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García-Contreras R, de la Mora J, Mora-Montes HM, Martínez-Álvarez JA, Vicente-Gómez M, Padilla-Vaca F, Vargas-Maya NI, Franco B. The inorganic pyrophosphatases of microorganisms: a structural and functional review. PeerJ 2024; 12:e17496. [PMID: 38938619 PMCID: PMC11210485 DOI: 10.7717/peerj.17496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 05/09/2024] [Indexed: 06/29/2024] Open
Abstract
Pyrophosphatases (PPases) are enzymes that catalyze the hydrolysis of pyrophosphate (PPi), a byproduct of the synthesis and degradation of diverse biomolecules. The accumulation of PPi in the cell can result in cell death. Although the substrate is the same, there are variations in the catalysis and features of these enzymes. Two enzyme forms have been identified in bacteria: cytoplasmic or soluble pyrophosphatases and membrane-bound pyrophosphatases, which play major roles in cell bioenergetics. In eukaryotic cells, cytoplasmic enzymes are the predominant form of PPases (c-PPases), while membrane enzymes (m-PPases) are found only in protists and plants. The study of bacterial cytoplasmic and membrane-bound pyrophosphatases has slowed in recent years. These enzymes are central to cell metabolism and physiology since phospholipid and nucleic acid synthesis release important amounts of PPi that must be removed to allow biosynthesis to continue. In this review, two aims were pursued: first, to provide insight into the structural features of PPases known to date and that are well characterized, and to provide examples of enzymes with novel features. Second, the scientific community should continue studying these enzymes because they have many biotechnological applications. Additionally, in this review, we provide evidence that there are m-PPases present in fungi; to date, no examples have been characterized. Therefore, the diversity of PPase enzymes is still a fruitful field of research. Additionally, we focused on the roles of H+/Na+ pumps and m-PPases in cell bioenergetics. Finally, we provide some examples of the applications of these enzymes in molecular biology and biotechnology, especially in plants. This review is valuable for professionals in the biochemistry field of protein structure-function relationships and experts in other fields, such as chemistry, nanotechnology, and plant sciences.
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Affiliation(s)
- Rodolfo García-Contreras
- Departamento de Microbiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Javier de la Mora
- Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Héctor Manuel Mora-Montes
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Mexico
| | - José A. Martínez-Álvarez
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Mexico
| | - Marcos Vicente-Gómez
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Mexico
| | - Felipe Padilla-Vaca
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Mexico
| | - Naurú Idalia Vargas-Maya
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Mexico
| | - Bernardo Franco
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Mexico
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Solebo O, Ling L, Nwankwo I, Zhou J, Fu TM, Ke H. Plasmodium falciparum utilizes pyrophosphate to fuel an essential proton pump in the ring stage and the transition to trophozoite stage. PLoS Pathog 2023; 19:e1011818. [PMID: 38048362 PMCID: PMC10732439 DOI: 10.1371/journal.ppat.1011818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 12/20/2023] [Accepted: 11/10/2023] [Indexed: 12/06/2023] Open
Abstract
During asexual growth and replication cycles inside red blood cells, the malaria parasite Plasmodium falciparum primarily relies on glycolysis for energy supply, as its single mitochondrion performs little or no oxidative phosphorylation. Post merozoite invasion of a host red blood cell, the ring stage lasts approximately 20 hours and was traditionally thought to be metabolically quiescent. However, recent studies have shown that the ring stage is active in several energy-costly processes, including gene transcription, protein translation, protein export, and movement inside the host cell. It has remained unclear whether a low glycolytic flux alone can meet the energy demand of the ring stage over a long period post invasion. Here, we demonstrate that the metabolic by-product pyrophosphate (PPi) is a critical energy source for the development of the ring stage and its transition to the trophozoite stage. During early phases of the asexual development, the parasite utilizes Plasmodium falciparum vacuolar pyrophosphatase 1 (PfVP1), an ancient pyrophosphate-driven proton pump, to export protons across the parasite plasma membrane. Conditional deletion of PfVP1 leads to a delayed ring stage that lasts nearly 48 hours and a complete blockage of the ring-to-trophozoite transition before the onset of parasite death. This developmental arrest can be partially rescued by an orthologous vacuolar pyrophosphatase from Arabidopsis thaliana, but not by the soluble pyrophosphatase from Saccharomyces cerevisiae, which lacks proton pumping activities. Since proton-pumping pyrophosphatases have been evolutionarily lost in human hosts, the essentiality of PfVP1 suggests its potential as an antimalarial drug target. A drug target of the ring stage is highly desired, as current antimalarials have limited efficacy against this stage.
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Affiliation(s)
- Omobukola Solebo
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Liqin Ling
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Ikechukwu Nwankwo
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Jing Zhou
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Tian-Min Fu
- Department of Biological Chemistry and Pharmacology, The Ohio State University College of Medicine, Columbus, Ohio, United States of America
- The Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, United States of America
| | - Hangjun Ke
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
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Yang X, Yin X, Liu J, Niu Z, Yang J, Shen B. Essential role of pyrophosphate homeostasis mediated by the pyrophosphate-dependent phosphofructokinase in Toxoplasma gondii. PLoS Pathog 2022; 18:e1010293. [PMID: 35104280 PMCID: PMC8836295 DOI: 10.1371/journal.ppat.1010293] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 02/11/2022] [Accepted: 01/24/2022] [Indexed: 12/27/2022] Open
Abstract
Many biosynthetic pathways produce pyrophosphate (PPi) as a by-product, which is cytotoxic if accumulated at high levels. Pyrophosphatases play pivotal roles in PPi detoxification by converting PPi to inorganic phosphate. A number of apicomplexan parasites, including Toxoplasma gondii and Cryptosporidium parvum, express a PPi-dependent phosphofructokinase (PPi-PFK) that consumes PPi to power the phosphorylation of fructose-6-phosphate. However, the physiological roles of PPi-PFKs in these organisms are not known. Here, we report that Toxoplasma expresses both ATP- and PPi-dependent phosphofructokinases in the cytoplasm. Nonetheless, only PPi-PFK was indispensable for parasite growth, whereas the deletion of ATP-PFK did not affect parasite proliferation or virulence. The conditional depletion of PPi-PFK completely arrested parasite growth, but it did not affect the ATP level and only modestly reduced the flux of central carbon metabolism. However, PPi-PFK depletion caused a significant increase in cellular PPi and decreased the rates of nascent protein synthesis. The expression of a cytosolic pyrophosphatase in the PPi-PFK depletion mutant reduced its PPi level and increased the protein synthesis rate, therefore partially rescuing its growth. These results suggest that PPi-PFK has a major role in maintaining pyrophosphate homeostasis in T. gondii. This role may allow PPi-PFK to fine-tune the balance of catabolism and anabolism and maximize the utilization efficiency for carbon nutrients derived from host cells, increasing the success of parasitism. Moreover, PPi-PFK is essential for parasite propagation and virulence in vivo but it is not present in human hosts, making it a potential drug target to combat toxoplasmosis. Different from classic ATP-dependent phosphofructokinases, PPi-PFKs use pyrophosphate consumption to power the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, the committed step of glycolysis. PPi-PFK is found in diverse organisms including archaea, bacteria, protists and plants. However, half a century after its first discovery, the physiological functions of PPi-PFK are still not well defined. Using the Toxoplasma gondii parasite as a model, here we show that PPi-PFK has a coordinator function to assure matched activities of anabolism and catabolism. This is achieved by maintaining the homeostasis of PPi, which is a byproduct, as well as an inhibitor of many biosynthetic reactions. PPi-PFK hydrolyzes PPi to promote anabolism, meanwhile being a glycolytic enzyme involved in catabolism. As such, it gauges the anabolic and catabolic activities in parasites to maximize the utilization efficiency of acquired nutrients. This work provides important insights to understand the physiological significance of PPi-PFK in Toxoplasma and other organisms.
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Affiliation(s)
- Xuke Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Xiaoyan Yin
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Jiaojiao Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Zhipeng Niu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Jichao Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- * E-mail:
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4
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Wu QF, Wang WS, Chen SB, Xu B, Li YD, Chen JH. Crystal Structure of Inorganic Pyrophosphatase From Schistosoma japonicum Reveals the Mechanism of Chemicals and Substrate Inhibition. Front Cell Dev Biol 2021; 9:712328. [PMID: 34458268 PMCID: PMC8386120 DOI: 10.3389/fcell.2021.712328] [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] [Received: 05/20/2021] [Accepted: 07/15/2021] [Indexed: 11/13/2022] Open
Abstract
Soluble inorganic pyrophosphatases (PPases) are essential for facilitating the growth and development of organisms, making them attractive functional proteins. To provide insight into the molecular basis of PPases in Schistosoma japonicum (SjPPase), we expressed the recombinant SjPPase, analyzed the hydrolysis mechanism of inorganic pyrophosphate (PPi), and measured its activity. Moreover, we solved the crystal structure of SjPPase in complex with orthophosphate (Pi) and performed PPi and methylene diphosphonic acid (MDP) docking into the active site. Our results suggest that the SjPPase possesses PPi hydrolysis activity, and the activity declines with increased MDP or NaF concentration. However, the enzyme shows unexpected substrate inhibition properties. Through PPi metabolic pathway analysis, the physiological action of substrate inhibition might be energy saving, adaptably cytoprotective, and biosynthetic rate regulating. Furthermore, the structure of apo-SjPPase and SjPPase with Pi has been solved at 2.6 and 2.3 Å, respectively. The docking of PPi into the active site of the SjPPase-Pi complex revealed that substrate inhibition might result from blocking Pi exit due to excess PPi in the SjPPase-Pi complex of the catalytic cycle. Our results revealed the structural features of apo-SjPPase and the SjPPase-Pi complex by X-ray crystallography, providing novel insights into the physiological functions of PPase in S. japonicum without the PPi transporter and the mechanism of its substrate inhibition.
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Affiliation(s)
- Qun-Feng Wu
- National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China.,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China.,WHO Collaborating Centre for Tropical Diseases, Shanghai, China.,National Center for International Research on Tropical Diseases, Shanghai, China.,Key Laboratory of Organo-Pharmaceutical Chemistry of Jiangxi Province, Chemistry and Chemical Engineering College, Gannan Normal University, Ganzhou, China
| | - Wei-Si Wang
- National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China.,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China.,WHO Collaborating Centre for Tropical Diseases, Shanghai, China.,National Center for International Research on Tropical Diseases, Shanghai, China
| | - Shen-Bo Chen
- National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China.,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China.,WHO Collaborating Centre for Tropical Diseases, Shanghai, China.,National Center for International Research on Tropical Diseases, Shanghai, China
| | - Bin Xu
- National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China.,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China.,WHO Collaborating Centre for Tropical Diseases, Shanghai, China.,National Center for International Research on Tropical Diseases, Shanghai, China
| | - Yong-Dong Li
- National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China.,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China.,WHO Collaborating Centre for Tropical Diseases, Shanghai, China.,National Center for International Research on Tropical Diseases, Shanghai, China.,Key Laboratory of Organo-Pharmaceutical Chemistry of Jiangxi Province, Chemistry and Chemical Engineering College, Gannan Normal University, Ganzhou, China
| | - Jun-Hu Chen
- National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, China.,NHC Key Laboratory of Parasite and Vector Biology, Shanghai, China.,WHO Collaborating Centre for Tropical Diseases, Shanghai, China.,National Center for International Research on Tropical Diseases, Shanghai, China.,The School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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5
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Asady B, Dick CF, Ehrenman K, Sahu T, Romano JD, Coppens I. A single Na+-Pi cotransporter in Toxoplasma plays key roles in phosphate import and control of parasite osmoregulation. PLoS Pathog 2021; 16:e1009067. [PMID: 33383579 PMCID: PMC7817038 DOI: 10.1371/journal.ppat.1009067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 01/20/2021] [Accepted: 10/14/2020] [Indexed: 11/22/2022] Open
Abstract
Inorganic ions such as phosphate, are essential nutrients required for a broad spectrum of cellular functions and regulation. During infection, pathogens must obtain inorganic phosphate (Pi) from the host. Despite the essentiality of phosphate for all forms of life, how the intracellular parasite Toxoplasma gondii acquires Pi from the host cell is still unknown. In this study, we demonstrated that Toxoplasma actively internalizes exogenous Pi by exploiting a gradient of Na+ ions to drive Pi uptake across the plasma membrane. The Na+-dependent phosphate transport mechanism is electrogenic and functionally coupled to a cipargarmin sensitive Na+-H+-ATPase. Toxoplasma expresses one transmembrane Pi transporter harboring PHO4 binding domains that typify the PiT Family. This transporter named TgPiT, localizes to the plasma membrane, the inward buds of the endosomal organelles termed VAC, and many cytoplasmic vesicles. Upon Pi limitation in the medium, TgPiT is more abundant at the plasma membrane. We genetically ablated the PiT gene, and ΔTgPiT parasites are impaired in importing Pi and synthesizing polyphosphates. Interestingly, ΔTgPiT parasites accumulate 4-times more acidocalcisomes, storage organelles for phosphate molecules, as compared to parental parasites. In addition, these mutants have a reduced cell volume, enlarged VAC organelles, defects in calcium storage and a slightly alkaline pH. Overall, these mutants exhibit severe growth defects and have reduced acute virulence in mice. In survival mode, ΔTgPiT parasites upregulate several genes, including those encoding enzymes that cleave or transfer phosphate groups from phosphometabolites, transporters and ions exchangers localized to VAC or acidocalcisomes. Taken together, these findings point to a critical role of TgPiT for Pi supply for Toxoplasma and also for protection against osmotic stresses. Inorganic phosphate (Pi) is indispensable for the biosynthesis of key cellular components, and is involved in many metabolic and signaling pathways. Transport across the plasma membrane is the first step in the utilization of Pi. The import mechanism of Pi by the intracellular parasite Toxoplasma is unknown. We characterized a transmembrane, high-affinity Na+-Pi cotransporter, named TgPiT, expressed by the parasite at the plasma membrane for Pi uptake. Interestingly, TgPiT is also localized to inward buds of the endosomal VAC organelles and some cytoplasmic vesicles. Loss of TgPiT results in a severe reduction in Pi internalization and polyphosphate levels, but stimulation of the biogenesis of phosphate-enriched acidocalcisomes. ΔTgPiT parasites have a shrunken cell body, enlarged VAC organelles, poor release of stored calcium and a mildly alkaline pH, suggesting a role for TgPiT in the maintenance of overall ionic homeostasis. ΔTgPiT parasites are poorly infectious in vitro and in mice. The mutant appears to partially cope with the absence of TgPiT by up-regulating genes coding for ion transporters and enzymes catalyzing phosphate group transfer. Our data highlight a scenario in which the role of TgPiT in Pi and Na+ transport is functionally coupled with osmoregulation activities central to sustain Toxoplasma survival.
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Affiliation(s)
- Beejan Asady
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore Maryland, United States of America
| | - Claudia F. Dick
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore Maryland, United States of America
| | - Karen Ehrenman
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore Maryland, United States of America
| | - Tejram Sahu
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore Maryland, United States of America
| | - Julia D. Romano
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore Maryland, United States of America
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore Maryland, United States of America
- * E-mail:
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Romanov RS, Mariasina SS, Efimov SV, Klochkov VV, Rodina EV, Polshakov VI. Backbone resonance assignment and dynamics of 110 kDa hexameric inorganic pyrophosphatase from Mycobacterium tuberculosis. BIOMOLECULAR NMR ASSIGNMENTS 2020; 14:281-287. [PMID: 32562252 DOI: 10.1007/s12104-020-09962-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Family I soluble inorganic pyrophosphatases (PPases; EC 3.6.1.1) are enzymes essential for all organisms. They hydrolyze inorganic pyrophosphate, thus providing the driving force for numerous biosynthetic reactions. Soluble PPases retain enzymatic activity only in multimeric forms. PPases from various organisms are extensively studied by X-ray crystallography but until now there was no information on their structure and dynamics in solution. Hexameric 110 kDa (6 × 18.3 kDa) PPase from Mycobacterium tuberculosis (Mt-PPase) is a promising target for the rational design of potential anti-tuberculosis agents. In order to use NMR techniques in functional studies of Mt-PPase and rational design of the inhibitors for this enzyme, it is necessary to have information on the backbone 1H, 13C and 15N resonance assignments. Samples of Mt-PPase enriched with 99% of 13C and 15N isotopes, and 95% of 2H were obtained using recombinant protein expression in an isotopically-labeled medium and effective heat-shock protocol for the deuterium-to-hydrogen exchange of the amide groups. Backbone resonance assignment was achieved for more than 95% of the residues. It was found that the secondary structure of Mt-PPase in solution corresponds well to the crystal structure of this protein. Protein backbone dynamics were studied using 15N NMR relaxation experiments. Determined resonance assignments and dynamic properties provide the basis for the subsequent structure-based design of novel inhibitors of Mt-PPase-potential anti-tuberculosis drugs.
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Affiliation(s)
- Roman S Romanov
- Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
| | - Sofia S Mariasina
- Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
| | - Sergey V Efimov
- NMR Laboratory, Institute of Physics, Kazan Federal University, 18 Kremlevskaya St., Kazan, Russia, 420008
| | - Vladimir V Klochkov
- NMR Laboratory, Institute of Physics, Kazan Federal University, 18 Kremlevskaya St., Kazan, Russia, 420008
| | - Elena V Rodina
- Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
| | - Vladimir I Polshakov
- Center for Magnetic Tomography and Spectroscopy, Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University, 119991, Moscow, Russia.
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Stasic AJ, Chasen NM, Dykes EJ, Vella SA, Asady B, Starai VJ, Moreno SNJ. The Toxoplasma Vacuolar H +-ATPase Regulates Intracellular pH and Impacts the Maturation of Essential Secretory Proteins. Cell Rep 2020; 27:2132-2146.e7. [PMID: 31091451 PMCID: PMC6760873 DOI: 10.1016/j.celrep.2019.04.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 10/31/2018] [Accepted: 04/05/2019] [Indexed: 12/20/2022] Open
Abstract
Vacuolar-proton ATPases (V-ATPases) are conserved complexes that couple the hydrolysis of ATP to the pumping of protons across membranes. V-ATPases are known to play diverse roles in cellular physiology. We studied the Toxoplasma gondii V-ATPase complex and discovered a dual role of the pump in protecting parasites against ionic stress and in the maturation of secretory proteins in endosomal-like compartments. Toxoplasma V-ATPase subunits localize to the plasma membrane and to acidic vesicles, and characterization of conditional mutants of the a1 subunit highlighted the functionality of the complex at both locations. Microneme and rhoptry proteins are required for invasion and modulation of host cells, and they traffic via endosome-like compartments in which proteolytic maturation occurs. We show that the V-ATPase supports the maturation of rhoptry and microneme proteins, and their maturases, during their traffic to their corresponding organelles. This work underscores a role for V-ATPases in regulating virulence pathways. Stasic et al. characterize the function of the vacuolar proton ATPase in the life cycle of Toxoplasma gondii, a widespread parasite that infects almost one-third of the world’s population. The work presents molecular evidence of the pump’s role in the synthesis of virulence factors of a highly successful pathogen.
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Affiliation(s)
- Andrew J Stasic
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602-7400, USA; Department of Microbiology, University of Georgia, Athens, GA 30602-7400, USA
| | - Nathan M Chasen
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602-7400, USA; Department of Infectious Diseases, University of Georgia, Athens, GA 30602-7400, USA
| | - Eric J Dykes
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602-7400, USA
| | - Stephen A Vella
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602-7400, USA; Department of Microbiology, University of Georgia, Athens, GA 30602-7400, USA
| | - Beejan Asady
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602-7400, USA
| | - Vincent J Starai
- Department of Microbiology, University of Georgia, Athens, GA 30602-7400, USA; Department of Infectious Diseases, University of Georgia, Athens, GA 30602-7400, USA
| | - Silvia N J Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602-7400, USA; Department of Cellular Biology, University of Georgia, Athens, GA 30602-7400, USA.
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8
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Associations of canopy leaf traits with SNP markers in durum wheat (Triticum turgidum L. durum (Desf.)). PLoS One 2018; 13:e0206226. [PMID: 30352102 PMCID: PMC6198983 DOI: 10.1371/journal.pone.0206226] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 10/09/2018] [Indexed: 11/23/2022] Open
Abstract
The canopy leaves including the top three, i.e., the flag, the 2nd and 3rd from the top, are important for photosynthesis and grain yield of wheat. Molecular markers associated with traits of these leaves should be helpful for the high-yielding breeding. In this study, 1366 single nucleotide polymorphisms (SNP) markers covering the whole genome of durum wheat were used to genotype 150 cultivars collected from 46 countries and regions in the world. Leaf length, leaf width and chlorophyll content of the top three leaves were measured, respectively, in three consecutive years. Association analyses were performed on the leaf traits and SNP markers. A total of 120 SNP marker associations were detected on 13 of the 14 chromosomes. Among these markers, 83 were associated with the canopy leaf traits, 10 with 1000-grain weight, and 29 with kernel number per spike. This study is helpful for better understanding the potential and genetic basis of functional leaves, and facilitates pyramiding of the favorable alleles using marker assisted selection for ideal plant-type and high photosynthesis efficiency in durum wheat breeding.
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Narvaez-Ortiz HY, Lopez AJ, Gupta N, Zimmermann BH. A CTP Synthase Undergoing Stage-Specific Spatial Expression Is Essential for the Survival of the Intracellular Parasite Toxoplasma gondii. Front Cell Infect Microbiol 2018; 8:83. [PMID: 29623259 PMCID: PMC5874296 DOI: 10.3389/fcimb.2018.00083] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/28/2018] [Indexed: 01/17/2023] Open
Abstract
Cytidine triphosphate synthase catalyzes the synthesis of cytidine 5′-triphosphate (CTP) from uridine 5′-triphosphate (UTP), the final step in the production of cytidine nucleotides. CTP synthases also form filamentous structures of different morphologies known as cytoophidia, whose functions in most organisms are unknown. Here, we identified and characterized a novel CTP synthase (TgCTPS) from Toxoplasma gondii. We show that TgCTPS is capable of substituting for its counterparts in the otherwise lethal double mutant (ura7Δ ura8Δ) of Saccharomyces cerevisiae. Equally, recombinant TgCTPS purified from Escherichia coli encodes for a functional protein in enzyme assays. The epitope-tagged TgCTPS under the control of its endogenous promoter displays a punctate cytosolic distribution, which undergoes spatial reorganization to form foci or filament-like structures when the parasite switches from a nutrient-replete (intracellular) to a nutrient-scarce (extracellular) condition. An analogous phenotype is observed upon nutrient stress or after treatment with a glutamine analog, 6-diazo-5-oxo-L-norleucine (DON). The exposure of parasites to DON disrupts the lytic cycle, and the TgCTPS is refractory to a genetic deletion, suggesting an essential requirement of this enzyme for T. gondii. Not least, this study, together with previous studies, supports that CTP synthase can serve as a potent drug target, because the parasite, unlike human host cells, cannot compensate for the lack of CTP synthase activity.
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Affiliation(s)
| | - Andrea J Lopez
- Departamento de Ciencias Biologicas, Universidad de los Andes, Bogota, Colombia
| | - Nishith Gupta
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
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Jamwal A, Yogavel M, Abdin MZ, Jain SK, Sharma A. Structural and Biochemical Characterization of Apicomplexan Inorganic Pyrophosphatases. Sci Rep 2017; 7:5255. [PMID: 28701714 PMCID: PMC5507929 DOI: 10.1038/s41598-017-05234-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 05/25/2017] [Indexed: 11/17/2022] Open
Abstract
Inorganic pyrophosphatases (PPase) participate in energy cycling and they are essential for growth and survival of organisms. Here we report extensive structural and functional characterization of soluble PPases from the human parasites Plasmodium falciparum (PfPPase) and Toxoplasma gondii (TgPPase). Our results show that PfPPase is a cytosolic enzyme whose gene expression is upregulated during parasite asexual stages. Cambialistic PfPPase actively hydrolyzes linear short chain polyphosphates like PPi, polyP3 and ATP in the presence of Zn2+. A remarkable new feature of PfPPase is the low complexity asparagine-rich N-terminal region that mediates its dimerization. Deletion of N-region has an unexpected and substantial effect on the stability of PfPPase domain, resulting in aggregation and significant loss of enzyme activity. Significantly, the crystal structures of PfPPase and TgPPase reveal unusual and unprecedented dimeric organizations and provide new fundamental insights into the variety of oligomeric assemblies possible in eukaryotic inorganic PPases.
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Affiliation(s)
- Abhishek Jamwal
- Molecular Medicine Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.,Department of Biotechnology, Jamia Hamdard, New Delhi, 110063, India
| | - Manickam Yogavel
- Molecular Medicine Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Malik Z Abdin
- Department of Biotechnology, Jamia Hamdard, New Delhi, 110063, India
| | - Swatantra K Jain
- Department of Biotechnology, Jamia Hamdard, New Delhi, 110063, India.,Department of Biochemistry, Hamdard Institute of Medical Sciences, 110063, New Delhi, India
| | - Amit Sharma
- Molecular Medicine Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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Mallo N, Lamas J, DeFelipe AP, Sueiro RA, Fontenla F, Leiro JM. Enzymes Involved in Pyrophosphate and Calcium Metabolism as Targets for Anti-scuticociliate Chemotherapy. J Eukaryot Microbiol 2016; 63:505-15. [DOI: 10.1111/jeu.12294] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 12/18/2015] [Accepted: 01/05/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Natalia Mallo
- Departamento de Microbiología y Parasitología; Instituto de Investigación y Análisis Alimentarios; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - Jesús Lamas
- Departamento de Biología Celular y Ecología; Facultad de Biología; Instituto de Acuicultura; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - Ana-Paula DeFelipe
- Departamento de Microbiología y Parasitología; Instituto de Investigación y Análisis Alimentarios; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - Rosa-Ana Sueiro
- Departamento de Microbiología y Parasitología; Instituto de Investigación y Análisis Alimentarios; Universidad de Santiago de Compostela; Santiago de Compostela Spain
- Departamento de Biología Celular y Ecología; Facultad de Biología; Instituto de Acuicultura; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - Francisco Fontenla
- Departamento de Biología Celular y Ecología; Facultad de Biología; Instituto de Acuicultura; Universidad de Santiago de Compostela; Santiago de Compostela Spain
| | - José-Manuel Leiro
- Departamento de Microbiología y Parasitología; Instituto de Investigación y Análisis Alimentarios; Universidad de Santiago de Compostela; Santiago de Compostela Spain
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12
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Presence of a plant-like proton-translocating pyrophosphatase in a scuticociliate parasite and its role as a possible drug target. Parasitology 2014; 142:449-62. [DOI: 10.1017/s0031182014001267] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
SUMMARYThe proton-translocating inorganic pyrophosphatases (H+-PPases) are primary electrogenic H+ pumps that derive energy from the hydrolysis of inorganic pyrophosphate (PPi). They are widely distributed among most land plants and have also been found in several species of protozoan parasites. Here we describe, for the first time, the molecular cloning and functional characterization of a gene encoding an H+-pyrophosphatase in the protozoan scuticociliate parasite Philasterides dicentrarchi, which infects turbot. The predicted P. dicentrarchi PPase (PdPPase) consists of 587 amino acids of molecular mass 61·7 kDa and an isoelectric point of 5·0. Several motifs characteristic of plant vacuolar H+-PPases (V–H+-PPases) were also found in the PdPPase, which contains all the sequence motifs of the prototypical type I V–H+-PPase from Arabidopsis thaliana vacuolar pyrophosphatase type I (AVP1) plant. The PdPPase has a characteristic residue that determines strict K+-dependence, but unlike AVP1, PdPPase contains an N-terminal signal peptide (SP) sequence. Antibodies generated by vaccination of mice with a genetic or recombinant protein containing a partial sequence of the PdPPase and a common motif with the polyclonal antibody PABHK specific to AVP1 recognized a single band of about 62 kDa in western blots. These antibodies specifically stained both vacuole and the alveolar membranes of trophozoites of P. dicentrarchi. H+ transport was partially inhibited by the bisphosphonate pamidronate (PAM) and completely inhibited by NaF. The bisphosphonate PAM inhibited both H+-translocation and gene expression. PdPPase and PAM also inhibited in vitro growth of the ciliates. The apparent lack of V–H+-PPases in vertebrates and the parasite sensitivity to PPI analogues may provide a molecular target for developing new drugs to control scuticociliatosis.
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Liu J, Pace D, Dou Z, King TP, Guidot D, Li ZH, Carruthers VB, Moreno SNJ. A vacuolar-H(+) -pyrophosphatase (TgVP1) is required for microneme secretion, host cell invasion, and extracellular survival of Toxoplasma gondii. Mol Microbiol 2014; 93:698-712. [PMID: 24975633 DOI: 10.1111/mmi.12685] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/19/2014] [Indexed: 01/17/2023]
Abstract
The vacuolar proton pyrophosphatase (H(+) -PPase) of Toxoplasma gondii (TgVP1), a membrane proton pump, localizes to acidocalcisomes and a novel lysosome-like compartment termed plant-like vacuole (PLV) or vacuolar compartment (VAC). We report the characterization of a T. gondii null mutant for the TgVP1 gene. Propagation of these mutants decreased significantly because of deficient attachment and invasion of host cells, which correlated with deficient microneme secretion. Processing of cathepsin L (CPL) in these mutants was deficient only when the parasites were incubated in the presence of low concentrations of the vacuolar H(+) -ATPase (V-H(+) -ATPase) inhibitor bafilomycin A1 , suggesting that either TgVP1 or the T. gondii V-H(+) -ATPase (TgVATPase) are sufficient to support CPL processing. The lack of TgVP1 did not affect processing of micronemal proteins, indicating that it does not contribute to proMIC maturations. The TgVP1 null mutants were more sensitive to extracellular conditions and were less virulent in mice. We demonstrate that T. gondii tachyzoites possess regulatory volume decrease capability during hypo-osmotic stress and this ability is impaired in TgVP1 null mutants implicating TgVP1 in osmoregulation. We hypothesize that osmoregulation is needed for host cell invasion and that TgVP1 plays a role during the normal lytic cycle of T. gondii.
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Affiliation(s)
- Jing Liu
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, GA, 30602-7400, USA; College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
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14
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Li ZH, Ramakrishnan S, Striepen B, Moreno SNJ. Toxoplasma gondii relies on both host and parasite isoprenoids and can be rendered sensitive to atorvastatin. PLoS Pathog 2013; 9:e1003665. [PMID: 24146616 PMCID: PMC3798403 DOI: 10.1371/journal.ppat.1003665] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 08/14/2013] [Indexed: 01/03/2023] Open
Abstract
Intracellular pathogens have complex metabolic interactions with their host cells to ensure a steady supply of energy and anabolic building blocks for rapid growth. Here we use the obligate intracellular parasite Toxoplasma gondii to probe this interaction for isoprenoids, abundant lipidic compounds essential to many cellular processes including signaling, trafficking, energy metabolism, and protein translation. Synthesis of precursors for isoprenoids in Apicomplexa occurs in the apicoplast and is essential. To synthesize longer isoprenoids from these precursors, T. gondii expresses a bifunctional farnesyl diphosphate/geranylgeranyl diphosphate synthase (TgFPPS). In this work we construct and characterize T. gondii null mutants for this enzyme. Surprisingly, these mutants have only a mild growth phenotype and an isoprenoid composition similar to wild type parasites. However, when extracellular, the loss of the enzyme becomes phenotypically apparent. This strongly suggests that intracellular parasite salvage FPP and/or geranylgeranyl diphosphate (GGPP) from the host. We test this hypothesis using inhibitors of host cell isoprenoid synthesis. Mammals use the mevalonate pathway, which is susceptible to statins. We document strong synergy between statin treatment and pharmacological or genetic interference with the parasite isoprenoid pathway. Mice can be cured with atorvastatin (Lipitor) from a lethal infection with the TgFPPs mutant. We propose a double-hit strategy combining inhibitors of host and parasite pathways as a novel therapeutic approach against Apicomplexan parasites. Toxoplasma gondii is an obligate intracellular parasite and is not able to replicate outside the host cell. The parasite lives in a specialized parasitophorous vacuole in contact with the host cytoplasm through the parasitophorous vacuole membrane. It is highly likely that a very active exchange of metabolites occurs between parasite and host cell. We present evidence for this exchange for isoprenoids, abundant lipidic compounds essential to many cellular processes including signaling, trafficking, energy metabolism, and protein translation. Our work shows that intracellular T. gondii tachyzoites are able to salvage farnesyl diphosphate (FPP) and/or geranylgeranyl diphosphate (GGPP) from the host, and the parasite is able to grow even when its endogenous production is shut down. However, when extracellular, the parasite depends entirely on its own production of isoprenoids. We propose to use a combination of inhibitors that would hit both the host and the parasite pathways as a novel therapeutic approach against Toxoplasma gondii that could also work against other Apicomplexan parasites.
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Affiliation(s)
- Zhu-Hong Li
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Srinivasan Ramakrishnan
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Boris Striepen
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Silvia N. J. Moreno
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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