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Vela-Corcia D, Hierrezuelo J, Pérez-Lorente AI, Stincone P, Pakkir Shah AK, Grélard A, Zi-Long Y, de Vicente A, Pérez García A, Bai L, Loquet A, Petras D, Romero D. Cyclo(Pro-Tyr) elicits conserved cellular damage in fungi by targeting the [H +]ATPase Pma1 in plasma membrane domains. Commun Biol 2024; 7:1253. [PMID: 39362977 PMCID: PMC11449911 DOI: 10.1038/s42003-024-06947-3] [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: 01/26/2024] [Accepted: 09/24/2024] [Indexed: 10/05/2024] Open
Abstract
Bioactive metabolites play a crucial role in shaping interactions among diverse organisms. In this study, we identified cyclo(Pro-Tyr), a metabolite produced by Bacillus velezensis, as a potent inhibitor of Botrytis cinerea and Caenorhabditis elegans, two potential cohabitant eukaryotic organisms. Based on our investigation, cyclo(Pro-Tyr) disrupts plasma membrane polarization, induces oxidative stress and increases membrane fluidity, which compromises fungal membrane integrity. These cytological and physiological changes induced by cyclo(Pro-Tyr) may be triggered by the destabilization of membrane microdomains containing the [H+]ATPase Pma1. In response to cyclo(Pro-Tyr) stress, fungal cells activate a transcriptomic and metabolomic response, which primarily involves lipid metabolism and Reactive Oxygen Species (ROS) detoxification, to mitigate membrane damage. This similar response occurs in the nematode C. elegans, indicating that cyclo(Pro-Tyr) targets eukaryotic cellular membranes.
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Affiliation(s)
- D Vela-Corcia
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - J Hierrezuelo
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - A I Pérez-Lorente
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - P Stincone
- University of Tuebingen, CMFI Cluster of Excellence, Interfaculty Institute of Microbiology and Infection Medicine, Tuebingen, Germany
- University of Tuebingen, Center for Plant Molecular Biology, Tuebingen, Germany
| | - A K Pakkir Shah
- University of Tuebingen, CMFI Cluster of Excellence, Interfaculty Institute of Microbiology and Infection Medicine, Tuebingen, Germany
| | - A Grélard
- L'Institut de Chimie et Biologie des Membranes et des Nano-Objets (CBMN), Unité Mixte de Recherche (UMR) 5248, Centre National de la Recherche (CNRS), University of Bordeaux, Pessac, France
| | - Y Zi-Long
- Department of Biophysics, School of Basic Medical Sciences, Peking University, Beijing, China
| | - A de Vicente
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - A Pérez García
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - L Bai
- Department of Biophysics, School of Basic Medical Sciences, Peking University, Beijing, China
| | - A Loquet
- L'Institut de Chimie et Biologie des Membranes et des Nano-Objets (CBMN), Unité Mixte de Recherche (UMR) 5248, Centre National de la Recherche (CNRS), University of Bordeaux, Pessac, France
| | - D Petras
- University of Tuebingen, CMFI Cluster of Excellence, Interfaculty Institute of Microbiology and Infection Medicine, Tuebingen, Germany
- University of California Riverside, Department of Biochemistry, Riverside, USA
| | - D Romero
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Málaga, Spain.
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2
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Hoh KL, Mu B, See T, Ng AYE, Ng AQE, Zhang D. VAP-mediated membrane-tethering mechanisms implicate ER-PM contact function in pH homeostasis. Cell Rep 2024; 43:114592. [PMID: 39110593 DOI: 10.1016/j.celrep.2024.114592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/03/2024] [Accepted: 07/22/2024] [Indexed: 09/01/2024] Open
Abstract
Vesicle-associated membrane protein (VAMP)-associated proteins (VAPs) are highly conserved endoplasmic reticulum (ER)-resident proteins that establish ER contacts with multiple membrane compartments in many eukaryotes. However, VAP-mediated membrane-tethering mechanisms remain ambiguous. Here, focusing on fission yeast ER-plasma membrane (PM) contact formation, using systematic interactome analyses and quantitative microscopy, we predict a non-VAP-protein direct binding-based ER-PM coupling. We further reveal that VAP-anionic phospholipid interactions may underlie ER-PM association and define the pH-responsive nature of VAP-tethered membrane contacts. Such conserved interactions with anionic phospholipids are generally defective in amyotrophic lateral sclerosis-associated human VAPB mutant. Moreover, we identify a conserved FFAT-like motif locating at the autoinhibitory hotspot of the essential PM proton pump Pma1. This modulatory VAP-Pma1 interaction appears crucial for pH homeostasis. We thus propose an ingenious strategy for maintaining intracellular pH by coupling Pma1 modulation with pH-sensory ER-PM contacts via VAP-mediated interactions.
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Affiliation(s)
- Kar Ling Hoh
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Baicong Mu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Tingyi See
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - Amanda Yunn Ee Ng
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Annabel Qi En Ng
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - Dan Zhang
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore.
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3
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Brown CM, Marrink SJ. Modeling membranes in situ. Curr Opin Struct Biol 2024; 87:102837. [PMID: 38744147 DOI: 10.1016/j.sbi.2024.102837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/26/2024] [Accepted: 04/23/2024] [Indexed: 05/16/2024]
Abstract
Molecular dynamics simulations of cellular membranes have come a long way-from simple model lipid bilayers to multicomponent systems capturing the crowded and complex nature of real cell membranes. In this opinionated minireview, we discuss the current challenge to simulate the dynamics of membranes in their native environment, in situ, with the prospect of reaching the level of whole cells and cell organelles using an integrative modeling framework.
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Affiliation(s)
- Chelsea M Brown
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands. https://twitter.com/chelseabrowncg
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands. s.j.marrinkrug.nl
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4
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Jiang J, Keniya MV, Puri A, Zhan X, Cheng J, Wang H, Lin G, Lee YK, Jaber N, Hassoun Y, Shor E, Shi Z, Lee SH, Xu M, Perlin DS, Dai W. Structural and Biophysical Dynamics of Fungal Plasma Membrane Proteins and Implications for Echinocandin Action in Candida glabrata. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.596243. [PMID: 38854035 PMCID: PMC11160696 DOI: 10.1101/2024.05.29.596243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Fungal plasma membrane proteins represent key therapeutic targets for antifungal agents, yet their structure and spatial distribution in the native context remain poorly characterized. Herein, we employ an integrative multimodal approach to elucidate the structural and functional organization of plasma membrane protein complexes in Candida glabrata , focusing on prominent and essential membrane proteins, the polysaccharide synthase β-(1,3)-glucan synthase (GS) and the proton pump Pma1. Cryo-electron tomography (cryo-ET) and live cell imaging reveal that GS and Pma1 are heterogeneously distributed into distinct plasma membrane microdomains. Treatment with caspofungin, an echinocandin antifungal that targets GS, alters the plasma membrane and disrupts the native distribution of GS and Pma1. Based on these findings, we propose a model for echinocandin action that considers how drug interactions with the plasma membrane environment lead to inhibition of GS. Our work underscores the importance of interrogating the structural and dynamic characteristics of fungal plasma membrane proteins in situ to understand function and facilitate precisely targeted development of novel antifungal therapies.
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5
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Zhao CR, You ZL, Bai L. Fungal Plasma Membrane H +-ATPase: Structure, Mechanism, and Drug Discovery. J Fungi (Basel) 2024; 10:273. [PMID: 38667944 PMCID: PMC11051447 DOI: 10.3390/jof10040273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 04/28/2024] Open
Abstract
The fungal plasma membrane H+-ATPase (Pma1) pumps protons out of the cell to maintain the transmembrane electrochemical gradient and membrane potential. As an essential P-type ATPase uniquely found in fungi and plants, Pma1 is an attractive antifungal drug target. Two recent Cryo-EM studies on Pma1 have revealed its hexameric architecture, autoinhibitory and activation mechanisms, and proton transport mechanism. These structures provide new perspectives for the development of antifungal drugs targeting Pma1. In this article, we review the history of Pma1 structure determination, the latest structural insights into Pma1, and drug discoveries targeting Pma1.
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Affiliation(s)
- Chao-Ran Zhao
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
- Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing 100005, China
| | - Zi-Long You
- Department of Biophysics, School of Basic Medical Sciences, Peking University, Beijing 100083, China
| | - Lin Bai
- Department of Biophysics, School of Basic Medical Sciences, Peking University, Beijing 100083, China
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6
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Vishnu N, Venkatesan M, Madaris TR, Venkateswaran MK, Stanley K, Ramachandran K, Chidambaram A, Madesh AK, Yang W, Nair J, Narkunan M, Muthukumar T, Karanam V, Joseph LC, Le A, Osidele A, Aslam MI, Morrow JP, Malicdan MC, Stathopulos PB, Madesh M. ERMA (TMEM94) is a P-type ATPase transporter for Mg 2+ uptake in the endoplasmic reticulum. Mol Cell 2024; 84:1321-1337.e11. [PMID: 38513662 PMCID: PMC10997467 DOI: 10.1016/j.molcel.2024.02.033] [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: 04/22/2023] [Revised: 10/16/2023] [Accepted: 02/27/2024] [Indexed: 03/23/2024]
Abstract
Intracellular Mg2+ (iMg2+) is bound with phosphometabolites, nucleic acids, and proteins in eukaryotes. Little is known about the intracellular compartmentalization and molecular details of Mg2+ transport into/from cellular organelles such as the endoplasmic reticulum (ER). We found that the ER is a major iMg2+ compartment refilled by a largely uncharacterized ER-localized protein, TMEM94. Conventional and AlphaFold2 predictions suggest that ERMA (TMEM94) is a multi-pass transmembrane protein with large cytosolic headpiece actuator, nucleotide, and phosphorylation domains, analogous to P-type ATPases. However, ERMA uniquely combines a P-type ATPase domain and a GMN motif for ERMg2+ uptake. Experiments reveal that a tyrosine residue is crucial for Mg2+ binding and activity in a mechanism conserved in both prokaryotic (mgtB and mgtA) and eukaryotic Mg2+ ATPases. Cardiac dysfunction by haploinsufficiency, abnormal Ca2+ cycling in mouse Erma+/- cardiomyocytes, and ERMA mRNA silencing in human iPSC-cardiomyocytes collectively define ERMA as an essential component of ERMg2+ uptake in eukaryotes.
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Affiliation(s)
- Neelanjan Vishnu
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Manigandan Venkatesan
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Travis R Madaris
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Mridula K Venkateswaran
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Kristen Stanley
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Karthik Ramachandran
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Adhishree Chidambaram
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Abitha K Madesh
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Wenli Yang
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jyotsna Nair
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Melanie Narkunan
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Tharani Muthukumar
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Varsha Karanam
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Leroy C Joseph
- Department of Medicine, College of Physicians and Surgeons of Columbia University, 650 W 168 Street, New York, NY 10032, USA
| | - Amy Le
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - Ayodeji Osidele
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - M Imran Aslam
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
| | - John P Morrow
- Department of Medicine, College of Physicians and Surgeons of Columbia University, 650 W 168 Street, New York, NY 10032, USA
| | - May C Malicdan
- Section of Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA; NIH Undiagnosed Diseases Program, Office of the Clinical Director, National Human Genome Research Institute, and the Common Fund, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Western University, London, ON N6A 5C1, Canada
| | - Muniswamy Madesh
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA; Center for Mitochondrial Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA.
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7
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Jiménez-Ortigosa C, Jiang J, Chen M, Kuang X, Healey KR, Castellano P, Boparai N, Ludtke SJ, Perlin DS, Dai W. Correction: Jiménez-Ortigosa et al. Cryo-Electron Tomography of Candida glabrata Plasma Membrane Proteins. J. Fungi 2021, 7, 120. J Fungi (Basel) 2024; 10:201. [PMID: 38535242 PMCID: PMC10971649 DOI: 10.3390/jof10030201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 11/15/2023] [Indexed: 04/12/2024] Open
Abstract
The authors wish to update the article title to "Cryo-Electron Tomography of Candida glabrata Plasma Membrane Proteins" [...].
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Affiliation(s)
- Cristina Jiménez-Ortigosa
- Hackensack Meridian Health-Center for Discovery and Innovation, 111 Ideation Way, Nutley, NJ 07110, USA;
| | - Jennifer Jiang
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Muyuan Chen
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA; (M.C.); (S.J.L.)
| | - Xuyuan Kuang
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
- Department of Hyperbaric Oxygen, Central South University, Changsha 410008, China
| | - Kelley R. Healey
- Department of Biology, William Paterson University, 300 Pompton Road, Wayne, NJ 07470, USA;
| | - Paul Castellano
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Nikpreet Boparai
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Steven J. Ludtke
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA; (M.C.); (S.J.L.)
| | - David S. Perlin
- Hackensack Meridian Health-Center for Discovery and Innovation, 111 Ideation Way, Nutley, NJ 07110, USA;
| | - Wei Dai
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
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8
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Zeinert R, Zhou F, Franco P, Zöller J, Lessen HJ, Aravind L, Langer JD, Sodt AJ, Storz G, Matthies D. Magnesium Transporter MgtA revealed as a Dimeric P-type ATPase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582502. [PMID: 38464158 PMCID: PMC10925321 DOI: 10.1101/2024.02.28.582502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Magnesium (Mg2+) uptake systems are present in all domains of life given the vital role of this ion. Bacteria acquire Mg2+ via conserved Mg2+ channels and transporters. The transporters are required for growth when Mg2+ is limiting or during bacterial pathogenesis, but, despite their significance, there are no known structures for these transporters. Here we report the first structure of the Mg2+ transporter MgtA solved by single particle cryo-electron microscopy (cryo-EM). Using mild membrane extraction, we obtained high resolution structures of both a homodimeric form (2.9 Å), the first for a P-type ATPase, and a monomeric form (3.6 Å). Each monomer unit of MgtA displays a structural architecture that is similar to other P-type ATPases with a transmembrane domain and two soluble domains. The dimer interface consists of contacts between residues in adjacent soluble nucleotide binding and phosphotransfer regions of the haloacid dehalogenase (HAD) domain. We suggest oligomerization is a conserved structural feature of the diverse family of P-type ATPase transporters. The ATP binding site and conformational dynamics upon nucleotide binding to MgtA were characterized using a combination of cryo-EM, molecular dynamics simulations, hydrogen-deuterium exchange mass spectrometry, and mutagenesis. Our structure also revealed a Mg2+ ion in the transmembrane segments, which, when combined with sequence conservation and mutagenesis studies, allowed us to propose a model for Mg2+ transport across the lipid bilayer. Finally, our work revealed the N-terminal domain structure and cytoplasmic Mg2+ binding sites, which have implications for related P-type ATPases defective in human disease.
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Affiliation(s)
- Rilee Zeinert
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - Fei Zhou
- Unit on Structural Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - Pedro Franco
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Jonathan Zöller
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Henry J. Lessen
- Unit on Membrane Chemical Physics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - L. Aravind
- National Center for Biotechnology Information, National Institutes of Health, Bethesda MD 20892, USA
| | - Julian D. Langer
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Alexander J. Sodt
- Unit on Membrane Chemical Physics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
| | - Doreen Matthies
- Unit on Structural Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
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9
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Fuji S, Yamauchi S, Sugiyama N, Kohchi T, Nishihama R, Shimazaki KI, Takemiya A. Light-induced stomatal opening requires phosphorylation of the C-terminal autoinhibitory domain of plasma membrane H +-ATPase. Nat Commun 2024; 15:1195. [PMID: 38378726 PMCID: PMC10879506 DOI: 10.1038/s41467-024-45236-9] [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: 02/13/2023] [Accepted: 01/16/2024] [Indexed: 02/22/2024] Open
Abstract
Plasma membrane H+-ATPase provides the driving force for light-induced stomatal opening. However, the mechanisms underlying the regulation of its activity remain unclear. Here, we show that the phosphorylation of two Thr residues in the C-terminal autoinhibitory domain is crucial for H+-ATPase activation and stomatal opening in Arabidopsis thaliana. Using phosphoproteome analysis, we show that blue light induces the phosphorylation of Thr-881 within the C-terminal region I, in addition to penultimate Thr-948 in AUTOINHIBITED H+-ATPASE 1 (AHA1). Based on site-directed mutagenesis experiments, phosphorylation of both Thr residues is essential for H+ pumping and stomatal opening in response to blue light. Thr-948 phosphorylation is a prerequisite for Thr-881 phosphorylation by blue light. Additionally, red light-driven guard cell photosynthesis induces Thr-881 phosphorylation, possibly contributing to red light-dependent stomatal opening. Our findings provide mechanistic insights into H+-ATPase activation that exploits the ion transport across the plasma membrane and light signalling network in guard cells.
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Affiliation(s)
- Saashia Fuji
- Department of Biology, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8512, Japan
| | - Shota Yamauchi
- Department of Biology, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8512, Japan
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Chiba, Japan
| | - Naoyuki Sugiyama
- Department of Molecular & Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, 606-8501, Japan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Ryuichi Nishihama
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Ken-Ichiro Shimazaki
- Department of Biology, Faculty of Science, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan
| | - Atsushi Takemiya
- Department of Biology, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8512, Japan.
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10
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Guarini N, Saliba E, André B. Phosphoregulation of the yeast Pma1 H+-ATPase autoinhibitory domain involves the Ptk1/2 kinases and the Glc7 PP1 phosphatase and is under TORC1 control. PLoS Genet 2024; 20:e1011121. [PMID: 38227612 PMCID: PMC10817110 DOI: 10.1371/journal.pgen.1011121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 01/26/2024] [Accepted: 01/03/2024] [Indexed: 01/18/2024] Open
Abstract
Plasma membrane (PM) H+-ATPases of the P-type family are highly conserved in yeast, other fungi, and plants. Their main role is to establish an H+ gradient driving active transport of small ions and metabolites across the PM and providing the main component of the PM potential. Furthermore, in both yeast and plant cells, conditions have been described under which active H+-ATPases promote activation of TORC1, the rapamycin-sensitive kinase complex controlling cell growth. Fungal and plant PM H+-ATPases are self-inhibited by their respective cytosolic carboxyterminal tails unless this domain is phosphorylated at specific residues. In the yeast H+-ATPase Pma1, neutralization of this autoinhibitory domain depends mostly on phosphorylation of the adjacent Ser911 and Thr912 residues, but the kinase(s) and phosphatase(s) controlling this tandem phosphorylation remain unknown. In this study, we show that S911-T912 phosphorylation in Pma1 is mediated by the largely redundant Ptk1 and Ptk2 kinase paralogs. Dephosphorylation of S911-T912, as occurs under glucose starvation, is dependent on the Glc7 PP1 phosphatase. Furthermore, proper S911-T912 phosphorylation in Pma1 is required for optimal TORC1 activation upon H+ influx coupled amino-acid uptake. We finally show that TORC1 controls S911-T912 phosphorylation in a manner suggesting that activated TORC1 promotes feedback inhibition of Pma1. Our results shed important new light on phosphoregulation of the yeast Pma1 H+-ATPase and on its interconnections with TORC1.
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Affiliation(s)
- Nadia Guarini
- Molecular Physiology of the Cell, Université Libre de Bruxelles (ULB), Biopark, Gosselies, Belgium
| | - Elie Saliba
- Molecular Physiology of the Cell, Université Libre de Bruxelles (ULB), Biopark, Gosselies, Belgium
| | - Bruno André
- Molecular Physiology of the Cell, Université Libre de Bruxelles (ULB), Biopark, Gosselies, Belgium
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11
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Young MR, Heit S, Bublitz M. Structure, function and biogenesis of the fungal proton pump Pma1. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119600. [PMID: 37741574 DOI: 10.1016/j.bbamcr.2023.119600] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 08/19/2023] [Accepted: 09/18/2023] [Indexed: 09/25/2023]
Abstract
The fungal plasma membrane proton pump Pma1 is an integral plasma membrane protein of the P-type ATPase family. It is an essential enzyme responsible for maintaining a constant cytosolic pH and for energising the plasma membrane to secondary transport processes. Due to its importance for fungal survival and absence from animals, Pma1 is also a highly sought-after drug target. Until recently, its characterisation has been limited to functional, mutational and localisation studies, due to a lack of high-resolution structural information. The determination of three cryo-EM structures of Pma1 in its unique hexameric state offers a new level of understanding the molecular mechanisms underlying the protein's stability, regulated activity and druggability. In light of this context, this article aims to review what we currently know about the structure, function and biogenesis of fungal Pma1.
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Affiliation(s)
- Margaret R Young
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Sabine Heit
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Maike Bublitz
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
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12
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Palmgren M. P-type ATPases: Many more enigmas left to solve. J Biol Chem 2023; 299:105352. [PMID: 37838176 PMCID: PMC10654040 DOI: 10.1016/j.jbc.2023.105352] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/02/2023] [Accepted: 10/05/2023] [Indexed: 10/16/2023] Open
Abstract
P-type ATPases constitute a large ancient super-family of primary active pumps that have diverse substrate specificities ranging from H+ to phospholipids. The significance of these enzymes in biology cannot be overstated. They are structurally related, and their catalytic cycles alternate between high- and low-affinity conformations that are induced by phosphorylation and dephosphorylation of a conserved aspartate residue. In the year 1988, all P-type sequences available by then were analyzed and five major families, P1 to P5, were identified. Since then, a large body of knowledge has accumulated concerning the structure, function, and physiological roles of members of these families, but only one additional family, P6 ATPases, has been identified. However, much is still left to be learned. For each family a few remaining enigmas are presented, with the intention that they will stimulate interest in continued research in the field. The review is by no way comprehensive and merely presents personal views with a focus on evolution.
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Affiliation(s)
- Michael Palmgren
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark.
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13
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Paweletz LC, Holtbrügge SL, Löb M, De Vecchis D, Schäfer LV, Günther Pomorski T, Justesen BH. Anionic Phospholipids Stimulate the Proton Pumping Activity of the Plant Plasma Membrane P-Type H +-ATPase. Int J Mol Sci 2023; 24:13106. [PMID: 37685912 PMCID: PMC10488199 DOI: 10.3390/ijms241713106] [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: 08/03/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023] Open
Abstract
The activity of membrane proteins depends strongly on the surrounding lipid environment. Here, we characterize the lipid stimulation of the plant plasma membrane H+-ATPase Arabidopsis thaliana H+-ATPase isoform 2 (AHA2) upon purification and reconstitution into liposomes of defined lipid compositions. We show that the proton pumping activity of AHA2 is stimulated by anionic phospholipids, especially by phosphatidylserine. This activation was independent of the cytoplasmic C-terminal regulatory domain of the pump. Molecular dynamics simulations revealed several preferential contact sites for anionic phospholipids in the transmembrane domain of AHA2. These contact sites are partially conserved in functionally different P-type ATPases from different organisms, suggesting a general regulation mechanism by the membrane lipid environment. Our findings highlight the fact that anionic lipids play an important role in the control of H+-ATPase activity.
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Affiliation(s)
- Laura C. Paweletz
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.C.P.); (M.L.); (T.G.P.)
| | - Simon L. Holtbrügge
- Center for Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (S.L.H.); (D.D.V.)
| | - Malina Löb
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.C.P.); (M.L.); (T.G.P.)
| | - Dario De Vecchis
- Center for Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (S.L.H.); (D.D.V.)
| | - Lars V. Schäfer
- Center for Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (S.L.H.); (D.D.V.)
| | - Thomas Günther Pomorski
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.C.P.); (M.L.); (T.G.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Bo Højen Justesen
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44780 Bochum, Germany; (L.C.P.); (M.L.); (T.G.P.)
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14
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Bailey MLP, Pratt SE, Hinrichsen M, Zhang Y, Bewersdorf J, Regan LJ, Mochrie SGJ. Uncovering diffusive states of the yeast membrane protein, Pma1, and how labeling method can change diffusive behavior. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:42. [PMID: 37294385 PMCID: PMC10369454 DOI: 10.1140/epje/s10189-023-00301-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 05/15/2023] [Indexed: 06/10/2023]
Abstract
We present and analyze video-microscopy-based single-particle-tracking measurements of the budding yeast (Saccharomyces cerevisiae) membrane protein, Pma1, fluorescently labeled either by direct fusion to the switchable fluorescent protein, mEos3.2, or by a novel, light-touch, labeling scheme, in which a 5 amino acid tag is directly fused to the C-terminus of Pma1, which then binds mEos3.2. The track diffusivity distributions of these two populations of single-particle tracks differ significantly, demonstrating that labeling method can be an important determinant of diffusive behavior. We also applied perturbation expectation maximization (pEMv2) (Koo and Mochrie in Phys Rev E 94(5):052412, 2016), which sorts trajectories into the statistically optimum number of diffusive states. For both TRAP-labeled Pma1 and Pma1-mEos3.2, pEMv2 sorts the tracks into two diffusive states: an essentially immobile state and a more mobile state. However, the mobile fraction of Pma1-mEos3.2 tracks is much smaller ([Formula: see text]) than the mobile fraction of TRAP-labeled Pma1 tracks ([Formula: see text]). In addition, the diffusivity of Pma1-mEos3.2's mobile state is several times smaller than the diffusivity of TRAP-labeled Pma1's mobile state. Thus, the two different labeling methods give rise to very different overall diffusive behaviors. To critically assess pEMv2's performance, we compare the diffusivity and covariance distributions of the experimental pEMv2-sorted populations to corresponding theoretical distributions, assuming that Pma1 displacements realize a Gaussian random process. The experiment-theory comparisons for both the TRAP-labeled Pma1 and Pma1-mEos3.2 reveal good agreement, bolstering the pEMv2 approach.
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Affiliation(s)
- Mary Lou P Bailey
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, CT, 06511, USA
- Department of Applied Physics, Yale University, New Haven, CT, 06511, USA
| | - Susan E Pratt
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, CT, 06511, USA
- Department of Physics, Yale University, New Haven, CT, 06511, USA
| | | | - Yongdeng Zhang
- Department of Cell Biology, Yale University, New Haven, CT, 06511, USA
| | - Joerg Bewersdorf
- Department of Applied Physics, Yale University, New Haven, CT, 06511, USA
- Department of Physics, Yale University, New Haven, CT, 06511, USA
- Department of Cell Biology, Yale University, New Haven, CT, 06511, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06511, USA
| | - Lynne J Regan
- Institute of Quantitative Biology, Biochemistry and Biotechnology, Center for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, 06511, UK
| | - Simon G J Mochrie
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, CT, 06511, USA.
- Department of Applied Physics, Yale University, New Haven, CT, 06511, USA.
- Department of Physics, Yale University, New Haven, CT, 06511, USA.
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15
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Structural and Functional Diversity of Two ATP-Driven Plant Proton Pumps. Int J Mol Sci 2023; 24:ijms24054512. [PMID: 36901943 PMCID: PMC10003446 DOI: 10.3390/ijms24054512] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/09/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
Two ATP-dependent proton pumps function in plant cells. Plasma membrane H+-ATPase (PM H+-ATPase) transfers protons from the cytoplasm to the apoplast, while vacuolar H+-ATPase (V-ATPase), located in tonoplasts and other endomembranes, is responsible for proton pumping into the organelle lumen. Both enzymes belong to two different families of proteins and, therefore, differ significantly in their structure and mechanism of action. The plasma membrane H+-ATPase is a member of the P-ATPases that undergo conformational changes, associated with two distinct E1 and E2 states, and autophosphorylation during the catalytic cycle. The vacuolar H+-ATPase represents rotary enzymes functioning as a molecular motor. The plant V-ATPase consists of thirteen different subunits organized into two subcomplexes, the peripheral V1 and the membrane-embedded V0, in which the stator and rotor parts have been distinguished. In contrast, the plant plasma membrane proton pump is a functional single polypeptide chain. However, when the enzyme is active, it transforms into a large twelve-protein complex of six H+-ATPase molecules and six 14-3-3 proteins. Despite these differences, both proton pumps can be regulated by the same mechanisms (such as reversible phosphorylation) and, in some processes, such as cytosolic pH regulation, may act in a coordinated way.
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16
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The evolution of plant proton pump regulation via the R domain may have facilitated plant terrestrialization. Commun Biol 2022; 5:1312. [PMID: 36446861 PMCID: PMC9708826 DOI: 10.1038/s42003-022-04291-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 11/23/2022] [Indexed: 11/30/2022] Open
Abstract
Plasma membrane (PM) H+-ATPases are the electrogenic proton pumps that export H+ from plant and fungal cells to acidify the surroundings and generate a membrane potential. Plant PM H+-ATPases are equipped with a C‑terminal autoinhibitory regulatory (R) domain of about 100 amino acid residues, which could not be identified in the PM H+-ATPases of green algae but appeared fully developed in immediate streptophyte algal predecessors of land plants. To explore the physiological significance of this domain, we created in vivo C-terminal truncations of autoinhibited PM H+‑ATPase2 (AHA2), one of the two major isoforms in the land plant Arabidopsis thaliana. As more residues were deleted, the mutant plants became progressively more efficient in proton extrusion, concomitant with increased expansion growth and nutrient uptake. However, as the hyperactivated AHA2 also contributed to stomatal pore opening, which provides an exit pathway for water and an entrance pathway for pests, the mutant plants were more susceptible to biotic and abiotic stresses, pathogen invasion and water loss, respectively. Taken together, our results demonstrate that pump regulation through the R domain is crucial for land plant fitness and by controlling growth and nutrient uptake might have been necessary already for the successful water-to-land transition of plants.
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17
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Petrovich GD, Corradi GR, Adamo HP. The effect of metal ions on the Spf1p P5A-ATPase. High sensitivity to irreversible inhibition by zinc. Arch Biochem Biophys 2022; 732:109450. [DOI: 10.1016/j.abb.2022.109450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/26/2022] [Accepted: 10/27/2022] [Indexed: 11/05/2022]
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18
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Marrink SJ, Monticelli L, Melo MN, Alessandri R, Tieleman DP, Souza PCT. Two decades of Martini: Better beads, broader scope. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2022. [DOI: 10.1002/wcms.1620] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Siewert J. Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials University of Groningen Groningen The Netherlands
| | - Luca Monticelli
- Molecular Microbiology and Structural Biochemistry (MMSB ‐ UMR 5086) CNRS & University of Lyon Lyon France
| | - Manuel N. Melo
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras Portugal
| | - Riccardo Alessandri
- Pritzker School of Molecular Engineering University of Chicago Chicago Illinois USA
| | - D. Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences University of Calgary Alberta Canada
| | - Paulo C. T. Souza
- Molecular Microbiology and Structural Biochemistry (MMSB ‐ UMR 5086) CNRS & University of Lyon Lyon France
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Primo C, Navarre C, Chaumont F, André B. Plasma membrane H +-ATPases promote TORC1 activation in plant suspension cells. iScience 2022; 25:104238. [PMID: 35494253 PMCID: PMC9046228 DOI: 10.1016/j.isci.2022.104238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/25/2022] [Accepted: 03/30/2022] [Indexed: 11/28/2022] Open
Abstract
The TORC1 (Target of Rapamycin Complex 1) kinase complex plays a pivotal role in controlling cell growth in probably all eukaryotic species. The signals and mechanisms regulating TORC1 have been intensely studied in mammals but those of fungi and plants are much less known. We have previously reported that the yeast plasma membrane H+-ATPase Pma1 promotes TORC1 activation when stimulated by cytosolic acidification or nutrient-uptake-coupled H+ influx. Furthermore, a homologous plant H+-ATPase can substitute for yeast Pma1 to promote this H+-elicited TORC1 activation. We here report that TORC1 activity in Nicotiana tabacum BY-2 cells is also strongly influenced by the activity of plasma membrane H+-ATPases. In particular, stimulation of H+-ATPases by fusicoccin activates TORC1, and this response is also observed in cells transferred to a nutrient-free and auxin-free medium. Our results suggest that plant H+-ATPases, known to be regulated by practically all factors controlling cell growth, contribute to TOR signaling. Isolation of a tobacco BY-2 cell line suitable for analyzing TOR signaling Activation of plasma membrane H+-ATPases in BY-2 suspension cells elicits TOR signaling TOR signaling upon H+-ATPase activation also occurs in the absence of nutrients and auxin
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Affiliation(s)
- Cecilia Primo
- Molecular Physiology of the Cell, Université Libre de Bruxelles (ULB), Biopark, B-6041 Gosselies, Belgium
| | - Catherine Navarre
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, B-1348 Louvain-la-Neuve, Belgium
| | - François Chaumont
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, B-1348 Louvain-la-Neuve, Belgium
| | - Bruno André
- Molecular Physiology of the Cell, Université Libre de Bruxelles (ULB), Biopark, B-6041 Gosselies, Belgium
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