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Contreras RG, Torres-Carrillo A, Flores-Maldonado C, Shoshani L, Ponce A. Na +/K +-ATPase: More than an Electrogenic Pump. Int J Mol Sci 2024; 25:6122. [PMID: 38892309 PMCID: PMC11172918 DOI: 10.3390/ijms25116122] [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: 03/26/2024] [Revised: 05/20/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
The sodium pump, or Na+/K+-ATPase (NKA), is an essential enzyme found in the plasma membrane of all animal cells. Its primary role is to transport sodium (Na+) and potassium (K+) ions across the cell membrane, using energy from ATP hydrolysis. This transport creates and maintains an electrochemical gradient, which is crucial for various cellular processes, including cell volume regulation, electrical excitability, and secondary active transport. Although the role of NKA as a pump was discovered and demonstrated several decades ago, it remains the subject of intense research. Current studies aim to delve deeper into several aspects of this molecular entity, such as describing its structure and mode of operation in atomic detail, understanding its molecular and functional diversity, and examining the consequences of its malfunction due to structural alterations. Additionally, researchers are investigating the effects of various substances that amplify or decrease its pumping activity. Beyond its role as a pump, growing evidence indicates that in various cell types, NKA also functions as a receptor for cardiac glycosides like ouabain. This receptor activity triggers the activation of various signaling pathways, producing significant morphological and physiological effects. In this report, we present the results of a comprehensive review of the most outstanding studies of the past five years. We highlight the progress made regarding this new concept of NKA and the various cardiac glycosides that influence it. Furthermore, we emphasize NKA's role in epithelial physiology, particularly its function as a receptor for cardiac glycosides that trigger intracellular signals regulating cell-cell contacts, proliferation, differentiation, and adhesion. We also analyze the role of NKA β-subunits as cell adhesion molecules in glia and epithelial cells.
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Affiliation(s)
| | | | | | | | - Arturo Ponce
- Department of Physiology, Biophysics and Neurosciences, CINVESTAV-IPN, Mexico City 07360, Mexico; (R.G.C.); (A.T.-C.); (C.F.-M.); (L.S.)
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2
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Aguilella M, Garciadeblás B, Fernández Pacios L, Benito B. Phylogenetic and Structure-Function Analyses of ENA ATPases: A Case Study of the ENA1 Protein from the Fungus Neurospora crassa. Int J Mol Sci 2023; 25:514. [PMID: 38203685 PMCID: PMC10779151 DOI: 10.3390/ijms25010514] [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: 11/28/2023] [Revised: 12/26/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
ENA transporters are a group of P-type ATPases that are characterized by actively moving Na+ or K+ out of the cell against their concentration gradient. The existence of these transporters was initially attributed to some fungi, although more recently they have also been identified in mosses, liverworts, and some protozoa. Given the current increase in the number of organisms whose genomes are completely sequenced, we set out to expand our knowledge about the existence of ENA in organisms belonging to other phylogenetic groups. For that, a hidden Markov model profile was constructed to identify homologous sequences to ENA proteins in protein databases. This analysis allowed us to identify the existence of ENA-type ATPases in the most primitive groups of fungi, as well as in other eukaryotic organisms not described so far. In addition, this study has allowed the identification of a possible new group of P-ATPases, initially proposed as ENA but which maintain phylogenetic distances with these proteins. Finally, this work has also addressed this study of the structure of ENA proteins, which remained unknown due to the lack of crystallographic data. For this purpose, a 3D structure prediction of the NcENA1 protein of the fungus Neurospora crassa was performed using AlphaFold2 software v2.3.1. From this structure, the electrostatic potential of the protein was analyzed. With all these data, the protein regions and the amino acids involved in the transport of Na+ or K+ ions across the membrane were proposed for the first time. Targeted mutagenesis of some of these residues has confirmed their relevant participation in the transport function of ENA proteins.
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Affiliation(s)
- Marcos Aguilella
- Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, Pozuelo de Alarcón, 28223 Madrid, Spain;
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain;
| | - Blanca Garciadeblás
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain;
| | - Luis Fernández Pacios
- Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, Pozuelo de Alarcón, 28223 Madrid, Spain;
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain;
| | - Begoña Benito
- Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, Pozuelo de Alarcón, 28223 Madrid, Spain;
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain;
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3
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Clarke RJ. Electrostatic switch mechanisms of membrane protein trafficking and regulation. Biophys Rev 2023; 15:1967-1985. [PMID: 38192346 PMCID: PMC10771482 DOI: 10.1007/s12551-023-01166-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 11/17/2023] [Indexed: 01/10/2024] Open
Abstract
Lipid-protein interactions are normally classified as either specific or general. Specific interactions refer to lipid binding to specific binding sites within a membrane protein, thereby modulating the protein's thermal stability or kinetics. General interactions refer to indirect effects whereby lipids affect membrane proteins by modulating the membrane's physical properties, e.g., its fluidity, thickness, or dipole potential. It is not widely recognized that there is a third distinct type of lipid-protein interaction. Intrinsically disordered N- or C-termini of membrane proteins can interact directly but nonspecifically with the surrounding membrane. Many peripheral membrane proteins are held to the cytoplasmic surface of the plasma membrane via a cooperative combination of two forces: hydrophobic anchoring and electrostatic attraction. An acyl chain, e.g., myristoyl, added post-translationally to one of the protein's termini inserts itself into the lipid matrix and helps hold peripheral membrane proteins onto the membrane. Electrostatic attraction occurs between positively charged basic amino acid residues (lysine and arginine) on one of the protein's terminal tails and negatively charged phospholipid head groups, such as phosphatidylserine. Phosphorylation of either serine or tyrosine residues on the terminal tails via regulatory protein kinases allows for an electrostatic switch mechanism to control trafficking of the protein. Kinase action reduces the positive charge on the protein's tail, weakening the electrostatic attraction and releasing the protein from the membrane. A similar mechanism regulates many integral membrane proteins, but here only electrostatic interactions are involved, and the electrostatic switch modulates protein activity by altering the stabilities of different protein conformational states.
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Affiliation(s)
- Ronald J. Clarke
- School of Chemistry, University of Sydney, Sydney, NSW 2006 Australia
- The University of Sydney Nano Institute, Sydney, NSW 2006 Australia
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4
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Middleton DA, Griffin J, Esmann M, Fedosova NU. Solid-state NMR chemical shift analysis for determining the conformation of ATP bound to Na,K-ATPase in its native membrane. RSC Adv 2023; 13:34836-34846. [PMID: 38035247 PMCID: PMC10685339 DOI: 10.1039/d3ra06236h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 11/16/2023] [Indexed: 12/02/2023] Open
Abstract
Structures of membrane proteins determined by X-ray crystallography and, increasingly, by cryo-electron microscopy often fail to resolve the structural details of unstable or reactive small molecular ligands in their physiological sites. This work demonstrates that 13C chemical shifts measured by magic-angle spinning (MAS) solid-state NMR (SSNMR) provide unique information on the conformation of a labile ligand in the physiological site of a functional protein in its native membrane, by exploiting freeze-trapping to stabilise the complex. We examine the ribose conformation of ATP in a high affinity complex with Na,K-ATPase (NKA), an enzyme that rapidly hydrolyses ATP to ADP and inorganic phosphate under physiological conditions. The 13C SSNMR spectrum of the frozen complex exhibits peaks from all ATP ribose carbon sites and some adenine base carbons. Comparison of experimental chemical shifts with density functional theory (DFT) calculations of ATP in different conformations and protein environments reveals that the ATP ribose ring adopts an C3'-endo (N) conformation when bound with high affinity to NKA in the E1Na state, in contrast to the C2'-endo (S) ribose conformations of ATP bound to the E2P state and AMPPCP in the E1 complex. Additional dipolar coupling-mediated measurements of H-C-C-H torsional angles are used to eliminate possible relative orientations of the ribose and adenine rings. The utilization of chemical shifts to determine membrane protein ligand conformations has been underexploited to date and here we demonstrate this approach to be a powerful tool for resolving the fine details of ligand-protein interactions.
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Affiliation(s)
- David A Middleton
- Department of Chemistry, Lancaster University Bailrigg Lancaster LA1 4YB UK +44 (0)1524 594328
| | - John Griffin
- Department of Chemistry, Lancaster University Bailrigg Lancaster LA1 4YB UK +44 (0)1524 594328
| | - Mikael Esmann
- Department of Biomedicine, Aarhus University Aarhus Denmark
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Abe K, Nishizawa T, Artigas P. An unusual conformation from Na +-sensitive non-gastric proton pump mutants reveals molecular mechanisms of cooperative Na +-binding. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119543. [PMID: 37482134 DOI: 10.1016/j.bbamcr.2023.119543] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/29/2023] [Accepted: 07/14/2023] [Indexed: 07/25/2023]
Abstract
The Na+,K+-ATPase (NKA) and non-gastric H+,K+- ATPase (ngHKA) share ~65 % sequence identity, and nearly identical catalytic cycles. These pumps alternate between inward-facing (E1) and outward-facing (E2) conformations and differ in their exported substrate (Na+ or H+) and stoichiometries (3 Na+:2 K+ or 1 H+:1 K+). We reported that structures of the NKA-mimetic ngHKA mutant K794S/A797P/W940/R949C (SPWC) with 2 K+ occluded in E2-Pi and 3 Na+-bound in E1·ATP states were nearly identical to NKA structures in equivalent states. Here we report the cryo-EM structures of K794A and K794S, two poorly-selective ngHKA mutants, under conditions to stabilize the E1·ATP state. Unexpectedly, the structures show a hybrid with both E1- and E2-like structural features. While transmembrane segments TM1-TM3 and TM4's extracellular half adopted an E2-like conformation, the rest of the protein assumed an E1 configuration. Two spherical densities, likely bound Na+, were observed at cation-binding sites I and III, without density at site II. This explains the E2-like conformation of TM4's exoplasmic half. In NKA, oxygen atoms derived from the unwound portion of TM4 coordinated Na+ at site II. Thus, the lack of Na+ at site II of K794A/S prevents the luminal portion of TM4 from taking an E1-like position. The K794A structure also suggests that incomplete coordination of Na+ at site III induces the halfway rotation of TM6, which impairs Na+-binding at the site II. Thus, our observations provide insight into the molecular mechanism of E2-E1 transition and cooperative Na+-binding in the NKA and other related cation pumps.
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Affiliation(s)
- Kazuhiro Abe
- Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya 464-8601, Japan; Cellular and Structural Physiology Institute, Nagoya University, Nagoya 464-8601, Japan; Center for One Medicine Innovative Translational Research, Gifu University Institute for Advanced Study, Japan.
| | - Tomohiro Nishizawa
- Graduate School of Medical Life Sciences, Yokohama City University, Tsurumi, Yokohama 230-0045, Japan
| | - Pablo Artigas
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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6
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Mahato DR, Andersson M. Dynamic lipid interactions in the plasma membrane Na +,K +-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119545. [PMID: 37481079 DOI: 10.1016/j.bbamcr.2023.119545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 06/12/2023] [Accepted: 07/13/2023] [Indexed: 07/24/2023]
Abstract
The function of ion-transporting Na+,K+-ATPases depends on the surrounding lipid environment in biological membranes. Two established lipid-interaction sites A and B within the transmembrane domain have been observed to induce protein activation and stabilization, respectively. In addition, lipid-mediated inhibition has been assigned to a site C, but with the exact location not experimentally confirmed. Also, possible effects on lipid interactions by disease mutants dwelling in the membrane-protein interface remain relatively uncharacterized. We simulated human Na+,K+-ATPase α1β1FXYD homology models in E1 and E2 states in an asymmetric, multicomponent plasma membrane to determine both wild-type and disease mutant lipid-protein interactions. The simulated wild-type lipid interactions at the established sites A and B were in agreement with experimental results thereby confirming the membrane-protein model system. The less well-characterized, proposed inhibitory site C was dominated by lipids lacking inhibitory properties. Instead, two sites hosting inhibitory lipids were identified at the extracellular side and also a cytoplasmic CHL-binding site that provide putative alternative locations of Na+,K+-ATPase inhibition. Three disease mutations, Leu302Arg, Glu840Arg and Met859Arg resided in the lipid-protein interface and caused drastic changes in the lipid interactions. The simulation results show that lipid interactions to the human Na+,K+-ATPase α1β1FXYD protein in the plasma membrane are highly state-dependent and can be disturbed by disease mutations located in the lipid interface, which can open up for new venues to understand genetic disorders.
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Affiliation(s)
- Dhani Ram Mahato
- Department of Chemistry, Umeå University, Umeå, Sweden; Institut de Química Computacional i Catàlisi, Universitat de Girona, Girona, 17003, Spain
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7
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Lev B, Chennath M, Cranfield CG, Cornelius F, Allen TW, Clarke RJ. Involvement of the alpha-subunit N-terminus in the mechanism of the Na +,K +-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119539. [PMID: 37479188 DOI: 10.1016/j.bbamcr.2023.119539] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/26/2023] [Accepted: 07/10/2023] [Indexed: 07/23/2023]
Abstract
Previous studies have shown that cytoplasmic K+ release and the associated E2 → E1 conformational change of the Na+,K+-ATPase is a major rate-determining step of the enzyme's ion pumping cycle and hence a prime site of acute regulatory intervention. From the ionic strength dependence of the enzyme's distribution between the E2 and E1 states, it has also been found that E2 is stabilized by an electrostatic attraction. Any disruption of this electrostatic attraction would, thus, have profound effects on the rate of ion pumping. The aim of this paper is to identify the location of this interaction. Using enhanced-sampling molecular dynamics simulations with a predicted N-terminal structure added to the X-ray crystal structure of the Na+,K+-ATPase, a previously postulated salt bridge between Lys32 and Glu233 (rat sequence numbering) of the enzyme's α-subunit can be excluded. The residues never approach closely enough to form a salt bridge. In contrast, strong interactions with anionic lipid head groups were seen. To investigate the possibility of a protein-lipid interaction experimentally, the surface charge density of Na+,K+-ATPase-containing membrane fragments was estimated from zeta potential measurements to be 0.019 (± 0.001) C m-2. This is in good agreement with the charge density previously determined to be responsible for stabilization of the E2 state of 0.023 (± 0.009) C m-2 and the membrane charge density estimated here from published electron-microscopic images of 0.018C m-2. The results are, therefore, consistent with an interaction of the Na+,K+-ATPase α-subunit N-terminus with negatively-charged lipid head groups of the neighbouring cytoplasmic membrane surface as the origin of the electrostatic interaction stabilising the E2 state.
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Affiliation(s)
- B Lev
- School of Science, RMIT University, Melbourne, Vic, 3001, Australia
| | - M Chennath
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - C G Cranfield
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - F Cornelius
- Department of Biomedicine, University of Aarhus, DK-8000 Aarhus, C, Denmark
| | - T W Allen
- School of Science, RMIT University, Melbourne, Vic, 3001, Australia
| | - R J Clarke
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, Sydney, NSW 2006, Australia.
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8
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Palmgren M. Evolution of the sodium pump. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119511. [PMID: 37301269 DOI: 10.1016/j.bbamcr.2023.119511] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/16/2023] [Accepted: 06/02/2023] [Indexed: 06/12/2023]
Abstract
Eukaryotic plasma membranes (PMs) are energized by electrogenic P-type ATPases that generate either Na+ or H+ motive forces to drive Na+ and H+ dependent transport processes, respectively. For this purpose, animal rely on Na+/K+-ATPases whereas fungi and plants employ PM H+-ATPases. Prokaryotes, on the other hand, depend on H+ or Na+-motive electron transport complexes to energize their cell membranes. This raises the question as to why and when electrogenic Na+ and H+ pumps evolved? Here it is shown that prokaryotic Na+/K+-ATPases have near perfect conservation of binding sites involved in coordination of three Na+ and two K+ ions. Such pumps are rare in Eubacteria but are common in methanogenic Archaea where they often are found together with P-type putative PM H+-ATPases. With some exceptions, Na+/K+-ATPases and PM H+-ATPases are found everywhere in the eukaryotic tree of life, but never together in animals, fungi and land plants. It is hypothesized that Na+/K+-ATPases and PM H+-ATPases evolved in methanogenic Archaea to support the bioenergetics of these ancestral organisms, which can utilize both H+ and Na+ as energy currencies. Both pumps must have been simultaneously present in the first eukaryotic cell, but during diversification of the major eukaryotic kingdoms, and at the time animals diverged from fungi, animals kept Na+/K+-ATPases but lost PM H+-ATPases. At the same evolutionary branch point, fungi did loose Na+/K+-ATPases, and their role was taken over by PM H+-ATPases. An independent but similar scenery emerged during terrestrialization of plants: they lost Na+/K+-ATPases but kept PM H+-ATPases.
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Affiliation(s)
- Michael Palmgren
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
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9
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Peluffo RD, Hernández JA. The Na +,K +-ATPase and its stoichiometric ratio: some thermodynamic speculations. Biophys Rev 2023; 15:539-552. [PMID: 37681108 PMCID: PMC10480117 DOI: 10.1007/s12551-023-01082-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/18/2023] [Indexed: 09/09/2023] Open
Abstract
Almost seventy years after its discovery, the sodium-potassium adenosine triphosphatase (the sodium pump) located in the cell plasma membrane remains a source of novel mechanistic and physiologic findings. A noteworthy feature of this enzyme/transporter is its robust stoichiometric ratio under physiological conditions: it sequentially counter-transports three sodium ions and two potassium ions against their electrochemical potential gradients per each hydrolyzed ATP molecule. Here we summarize some present knowledge about the sodium pump and its physiological roles, and speculate whether energetic constraints may have played a role in the evolutionary selection of its characteristic stoichiometric ratio.
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Affiliation(s)
- R. Daniel Peluffo
- Group of Biophysical Chemistry, Department of Biological Sciences, CENUR Litoral Norte, Universidad de La República, Rivera 1350, CP: 50000 Salto, Uruguay
| | - Julio A. Hernández
- Biophysics and Systems Biology Section, Department of Cell and Molecular Biology, Facultad de Ciencias, Universidad de La República, Iguá 4225, CP: 11400 Montevideo, Uruguay
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10
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Lipid peroxidation increases membrane tension, Piezo1 gating, and cation permeability to execute ferroptosis. Curr Biol 2023; 33:1282-1294.e5. [PMID: 36898371 DOI: 10.1016/j.cub.2023.02.060] [Citation(s) in RCA: 48] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 12/13/2022] [Accepted: 02/16/2023] [Indexed: 03/11/2023]
Abstract
The ongoing metabolic and microbicidal pathways that support and protect cellular life generate potentially damaging reactive oxygen species (ROS). To counteract damage, cells express peroxidases, which are antioxidant enzymes that catalyze the reduction of oxidized biomolecules. Glutathione peroxidase 4 (GPX4) is the major hydroperoxidase specifically responsible for reducing lipid peroxides; this homeostatic mechanism is essential, and its inhibition causes a unique type of lytic cell death, ferroptosis. The mechanism(s) that lead to cell lysis in ferroptosis, however, are unclear. We report that the lipid peroxides formed during ferroptosis accumulate preferentially at the plasma membrane. Oxidation of surface membrane lipids increased tension on the plasma membrane and led to the activation of Piezo1 and TRP channels. Oxidized membranes thus became permeable to cations, ultimately leading to the gain of cellular Na+ and Ca2+ concomitant with loss of K+. These effects were reduced by deletion of Piezo1 and completely inhibited by blocking cation channel conductance with ruthenium red or 2-aminoethoxydiphenyl borate (2-APB). We also found that the oxidation of lipids depressed the activity of the Na+/K+-ATPase, exacerbating the dissipation of monovalent cation gradients. Preventing the changes in cation content attenuated ferroptosis. Altogether, our study establishes that increased membrane permeability to cations is a critical step in the execution of ferroptosis and identifies Piezo1, TRP channels, and the Na+/K+-ATPase as targets/effectors of this type of cell death.
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Manoj KM, Gideon DA, Bazhin NM, Tamagawa H, Nirusimhan V, Kavdia M, Jaeken L. Na,K-ATPase: A murzyme facilitating thermodynamic equilibriums at the membrane-interface. J Cell Physiol 2023; 238:109-136. [PMID: 36502470 DOI: 10.1002/jcp.30925] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 12/14/2022]
Abstract
The redox metabolic paradigm of murburn concept advocates that diffusible reactive species (DRS, particularly oxygen-centric radicals) are mainstays of physiology, and not mere pathological manifestations. The murburn purview of cellular function also integrates the essential principles of bioenergetics, thermogenesis, homeostasis, electrophysiology, and coherence. In this context, any enzyme that generates/modulates/utilizes/sustains DRS functionality is called a murzyme. We have demonstrated that several water-soluble (peroxidases, lactate dehydrogenase, hemogoblin, etc.) and membrane-embedded (Complexes I-V in mitochondria, Photosystems I/II in chloroplasts, rhodopsin/transducin in rod cells, etc.) proteins serve as murzymes. The membrane protein of Na,K-ATPase (NKA, also known as sodium-potassium pump) is the focus of this article, owing to its centrality in neuro-cardio-musculo electrophysiology. Herein, via a series of critical queries starting from the geometric/spatio-temporal considerations of diffusion/mass transfer of solutes in cells to an update on structural/distributional features of NKA in diverse cellular systems, and from various mechanistic aspects of ion-transport (thermodynamics, osmoregulation, evolutionary dictates, etc.) to assays/explanations of inhibitory principles like cardiotonic steroids (CTS), we first highlight some unresolved problems in the field. Thereafter, we propose and apply a minimalist murburn model of trans-membrane ion-differentiation by NKA to address the physiological inhibitory effects of trans-dermal peptide, lithium ion, volatile anesthetics, confirmed interfacial DRS + proton modulators like nitrophenolics and unsaturated fatty acid, and the diverse classes of molecules like CTS, arginine, oximes, etc. These explanations find a pan-systemic connectivity with the inhibitions/uncouplings of other membrane proteins in cells.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2, Kerala, India
| | - Daniel A Gideon
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2, Kerala, India
| | - Nikolai M Bazhin
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk, Russia
| | - Hirohisa Tamagawa
- Department of Mechanical Engineering, Gifu University, Gifu City, Japan
| | - Vijay Nirusimhan
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2, Kerala, India
| | - Mahendra Kavdia
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
| | - Laurent Jaeken
- Department of Industrial Sciences and Technology, Karel de Grote-Hogeschool, Antwerp University Association, Antwerp, Belgium
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12
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Faraj SE, Valsecchi WM, Ferreira-Gomes M, Centeno M, Saint Martin EM, Fedosova NU, Rossi JPFC, Montes MR, Rossi RC. Measurements of Na +-occluded intermediates during the catalytic cycle of the Na +/K +-ATPase provide novel insights into the mechanism of Na + transport. J Biol Chem 2022; 299:102811. [PMID: 36539036 PMCID: PMC9860123 DOI: 10.1016/j.jbc.2022.102811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
The Na+/K+-ATPase is an integral plasma membrane glycoprotein of all animal cells that couples the exchange of intracellular Na+ for extracellular K+ to the hydrolysis of ATP. The asymmetric distribution of Na+ and K+ is essential for cellular life and constitutes the physical basis of a series of fundamental biological phenomena. The pumping mechanism is explained by the Albers-Post model. It involves the presence of gates alternatively exposing Na+/K+-ATPase transport sites to the intracellular and extracellular sides and includes occluded states in which both gates are simultaneously closed. Unlike for K+, information is lacking about Na+-occluded intermediates, as occluded Na+ was only detected in states incapable of performing a catalytic cycle, including two Na+-containing crystallographic structures. The current knowledge is that intracellular Na+ must bind to the transport sites and become occluded upon phosphorylation by ATP to be transported to the extracellular medium. Here, taking advantage of epigallocatechin-3-gallate to instantaneously stabilize native Na+-occluded intermediates, we isolated species with tightly bound Na+ in an enzyme able to perform a catalytic cycle, consistent with a genuine occluded state. We found that Na+ becomes spontaneously occluded in the E1 dephosphorylated form of the Na+/K+-ATPase, exhibiting positive interactions between binding sites. In fact, the addition of ATP does not produce an increase in Na+ occlusion as it would have been expected; on the contrary, occluded Na+ transiently decreases, whereas ATP lasts. These results reveal new properties of E1 intermediates of the Albers-Post model for explaining the Na+ transport pathway.
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Affiliation(s)
- Santiago E. Faraj
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Wanda M. Valsecchi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Mariela Ferreira-Gomes
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Mercedes Centeno
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Elina Malén Saint Martin
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina
| | | | - Juan Pablo FC. Rossi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Mónica R. Montes
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - Rolando C. Rossi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) – Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina,For correspondence: Rolando C. Rossi
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13
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Sokolov VS. Investigations of Electrogenic Ion Transport by Na+,K+-ATPase in Bilayer Lipid Membranes by Impedance Method. BIOCHEMISTRY (MOSCOW), SUPPLEMENT SERIES A: MEMBRANE AND CELL BIOLOGY 2022. [DOI: 10.1134/s1990747822050117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Valsecchi WM, Faraj SE, Cerf NT, Fedosova NU, Montes MR. The transported cations impose differences in the thermostability of the gastric H,K-ATPase. A kinetic analysis. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184006. [PMID: 35868405 DOI: 10.1016/j.bbamem.2022.184006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/06/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
This work analyses the thermostability of a membrane protein, the gastric H,K-ATPase, by means of a detailed kinetic characterization of its inactivation process, which showed to exhibit first-order kinetics. We observed parallel time courses for the decrease of ATPase activity, the decrease of the autophosphorylation capacity and the loss of tertiary structure at 49 °C. Higher temperatures were required to induce a significant change in secondary structure. The correspondence between the kinetics of Trp fluorescence measured at 49 °C and the decrease of the residual activity after heating at that temperature, proves the irreversibility of the inactivation process. Inactivation proceeds at different rates in E1 or E2 conformations. The K+-induced E2 state exhibits a lower inactivation rate; the specific effect is exerted with a K0.5 similar to that found at 25 °C, providing a further inkling that K+ occlusion by the H,K-ATPase is not really favoured. Increasing [H+] from pH 8 to pH 7, which possibly shifts the protein to E1, produces a subtle destabilizing effect on the H,K-ATPase. We performed a prediction of potential intramolecular interactions and found that the differential stability between E1 and E2 may be mainly explained by the higher number of hydrophobic interactions in the α- and β-subunits of E2 conformation.
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Affiliation(s)
- W M Valsecchi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - S E Faraj
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - N T Cerf
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina
| | - N U Fedosova
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - M R Montes
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológicas "Prof. Alejandro C. Paladini" (IQUIFIB), Buenos Aires, Argentina.
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15
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Zou D, Wang Q, Chen T, Sang D, Yang T, Wang Y, Gao M, He F, Li Y, He L, Longzhu D. Bufadienolides originated from toad source and their anti-inflammatory activity. Front Pharmacol 2022; 13:1044027. [PMID: 36339575 PMCID: PMC9627299 DOI: 10.3389/fphar.2022.1044027] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 10/10/2022] [Indexed: 03/03/2024] Open
Abstract
Bufadienolide, an essential member of the C-24 steroid family, is characterized by an α-pyrone positioned at C-17. As the predominantly active constituent in traditional Chinese medicine of Chansu, bufadienolide has been prescribed in the treatment of numerous ailments. It is a specifically potent inhibitor of Na+/K+ ATPase with excellent anti-inflammatory activity. However, the severe side effects triggered by unbiased inhibition of the whole-body cells distributed α1-subtype of Na+/K+ ATPase, restrict its future applicability. Thus, researchers have paved the road for the structural alteration of desirable bufadienolide derivatives with minimal adverse effects via biotransformation. In this review, we give priority to the present evidence for structural diversity, MS fragmentation principles, anti-inflammatory efficacy, and structure modification of bufadienolides derived from toads to offer a scientific foundation for future in-depth investigations and views.
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Affiliation(s)
- Denglang Zou
- School of Life Science, Qinghai Normal University, Xining, China
- College of Pharmacy, Jinan University, Guangzhou, China
- Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Qiqi Wang
- College of Pharmacy, Jinan University, Guangzhou, China
| | - Tao Chen
- Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Duocheng Sang
- School of Life Science, Qinghai Normal University, Xining, China
| | - Tingqin Yang
- School of Life Science, Qinghai Normal University, Xining, China
| | - Yuhan Wang
- School of Life Science, Qinghai Normal University, Xining, China
| | - Mengze Gao
- School of Life Science, Qinghai Normal University, Xining, China
| | - Fangfang He
- School of Life Science, Qinghai Normal University, Xining, China
| | - Yulin Li
- Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Liangliang He
- College of Pharmacy, Jinan University, Guangzhou, China
| | - Duojie Longzhu
- School of Life Science, Qinghai Normal University, Xining, China
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16
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Moreno C, Jiao S, Yano S, Holmgren M. Disease mutations of human α3 Na +/K +-ATPase define extracellular Na + binding/occlusion kinetics at ion binding site III. PNAS NEXUS 2022; 1:pgac205. [PMID: 36304555 PMCID: PMC9585393 DOI: 10.1093/pnasnexus/pgac205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/23/2022] [Indexed: 11/06/2022]
Abstract
Na+/K+-ATPase, which creates transmembrane electrochemical gradients by exchanging 3 Na+ for 2 K+, is central to the pathogenesis of neurological diseases such as alternating hemiplegia of childhood. Although Na+/K+-ATPase has 3 distinct ion binding sites I-III, the difficulty of distinguishing ion binding events at each site from the others hinders kinetic study of these transitions. Here, we show that binding of Na+ at each site in the human α3 Na+/K+-ATPase can be resolved using extracellular Na+-mediated transient currents. When Na+/K+-ATPase is constrained to bind and release only Na+, three kinetic components: fast, medium, and slow, can be isolated, presumably corresponding to the protein dynamics associated with the binding (or release depending on the voltage step direction) and the occlusion (or deocclusion) of each of the 3 Na+. Patient-derived mutations of residues which coordinate Na+ at site III exclusively impact the slow component, demonstrating that site III is crucial for deocclusion and release of the first Na+ into the extracellular milieu. These results advance understanding of Na+/K+-ATPase mutation pathogenesis and provide a foundation for study of individual ions' binding kinetics.
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Affiliation(s)
- Cristina Moreno
- Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Song Jiao
- Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sho Yano
- Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA,Medical Genetics and Genomic Medicine Training Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Miguel Holmgren
- Correspondence should be addressed: Miguel Holmgren, Ph.D. Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. Tel: +1-(301) 451-6259; E-mail:
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17
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Structure and function of H +/K + pump mutants reveal Na +/K + pump mechanisms. Nat Commun 2022; 13:5270. [PMID: 36085139 PMCID: PMC9463140 DOI: 10.1038/s41467-022-32793-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/17/2022] [Indexed: 11/09/2022] Open
Abstract
Ion-transport mechanisms evolve by changing ion-selectivity, such as switching from Na+ to H+ selectivity in secondary-active transporters or P-type-ATPases. Here we study primary-active transport via P-type ATPases using functional and structural analyses to demonstrate that four simultaneous residue substitutions transform the non-gastric H+/K+ pump, a strict H+-dependent electroneutral P-type ATPase, into a bona fide Na+-dependent electrogenic Na+/K+ pump. Conversion of a H+-dependent primary-active transporter into a Na+-dependent one provides a prototype for similar studies of ion-transport proteins. Moreover, we solve the structures of the wild-type non-gastric H+/K+ pump, a suitable drug target to treat cystic fibrosis, and of its Na+/K+ pump-mimicking mutant in two major conformations, providing insight on how Na+ binding drives a concerted mechanism leading to Na+/K+ pump phosphorylation.
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18
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Structural basis for gating mechanism of the human sodium-potassium pump. Nat Commun 2022; 13:5293. [PMID: 36075933 PMCID: PMC9458724 DOI: 10.1038/s41467-022-32990-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 08/25/2022] [Indexed: 12/03/2022] Open
Abstract
P2-type ATPase sodium-potassium pumps (Na+/K+-ATPases) are ion-transporting enzymes that use ATP to transport Na+ and K+ on opposite sides of the lipid bilayer against their electrochemical gradients to maintain ion concentration gradients across the membranes in all animal cells. Despite the available molecular architecture of the Na+/K+-ATPases, a complete molecular mechanism by which the Na+ and K+ ions access into and are released from the pump remains unknown. Here we report five cryo-electron microscopy (cryo-EM) structures of the human alpha3 Na+/K+-ATPase in its cytoplasmic side-open (E1), ATP-bound cytoplasmic side-open (E1•ATP), ADP-AlF4− trapped Na+-occluded (E1•P-ADP), BeF3− trapped exoplasmic side-open (E2P) and MgF42− trapped K+-occluded (E2•Pi) states. Our work reveals the atomically resolved structural detail of the cytoplasmic gating mechanism of the Na+/K+-ATPase. Through cryo-EM analysis, here authors reveal conformational rearrangements that are critical for the gating mechanism of the human alpha3 Na+/K+−ATPase
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19
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Fruergaard MU, Dach I, Andersen JL, Ozol M, Shasavar A, Quistgaard EM, Poulsen H, Fedosova NU, Nissen P. The Na,K-ATPase in complex with beryllium fluoride mimics an ATPase phosphorylated state. J Biol Chem 2022; 298:102317. [PMID: 35926706 PMCID: PMC9485054 DOI: 10.1016/j.jbc.2022.102317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 07/23/2022] [Accepted: 07/25/2022] [Indexed: 10/29/2022] Open
Abstract
The Na+,K+-ATPase generates electrochemical gradients of Na+ and K+ across the plasma membrane via a functional cycle that includes various phosphoenzyme intermediates. However, the structure and function of these intermediates and how metal fluorides mimick them require further investigation. Here, we describe a 4.0 Å resolution crystal structure and functional properties of the pig kidney Na+,K+-ATPase stabilized by the inhibitor beryllium fluoride (denoted E2-BeFx). E2-BeFx is expected to mimic properties of the E2P phosphoenzyme, yet with unknown characteristics of ion and ligand binding. The structure resembles the E2P form obtained by phosphorylation from inorganic phosphate (Pi) and stabilized by cardiotonic steroids, including a low-affinity Mg2+ site near ion binding site II. Our anomalous Fourier analysis of the crystals soaked in Rb+ (a K+ congener) followed by a low-resolution rigid-body refinement (6.9-7.5 Å) revealed pre-occlusion transitions leading to activation of the dephosphorylation reaction. We show that the Mg2+ location indicates a site of initial K+ recognition and acceptance upon binding to the outward-open E2P state after Na+ release. Furthermore, using binding and activity studies, we find that the BeFx-inhibited enzyme is also able to bind ADP/ATP and Na+. These results relate the E2-BeFx complex to a transient K+- and ADP-sensitive E*P intermediate of the functional cycle of the Na+,K+-ATPase, prior to E2P.
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Affiliation(s)
- Marlene U Fruergaard
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Dept. Molecular Biology and Genetics, DK - 8000 Aarhus C, Denmark
| | - Ingrid Dach
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Dept. Molecular Biology and Genetics, DK - 8000 Aarhus C, Denmark
| | - Jacob L Andersen
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Dept. Molecular Biology and Genetics, DK - 8000 Aarhus C, Denmark; Department of Biomedicine, Aarhus University, DK - 8000 Aarhus C, Denmark
| | - Mette Ozol
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Dept. Molecular Biology and Genetics, DK - 8000 Aarhus C, Denmark
| | - Azadeh Shasavar
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Dept. Molecular Biology and Genetics, DK - 8000 Aarhus C, Denmark
| | - Esben M Quistgaard
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Dept. Molecular Biology and Genetics, DK - 8000 Aarhus C, Denmark
| | - Hanne Poulsen
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Dept. Molecular Biology and Genetics, DK - 8000 Aarhus C, Denmark
| | - Natalya U Fedosova
- Department of Biomedicine, Aarhus University, DK - 8000 Aarhus C, Denmark.
| | - Poul Nissen
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Dept. Molecular Biology and Genetics, DK - 8000 Aarhus C, Denmark.
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20
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Guo Y, Zhang Y, Yan R, Huang B, Ye F, Wu L, Chi X, Shi Y, Zhou Q. Cryo-EM structures of recombinant human sodium-potassium pump determined in three different states. Nat Commun 2022; 13:3957. [PMID: 35803952 PMCID: PMC9270386 DOI: 10.1038/s41467-022-31602-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 06/24/2022] [Indexed: 11/09/2022] Open
Abstract
Sodium-Potassium Pump (Na+/K+-ATPase, NKA) is an ion pump that generates an electrochemical gradient of sodium and potassium ions across the plasma membrane by hydrolyzing ATP. During each Post-Albers cycle, NKA exchanges three cytoplasmic sodium ions for two extracellular potassium ions through alternating changes between the E1 and E2 states. Hitherto, several steps remained unknown during the complete working cycle of NKA. Here, we report cryo-electron microscopy (cryo-EM) structures of recombinant human NKA (hNKA) in three distinct states at 2.7–3.2 Å resolution, representing the E1·3Na and E1·3Na·ATP states with cytosolic gates open and the basic E2·[2K] state, respectively. This work provides the insights into the cytoplasmic Na+ entrance pathway and the mechanism of cytoplasmic gate closure coupled with ATP hydrolysis, filling crucial gaps in the structural elucidation of the Post-Albers cycle of NKA. Sodium-Potassium Pump (Na+/K+-ATPase, NKA) generates an electrochemical gradient of sodium and potassium ions across the plasma membrane by hydrolyzing ATP. Here, the authors report structures of human NKA providing insight into the cytoplasmic Na+ entrance and the cytoplasmic gate closure coupled to ATP hydrolysis.
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Affiliation(s)
- Yingying Guo
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Department of Biochemistry, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yuanyuan Zhang
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Renhong Yan
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Department of Biochemistry, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Bangdong Huang
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Fangfei Ye
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Liushu Wu
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Ximin Chi
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Yi Shi
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Qiang Zhou
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China. .,Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China.
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21
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Role of Omics in Migraine Research and Management: A Narrative Review. Mol Neurobiol 2022; 59:5809-5834. [PMID: 35796901 DOI: 10.1007/s12035-022-02930-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 06/14/2022] [Indexed: 10/17/2022]
Abstract
Migraine is a neurological disorder defined by episodic attacks of chronic pain associated with nausea, photophobia, and phonophobia. It is known to be a complex disease with several environmental and genetic factors contributing to its susceptibility. Risk factors for migraine include head or neck injury (Arnold, Cephalalgia 38(1):1-211, 2018). Stress and high temperature are known to trigger migraine, while sleep disorders and anxiety are considered to be the comorbid conditions with migraine. Studies have reported various biomarkers, including genetic variants, proteins, and metabolites implicated in migraine's pathophysiology. Using the "omics" approach, which deals with genetics, transcriptomics, proteomics, and metabolomics, more specific biomarkers for various migraine can be identified. On account of its multifactorial nature, migraine is an ideal study model focusing on integrated omics approaches, including genomics, transcriptomics, proteomics, and metabolomics. The current review has been compiled with an aim to focus on the genomic alterations especially involved in the regulation of glutamatergic neurotransmission, cortical excitability, ion channels, solute carrier proteins, or receptors; their expression in migraine patients and also specific proteins and metabolites, including some inflammatory biomarkers that might represent the migraine phenotype at the molecular level. The systems biology approach holds the promise to understand the pathophysiology of the disease at length and also to identify the specific therapeutic targets for novel interventions.
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22
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Duan R, Li HM, Hu WB, Hong CG, Chen ML, Cao J, Wang ZX, Chen CY, Yin F, Hu ZH, Li JD, Xie H, Liu ZZ. Recurrent de novo single point variant on the gene encoding Na +/K + pump results in epilepsy. Prog Neurobiol 2022; 216:102310. [PMID: 35724808 DOI: 10.1016/j.pneurobio.2022.102310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 04/28/2022] [Accepted: 06/15/2022] [Indexed: 10/18/2022]
Abstract
The etiology of epilepsy remains undefined in two-thirds of patients. Here, we identified a de novo variant of ATP1A2 (c.2426 T > G, p.Leu809Arg), which encodes the α2 subunit of Na+/K+-ATPase, from a family with idiopathic epilepsy. This variant caused epilepsy with hemiplegic migraine in the study patients. We generated the point variant mouse model Atp1a2L809R, which recapitulated the epilepsy observed in the study patients. In Atp1a2L809R/WT mice, convulsions were observed and cognitive and memory function was impaired. This variant affected the potassium binding function of the protein, disabling its ion transport ability, thereby increasing the frequency of nerve impulses. Valproate (VPA) and Carbamazepine (CBZ) have limited therapeutic efficacy in ameliorating the epileptic syndromes of Atp1a2L809R/WT mice. Our work revealed that ATP1A2L809R variants cause a predisposition to epilepsy. Moreover, we provide a point variant mouse model for epilepsy research and drug screening.
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Affiliation(s)
- Ran Duan
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Hong-Ming Li
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Wen-Bao Hu
- Institute of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Chun-Gu Hong
- Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Meng-Lu Chen
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jia Cao
- Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Zhen-Xing Wang
- Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Chun-Yuan Chen
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Zhong-Hua Hu
- Institute of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jia-Da Li
- State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China
| | - Hui Xie
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Hunan Key Laboratory of Organ Injury, Aging and Regenerative Medicine, Changsha, Hunan 410008, China; Hunan Key Laboratory of Bone Joint Degeneration and Injury, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, China.
| | - Zheng-Zhao Liu
- Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Hunan Key Laboratory of Organ Injury, Aging and Regenerative Medicine, Changsha, Hunan 410008, China.
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23
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Subsets of Slow Dynamic Modes Reveal Global Information Sources as Allosteric Sites. J Mol Biol 2022; 434:167644. [DOI: 10.1016/j.jmb.2022.167644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 05/17/2022] [Accepted: 05/17/2022] [Indexed: 02/06/2023]
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24
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Fedosova NU, Habeck M, Nissen P. Structure and Function of Na,K-ATPase-The Sodium-Potassium Pump. Compr Physiol 2021; 12:2659-2679. [PMID: 34964112 DOI: 10.1002/cphy.c200018] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Na,K-ATPase is an ubiquitous enzyme actively transporting Na-ions out of the cell in exchange for K-ions, thereby maintaining their concentration gradients across the cell membrane. Since its discovery more than six decades ago the Na-pump has been studied extensively and its vital physiological role in essentially every cell has been established. This article aims at providing an overview of well-established biochemical properties with a focus on Na,K-ATPase isoforms, its transport mechanism and principle conformations, inhibitors, and insights gained from crystal structures. © 2021 American Physiological Society. Compr Physiol 11:1-21, 2021.
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Affiliation(s)
| | - Michael Habeck
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
| | - Poul Nissen
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
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25
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Tomita A, Daiho T, Kusakizako T, Yamashita K, Ogasawara S, Murata T, Nishizawa T, Nureki O. Cryo-EM reveals mechanistic insights into lipid-facilitated polyamine export by human ATP13A2. Mol Cell 2021; 81:4799-4809.e5. [PMID: 34798056 DOI: 10.1016/j.molcel.2021.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/26/2021] [Accepted: 11/01/2021] [Indexed: 01/11/2023]
Abstract
The cytoplasmic polyamine maintains cellular homeostasis by chelating toxic metal cations, regulating transcriptional activity, and protecting DNA. ATP13A2 was identified as a lysosomal polyamine exporter responsible for polyamine release into the cytosol, and its dysfunction is associated with Alzheimer's disease and other neural degradation diseases. ATP13A2 belongs to the P5 subfamily of the P-type ATPase family, but its mechanisms remain unknown. Here, we report the cryoelectron microscopy (cryo-EM) structures of human ATP13A2 under four different conditions, revealing the structural coupling between the polyamine binding and the dephosphorylation. Polyamine is bound at the luminal tunnel and recognized through numerous electrostatic and π-cation interactions, explaining its broad specificity. The unique N-terminal domain is anchored to the lipid membrane to stabilize the E2P conformation, thereby accelerating the E1P-to-E2P transition. These findings reveal the distinct mechanism of P5B ATPases, thereby paving the way for neuroprotective therapy by activating ATP13A2.
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Affiliation(s)
- Atsuhiro Tomita
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takashi Daiho
- Department of Biochemistry, Asahikawa Medical University, Midorigaoka-Higashi, Asahikawa 078-8510, Japan
| | - Tsukasa Kusakizako
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Keitaro Yamashita
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Satoshi Ogasawara
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Takeshi Murata
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Tomohiro Nishizawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Graduate School of Medical Life Science, Yokohama City University, 1-7-29, Tsurumi, Yokohama 230-0045, Japan.
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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26
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Na/K-ATPase Ion Transport and Receptor-Mediated Signaling Pathways. J Membr Biol 2021; 254:443-446. [PMID: 34724099 DOI: 10.1007/s00232-021-00207-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2021] [Indexed: 10/19/2022]
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27
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Ygberg S, Akkuratov EE, Howard RJ, Taylan F, Jans DC, Mahato DR, Katz A, Kinoshita PF, Portal B, Nennesmo I, Lindskog M, Karlish SJD, Andersson M, Lindstrand A, Brismar H, Aperia A. A missense mutation converts the Na +,K +-ATPase into an ion channel and causes therapy-resistant epilepsy. J Biol Chem 2021; 297:101355. [PMID: 34717959 PMCID: PMC8637647 DOI: 10.1016/j.jbc.2021.101355] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 10/14/2021] [Accepted: 10/25/2021] [Indexed: 11/16/2022] Open
Abstract
The ion pump Na+,K+-ATPase is a critical determinant of neuronal excitability; however, its role in the etiology of diseases of the central nervous system (CNS) is largely unknown. We describe here the molecular phenotype of a Trp931Arg mutation of the Na+,K+-ATPase catalytic α1 subunit in an infant diagnosed with therapy-resistant lethal epilepsy. In addition to the pathological CNS phenotype, we also detected renal wasting of Mg2+. We found that membrane expression of the mutant α1 protein was low, and ion pumping activity was lost. Arginine insertion into membrane proteins can generate water-filled pores in the plasma membrane, and our molecular dynamic (MD) simulations of the principle states of Na+,K+-ATPase transport demonstrated massive water inflow into mutant α1 and destabilization of the ion-binding sites. MD simulations also indicated that a water pathway was created between the mutant arginine residue and the cytoplasm, and analysis of oocytes expressing mutant α1 detected a nonspecific cation current. Finally, neurons expressing mutant α1 were observed to be depolarized compared with neurons expressing wild-type protein, compatible with a lowered threshold for epileptic seizures. The results imply that Na+,K+-ATPase should be considered a neuronal locus minoris resistentia in diseases associated with epilepsy and with loss of plasma membrane integrity.
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Affiliation(s)
- Sofia Ygberg
- Neuropediatric Unit, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Centre for Inherited Metabolic Diseases (CMMS), Karolinska University Hospital, Stockholm, Sweden
| | - Evgeny E Akkuratov
- Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
| | - Rebecca J Howard
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Fulya Taylan
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Daniel C Jans
- Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
| | | | - Adriana Katz
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovoth, Israel
| | - Paula F Kinoshita
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Benjamin Portal
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Inger Nennesmo
- Department of Pathology, Karolinska University Hospital, Stockholm, Sweden
| | - Maria Lindskog
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Steven J D Karlish
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovoth, Israel
| | | | - Anna Lindstrand
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Hjalmar Brismar
- Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden; Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
| | - Anita Aperia
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
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28
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Zhang Y, Watanabe S, Tsutsumi A, Kadokura H, Kikkawa M, Inaba K. Cryo-EM analysis provides new mechanistic insight into ATP binding to Ca 2+ -ATPase SERCA2b. EMBO J 2021; 40:e108482. [PMID: 34459010 DOI: 10.15252/embj.2021108482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 12/31/2022] Open
Abstract
Sarco/endoplasmic reticulum Ca2+ -ATPase (SERCA) 2b is a ubiquitous SERCA family member that conducts Ca2+ uptake from the cytosol to the ER. Herein, we present a 3.3 Å resolution cryo-electron microscopy (cryo-EM) structure of human SERCA2b in the E1·2Ca2+ state, revealing a new conformation for Ca2+ -bound SERCA2b with a much closer arrangement of cytosolic domains than in the previously reported crystal structure of Ca2+ -bound SERCA1a. Multiple conformations generated by 3D classification of cryo-EM maps reflect the intrinsically dynamic nature of the cytosolic domains in this state. Notably, ATP binding residues of SERCA2b in the E1·2Ca2+ state are located at similar positions to those in the E1·2Ca2+ -ATP state; hence, the cryo-EM structure likely represents a preformed state immediately prior to ATP binding. Consistently, a SERCA2b mutant with an interdomain disulfide bridge that locks the closed cytosolic domain arrangement displayed significant autophosphorylation activity in the presence of Ca2+ . We propose a novel mechanism of ATP binding to SERCA2b.
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Affiliation(s)
- Yuxia Zhang
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
| | - Satoshi Watanabe
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
| | - Akihisa Tsutsumi
- Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Kadokura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
| | - Masahide Kikkawa
- Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
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29
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Displacement of the Na +/K + pump's transmembrane domains demonstrates conserved conformational changes in P-type 2 ATPases. Proc Natl Acad Sci U S A 2021; 118:2019317118. [PMID: 33597302 DOI: 10.1073/pnas.2019317118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cellular survival requires the ion gradients built by the Na+/K+ pump, an ATPase that alternates between two major conformations (E1 and E2). Here we use state-specific engineered-disulfide cross-linking to demonstrate that transmembrane segment 2 (M2) of the pump's α-subunit moves in directions that are inconsistent with distances observed in existing crystal structures of the Na+/K+ pump in E1 and E2. We characterize this movement with voltage-clamp fluorometry in single-cysteine mutants. Most mutants in the M1-M2 loop produced state-dependent fluorescence changes upon labeling with tetramethylrhodamine-6-maleimide (TMRM), which were due to quenching by multiple endogenous tryptophans. To avoid complications arising from multiple potential quenchers, we analyzed quenching of TMRM conjugated to R977C (in the static M9-M10 loop) by tryptophans introduced, one at a time, in M1-M2. This approach showed that tryptophans introduced in M2 quench TMRM only in E2, with D126W and L130W on the same helix producing the largest fluorescence changes. These observations indicate that M2 moves outward as Na+ is deoccluded from the E1 conformation, a mechanism consistent with cross-linking results and with proposals for other P-type 2 ATPases.
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30
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Abstract
KdpFABC is an oligomeric K+ transport complex in prokaryotes that maintains ionic homeostasis under stress conditions. The complex comprises a channel-like subunit (KdpA) from the superfamily of K+ transporters and a pump-like subunit (KdpB) from the superfamily of P-type ATPases. Recent structural work has defined the architecture and generated contradictory hypotheses for the transport mechanism. Here, we use substrate analogs to stabilize four key intermediates in the reaction cycle and determine the corresponding structures by cryogenic electron microscopy. We find that KdpB undergoes conformational changes consistent with other representatives from the P-type superfamily, whereas KdpA, KdpC, and KdpF remain static. We observe a series of spherical densities that we assign as K+ or water and which define a pathway for K+ transport. This pathway runs through an intramembrane tunnel in KdpA and delivers ions to sites in the membrane domain of KdpB. Our structures suggest a mechanism where ATP hydrolysis is coupled to K+ transfer between alternative sites in KdpB, ultimately reaching a low-affinity site where a water-filled pathway allows release of K+ to the cytoplasm.
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31
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Kryvenko V, Vagin O, Dada LA, Sznajder JI, Vadász I. Maturation of the Na,K-ATPase in the Endoplasmic Reticulum in Health and Disease. J Membr Biol 2021; 254:447-457. [PMID: 34114062 PMCID: PMC8192048 DOI: 10.1007/s00232-021-00184-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/08/2021] [Indexed: 12/11/2022]
Abstract
Abstract The Na,K-ATPase establishes the electrochemical gradient of cells by driving an active exchange of Na+ and K+ ions while consuming ATP. The minimal functional transporter consists of a catalytic α-subunit and a β-subunit with chaperon activity. The Na,K-ATPase also functions as a cell adhesion molecule and participates in various intracellular signaling pathways. The maturation and trafficking of the Na,K-ATPase include co- and post-translational processing of the enzyme in the endoplasmic reticulum (ER) and the Golgi apparatus and subsequent delivery to the plasma membrane (PM). The ER folding of the enzyme is considered as the rate-limiting step in the membrane delivery of the protein. It has been demonstrated that only assembled Na,K-ATPase α:β-complexes may exit the organelle, whereas unassembled, misfolded or unfolded subunits are retained in the ER and are subsequently degraded. Loss of function of the Na,K-ATPase has been associated with lung, heart, kidney and neurological disorders. Recently, it has been shown that ER dysfunction, in particular, alterations in the homeostasis of the organelle, as well as impaired ER-resident chaperone activity may impede folding of Na,K-ATPase subunits, thus decreasing the abundance and function of the enzyme at the PM. Here, we summarize our current understanding on maturation and subsequent processing of the Na,K-ATPase in the ER under physiological and pathophysiological conditions. Graphic Abstract ![]()
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Affiliation(s)
- Vitalii Kryvenko
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany.,The Cardio-Pulmonary Institute (CPI), Giessen, Germany
| | - Olga Vagin
- Department of Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA.,Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Laura A Dada
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - István Vadász
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany. .,The Cardio-Pulmonary Institute (CPI), Giessen, Germany.
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32
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Structural Basis of Substrate-Independent Phosphorylation in a P4-ATPase Lipid Flippase. J Mol Biol 2021; 433:167062. [PMID: 34023399 DOI: 10.1016/j.jmb.2021.167062] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 11/21/2022]
Abstract
P4-ATPases define a eukaryotic subfamily of the P-type ATPases, and are responsible for the transverse flip of specific lipids from the extracellular or luminal leaflet to the cytosolic leaflet of cell membranes. The enzymatic cycle of P-type ATPases is divided into autophosphorylation and dephosphorylation half-reactions. Unlike most other P-type ATPases, P4-ATPases transport their substrate during dephosphorylation only, i.e. the phosphorylation half-reaction is not associated with transport. To study the structural basis of the distinct mechanisms of P4-ATPases, we have determined cryo-EM structures of Drs2p-Cdc50p from Saccharomyces cerevisiae covering multiple intermediates of the cycle. We identify several structural motifs specific to Drs2p and P4-ATPases in general that decrease movements and flexibility of domains as compared to other P-type ATPases such as Na+/K+-ATPase or Ca2+-ATPase. These motifs include the linkers that connect the transmembrane region to the actuator (A) domain, which is responsible for dephosphorylation. Additionally, mutation of Tyr380, which interacts with conserved Asp340 of the distinct DGET dephosphorylation loop of P4-ATPases, highlights a functional role of these P4-ATPase specific motifs in the A-domain. Finally, the transmembrane (TM) domain, responsible for transport, also undergoes less extensive conformational changes, which is ensured both by a longer segment connecting TM helix 4 with the phosphorylation site, and possible stabilization by the auxiliary subunit Cdc50p. Collectively these adaptions in P4-ATPases are responsible for phosphorylation becoming transport-independent.
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33
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McDermott JP, Numata S, Blanco G. Na,K-ATPase Atp1a4 isoform is important for maintaining sperm flagellar shape. J Assist Reprod Genet 2021; 38:1493-1505. [PMID: 33977467 DOI: 10.1007/s10815-021-02087-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 01/21/2021] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The aim of this study is to investigate the mechanisms by which the testis specific Na,K-ATPase ion transport system (Atp1a4) controls sperm morphology and shape. METHODS Sperm from wild-type (WT) and Atp1a4 knockout (Atp1a4 KO) mice were analyzed morphologically, using light, transmission, and scanning electron microscopy; and functionally, applying sperm osmotic challenge and viability tests. In addition, a sperm proteomic study was performed. RESULTS Light microscopy confirmed that sperm lacking Atp1a4 present a bend at the junction of the mid- and principal piece of the flagellum. This bend had different degrees of angulation, reaching occasionally a complete flagellar retroflexion. The defect appeared in sperm collected from the cauda epididymis, but not the epididymal caput or the testis. Transmission and scanning electron microscopy revealed a dilation of the cytoplasm at the site of the bend, with fusion of the plasma membrane in overlapping segments of the flagellum. This was accompanied by defects in the axoneme and peri-axonemal structures. Sperm from Atp1a4 KO mice showed an abnormal response to hypoosmotic challenge with decreased viability, suggesting reduced capacity for volume regulation. Exposure to Triton X-100 only partially recovered the flagellar bend of Atp1a4 KO sperm, showing that factors other than osmotic regulation contribute to the flagellar defect. Interestingly, several key sperm structural proteins were expressed in lower amounts in Atp1a4 KO sperm, with no changes in their localization. CONCLUSIONS Altogether, our results show that Atp1a4 plays an important role in maintaining the proper shape of the sperm flagellum through both osmotic control and structurally related mechanisms.
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Affiliation(s)
- Jeff P McDermott
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS, 66160, USA
| | - September Numata
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS, 66160, USA
| | - Gustavo Blanco
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS, 66160, USA.
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34
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Yap JQ, Seflova J, Sweazey R, Artigas P, Robia SL. FXYD proteins and sodium pump regulatory mechanisms. J Gen Physiol 2021; 153:211866. [PMID: 33688925 PMCID: PMC7953255 DOI: 10.1085/jgp.202012633] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 02/03/2021] [Indexed: 12/12/2022] Open
Abstract
The sodium/potassium-ATPase (NKA) is the enzyme that establishes gradients of sodium and potassium across the plasma membrane. NKA activity is tightly regulated for different physiological contexts through interactions with single-span transmembrane peptides, the FXYD proteins. This diverse family of regulators has in common a domain containing a Phe-X-Tyr-Asp (FXYD) motif, two conserved glycines, and one serine residue. In humans, there are seven tissue-specific FXYD proteins that differentially modulate NKA kinetics as appropriate for each system, providing dynamic responsiveness to changing physiological conditions. Our understanding of how FXYD proteins contribute to homeostasis has benefitted from recent advances described in this review: biochemical and biophysical studies have provided insight into regulatory mechanisms, genetic models have uncovered remarkable complexity of FXYD function in integrated physiological systems, new posttranslational modifications have been identified, high-resolution structural studies have revealed new details of the regulatory interaction with NKA, and new clinical correlations have been uncovered. In this review, we address the structural determinants of diverse FXYD functions and the special roles of FXYDs in various physiological systems. We also discuss the possible roles of FXYDs in protein trafficking and regulation of non-NKA targets.
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Affiliation(s)
- John Q Yap
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL
| | - Jaroslava Seflova
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL
| | - Ryan Sweazey
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX
| | - Pablo Artigas
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL
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35
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Rinaldi DE, Ontiveros MQ, Saffioti NA, Vigil MA, Mangialavori IC, Rossi RC, Rossi JP, Espelt MV, Ferreira-Gomes MS. Epigallocatechin 3-gallate inhibits the plasma membrane Ca 2+-ATPase: effects on calcium homeostasis. Heliyon 2021; 7:e06337. [PMID: 33681501 PMCID: PMC7930289 DOI: 10.1016/j.heliyon.2021.e06337] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/16/2021] [Accepted: 02/17/2021] [Indexed: 12/27/2022] Open
Abstract
Flavonoids are natural compounds responsible for the health benefits of green tea. Some of the flavonoids present in green tea are catechins, among which are: epigallocatechin, epicatechin-3-gallate, epicatechin, catechin and epigallocatechin-3-gallate (EGCG). The latter was found to induce apoptosis, reduce reactive oxygen species, in some conditions though in others it acts as an oxidizing agent, induce cell cycle arrest, and inhibit carcinogenesis. EGCG also was found to be involved in calcium (Ca2+) homeostasis in excitable and in non-excitable cells. In this study, we investigate the effect of catechins on plasma membrane Ca2+-ATPase (PMCA), which is one of the main mechanisms that extrude Ca2+ out of the cell. Our studies comprised experiments on the isolated PMCA and on cells overexpressing the pump. Among catechins that inhibited PMCA activity, the most potent inhibitor was EGCG. EGCG inhibited PMCA activity in a reversible way favoring E1P conformation. EGCG inhibition also occurred in the presence of calmodulin, the main pump activator. Finally, the effect of EGCG on PMCA activity was studied in human embryonic kidney cells (HEK293T) that transiently overexpress hPMCA4. Results show that EGCG inhibited PMCA activity in HEK293T cells, suggesting that the effects observed on isolated PMCA occur in living cells.
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Affiliation(s)
| | | | - Nicolas A. Saffioti
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Maximiliano A. Vigil
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Irene C. Mangialavori
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Rolando C. Rossi
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Juan P. Rossi
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - María V. Espelt
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
| | - Mariela S. Ferreira-Gomes
- IQUIFIB – Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, CONICET, Junín 956, 1113 Buenos Aires, Argentina
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36
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Dabravolski SA, Isayenkov SV. Evolution of Plant Na +-P-Type ATPases: From Saline Environments to Land Colonization. PLANTS 2021; 10:plants10020221. [PMID: 33498844 PMCID: PMC7911474 DOI: 10.3390/plants10020221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 11/17/2022]
Abstract
Soil salinity is one of the major factors obstructing the growth and development of agricultural crops. Eukaryotes have two main transport systems involved in active Na+ removal: cation/H+ antiporters and Na+-P-type ATPases. Key transport proteins, Na+/K+-P-ATPases, are widely distributed among the different taxa families of pumps which are responsible for keeping cytosolic Na+ concentrations below toxic levels. Na+/K+-P-ATPases are considered to be absent in flowering plants. The data presented here are a complete inventory of P-type Na+/K+-P-ATPases in the major branches of the plant kingdom. We also attempt to elucidate the evolution of these important membrane pumps in plants in comparison with other organisms. We were able to observe the gradual replacement of the Na+-binding site to the Ca2+-binding site, starting with cyanobacteria and moving to modern land plants. Our results show that the α-subunit likely evolved from one common ancestor to bacteria, fungi, plants, and mammals, whereas the β-subunit did not evolve in green algae. In conclusion, our results strongly suggest the significant differences in the domain architecture and subunit composition of plant Na+/K+-P-ATPases depending on plant taxa and the salinity of the environment. The obtained data clarified and broadened the current views on the evolution of Na+/K+-P-ATPases. The results of this work would be helpful for further research on P-type ATPase functionality and physiological roles.
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Affiliation(s)
- Siarhei A. Dabravolski
- Department of Clinical Diagnostics, Vitebsk State Academy of Veterinary Medicine [UO VGAVM], 21002 Vitebsk, Belarus;
| | - Stanislav V. Isayenkov
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China
- Department of Plant Food Products and Biofortification, Institute of Food Biotechnology and Genomics NAS of Ukraine, 04123 Kyiv, Ukraine
- Correspondence: author:
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Orädd F, Andersson M. Tracking Membrane Protein Dynamics in Real Time. J Membr Biol 2021; 254:51-64. [PMID: 33409541 PMCID: PMC7936944 DOI: 10.1007/s00232-020-00165-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/11/2020] [Indexed: 12/14/2022]
Abstract
Abstract Membrane proteins govern critical cellular processes and are central to human health and associated disease. Understanding of membrane protein function is obscured by the vast ranges of structural dynamics—both in the spatial and time regime—displayed in the protein and surrounding membrane. The membrane lipids have emerged as allosteric modulators of membrane protein function, which further adds to the complexity. In this review, we discuss several examples of membrane dependency. A particular focus is on how molecular dynamics (MD) simulation have aided to map membrane protein dynamics and how enhanced sampling methods can enable observing the otherwise inaccessible biological time scale. Also, time-resolved X-ray scattering in solution is highlighted as a powerful tool to track membrane protein dynamics, in particular when combined with MD simulation to identify transient intermediate states. Finally, we discuss future directions of how to further develop this promising approach to determine structural dynamics of both the protein and the surrounding lipids. Graphic Abstract ![]()
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Affiliation(s)
- Fredrik Orädd
- Department of Chemistry, Umeå University, Umeå, Sweden
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Dyla M, Kjærgaard M, Poulsen H, Nissen P. Structure and Mechanism of P-Type ATPase Ion Pumps. Annu Rev Biochem 2020; 89:583-603. [PMID: 31874046 DOI: 10.1146/annurev-biochem-010611-112801] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
P-type ATPases are found in all kingdoms of life and constitute a wide range of cation transporters, primarily for H+, Na+, K+, Ca2+, and transition metal ions such as Cu(I), Zn(II), and Cd(II). They have been studied through a wide range of techniques, and research has gained very significant insight on their transport mechanism and regulation. Here, we review the structure, function, and dynamics of P2-ATPases including Ca2+-ATPases and Na,K-ATPase. We highlight mechanisms of functional transitions that are associated with ion exchange on either side of the membrane and how the functional cycle is regulated by interaction partners, autoregulatory domains, and off-cycle states. Finally, we discuss future perspectives based on emerging techniques and insights.
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Affiliation(s)
- Mateusz Dyla
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; .,Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic European Molecular Biology Laboratory (EMBL) Partnership for Molecular Medicine, 8000 Aarhus, Denmark
| | - Magnus Kjærgaard
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; .,Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic European Molecular Biology Laboratory (EMBL) Partnership for Molecular Medicine, 8000 Aarhus, Denmark
| | - Hanne Poulsen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; .,Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic European Molecular Biology Laboratory (EMBL) Partnership for Molecular Medicine, 8000 Aarhus, Denmark
| | - Poul Nissen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark; .,Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic European Molecular Biology Laboratory (EMBL) Partnership for Molecular Medicine, 8000 Aarhus, Denmark
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Osmotic and ionic regulation, and modulation by protein kinases, FXYD2 peptide and ATP of gill (Na+, K+)-ATPase activity, in the swamp ghost crab Ucides cordatus (Brachyura, Ocypodidae). Comp Biochem Physiol B Biochem Mol Biol 2020; 250:110507. [DOI: 10.1016/j.cbpb.2020.110507] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/08/2020] [Accepted: 09/14/2020] [Indexed: 11/20/2022]
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40
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Apell HJ, Roudna M. Partial Reactions of the Na,K-ATPase: Determination of Activation Energies and an Approach to Mechanism. J Membr Biol 2020; 253:631-645. [PMID: 33184678 PMCID: PMC7688194 DOI: 10.1007/s00232-020-00153-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/05/2020] [Indexed: 11/26/2022]
Abstract
Abstract Kinetic experiments were performed with preparations of kidney Na,K-ATPase in isolated membrane fragments or reconstituted in vesicles to obtain information of the activation energies under turnover conditions and for selected partial reactions of the Post-Albers pump cycle. The ion transport activities were detected with potential or conformation sensitive fluorescent dyes in steady-state or time-resolved experiments. The activation energies were derived from Arrhenius plots of measurements in the temperature range between 5 °C and 37 °C. The results were used to elaborate indications of the respective underlying rate-limiting reaction steps and allowed conclusions to be drawn about possible molecular reaction mechanisms. The observed consequent alteration between ligand-induced reaction and conformational relaxation steps when the Na,K-ATPase performs the pump cycle, together with constraints set by thermodynamic principles, provided restrictions which have to be met when mechanistic models are proposed. A model meeting such requirements is presented for discussion. Graphic Abstract ![]()
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Affiliation(s)
- Hans-Jürgen Apell
- Department of Biology, University of Konstanz, 78464, Konstanz, Germany.
| | - Milena Roudna
- Department of Biology, University of Konstanz, 78464, Konstanz, Germany
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Clarke R, Hossain K, Cao K. Physiological roles of transverse lipid asymmetry of animal membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183382. [DOI: 10.1016/j.bbamem.2020.183382] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 02/07/2023]
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Lazarov E, Hillebrand M, Schröder S, Ternka K, Hofhuis J, Ohlenbusch A, Barrantes-Freer A, Pardo LA, Fruergaard MU, Nissen P, Brockmann K, Gärtner J, Rosewich H. Comparative analysis of alternating hemiplegia of childhood and rapid-onset dystonia-parkinsonism ATP1A3 mutations reveals functional deficits, which do not correlate with disease severity. Neurobiol Dis 2020; 143:105012. [PMID: 32653672 DOI: 10.1016/j.nbd.2020.105012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/12/2020] [Accepted: 07/07/2020] [Indexed: 02/06/2023] Open
Abstract
Heterozygous mutations in the ATP1A3 gene, coding for an alpha subunit isoform (α3) of Na+/K+-ATPase, are the primary genetic cause for rapid-onset dystonia-parkinsonism (RDP) and alternating hemiplegia of childhood (AHC). Recently, cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorineural hearing loss (CAPOS), early infantile epileptic encephalopathy (EIEE), childhood rapid onset ataxia (CROA) and relapsing encephalopathy with rapid onset ataxia (RECA) extend the clinical spectrum of ATP1A3 related disorders. AHC and RDP demonstrate distinct clinical features, with AHC symptoms being generally more severe compared to RDP. Currently, it is largely unknown what determines the disease severity, and whether severity is linked to the degree of functional impairment of the α3 subunit. Here we compared the effect of twelve different RDP and AHC specific mutations on the expression and function of the α3 Na+/K+-ATPase in transfected HEK cells and oocytes. All studied mutations led to functional impairment of the pump, as reflected by lower survival rate and reduced pump current. No difference in the extent of impairment, nor in the expression level, was found between the two phenotypes, suggesting that these measures of pump dysfunction do not exclusively determine the disease severity.
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Affiliation(s)
- Elinor Lazarov
- University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Germany.
| | - Merle Hillebrand
- University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Germany.
| | - Simone Schröder
- University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Germany.
| | - Katharina Ternka
- University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Germany.
| | - Julia Hofhuis
- University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Germany.
| | - Andreas Ohlenbusch
- University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Germany.
| | | | - Luis A Pardo
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Göttingen, Germany.
| | - Marlene U Fruergaard
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Dept. Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark.
| | - Poul Nissen
- DANDRITE - Nordic EMBL Partnership for Molecular Medicine, Dept. Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark.
| | - Knut Brockmann
- University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Germany.
| | - Jutta Gärtner
- University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Germany.
| | - Hendrik Rosewich
- University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Germany.
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Moreno C, Yano S, Bezanilla F, Latorre R, Holmgren M. Transient Electrical Currents Mediated by the Na +/K +-ATPase: A Tour from Basic Biophysics to Human Diseases. Biophys J 2020; 119:236-242. [PMID: 32579966 PMCID: PMC7376075 DOI: 10.1016/j.bpj.2020.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/06/2020] [Accepted: 06/03/2020] [Indexed: 01/14/2023] Open
Abstract
The Na+/K+-ATPase is a chemical molecular machine responsible for the movement of Na+ and K+ ions across the cell membrane. These ions are moved against their electrochemical gradients, so the protein uses the free energy of ATP hydrolysis to transport them. In fact, the Na+/K+-ATPase is the single largest consumer of energy in most cells. In each pump cycle, the protein sequentially exports 3Na+ out of the cell, then imports 2K+ into the cell at an approximate rate of 200 cycles/s. In each half cycle of the transport process, there is a state in which ions are stably trapped within the permeation pathway of the protein by internal and external gates in their closed states. These gates are required to open alternately; otherwise, passive ion diffusion would be a wasteful end of the cell's energy. Once one of these gates open, ions diffuse from their binding sites to the accessible milieu, which involves moving through part of the electrical field across the membrane. Consequently, ions generate transient electrical currents first discovered more than 30 years ago. They have been studied in a variety of preparations, including native and heterologous expression systems. Here, we review three decades' worth of work using these transient electrical signals to understand the kinetic transitions of the movement of Na+ and K+ ions through the Na+/K+-ATPase and propose the significance that this work might have to the understanding of the dysfunction of human pump orthologs responsible for some newly discovered neurological pathologies.
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Affiliation(s)
- Cristina Moreno
- Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Sho Yano
- Medical Genetics and Genomic Medicine Training Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Francisco Bezanilla
- Department of Biochemistry and Molecular Biology, University of Chicago, Gordon Center for Integrative Sciences, Chicago, Illinois
| | - Ramon Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Miguel Holmgren
- Molecular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.
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Moraes CM, Lucena MN, Garçon DP, Pinto MR, Fabri LM, Faleiros RO, Fontes CFL, McNamara JC, Leone FA. Biochemical Characterization and Allosteric Modulation by Magnesium of (Na +, K +)-ATPase Activity in the Gills of the Red Mangrove Crab Goniopsis cruentata (Brachyura, Grapsidae). J Membr Biol 2020; 253:229-245. [PMID: 32440867 DOI: 10.1007/s00232-020-00120-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 05/02/2020] [Indexed: 11/26/2022]
Abstract
We provide a kinetic characterization of (Na+, K+)-ATPase activity in a posterior gill microsomal fraction from the grapsid crab Goniopsis cruentata. (Na+, K+)-ATPase activity constitutes 95% of total ATPase activity, and sucrose density centrifugation reveals an ATPase activity peak between 25 and 35% sucrose, distributed into two, partially separated protein fractions. The (Na+, K+)-ATPase α-subunit is localized throughout the ionocyte cytoplasm and has an Mr of ≈ 10 kDa and hydrolyzes ATP obeying cooperative kinetics. Low (VM = 186.0 ± 9.3 nmol Pi min-1 mg-1 protein and K0.5 = 0.085 ± 0.004 mmol L-1) and high (VM = 153.4 ± 7.7 nmol Pi min-1 mg-1 protein and K0.5 = 0.013 ± 0.0006 mmol L-1) affinity ATP binding sites were characterized. At low ATP concentrations, excess Mg2+ stimulates the enzyme, triggering exposure of a high-affinity binding site that accounts for 50% of (Na+, K+)-ATPase activity. Stimulation by Mg2+ (VM = 425.9 ± 25.5 nmol Pi min-1 mg-1 protein, K0.5 = 0.16 ± 0.01 mmol L-1), K+ (VM = 485.3 ± 24.3 nmol Pi min-1 mg-1 protein, K0.5 = 0.9 ± 0.05 mmol L-1), Na+ (VM = 425.0 ± 23.4 nmol Pi min-1 mg-1 protein, K0.5 = 5.1 ± 0.3 mmol L-1) and NH4+ (VM = 497.9 ± 24.9 nmol Pi min-1 mg-1 protein, K0.5 = 9.7 ± 0.5 mmol L-1) obeys cooperative kinetics. Ouabain inhibits up to 95% of ATPase activity with KI = 196.6 ± 9.8 µmol L-1. This first kinetic characterization of the gill (Na+, K+)-ATPase in Goniopsis cruentata enables better comprehension of the biochemical underpinnings of osmoregulatory ability in this semi-terrestrial mangrove crab.
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Affiliation(s)
- Cintya M Moraes
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14040-901, Brazil
| | - Malson N Lucena
- Instituto de Biociências, Universidade Federal do Mato Grosso do Sul, Campo Grande, MS, Brazil
| | | | - Marcelo R Pinto
- Laboratório de Biopatologia e Biologia Molecular Universidade Uberaba, Uberaba, MG, Brazil
| | - Leonardo M Fabri
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14040-901, Brazil
| | - Rogério O Faleiros
- Departamento de Ciências Agrárias e Biológicas, Universidade Federal do Espírito Santo, São Mateus, ES, Brazil
| | - Carlos F L Fontes
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - John C McNamara
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
- Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, SP, Brazil
| | - Francisco A Leone
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14040-901, Brazil.
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45
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Kumari J, Rathore MS. Na+/K+-ATPase a Primary Membrane Transporter: An Overview and Recent Advances with Special Reference to Algae. J Membr Biol 2020; 253:191-204. [DOI: 10.1007/s00232-020-00119-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 05/02/2020] [Indexed: 12/16/2022]
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Aperia A, Brismar H, Uhlén P. Mending Fences: Na,K-ATPase signaling via Ca 2+ in the maintenance of epithelium integrity. Cell Calcium 2020; 88:102210. [PMID: 32380435 DOI: 10.1016/j.ceca.2020.102210] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/18/2022]
Abstract
Na,K-ATPase is a ubiquitous multifunctional protein that acts both as an ion pump and as a signal transducer. The signaling function is activated by ouabain in non-toxic concentrations. In epithelial cells the ouabain-bound Na,K-ATPase connects with the inositol 1,4,5-trisphosphate receptor via a short linear motif to activate low frequency Ca2+ oscillations. Within a couple of minutes this ouabain mediated signal has resulted in phosphorylation or dephosphorylation of 2580 phospho-sites. Proteins that control cell proliferation and cell adhesion and calmodulin regulated proteins are enriched among the ouabain phosphor-regulated proteins. The inositol 1,4,5-trisphosphate receptor and the stromal interaction molecule, which are both essential for the initiation of Ca2+ oscillations, belong to the ouabain phosphor-regulated proteins. Downstream effects of the ouabain-evoked Ca2+ signal in epithelial cells include interference with the intrinsic mitochondrial apoptotic process and stimulation of embryonic growth processes. The dual function of Na,K-ATPase as an ion pump and a signal transducer is now well established and evaluation of the physiological and pathophysiological consequences of this universal signal emerges as an urgent topic for future studies.
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Affiliation(s)
- Anita Aperia
- Science for Life Laboratory, Dept of Women's and Children's Health, Karolinska Institutet, Sweden
| | - Hjalmar Brismar
- Science for Life Laboratory, Dept of Women's and Children's Health, Karolinska Institutet, Sweden; Science for Life Laboratory, Dept of Applied Physics, KTH Royal Institute of Technology, Sweden.
| | - Per Uhlén
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
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47
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Hossain KR, Li X, Zhang T, Paula S, Cornelius F, Clarke RJ. Polarity of the ATP binding site of the Na +,K +-ATPase, gastric H +,K +-ATPase and sarcoplasmic reticulum Ca 2+-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183138. [PMID: 31790695 DOI: 10.1016/j.bbamem.2019.183138] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/15/2019] [Accepted: 11/27/2019] [Indexed: 11/18/2022]
Abstract
A fluorescence ratiometric method utilizing the probe eosin Y is presented for estimating the ATP binding site polarity of P-type ATPases in different conformational states. The method has been calibrated by measurements in a series of alcohols and tested using complexation of eosin Y with methyl-β-cyclodextrin. The results obtained with the Na+,K+-, H+,K+- and sarcoplasmic reticulum Ca2+-ATPases indicate that the ATP binding site, to which eosin is known to bind, is significantly more polar in the case of the Na+,K+- and H+,K+-ATPases compared to the Ca2+-ATPase. This result was found to be consistent with docking calculations of eosin with the E2 conformational state of the Na+,K+-ATPase and the Ca2+-ATPase. Fluorescence experiments showed that eosin binds significantly more strongly to the E1 conformation of the Na+,K+-ATPase than the E2 conformation, but in the case of the Ca2+-ATPase both fluorescence experiments and docking calculations showed no significant difference in binding affinity between the two conformations. This result could be due to the fact that, in contrast to the Na+,K+- and H+,K+-ATPases, the E2-E1 transition of the Ca2+-ATPase does not involve the movement of a lysine-rich N-terminal tail which may affect the overall enzyme conformation. Consistent with this hypothesis, the eosin affinity of the E1 conformation of the Na+,K+-ATPase was significantly reduced after N-terminal truncation. It is suggested that changes in conformational entropy of the N-terminal tail of the Na+, K+- and the H+,K+-ATPases during the E2-E1 transition could affect the thermodynamic stability of the E1 conformation and hence its ATP binding affinity.
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Affiliation(s)
- K R Hossain
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
| | - X Li
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
| | - T Zhang
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
| | - S Paula
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
| | - F Cornelius
- Department of Biomedicine, University of Aarhus, DK-8000 Aarhus C, Denmark
| | - R J Clarke
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, Sydney, NSW 2006, Australia.
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Burat B, Faucher Q, Čechová P, Arnion H, Di Meo F, Sauvage F, Marquet P, Essig M. Cyclosporine A inhibits MRTF-SRF signaling through Na +/K + ATPase inhibition and actin remodeling. FASEB Bioadv 2019; 1:561-578. [PMID: 32123851 PMCID: PMC6996406 DOI: 10.1096/fba.2019-00027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 03/22/2019] [Accepted: 07/25/2019] [Indexed: 01/07/2023] Open
Abstract
Calcineurin inhibitors (CNI) are the pillars of immunosuppression in transplantation. However, they display a potent nephrotoxicity whose mechanisms remained widely unsolved. We used an untargeted quantitative proteomic approach (iTRAQ technology) to highlight new targets of CNI in renal proximal tubular cells (RPTCs). CNI-treated RPTCs proteome displayed an over-representation of actin-binding proteins with a CNI-specific expression profile. Cyclosporine A (CsA) induced F-actin remodeling and depolymerization, decreased F-actin-stabilizing, polymerization-promoting cofilin (CFL) oligomers, and inhibited the G-actin-regulated serum response factor (SRF) pathway. Inhibition of CFL canonical phosphorylation pathway reproduced CsA effects; however, S3-R, an analogue of the phosphorylation site of CFL prevented the effects of CsA which suggests that CsA acted independently from the canonical CFL regulation. CFL is known to be regulated by the Na+/K+-ATPase. Molecular docking calculations identified two inhibiting sites of CsA on Na+/K+-ATPase and a 23% decrease in Na+/K+-ATPase activity of RPTCs was observed with CsA. Ouabain, a specific inhibitor of Na+/K+-ATPase also reproduced CsA effects on actin organization and SRF activity. Altogether, these results described a new original pathway explaining CsA nephrotoxicity.
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Affiliation(s)
- Bastien Burat
- Centre for Biology & Health Research, UMR INSERM 1248 IPPRIT (Individual Profiling and Prevention of RIsks in Transplantation)Limoges UniversityLimogesFrance
| | - Quentin Faucher
- Centre for Biology & Health Research, UMR INSERM 1248 IPPRIT (Individual Profiling and Prevention of RIsks in Transplantation)Limoges UniversityLimogesFrance
| | - Petra Čechová
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of SciencePalacký University OlomoucOlomoucCzech Republic
- Department of Physical Chemistry, Regional Centre of Advanced Technologies and Materials, Faculty of SciencePalacký University OlomoucOlomoucCzech Republic
| | - Hélène Arnion
- Centre for Biology & Health Research, UMR INSERM 1248 IPPRIT (Individual Profiling and Prevention of RIsks in Transplantation)Limoges UniversityLimogesFrance
| | - Florent Di Meo
- Centre for Biology & Health Research, UMR INSERM 1248 IPPRIT (Individual Profiling and Prevention of RIsks in Transplantation)Limoges UniversityLimogesFrance
| | - François‐Ludovic Sauvage
- Centre for Biology & Health Research, UMR INSERM 1248 IPPRIT (Individual Profiling and Prevention of RIsks in Transplantation)Limoges UniversityLimogesFrance
| | - Pierre Marquet
- Centre for Biology & Health Research, UMR INSERM 1248 IPPRIT (Individual Profiling and Prevention of RIsks in Transplantation)Limoges UniversityLimogesFrance
- Department of Pharmacology and ToxicologyLimoges University HospitalLimogesFrance
| | - Marie Essig
- Centre for Biology & Health Research, UMR INSERM 1248 IPPRIT (Individual Profiling and Prevention of RIsks in Transplantation)Limoges UniversityLimogesFrance
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Sampedro Castañeda M, Zanoteli E, Scalco RS, Scaramuzzi V, Marques Caldas V, Conti Reed U, da Silva AMS, O'Callaghan B, Phadke R, Bugiardini E, Sud R, McCall S, Hanna MG, Poulsen H, Männikkö R, Matthews E. A novel ATP1A2 mutation in a patient with hypokalaemic periodic paralysis and CNS symptoms. Brain 2019; 141:3308-3318. [PMID: 30423015 PMCID: PMC6262219 DOI: 10.1093/brain/awy283] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 09/25/2018] [Indexed: 01/26/2023] Open
Abstract
Hypokalaemic periodic paralysis is a rare genetic neuromuscular disease characterized by episodes of skeletal muscle paralysis associated with low serum potassium. Muscle fibre inexcitability during attacks of paralysis is due to an aberrant depolarizing leak current through mutant voltage sensing domains of either the sarcolemmal voltage-gated calcium or sodium channel. We report a child with hypokalaemic periodic paralysis and CNS involvement, including seizures, but without mutations in the known periodic paralysis genes. We identified a novel heterozygous de novo missense mutation in the ATP1A2 gene encoding the α2 subunit of the Na+/K+-ATPase that is abundantly expressed in skeletal muscle and in brain astrocytes. Pump activity is crucial for Na+ and K+ homeostasis following sustained muscle or neuronal activity and its dysfunction is linked to the CNS disorders hemiplegic migraine and alternating hemiplegia of childhood, but muscle dysfunction has not been reported. Electrophysiological measurements of mutant pump activity in Xenopus oocytes revealed lower turnover rates in physiological extracellular K+ and an anomalous inward leak current in hypokalaemic conditions, predicted to lead to muscle depolarization. Our data provide important evidence supporting a leak current as the major pathomechanism underlying hypokalaemic periodic paralysis and indicate ATP1A2 as a new hypokalaemic periodic paralysis gene.
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Affiliation(s)
- Marisol Sampedro Castañeda
- MRC Centre for Neuromuscular Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Edmar Zanoteli
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - Renata S Scalco
- MRC Centre for Neuromuscular Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Vinicius Scaramuzzi
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - Vitor Marques Caldas
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - Umbertina Conti Reed
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | | | - Benjamin O'Callaghan
- MRC Centre for Neuromuscular Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Rahul Phadke
- Division of Neuropathology, UCL Institute of Neurology, London, UK
| | - Enrico Bugiardini
- MRC Centre for Neuromuscular Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Richa Sud
- Neurogenetics Unit, UCL Institute of Neurology, Queen Square, London, UK
| | - Samuel McCall
- Neurogenetics Unit, UCL Institute of Neurology, Queen Square, London, UK
| | - Michael G Hanna
- MRC Centre for Neuromuscular Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Hanne Poulsen
- DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, DK-8000 Aarhus, Denmark
| | - Roope Männikkö
- MRC Centre for Neuromuscular Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Emma Matthews
- MRC Centre for Neuromuscular Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
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50
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Panizza E, Zhang L, Fontana JM, Hamada K, Svensson D, Akkuratov EE, Scott L, Mikoshiba K, Brismar H, Lehtiö J, Aperia A. Ouabain-regulated phosphoproteome reveals molecular mechanisms for Na +, K +-ATPase control of cell adhesion, proliferation, and survival. FASEB J 2019; 33:10193-10206. [PMID: 31199885 PMCID: PMC6704450 DOI: 10.1096/fj.201900445r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ion pump Na+, K+-ATPase (NKA) is a receptor for the cardiotonic steroid ouabain. Subsaturating concentration of ouabain triggers intracellular calcium oscillations, stimulates cell proliferation and adhesion, and protects from apoptosis. However, it is controversial whether ouabain-bound NKA is considered a signal transducer. To address this question, we performed a global analysis of protein phosphorylation in COS-7 cells, identifying 2580 regulated phosphorylation events on 1242 proteins upon 10- and 20-min treatment with ouabain. Regulated phosphorylated proteins include the inositol triphosphate receptor and stromal interaction molecule, which are essential for initiating calcium oscillations. Hierarchical clustering revealed that ouabain triggers a structured phosphorylation response that occurs in a well-defined, time-dependent manner and affects specific cellular processes, including cell proliferation and cell-cell junctions. We additionally identify regulation of the phosphorylation of several calcium and calmodulin-dependent protein kinases (CAMKs), including 2 sites of CAMK type II-γ (CAMK2G), a protein known to regulate apoptosis. To verify the significance of this result, CAMK2G was knocked down in primary kidney cells. CAMK2G knockdown impaired ouabain-dependent protection from apoptosis upon treatment with high glucose or serum deprivation. In conclusion, we establish NKA as the coordinator of a broad, tightly regulated phosphorylation response in cells and define CAMK2G as a downstream effector of NKA.-Panizza, E., Zhang, L., Fontana, J. M., Hamada, K., Svensson, D., Akkuratov, E. E., Scott, L., Mikoshiba, K., Brismar, H., Lehtiö, J., Aperia, A. Ouabain-regulated phosphoproteome reveals molecular mechanisms for Na+, K+-ATPase control of cell adhesion, proliferation, and survival.
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Affiliation(s)
- Elena Panizza
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institutet, Solna, Sweden
| | - Liang Zhang
- Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden
| | - Jacopo Maria Fontana
- Department of Applied Physics, Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Kozo Hamada
- Laboratory for Developmental Neurobiology, Brain Science Institute, Riken, Saitama, Japan
| | - Daniel Svensson
- Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden
| | - Evgeny E Akkuratov
- Department of Applied Physics, Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Lena Scott
- Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, Brain Science Institute, Riken, Saitama, Japan
| | - Hjalmar Brismar
- Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden.,Department of Applied Physics, Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Janne Lehtiö
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institutet, Solna, Sweden
| | - Anita Aperia
- Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden
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