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Adem GD, Roy SJ, Huang Y, Chen ZH, Wang F, Zhou M, Bowman JP, Holford P, Shabala S. Expressing Arabidopsis thaliana V-ATPase subunit C in barley (Hordeum vulgare) improves plant performance under saline condition by enabling better osmotic adjustment. FUNCTIONAL PLANT BIOLOGY : FPB 2017; 44:1147-1159. [PMID: 32480640 DOI: 10.1071/fp17133] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/28/2017] [Indexed: 06/11/2023]
Abstract
Salinity is a global problem affecting agriculture that results in an estimated US$27 billion loss in revenue per year. Overexpression of vacuolar ATPase subunits has been shown to be beneficial in improving plant performance under saline conditions. Most studies, however, have not shown whether overexpression of genes encoding ATPase subunits results in improvements in grain yield, and have not investigated the physiological mechanisms behind the improvement in plant growth. In this study, we constitutively expressed Arabidopsis Vacuolar ATPase subunit C (AtVHA-C) in barley. Transgenic plants were assessed for agronomical and physiological characteristics, such as fresh and dry biomass, leaf pigment content, stomatal conductance, grain yield, and leaf Na+ and K+ concentration, when grown in either 0 or 300mM NaCl. When compared with non-transformed barley, AtVHA-C expressing barley lines had a smaller reduction in both biomass and grain yield under salinity stress. The transgenic lines accumulated Na+ and K+ in leaves for osmotic adjustment. This in turn saves energy consumed in the synthesis of organic osmolytes that otherwise would be needed for osmotic adjustment.
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Affiliation(s)
- Getnet D Adem
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Stuart J Roy
- Australian Centre for Plant Functional Genomics, Private Mail Bag 1, Glen Osmond, SA 5064, Australia
| | - Yuqing Huang
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
| | - Zhong-Hua Chen
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
| | - Feifei Wang
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Meixue Zhou
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - John P Bowman
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Paul Holford
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
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2
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Rotating with the brakes on and other unresolved features of the vacuolar ATPase. Biochem Soc Trans 2017; 44:851-5. [PMID: 27284051 PMCID: PMC4900747 DOI: 10.1042/bst20160043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Indexed: 12/31/2022]
Abstract
The rotary ATPase family comprises the ATP synthase (F-ATPase), vacuolar ATPase (V-ATPase) and archaeal ATPase (A-ATPase). These either predominantly utilize a proton gradient for ATP synthesis or use ATP to produce a proton gradient, driving secondary transport and acidifying organelles. With advances in EM has come a significant increase in our understanding of the rotary ATPase family. Following the sub nm resolution reconstructions of both the F- and V-ATPases, the secondary structure organization of the elusive subunit a has now been resolved, revealing a novel helical arrangement. Despite these significant developments in our understanding of the rotary ATPases, there are still a number of unresolved questions about the mechanism, regulation and overall architecture, which this mini-review aims to highlight and discuss.
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3
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Balakrishna AM, Manimekalai MSS, Grüber G. Protein-protein interactions within the ensemble, eukaryotic V-ATPase, and its concerted interactions with cellular machineries. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 119:84-93. [PMID: 26033199 DOI: 10.1016/j.pbiomolbio.2015.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 11/27/2022]
Abstract
The V1VO-ATPase (V-ATPase) is the important proton-pump in eukaryotic cells, responsible for pH-homeostasis, pH-sensing and amino acid sensing, and therefore essential for cell growths and metabolism. ATP-cleavage in the catalytic A3B3-hexamer of V1 has to be communicated via several so-called central and peripheral stalk units to the proton-pumping VO-part, which is membrane-embedded. A unique feature of V1VO-ATPase regulation is its reversible disassembly of the V1 and VO domain. Actin provides a network to hold the V1 in proximity to the VO, enabling effective V1VO-assembly to occur. Besides binding to actin, the 14-subunit V-ATPase interacts with multi-subunit machineries to form cellular sensors, which regulate the pH in cellular compartments or amino acid signaling in lysosomes. Here we describe a variety of subunit-subunit interactions within the V-ATPase enzyme during catalysis and its protein-protein assembling with key cellular machineries, essential for cellular function.
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Affiliation(s)
- Asha Manikkoth Balakrishna
- Nanyang Technological University, Division of Structural Biology and Biochemistry, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Malathy Sony Subramanian Manimekalai
- Nanyang Technological University, Division of Structural Biology and Biochemistry, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Gerhard Grüber
- Nanyang Technological University, Division of Structural Biology and Biochemistry, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore.
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4
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5
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Zhou M, Politis A, Davies R, Liko I, Wu KJ, Stewart AG, Stock D, Robinson CV. Ion mobility-mass spectrometry of a rotary ATPase reveals ATP-induced reduction in conformational flexibility. Nat Chem 2014; 6:208-215. [PMID: 24557135 PMCID: PMC4067995 DOI: 10.1038/nchem.1868] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 01/08/2014] [Indexed: 12/20/2022]
Abstract
Rotary ATPases play fundamental roles in energy conversion as their catalytic rotation is associated with interdomain fluctuations and heterogeneity of conformational states. Using ion mobility mass spectrometry we compared the conformational dynamics of the intact ATPase from Thermus thermophilus with those of its membrane and soluble subcomplexes. Our results define regions with enhanced flexibility assigned to distinct subunits within the overall assembly. To provide a structural context for our experimental data we performed molecular dynamics simulations and observed conformational changes of the peripheral stalks that reflect their intrinsic flexibility. By isolating complexes at different phases of cell growth and manipulating nucleotides, metal ions and pH during isolation, we reveal differences that can be related to conformational changes in the Vo complex triggered by ATP binding. Together these results implicate nucleotides in modulating flexibility of the stator components and uncover mechanistic detail that underlies operation and regulation in the context of the holoenzyme.
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Affiliation(s)
- Min Zhou
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK
| | - Argyris Politis
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK
| | - Roberta Davies
- The Victor Chang Cardiac Research Institute, Darlinghurst NSW 2010, Australia
- The University of New South Wales, Sydney NSW 2052, Australia
| | - Idlir Liko
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK
| | - Kuan-Jung Wu
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK
| | - Alastair G Stewart
- The Victor Chang Cardiac Research Institute, Darlinghurst NSW 2010, Australia
- The University of New South Wales, Sydney NSW 2052, Australia
| | - Daniela Stock
- The Victor Chang Cardiac Research Institute, Darlinghurst NSW 2010, Australia
- The University of New South Wales, Sydney NSW 2052, Australia
| | - Carol V Robinson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK
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6
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Marshansky V, Rubinstein JL, Grüber G. Eukaryotic V-ATPase: novel structural findings and functional insights. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:857-79. [PMID: 24508215 DOI: 10.1016/j.bbabio.2014.01.018] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 12/25/2013] [Accepted: 01/27/2014] [Indexed: 02/06/2023]
Abstract
The eukaryotic V-type adenosine triphosphatase (V-ATPase) is a multi-subunit membrane protein complex that is evolutionarily related to F-type adenosine triphosphate (ATP) synthases and A-ATP synthases. These ATPases/ATP synthases are functionally conserved and operate as rotary proton-pumping nano-motors, invented by Nature billions of years ago. In the first part of this review we will focus on recent structural findings of eukaryotic V-ATPases and discuss the role of different subunits in the function of the V-ATPase holocomplex. Despite structural and functional similarities between rotary ATPases, the eukaryotic V-ATPases are the most complex enzymes that have acquired some unconventional cellular functions during evolution. In particular, the novel roles of V-ATPases in the regulation of cellular receptors and their trafficking via endocytotic and exocytotic pathways were recently uncovered. In the second part of this review we will discuss these unique roles of V-ATPases in modulation of function of cellular receptors, involved in the development and progression of diseases such as cancer and diabetes as well as neurodegenerative and kidney disorders. Moreover, it was recently revealed that the V-ATPase itself functions as an evolutionarily conserved pH sensor and receptor for cytohesin-2/Arf-family GTP-binding proteins. Thus, in the third part of the review we will evaluate the structural basis for and functional insights into this novel concept, followed by the analysis of the potentially essential role of V-ATPase in the regulation of this signaling pathway in health and disease. Finally, future prospects for structural and functional studies of the eukaryotic V-ATPase will be discussed.
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Affiliation(s)
- Vladimir Marshansky
- Center for Systems Biology, Program in Membrane Biology, Division of Nephrology, Simches Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA; Kadmon Pharmaceuticals Corporation, Alexandria Center for Life Science, 450 East 29th Street, New York, NY 10016, USA.
| | - John L Rubinstein
- Molecular Structure and Function Program, The Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Gerhard Grüber
- Nanyang Technological University, Division of Structural Biology and Biochemistry, School of Biological Sciences, Singapore 637551, Republic of Singapore; Bioinformatics Institute, A(⁎)STAR, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
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7
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Low-resolution structure of the soluble domain GPAA1 (yGPAA170-247) of the glycosylphosphatidylinositol transamidase subunit GPAA1 from Saccharomyces cerevisiae. Biosci Rep 2013; 33:e00033. [PMID: 23458223 PMCID: PMC3610296 DOI: 10.1042/bsr20120107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The GPI (glycosylphosphatidylinositol) transamidase complex catalyses the attachment of GPI anchors to eukaryotic proteins in the lumen of ER (endoplasmic reticulum). The Saccharomyces cerevisiae GPI transamidase complex consists of the subunits yPIG-K (Gpi8p), yPIG-S (Gpi17p), yPIG-T (Gpi16p), yPIG-U (CDC91/GAB1) and yGPAA1. We present the production of the two recombinant proteins yGPAA170–247 and yGPAA170–339 of the luminal domain of S. cerevisiae GPAA1, covering the amino acids 70–247 and 70–339 respectively. The secondary structural content of the stable and monodisperse yGPAA170–247 has been determined to be 28% α-helix and 27% β-sheet. SAXS (small-angle X-ray scattering) data showed that yGPAA170–247 has an Rg (radius of gyration) of 2.72±0.025 nm and Dmax (maximum dimension) of 9.14 nm. These data enabled the determination of the two domain low-resolution solution structure of yGPAA170–247. The large elliptical shape of yGPAA170–247 is connected via a short stalk to the smaller hook-like domain of 0.8 nm in length and 3.5 nm in width. The topological arrangement of yGPAA170–247 will be discussed together with the recently determined low-resolution structures of yPIG-K24–337 and yPIG-S38–467 from S. cerevisiae in the GPI transamidase complex.
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8
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Basak S, Lim J, Manimekalai MSS, Balakrishna AM, Grüber G. Crystal and NMR structures give insights into the role and dynamics of subunit F of the eukaryotic V-ATPase from Saccharomyces cerevisiae. J Biol Chem 2013; 288:11930-9. [PMID: 23476018 DOI: 10.1074/jbc.m113.461533] [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
Subunit F of V-ATPases is proposed to undergo structural alterations during catalysis and reversible dissociation from the V1VO complex. Recently, we determined the low resolution structure of F from Saccharomyces cerevisiae V-ATPase, showing an N-terminal egg shape, connected to a C-terminal hook-like segment via a linker region. To understand the mechanistic role of subunit F of S. cerevisiae V-ATPase, composed of 118 amino acids, the crystal structure of the major part of F, F(1-94), was solved at 2.3 Å resolution. The structural features were confirmed by solution NMR spectroscopy using the entire F subunit. The eukaryotic F subunit consists of the N-terminal F(1-94) domain with four-parallel β-strands, which are intermittently surrounded by four α-helices, and the C terminus, including the α5-helix encompassing residues 103 to 113. Two loops (26)GQITPETQEK(35) and (60)ERDDI(64) are described to be essential in mechanistic processes of the V-ATPase enzyme. The (26)GQITPETQEK(35) loop becomes exposed when fitted into the recently determined EM structure of the yeast V1VO-ATPase. A mechanism is proposed in which the (26)GQITPETQEK(35) loop of subunit F and the flexible C-terminal domain of subunit H move in proximity, leading to an inhibitory effect of ATPase activity in V1. Subunits D and F are demonstrated to interact with subunit d. Together with NMR dynamics, the role of subunit F has been discussed in the light of its interactions in the processes of reversible disassembly and ATP hydrolysis of V-ATPases by transmitting movements of subunit d and H of the VO and V1 sector, respectively.
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Affiliation(s)
- Sandip Basak
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Singapore
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9
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Rahman S, Yamato I, Saijo S, Mizutani K, Ishizuka-Katsura Y, Ohsawa N, Terada T, Shirouzu M, Yokoyama S, Iwata S, Murata T. Biochemical and biophysical properties of interactions between subunits of the peripheral stalk region of human V-ATPase. PLoS One 2013; 8:e55704. [PMID: 23409023 PMCID: PMC3569449 DOI: 10.1371/journal.pone.0055704] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 12/28/2012] [Indexed: 11/18/2022] Open
Abstract
Peripheral stalk subunits of eukaryotic or mammalian vacuolar ATPases (V-ATPases) play key roles in regulating its assembly and disassembly. In a previous study, we purified several subunits and their isoforms of the peripheral stalk region of Homo sapiens (human) V-ATPase; such as C1, E1G1, H, and the N-terminal cytoplasmic region of V(o), a1. Here, we investigated the in vitro binding interactions of the subunits at the stalk region and measured their specific affinities. Surface plasmon resonance experiments revealed that the subunit C1 binds the E1G1 heterodimer with both high and low affinities (2.8 nM and 1.9 µM, respectively). In addition, an E1G1-H complex can be formed with high affinity (48 nM), whereas affinities of other subunit pairs appeared to be low (∼0.21-3.0 µM). The putative ternary complex of C1-H-E1G1 was not much strong on co-incubation of these subunits, indicating that the two strong complexes of C1-E1G1 and H-E1G1 in cooperation with many other weak interactions may be sufficiently strong enough to withstand the torque of rotation during catalysis. We observed a partially stable quaternary complex (consisting of E1G1, C1, a1(NT), and H subunits) resulting from discrete peripheral subunit interactions stabilizing the complex through their intrinsic affinities. No binding was observed in the absence of E1G1 (using only H, C1, and a1(NT)); therefore, it is likely that, in vivo, the E1G1 heterodimer has a significant role in the initiation of subunit assembly. Multiple interactions of variable affinity in the stalk region may be important to the mechanism of reversible dissociation of the intact V-ATPase.
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Affiliation(s)
- Suhaila Rahman
- Department of Biological Science and Technology, Tokyo University of Science, Chiba, Japan.
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10
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Pérez-Sayáns M, Suárez-Peñaranda JM, Barros-Angueira F, Diz PG, Gándara-Rey JM, García-García A. An update in the structure, function, and regulation of V-ATPases: the role of the C subunit. BRAZ J BIOL 2012; 72:189-98. [PMID: 22437401 DOI: 10.1590/s1519-69842012000100023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 02/23/2011] [Indexed: 11/22/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) are present in specialized proton secretory cells in which they pump protons across the membranes of various intracellular organelles and across the plasma membrane. The proton transport mechanism is electrogenic and establishes an acidic pH and a positive transmembrane potential in these intracellular and extracellular compartments. V-ATPases have been found to be practically identical in terms of the composition of their subunits in all eukaryotic cells. They have two distinct structures: a peripheral catalytic sector (V1) and a hydrophobic membrane sector (V0) responsible for driving protons. V-ATPase activity is regulated by three different mechanisms, which control pump density, association/dissociation of the V1 and V0 domains, and secretory activity. The C subunit is a 40-kDa protein located in the V1 domain of V-ATPase. The protein is encoded by the ATP6V1C gene and is located at position 22 of the long arm of chromosome 8 (8q22.3). The C subunit has very important functions in terms of controlling the regulation of the reversible dissociation of V-ATPases.
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Affiliation(s)
- M Pérez-Sayáns
- Faculty of Medicine and Dentistry, Santiago de Compostela, Spain
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11
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Rishikesan S, Grüber G. Structural elements of the C-terminal domain of subunit E (E₁₃₃₋₂₂₂) from the Saccharomyces cerevisiae V₁V₀ ATPase determined by solution NMR spectroscopy. J Bioenerg Biomembr 2011; 43:447-55. [PMID: 21826517 DOI: 10.1007/s10863-011-9379-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 07/15/2011] [Indexed: 01/08/2023]
Abstract
Subunit E of the vacuolar ATPase (V-ATPase) contains an N-terminal extended α helix (Rishikesan et al. J Bioenerg Biomembr 43:187-193, 2011) and a globular C-terminal part that is predicted to consist of a mixture of α-helices and β-sheets (Grüber et al. Biochem Biophys Res Comm 298:383-391, 2002). Here we describe the production, purification and 2D structure of the C-terminal segment E₁₃₃₋₂₂₂ of subunit E from Saccharamyces cerevisiae V-ATPase in solution based on the secondary structure calculation from NMR spectroscopy studies. E₁₃₃₋₂₂₂ consists of four β-strands, formed by the amino acids from K136-V139, E170-V173, G186-V189, D195-E198 and two α-helices, composed of the residues from R144-A164 and T202-I218. The sheets and helices are arranged as β1:α1:β2:β3:β4:α2, which are connected by flexible loop regions. These new structural details of subunit E are discussed in the light of the structural arrangements of this subunit inside the V₁- and V₁V₀ ATPase.
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Affiliation(s)
- Sankaranarayanan Rishikesan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
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12
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Grüber A, Gunalan K, Ramalingam JK, Manimekalai MSS, Grüber G, Preiser PR. Structural characterization of the erythrocyte binding domain of the reticulocyte binding protein homologue family of Plasmodium yoelii. Infect Immun 2011; 79:2880-8. [PMID: 21482683 PMCID: PMC3191949 DOI: 10.1128/iai.01326-10] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 03/28/2011] [Indexed: 11/20/2022] Open
Abstract
Invasion of the host cell by the malaria parasite is a key step for parasite survival and the only stage of its life cycle where the parasite is extracellular, and it is therefore a target for an antimalaria intervention strategy. Multiple members of the reticulocyte binding protein homologues (RH) family are found in all plasmodia and have been shown to bind to host red blood cells directly. In the study described here, we delineated the erythrocyte binding domain (EBD) of one member of the RH family, termed Py235, from Plasmodium yoelii. Moreover, we have obtained the low-resolution structure of the EBD using small-angle X-ray scattering. Comparison of the EDB structure to other characterized Plasmodium receptor binding domains suggests that there may be an overall structural conservation. These findings may help in developing new approaches to target receptor ligand interactions mediated by parasite proteins.
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Affiliation(s)
- Ardina Grüber
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Karthigayan Gunalan
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Jeya Kumar Ramalingam
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | | | - Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Peter R. Preiser
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
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13
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García-García A, Pérez-Sayáns M, Rodríguez MJ, Antúnez-López J, Barros-Angueira F, Somoza-Martín M, Gándara-Rey JM, Aguirre-Urízar JM. Immunohistochemical localization of C1 subunit of V-ATPase (ATPase C1) in oral squamous cell cancer and normal oral mucosa. Biotech Histochem 2011; 87:133-9. [DOI: 10.3109/10520295.2011.574647] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- A García-García
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
- University Hospital Complex of Santiago, Santiago de Compostela
| | - M Pérez-Sayáns
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
| | - MJ Rodríguez
- Department of Stomatology, University of the Basque Country EHU,
Leioa, Vizcaya
| | - J Antúnez-López
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
- University Hospital Complex of Santiago, Santiago de Compostela
| | - F Barros-Angueira
- Galician Public Foundation for Genomic Medicine, Santiago de Compostela, Spain
| | - M Somoza-Martín
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
| | - JM Gándara-Rey
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
| | - JM Aguirre-Urízar
- Department of Stomatology, University of the Basque Country EHU,
Leioa, Vizcaya
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14
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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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15
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Basak S, Gayen S, Thaker YR, Manimekalai MSS, Roessle M, Hunke C, Grüber G. Solution structure of subunit F (Vma7p) of the eukaryotic V(1)V(O) ATPase from Saccharomyces cerevisiae derived from SAXS and NMR spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:360-8. [PMID: 20840841 DOI: 10.1016/j.bbamem.2010.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 09/03/2010] [Accepted: 09/07/2010] [Indexed: 11/26/2022]
Abstract
Vacuolar ATPases use the energy derived from ATP hydrolysis, catalyzed in the A(3)B(3) sector of the V(1) ATPase to pump protons via the membrane-embedded V(O) sector. The energy coupling between the two sectors occurs via the so-called central stalk, to which subunit F does belong. Here we present the first low resolution structure of recombinant subunit F (Vma7p) of a eukaryotic V-ATPase from Saccharomyces cerevisiae, analyzed by small angle X-ray scattering (SAXS). The protein is divided into a 5.5nm long egg-like shaped region, connected via a 1.5nm linker to a hook-like segment at one end. Circular dichroism spectroscopy revealed that subunit F comprises of 43% α-helix, 32% β-sheet and a 25% random coil arrangement. To determine the localization of the N- and C-termini in the protein, the C-terminal truncated form of F, F(1-94) was produced and analyzed by SAXS. Comparison of the F(1-94) shape with the one of subunit F showed the missing hook-like region in F(1-94), supported by the decreased D(max) value of F(1-94) (7.0nm), and indicating that the hook-like region consists of the C-terminal residues. The NMR solution structure of the C-terminal peptide, F(90-116), was solved, displaying an α-helical region between residues 103 and 113. The F(90-116) solution structure fitted well in the hook-like region of subunit F. Finally, the arrangement of subunit F within the V(1) ATPase is discussed.
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Affiliation(s)
- Sandip Basak
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
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16
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Hildenbrand ZL, Molugu SK, Stock D, Bernal RA. The C-H peripheral stalk base: a novel component in V1-ATPase assembly. PLoS One 2010; 5:e12588. [PMID: 20838636 PMCID: PMC2933246 DOI: 10.1371/journal.pone.0012588] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 08/10/2010] [Indexed: 11/18/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) are molecular machines responsible for creating electrochemical gradients and preserving pH-dependent cellular compartments by way of proton translocation across the membrane. V-ATPases employ a dynamic rotary mechanism that is driven by ATP hydrolysis and the central rotor stalk. Regulation of this rotational catalysis is the result of a reversible V1Vo-domain dissociation that is required to preserve ATP during instances of cellular starvation. Recently the method by which the free V1-ATPase abrogates the hydrolytic breakdown of ATP upon dissociating from the membrane has become increasingly clear. In this instance the central stalk subunit F adopts an extended conformation to engage in a bridging interaction tethering the rotor and stator components together. However, the architecture by which this mechanism is stabilized has remained ambiguous despite previous work. In an effort to elucidate the method by which the rotational catalysis is maintained, the architecture of the peripheral stalks and their respective binding interactions was investigated using cryo-electron microscopy. In addition to confirming the bridging interaction exuded by subunit F for the first time in a eukaryotic V-ATPase, subunits C and H are seen interacting with one another in a tight interaction that provides a base for the three EG peripheral stalks. The formation of a CE3G3H sub-assembly appears to be unique to the dissociated V-ATPase and highlights the stator architecture in addition to revealing a possible intermediate in the assembly mechanism of the free V1-ATPase.
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Affiliation(s)
- Zacariah L. Hildenbrand
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Sudheer K. Molugu
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Daniela Stock
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
- Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Ricardo A. Bernal
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
- * E-mail:
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17
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The NMR solution structure of subunit G (G(61)(-)(101)) of the eukaryotic V1VO ATPase from Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:1961-8. [PMID: 20599533 DOI: 10.1016/j.bbamem.2010.06.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 06/14/2010] [Accepted: 06/15/2010] [Indexed: 11/20/2022]
Abstract
Subunit G is an essential stalk subunit of the eukaryotic proton pump V(1)V(O) ATPase. Previously the structure of the N-terminal region, G(1)(-)(59), of the 13kDa subunit G was solved at higher resolution. Here solution NMR was performed to determine the structure of the recombinant C-terminal region (G(61)(-)(101)) of subunit G of the Saccharomyces cerevisiae V(1)V(O) ATPase. The protein forms an extended alpha-helix between residues 64 and 100, whereby the first five- and the last residues of G(61)(-)(101) are flexible. The surface charge distribution of G(61)(-)(101) reveals an amphiphilic character at the C-terminus due to positive and negative charge distribution at one side and a hydrophobic surface on the opposite side of the structure. The hydrophobic surface pattern is mainly formed by alanine residues. The alanine residues 72, 74 and 81 were exchanged by a single cysteine in the entire subunit G. Cysteines at positions 72 and 81 showed disulfide formation. In contrast, no crosslink could be formed for the mutant Ala74Cys. Together with the recently determined NMR solution structure of G(1)(-)(59), the presented solution structure of G(61)(-)(101) enabled us to present a first structural model of the entire subunit G of the S. cerevisiae V(1)V(O) ATPase.
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18
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Oot RA, Wilkens S. Domain characterization and interaction of the yeast vacuolar ATPase subunit C with the peripheral stator stalk subunits E and G. J Biol Chem 2010; 285:24654-64. [PMID: 20529855 DOI: 10.1074/jbc.m110.136960] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The proton pumping activity of the eukaryotic vacuolar ATPase (V-ATPase) is regulated by a unique mechanism that involves reversible enzyme dissociation. In yeast, under conditions of nutrient depletion, the soluble catalytic V(1) sector disengages from the membrane integral V(o), and at the same time, both functional units are silenced. Notably, during enzyme dissociation, a single V(1) subunit, C, is released into the cytosol. The affinities of the other V(1) and V(o) subunits for subunit C are therefore of particular interest. The C subunit crystal structure shows that the subunit is elongated and dumbbell-shaped with two globular domains (C(head) and C(foot)) separated by a flexible helical neck region (Drory, O., Frolow, F., and Nelson, N. (2004) EMBO Rep. 5, 1148-1152). We have recently shown that subunit C is bound in the V(1)-V(o) interface where the subunit is in contact with two of the three peripheral stators (subunit EG heterodimers): one via C(head) and one via C(foot) (Zhang, Z., Zheng, Y., Mazon, H., Milgrom, E., Kitagawa, N., Kish-Trier, E., Heck, A. J., Kane, P. M., and Wilkens, S. (2008) J. Biol. Chem. 283, 35983-35995). In vitro, however, subunit C binds only one EG heterodimer (Féthière, J., Venzke, D., Madden, D. R., and Böttcher, B. (2005) Biochemistry 44, 15906-15914), implying that EG has different affinities for the two domains of the C subunit. To determine which subunit C domain binds EG with high affinity, we have generated C(head) and C(foot) and characterized their interaction with subunit EG heterodimer. Our findings indicate that the high affinity site for EGC interaction is C(head). In addition, we provide evidence that the EGC(head) interaction greatly stabilizes EG heterodimer.
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Affiliation(s)
- Rebecca A Oot
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210, USA
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19
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Rishikesan S, Thaker YR, Priya R, Gayen S, Manimekalai MSS, Hunke C, Grüber G. Spectroscopical identification of residues of subunit G of the yeast V-ATPase in its connection with subunit E. Mol Membr Biol 2009; 25:400-10. [DOI: 10.1080/09687680802183434] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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20
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Grüber G, Marshansky V. New insights into structure-function relationships between archeal ATP synthase (A1A0) and vacuolar type ATPase (V1V0). Bioessays 2008; 30:1096-109. [PMID: 18937357 DOI: 10.1002/bies.20827] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Adenosine triphosphate, ATP, is the energy currency of living cells. While ATP synthases of archae and ATP synthases of pro- and eukaryotic organisms operate as energy producers by synthesizing ATP, the eukaryotic V-ATPase hydrolyzes ATP and thus functions as energy transducer. These enzymes share features like the hydrophilic catalytic- and the membrane-embedded ion-translocating sector, allowing them to operate as nano-motors and to transform the transmembrane electrochemical ion gradient into ATP or vice versa. Since archaea are rooted close to the origin of life, the A-ATP synthase is probably more similar in its composition and function to the "original" enzyme, invented by Nature billion years ago. On the contrary, the V-ATPases have acquired specific structural, functional and regulatory features during evolution. This review will summarize the current knowledge on the structure, mechanism and regulation of A-ATP synthases and V-ATPases. The importance of V-ATPase in pathophysiology of diseases will be discussed.
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Affiliation(s)
- Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore.
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21
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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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Abstract
Several flaviviruses are important human pathogens, including dengue virus, a disease against which neither a vaccine nor specific antiviral therapies currently exist. During infection, the flavivirus RNA genome is translated into a polyprotein, which is cleaved into several components. Nonstructural protein 3 (NS3) carries out enzymatic reactions essential for viral replication, including proteolysis of the polyprotein through its serine protease N-terminal domain, with a segment of 40 residues from the NS2B protein acting as a cofactor. The ATPase/helicase domain is located at the C terminus of NS3. Atomic structures are available for these domains separately, but a molecular view of the full-length flavivirus NS3 polypeptide is still lacking. We report a crystallographic structure of a complete NS3 molecule fused to 18 residues of the NS2B cofactor at a resolution of 3.15 A. The relative orientation between the protease and helicase domains is drastically different than the single-chain NS3-NS4A molecule from hepatitis C virus, which was caught in the act of cis cleavage at the NS3-NS4A junction. Here, the protease domain sits beneath the ATP binding site, giving the molecule an elongated shape. The domain arrangement found in the crystal structure fits nicely into an envelope determined ab initio using small-angle X-ray scattering experiments in solution, suggesting a stable molecular conformation. We propose that a basic patch located at the surface of the protease domain increases the affinity for nucleotides and could also participate in RNA binding, explaining the higher unwinding activity of the full-length enzyme compared to that of the isolated helicase domain.
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23
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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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24
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Schäfer I, Rössle M, Biuković G, Müller V, Grüber G. Structural and functional analysis of the coupling subunit F in solution and topological arrangement of the stalk domains of the methanogenic A1AO ATP synthase. J Bioenerg Biomembr 2006; 38:83-92. [PMID: 16897437 DOI: 10.1007/s10863-006-9015-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 04/07/2006] [Indexed: 11/28/2022]
Abstract
The first low-resolution shape of subunit F of the A(1)A(O) ATP synthase from the archaeon Methanosarcina mazei Gö1 in solution was determined by small angle X-ray scattering. Independent to the concentration used, the protein is monomeric and has an elongated shape, divided in a main globular part with a length of about 4.5 nm, and a hook-like domain of about 3.0 nm in length. The subunit-subunit interaction of subunit F inside the A(1)A(O) ATP synthase in the presence of 1-ethyl-3-(dimethylaminopropyl)-carbodiimide EDC was studied as a function of nucleotide binding, demonstrating movements of subunits F relative to the nucleotide-binding subunit B. Furthermore, in the intact A(1)A(O) complex, crosslinking of subunits D-E, A-H and A-B-D was obtained and the peptides, involved, were analyzed by MALDI-TOF mass spectrometry. Based on these data the surface of contact of B-F could be mapped in the high-resolution structure of subunit B of the A(1)A(O) ATP synthase.
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Affiliation(s)
- Ingmar Schäfer
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
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25
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Müller V, Lemker T, Lingl A, Weidner C, Coskun U, Grüber G. Bioenergetics of archaea: ATP synthesis under harsh environmental conditions. J Mol Microbiol Biotechnol 2006; 10:167-80. [PMID: 16645313 DOI: 10.1159/000091563] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Archaea are a heterogeneous group of microorganisms that often thrive under harsh environmental conditions such as high temperatures, extreme pHs and high salinity. As other living cells, they use chemiosmotic mechanisms along with substrate level phosphorylation to conserve energy in form of ATP. Because some archaea are rooted close to the origin in the tree of life, these unusual mechanisms are considered to have developed very early in the history of life and, therefore, may represent first energy-conserving mechanisms. A key component in cellular bioenergetics is the ATP synthase. The enzyme from archaea represents a new class of ATPases, the A1A0 ATP synthases. They are composed of two domains that function as a pair of rotary motors connected by a central and peripheral stalk(s). The structure of the chemically-driven motor (A1) was solved by small-angle X-ray scattering in solution, and the structure of the first A1A0 ATP synthases was obtained recently by single particle analyses. These studies revealed novel structural features such as a second peripheral stalk and a collar-like structure. In addition, the membrane-embedded electrically-driven motor (A0) is very different in archaea with sometimes novel, exceptional subunit composition and coupling stoichiometries that may reflect the differences in energy-conserving mechanisms as well as adaptation to temperatures at or above 100 degrees C.
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Affiliation(s)
- V Müller
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Campus Riedberg, Frankfurt a. Main, Germany.
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26
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Walker JE, Dickson VK. The peripheral stalk of the mitochondrial ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:286-96. [PMID: 16697972 DOI: 10.1016/j.bbabio.2006.01.001] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Accepted: 01/04/2006] [Indexed: 12/23/2022]
Abstract
The peripheral stalk of F-ATPases is an essential component of these enzymes. It extends from the membrane distal point of the F1 catalytic domain along the surface of the F1 domain with subunit a in the membrane domain. Then, it reaches down some 45 A to the membrane surface, and traverses the membrane, where it is associated with the a-subunit. Its role is to act as a stator to hold the catalytic alpha3beta3 subcomplex and the a-subunit static relative to the rotary element of the enzyme, which consists of the c-ring in the membrane and the attached central stalk. The central stalk extends up about 45 A from the membrane surface and then penetrates into the alpha3beta3 subcomplex along its central axis. The mitochondrial peripheral stalk is an assembly of single copies of the oligomycin sensitivity conferral protein (the OSCP) and subunits b, d and F6. In the F-ATPase in Escherichia coli, its composition is simpler, and it consists of a single copy of the delta-subunit with two copies of subunit b. In some bacteria and in chloroplasts, the two copies of subunit b are replaced by single copies of the related proteins b and b' (known as subunits I and II in chloroplasts). As summarized in this review, considerable progress has been made towards establishing the structure and biophysical properties of the peripheral stalk in both the mitochondrial and bacterial enzymes. However, key issues are unresolved, and so our understanding of the role of the peripheral stalk and the mechanism of synthesis of ATP are incomplete.
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Affiliation(s)
- John E Walker
- The Medical Research Council Dunn Human Nutrition Unit, The Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 2XY, UK.
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27
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Hong-Hermesdorf A, Brüx A, Grüber A, Grüber G, Schumacher K. A WNK kinase binds and phosphorylates V-ATPase subunit C. FEBS Lett 2006; 580:932-9. [PMID: 16427632 DOI: 10.1016/j.febslet.2006.01.018] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 12/14/2005] [Accepted: 01/04/2006] [Indexed: 10/25/2022]
Abstract
WNK (with no lysine (K)) protein kinases are found in many eukaryotes and share a unique active site. Here, we report that a member of the Arabidopsis WNK family (AtWNK8) interacts with subunit C of the vacuolar H+-ATPase (V-ATPase) via a short C-terminal domain. AtWNK8 is shown to autophosphorylate intermolecularly and to phosphorylate Arabidopsis subunit C (AtVHA-C) at multiple sites as determined by MALDI-TOF MS analysis. Furthermore, we show that AtVHA-C and other V-ATPase subunits are phosphorylated when V1-complexes are used as substrates for AtWNK8. Taken together, our results provide evidence that V-ATPases are potential targets of WNK kinases and their associated signaling pathways.
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Affiliation(s)
- Anne Hong-Hermesdorf
- Universität Tübingen, ZMBP-Plant Physiology, Auf der Morgenstelle 1, 72076 Tübingen, Germany
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28
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Grüber G. Structural features and nucleotide-binding capability of the C subunit are integral to the regulation of the eukaryotic V1Vo ATPases. Biochem Soc Trans 2005; 33:883-5. [PMID: 16042619 DOI: 10.1042/bst0330883] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
V-ATPases (vacuolar ATPases) are responsible for acidification of intracellular compartments and, in certain cases, proton transport across the plasma membrane of eukaryotic cells. They are composed of a catalytic V1 sector, in which ATP hydrolysis takes place, and the Vo sector, which functions in proton conduction. The best established mechanism for regulating the V-ATPase activity in vivo involves reversible dissociation of the V1 and Vo domains, in which subunit C is intimately involved. In the last year, impressive progress has been made in elucidating the structure of the C subunit and its arrangement inside the V-ATPase. Nucleotide occupancy by subunit C, followed by conformational changes of this subunit has shed light on the mechanism of V-ATPase regulation.
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Affiliation(s)
- G Grüber
- Universität des Saarlandes, Fachrichtung 2.5-Biophysik, Universitätsbau 76, D-66421 Homburg, Germany.
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29
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Chaban YL, Juliano S, Boekema EJ, Grüber G. Interaction between subunit C (Vma5p) of the yeast vacuolar ATPase and the stalk of the C-depleted V1 ATPase from Manduca sexta midgut. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1708:196-200. [PMID: 15953476 DOI: 10.1016/j.bbabio.2005.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Revised: 01/26/2005] [Accepted: 02/02/2005] [Indexed: 11/21/2022]
Abstract
Projection maps of a V(1)-Vma5p hybrid complex, composed of subunit C (Vma5p) of Saccharomyces cerevisiae V-ATPase and the C-depleted V(1) from Manduca sexta, were determined from single particle electron microscopy. V(1)-Vma5p consists of a headpiece and an elongated wedgelike stalk with a 2.1x3.0 nm protuberance and a 9.5x7.5 globular domain, interpreted to include Vma5p. The interaction face of Vma5p in V(1) was explored by chemical modification experiments.
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Affiliation(s)
- Yuriy L Chaban
- Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
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30
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Armbrüster A, Hohn C, Hermesdorf A, Schumacher K, Börsch M, Grüber G. Evidence for major structural changes in subunit C of the vacuolar ATPase due to nucleotide binding. FEBS Lett 2005; 579:1961-7. [PMID: 15792803 DOI: 10.1016/j.febslet.2005.02.042] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 02/14/2005] [Accepted: 02/14/2005] [Indexed: 11/26/2022]
Abstract
The ability of subunit C of eukaryotic V-ATPases to bind ADP and ATP is demonstrated by photoaffinity labeling and fluorescence correlation spectroscopy (FCS). Quantitation of the photoaffinity and the FCS data indicate that the ATP-analogues bind more weakly to subunit C than the ADP-analogues. Site-directed mutagenesis and N-terminal sequencing of subunit C from Arabidopsis (VHA-C) and yeast (Vma5p) have been used to map the C-terminal region of subunit C as the nucleotide-binding site. Tryptophan fluorescence quenching and decreased susceptibility to tryptic digestion of subunit C after binding of different nucleotides provides evidence for structural changes in this subunit caused by nucleotide-binding.
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Affiliation(s)
- Andrea Armbrüster
- Universität des Saarlandes, Fachrichtung 2.5, Biophysik, Universitätsbau 76, D-66421 Homburg, Germany
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31
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Drory O, Frolow F, Nelson N. Crystal structure of yeast V-ATPase subunit C reveals its stator function. EMBO Rep 2005; 5:1148-52. [PMID: 15540116 PMCID: PMC1299189 DOI: 10.1038/sj.embor.7400294] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 10/12/2004] [Accepted: 10/13/2004] [Indexed: 11/08/2022] Open
Abstract
Vacuolar H(+)-ATPase (V-ATPase) has a crucial role in the vacuolar system of eukaryotic cells. It provides most of the energy required for transport systems that utilize the proton-motive force that is generated by ATP hydrolysis. Some, but not all, of the V-ATPase subunits are homologous to those of F-ATPase and the nonhomologous subunits determine the unique features of V-ATPase. We determined the crystal structure of V-ATPase subunit C (Vma5p), which does not show any homology with F-ATPase subunits, at 1.75 A resolution. The structural features suggest that subunit C functions as a flexible stator that holds together the catalytic and membrane sectors of the enzyme. A second crystal form that was solved at 2.9 A resolution supports the flexible nature of subunit C. These structures provide a framework for exploring the unique mechanistic features of V-ATPases.
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Affiliation(s)
- Omri Drory
- Department of Biochemistry, The George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, The George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nathan Nelson
- Department of Biochemistry, The George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
- Tel: +972 3 640 6017; Fax: +972 3 640 6018; E-mail:
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32
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Current awareness on yeast. Yeast 2005; 22:71-8. [PMID: 15685779 DOI: 10.1002/yea.1157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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33
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Lokanath NK, Ukita Y, Sugahara M, Kunishima N. Purification, crystallization and preliminary crystallographic analysis of the vacuole-type ATPase subunit E from Pyrococcus horikoshii OT3. Acta Crystallogr Sect F Struct Biol Cryst Commun 2005; 61:56-8. [PMID: 16508090 PMCID: PMC1952376 DOI: 10.1107/s1744309104026430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Accepted: 10/19/2004] [Indexed: 11/10/2022]
Abstract
The vacuole-type ATPases in eukaryotic cells translocate protons across various biological membranes including the vacuolar membrane by consuming ATP molecules. The E subunit of the multisubunit complex V-ATPase from Pyrococcus horikoshii OT3, which has a molecular weight of 22.88 kDa, has been cloned, overexpressed in Escherichia coli, purified and crystallized by the microbatch method using PEG 4000 as a precipitant at 296 K. A data set to 1.85 A resolution with 98.8% completeness and an Rmerge of 6.5% was collected from a single flash-cooled crystal using synchrotron radiation. The crystal belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 52.196, b = 55.317, c = 77.481 A, and is most likely to contain one molecule per asymmetric unit.
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Affiliation(s)
- Neratur K. Lokanath
- Highthroughput Factory, RIKEN Harima Institute at SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Yoko Ukita
- Highthroughput Factory, RIKEN Harima Institute at SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Mitsuaki Sugahara
- Highthroughput Factory, RIKEN Harima Institute at SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Naoki Kunishima
- Highthroughput Factory, RIKEN Harima Institute at SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148, Japan
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Vitavska O, Merzendorfer H, Wieczorek H. The V-ATPase Subunit C Binds to Polymeric F-actin as Well as to Monomeric G-actin and Induces Cross-linking of Actin Filaments. J Biol Chem 2005; 280:1070-6. [PMID: 15525650 DOI: 10.1074/jbc.m406797200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previously, we have shown that the V-ATPase holoenzyme as well as the V1 complex isolated from the midgut of the tobacco hornworm (Manduca sexta) exhibits the ability of binding to actin filaments via the V1 subunits B and C (Vitavska, O., Wieczorek, H., and Merzendorfer,H. (2003) J. Biol. Chem. 278, 18499-18505). Since the recombinant subunit C not only enhances actin binding of the V1 complex but also can bind separately to F-actin, we analyzed the interaction of recombinant subunit C with actin. We demonstrate that it binds not only to F-actin but also to monomeric G-actin. With dissociation constants of approximately 50 nm, the interaction exhibits a high affinity, and no difference could be observed between binding to ATP-G-actin or ADP-G-actin, respectively. Unlike other proteins such as members of the ADF/cofilin family, which also bind to G- as well as to F-actin, subunit C does not destabilize actin filaments. On the contrary, under conditions where the disassembly of F-actin into G-actin usually occurred, subunit C stabilized F-actin. In addition, it increased the initial rate of actin polymerization in a concentration-dependent manner and was shown to cross-link actin filaments to bundles of varying thickness. Apparently bundling is enabled by the existence of at least two actin-binding sites present in the N- and in the C-terminal halves of subunits C, respectively. Since subunit C has the possibility to dimerize or even to oligomerize, spacing between actin filaments could be variable in size.
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Affiliation(s)
- Olga Vitavska
- Department of Biology/Chemistry, Division of Animal Physiology, University of Osnabrück, 49069 Osnabrück, Germany
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