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Yanagisawa S, Bukhari ZA, Parra KJ, Frasch WD. Eukaryotic yeast V 1-ATPase rotary mechanism insights revealed by high-resolution single-molecule studies. Front Mol Biosci 2024; 11:1269040. [PMID: 38567099 PMCID: PMC10985318 DOI: 10.3389/fmolb.2024.1269040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 02/07/2024] [Indexed: 04/04/2024] Open
Abstract
Vacuolar ATP-dependent proton pumps (V-ATPases) belong to a super-family of rotary ATPases and ATP synthases. The V1 complex consumes ATP to drive rotation of a central rotor that pumps protons across membranes via the Vo complex. Eukaryotic V-ATPases are regulated by reversible disassembly of subunit C, V1 without C, and VO. ATP hydrolysis is thought to generate an unknown rotary state that initiates regulated disassembly. Dissociated V1 is inhibited by subunit H that traps it in a specific rotational position. Here, we report the first single-molecule studies with high resolution of time and rotational position of Saccharomyces cerevisiae V1-ATPase lacking subunits H and C (V1ΔHC), which resolves previously elusive dwells and angular velocity changes. Rotation occurred in 120° power strokes separated by dwells comparable to catalytic dwells observed in other rotary ATPases. However, unique V1ΔHC rotational features included: 1) faltering power stroke rotation during the first 60°; 2) a dwell often occurring ∼45° after the catalytic dwell, which did not increase in duration at limiting MgATP; 3) a second dwell, ∼2-fold longer occurring 112° that increased in duration and occurrence at limiting MgATP; 4) limiting MgATP-dependent decreases in power stroke angular velocity where dwells were not observed. The results presented here are consistent with MgATP binding to the empty catalytic site at 112° and MgADP released at ∼45°, and provide important new insight concerning the molecular basis for the differences in rotary positions of substrate binding and product release between V-type and F-type ATPases.
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Affiliation(s)
- Seiga Yanagisawa
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Zain A. Bukhari
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Karlett J. Parra
- Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Wayne D. Frasch
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
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2
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Lévêque C, Maulet Y, Wang Q, Rame M, Rodriguez L, Mochida S, Sangiardi M, Youssouf F, Iborra C, Seagar M, Vitale N, El Far O. A Role for the V0 Sector of the V-ATPase in Neuroexocytosis: Exogenous V0d Blocks Complexin and SNARE Interactions with V0c. Cells 2023; 12:cells12050750. [PMID: 36899886 PMCID: PMC10001230 DOI: 10.3390/cells12050750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/03/2023] Open
Abstract
V-ATPase is an important factor in synaptic vesicle acidification and is implicated in synaptic transmission. Rotation in the extra-membranous V1 sector drives proton transfer through the membrane-embedded multi-subunit V0 sector of the V-ATPase. Intra-vesicular protons are then used to drive neurotransmitter uptake by synaptic vesicles. V0a and V0c, two membrane subunits of the V0 sector, have been shown to interact with SNARE proteins, and their photo-inactivation rapidly impairs synaptic transmission. V0d, a soluble subunit of the V0 sector strongly interacts with its membrane-embedded subunits and is crucial for the canonic proton transfer activity of the V-ATPase. Our investigations show that the loop 1.2 of V0c interacts with complexin, a major partner of the SNARE machinery and that V0d1 binding to V0c inhibits this interaction, as well as V0c association with SNARE complex. The injection of recombinant V0d1 in rat superior cervical ganglion neurons rapidly reduced neurotransmission. In chromaffin cells, V0d1 overexpression and V0c silencing modified in a comparable manner several parameters of unitary exocytotic events. Our data suggest that V0c subunit promotes exocytosis via interactions with complexin and SNAREs and that this activity can be antagonized by exogenous V0d.
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Affiliation(s)
- Christian Lévêque
- INSERM UMR_S 1072, 13015 Marseille, France
- Aix-Marseille Université, 13015 Marseille, France
| | - Yves Maulet
- INSERM UMR_S 1072, 13015 Marseille, France
- Aix-Marseille Université, 13015 Marseille, France
| | - Qili Wang
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, 67000 Strasbourg, France
| | - Marion Rame
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, 67000 Strasbourg, France
| | - Léa Rodriguez
- INSERM UMR_S 1072, 13015 Marseille, France
- Aix-Marseille Université, 13015 Marseille, France
| | - Sumiko Mochida
- Department of Physiology, Tokyo Medical University, Tokyo 160-8402, Japan
| | - Marion Sangiardi
- INSERM UMR_S 1072, 13015 Marseille, France
- Aix-Marseille Université, 13015 Marseille, France
| | - Fahamoe Youssouf
- INSERM UMR_S 1072, 13015 Marseille, France
- Aix-Marseille Université, 13015 Marseille, France
| | - Cécile Iborra
- INSERM UMR_S 1072, 13015 Marseille, France
- Aix-Marseille Université, 13015 Marseille, France
| | - Michael Seagar
- INSERM UMR_S 1072, 13015 Marseille, France
- Aix-Marseille Université, 13015 Marseille, France
| | - Nicolas Vitale
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, 67000 Strasbourg, France
- Correspondence: (N.V.); or (O.E.F.); Tel.: +33-(0)3-8845-6712 (N.V.); +33-(0)4-9169-8860 (O.E.F.)
| | - Oussama El Far
- INSERM UMR_S 1072, 13015 Marseille, France
- Aix-Marseille Université, 13015 Marseille, France
- Correspondence: (N.V.); or (O.E.F.); Tel.: +33-(0)3-8845-6712 (N.V.); +33-(0)4-9169-8860 (O.E.F.)
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3
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Direct observation of stepping rotation of V-ATPase reveals rigid component in coupling between V o and V 1 motors. Proc Natl Acad Sci U S A 2022; 119:e2210204119. [PMID: 36215468 PMCID: PMC9586324 DOI: 10.1073/pnas.2210204119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
V-ATPases are ion pumps consisting of two rotary motor proteins, Vo and V1, that actively transport ions across the cell membrane using the chemical energy of ATP. To understand how V-ATPases transduce the energy in the presence of a structural symmetry mismatch between Vo and V1, we simultaneously visualized the rotational pauses and forward and backward steps of Vo and V1 coupled with ion transport and ATP hydrolysis reactions, respectively. Our results suggest that V-ATPases with multiple peripheral stalks are more rigidly coupled than F-ATPases that have only one peripheral stalk and work as ATP synthases. Our high-speed/high-precision single-molecule imaging of rotary ATPases in action will pave the way for a comprehensive understanding of their energy transduction mechanisms. V-ATPases are rotary motor proteins that convert the chemical energy of ATP into the electrochemical potential of ions across cell membranes. V-ATPases consist of two rotary motors, Vo and V1, and Enterococcus hirae V-ATPase (EhVoV1) actively transports Na+ in Vo (EhVo) by using torque generated by ATP hydrolysis in V1 (EhV1). Here, we observed ATP-driven stepping rotation of detergent-solubilized EhVoV1 wild-type, aE634A, and BR350K mutants under various Na+ and ATP concentrations ([Na+] and [ATP], respectively) by using a 40-nm gold nanoparticle as a low-load probe. When [Na+] was low and [ATP] was high, under the condition that only Na+ binding to EhVo is rate limiting, wild-type and aE634A exhibited 10 pausing positions reflecting 10-fold symmetry of the EhVo rotor and almost no backward steps. Duration time before the forward steps was inversely proportional to [Na+], confirming that Na+ binding triggers the steps. When both [ATP] and [Na+] were low, under the condition that both Na+ and ATP bindings are rate limiting, aE634A exhibited 13 pausing positions reflecting 10- and 3-fold symmetries of EhVo and EhV1, respectively. The distribution of duration time before the forward step was fitted well by the sum of two exponential decay functions with distinct time constants. Furthermore, occasional backward steps smaller than 36° were observed. Small backward steps were also observed during three long ATP cleavage pauses of BR350K. These results indicate that EhVo and EhV1 do not share pausing positions, Na+ and ATP bindings occur at different angles, and the coupling between EhVo and EhV1 has a rigid component.
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Structural snapshots of V/A-ATPase reveal the rotary catalytic mechanism of rotary ATPases. Nat Commun 2022; 13:1213. [PMID: 35260556 PMCID: PMC8904598 DOI: 10.1038/s41467-022-28832-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/01/2022] [Indexed: 12/13/2022] Open
Abstract
V/A-ATPase is a motor protein that shares a common rotary catalytic mechanism with FoF1 ATP synthase. When powered by ATP hydrolysis, the V1 domain rotates the central rotor against the A3B3 hexamer, composed of three catalytic AB dimers adopting different conformations (ABopen, ABsemi, and ABclosed). Here, we report the atomic models of 18 catalytic intermediates of the V1 domain of V/A-ATPase under different reaction conditions, determined by single particle cryo-EM. The models reveal that the rotor does not rotate immediately after binding of ATP to the V1. Instead, three events proceed simultaneously with the 120˚ rotation of the shaft: hydrolysis of ATP in ABsemi, zipper movement in ABopen by the binding ATP, and unzipper movement in ABclosed with release of both ADP and Pi. This indicates the unidirectional rotation of V/A-ATPase by a ratchet-like mechanism owing to ATP hydrolysis in ABsemi, rather than the power stroke model proposed previously for F1-ATPase. The rotary ATPases use a rotary catalytic mechanism to drive transmembrane proton movement powered by ATP hydrolysis. Here, the authors report a collection of V/A-ATPase V1 domain structures, providing insights into rotary mechanism of the enzyme and potentially other rotary motor proteins driven by ATP hydrolysis.
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Popova LG, Matalin DA, Balnokin YV. Electrogenesis in Plasma Membrane Fraction of Halotolerant Microalga Dunaliella maritima and Effects of N,N'-Dicyclohexylcarbodiimide. BIOCHEMISTRY (MOSCOW) 2021; 85:930-937. [PMID: 33045953 DOI: 10.1134/s0006297920080088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The effects of N,N'-dicyclohexylcarbodiimide (DCCD), non-specific inhibitor of various transport systems functioning in biological membranes, on Na+-transporting P-type ATPase of the green halotolerant microalga Dunaliella maritima were studied in the experiments with vesicular plasma membranes isolated from the alga cells. The effects of DCCD on electrogenic/ion transport function of the enzyme and its ATP hydrolase activity were investigated. Electrogenic/ion transport function of the enzyme was recorded as a Na+-dependent generation of electric potential on the vesicle membranes with the help of the potential-sensitive probe oxonol VI. It was found that unlike many other ion-transporting ATPases, the Na+-ATPase of D. maritima is insensitive to DCCD. This agent did not inhibit either ATP hydrolysis catalyzed by this enzyme or its transport activity. At the same time DCCD affected the ability of the vesicle membranes to maintain electric potential generated by the D. maritima Na+-ATPase. The observed effects can be explained based on the assumption that DCCD interacts with the Na+/H+ antiporter in the plasma membrane of D. maritima.
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Affiliation(s)
- L G Popova
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, 127276, Russia.
| | - D A Matalin
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, 127276, Russia
| | - Yu V Balnokin
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, 127276, Russia
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6
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Kishikawa JI, Nakanishi A, Furuta A, Kato T, Namba K, Tamakoshi M, Mitsuoka K, Yokoyama K. Mechanical inhibition of isolated V o from V/A-ATPase for proton conductance. eLife 2020; 9:56862. [PMID: 32639230 PMCID: PMC7367684 DOI: 10.7554/elife.56862] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 07/07/2020] [Indexed: 12/18/2022] Open
Abstract
V-ATPase is an energy converting enzyme, coupling ATP hydrolysis/synthesis in the hydrophilic V1 domain, with proton flow through the Vo membrane domain, via rotation of the central rotor complex relative to the surrounding stator apparatus. Upon dissociation from the V1 domain, the Vo domain of the eukaryotic V-ATPase can adopt a physiologically relevant auto-inhibited form in which proton conductance through the Vo domain is prevented, however the molecular mechanism of this inhibition is not fully understood. Using cryo-electron microscopy, we determined the structure of both the holo V/A-ATPase and isolated Vo at near-atomic resolution, respectively. These structures clarify how the isolated Vo domain adopts the auto-inhibited form and how the holo complex prevents formation of the inhibited Vo form.
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Affiliation(s)
- Jun-Ichi Kishikawa
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan.,Institute for Protein Research, Osaka University, Suita, Japan
| | - Atsuko Nakanishi
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan.,Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Research Center for Ultra-High Voltage Electron Microscopy, Mihogaoka, Osaka, Japan
| | - Aya Furuta
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan
| | - Takayuki Kato
- Institute for Protein Research, Osaka University, Suita, Japan.,Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,RIKEN Center for Biosystems Dynamics Research and SPring-8 Center, Suita, Japan.,JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, Suita, Japan
| | - Masatada Tamakoshi
- Department of Molecular Biology, Tokyo University of Pharmacy and Life Sciences, Horinouchi, Hachioji, Tokyo, Japan
| | - Kaoru Mitsuoka
- Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Research Center for Ultra-High Voltage Electron Microscopy, Mihogaoka, Osaka, Japan
| | - Ken Yokoyama
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kyoto, Japan
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7
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Nanoparticle-Mediated Therapeutic Application for Modulation of Lysosomal Ion Channels and Functions. Pharmaceutics 2020; 12:pharmaceutics12030217. [PMID: 32131531 PMCID: PMC7150957 DOI: 10.3390/pharmaceutics12030217] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 02/07/2023] Open
Abstract
Applications of nanoparticles in various fields have been addressed. Nanomaterials serve as carriers for transporting conventional drugs or proteins through lysosomes to various cellular targets. The basic function of lysosomes is to trigger degradation of proteins and lipids. Understanding of lysosomal functions is essential for enhancing the efficacy of nanoparticles-mediated therapy and reducing the malfunctions of cellular metabolism. The lysosomal function is modulated by the movement of ions through various ion channels. Thus, in this review, we have focused on the recruited ion channels for lysosomal function, to understand the lysosomal modulation through the nanoparticles and its applications. In the future, lysosomal channels-based targets will expand the therapeutic application of nanoparticles-associated drugs.
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8
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Krah A, Marzinek JK, Bond PJ. Insights into water accessible pathways and the inactivation mechanism of proton translocation by the membrane-embedded domain of V-type ATPases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1004-1010. [DOI: 10.1016/j.bbamem.2019.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 01/29/2019] [Accepted: 02/27/2019] [Indexed: 01/25/2023]
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9
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Duan X, Yang S, Zhang L, Yang T. V-ATPases and osteoclasts: ambiguous future of V-ATPases inhibitors in osteoporosis. Theranostics 2018; 8:5379-5399. [PMID: 30555553 PMCID: PMC6276090 DOI: 10.7150/thno.28391] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) play a critical role in regulating extracellular acidification of osteoclasts and bone resorption. The deficiencies of subunit a3 and d2 of V-ATPases result in increased bone density in humans and mice. One of the traditional drug design strategies in treating osteoporosis is the use of subunit a3 inhibitor. Recent findings connect subunits H and G1 with decreased bone density. Given the controversial effects of ATPase subunits on bone density, there is a critical need to review the subunits of V-ATPase in osteoclasts and their functions in regulating osteoclasts and bone remodeling. In this review, we comprehensively address the following areas: information about all V-ATPase subunits and their isoforms; summary of V-ATPase subunits associated with human genetic diseases; V-ATPase subunits and osteopetrosis/osteoporosis; screening of all V-ATPase subunits variants in GEFOS data and in-house data; spectrum of V-ATPase subunits during osteoclastogenesis; direct and indirect roles of subunits of V-ATPases in osteoclasts; V-ATPase-associated signaling pathways in osteoclasts; interactions among V-ATPase subunits in osteoclasts; osteoclast-specific V-ATPase inhibitors; perspective of future inhibitors or activators targeting V-ATPase subunits in the treatment of osteoporosis.
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Affiliation(s)
- Xiaohong Duan
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Shaoqing Yang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Lei Zhang
- Center for Genetic Epidemiology and Genomics, School of Public Health, Medical College of Soochow University, 199 Renai Road, Suzhou, Jiangsu, P. R. China
| | - Tielin Yang
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, 28 West Xianning Road, Xi'an 710049, People's Republic of China
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10
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Chromophore-Assisted Light Inactivation of the V-ATPase V0c Subunit Inhibits Neurotransmitter Release Downstream of Synaptic Vesicle Acidification. Mol Neurobiol 2018; 56:3591-3602. [PMID: 30155790 DOI: 10.1007/s12035-018-1324-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/17/2018] [Indexed: 10/28/2022]
Abstract
Synaptic vesicle proton V-ATPase is an essential component in synaptic vesicle function. Active acidification of synaptic vesicles, triggered by the V-ATPase, is necessary for neurotransmitter storage. Independently from its proton transport activity, an additional important function of the membrane-embedded sector of the V-ATPase has been uncovered over recent years. Subunits a and c of the membrane sector of this multi-molecular complex have been shown to interact with SNARE proteins and to be involved in modulating neurotransmitter release. The c-subunit interacts with the v-SNARE VAMP2 and facilitates neurotransmission. In this study, we used chromophore-assisted light inactivation and monitored the consequences on neurotransmission on line in CA3 pyramidal neurons. We show that V-ATPase c-subunit V0c is a key element in modulating neurotransmission and that its specific inactivation rapidly inhibited neurotransmission.
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11
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Cooperative electrogenic proton transport pathways in the plasma membrane of the proton-secreting osteoclast. Pflugers Arch 2018; 470:851-866. [PMID: 29550927 DOI: 10.1007/s00424-018-2137-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 02/13/2018] [Accepted: 03/06/2018] [Indexed: 02/05/2023]
Abstract
A proton is a ubiquitous signaling ion. Many transmembrane H+ transport pathways either maintain pH homeostasis or generate acidic compartments. The osteoclast is a bone-resorbing cell, which degrades bone tissues by secreting protons and lysosomal enzymes into the resorption pit. The plasma membrane facing bone tissue (ruffled border), generated partly by fusion of lysosomes, may mimic H+ flux mechanisms regulating acidic vesicles. We identified three electrogenic H+-fluxes in osteoclast plasma membranes-a vacuolar H+-ATPase (V-ATPase), a voltage-gated proton channel (Hv channel) and an acid-inducible H+-leak-whose electrophysiological profiles and regulation mechanisms differed. V-ATPase and Hv channel, both may have intracellular reservoirs, but the recruitment/internalization is regulated independently. V-ATPase mediates active H+ efflux, acidifying the resorption pit, while acid-inducible H+ leak, activated at an extracellular pH < 5.5, diminishes pit acidification, possibly to protect bone from excess degradation. The two-way H+ flux mechanisms in opposite directions may have advantages in fine regulation of pit pH. Hv channel mediates passive H+ efflux. Although its working ranges are limited, the amount of H+ extrusion is 100 times larger than those of the V-ATPase and may support reactive oxygen species production during osteoclastogenesis. Extracellular Ca2+, H+ and inorganic phosphate, which accumulate in the resorption pit, will either stimulate or inhibit these H+ fluxes. Skeletal integration is disrupted by too much or too less of bone resorption. Diversities in plasma membrane H+ flux pathways, which may co-operate or compete, are essential to adjust osteoclast functions in variable conditions.
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12
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Cotter K, Capecci J, Sennoune S, Huss M, Maier M, Martinez-Zaguilan R, Forgac M. Activity of plasma membrane V-ATPases is critical for the invasion of MDA-MB231 breast cancer cells. J Biol Chem 2014; 290:3680-92. [PMID: 25505184 DOI: 10.1074/jbc.m114.611210] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The vacuolar (H(+))-ATPases (V-ATPases) are a family of ATP-driven proton pumps that couple ATP hydrolysis with translocation of protons across membranes. Previous studies have implicated V-ATPases in cancer cell invasion. It has been proposed that V-ATPases participate in invasion by localizing to the plasma membrane and causing acidification of the extracellular space. To test this hypothesis, we utilized two separate approaches to specifically inhibit plasma membrane V-ATPases. First, we stably transfected highly invasive MDA-MB231 cells with a V5-tagged construct of the membrane-embedded c subunit of the V-ATPase, allowing for extracellular expression of the V5 epitope. We evaluated the effect of addition of a monoclonal antibody directed against the V5 epitope on both V-ATPase-mediated proton translocation across the plasma membrane and invasion using an in vitro Matrigel assay. The addition of anti-V5 antibody resulted in acidification of the cytosol and a decrease in V-ATPase-dependent proton flux across the plasma membrane in transfected but not control (untransfected) cells. These results demonstrate that the anti-V5 antibody inhibits activity of plasma membrane V-ATPases in transfected cells. Addition of the anti-V5 antibody also inhibited in vitro invasion of transfected (but not untransfected) cells. Second, we utilized a biotin-conjugated form of the specific V-ATPase inhibitor bafilomycin. When bound to streptavidin, this compound cannot cross the plasma membrane. Addition of this compound to MDA-MB231 cells also inhibited in vitro invasion. These studies suggest that plasma membrane V-ATPases play an important role in invasion of breast cancer cells.
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Affiliation(s)
- Kristina Cotter
- From the Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine and the Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts 02111
| | - Joseph Capecci
- From the Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine and the Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts 02111
| | - Souad Sennoune
- the Department of Cell Physiology and Molecular Biophysics, Texas Tech University, Lubbock, Texas 79430
| | - Markus Huss
- the Department of Biology/Chemistry, Division of Animal Physiology, University of Osnabrück, 49069 Osnabrück, Germany, and
| | - Martin Maier
- the Institute of Organic Chemistry, University of Tuebingen, 72076 Tuebingen, Germany
| | - Raul Martinez-Zaguilan
- the Department of Cell Physiology and Molecular Biophysics, Texas Tech University, Lubbock, Texas 79430
| | - Michael Forgac
- From the Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine and the Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts 02111,
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13
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Richardson RA, Papachristos K, Read DJ, Harlen OG, Harrison M, Paci E, Muench SP, Harris SA. Understanding the apparent stator-rotor connections in the rotary ATPase family using coarse-grained computer modeling. Proteins 2014; 82:3298-311. [PMID: 25174610 DOI: 10.1002/prot.24680] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/14/2014] [Accepted: 08/06/2014] [Indexed: 11/12/2022]
Abstract
Advances in structural biology, such as cryo-electron microscopy (cryo-EM) have allowed for a number of sophisticated protein complexes to be characterized. However, often only a static snapshot of a protein complex is visualized despite the fact that conformational change is frequently inherent to biological function, as is the case for molecular motors. Computer simulations provide valuable insights into the different conformations available to a particular system that are not accessible using conventional structural techniques. For larger proteins and protein complexes, where a fully atomistic description would be computationally prohibitive, coarse-grained simulation techniques such as Elastic Network Modeling (ENM) are often employed, whereby each atom or group of atoms is linked by a set of springs whose properties can be customized according to the system of interest. Here we compare ENM with a recently proposed continuum model known as Fluctuating Finite Element Analysis (FFEA), which represents the biomolecule as a viscoelastic solid subject to thermal fluctuations. These two complementary computational techniques are used to answer a critical question in the rotary ATPase family; implicit within these motors is the need for a rotor axle and proton pump to rotate freely of the motor domain and stator structures. However, current single particle cryo-EM reconstructions have shown an apparent connection between the stators and rotor axle or pump region, hindering rotation. Both modeling approaches show a possible role for this connection and how it would significantly constrain the mobility of the rotary ATPase family.
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Affiliation(s)
- Robin A Richardson
- School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
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14
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Ueno H, Minagawa Y, Hara M, Rahman S, Yamato I, Muneyuki E, Noji H, Murata T, Iino R. Torque generation of Enterococcus hirae V-ATPase. J Biol Chem 2014; 289:31212-23. [PMID: 25258315 DOI: 10.1074/jbc.m114.598177] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
V-ATPase (V(o)V1) converts the chemical free energy of ATP into an ion-motive force across the cell membrane via mechanical rotation. This energy conversion requires proper interactions between the rotor and stator in V(o)V1 for tight coupling among chemical reaction, torque generation, and ion transport. We developed an Escherichia coli expression system for Enterococcus hirae V(o)V1 (EhV(o)V1) and established a single-molecule rotation assay to measure the torque generated. Recombinant and native EhV(o)V1 exhibited almost identical dependence of ATP hydrolysis activity on sodium ion and ATP concentrations, indicating their functional equivalence. In a single-molecule rotation assay with a low load probe at high ATP concentration, EhV(o)V1 only showed the "clear" state without apparent backward steps, whereas EhV1 showed two states, "clear" and "unclear." Furthermore, EhV(o)V1 showed slower rotation than EhV1 without the three distinct pauses separated by 120° that were observed in EhV1. When using a large probe, EhV(o)V1 showed faster rotation than EhV1, and the torque of EhV(o)V1 estimated from the continuous rotation was nearly double that of EhV1. On the other hand, stepping torque of EhV1 in the clear state was comparable with that of EhV(o)V1. These results indicate that rotor-stator interactions of the V(o) moiety and/or sodium ion transport limit the rotation driven by the V1 moiety, and the rotor-stator interactions in EhV(o)V1 are stabilized by two peripheral stalks to generate a larger torque than that of isolated EhV1. However, the torque value was substantially lower than that of other rotary ATPases, implying the low energy conversion efficiency of EhV(o)V1.
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Affiliation(s)
- Hiroshi Ueno
- From the Department of Physics, Faculty of Science and Engineering, Chuo University, Tokyo 112-8551, Japan
| | - Yoshihiro Minagawa
- the Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Mayu Hara
- the Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Suhaila Rahman
- the Department of Biological Science and Technology, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Ichiro Yamato
- the Department of Biological Science and Technology, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Eiro Muneyuki
- From the Department of Physics, Faculty of Science and Engineering, Chuo University, Tokyo 112-8551, Japan
| | - Hiroyuki Noji
- the Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Takeshi Murata
- the Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan, JST, PRESTO, Chiba 263-8522, Japan,
| | - Ryota Iino
- the Okazaki Institute for Integrative Bioscience, Institute for Molecular Science, National Institutes of Natural Sciences, Aichi 444-8787, Japan, and the Department of Functional Molecular Science, School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Kanagawa 240-0193, Japan
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15
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Muench SP, Rawson S, Eyraud V, Delmas AF, Da Silva P, Phillips C, Trinick J, Harrison MA, Gressent F, Huss M. PA1b inhibitor binding to subunits c and e of the vacuolar ATPase reveals its insecticidal mechanism. J Biol Chem 2014; 289:16399-408. [PMID: 24795045 PMCID: PMC4047407 DOI: 10.1074/jbc.m113.541250] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 04/14/2014] [Indexed: 12/03/2022] Open
Abstract
The vacuolar ATPase (V-ATPase) is a 1MDa transmembrane proton pump that operates via a rotary mechanism fuelled by ATP. Essential for eukaryotic cell homeostasis, it plays central roles in bone remodeling and tumor invasiveness, making it a key therapeutic target. Its importance in arthropod physiology also makes it a promising pesticide target. The major challenge in designing lead compounds against the V-ATPase is its ubiquitous nature, such that any therapeutic must be capable of targeting particular isoforms. Here, we have characterized the binding site on the V-ATPase of pea albumin 1b (PA1b), a small cystine knot protein that shows exquisitely selective inhibition of insect V-ATPases. Electron microscopy shows that PA1b binding occurs across a range of equivalent sites on the c ring of the membrane domain. In the presence of Mg·ATP, PA1b localizes to a single site, distant from subunit a, which is predicted to be the interface for other inhibitors. Photoaffinity labeling studies show radiolabeling of subunits c and e. In addition, weevil resistance to PA1b is correlated with bafilomycin resistance, caused by mutation of subunit c. The data indicate a binding site to which both subunits c and e contribute and inhibition that involves locking the c ring rotor to a static subunit e and not subunit a. This has implications for understanding the V-ATPase mechanism and that of inhibitors with therapeutic or pesticidal potential. It also provides the first evidence for the position of subunit e within the complex.
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Affiliation(s)
- Stephen P Muench
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom,
| | - Shaun Rawson
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - Vanessa Eyraud
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Agnès F Delmas
- the Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique Unité Propre de Recherche 4301, Rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Pedro Da Silva
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Clair Phillips
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - John Trinick
- the School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom, and
| | - Michael A Harrison
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - Frédéric Gressent
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Markus Huss
- Abteilung Tierphysiologie, Fachbereich Biologie/Chemie Universität Osnabrück, 49069 Osnabrück, Germany
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16
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Flexibility within the rotor and stators of the vacuolar H+-ATPase. PLoS One 2013; 8:e82207. [PMID: 24312643 PMCID: PMC3846802 DOI: 10.1371/journal.pone.0082207] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 10/21/2013] [Indexed: 11/19/2022] Open
Abstract
The V-ATPase is a membrane-bound protein complex which pumps protons across the membrane to generate a large proton motive force through the coupling of an ATP-driven 3-stroke rotary motor (V1) to a multistroke proton pump (Vo). This is done with near 100% efficiency, which is achieved in part by flexibility within the central rotor axle and stator connections, allowing the system to flex to minimise the free energy loss of conformational changes during catalysis. We have used electron microscopy to reveal distinctive bending along the V-ATPase complex, leading to angular displacement of the V1 domain relative to the Vo domain to a maximum of ~30°. This has been complemented by elastic network normal mode analysis that shows both flexing and twisting with the compliance being located in the rotor axle, stator filaments, or both. This study provides direct evidence of flexibility within the V-ATPase and by implication in related rotary ATPases, a feature predicted to be important for regulation and their high energetic efficiencies.
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17
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Kishikawa JI, Nakanishi A, Furuike S, Tamakoshi M, Yokoyama K. Molecular basis of ADP inhibition of vacuolar (V)-type ATPase/synthase. J Biol Chem 2013; 289:403-12. [PMID: 24247239 DOI: 10.1074/jbc.m113.523498] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Reduction of ATP hydrolysis activity of vacuolar-type ATPase/synthase (V0V1) as a result of ADP inhibition occurs as part of the normal mechanism of V0V1 of Thermus thermophilus but not V0V1 of Enterococcus hirae or eukaryotes. To investigate the molecular basis for this difference, domain-swapped chimeric V1 consisting of both T. thermophilus and E. hirae enzymes were generated, and their function was analyzed. The data showed that the interaction between the nucleotide binding and C-terminal domains of the catalytic A subunit from E. hirae V1 is central to increasing binding affinity of the chimeric V1 for phosphate, resulting in reduction of the ADP inhibition. These findings together with a comparison of the crystal structures of T. thermophilus V1 with E. hirae V1 strongly suggest that the A subunit adopts a conformation in T. thermophilus V1 different from that in E. hirae V1. This key difference results in ADP inhibition of T. thermophilus V1 by abolishing the binding affinity for phosphate during ATP hydrolysis.
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Affiliation(s)
- Jun-ichi Kishikawa
- From the Department of Molecular Biosciences, Kyoto Sangyo University, Motoyama Kamigamo, Kita-ku, Kyoto 603-8555, Japan
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18
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Uner NE, Nishikawa Y, Okuno D, Nakano M, Yokoyama K, Noji H. Single-molecule analysis of inhibitory pausing states of V1-ATPase. J Biol Chem 2012; 287:28327-35. [PMID: 22736762 DOI: 10.1074/jbc.m112.381194] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
V(1)-ATPase, the hydrophilic V-ATPase domain, is a rotary motor fueled by ATP hydrolysis. Here, we found that Thermus thermophilus V(1)-ATPase shows two types of inhibitory pauses interrupting continuous rotation: a short pause (SP, 4.2 s) that occurred frequently during rotation, and a long inhibitory pause (LP, >30 min) that terminated all active rotations. Both pauses occurred at the same angle for ATP binding and hydrolysis. Kinetic analysis revealed that the time constants of inactivation into and activation from the SP were too short to represent biochemically predicted ADP inhibition, suggesting that SP is a newly identified inhibitory state of V(1)-ATPase. The time constant of inactivation into LP was 17 min, consistent with one of the two time constants governing the inactivation process observed in bulk ATPase assay. When forcibly rotated in the forward direction, V(1) in LP resumed active rotation. Solution ADP suppressed the probability of mechanical activation, suggesting that mechanical rotation enhanced inhibitory ADP release. These features were highly consistent with mechanical activation of ADP-inhibited F(1), suggesting that LP represents the ADP-inhibited state of V(1)-ATPase. Mechanical activation largely depended on the direction and angular displacement of forced rotation, implying that V(1)-ATPase rotation modulates the off rate of ADP.
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Affiliation(s)
- Naciye Esma Uner
- Department of Biotechnology, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
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19
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Qin A, Cheng TS, Pavlos NJ, Lin Z, Dai KR, Zheng MH. V-ATPases in osteoclasts: structure, function and potential inhibitors of bone resorption. Int J Biochem Cell Biol 2012; 44:1422-35. [PMID: 22652318 DOI: 10.1016/j.biocel.2012.05.014] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 05/18/2012] [Accepted: 05/18/2012] [Indexed: 01/06/2023]
Abstract
The vacuolar-type H(+)-ATPase (V-ATPase) proton pump is a macromolecular complex composed of at least 14 subunits organized into two functional domains, V(1) and V(0). The complex is located on the ruffled border plasma membrane of bone-resorbing osteoclasts, mediating extracellular acidification for bone demineralization during bone resorption. Genetic studies from mice to man implicate a critical role for V-ATPase subunits in osteoclast-related diseases including osteopetrosis and osteoporosis. Thus, the V-ATPase complex is a potential molecular target for the development of novel anti-resorptive agents useful for the treatment of osteolytic diseases. Here, we review the current structure and function of V-ATPase subunits, emphasizing their exquisite roles in osteoclastic function. In addition, we compare several distinct classes of V-ATPase inhibitors with specific inhibitory effects on osteoclasts. Understanding the structure-function relationship of the osteoclast V-ATPase may lead to the development of osteoclast-specific V-ATPase inhibitors that may serve as alternative therapies for the treatment of osteolytic diseases.
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Affiliation(s)
- A Qin
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Crawley, Australia.
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20
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Finnigan GC, Cronan GE, Park HJ, Srinivasan S, Quiocho FA, Stevens TH. Sorting of the yeast vacuolar-type, proton-translocating ATPase enzyme complex (V-ATPase): identification of a necessary and sufficient Golgi/endosomal retention signal in Stv1p. J Biol Chem 2012; 287:19487-500. [PMID: 22496448 DOI: 10.1074/jbc.m112.343814] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Subunit a of the yeast vacuolar-type, proton-translocating ATPase enzyme complex (V-ATPase) is responsible for both proton translocation and subcellular localization of this highly conserved molecular machine. Inclusion of the Vph1p isoform causes the V-ATPase complex to traffic to the vacuolar membrane, whereas incorporation of Stv1p causes continued cycling between the trans-Golgi and endosome. We previously demonstrated that this targeting information is contained within the cytosolic, N-terminal portion of V-ATPase subunit a (Stv1p). To identify residues responsible for sorting of the Golgi isoform of the V-ATPase, a random mutagenesis was performed on the N terminus of Stv1p. Subsequent characterization of mutant alleles led to the identification of a short peptide sequence, W(83)KY, that is necessary for proper Stv1p localization. Based on three-dimensional homology modeling to the Meiothermus ruber subunit I, we propose a structural model of the intact Stv1p-containing V-ATPase demonstrating the accessibility of the W(83)KY sequence to retrograde sorting machinery. Finally, we characterized the sorting signal within the context of a reconstructed Stv1p ancestor (Anc.Stv1). This evolutionary intermediate includes an endogenous W(83)KY sorting motif and is sufficient to compete with sorting of the native yeast Stv1p V-ATPase isoform. These data define a novel sorting signal that is both necessary and sufficient for trafficking of the V-ATPase within the Golgi/endosomal network.
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Affiliation(s)
- Gregory C Finnigan
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA
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21
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Baumann O, Walz B. The blowfly salivary gland - a model system for analyzing the regulation of plasma membrane V-ATPase. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:450-458. [PMID: 22133312 DOI: 10.1016/j.jinsphys.2011.11.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 11/17/2011] [Accepted: 11/18/2011] [Indexed: 05/31/2023]
Abstract
Vacuolar H(+)-ATPases (V-ATPases) are heteromultimeric proteins that use the energy of ATP hydrolysis for the electrogenic transport of protons across membranes. They are common to all eukaryotic cells and are located in the plasma membrane or in membranes of acid organelles. In many insect epithelia, V-ATPase molecules reside in large numbers in the apical plasma membrane and create an electrochemical proton gradient that is used for the acidification or alkalinization of the extracellular space, the secretion or reabsorption of ions and fluids, the import of nutrients, and diverse other cellular activities. Here, we summarize our results on the functions and regulation of V-ATPase in the tubular salivary gland of the blowfly Calliphora vicina. In this gland, V-ATPase activity energizes the secretion of a KCl-rich saliva in response to the neurohormone serotonin (5-HT). Because of particular morphological and physiological features, the blowfly salivary glands are a superior and exemplary system for the analysis of the intracellular signaling pathways and mechanisms that modulate V-ATPase activity and solute transport in an insect epithelium.
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Affiliation(s)
- Otto Baumann
- Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany.
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22
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Abstract
Lysosomes, the terminal organelles on the endocytic pathway, digest macromolecules and make their components available to the cell as nutrients. Hydrolytic enzymes specific to a wide range of targets reside within the lysosome; these enzymes are activated by the highly acidic pH (between 4.5 and 5.0) in the organelles' interior. Lysosomes generate and maintain their pH gradients by using the activity of a proton-pumping V-type ATPase, which uses metabolic energy in the form of ATP to pump protons into the lysosome lumen. Because this activity separates electric charge and generates a transmembrane voltage, another ion must move to dissipate this voltage for net pumping to occur. This so-called counterion may be either a cation (moving out of the lysosome) or an anion (moving into the lysosome). Recent data support the involvement of ClC-7, a Cl(-)/H(+) antiporter, in this process, although many open questions remain as to this transporter's involvement. Although functional results also point to a cation transporter, its molecular identity remains uncertain. Both the V-ATPase and the counterion transporter are likely to be important players in the mechanisms determining the steady-state pH of the lysosome interior. Exciting new results suggest that lysosomal pH may be dynamically regulated in some cell types.
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Affiliation(s)
- Joseph A Mindell
- Membrane Transport Biophysics Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
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23
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Promiscuous archaeal ATP synthase concurrently coupled to Na+ and H+ translocation. Proc Natl Acad Sci U S A 2012; 109:947-52. [PMID: 22219361 DOI: 10.1073/pnas.1115796109] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
ATP synthases are the primary source of ATP in all living cells. To catalyze ATP synthesis, these membrane-associated complexes use a rotary mechanism powered by the transmembrane diffusion of ions down a concentration gradient. ATP synthases are assumed to be driven either by H(+) or Na(+), reflecting distinct structural motifs in their membrane domains, and distinct metabolisms of the host organisms. Here, we study the methanogenic archaeon Methanosarcina acetivorans using assays of ATP hydrolysis and ion transport in inverted membrane vesicles, and experimentally demonstrate that the rotary mechanism of its ATP synthase is coupled to the concurrent translocation of both H(+) and Na(+) across the membrane under physiological conditions. Using free-energy molecular simulations, we explain this unprecedented observation in terms of the ion selectivity of the binding sites in the membrane rotor, which appears to have been tuned via amino acid substitutions so that ATP synthesis in M. acetivorans can be driven by the H(+) and Na(+) gradients resulting from methanogenesis. We propose that this promiscuity is a molecular mechanism of adaptation to life at the thermodynamic limit.
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Furuike S, Nakano M, Adachi K, Noji H, Kinosita K, Yokoyama K. Resolving stepping rotation in Thermus thermophilus H(+)-ATPase/synthase with an essentially drag-free probe. Nat Commun 2011; 2:233. [PMID: 21407199 PMCID: PMC3072102 DOI: 10.1038/ncomms1215] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 01/26/2011] [Indexed: 11/09/2022] Open
Abstract
Vacuole-type ATPases (VoV1) and FoF1 ATP synthases couple ATP hydrolysis/synthesis in the soluble V1 or F1 portion with proton (or Na+) flow in the membrane-embedded Vo or Fo portion through rotation of one common shaft. Here we show at submillisecond resolutions the ATP-driven rotation of isolated V1 and the whole VoV1 from Thermus thermophilus, by attaching a 40-nm gold bead for which viscous drag is almost negligible. V1 made 120° steps, commensurate with the presence of three catalytic sites. Dwells between the steps involved at least two events other than ATP binding, one likely to be ATP hydrolysis. VoV1 exhibited 12 dwell positions per revolution, consistent with the 12-fold symmetry of the Vo rotor in T. thermophilus. Unlike F1 that undergoes 80°–40° substepping, chemo-mechanical checkpoints in isolated V1 are all at the ATP-waiting position, and Vo adds further bumps through stator–rotor interactions outside and remote from V1. Rotary ATPases FoF1 and VoV1 couple ATP hydrolysis with proton flow. Furuike et al. observe ATP-driven rotation in V1 and VoV1, at submillisecond resolution, and find that rate-limiting reactions in V1 all occur at the same angle, and stator–rotor interactions in Vo introduce additional checkpoints.
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Affiliation(s)
- Shou Furuike
- Department of Physics, Faculty of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 169-8555, Japan
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25
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26
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Abstract
AbstractThe rotary ATPase family of membrane protein complexes may have only three members, but each one plays a fundamental role in biological energy conversion. The F1Fo-ATPase (F-ATPase) couples ATP synthesis to the electrochemical membrane potential in bacteria, mitochondria and chloroplasts, while the vacuolar H+-ATPase (V-ATPase) operates as an ATP-driven proton pump in eukaryotic membranes. In different species of archaea and bacteria, the A1Ao-ATPase (A-ATPase) can function as either an ATP synthase or an ion pump. All three of these multi-subunit complexes are rotary molecular motors, sharing a fundamentally similar mechanism in which rotational movement drives the energy conversion process. By analogy to macroscopic systems, individual subunits can be assigned to rotor, axle or stator functions. Recently, three-dimensional reconstructions from electron microscopy and single particle image processing have led to a significant step forward in understanding of the overall architecture of all three forms of these complexes and have allowed the organisation of subunits within the rotor and stator parts of the motors to be more clearly mapped out. This review describes the emerging consensus regarding the organisation of the rotor and stator components of V-, A- and F-ATPases, examining core similarities that point to a common evolutionary origin, and highlighting key differences. In particular, it discusses how newly revealed variation in the complexity of the inter-domain connections may impact on the mechanics and regulation of these molecular machines.
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27
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Ma B, Xiang Y, An L. Structural bases of physiological functions and roles of the vacuolar H(+)-ATPase. Cell Signal 2011; 23:1244-56. [PMID: 21397012 DOI: 10.1016/j.cellsig.2011.03.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 03/03/2011] [Indexed: 12/09/2022]
Abstract
Vacuolar-type H(+)-ATPases (V-ATPases) is a large multi-protein complex containing at least 14 different subunits, in which subunits A, B, C, D, E, F, G, and H compose the peripheral 500-kDa V(1) responsible for ATP hydrolysis, and subunits a, c, c', c″, and d assembly the 250-kDa membrane-integral V(0) harboring the rotary mechanism to transport protons across the membrane. The assembly of V-ATPases requires the presence of all V(1) and V(0) subunits, in which the V(1) must be completely assembled prior to association with the V(0), accordingly the V(0) failing to assemble cannot provide a membrane anchor for the V(1), thereby prohibiting membrane association of the V-ATPase subunits. The V-ATPase mediates acidification of intracellular compartments and regulates diverse critical physiological processes of cell for functions of its numerous functional subunits. The core catalytic mechanism of the V-ATPase is a rotational catalytic mechanism. The V-ATPase holoenzyme activity is regulated by the reversible assembly/disassembly of the V(1) and V(0), the targeting and recycling of V-ATPase-containing vesicles to and from the plasma membrane, the coupling ratio between ATP hydrolysis and proton pumping, ATP, Ca(2+), and its inhibitors and activators.
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Affiliation(s)
- Binyun Ma
- Key Laboratory of Arid and Grassland Agroecology of Ministry of Education, School of Life Sciences, Lanzhou University, 730000, Lanzhou, China
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28
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A genome-wide enhancer screen implicates sphingolipid composition in vacuolar ATPase function in Saccharomyces cerevisiae. Genetics 2010; 187:771-83. [PMID: 21196517 DOI: 10.1534/genetics.110.125567] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The function of the vacuolar H(+)-ATPase (V-ATPase) enzyme complex is to acidify organelles; this process is critical for a variety of cellular processes and has implications in human disease. There are five accessory proteins that assist in assembly of the membrane portion of the complex, the V(0) domain. To identify additional elements that affect V-ATPase assembly, trafficking, or enzyme activity, we performed a genome-wide enhancer screen in the budding yeast Saccharomyces cerevisiae with two mutant assembly factor alleles, VMA21 with a dysfunctional ER retrieval motif (vma21QQ) and vma21QQ in combination with voa1Δ, a nonessential assembly factor. These alleles serve as sensitized genetic backgrounds that have reduced V-ATPase enzyme activity. Genes were identified from a variety of cellular pathways including a large number of trafficking-related components; we characterized two redundant gene pairs, HPH1/HPH2 and ORM1/ORM2. Both sets demonstrated synthetic growth defects in combination with the vma21QQ allele. A loss of either the HPH or ORM gene pairs alone did not result in a decrease in vacuolar acidification or defects in V-ATPase assembly. While the Hph proteins are not required for V-ATPase function, Orm1p and Orm2p are required for full V-ATPase enzyme function. Consistent with the documented role of the Orm proteins in sphingolipid regulation, we have found that inhibition of sphingolipid synthesis alleviates Orm-related growth defects.
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29
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Kartner N, Yao Y, Li K, Crasto GJ, Datti A, Manolson MF. Inhibition of osteoclast bone resorption by disrupting vacuolar H+-ATPase a3-B2 subunit interaction. J Biol Chem 2010; 285:37476-90. [PMID: 20837476 DOI: 10.1074/jbc.m110.123281] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vacuolar H(+)-ATPases (V-ATPases) are highly expressed in ruffled borders of bone-resorbing osteoclasts, where they play a crucial role in skeletal remodeling. To discover protein-protein interactions with the a subunit in mammalian V-ATPases, a GAL4 activation domain fusion library was constructed from an in vitro osteoclast model, receptor activator of NF-κB ligand-differentiated RAW 264.7 cells. This library was screened with a bait construct consisting of a GAL4 binding domain fused to the N-terminal domain of V-ATPase a3 subunit (NTa3), the a subunit isoform that is highly expressed in osteoclasts (a1 and a2 are also expressed, to a lesser degree, whereas a4 is kidney-specific). One of the prey proteins identified was the V-ATPase B2 subunit, which is also highly expressed in osteoclasts (B1 is not expressed). Further characterization, using pulldown and solid-phase binding assays, revealed an interaction between NTa3 and the C-terminal domains of both B1 and B2 subunits. Dual B binding domains of equal affinity were observed in NTa, suggesting a possible model for interaction between these subunits in the V-ATPase complex. Furthermore, the a3-B2 interaction appeared to be moderately favored over a1, a2, and a4 interactions with B2, suggesting a mechanism for the specific subunit assembly of plasma membrane V-ATPase in osteoclasts. Solid-phase binding assays were subsequently used to screen a chemical library for inhibitors of the a3-B2 interaction. A small molecule benzohydrazide derivative was found to inhibit osteoclast resorption with an IC(50) of ∼1.2 μm on both synthetic hydroxyapatite surfaces and dentin slices, without significantly affecting RAW 264.7 cell viability or receptor activator of NF-κB ligand-mediated osteoclast differentiation. Further understanding of these interactions and inhibitors may contribute to the design of novel therapeutics for bone loss disorders, such as osteoporosis and rheumatoid arthritis.
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Affiliation(s)
- Norbert Kartner
- Dental Research Institute, Faculty of Dentistry, University of Toronto, Toronto, Ontario M5G 1G6 Canada
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30
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Jones RPO, Durose LJ, Phillips C, Keen JN, Findlay JBC, Harrison MA. A site-directed cross-linking approach to the characterization of subunit E-subunit G contacts in the vacuolar H+-ATPase stator. Mol Membr Biol 2010; 27:147-59. [DOI: 10.3109/09687681003796441] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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31
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Nakanishi-Matsui M, Sekiya M, Nakamoto RK, Futai M. The mechanism of rotating proton pumping ATPases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1343-52. [PMID: 20170625 DOI: 10.1016/j.bbabio.2010.02.014] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 02/08/2010] [Accepted: 02/11/2010] [Indexed: 11/27/2022]
Abstract
Two proton pumps, the F-ATPase (ATP synthase, FoF1) and the V-ATPase (endomembrane proton pump), have different physiological functions, but are similar in subunit structure and mechanism. They are composed of a membrane extrinsic (F1 or V1) and a membrane intrinsic (Fo or Vo) sector, and couple catalysis of ATP synthesis or hydrolysis to proton transport by a rotational mechanism. The mechanism of rotation has been extensively studied by kinetic, thermodynamic and physiological approaches. Techniques for observing subunit rotation have been developed. Observations of micron-length actin filaments, or polystyrene or gold beads attached to rotor subunits have been highly informative of the rotational behavior of ATP hydrolysis-driven rotation. Single molecule FRET experiments between fluorescent probes attached to rotor and stator subunits have been used effectively in monitoring proton motive force-driven rotation in the ATP synthesis reaction. By using small gold beads with diameters of 40-60 nm, the E. coli F1 sector was found to rotate at surprisingly high speeds (>400 rps). This experimental system was used to assess the kinetics and thermodynamics of mutant enzymes. The results revealed that the enzymatic reaction steps and the timing of the domain interactions among the beta subunits, or between the beta and gamma subunits, are coordinated in a manner that lowers the activation energy for all steps and avoids deep energy wells through the rotationally-coupled steady-state reaction. In this review, we focus on the mechanism of steady-state F1-ATPase rotation, which maximizes the coupling efficiency between catalysis and rotation.
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Affiliation(s)
- Mayumi Nakanishi-Matsui
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694, Japan.
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Ediger B, Melman SD, Pappas DL, Finch M, Applen J, Parra KJ. The tether connecting cytosolic (N terminus) and membrane (C terminus) domains of yeast V-ATPase subunit a (Vph1) is required for assembly of V0 subunit d. J Biol Chem 2009; 284:19522-32. [PMID: 19473972 DOI: 10.1074/jbc.m109.013375] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
V-ATPases are molecular motors that reversibly disassemble in vivo. Anchored in the membrane is subunit a. Subunit a has a movable N terminus that switches positions during disassembly and reassembly. Deletions were made at residues securing the N terminus of subunit a (yeast isoform Vph1) to its membrane-bound C-terminal domain in order to understand the role of this conserved region for V-ATPase function. Shrinking of the tether made cells pH-sensitive (vma phenotype) because assembly of V(0) subunit d was harmed. Subunit d did not co-immunoprecipitate with subunit a and the c-ring. Cells contained pools of V(1) and V(0)(-d) that failed to form V(1)V(0), and very low levels of V-ATPase subunits were found at the membrane. Although subunit d expression was stable and at wild-type levels, growth defects were rescued by exogenous VMA6 (subunit d). Stable V(1)V(0) assembled after yeast cells were co-transformed with VMA6 and mutant VPH1. Tether-less V(1)V(0) was delivered to the vacuole and active. It retained 63-71% of the wild-type activity and was responsive to glucose. Tether-less V(1)V(0) disassembled and reassembled after brief glucose depletion and readdition. The N terminus retained binding to V(1) subunits and the C terminus to phosphofructokinase. Thus, no major structural change was generated at the N and C termini of subunit a. We concluded that early steps of V(0) assembly and trafficking were likely impaired by shorter tethers and rescued by VMA6.
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Affiliation(s)
- Benjamin Ediger
- Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131, USA
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Takeda M, Suno-Ikeda C, Shimabukuro K, Yoshida M, Yokoyama K. Mechanism of inhibition of the V-type molecular motor by tributyltin chloride. Biophys J 2009; 96:1210-7. [PMID: 19186155 DOI: 10.1016/j.bpj.2008.10.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Accepted: 10/09/2008] [Indexed: 11/30/2022] Open
Abstract
Tributyltin chloride (TBT-Cl) is an endocrine disruptor found in many animal species, and it is also known to be an inhibitor for the V-ATPases that are emerging as potential targets in the treatment of diseases such as osteoporosis and cancer. We demonstrated by using biochemical and single-molecular imaging techniques that TBT-Cl arrests an elementary step for rotary catalysis of the V(1) motor domain. In the presence of TBT-Cl, the consecutive rotation of V(1) paused for a long duration ( approximately 0.5 s), even at saturated ATP concentrations, and the pausing positions were localized at 120 degrees intervals. Analysis of both the pausing time and moving time revealed that TBT-Cl has little effect on the binding affinity for ATP, but, rather, it arrests the catalytic event(s). This is the first report to demonstrate that an inhibitor arrests an elementary step for rotary catalysis of a V-type ATP-driven rotary motor.
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Affiliation(s)
- Mizuho Takeda
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, Japan
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Zhang Z, Zheng Y, Mazon H, Milgrom E, Kitagawa N, Kish-Trier E, Heck AJR, Kane PM, Wilkens S. Structure of the yeast vacuolar ATPase. J Biol Chem 2008; 283:35983-95. [PMID: 18955482 PMCID: PMC2602884 DOI: 10.1074/jbc.m805345200] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 10/15/2008] [Indexed: 01/01/2023] Open
Abstract
The subunit architecture of the yeast vacuolar ATPase (V-ATPase) was analyzed by single particle transmission electron microscopy and electrospray ionization (ESI) tandem mass spectrometry. A three-dimensional model of the intact V-ATPase was calculated from two-dimensional projections of the complex at a resolution of 25 angstroms. Images of yeast V-ATPase decorated with monoclonal antibodies against subunits A, E, and G position subunit A within the pseudo-hexagonal arrangement in the V1, the N terminus of subunit G in the V1-V0 interface, and the C terminus of subunit E at the top of the V1 domain. ESI tandem mass spectrometry of yeast V1-ATPase showed that subunits E and G are most easily lost in collision-induced dissociation, consistent with a peripheral location of the subunits. An atomic model of the yeast V-ATPase was generated by fitting of the available x-ray crystal structures into the electron microscopy-derived electron density map. The resulting atomic model of the yeast vacuolar ATPase serves as a framework to help understand the role the peripheral stalk subunits are playing in the regulation of the ATP hydrolysis driven proton pumping activity of the vacuolar ATPase.
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Affiliation(s)
- Zhenyu Zhang
- Department of Biochemistry, University of California, Riverside, California 92521, USA
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35
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Diepholz M, Venzke D, Prinz S, Batisse C, Flörchinger B, Rössle M, Svergun DI, Böttcher B, Féthière J. A Different Conformation for EGC Stator Subcomplex in Solution and in the Assembled Yeast V-ATPase: Possible Implications for Regulatory Disassembly. Structure 2008; 16:1789-98. [DOI: 10.1016/j.str.2008.09.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 09/17/2008] [Accepted: 09/18/2008] [Indexed: 11/29/2022]
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36
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Structural organization of the V-ATPase and its implications for regulatory assembly and disassembly. Biochem Soc Trans 2008; 36:1027-31. [DOI: 10.1042/bst0361027] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
V-ATPases (vacuolar ATPases) are membrane-bound multiprotein complexes that are localized in the endomembrane systems of eukaryotic cells and in the plasma membranes of some specialized cells. They couple ATP hydrolysis with the transport of protons across membranes. On nutrient shortage, V-ATPases disassemble into a membrane-embedded part (V0), which contains the proton translocation machinery, and an extrinsic part (V1), which carries the nucleotide-binding sites. Disassembly decouples ATP hydrolysis and proton translocation. Furthermore, the disassembled parts are inactive, leading to an efficient shutdown of ATP consumption. On restoring the nutrient levels, V1 and V0 reassemble and restore ATP-hydrolysis activity coupled with proton translocation. This reversible assembly/disassembly process has certain conformational constraints, which are best fulfilled by adopting a unique conformation before disassembly.
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37
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Ryan M, Graham LA, Stevens TH. Voa1p functions in V-ATPase assembly in the yeast endoplasmic reticulum. Mol Biol Cell 2008; 19:5131-42. [PMID: 18799613 DOI: 10.1091/mbc.e08-06-0629] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The yeast Saccharomyces cerevisiae vacuolar ATPase (V-ATPase) is a multisubunit complex divided into two sectors: the V(1) sector catalyzes ATP hydrolysis and the V(0) sector translocates protons, resulting in acidification of its resident organelle. Four protein factors participate in V(0) assembly. We have discovered a fifth V(0) assembly factor, Voa1p (YGR106C); an endoplasmic reticulum (ER)-localized integral membrane glycoprotein. The role of Voa1p in V(0) assembly was revealed in cells expressing an ER retrieval-deficient form of the V-ATPase assembly factor Vma21p (Vma21pQQ). Loss of Voa1p in vma21QQ yeast cells resulted in loss of V-ATPase function; cells were unable to acidify their vacuoles and exhibited growth defects typical of cells lacking V-ATPase. V(0) assembly was severely compromised in voa1 vma21QQ double mutants. Isolation of V(0)-Vma21p complexes indicated that Voa1p associates most strongly with Vma21p and the core proteolipid ring of V(0) subunits c, c', and c''. On assembly of the remaining three V(0) subunits (a, d, and e) into the V(0) complex, Voa1p dissociates from the now fully assembled V(0)-Vma21p complex. Our results suggest Voa1p functions with Vma21p early in V(0) assembly in the ER, but then it dissociates before exit of the V(0)-Vma21p complex from the ER for transport to the Golgi compartment.
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Affiliation(s)
- Margret Ryan
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
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38
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Nakano M, Imamura H, Toei M, Tamakoshi M, Yoshida M, Yokoyama K. ATP hydrolysis and synthesis of a rotary motor V-ATPase from Thermus thermophilus. J Biol Chem 2008; 283:20789-96. [PMID: 18492667 DOI: 10.1074/jbc.m801276200] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vacuolar-type H(+)-ATPase (V-ATPase) catalyzes ATP synthesis and hydrolysis coupled with proton translocation across membranes via a rotary motor mechanism. Here we report biochemical and biophysical catalytic properties of V-ATPase from Thermus thermophilus. ATP hydrolysis of V-ATPase was severely inhibited by entrapment of Mg-ADP in the catalytic site. In contrast, the enzyme was very active for ATP synthesis (approximately 70 s(-1)) with the K(m) values for ADP and phosphate being 4.7 +/- 0.5 and 460 +/- 30 microm, respectively. Single molecule observation showed V-ATPase rotated in a 120 degrees stepwise manner, and analysis of dwelling time allowed the binding rate constant k(on) for ATP to be estimated ( approximately 1.1 x 10(6) m(-1) s(-1)), which was much lower than the k(on) (= V(max)/K(m)) for ADP ( approximately 1.4 x 10(7) m(-1) s(-1)). The slower k(on)(ATP) than k(on)(ADP) and strong Mg-ADP inhibition may contribute to prevent wasteful consumption of ATP under in vivo conditions when the proton motive force collapses.
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Affiliation(s)
- Masahiro Nakano
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Japan
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39
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The V-ATPase in Paramecium: functional specialization by multiple gene isoforms. Pflugers Arch 2008; 457:599-607. [DOI: 10.1007/s00424-007-0417-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2007] [Revised: 11/23/2007] [Accepted: 11/29/2007] [Indexed: 11/25/2022]
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40
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Pisa KY, Huber H, Thomm M, Müller V. A sodium ion-dependent A1AO ATP synthase from the hyperthermophilic archaeon Pyrococcus furiosus. FEBS J 2007; 274:3928-38. [PMID: 17614964 DOI: 10.1111/j.1742-4658.2007.05925.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rotor subunit c of the A(1)A(O) ATP synthase of the hyperthermophilic archaeon Pyrococcus furiosus contains a conserved Na(+)-binding motif, indicating that Na(+) is a coupling ion. To experimentally address the nature of the coupling ion, we isolated the enzyme by detergent solubilization from native membranes followed by chromatographic separation techniques. The entire membrane-embedded motor domain was present in the preparation. The rotor subunit c was found to form an SDS-resistant oligomer. Under the conditions tested, the enzyme had maximal activity at 100 degrees C, had a rather broad pH optimum between pH 5.5 and 8.0, and was inhibited by diethystilbestrol and derivatives thereof. ATP hydrolysis was strictly dependent on Na(+), with a K(m) of 0.6 mM. Li(+), but not K(+), could substitute for Na(+). The Na(+) dependence was less pronounced at higher proton concentrations, indicating competition between Na(+) and H(+) for a common binding site. Moreover, inhibition of the ATPase by N',N'-dicyclohexylcarbodiimide could be relieved by Na(+). Taken together, these data demonstrate the use of Na(+) as coupling ion for the A(1)A(O) ATP synthase of Pyrococcus furiosus, the first Na(+) A(1)A(O) ATP synthase described.
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Affiliation(s)
- Kim Y Pisa
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe Universität Frankfurt, Frankfurt, Germany
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41
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Lokanath NK, Matsuura Y, Kuroishi C, Takahashi N, Kunishima N. Dimeric Core Structure of Modular Stator Subunit E of Archaeal H+-ATPase. J Mol Biol 2007; 366:933-44. [PMID: 17189637 DOI: 10.1016/j.jmb.2006.11.088] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 11/29/2006] [Accepted: 11/30/2006] [Indexed: 10/23/2022]
Abstract
Archaeal H(+)-ATPase (A-ATPase) is composed of an A(1) region that hydrolyzes ATP and an integral membrane part A(0) that conducts protons. Subunit E is a component of peripheral stator(s) that physically links A(1) and A(0) parts of the A-ATPase. Here we report the first crystal structure of subunit E of A-ATPase from Pyrococcus horikoshii OT3 at 1.85 A resolution. The protomer structure of subunit E represents a novel fold. The quaternary structure of subunit E is a homodimer, which may constitute the core part of the stator. To investigate the relationship with other stator subunit H, the complex of subunits EH was prepared and characterized using electrophoresis, mass spectrometry, N-terminal sequencing and circular dichroism spectroscopy, which revealed the polymeric and highly helical nature of the EH complex with equimolar stoichiometry of both the subunits. On the basis of the modular architecture of stator subunits, it is suggested that both cytoplasm and membrane sides of the EH complex may interact with other subunits to link A(1) and A(0) parts.
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Affiliation(s)
- Neratur K Lokanath
- Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo-Gun, Hyogo, Japan
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42
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Imamura H, Funamoto S, Yoshida M, Yokoyama K. Reconstitution in vitro of V1 complex of Thermus thermophilus V-ATPase revealed that ATP binding to the A subunit is crucial for V1 formation. J Biol Chem 2006; 281:38582-91. [PMID: 17050529 DOI: 10.1074/jbc.m608253200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vacuolar-type H(+)-ATPase (V-ATPase or V-type ATPase) is a multisubunit complex comprised of a water-soluble V(1) complex, responsible for ATP hydrolysis, and a membrane-embedded V(o) complex, responsible for proton translocation. The V(1) complex of Thermus thermophilus V-ATPase has the subunit composition of A(3)B(3)DF, in which the A and B subunits form a hexameric ring structure. A central stalk composed of the D and F subunits penetrates the ring. In this study, we investigated the pathway for assembly of the V(1) complex by reconstituting the V(1) complex from the monomeric A and B subunits and DF subcomplex in vitro. Assembly of these components into the V(1) complex required binding of ATP to the A subunit, although hydrolysis of ATP is not necessary. In the absence of the DF subcomplex, the A and B monomers assembled into A(1)B(1) and A(3)B(3) subcomplexes in an ATP binding-dependent manner, suggesting that ATP binding-dependent interaction between the A and B subunits is a crucial step of assembly into V(1) complex. Kinetic analysis of assembly of the A and B monomers into the A(1)B(1) heterodimer using fluorescence resonance energy transfer indicated that the A subunit binds ATP prior to binding the B subunit. Kinetics of binding of a fluorescent ADP analog, N-methylanthraniloyl ADP (mant-ADP), to the monomeric A subunit also supported the rapid nucleotide binding to the A subunit.
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Affiliation(s)
- Hiromi Imamura
- ATP System Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), 5800-3 Nagatsuta, Midori-ku, Yokohama 226-0026, Japan
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Owegi MA, Pappas DL, Finch MW, Bilbo SA, Resendiz CA, Jacquemin LJ, Warrier A, Trombley JD, McCulloch KM, Margalef KLM, Mertz MJ, Storms JM, Damin CA, Parra KJ. Identification of a Domain in the Vo Subunit d That Is Critical for Coupling of the Yeast Vacuolar Proton-translocating ATPase. J Biol Chem 2006; 281:30001-14. [PMID: 16891312 DOI: 10.1074/jbc.m605006200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vacuolar proton-translocating ATPase pumps consist of two domains, V(1) and V(o). Subunit d is a component of V(o) located in a central stalk that rotates during catalysis. By generating mutations, we showed that subunit d couples ATP hydrolysis and proton transport. The mutation F94A strongly uncoupled the enzyme, preventing proton transport but not ATPase activity. C-terminal mutations changed coupling as well; ATPase activity was decreased by 59-72%, whereas proton transport was not measurable (E328A) or was moderately reduced (E317A and C329A). Except for W325A, which had low levels of V(1)V(o), mutations allowed wild-type assembly regardless of the fact that subunits E and d were reduced at the membrane. N- and C-terminal deletions of various lengths were inhibitory and gradually destabilized subunit d, limiting V(1)V(o) formation. Both N and C terminus were required for V(o) assembly. The N-terminal truncation 2-19Delta prevented V(1)V(o) formation, although subunit d was available. The C terminus was required for retention of subunits E and d at the membrane. In addition, the C terminus of its bacterial homolog (subunit C from T. thermophilus) stabilized the yeast subunit d mutant 310-345Delta and allowed assembly of the rotor structure with subunits A and B. Structural features conserved between bacterial and eukaryotic subunit d and the significance of domain 3 for vacuolar proton-translocating ATPase function are discussed.
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Affiliation(s)
- Margaret A Owegi
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, USA
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Clare DK, Orlova EV, Finbow MA, Harrison MA, Findlay JBC, Saibil HR. An expanded and flexible form of the vacuolar ATPase membrane sector. Structure 2006; 14:1149-56. [PMID: 16843896 DOI: 10.1016/j.str.2006.05.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2005] [Revised: 04/28/2006] [Accepted: 05/02/2006] [Indexed: 11/20/2022]
Abstract
The vacuolar ATPase integral membrane c-ring from Nephrops norvegicus occurs in paired complexes in a double membrane. Using cryo-electron microscopy and single particle image processing of 2D crystals, we have obtained a projection structure of the c-ring of N. norvegicus. The c-ring was found to be very flexible, most likely as a result of an expanded conformation of the c subunits. This structure may support a role for the vacuolar ATPase c-rings in membrane fusion.
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Affiliation(s)
- Daniel K Clare
- School of Crystallography, Birkbeck College, University of London, Malet Street, London WC1E 7HX, United Kingdom
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45
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Nakanishi-Matsui M, Futai M. Stochastic proton pumping ATPases: from single molecules to diverse physiological roles. IUBMB Life 2006; 58:318-22. [PMID: 16754325 DOI: 10.1080/15216540600702255] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We discuss the most recent reports on two proton pumps, F-ATPase (ATP synthase) and V-ATPase (endomembrane proton pump). They are formed from similar extrinsic (F1 or V1) and intrinsic (Fo or Vo) membrane sectors, and couple chemistry and proton transport through subunit rotation for apparently different physiological roles. Emphasis is placed on the stochastic rotational catalysis of F-ATPase and isoforms of V-ATPase.
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Affiliation(s)
- Mayumi Nakanishi-Matsui
- Futai Special Laboratory, Microbial Chemistry Research Center, Microbial Chemistry Research Foundation, CREST, Japan Science, and Technology Agency, Kamiosaki, Shinagawa-ku, Tokyo, Japan
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46
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Abstract
The prokaryotic V-type ATPase/synthases (prokaryotic V-ATPases) have simpler subunit compositions than eukaryotic V-ATPases, and thus are useful subjects for studying chemical, physical and structural properties of V-ATPase. In this review, we focus on the results of recent studies on the structure/function relationships in the V-ATPase from the eubacterium Thermus thermophilus. First, we describe single-molecule analyses of T. thermophilus V-ATPase. Using the single-molecule technique, it was established that the V-ATPase is a rotary motor. Second, we discuss arrangement of subunits in V-ATPase. Third, the crystal structure of the C-subunit (homolog of eukaryotic d-subunit) is described. This funnel-shape subunit appears to cap the proteolipid ring in the V(0) domain in order to accommodate the V(1) central stalk. This structure seems essential for the regulatory reversible association/dissociation of the V(1) and the V(0) domains. Last, we discuss classification of the V-ATPase family. We propose that the term prokaryotic V-ATPases should be used rather than the term archaeal-type ATPase (A-ATPase).
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Affiliation(s)
- Ken Yokoyama
- ATP System Project, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Nagatsuta, Midori-ku, Yokohama, Japan.
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47
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Pedersen PL. Transport ATPases: structure, motors, mechanism and medicine: a brief overview. J Bioenerg Biomembr 2006; 37:349-57. [PMID: 16691464 DOI: 10.1007/s10863-005-9470-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Today we know there are four different types of ATPases that operate within biological membranes with the purpose of moving many different types of ions or molecules across these membranes. Some of these ions or molecules are transported into cells, some out of cells, and some in or out of organelles within cells. These ATPases span the biological world from bacteria to eukaryotic cells and have become most simply and commonly known as "transport ATPases." The price that each cell type pays for transport work is counted in molecules of hydrolyzed ATP, a metabolic currency that is itself regenerated by a transport ATPase working in reverse, i.e., the ATP synthase. Four major classes of transport ATPases, the P, V, F, and ABC types are now known. In addition to being involved in many different types of biological/physiological processes, mutations in these proteins also account for a large number of diseases. The purpose of this introductory article to a mini-review series on transport ATPases is to provide the reader with a very brief and focused look at this important area of research that has an interesting history and bears significance to cell physiology, biochemistry, immunology, nanotechnology, and medicine, including drug discovery. The latter involves potential applications to a whole host of diseases ranging from cancer to those that affect bones (osteoporosis), ears (hearing), eyes (macromolecular degeneration), the heart (hypercholesterolemia/cardiac arrest,), immune system (immune deficiency disease), kidney (nephrotoxicity), lungs (cystic fibrosis), pancreas (diabetes and cystic fibrosis), skin (Darier disease), and stomach (ulcers).
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Affiliation(s)
- Peter L Pedersen
- Department of Biological Chemistry, Johns Hopkins University, School of Medicine, 725 North Wolfe Street, Baltimore, Maryland, 21205-2185, USA.
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Ohira M, Smardon AM, Charsky CMH, Liu J, Tarsio M, Kane PM. The E and G Subunits of the Yeast V-ATPase Interact Tightly and Are Both Present at More Than One Copy per V1 Complex. J Biol Chem 2006; 281:22752-60. [PMID: 16774922 DOI: 10.1074/jbc.m601441200] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The E and G subunits of the yeast V-ATPase are believed to be part of the peripheral or stator stalk(s) responsible for physically and functionally linking the peripheral V1 sector, responsible for ATP hydrolysis, to the membrane V0 sector, containing the proton pore. The E and G subunits interact tightly and specifically, both on a far Western blot of yeast vacuolar proteins and in the yeast two-hybrid assay. Amino acids 13-79 of the E subunit are critical for the E-G two-hybrid interaction. Different tagged versions of the G subunit were expressed in a diploid cell, and affinity purification of cytosolic V1 sectors via a FLAG-tagged G subunit resulted in copurification of a Myc-tagged G subunit, implying more than one G subunit was present in each V1 complex. Similarly, hemagglutinin-tagged E subunit was able to affinity-purify V1 sectors containing an untagged version of the E subunit from heterozygous diploid cells, suggesting that more than one E subunit is present. Overexpression of the subunit G results in a destabilization of subunit E similar to that seen in the complete absence of subunit G (Tomashek, J. J., Graham, L. A., Hutchins, M. U., Stevens, T. H., and Klionsky, D. J. (1997) J. Biol. Chem. 272, 26787-26793). These results are consistent with recent models showing at least two peripheral stalks connecting the V1 and V0 sectors of the V-ATPase and would allow both stalks to be based on an EG dimer.
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Affiliation(s)
- Masashi Ohira
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210, USA
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Imamura H, Takeda M, Funamoto S, Shimabukuro K, Yoshida M, Yokoyama K. Rotation scheme of V1-motor is different from that of F1-motor. Proc Natl Acad Sci U S A 2005; 102:17929-33. [PMID: 16330761 PMCID: PMC1306795 DOI: 10.1073/pnas.0507764102] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Indexed: 11/18/2022] Open
Abstract
V(1), a water-soluble portion of vacuole-type ATPase (V-ATPase), is an ATP-driven rotary motor, similar to F(1)-ATPase. Hydrolysis of ATP is coupled to unidirectional rotation of the central rotor D and F subunits relative to the A(3)B(3) cylinder. In this study, we analyzed the rotation kinetics of V(1) in detail. At low ATP concentrations, the D subunit rotated stepwise, pausing every 120 degrees . The dwell time between steps revealed that V(1) consumes one ATP per 120 degrees step. V(1) generated torque of approximately 35 pN nm, slightly lower than the approximately 46 pN nm measured for F(1). Noticeably, the angles for both ATP cleavage and binding were apparently the same in V(1), in sharp contrast to F(1), which cleaves ATP at 80 degrees posterior to the binding of ATP. Thus, the mechanochemical cycle of V(1) has marked differences to that of F(1).
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Affiliation(s)
- Hiromi Imamura
- ATP System Project, Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Midori-ku, Yokohama
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Gerle C, Tani K, Yokoyama K, Tamakoshi M, Yoshida M, Fujiyoshi Y, Mitsuoka K. Two-dimensional crystallization and analysis of projection images of intact Thermus thermophilus V-ATPase. J Struct Biol 2005; 153:200-6. [PMID: 16377206 DOI: 10.1016/j.jsb.2005.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 10/31/2005] [Accepted: 11/07/2005] [Indexed: 11/24/2022]
Abstract
H(+)-ATPase/synthases are membrane-bound rotary nanomotors that are essential for energy conversion in nearly all life forms. A member of the family of the vacuolar-type ATPases (V-ATPases) from Thermus thermophilus, sometimes also termed A-type ATPase, was purified to homogeneity and subjected to two-dimensional (2D) crystallization trials. A novel approach to the 2D crystallization of unstable complexes yielded densely packed sheets of V-ATPase, exhibiting crystalline arrays. Aggregation of the V-ATPase under acidic conditions during reconstitution circumvented the continuous dissociation of the whole complex into the V(1) and V(o) domains. The resulting three-dimensional aggregates were converted into 2D sheets by the use of a basic buffer, and after a short annealing cycle, ordered arrays of up to 1.5 microm diameter appeared. Fourier transforms calculated from micrographs taken from the negatively stained sample showed diffraction spots to a resolution of 23A. The Fourier transforms of the untilted images revealed unit-cell dimensions of a=232A, b=132A, and gamma=90 degrees , and a projection map was calculated by merging 11 images. The most probable molecular packing suggests p22(1)2(1) symmetry of the crystals and dimer contacts between the V(1) domains.
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Affiliation(s)
- Christoph Gerle
- Department of Biophysics, Faculty of Science, Kyoto University, Oiwake, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
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