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Molecular characterization and transcriptional regulation of two types of H +-pyrophosphatases in the scuticociliate parasite Philasterides dicentrarchi. Sci Rep 2021; 11:8519. [PMID: 33875762 PMCID: PMC8055999 DOI: 10.1038/s41598-021-88102-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 04/08/2021] [Indexed: 02/02/2023] Open
Abstract
Proton-translocating inorganic pyrophosphatases (H+-PPases) are an ancient family of membrane bound enzymes that couple pyrophosphate (PPi) hydrolysis to H+ translocation across membranes. In this study, we conducted a molecular characterization of two isoenzymes (PdVP1 and PdVP2) located in respectively the alveolar sacs and in the membranes of the intracellular vacuoles of a scuticociliate parasite (Philasterides dicentrarchi) of farmed turbot. We analyzed the genetic expression of the isoenzymes after administration of antiparasitic drugs and after infection in the host. PdVP1 and PdVP2 are encoded by two genes of 2485 and 3069 bp, which respectively contain 3 and 11 exons and express proteins of 746 and 810 aa of molecular mass 78.9 and 87.6 kDa. Topological predictions from isoenzyme sequences indicate the formation of thirteen transmembrane regions (TMRs) for PdVP1 and seventeen TMRs for PdVP2. Protein structure modelling indicated that both isoenzymes are homodimeric, with three Mg2+ binding sites and an additional K+ binding site in PdVP2. The levels of identity and similarity between the isoenzyme sequences are respectively 33.5 and 51.2%. The molecular weights of the native proteins are 158 kDa (PdVP1) and 178 kDa (PdVP2). The isoenzyme sequences are derived from paralogous genes that form a monophyletic grouping with other ciliate species. Genetic expression of the isoenzymes is closely related to the acidification of alveolar sacs (PdVP1) and intracellular vacuoles (PdVP2): antiparasitic drugs inhibit transcription, while infection increases transcription of both isoenzymes. The study findings show that P. dicentrarchi possesses two isoenzymes with H+-PPase activity which are located in acidophilic cell compartment membranes and which are activated during infection in the host and are sensitive to antiparasitic drugs. The findings open the way to using molecular modelling to design drugs for the treatment of scuticociliatosis.
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Primo C, Pizzio GA, Yang J, Gaxiola RA, Scholz-Starke J, Hirschi KD. Plant proton pumping pyrophosphatase: the potential for its pyrophosphate synthesis activity to modulate plant growth. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:989-996. [PMID: 31081197 DOI: 10.1111/plb.13007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 05/09/2019] [Indexed: 05/25/2023]
Abstract
Cellular pyrophosphate (PPi) homeostasis is vital for normal plant growth and development. Plant proton-pumping pyrophosphatases (H+ -PPases) are enzymes with different tissue-specific functions related to the regulation of PPi homeostasis. Enhanced expression of plant H+ -PPases increases biomass and yield in different crop species. Here, we emphasise emerging studies utilising heterologous expression in yeast and plant vacuole electrophysiology approaches, as well as phylogenetic relationships and structural analysis, to showcase that the H+ -PPases possess a PPi synthesis function. We postulate this synthase activity contributes to modulating and promoting plant growth both in H+ -PPase-engineered crops and in wild-type plants. We propose a model where the PPi synthase activity of H+ -PPases maintains the PPi pool when cells adopt PPi-dependent glycolysis during high energy demands and/or low oxygen environments. We conclude by proposing experiments to further investigate the H+ -PPase-mediated PPi synthase role in plant growth.
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Affiliation(s)
- C Primo
- Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA
| | - G A Pizzio
- Center for Research in Agricultural Genomics, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
| | - J Yang
- Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA
| | - R A Gaxiola
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - J Scholz-Starke
- Institute of Biophysics, Consiglio Nazionale delle Ricerche, Genova, Italy
| | - K D Hirschi
- Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA
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Asaoka M, Segami S, Maeshima M. Identification of the critical residues for the function of vacuolar H+-pyrophosphatase by mutational analysis based on the 3D structure. ACTA ACUST UNITED AC 2014; 156:333-44. [DOI: 10.1093/jb/mvu046] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Seidel T, Siek M, Marg B, Dietz KJ. Energization of vacuolar transport in plant cells and its significance under stress. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 304:57-131. [PMID: 23809435 DOI: 10.1016/b978-0-12-407696-9.00002-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The plant vacuole is of prime importance in buffering environmental perturbations and in coping with abiotic stress caused by, for example, drought, salinity, cold, or UV. The large volume, the efficient integration in anterograde and retrograde vesicular trafficking, and the dynamic equipment with tonoplast transporters enable the vacuole to fulfill indispensible functions in cell biology, for example, transient and permanent storage, detoxification, recycling, pH and redox homeostasis, cell expansion, biotic defence, and cell death. This review first focuses on endomembrane dynamics and then summarizes the functions, assembly, and regulation of secretory and vacuolar proton pumps: (i) the vacuolar H(+)-ATPase (V-ATPase) which represents a multimeric complex of approximately 800 kDa, (ii) the vacuolar H(+)-pyrophosphatase, and (iii) the plasma membrane H(+)-ATPase. These primary proton pumps regulate the cytosolic pH and provide the driving force for secondary active transport. Carriers and ion channels modulate the proton motif force and catalyze uptake and vacuolar compartmentation of solutes and deposition of xenobiotics or secondary compounds such as flavonoids. ABC-type transporters directly energized by MgATP complement the transport portfolio that realizes the multiple functions in stress tolerance of plants.
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Affiliation(s)
- Thorsten Seidel
- Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Bielefeld, Germany.
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Kellosalo J, Kajander T, Kogan K, Pokharel K, Goldman A. The structure and catalytic cycle of a sodium-pumping pyrophosphatase. Science 2012; 337:473-6. [PMID: 22837527 DOI: 10.1126/science.1222505] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Membrane-integral pyrophosphatases (M-PPases) are crucial for the survival of plants, bacteria, and protozoan parasites. They couple pyrophosphate hydrolysis or synthesis to Na(+) or H(+) pumping. The 2.6-angstrom structure of Thermotoga maritima M-PPase in the resting state reveals a previously unknown solution for ion pumping. The hydrolytic center, 20 angstroms above the membrane, is coupled to the gate formed by the conserved Asp(243), Glu(246), and Lys(707) by an unusual "coupling funnel" of six α helices. Comparison with our 4.0-angstrom resolution structure of the product complex suggests that helix 12 slides down upon substrate binding to open the gate by a simple binding-change mechanism. Below the gate, four helices form the exit channel. Superimposing helices 3 to 6, 9 to 12, and 13 to 16 suggests that M-PPases arose through gene triplication.
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Affiliation(s)
- Juho Kellosalo
- Structural Biology and Biophysics Program, Institute of Biotechnology, Post Office Box 65, University of Helsinki, FIN-00014, Finland
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Façanha AR, Okorokova-Façanha AL. ATP synthesis catalyzed by a V-ATPase: an alternative pathway for energy conservation operating in plant vacuoles? PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2008; 14:195-203. [PMID: 23572887 PMCID: PMC3550615 DOI: 10.1007/s12298-008-0019-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The electrochemical H(+) gradient generated in tonoplast vesicles isolated from maize seeds was found to be able to drive the reversal of the catalytic cycle of both vacuolar H(+)-pumps (Façanha and de Meis, 1998). Here we describe the reversibility of the vacuolar V-type H(+)-ATPase (V-ATPase) even in the absence of the H(+) gradient in a water-Me2SO co-solvent mixture, resulting in net synthesis of [γ-(32)P]ATP from [(32)P]Pi and ADP. The water-Me2SO (5 to 20 %) media promoted inhibition of both PPi hydrolysis and synthesis reactions whereas it slightly affected the ATP hydrolysis and clearly stimulated the ATP synthesis, which was unaffected by uncoupling agents (FCCP, Triton X-100 or NH4 (+)). This effect of Me2SO on the ATP⇔(32)P exchange reaction seems to be related to a decrease of the apparent K m of the V-ATPase for Pi. The results are in accordance to the concept that the energetics of ATP synthesis catalysis depends on the solvation energies interacting in the enzyme microenvironment. A possible physiological significance of this phenomenon for the metabolism of desiccation-tolerant plant cells is discussed.
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Affiliation(s)
- Arnoldo Rocha Façanha
- />Laboratório de Biologia Celular & Tecidual, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000, Pq. California, Campos dos Goytacazes, RJ 28013-602 Brazil
| | - Anna Lvovna Okorokova-Façanha
- />Laboratório de Fisiologia & Bioquímica de Microrganismos, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000, Pq. California, Campos dos Goytacazes, RJ 28013-602 Brazil
- />Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000, Pq. California, Campos dos Goytacazes, RJ 28013-602 Brazil
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Hirono M, Nakanishi Y, Maeshima M. Identification of amino acid residues participating in the energy coupling and proton transport of Streptomyces coelicolor A3(2) H+-pyrophosphatase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:1401-11. [DOI: 10.1016/j.bbabio.2007.09.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2007] [Revised: 09/05/2007] [Accepted: 09/20/2007] [Indexed: 11/30/2022]
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Hsiao YY, Pan YJ, Hsu SH, Huang YT, Liu TH, Lee CH, Lee CH, Liu PF, Chang WC, Wang YK, Chien LF, Pan RL. Functional roles of arginine residues in mung bean vacuolar H+-pyrophosphatase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:965-73. [PMID: 17543272 DOI: 10.1016/j.bbabio.2007.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 04/26/2007] [Accepted: 04/27/2007] [Indexed: 10/23/2022]
Abstract
Plant vacuolar H+-translocating inorganic pyrophosphatase (V-PPase EC 3.6.1.1) utilizes inorganic pyrophosphate (PPi) as an energy source to generate a H+ gradient potential for the secondary transport of ions and metabolites across the vacuole membrane. In this study, functional roles of arginine residues in mung bean V-PPase were determined by site-directed mutagenesis. Alignment of amino-acid sequence of K+-dependent V-PPases from several organisms showed that 11 of all 15 arginine residues were highly conserved. Arginine residues were individually substituted by alanine residues to produce R-->A-substituted V-PPases, which were then heterologously expressed in yeast. The characteristics of mutant variants were subsequently scrutinized. As a result, most R-->A-substituted V-PPases exhibited similar enzymatic activities to the wild-type with exception that R242A, R523A, and R609A mutants markedly lost their abilities of PPi hydrolysis and associated H+-translocation. Moreover, mutation on these three arginines altered the optimal pH and significantly reduced K+-stimulation for enzymatic activities, implying a conformational change or a modification in enzymatic reaction upon substitution. In particular, R242A performed striking resistance to specific arginine-modifiers, 2,3-butanedione and phenylglyoxal, revealing that Arg242 is most likely the primary target residue for these two reagents. The mutation at Arg242 also removed F- inhibition that is presumably derived from the interfering in the formation of substrate complex Mg2+-PPi. Our results suggest accordingly that active pocket of V-PPase probably contains the essential Arg242 which is embedded in a more hydrophobic environment.
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Affiliation(s)
- Yi-Yuong Hsiao
- Department of Life Sciences and Institute of Bioinformatics and Structural Biology, College of Life Sciences, National Tsing Hua University, Hsin Chu 30043, Taiwan
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Hirono M, Nakanishi Y, Maeshima M. Essential amino acid residues in the central transmembrane domains and loops for energy coupling of Streptomyces coelicolor A3(2) H+-pyrophosphatase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:930-9. [PMID: 17498645 DOI: 10.1016/j.bbabio.2007.03.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Revised: 03/20/2007] [Accepted: 03/29/2007] [Indexed: 01/30/2023]
Abstract
The H+-translocating inorganic pyrophosphatase is a proton pump that hydrolyzes inorganic pyrophosphate. It consists of a single polypeptide with 14-17 transmembrane domains, and is found in a range of organisms. We focused on the second quarter region of Streptomyces coelicolor A3(2) H+-pyrophosphatase, which contains long conserved cytoplasmic loops. We prepared a library of 1536 mutants that were assayed for pyrophosphate hydrolysis and proton translocation. Mutant enzymes with low substrate hydrolysis and proton-pump activities were selected and their DNAs sequenced. Of these, 34 were single-residue substitution mutants. We generated 29 site-directed mutant enzymes and assayed their activity. The mutation of 10 residues in the fifth transmembrane domain resulted in low coupling efficiencies, and a mutation of Gly198 showed neither hydrolysis nor pumping activity. Four residues in cytoplasmic loop e were essential for substrate hydrolysis and efficient H+ translocation. Pro189, Asp281, and Val351 in the periplasmic loops were critical for enzyme function. Mutation of Ala357 in periplasmic loop h caused a selective reduction of proton-pump activity. These low-efficiency mutants reflect dysfunction of the energy-conversion and/or proton-translocation activities of H+-pyrophosphatase. Four critical residues were also found in transmembrane domain 6, three in transmembrane domain 7, and five in transmembrane domains 8 and 9. These results suggest that transmembrane domain 5 is involved in enzyme function, and that energy coupling is affected by several residues in the transmembrane domains, as well as in the cytoplasmic and periplasmic loops. H+-pyrophosphatase activity might involve dynamic linkage between the hydrophilic and transmembrane domains.
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Affiliation(s)
- Megumi Hirono
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
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Gaxiola RA, Palmgren MG, Schumacher K. Plant proton pumps. FEBS Lett 2007; 581:2204-14. [PMID: 17412324 DOI: 10.1016/j.febslet.2007.03.050] [Citation(s) in RCA: 304] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 03/20/2007] [Accepted: 03/21/2007] [Indexed: 01/10/2023]
Abstract
Chemiosmotic circuits of plant cells are driven by proton (H(+)) gradients that mediate secondary active transport of compounds across plasma and endosomal membranes. Furthermore, regulation of endosomal acidification is critical for endocytic and secretory pathways. For plants to react to their constantly changing environments and at the same time maintain optimal metabolic conditions, the expression, activity and interplay of the pumps generating these H(+) gradients have to be tightly regulated. In this review, we will highlight results on the regulation, localization and physiological roles of these H(+)- pumps, namely the plasma membrane H(+)-ATPase, the vacuolar H(+)-ATPase and the vacuolar H(+)-PPase.
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Affiliation(s)
- Roberto A Gaxiola
- University of Connecticut, 1390 Storrs Road, U-163, Storrs, CT 06269-4163, USA.
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