golgi pH lead to structural alterations in the Golgi apparatus, such as fragmentation, which is found, along with cognitive impairment, in Alzheimer's disease. However, the causal relationship between altered Golgi structure and cognitive impairment remains elusive due to the lack of understanding of ion channels in the Golgi apparatus of brain cells. Here, we identify that a transmembrane protein TMEM87A, renamed Golgi-pH-regulating cation channel (GolpHCat), expressed in astrocytes and neurons that contributes to hippocampus-dependent memory. We find that GolpHCat displays unique voltage-dependent currents, which is potently inhibited by gluconate. Additionally, we gain structural insights into the ion conduction through GolpHCat at the molecular level by determining three high-resolution cryogenic-electron microscopy structures of human GolpHCat. GolpHCat-knockout mice show fragmented Golgi morphology and altered protein glycosylation and functions in the hippocampus, leading to impaired spatial memory. These findings suggest a molecular target for Golgi-related diseases and cognitive impairment.
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Affiliation(s)
- Hyunji Kang
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
- IBS School, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea
| | - Ah-Reum Han
- Center for Biomolecular and Cellular Structure, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Aihua Zhang
- Global AI Drug Discovery Center, College of Pharmacy and Graduate School of Pharmaceutical Science, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Heejin Jeong
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Korea
| | - Wuhyun Koh
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Jung Moo Lee
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Hayeon Lee
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Hee Young Jo
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Korea
| | - Miguel A Maria-Solano
- Global AI Drug Discovery Center, College of Pharmacy and Graduate School of Pharmaceutical Science, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Mridula Bhalla
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Jea Kwon
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Woo Suk Roh
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Jimin Yang
- Center for Biomolecular and Cellular Structure, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Hyun Joo An
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Korea
| | - Sun Choi
- Global AI Drug Discovery Center, College of Pharmacy and Graduate School of Pharmaceutical Science, Ewha Womans University, Seoul, 03760, Republic of Korea.
| | - Ho Min Kim
- Center for Biomolecular and Cellular Structure, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea.
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - C Justin Lee
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea.
- IBS School, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea.
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Bhatt M, Lazzarin E, Alberto-Silva AS, Domingo G, Zerlotti R, Gradisch R, Bazzone A, Sitte HH, Stockner T, Bossi E. Unveiling the crucial role of betaine: modulation of GABA homeostasis via SLC6A1 transporter (GAT1). Cell Mol Life Sci 2024; 81:269. [PMID: 38884791 PMCID: PMC11335192 DOI: 10.1007/s00018-024-05309-w] [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: 04/12/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/18/2024]
Abstract
Betaine is an endogenous osmolyte that exhibits therapeutic potential by mitigating various neurological disorders. However, the underlying cellular and molecular mechanisms responsible for its neuroprotective effects remain puzzling.In this study, we describe a possible mechanism behind the positive impact of betaine in preserving neurons from excitotoxicity. Here we demonstrate that betaine at low concentration modulates the GABA uptake by GAT1 (slc6a1), the predominant GABA transporter in the central nervous system. This modulation occurs through the temporal inhibition of the transporter, wherein prolonged occupancy by betaine impedes the swift transition of the transporter to the inward conformation. Importantly, the modulatory effect of betaine on GAT1 is reversible, as the blocking of GAT1 disappears with increased extracellular GABA. Using electrophysiology, mass spectroscopy, radiolabelled cellular assay, and molecular dynamics simulation we demonstrate that betaine has a dual role in GAT1: at mM concentration acts as a slow substrate, and at µM as a temporal blocker of GABA, when it is below its K0.5. Given this unique modulatory characteristic and lack of any harmful side effects, betaine emerges as a promising neuromodulator of the inhibitory pathways improving GABA homeostasis via GAT1, thereby conferring neuroprotection against excitotoxicity.
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Affiliation(s)
- Manan Bhatt
- Department of Biotechnology and Life Science, Laboratory of Cellular and Molecular Physiology, University of Insubria, Via J. H. Dunant 3, 21100, Varese, Italy
| | - Erika Lazzarin
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Ana Sofia Alberto-Silva
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Guido Domingo
- Department of Biotechnology and Life Science, Laboratory of Cellular and Molecular Physiology, University of Insubria, Via J. H. Dunant 3, 21100, Varese, Italy
| | - Rocco Zerlotti
- Nanion Technologies GmbH, Ganghoferstr. 70a, 80339, Munich, Germany
| | - Ralph Gradisch
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Andre Bazzone
- Nanion Technologies GmbH, Ganghoferstr. 70a, 80339, Munich, Germany
| | - Harald H Sitte
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
- Hourani Center for Applied Scientific Research, Al-Ahliyya Amman University, Amman, 19328, Jordan
- Center for Addiction Research and Science, Medical University of Vienna, 1090, Vienna, Austria
| | - Thomas Stockner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Elena Bossi
- Department of Biotechnology and Life Science, Laboratory of Cellular and Molecular Physiology, University of Insubria, Via J. H. Dunant 3, 21100, Varese, Italy.
- Centre for Neuroscience, University of Insubria, 21100, Varese, Italy.
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3
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Wang Z, Felstead HR, Troup RI, Linclau B, Williamson PTF. Lipophilicity Modulations by Fluorination Correlate with Membrane Partitioning. Angew Chem Int Ed Engl 2023; 62:e202301077. [PMID: 36932824 PMCID: PMC10946813 DOI: 10.1002/anie.202301077] [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: 01/20/2023] [Revised: 03/16/2023] [Accepted: 03/16/2023] [Indexed: 03/19/2023]
Abstract
Bioactive compounds generally need to cross membranes to arrive at their site of action. The octanol-water partition coefficient (lipophilicity, logPOW ) has proven to be an excellent proxy for membrane permeability. In modern drug discovery, logPOW and bioactivity are optimized simultaneously, for which fluorination is one of the relevant strategies. The question arises as to which extent the often subtle logP modifications resulting from different aliphatic fluorine-motif introductions also lead to concomitant membrane permeability changes, given the difference in molecular environment between octanol and (anisotropic) membranes. It was found that for a given compound class, there is excellent correlation between logPOW values with the corresponding membrane molar partitioning coefficients (logKp ); a study enabled by novel solid-state 19 F NMR MAS methodology using lipid vesicles. Our results show that the factors that cause modulation of octanol-water partition coefficients similarly affect membrane permeability.
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Affiliation(s)
- Zhong Wang
- School of ChemistryUniversity of Southampton HighfieldSouthamptonSO17 1BJUK
| | - Hannah R. Felstead
- School of ChemistryUniversity of Southampton HighfieldSouthamptonSO17 1BJUK
| | - Robert I. Troup
- School of ChemistryUniversity of Southampton HighfieldSouthamptonSO17 1BJUK
| | - Bruno Linclau
- School of ChemistryUniversity of Southampton HighfieldSouthamptonSO17 1BJUK
- Department of Organic and Macromolecular ChemistryGhent University Campus SterreKrijgslaan 281-S49000GhentBelgium
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4
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Zuzic L, Samsudin F, Shivgan AT, Raghuvamsi PV, Marzinek JK, Boags A, Pedebos C, Tulsian NK, Warwicker J, MacAry P, Crispin M, Khalid S, Anand GS, Bond PJ. Uncovering cryptic pockets in the SARS-CoV-2 spike glycoprotein. Structure 2022; 30:1062-1074.e4. [PMID: 35660160 PMCID: PMC9164293 DOI: 10.1016/j.str.2022.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 04/19/2022] [Accepted: 05/10/2022] [Indexed: 11/30/2022]
Abstract
The COVID-19 pandemic has prompted a rapid response in vaccine and drug development. Herein, we modeled a complete membrane-embedded SARS-CoV-2 spike glycoprotein and used molecular dynamics simulations with benzene probes designed to enhance discovery of cryptic pockets. This approach recapitulated lipid and host metabolite binding sites previously characterized by cryo-electron microscopy, revealing likely ligand entry routes, and uncovered a novel cryptic pocket with promising druggable properties located underneath the 617-628 loop. A full representation of glycan moieties was essential to accurately describe pocket dynamics. A multi-conformational behavior of the 617-628 loop in simulations was validated using hydrogen-deuterium exchange mass spectrometry experiments, supportive of opening and closing dynamics. The pocket is the site of multiple mutations associated with increased transmissibility found in SARS-CoV-2 variants of concern including Omicron. Collectively, this work highlights the utility of the benzene mapping approach in uncovering potential druggable sites on the surface of SARS-CoV-2 targets.
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Affiliation(s)
- Lorena Zuzic
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore; Department of Chemistry, Faculty of Science and Engineering, Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, UK
| | - Firdaus Samsudin
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore
| | - Aishwary T Shivgan
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore
| | - Palur V Raghuvamsi
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Jan K Marzinek
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore
| | - Alister Boags
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore; School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
| | - Conrado Pedebos
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Nikhil K Tulsian
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore; Department of Biochemistry, National University of Singapore, Singapore 117546, Singapore
| | - Jim Warwicker
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, UK
| | - Paul MacAry
- Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore 117546, Singapore
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Syma Khalid
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
| | - Ganesh S Anand
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA.
| | - Peter J Bond
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
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5
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Liu C, Zhu H, Zhang Y, Su M, Liu M, Zhang X, Wang X, Rong X, Wang K, Li X, Zhu B. Recent advances in Golgi-targeted small-molecule fluorescent probes. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214504] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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6
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Saud Z, Tyrrell VJ, Zaragkoulias A, Protty MB, Statkute E, Rubina A, Bentley K, White DA, Rodrigues PDS, Murphy RC, Köfeler H, Griffiths WJ, Alvarez-Jarreta J, Brown RW, Newcombe RG, Heyman J, Pritchard M, Mcleod RW, Arya A, Lynch CA, Owens D, Jenkins PV, Buurma NJ, O'Donnell VB, Thomas DW, Stanton RJ. The SARS-CoV2 envelope differs from host cells, exposes procoagulant lipids, and is disrupted in vivo by oral rinses. J Lipid Res 2022; 63:100208. [PMID: 35436499 PMCID: PMC9010312 DOI: 10.1016/j.jlr.2022.100208] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 03/23/2022] [Accepted: 04/04/2022] [Indexed: 12/14/2022] Open
Abstract
The lipid envelope of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an essential component of the virus; however, its molecular composition is undetermined. Addressing this knowledge gap could support the design of antiviral agents as well as further our understanding of viral-host protein interactions, infectivity, pathogenicity, and innate immune system clearance. Lipidomics revealed that the virus envelope comprised mainly phospholipids (PLs), with some cholesterol and sphingolipids, and with cholesterol/phospholipid ratio similar to lysosomes. Unlike cellular membranes, procoagulant amino-PLs were present on the external side of the viral envelope at levels exceeding those on activated platelets. Accordingly, virions directly promoted blood coagulation. To investigate whether these differences could enable selective targeting of the viral envelope in vivo, we tested whether oral rinses containing lipid-disrupting chemicals could reduce infectivity. Products containing PL-disrupting surfactants (such as cetylpyridinium chloride) met European virucidal standards in vitro; however, components that altered the critical micelle concentration reduced efficacy, and products containing essential oils, povidone-iodine, or chlorhexidine were ineffective. This result was recapitulated in vivo, where a 30-s oral rinse with cetylpyridinium chloride mouthwash eliminated live virus in the oral cavity of patients with coronavirus disease 19 for at least 1 h, whereas povidone-iodine and saline mouthwashes were ineffective. We conclude that the SARS-CoV-2 lipid envelope i) is distinct from the host plasma membrane, which may enable design of selective antiviral approaches; ii) contains exposed phosphatidylethanolamine and phosphatidylserine, which may influence thrombosis, pathogenicity, and inflammation; and iii) can be selectively targeted in vivo by specific oral rinses.
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Affiliation(s)
- Zack Saud
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Victoria J Tyrrell
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Andreas Zaragkoulias
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Majd B Protty
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Evelina Statkute
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Anzelika Rubina
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Kirsten Bentley
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Daniel A White
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | | | - Robert C Murphy
- Department of Pharmacology, University of Colorado Denver, Aurora, CO, USA
| | - Harald Köfeler
- Core Facility Mass Spectrometry, Medical University of Graz, Graz, Austria
| | | | - Jorge Alvarez-Jarreta
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Richard William Brown
- ENT Department, Betsi Cadwaladr University Health Board, Wrexham Maelor Hospital, Wrexham, United Kingdom
| | - Robert G Newcombe
- Division of Population Medicine, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - James Heyman
- Division of Surgery, Cardiff and Vale University Health Board, Cardiff, United Kingdom
| | - Manon Pritchard
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff, United Kingdom
| | - Robert Wj Mcleod
- Division of Surgery, Cardiff and Vale University Health Board, Cardiff, United Kingdom
| | - Arvind Arya
- ENT Department, Betsi Cadwaladr University Health Board, Wrexham Maelor Hospital, Wrexham, United Kingdom
| | - Ceri-Ann Lynch
- Anaesthetics and Critical Care Directorate, Cwm Taf University Health Board, Royal Glamorgan Hospital, Llantrisant, United Kingdom
| | - David Owens
- Division of Surgery, Cardiff and Vale University Health Board, Cardiff, United Kingdom
| | - P Vince Jenkins
- Haemostasis Diagnosis and Research, University Hospital Wales, Cardiff, United Kingdom
| | - Niklaas J Buurma
- Physical Organic Chemistry Centre, School of Chemistry, Cardiff University, Cardiff, United Kingdom
| | - Valerie B O'Donnell
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom.
| | - David W Thomas
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff, United Kingdom.
| | - Richard J Stanton
- Division of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom.
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Marques-Pereira C, Pires MN, Gouveia RP, Pereira NN, Caniceiro AB, Rosário-Ferreira N, Moreira IS. SARS-CoV-2 Membrane Protein: From Genomic Data to Structural New Insights. Int J Mol Sci 2022; 23:2986. [PMID: 35328409 PMCID: PMC8948900 DOI: 10.3390/ijms23062986] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/07/2022] [Accepted: 03/09/2022] [Indexed: 01/27/2023] Open
Abstract
Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2) is composed of four structural proteins and several accessory non-structural proteins. SARS-CoV-2's most abundant structural protein, Membrane (M) protein, has a pivotal role both during viral infection cycle and host interferon antagonism. This is a highly conserved viral protein, thus an interesting and suitable target for drug discovery. In this paper, we explain the structural nature of M protein homodimer. To do so, we developed and applied a detailed and robust in silico workflow to predict M protein dimeric structure, membrane orientation, and interface characterization. Single Nucleotide Polymorphisms (SNPs) in M protein were retrieved from over 1.2 M SARS-CoV-2 genomes and proteins from the Global Initiative on Sharing All Influenza Data (GISAID) database, 91 of which were located at the predicted dimer interface. Among those, we identified SNPs in Variants of Concern (VOC) and Variants of Interest (VOI). Binding free energy differences were evaluated for dimer interfacial SNPs to infer mutant protein stabilities. A few high-prevalent mutated residues were found to be especially relevant in VOC and VOI. This realization may be a game-changer to structure-driven formulation of new therapeutics for SARS-CoV-2.
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Affiliation(s)
- Catarina Marques-Pereira
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-535 Coimbra, Portugal; (C.M.-P.); (M.N.P.); (R.P.G.); (N.N.P.); (A.B.C.); (N.R.-F.)
- IIIs—Institute for Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal
| | - Manuel N. Pires
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-535 Coimbra, Portugal; (C.M.-P.); (M.N.P.); (R.P.G.); (N.N.P.); (A.B.C.); (N.R.-F.)
- Department of Sciences, University of Porto, 4169-007 Porto, Portugal
| | - Raquel P. Gouveia
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-535 Coimbra, Portugal; (C.M.-P.); (M.N.P.); (R.P.G.); (N.N.P.); (A.B.C.); (N.R.-F.)
| | - Nádia N. Pereira
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-535 Coimbra, Portugal; (C.M.-P.); (M.N.P.); (R.P.G.); (N.N.P.); (A.B.C.); (N.R.-F.)
| | - Ana B. Caniceiro
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-535 Coimbra, Portugal; (C.M.-P.); (M.N.P.); (R.P.G.); (N.N.P.); (A.B.C.); (N.R.-F.)
| | - Nícia Rosário-Ferreira
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-535 Coimbra, Portugal; (C.M.-P.); (M.N.P.); (R.P.G.); (N.N.P.); (A.B.C.); (N.R.-F.)
- CQC—Coimbra Chemistry Center, Chemistry Department, Faculty of Science and Technology, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Irina S. Moreira
- Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology, University of Coimbra, 3004-535 Coimbra, Portugal
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8
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Rodal Canales FJ, Pérez-Campos Mayoral L, Hernández-Huerta MT, Sánchez Navarro LM, Matias-Cervantes CA, Martínez Cruz M, Cruz Parada E, Zenteno E, Ramos-Martínez EG, Pérez-Campos Mayoral E, Romero Díaz C, Pérez-Campos E. Interaction of Spike protein and lipid membrane of SARS-CoV-2 with Ursodeoxycholic acid, an in-silico analysis. Sci Rep 2021; 11:22288. [PMID: 34782703 PMCID: PMC8593036 DOI: 10.1038/s41598-021-01705-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 11/01/2021] [Indexed: 12/18/2022] Open
Abstract
Numerous repositioned drugs have been sought to decrease the severity of SARS-CoV-2 infection. It is known that among its physicochemical properties, Ursodeoxycholic Acid (UDCA) has a reduction in surface tension and cholesterol solubilization, it has also been used to treat cholesterol gallstones and viral hepatitis. In this study, molecular docking was performed with the SARS-CoV-2 Spike protein and UDCA. In order to confirm this interaction, we used Molecular Dynamics (MD) in “SARS-CoV-2 Spike protein-UDCA”. Using another system, we also simulated MD with six UDCA residues around the Spike protein at random, naming this “SARS-CoV-2 Spike protein-6UDCA”. Finally, we evaluated the possible interaction between UDCA and different types of membranes, considering the possible membrane conformation of SARS-CoV-2, this was named “SARS-CoV-2 membrane-UDCA”. In the “SARS-CoV-2 Spike protein-UDCA”, we found that UDCA exhibits affinity towards the central region of the Spike protein structure of − 386.35 kcal/mol, in a region with 3 alpha helices, which comprises residues from K986 to C1032 of each monomer. MD confirmed that UDCA remains attached and occasionally forms hydrogen bonds with residues R995 and T998. In the presence of UDCA, we observed that the distances between residues atoms OG1 and CG2 of T998 in the monomers A, B, and C in the prefusion state do not change and remain at 5.93 ± 0.62 and 7.78 ± 0.51 Å, respectively, compared to the post-fusion state. Next, in “SARS-CoV-2 Spike protein-6UDCA”, the three UDCA showed affinity towards different regions of the Spike protein, but only one of them remained bound to the region between the region's heptad repeat 1 and heptad repeat 2 (HR1 and HR2) for 375 ps of the trajectory. The RMSD of monomer C was the smallest of the three monomers with a value of 2.89 ± 0.32, likewise, the smallest RMSF was also of the monomer C (2.25 ± 056). In addition, in the simulation of “SARS-CoV-2 membrane-UDCA”, UDCA had a higher affinity toward the virion-like membrane; where three of the four residues remained attached once they were close (5 Å, to the centre of mass) to the membrane by 30 ns. However, only one of them remained attached to the plasma-like membrane and this was in a cluster of cholesterol molecules. We have shown that UDCA interacts in two distinct regions of Spike protein sequences. In addition, UDCA tends to stay bound to the membrane, which could potentially reduce the internalization of SARS-CoV-2 in the host cell.
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Affiliation(s)
- Francisco Javier Rodal Canales
- Research Centre Faculty of Medicine UNAM-UABJO, Faculty of Medicine and Surgery, Autonomous University "Benito Juárez" of Oaxaca, 68020, Oaxaca, Mexico
| | - Laura Pérez-Campos Mayoral
- Research Centre Faculty of Medicine UNAM-UABJO, Faculty of Medicine and Surgery, Autonomous University "Benito Juárez" of Oaxaca, 68020, Oaxaca, Mexico
| | | | - Luis Manuel Sánchez Navarro
- Research Centre Faculty of Medicine UNAM-UABJO, Faculty of Medicine and Surgery, Autonomous University "Benito Juárez" of Oaxaca, 68020, Oaxaca, Mexico
| | | | | | - Eli Cruz Parada
- National Technology of Mexico/IT Oaxaca, 68030, Oaxaca, Mexico
| | - Edgar Zenteno
- Faculty of Medicine, National Autonomous University of Mexico, 04360, Mexico City, Mexico
| | | | - Eduardo Pérez-Campos Mayoral
- Research Centre Faculty of Medicine UNAM-UABJO, Faculty of Medicine and Surgery, Autonomous University "Benito Juárez" of Oaxaca, 68020, Oaxaca, Mexico
| | - Carlos Romero Díaz
- Research Centre Faculty of Medicine UNAM-UABJO, Faculty of Medicine and Surgery, Autonomous University "Benito Juárez" of Oaxaca, 68020, Oaxaca, Mexico.
| | - Eduardo Pérez-Campos
- National Technology of Mexico/IT Oaxaca, 68030, Oaxaca, Mexico. .,Clinical Pathology Laboratory, "Eduardo Pérez Ortega", 68000, Oaxaca, Mexico.
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9
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Allen JD, Chawla H, Samsudin F, Zuzic L, Shivgan AT, Watanabe Y, He WT, Callaghan S, Song G, Yong P, Brouwer PJM, Song Y, Cai Y, Duyvesteyn HME, Malinauskas T, Kint J, Pino P, Wurm MJ, Frank M, Chen B, Stuart DI, Sanders RW, Andrabi R, Burton DR, Li S, Bond PJ, Crispin M. Site-Specific Steric Control of SARS-CoV-2 Spike Glycosylation. Biochemistry 2021; 60:2153-2169. [PMID: 34213308 PMCID: PMC8262170 DOI: 10.1021/acs.biochem.1c00279] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/18/2021] [Indexed: 02/08/2023]
Abstract
A central tenet in the design of vaccines is the display of native-like antigens in the elicitation of protective immunity. The abundance of N-linked glycans across the SARS-CoV-2 spike protein is a potential source of heterogeneity among the many different vaccine candidates under investigation. Here, we investigate the glycosylation of recombinant SARS-CoV-2 spike proteins from five different laboratories and compare them against S protein from infectious virus, cultured in Vero cells. We find patterns that are conserved across all samples, and this can be associated with site-specific stalling of glycan maturation that acts as a highly sensitive reporter of protein structure. Molecular dynamics simulations of a fully glycosylated spike support a model of steric restrictions that shape enzymatic processing of the glycans. These results suggest that recombinant spike-based SARS-CoV-2 immunogen glycosylation reproducibly recapitulates signatures of viral glycosylation.
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Affiliation(s)
- Joel D. Allen
- School
of Biological Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
| | - Himanshi Chawla
- School
of Biological Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
| | - Firdaus Samsudin
- Bioinformatics
Institute, Agency for Science, Technology
and Research (A*STAR), Singapore 138671
| | - Lorena Zuzic
- Bioinformatics
Institute, Agency for Science, Technology
and Research (A*STAR), Singapore 138671
- Department
of Chemistry, Faculty of Science and Engineering, Manchester Institute
of Biotechnology, The University of Manchester, Manchester M1 7DN, U.K.
| | - Aishwary Tukaram Shivgan
- Bioinformatics
Institute, Agency for Science, Technology
and Research (A*STAR), Singapore 138671
- Department
of Biological Sciences, National University
of Singapore, Singapore 117543
| | - Yasunori Watanabe
- School
of Biological Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
| | - Wan-ting He
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Sean Callaghan
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Ge Song
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Peter Yong
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Philip J. M. Brouwer
- Department
of Medical Microbiology, Amsterdam UMC,
University of Amsterdam, Amsterdam Infection & Immunity Institute, 1007 MB Amsterdam, The Netherlands
| | - Yutong Song
- Tsinghua-Peking
Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Beijing
Advanced Innovation Center for Structural Biology and Frontier Research
Center for Biological Structure, Beijing 100084, China
| | - Yongfei Cai
- Division
of Molecular Medicine, Boston Children’s
Hospital, 3 Blackfan
Street, Boston, Massachusetts 02115, United States
| | - Helen M. E. Duyvesteyn
- Division
of Structural Biology, University of Oxford,
The Wellcome Centre for Human Genetics, Headington, Oxford OX3 7BN, U.K.
| | - Tomas Malinauskas
- Division
of Structural Biology, University of Oxford,
The Wellcome Centre for Human Genetics, Headington, Oxford OX3 7BN, U.K.
| | - Joeri Kint
- ExcellGene SA, CH1870 Monthey, Switzerland
| | - Paco Pino
- ExcellGene SA, CH1870 Monthey, Switzerland
| | | | - Martin Frank
- Biognos AB, Generatorsgatan
1, 41705 Göteborg, Sweden
| | - Bing Chen
- Division
of Molecular Medicine, Boston Children’s
Hospital, 3 Blackfan
Street, Boston, Massachusetts 02115, United States
- Department
of Pediatrics, Harvard Medical School, 3 Blackfan Street, Boston, Massachusetts 02115, United States
| | - David I. Stuart
- Division
of Structural Biology, University of Oxford,
The Wellcome Centre for Human Genetics, Headington, Oxford OX3 7BN, U.K.
- Diamond Light Source Ltd., Harwell Science
& Innovation Campus, Didcot OX11 0DE, U.K.
| | - Rogier W. Sanders
- Department
of Medical Microbiology, Amsterdam UMC,
University of Amsterdam, Amsterdam Infection & Immunity Institute, 1007 MB Amsterdam, The Netherlands
- Department
of Microbiology and Immunology, Weill Medical
College of Cornell University, New York, New York 10065, United States
| | - Raiees Andrabi
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Dennis R. Burton
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
- Ragon Institute of Massachusetts General
Hospital, Massachusetts
Institute of Technology, and Harvard University, Cambridge, Massachusetts 02139, United States
| | - Sai Li
- Tsinghua-Peking
Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Beijing
Advanced Innovation Center for Structural Biology and Frontier Research
Center for Biological Structure, Beijing 100084, China
| | - Peter J. Bond
- Bioinformatics
Institute, Agency for Science, Technology
and Research (A*STAR), Singapore 138671
- Department
of Biological Sciences, National University
of Singapore, Singapore 117543
| | - Max Crispin
- School
of Biological Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
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10
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Szöllősi D, Stockner T. Investigating the Mechanism of Sodium Binding to SERT Using Direct Simulations. Front Cell Neurosci 2021; 15:673782. [PMID: 34040506 PMCID: PMC8141550 DOI: 10.3389/fncel.2021.673782] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/14/2021] [Indexed: 11/13/2022] Open
Abstract
The serotonin transporter (SERT) terminates neurotransmission by transporting serotonin from the synapse into the pre-synaptic nerve terminal. Altered SERT function leads to several neurological diseases including depression, anxiety, mood disorders, and attention deficit hyperactivity disorders (ADHD). Accordingly SERT is the target for their pharmacological treatments, but also targeted by multiple drugs of abuse. Transport of serotonin by SERT is energized by the transmembrane electrochemical gradient of sodium. We used extensive molecular dynamics simulations to investigate the process of sodium binding to SERT, which is the first step in the transport cycle that leads to serotonin uptake. Comparing data from 51 independent simulations, we find a remarkably well-defined path for sodium entry and could identify two transient binding sites, while observing binding kinetics that are comparable to experimental data. Importantly, the structure and dynamics of the sodium binding sites indicate that sodium binding is accompanied by an induced-fit mechanism that leads to new conformations and reduces local dynamics.
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Affiliation(s)
- Dániel Szöllősi
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Thomas Stockner
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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11
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PHLPPing the balance: restoration of protein kinase C in cancer. Biochem J 2021; 478:341-355. [PMID: 33502516 DOI: 10.1042/bcj20190765] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/22/2020] [Accepted: 01/04/2021] [Indexed: 12/28/2022]
Abstract
Protein kinase signalling, which transduces external messages to mediate cellular growth and metabolism, is frequently deregulated in human disease, and specifically in cancer. As such, there are 77 kinase inhibitors currently approved for the treatment of human disease by the FDA. Due to their historical association as the receptors for the tumour-promoting phorbol esters, PKC isozymes were initially targeted as oncogenes in cancer. However, a meta-analysis of clinical trials with PKC inhibitors in combination with chemotherapy revealed that these treatments were not advantageous, and instead resulted in poorer outcomes and greater adverse effects. More recent studies suggest that instead of inhibiting PKC, therapies should aim to restore PKC function in cancer: cancer-associated PKC mutations are generally loss-of-function and high PKC protein is protective in many cancers, including most notably KRAS-driven cancers. These recent findings have reframed PKC as having a tumour suppressive function. This review focusses on a potential new mechanism of restoring PKC function in cancer - through targeting of its negative regulator, the Ser/Thr protein phosphatase PHLPP. This phosphatase regulates PKC steady-state levels by regulating the phosphorylation of a key site, the hydrophobic motif, whose phosphorylation is necessary for the stability of the enzyme. We also consider whether the phosphorylation of the potent oncogene KRAS provides a mechanism by which high PKC expression may be protective in KRAS-driven human cancers.
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12
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Nanda P, Ghosh A. Genome Scale-Differential Flux Analysis reveals deregulation of lung cell metabolism on SARS-CoV-2 infection. PLoS Comput Biol 2021; 17:e1008860. [PMID: 33835998 PMCID: PMC8034727 DOI: 10.1371/journal.pcbi.1008860] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/09/2021] [Indexed: 12/27/2022] Open
Abstract
The COVID-19 pandemic is posing an unprecedented threat to the whole world. In this regard, it is absolutely imperative to understand the mechanism of metabolic reprogramming of host human cells by SARS-CoV-2. A better understanding of the metabolic alterations would aid in design of better therapeutics to deal with COVID-19 pandemic. We developed an integrated genome-scale metabolic model of normal human bronchial epithelial cells (NHBE) infected with SARS-CoV-2 using gene-expression and macromolecular make-up of the virus. The reconstructed model predicts growth rates of the virus in high agreement with the experimental measured values. Furthermore, we report a method for conducting genome-scale differential flux analysis (GS-DFA) in context-specific metabolic models. We apply the method to the context-specific model and identify severely affected metabolic modules predominantly comprising of lipid metabolism. We conduct an integrated analysis of the flux-altered reactions, host-virus protein-protein interaction network and phospho-proteomics data to understand the mechanism of flux alteration in host cells. We show that several enzymes driving the altered reactions inferred by our method to be directly interacting with viral proteins and also undergoing differential phosphorylation under diseased state. In case of SARS-CoV-2 infection, lipid metabolism particularly fatty acid oxidation, cholesterol biosynthesis and beta-oxidation cycle along with arachidonic acid metabolism are predicted to be most affected which confirms with clinical metabolomics studies. GS-DFA can be applied to existing repertoire of high-throughput proteomic or transcriptomic data in diseased condition to understand metabolic deregulation at the level of flux. Metabolic flux analysis in disease biology is opening up new avenues for therapeutic interventions. Numerous diseases lead to disturbance in the metabolic homeostasis and it is becoming increasingly important to be able to quantify the difference in interaction under normal and diseased condition. While genome-scale metabolic models have been used to study those differences, there are limited methods to probe into the differences in flux between these two conditions. Our method of conducting a differential flux analysis can be leveraged to find which reactions are altered between the diseased and normal state. We applied this to study the altered reactions in the case of SARS-CoV-2 infection. We further corroborated our results with other multi-omics studies and found significant agreement.
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Affiliation(s)
- Piyush Nanda
- Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal, India
| | - Amit Ghosh
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, West Bengal, India
- P.K. Sinha Centre for Bioenergy and Renewables, Indian Institute of Technology Kharagpur, West Bengal, India
- * E-mail:
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13
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GM130 regulates pulmonary surfactant protein secretion in alveolar type II cells. SCIENCE CHINA-LIFE SCIENCES 2021; 65:193-205. [PMID: 33740186 DOI: 10.1007/s11427-020-1875-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 01/05/2021] [Indexed: 12/14/2022]
Abstract
Pulmonary surfactant is a lipid-protein complex secreted by alveolar type II epithelial cells and is essential for the maintenance of the delicate structure of mammalian alveoli to promote efficient gas exchange across the air-liquid barrier. The Golgi apparatus plays an important role in pulmonary surfactant modification and secretory trafficking. However, the physiological function of the Golgi apparatus in the transport of pulmonary surfactants is unclear. In the present study, deletion of GM130, which encodes for a matrix protein of the cis-Golgi cisternae, was shown to induce the disruption of the Golgi structure leading to impaired secretion of lung surfactant proteins and lipids. Specifically, the results of in vitro and in vivo analysis indicated that the loss of GM130 resulted in trapping of Sftpa in the endoplasmic reticulum, Sftpb and Sftpc accumulation in the Golgi apparatus, and an increase in the compensatory secretion of Sftpd. Moreover, global and epithelial-specific GM130 knockout in mice resulted in an enlargement of alveolar airspace and an increase in alveolar epithelial autophagy; however, surfactant repletion partially rescued the enlarged airspace defects in GM130-deficient mice. Therefore, our results demonstrate that GM130 and the mammalian Golgi apparatus play a critical role in the control of surfactant protein secretion in pulmonary epithelial cells.
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14
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Allen JD, Chawla H, Samsudin F, Zuzic L, Shivgan AT, Watanabe Y, He WT, Callaghan S, Song G, Yong P, Brouwer PJM, Song Y, Cai Y, Duyvesteyn HME, Malinauskas T, Kint J, Pino P, Wurm MJ, Frank M, Chen B, Stuart DI, Sanders RW, Andrabi R, Burton DR, Li S, Bond PJ, Crispin M. Site-specific steric control of SARS-CoV-2 spike glycosylation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.03.08.433764. [PMID: 33758835 PMCID: PMC7986994 DOI: 10.1101/2021.03.08.433764] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
A central tenet in the design of vaccines is the display of native-like antigens in the elicitation of protective immunity. The abundance of N-linked glycans across the SARS-CoV-2 spike protein is a potential source of heterogeneity between the many different vaccine candidates under investigation. Here, we investigate the glycosylation of recombinant SARS-CoV-2 spike proteins from five different laboratories and compare them against infectious virus S protein. We find patterns which are conserved across all samples and this can be associated with site-specific stalling of glycan maturation which act as a highly sensitive reporter of protein structure. Molecular dynamics (MD) simulations of a fully glycosylated spike support s a model of steric restrictions that shape enzymatic processing of the glycans. These results suggest that recombinant spike-based SARS-CoV-2 immunogen glycosylation reproducibly recapitulates signatures of viral glycosylation.
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15
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Raghuvamsi PV, Tulsian NK, Samsudin F, Qian X, Purushotorman K, Yue G, Kozma MM, Hwa WY, Lescar J, Bond PJ, MacAry PA, Anand GS. SARS-CoV-2 S protein:ACE2 interaction reveals novel allosteric targets. eLife 2021; 10:63646. [PMID: 33554856 PMCID: PMC7932696 DOI: 10.7554/elife.63646] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 02/05/2021] [Indexed: 12/19/2022] Open
Abstract
The spike (S) protein is the main handle for SARS-CoV-2 to enter host cells via surface angiotensin-converting enzyme 2 (ACE2) receptors. How ACE2 binding activates proteolysis of S protein is unknown. Here, using amide hydrogen–deuterium exchange mass spectrometry and molecular dynamics simulations, we have mapped the S:ACE2 interaction interface and uncovered long-range allosteric propagation of ACE2 binding to sites necessary for host-mediated proteolysis of S protein, critical for viral host entry. Unexpectedly, ACE2 binding enhances dynamics at a distal S1/S2 cleavage site and flanking protease docking site ~27 Å away while dampening dynamics of the stalk hinge (central helix and heptad repeat [HR]) regions ~130 Å away. This highlights that the stalk and proteolysis sites of the S protein are dynamic hotspots in the prefusion state. Our findings provide a dynamics map of the S:ACE2 interface in solution and also offer mechanistic insights into how ACE2 binding is allosterically coupled to distal proteolytic processing sites and viral–host membrane fusion. Thus, protease docking sites flanking the S1/S2 cleavage site represent alternate allosteric hotspot targets for potential therapeutic development.
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Affiliation(s)
- Palur V Raghuvamsi
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
| | - Nikhil K Tulsian
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Centre for Life Sciences, Department of Biochemistry, National University of Singapore, Singapore, Singapore
| | - Firdaus Samsudin
- Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
| | - Xinlei Qian
- Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore, Singapore
| | - Kiren Purushotorman
- Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore, Singapore
| | - Gu Yue
- Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore, Singapore
| | - Mary M Kozma
- Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore, Singapore
| | - Wong Y Hwa
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Julien Lescar
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Peter J Bond
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Bioinformatics Institute, Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
| | - Paul A MacAry
- Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore, Singapore
| | - Ganesh S Anand
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Current address: Department of Chemistry, Department of Biochemistry and Molecular Biology, Center for Infectious Disease Dynamics -Huck Institute of the Life Sciences, The Pennsylvania State University, University Park, United States
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16
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O'Donnell VB, Thomas D, Stanton R, Maillard JY, Murphy RC, Jones SA, Humphreys I, Wakelam MJO, Fegan C, Wise MP, Bosch A, Sattar SA. Potential Role of Oral Rinses Targeting the Viral Lipid Envelope in SARS-CoV-2 Infection. FUNCTION 2020; 1:zqaa002. [PMID: 33215159 PMCID: PMC7239187 DOI: 10.1093/function/zqaa002] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/04/2020] [Accepted: 05/08/2020] [Indexed: 01/06/2023] Open
Abstract
Emerging studies increasingly demonstrate the importance of the throat and salivary glands as sites of virus replication and transmission in early COVID-19 disease. SARS-CoV-2 is an enveloped virus, characterized by an outer lipid membrane derived from the host cell from which it buds. While it is highly sensitive to agents that disrupt lipid biomembranes, there has been no discussion about the potential role of oral rinsing in preventing transmission. Here, we review known mechanisms of viral lipid membrane disruption by widely available dental mouthwash components that include ethanol, chlorhexidine, cetylpyridinium chloride, hydrogen peroxide, and povidone-iodine. We also assess existing formulations for their potential ability to disrupt the SARS-CoV-2 lipid envelope, based on their concentrations of these agents, and conclude that several deserve clinical evaluation. We highlight that already published research on other enveloped viruses, including coronaviruses, directly supports the idea that oral rinsing should be considered as a potential way to reduce transmission of SARS-CoV-2. Research to test this could include evaluating existing or specifically tailored new formulations in well-designed viral inactivation assays, then in clinical trials. Population-based interventions could be undertaken with available mouthwashes, with active monitoring of outcome to determine efficacy. This is an under-researched area of major clinical need.
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Affiliation(s)
| | - David Thomas
- Systems Immunity Research Institute.,School of Dentistry
| | | | - Jean-Yves Maillard
- Systems Immunity Research Institute.,School of Pharmacy and Pharmaceutical Sciences, Cardiff University, CF14 4XN, UK
| | - Robert C Murphy
- Department of Pharmacology, University of Colorado Denver, Aurora, CO 80045, USA
| | - Simon A Jones
- Systems Immunity Research Institute.,School of Medicine
| | - Ian Humphreys
- Systems Immunity Research Institute.,School of Medicine
| | | | | | - Matt P Wise
- University Hospital of Wales, Cardiff, CF14 4XW, UK
| | - Albert Bosch
- Enteric Virus Laboratory, University of Barcelona, 08028 Barcelona, Spain
| | - Syed A Sattar
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5 Canada
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17
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Zhu H, Liang C, Cai X, Zhang H, Liu C, Jia P, Li Z, Yu Y, Zhang X, Sheng W, Zhu B. Rational Design of a Targetable Fluorescent Probe for Visualizing H2S Production under Golgi Stress Response Elicited by Monensin. Anal Chem 2019; 92:1883-1889. [DOI: 10.1021/acs.analchem.9b04009] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Hanchuang Zhu
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Changxu Liang
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Xinyu Cai
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Hanming Zhang
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Caiyun Liu
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Pan Jia
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Zilu Li
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Yamin Yu
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Xue Zhang
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Wenlong Sheng
- Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250103, China
| | - Baocun Zhu
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
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18
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Parker JL, Corey RA, Stansfeld PJ, Newstead S. Structural basis for substrate specificity and regulation of nucleotide sugar transporters in the lipid bilayer. Nat Commun 2019; 10:4657. [PMID: 31604945 PMCID: PMC6789118 DOI: 10.1038/s41467-019-12673-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 09/24/2019] [Indexed: 01/21/2023] Open
Abstract
Nucleotide sugars are the activated form of monosaccharides used by glycosyltransferases during glycosylation. In eukaryotes the SLC35 family of solute carriers are responsible for their selective uptake into the Endoplasmic Reticulum or Golgi apparatus. The structure of the yeast GDP-mannose transporter, Vrg4, revealed a requirement for short chain lipids and a marked difference in transport rate between the nucleotide sugar and nucleoside monophosphate, suggesting a complex network of regulatory elements control transport into these organelles. Here we report the crystal structure of the GMP bound complex of Vrg4, revealing the molecular basis for GMP recognition and transport. Molecular dynamics, combined with biochemical analysis, reveal a lipid mediated dimer interface and mechanism for coordinating structural rearrangements during transport. Together these results provide further insight into how SLC35 family transporters function within the secretory pathway and sheds light onto the role that membrane lipids play in regulating transport across the membrane.
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Affiliation(s)
- Joanne L Parker
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
| | - Robin A Corey
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Phillip J Stansfeld
- School of Life Sciences & Department of Chemistry, The University of Warwick, Coventry, CV4 7AL, UK.
| | - Simon Newstead
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
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19
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Pannwitt S, Stangl M, Schneider D. Lipid Binding Controls Dimerization of the Coat Protein p24 Transmembrane Helix. Biophys J 2019; 117:1554-1562. [PMID: 31627840 DOI: 10.1016/j.bpj.2019.09.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 09/05/2019] [Accepted: 09/09/2019] [Indexed: 10/25/2022] Open
Abstract
Coat protein (COP) I and COP II complexes are involved in the transport of proteins between the endoplasmic reticulum and the Golgi apparatus in eukaryotic cells. The formation of COP I/II complexes at membrane surfaces is an early step in vesicle formation and is mastered by p24, a type I transmembrane protein. Oligomerization of p24 monomers was suggested to be mediated and/or stabilized via interactions within the transmembrane domain, and the p24 transmembrane helix appears to selectively bind a single sphingomyelin C18:0 molecule. Furthermore, a potential cholesterol-binding sequence has also been predicted in the p24 transmembrane domain. Thus, sphingomyelin and/or cholesterol binding to the transmembrane domain might directly control the oligomeric state of p24 and, thus, COP vesicle formation. In this study, we show that sequence-specific dimerization of the p24 transmembrane helix is mediated by a LQ7 motif, with Gln187 being of special importance. Whereas cholesterol has no direct impact on p24 dimerization, binding of the sphingolipid can clearly control dimerization of p24 in rigid membrane regions. We suggest that specific binding of a sphingolipid to the p24 transmembrane helix affects p24 dimerization in membranes with increased cholesterol contents. A clearly defined p24 dimerization propensity likely is crucial for the p24 activity, which involves shuttling in between the endoplasmic reticulum and the Golgi membrane, in which cholesterol and SM C18:0 concentrations differ.
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Affiliation(s)
- Stefanie Pannwitt
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Michael Stangl
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Dirk Schneider
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany.
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20
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Welch LG, Munro S. A tale of short tails, through thick and thin: investigating the sorting mechanisms of Golgi enzymes. FEBS Lett 2019; 593:2452-2465. [DOI: 10.1002/1873-3468.13553] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/18/2019] [Accepted: 07/19/2019] [Indexed: 01/28/2023]
Affiliation(s)
- Lawrence G. Welch
- MRC Laboratory of Molecular Biology Francis Crick Avenue Cambridge UK
| | - Sean Munro
- MRC Laboratory of Molecular Biology Francis Crick Avenue Cambridge UK
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21
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Parker JL, Newstead S. Gateway to the Golgi: molecular mechanisms of nucleotide sugar transporters. Curr Opin Struct Biol 2019; 57:127-134. [PMID: 30999236 DOI: 10.1016/j.sbi.2019.03.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 03/09/2019] [Accepted: 03/12/2019] [Indexed: 12/16/2022]
Abstract
The Golgi apparatus plays a central role in the secretory pathway as a hub for posttranslational modification, protein sorting and quality control. To date, there is little structural or biochemical information concerning the function of transporters that reside within this organelle. The SLC35 family of nucleotide sugar transporters link the synthesis of activated sugar molecules and sulfate in the cytoplasm, with the luminal transferases that catalyse their attachment to proteins and lipids during glycosylation and sulfation. A recent crystal structure of the GDP-mannose transporter has revealed key sequence motifs that direct ligand recognition and transport. Further biochemical studies unexpectedly found a requirement for short chain lipids in activating the transporter, suggesting a possible route for transport regulation within the Golgi.
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Affiliation(s)
- Joanne L Parker
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
| | - Simon Newstead
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
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22
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Luo J, Jiang LY, Yang H, Song BL. Intracellular Cholesterol Transport by Sterol Transfer Proteins at Membrane Contact Sites. Trends Biochem Sci 2019; 44:273-292. [DOI: 10.1016/j.tibs.2018.10.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/06/2018] [Accepted: 10/10/2018] [Indexed: 12/20/2022]
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Casein interaction with lipid membranes: Are the phase state or charge density of the phospholipids affecting protein adsorption? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2588-2598. [DOI: 10.1016/j.bbamem.2018.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/11/2018] [Accepted: 09/26/2018] [Indexed: 01/03/2023]
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Ray A, Gräter F, Thukral L. Probing molecular forces in multi-component physiological membranes. Phys Chem Chem Phys 2018; 20:2155-2161. [PMID: 29177331 DOI: 10.1039/c7cp05981g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Biological membranes are remarkably heterogeneous, composed of diverse lipid mixtures with distinct chemical structure and composition. By combining molecular dynamics simulations and the newly developed Lipid-Force Distribution Analysis (L-FDA), we explore force transmission in complex multi-component membrane models mimicking eukaryotic organelles. We found that the chemical-moiety based segmentation at membrane interfaces revealed a distinctive distribution of bonded and non-bonded forces in diverse membrane environment. Our molecular stress analysis could have far-reaching implications in describing the relationship between membrane mechanical properties and functional states of chemically distinct lipids.
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Affiliation(s)
- Arjun Ray
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India.
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25
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Structural basis of nucleotide sugar transport across the Golgi membrane. Nature 2017; 551:521-524. [PMID: 29143814 PMCID: PMC5701743 DOI: 10.1038/nature24464] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 09/27/2017] [Indexed: 12/15/2022]
Abstract
Glycosylation is a fundamental cellular process that in eukaryotes occurs
in the lumen of both the Golgi apparatus and endoplasmic reticulum 1. Nucleotide sugar transporters (NSTs) are
an essential component of the glyscosylation pathway, providing the diverse
range of substrates required for the glycosyltransferases 2,3. NSTs are linked
to several developmental and immune disorders in humans and in pathogenic
microbes play an important role in virulence 4–8. How NSTs recognise
and transport activated monosaccharides however is currently unclear. Here we
present the first crystal structure of an NST, the GDP-mannose transporter Vrg4,
in both the substrate free and bound states. A hitherto unobserved requirement
for short chain lipids in activating the transporter supports a model for
regulation within the highly dynamic membranes of the Golgi apparatus. Our
results provide a structural basis for understanding nucleotide sugar
recognition and provide insights into the transport and regulatory mechanism for
this family of intracellular transporters.
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Nakao H, Ikeda K, Ishihama Y, Nakano M. Membrane-Spanning Sequences in Endoplasmic Reticulum Proteins Promote Phospholipid Flip-Flop. Biophys J 2017; 110:2689-2697. [PMID: 27332127 DOI: 10.1016/j.bpj.2016.05.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/30/2016] [Accepted: 05/09/2016] [Indexed: 10/21/2022] Open
Abstract
The mechanism whereby phospholipids rapidly flip-flop in the endoplasmic reticulum (ER) membrane remains unknown. We previously demonstrated that the presence of a hydrophilic residue in the center of the model transmembrane peptide sequence effectively promoted phospholipid flip-flop and that hydrophilic residues composed 4.5% of the central regions of the membrane-spanning sequences of human ER membrane proteins predicted by SOSUI software. We hypothesized that ER proteins with hydrophilic residues might play a critical role in promoting flip-flop. Here, we evaluated the flip rate of fluorescently labeled lipids in vesicles containing each of the 11 synthetic peptides of membrane-spanning sequences, using a dithionite-quenching assay. Although the flippase activities of nine peptides were unexpectedly low, the peptides based on the EDEM1 and SPAST proteins showed enhanced flippase activity with three different fluorescently labeled lipids. The substitution of hydrophobic Ala with His or Arg in the central region of the EDEM1 or SPAST peptides, respectively, attenuated their ability to flip phospholipids. Interestingly, substituting Ala with Arg or His at a location outside of the central region of EDEM1 or SPAST, respectively, also affected the enhancement of flip-flop. These results indicated that both Arg and His are important for the ability of these two peptides to increase the flip rates. The EDEM1 peptide exhibited high activity at significantly low peptide concentrations, suggesting that the same side positioning of Arg and His in α-helix structure is critical for the flip-flop promotion and that the EDEM1 protein is a candidate flippase in the ER.
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Affiliation(s)
- Hiroyuki Nakao
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Keisuke Ikeda
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Yasushi Ishihama
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Minoru Nakano
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
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Luo J, Jiang L, Yang H, Song BL. Routes and mechanisms of post-endosomal cholesterol trafficking: A story that never ends. Traffic 2017; 18:209-217. [DOI: 10.1111/tra.12471] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/08/2017] [Accepted: 02/08/2017] [Indexed: 12/22/2022]
Affiliation(s)
- Jie Luo
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences; Wuhan University; Wuhan China
| | - Luyi Jiang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences; Wuhan University; Wuhan China
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences; The University of New South Wales; Sydney Australia
| | - Bao-Liang Song
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences; Wuhan University; Wuhan China
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28
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Lipid transfer proteins and the tuning of compartmental identity in the Golgi apparatus. Chem Phys Lipids 2016; 200:42-61. [DOI: 10.1016/j.chemphyslip.2016.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 06/21/2016] [Accepted: 06/22/2016] [Indexed: 11/23/2022]
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29
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Wang S, Zhai Y, Pang X, Niu T, Ding YH, Dong MQ, Hsu VW, Sun Z, Sun F. Structural characterization of coatomer in its cytosolic state. Protein Cell 2016; 7:586-600. [PMID: 27472951 PMCID: PMC4980336 DOI: 10.1007/s13238-016-0296-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 06/23/2016] [Indexed: 01/27/2023] Open
Abstract
Studies on coat protein I (COPI) have contributed to a basic understanding of how coat proteins generate vesicles to initiate intracellular transport. The core component of the COPI complex is coatomer, which is a multimeric complex that needs to be recruited from the cytosol to membrane in order to function in membrane bending and cargo sorting. Previous structural studies on the clathrin adaptors have found that membrane recruitment induces a large conformational change in promoting their role in cargo sorting. Here, pursuing negative-stain electron microscopy coupled with single-particle analyses, and also performing CXMS (chemical cross-linking coupled with mass spectrometry) for validation, we have reconstructed the structure of coatomer in its soluble form. When compared to the previously elucidated structure of coatomer in its membrane-bound form we do not observe a large conformational change. Thus, the result uncovers a key difference between how COPI versus clathrin coats are regulated by membrane recruitment.
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Affiliation(s)
- Shengliu Wang
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yujia Zhai
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaoyun Pang
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Tongxin Niu
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yue-He Ding
- National Institute of Biological Sciences, Beijing, Beijing, 102206, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, Beijing, 102206, China
| | - Victor W Hsu
- Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, 02115, USA
| | - Zhe Sun
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Fei Sun
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. .,Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
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30
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Truchan HK, VieBrock L, Cockburn CL, Ojogun N, Griffin BP, Wijesinghe DS, Chalfant CE, Carlyon JA. Anaplasma phagocytophilum Rab10-dependent parasitism of the trans-Golgi network is critical for completion of the infection cycle. Cell Microbiol 2016; 18:260-81. [PMID: 26289115 PMCID: PMC4891814 DOI: 10.1111/cmi.12500] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 08/03/2015] [Accepted: 08/18/2015] [Indexed: 02/01/2023]
Abstract
Anaplasma phagocytophilum is an emerging human pathogen and obligate intracellular bacterium. It inhabits a host cell-derived vacuole and cycles between replicative reticulate cell (RC) and infectious dense-cored (DC) morphotypes. Host-pathogen interactions that are critical for RC-to-DC conversion are undefined. We previously reported that A. phagocytophilum recruits green fluorescent protein (GFP)-tagged Rab10, a GTPase that directs exocytic traffic from the sphingolipid-rich trans-Golgi network (TGN) to its vacuole in a guanine nucleotide-independent manner. Here, we demonstrate that endogenous Rab10-positive TGN vesicles are not only routed to but also delivered into the A. phagocytophilum-occupied vacuole (ApV). Consistent with this finding, A. phagocytophilum incorporates sphingolipids while intracellular and retains them when naturally released from host cells. TGN vesicle delivery into the ApV is Rab10 dependent, up-regulates expression of the DC-specific marker, APH1235, and is critical for the production of infectious progeny. The A. phagocytophilum surface protein, uridine monophosphate kinase, was identified as a guanine nucleotide-independent, Rab10-specific ligand. These data delineate why Rab10 is important for the A. phagocytophilum infection cycle and expand the understanding of the benefits that exploiting host cell membrane traffic affords intracellular bacterial pathogens.
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Affiliation(s)
- Hilary K. Truchan
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Lauren VieBrock
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Chelsea L. Cockburn
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Nore Ojogun
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Brian P. Griffin
- Molecular Biology and Genetics Program, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Dayanjan S. Wijesinghe
- Department of Surgery, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Charles E. Chalfant
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
- Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
- The Victoria Johnson Center, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
- Institute for Molecular Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
- Research and Development, Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, VA, USA
| | - Jason A. Carlyon
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
- Molecular Biology and Genetics Program, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
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31
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Guo D, Bell EH, Mischel P, Chakravarti A. Targeting SREBP-1-driven lipid metabolism to treat cancer. Curr Pharm Des 2015; 20:2619-26. [PMID: 23859617 DOI: 10.2174/13816128113199990486] [Citation(s) in RCA: 213] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 06/24/2013] [Indexed: 01/17/2023]
Abstract
Metabolic reprogramming is a hallmark of cancer. Oncogenic growth signaling regulates glucose, glutamine and lipid metabolism to meet the bioenergetics and biosynthetic demands of rapidly proliferating tumor cells. Emerging evidence indicates that sterol regulatory element-binding protein 1 (SREBP-1), a master transcription factor that controls lipid metabolism, is a critical link between oncogenic signaling and tumor metabolism. We recently demonstrated that SREBP-1 is required for the survival of mutant EGFR-containing glioblastoma, and that this pro-survival metabolic pathway is mediated, in part, by SREBP-1-dependent upregulation of the fatty acid synthesis and low density lipoprotein (LDL) receptor (LDLR). These results have identified EGFR/PI3K/Akt/SREBP-1 signaling pathway that promotes growth and survival in glioblastoma, and potentially other cancer types. Here, we summarize recent insights in the understanding of cancer lipid metabolism, and discuss the evidence linking SREBP-1 with PI3K/Akt signaling-controlled glycolysis and with Myc-regulated glutaminolysis to lipid metabolism. We also discuss the development of potential drugs targeting the SREBP-1- driven lipid metabolism as anti-cancer agents.
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Affiliation(s)
| | | | | | - Arnab Chakravarti
- Department of Radiation Oncology, Ohio State University Comprehensive Cancer Center and Arthur G. James Cancer Hospital, Columbus, OH 43210, USA.
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32
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Bonaventura G, Barcellona ML, Golfetto O, Nourse JL, Flanagan LA, Gratton E. Laurdan monitors different lipids content in eukaryotic membrane during embryonic neural development. Cell Biochem Biophys 2014; 70:785-94. [PMID: 24839062 PMCID: PMC4228983 DOI: 10.1007/s12013-014-9982-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We describe a method based on fluorescence-lifetime imaging microscopy (FLIM) to assess the fluidity of various membranes in neuronal cells at different stages of development [day 12 (E12) and day 16 (E16) of gestation]. For the FLIM measurements, we use the Laurdan probe which is commonly used to assess membrane water penetration in model and in biological membranes using spectral information. Using the FLIM approach, we build a fluidity scale based on calibration with model systems of different lipid compositions. In neuronal cells, we found a marked difference in fluidity between the internal membranes and the plasma membrane, being the plasma membrane the less fluid. However, we found no significant differences between the two cell groups, E12 and E16. Comparison with NIH3T3 cells shows that the plasma membranes of E12 and E16 cells are significantly more fluid than the plasma membrane of the cancer cells.
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Affiliation(s)
- Gabriele Bonaventura
- Department of Drug Science, Section of Biochemistry, University of Catania, Catania, Italy,
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33
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Mijajlovic M, Wright D, Zivkovic V, Bi J, Biggs M. Microfluidic hydrodynamic focusing based synthesis of POPC liposomes for model biological systems. Colloids Surf B Biointerfaces 2013; 104:276-81. [DOI: 10.1016/j.colsurfb.2012.12.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 12/09/2012] [Accepted: 12/10/2012] [Indexed: 10/27/2022]
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Jennemann R, Gröne HJ. Cell-specific in vivo functions of glycosphingolipids: lessons from genetic deletions of enzymes involved in glycosphingolipid synthesis. Prog Lipid Res 2013; 52:231-48. [PMID: 23473748 DOI: 10.1016/j.plipres.2013.02.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 02/20/2013] [Accepted: 02/25/2013] [Indexed: 11/16/2022]
Abstract
Glycosphingolipids (GSLs) are believed to be involved in many cellular events including trafficking, signaling and cellular interactions. Over the past decade considerable progress was made elucidating the function of GSLs by generating and exploring animal models with GSL-deficiency. Initial studies focused on exploring the role of complex sialic acid containing GSLs (gangliosides) in neuronal tissue. Although complex gangliosides were absent, surprisingly, the phenotype observed was rather mild. In subsequent studies, several mouse models with combinations of gene-deletions encoding GSL-synthesizing enzymes were developed. The results indicated that reduction of GSL-complexity correlated with severity of phenotypes. However, in these mice, accumulation of precursor GSLs or neobiosynthesized GSL-series seemed to partly compensate the loss of GSLs. Thus, UDP-glucose:ceramide glucosyltransferase (Ugcg), catalyzing the basic step of the glucosylceramide-based GSL-biosynthesis, was genetically disrupted. A total systemic deletion of Ugcg caused early embryonic lethality. Therefore, Ugcg was eliminated in a cell-specific manner using the cre/loxP-system. New insights into the cellular function of GSLs were gained. It was demonstrated that neurons require GSLs for differentiation and maintenance. In keratinocytes, preservation of the skin barrier depends on GSL synthesis and in enterocytes of the small intestine GSLs are involved in endocytosis and vesicular transport.
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Affiliation(s)
- Richard Jennemann
- Department of Cellular and Molecular Pathology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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35
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Abstract
The Golgi complex is considered the central station of the secretory pathway where cargo proteins and lipids are properly modified, classified, packed into specific carriers and delivered to their final destinations. Early electron microscope studies showed the extraordinary structural complexity of this organelle. However, despite the large volume of incoming and outgoing traffic, it is able to maintain its architecture, although it is also flexible enough to adapt to the functional status of the cell. Many components of the molecular machinery involved in membrane traffic and other Golgi functions have been identified. However, some basic aspects of Golgi functioning remain unsolved. For instance, how cargo moves through the stack remains controversial and two classical models have been proposed: vesicular transport and cisternal maturation. Since neither of these models explains all the experimental data, a combination of these models as well as new models have been proposed. In this context, the specific role of the cisternae, vesicles and tubules needs to be clarified. In this review, we summarize our current knowledge of the Golgi organization and function, focusing on the mechanisms of intra-Golgi transport.
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36
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Lorizate M, Sachsenheimer T, Glass B, Habermann A, Gerl MJ, Kräusslich HG, Brügger B. Comparative lipidomics analysis of HIV-1 particles and their producer cell membrane in different cell lines. Cell Microbiol 2013; 15:292-304. [DOI: 10.1111/cmi.12101] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 11/27/2012] [Accepted: 12/17/2012] [Indexed: 12/13/2022]
Affiliation(s)
- Maier Lorizate
- Department of Infectious Diseases; Virology; University of Heidelberg; 69120; Heidelberg; Germany
| | - Timo Sachsenheimer
- Heidelberg University Biochemistry Center; Im Neuenheimer Feld 328; 69120; Heidelberg; Germany
| | - Bärbel Glass
- Department of Infectious Diseases; Virology; University of Heidelberg; 69120; Heidelberg; Germany
| | - Anja Habermann
- Department of Infectious Diseases; Virology; University of Heidelberg; 69120; Heidelberg; Germany
| | - Mathias J. Gerl
- Heidelberg University Biochemistry Center; Im Neuenheimer Feld 328; 69120; Heidelberg; Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases; Virology; University of Heidelberg; 69120; Heidelberg; Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center; Im Neuenheimer Feld 328; 69120; Heidelberg; Germany
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Larijani B, Poccia DL. Effects of Phosphoinositides and Their Derivatives on Membrane Morphology and Function. Curr Top Microbiol Immunol 2012; 362:99-110. [DOI: 10.1007/978-94-007-5025-8_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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38
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Cellular Mechanisms for the Biogenesis and Transport of Synaptic and Dense-Core Vesicles. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 299:27-115. [DOI: 10.1016/b978-0-12-394310-1.00002-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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39
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Invertebrate models of lysosomal storage disease: what have we learned so far? INVERTEBRATE NEUROSCIENCE 2011; 11:59-71. [PMID: 22038288 DOI: 10.1007/s10158-011-0125-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 10/08/2011] [Indexed: 01/17/2023]
Abstract
The lysosomal storage diseases (LSDs) collectively account for death in 1 in 8,000 children. Although some forms are treatable, they are essentially incurable and usually are lethal in the first decade of life. The most intractable forms of LSD are those with neuronal involvement. In an effort to identify the pathological signaling driving pathology in the LSDs, invertebrate models have been developed. In this review, we outline our current understanding of LSDs and recent findings using invertebrate models. We outline strategies and pitfalls for the development of such models. Available models of LSD in Drosophila and Caenorhabditis elegans are uncovering roles for LSD-related proteins with previously unknown function using both gain-of-function and loss-of-function strategies. These models of LSD in Drosophila and C. elegans have identified potential pathogenic signaling cascades that are proving critical to our understanding of these lethal diseases.
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40
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Fairn GD, Schieber NL, Ariotti N, Murphy S, Kuerschner L, Webb RI, Grinstein S, Parton RG. High-resolution mapping reveals topologically distinct cellular pools of phosphatidylserine. ACTA ACUST UNITED AC 2011; 194:257-75. [PMID: 21788369 PMCID: PMC3144401 DOI: 10.1083/jcb.201012028] [Citation(s) in RCA: 223] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Phosphatidylserine exists lumenally in the ER, Golgi, and mitochondria but cytoplasmically in the trans-Golgi and at the plasma membrane, which suggests that functionally important flipping may occur during trafficking. Phosphatidylserine (PS) plays a central role in cell signaling and in the biosynthesis of other lipids. To date, however, the subcellular distribution and transmembrane topology of this crucial phospholipid remain ill-defined. We transfected cells with a GFP-tagged C2 domain of lactadherin to detect by light and electron microscopy PS exposed on the cytosolic leaflet of the plasmalemma and organellar membranes. Cytoplasmically exposed PS was found to be clustered on the plasma membrane, and to be associated with caveolae, the trans-Golgi network, and endocytic organelles including intraluminal vesicles of multivesicular endosomes. This labeling pattern was compared with the total cellular distribution of PS as visualized using a novel on-section technique. These complementary methods revealed PS in the interior of the ER, Golgi complex, and mitochondria. These results indicate that PS in the lumenal monolayer of the ER and Golgi complex becomes exposed cytosolically at the trans-Golgi network. Transmembrane flipping of PS may contribute to the exit of cargo from the Golgi complex.
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Affiliation(s)
- Gregory D Fairn
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
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41
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Holdbrook DA, Leung YM, Piggot TJ, Marius P, Williamson PTF, Khalid S. Stability and membrane orientation of the fukutin transmembrane domain: a combined multiscale molecular dynamics and circular dichroism study. Biochemistry 2010; 49:10796-802. [PMID: 21105749 PMCID: PMC3005826 DOI: 10.1021/bi101743w] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
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The N-terminal domain of fukutin-I has been implicated in the localization of the protein in the endoplasmic reticulum and Golgi Apparatus. It has been proposed to mediate this through its interaction with the thinner lipid bilayers found in these compartments. Here we have employed multiscale molecular dynamics simulations and circular dichroism spectroscopy to explore the structure, stability, and orientation of the short 36-residue N-terminus of fukutin-I (FK1TMD) in lipids with differing tail lengths. Our results show that FK1TMD adopts a stable helical conformation in phosphatidylcholine lipids when oriented with its principal axis perpendicular to the bilayer plane. The stability of the helix is largely insensitive to the lipid tail length, preventing hydrophobic mismatch by virtue of its mobility and ability to tilt within the lipid bilayers. This suggests that changes in FK1TMD tilt in response to bilayer properties may be implicated in the regulation of its trafficking. Coarse-grained simulations of the complex Golgi membrane suggest the N-terminal domain may induce the formation of microdomains in the surrounding membrane through its preferential interaction with 1,2-dipalmitoyl-sn-glycero-3-phosphatidylinositol 4,5-bisphosphate lipids.
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Affiliation(s)
- Daniel A Holdbrook
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
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Kunkel MT, Newton AC. Calcium transduces plasma membrane receptor signals to produce diacylglycerol at Golgi membranes. J Biol Chem 2010; 285:22748-52. [PMID: 20519514 DOI: 10.1074/jbc.c110.123133] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein kinase C and protein kinase D are potently activated by agonist-evoked increases in diacylglycerol. Using live cell-imaging probes for kinase activity, we have shown that both kinases are robustly activated at the Golgi following stimulation of G(q)-coupled receptor signaling pathways, displaying activation signatures at the Golgi that are distinct from those at the plasma membrane. Here we report that Ca(2+) is the mediator that allows signals received at the plasma membrane to activate these two protein kinases at the Golgi. Specifically, using fluorescence resonance energy transfer-based reporters to image diacylglycerol production, we show that Ca(2+) is necessary and sufficient to elevate diacylglycerol levels at the Golgi. First, raising intracellular Ca(2+) by treating cells with thapsigargin induces diacylglycerol production at the Golgi. Second, chelation of intracellular Ca(2+) prevents UTP-stimulated increases in diacylglycerol at the Golgi. Thus, agonist-evoked increases in intracellular Ca(2+) cause increases in Golgi diacylglycerol, allowing this intracellular membrane to serve as a platform for signaling by protein kinases C and D.
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Affiliation(s)
- Maya T Kunkel
- Department of Pharmacology, University of California at San Diego, La Jolla, California 92093, USA
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Abstract
Retroviruses undergo several critical steps to complete a replication cycle. These include the complex processes of virus entry, assembly, and budding that often take place at the plasma membrane of the host cell. Both virus entry and release involve membrane fusion/fission reactions between the viral envelopes and host cell membranes. Accumulating evidence indicates important roles for lipids and lipid microdomains in virus entry and egress. In this review, we outline the current understanding of the role of lipids and membrane microdomains in retroviral replication.
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Fischer MA, Temmerman K, Ercan E, Nickel W, Seedorf M. Binding of Plasma Membrane Lipids Recruits the Yeast Integral Membrane Protein Ist2 to the Cortical ER. Traffic 2009; 10:1084-97. [PMID: 19453974 DOI: 10.1111/j.1600-0854.2009.00926.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Marcel André Fischer
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
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Singh H, Ashley RH. CLIC4 (p64H1) and its putative transmembrane domain form poorly selective, redox-regulated ion channels. Mol Membr Biol 2009; 24:41-52. [PMID: 17453412 DOI: 10.1080/09687860600927907] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Despite being synthesized in the cytosol without a leader sequence, the soluble 253-residue mammalian protein CLIC4 (Chloride Intracellular Channel 4, or p64H1), a structural homologue of Omega-type glutathione-S-transferase, autoinserts into membranes to form an integral membrane protein with ion channel activity. A predicted transmembrane domain (TMD) near the N-terminus of CLIC4 could mediate membrane insertion, and contribute to oligomeric pores, with minimal reorganization of the soluble protein structure. We tested this idea by reconstituting recombinant CLIC4 in planar bilayers containing phosphatidyethanolamine, phosphatidylserine and cholesterol, recording ion channels with a maximum conductance of approximately 15 pS in KCl under both oxidizing and reducing conditions. The channels discriminated poorly between anions and cations, incompatible with the current "CLIC" nomenclature, and their conductance was modified by the trans (external or luminal) redox potential, as previously observed for CLIC1. We then reconstituted a truncated version of the protein, limited to the first 61 residues containing the predicted TMD. This included a single trans cysteine residue in the putative pore-forming subunits, at the external entrance to the pore. The truncated protein formed non-selective channels with a reduced conductance, but they retained their trans-redox sensitivity, and could still be blocked or inactivated by trans (not cis) thiol-reative dithiobisnitrobenzoic acid. We suggest that oligomers containing the putative TMD are essential components of the CLIC4 pore. However, the pore is inherently non-selective, and any ionic selectivity in CLIC4 (and other membrane CLICs) may be attributable to other regions of the protein, including the channel vestibules.
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Affiliation(s)
- Harpreet Singh
- Biomedical Sciences, College of Medicine, University of Edinburgh, Edinburgh, UK
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Holthuis JCM, van Meer G, Huitema K. Lipid microdomains, lipid translocation and the organization of intracellular membrane transport (Review). Mol Membr Biol 2009. [DOI: 10.1080/0988768031000100768] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Goldfinger M, Laviad EL, Hadar R, Shmuel M, Dagan A, Park H, Merrill AH, Ringel I, Futerman AH, Tirosh B. De novo ceramide synthesis is required for N-linked glycosylation in plasma cells. THE JOURNAL OF IMMUNOLOGY 2009; 182:7038-47. [PMID: 19454701 DOI: 10.4049/jimmunol.0802990] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Plasma cells (PCs) are terminally differentiated B lymphocytes responsible for the synthesis and secretion of Igs. The differentiation of B cells into PCs involves a remarkable expansion of both lipid and protein components of the endoplasmic reticulum. Despite their importance in many signal transduction pathways, the role of ceramides, and of complex sphingolipids that are derived from ceramide, in PC differentiation has never been directly studied. To assess their putative role in PC differentiation, we blocked ceramide synthesis with fumonisin B1, a specific inhibitor of ceramide synthase. Under fumonisin B1 treatment, N-linked glycosylation was severely impaired in LPS-activated, but not in naive, B cells. We also show that ceramide synthesis is strongly induced by XBP-1 (X box-binding protein-1). In the absence of ceramide synthesis, ER expansion was dramatically diminished. Our results underscore ceramide biosynthesis as a key metabolic pathway in the process of PC differentiation and reveal a previously unknown functional link between sphingolipids and N-linked glycosylation in PCs.
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Affiliation(s)
- Meidan Goldfinger
- Department of Pharmacology and Experimental Therapeutics, School of Pharmacy, The Hebrew University, Jerusalem, Israel
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Kooijman EE, Vaknin D, Bu W, Joshi L, Kang SW, Gericke A, Mann EK, Kumar S. Structure of ceramide-1-phosphate at the air-water solution interface in the absence and presence of Ca2+. Biophys J 2009; 96:2204-15. [PMID: 19289047 DOI: 10.1016/j.bpj.2008.11.062] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 10/27/2008] [Accepted: 11/18/2008] [Indexed: 01/20/2023] Open
Abstract
Ceramide-1-phosphate, the phosphorylated form of ceramide, gained attention recently due to its diverse intracellular roles, in particular in inflammation mediated by cPLA(2)alpha. However, surprisingly little is known about the physical chemical properties of this lipid and its potential impact on physiological function. For example, the presence of Ca(2+) is indispensable for the interaction of Cer-1-P with the C2 domain of cPLA(2)alpha. We report on the structure and morphology of Cer-1-P in monomolecular layers at the air/water solution interface in the absence and presence of Ca(2+) using diverse biophysical techniques, including synchrotron x-ray reflectivity and grazing angle diffraction, to gain insight into the role and function of Cer-1-P in biomembranes. We show that relatively small changes in pH and the presence of monovalent cations dramatically affect the behavior of Cer-1-P. On pure water Cer-1-P forms a solid monolayer despite the negative charge of the phosphomonoester headgroup. In contrast, pH 7.2 buffer yields a considerably less solid-like monolayer, indicating that charge-charge repulsion becomes important at higher pH. Calcium was found to bind strongly to the headgroup of Cer-1-P even in the presence of a 100-fold larger Na(+) concentration. Analysis of the x-ray reflectivity data allowed us to estimate how much Ca(2+) is bound to the headgroup, approximately 0.5 Ca(2+) and approximately 1.0 Ca(2+) ions per Cer-1-P molecule for the water and buffer subphase respectively. These results can be qualitatively understood based on the molecular structure of Cer-1-P and the electrostatic/hydrogen-bond interactions of its phosphomonoester headgroup. Biological implications of our results are also discussed.
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Affiliation(s)
- Edgar E Kooijman
- Department of Biological Sciences, Kent State University, Kent, Ohio 44242
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