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Reghunandanan K, T P A, Krishnan N, K M D, Prasad R, Nelson-Sathi S, Chandramohanadas R. Search for novel Plasmodium falciparum PfATP4 inhibitors from the MMV Pandemic Response Box through a virtual screening approach. J Biomol Struct Dyn 2024; 42:6200-6211. [PMID: 37424150 DOI: 10.1080/07391102.2023.2232459] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 06/27/2023] [Indexed: 07/11/2023]
Abstract
Owing to its life cycle involving multiple hosts and species-specific biological complexities, a vaccine against Plasmodium, the causative agent of Malaria remains elusive. This makes chemotherapy the only viable means to address the clinical manifestations and spread of this deadly disease. However, rapid surge in antimalarial resistance poses significant challenges to our efforts to eliminate Malaria since the best drug available to-date; Artemisinin and its combinations are also rapidly losing efficacy. Sodium ATPase (PfATP4) of Plasmodium has been recently explored as a suitable target for new antimalarials such as Cipargamin. Prior studies showed that multiple compounds from the Medicines for Malaria Venture (MMV) chemical libraries were efficient PfATP4 inhibitors. In this context, we undertook a structure- based virtual screening approach combined to Molecular Dynamic (MD) simulations to evaluate whether new molecules with binding affinity towards PfATP4 could be identified from the Pandemic Response Box (PRB), a 400-compound library of small molecules launched in 2019 by MMV. Our analysis identified new molecules from the PRB library that showed affinity for distinct binding sites including the previously known G358 site, several of which are clinically used anti-bacterial (MMV1634383, MMV1634402), antiviral (MMV010036, MMV394033) or antifungal (MMV1634494) agents. Therefore, this study highlights the possibility of exploiting PRB molecules against Malaria through abrogation of PfATP4 activity.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Keerthy Reghunandanan
- DBT-Rajiv Gandhi Centre for Biotechnology, Red Cell Diseases Laboratory, Thiruvananthapuram, India
| | - Akhila T P
- DBT-Rajiv Gandhi Centre for Biotechnology, Red Cell Diseases Laboratory, Thiruvananthapuram, India
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Nandini Krishnan
- DBT-Rajiv Gandhi Centre for Biotechnology, Red Cell Diseases Laboratory, Thiruvananthapuram, India
| | - Darsana K M
- DBT-Rajiv Gandhi Centre for Biotechnology, Red Cell Diseases Laboratory, Thiruvananthapuram, India
| | - Roshny Prasad
- DBT-Rajiv Gandhi Centre for Biotechnology, Bioinformatics Laboratory, Thiruvananthapuram, India
| | - Shijulal Nelson-Sathi
- DBT-Rajiv Gandhi Centre for Biotechnology, Bioinformatics Laboratory, Thiruvananthapuram, India
| | - Rajesh Chandramohanadas
- DBT-Rajiv Gandhi Centre for Biotechnology, Red Cell Diseases Laboratory, Thiruvananthapuram, India
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2
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Mongue AJ, Martin SH, Manweiler REV, Scullion H, Koehn JL, de Roode JC, Walters JR. Genome sequence of Ophryocystis elektroscirrha, an apicomplexan parasite of monarch butterflies: cryptic diversity and response to host-sequestered plant chemicals. BMC Genomics 2023; 24:278. [PMID: 37226080 DOI: 10.1186/s12864-023-09350-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 04/29/2023] [Indexed: 05/26/2023] Open
Abstract
Apicomplexa are ancient and diverse organisms which have been poorly characterized by modern genomics. To better understand the evolution and diversity of these single-celled eukaryotes, we sequenced the genome of Ophryocystis elektroscirrha, a parasite of monarch butterflies, Danaus plexippus. We contextualize our newly generated resources within apicomplexan genomics before answering longstanding questions specific to this host-parasite system. To start, the genome is miniscule, totaling only 9 million bases and containing fewer than 3,000 genes, half the gene content of two other sequenced invertebrate-infecting apicomplexans, Porospora gigantea and Gregarina niphandrodes. We found that O. elektroscirrha shares different orthologs with each sequenced relative, suggesting the true set of universally conserved apicomplexan genes is very small indeed. Next, we show that sequencing data from other potential host butterflies can be used to diagnose infection status as well as to study diversity of parasite sequences. We recovered a similarly sized parasite genome from another butterfly, Danaus chrysippus, that was highly diverged from the O. elektroscirrha reference, possibly representing a distinct species. Using these two new genomes, we investigated potential evolutionary response by parasites to toxic phytochemicals their hosts ingest and sequester. Monarch butterflies are well-known to tolerate toxic cardenolides thanks to changes in the sequence of their Type II ATPase sodium pumps. We show that Ophryocystis completely lacks Type II or Type 4 sodium pumps, and related proteins PMCA calcium pumps show extreme sequence divergence compared to other Apicomplexa, demonstrating new avenues of research opened by genome sequencing of non-model Apicomplexa.
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Affiliation(s)
- Andrew J Mongue
- Department of Entomology and Nematology, University of Florida, Gainesville, USA.
| | - Simon H Martin
- Institute of Ecology and Evolution, University of Edinburgh, Edinburgh, UK
| | - Rachel E V Manweiler
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, USA
| | - Helena Scullion
- Department of Entomology and Nematology, University of Florida, Gainesville, USA
| | - Jordyn L Koehn
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, USA
| | | | - James R Walters
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, USA
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3
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Down the membrane hole: Ion channels in protozoan parasites. PLoS Pathog 2022; 18:e1011004. [PMID: 36580479 PMCID: PMC9799330 DOI: 10.1371/journal.ppat.1011004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Parasitic diseases caused by protozoans are highly prevalent around the world, disproportionally affecting developing countries, where coinfection with other microorganisms is common. Control and treatment of parasitic infections are constrained by the lack of specific and effective drugs, plus the rapid emergence of resistance. Ion channels are main drug targets for numerous diseases, but their potential against protozoan parasites is still untapped. Ion channels are membrane proteins expressed in all types of cells, allowing for the flow of ions between compartments, and regulating cellular functions such as membrane potential, excitability, volume, signaling, and death. Channels and transporters reside at the interface between parasites and their hosts, controlling nutrient uptake, viability, replication, and infectivity. To understand how ion channels control protozoan parasites fate and to evaluate their suitability for therapeutics, we must deepen our knowledge of their structure, function, and modulation. However, methodological approaches commonly used in mammalian cells have proven difficult to apply in protozoans. This review focuses on ion channels described in protozoan parasites of clinical relevance, mainly apicomplexans and trypanosomatids, highlighting proteins for which molecular and functional evidence has been correlated with their physiological functions.
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4
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Mohring F, van Schalkwyk DA, Henrici RC, Blasco B, Leroy D, Sutherland CJ, Moon RW. Cation ATPase (ATP4) Orthologue Replacement in the Malaria Parasite Plasmodium knowlesi Reveals Species-Specific Responses to ATP4-Targeting Drugs. mBio 2022; 13:e0117822. [PMID: 36190127 PMCID: PMC9600963 DOI: 10.1128/mbio.01178-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/31/2022] [Indexed: 11/30/2022] Open
Abstract
Several unrelated classes of antimalarial compounds developed against Plasmodium falciparum target a parasite-specific P-type ATP-dependent Na+ pump, PfATP4. We have previously shown that other malaria parasite species infecting humans are less susceptible to these compounds. Here, we generated a series of transgenic Plasmodium knowlesi orthologue replacement (OR) lines in which the endogenous pkatp4 locus was replaced by a recodonized P. knowlesi atp4 (pkatp4) coding region or the orthologous coding region from P. falciparum, Plasmodium malariae, Plasmodium ovale subsp. curtisi, or Plasmodium vivax. Each OR transgenic line displayed a similar growth pattern to the parental P. knowlesi line. We found significant orthologue-specific differences in parasite susceptibility to three chemically unrelated ATP4 inhibitors, but not to comparator drugs, among the P. knowlesi OR lines. The PfATP4OR transgenic line of P. knowlesi was significantly more susceptible than our control PkATP4OR line to three ATP4 inhibitors: cipargamin, PA21A092, and SJ733. The PvATP4OR and PmATP4OR lines were similarly susceptible to the control PkATP4OR line, but the PocATP4OR line was significantly less susceptible to all ATP4 inhibitors than the PkATP4OR line. Cipargamin-induced inhibition of Na+ efflux was also significantly greater with the P. falciparum orthologue of ATP4. This confirms that species-specific susceptibility differences previously observed in ex vivo studies of human isolates are partly or wholly enshrined in the primary amino acid sequences of the respective ATP4 orthologues and highlights the need to monitor efficacy of investigational malaria drugs against multiple species. P. knowlesi is now established as an important in vitro model for studying drug susceptibility in non-falciparum malaria parasites. IMPORTANCE Effective drugs are vital to minimize the illness and death caused by malaria. Development of new drugs becomes ever more urgent as drug resistance emerges. Among promising compounds now being developed to treat malaria are several unrelated molecules that each inhibit the same protein in the malaria parasite-ATP4. Here, we exploited the genetic tractability of P. knowlesi to replace its own ATP4 genes with orthologues from five human-infective species to understand the drug susceptibility differences among these parasites. We previously estimated the susceptibility to ATP4-targeting drugs of each species using clinical samples from malaria patients. These estimates closely matched those of the corresponding "hybrid" P. knowlesi parasites carrying introduced ATP4 genes. Thus, species-specific ATP4 inhibitor efficacy is directly determined by the sequence of the gene. Our novel approach to understanding cross-species susceptibility/resistance can strongly support the effort to develop antimalarials that effectively target all human malaria parasite species.
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Affiliation(s)
- Franziska Mohring
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Donelly A. van Schalkwyk
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ryan C. Henrici
- Center for Global Health, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Colin J. Sutherland
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- UK Health Security Agency Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Robert W. Moon
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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5
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Qiu D, Pei JV, Rosling JEO, Thathy V, Li D, Xue Y, Tanner JD, Penington JS, Aw YTV, Aw JYH, Xu G, Tripathi AK, Gnadig NF, Yeo T, Fairhurst KJ, Stokes BH, Murithi JM, Kümpornsin K, Hasemer H, Dennis ASM, Ridgway MC, Schmitt EK, Straimer J, Papenfuss AT, Lee MCS, Corry B, Sinnis P, Fidock DA, van Dooren GG, Kirk K, Lehane AM. A G358S mutation in the Plasmodium falciparum Na + pump PfATP4 confers clinically-relevant resistance to cipargamin. Nat Commun 2022; 13:5746. [PMID: 36180431 PMCID: PMC9525273 DOI: 10.1038/s41467-022-33403-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 09/16/2022] [Indexed: 11/30/2022] Open
Abstract
Diverse compounds target the Plasmodium falciparum Na+ pump PfATP4, with cipargamin and (+)-SJ733 the most clinically-advanced. In a recent clinical trial for cipargamin, recrudescent parasites emerged, with most having a G358S mutation in PfATP4. Here, we show that PfATP4G358S parasites can withstand micromolar concentrations of cipargamin and (+)-SJ733, while remaining susceptible to antimalarials that do not target PfATP4. The G358S mutation in PfATP4, and the equivalent mutation in Toxoplasma gondii ATP4, decrease the sensitivity of ATP4 to inhibition by cipargamin and (+)-SJ733, thereby protecting parasites from disruption of Na+ regulation. The G358S mutation reduces the affinity of PfATP4 for Na+ and is associated with an increase in the parasite's resting cytosolic [Na+]. However, no defect in parasite growth or transmissibility is observed. Our findings suggest that PfATP4 inhibitors in clinical development should be tested against PfATP4G358S parasites, and that their combination with unrelated antimalarials may mitigate against resistance development.
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Affiliation(s)
- Deyun Qiu
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Jinxin V Pei
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - James E O Rosling
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Vandana Thathy
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Dongdi Li
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Yi Xue
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - John D Tanner
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Jocelyn Sietsma Penington
- Bioinformatic Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Yi Tong Vincent Aw
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Jessica Yi Han Aw
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Guoyue Xu
- Department of Molecular Microbiology & Immunology and Johns Hopkins Malaria Institute, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA
| | - Abhai K Tripathi
- Department of Molecular Microbiology & Immunology and Johns Hopkins Malaria Institute, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA
| | - Nina F Gnadig
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Tomas Yeo
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Kate J Fairhurst
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Barbara H Stokes
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - James M Murithi
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | | | - Heath Hasemer
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Adelaide S M Dennis
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Melanie C Ridgway
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | | | - Judith Straimer
- Novartis Institute for Tropical Diseases, Emeryville, CA, 94608, USA
| | - Anthony T Papenfuss
- Bioinformatic Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Marcus C S Lee
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
| | - Ben Corry
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Photini Sinnis
- Department of Molecular Microbiology & Immunology and Johns Hopkins Malaria Institute, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA
| | - David A Fidock
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
- Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Giel G van Dooren
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Kiaran Kirk
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Adele M Lehane
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia.
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6
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Monteiro Júnior JC, Krüger A, Palmisano G, Wrenger C. Transporter-Mediated Solutes Uptake as Drug Target in Plasmodium falciparum. Front Pharmacol 2022; 13:845841. [PMID: 35370717 PMCID: PMC8965513 DOI: 10.3389/fphar.2022.845841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/09/2022] [Indexed: 02/05/2023] Open
Abstract
Malaria remains a public health problem with still more than half a million deaths annually. Despite ongoing efforts of many countries, malaria elimination has been difficult due to emerging resistances against most traditional drugs, including artemisinin compounds - the most potent antimalarials currently available. Therefore, the discovery and development of new drugs with novel mechanisms of action to circumvent resistances is urgently needed. In this sense, one of the most promising areas is the exploration of transport proteins. Transporters mediate solute uptake for intracellular parasite proliferation and survival. Targeting transporters can exploit these processes to eliminate the parasite. Here, we focus on transporters of the Plasmodium falciparum-infected red blood cell studied as potential biological targets and discuss published drugs directed at them.
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Affiliation(s)
- Júlio César Monteiro Júnior
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Arne Krüger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Giuseppe Palmisano
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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7
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Yano J, Wells R, Lam YW, Van Houten JL. Ciliary Ca2+ pumps regulate intraciliary Ca2+ from the action potential and may co-localize with ciliary voltage-gated Ca2+ channels. J Exp Biol 2021; 224:261763. [PMID: 33944932 DOI: 10.1242/jeb.232074] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 03/02/2021] [Indexed: 11/20/2022]
Abstract
Calcium ions (Ca2+) entering cilia through the ciliary voltage-gated calcium channels (CaV) during the action potential causes reversal of the ciliary power stroke and backward swimming in Paramecium tetraurelia. How calcium is returned to the resting level is not yet clear. Our focus is on calcium pumps as a possible mechanism. There are 23 P. tetraurelia genes for calcium pumps that are members of the family of plasma membrane Ca2+ ATPases (PMCAs). They have domains homologous to those found in mammalian PMCAs. Of the 13 pump proteins previously identified in cilia, ptPMCA2a and ptPMCA2b are most abundant in the cilia. We used RNAi to examine which PMCA might be involved in regulating intraciliary Ca2+ after the action potential. RNAi for only ptPMCA2a and ptPMCA2b causes cells to significantly prolong their backward swimming, which indicates that Ca2+ extrusion in the cilia is impaired when these PMCAs are depleted. We used immunoprecipitations (IP) to find that ptPMCA2a and ptPMCA2b are co-immunoprecipitated with the CaV channel α1 subunits that are found only in the cilia. We used iodixanol (OptiPrep) density gradients to show that ptPMCA2a and ptPMCA2b and CaV1c are found in the same density fractions. These results suggest that ptPMCA2a and ptPMCA2b are located in the proximity of ciliary CaV channels.
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Affiliation(s)
- Junji Yano
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Russell Wells
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Ying-Wai Lam
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
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8
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Dick CF, Meyer-Fernandes JR, Vieyra A. The Functioning of Na +-ATPases from Protozoan Parasites: Are These Pumps Targets for Antiparasitic Drugs? Cells 2020; 9:E2225. [PMID: 33023071 PMCID: PMC7600311 DOI: 10.3390/cells9102225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022] Open
Abstract
The ENA ATPases (from exitus natru: the exit of sodium) belonging to the P-type ATPases are structurally very similar to the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA); they exchange Na+ for H+ and, therefore, are also known as Na+-ATPases. ENA ATPases are required in alkaline milieu, as in the case for Aspergillus, where other transporters cannot mediate an uphill Na+ efflux. They are also important for salt tolerance, as described for Arabidopsis. During their life cycles, protozoan parasites might encounter a high pH environment, thus allowing consideration of ENA ATPases as possible targets for controlling certain severe parasitic diseases, such as Chagas' Disease. Phylogenetic analysis has now shown that, besides the types IIA, IIB, IIC, and IID P-type ATPases, there exists a 5th subgroup of ATPases classified as ATP4-type ATPases, found in Plasmodium falciparum and Toxoplasma gondii. In malaria, for example, some drugs targeting PfATP4 destroy Na+ homeostasis; these drugs, which include spiroindolones, are now in clinical trials. The ENA P-type (IID P-type ATPase) and ATP4-type ATPases have no structural homologue in mammalian cells, appearing only in fungi, plants, and protozoan parasites, e.g., Trypanosoma cruzi, Leishmania sp., Toxoplasma gondii, and Plasmodium falciparum. This exclusivity makes Na+-ATPase a potential candidate for the biologically-based design of new therapeutic interventions; for this reason, Na+-ATPases deserves more attention.
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Affiliation(s)
- Claudia F. Dick
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil;
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro 21941-170, Brazil;
- National Center of Structural Biology and Bioimaging/CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - José Roberto Meyer-Fernandes
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil;
- National Center of Structural Biology and Bioimaging/CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Adalberto Vieyra
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro 21941-170, Brazil;
- National Center of Structural Biology and Bioimaging/CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
- Graduate Programa of Translational Biomedicine/BIOTRANS, Unigranrio University, Duque de Caxias 25071-202, Brazil
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9
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Molbaek K, Tejada M, Ricke CH, Scharff-Poulsen P, Ellekvist P, Helix-Nielsen C, Kumar N, Klaerke DA, Pedersen PA. Purification and initial characterization of Plasmodium falciparum K + channels, PfKch1 and PfKch2 produced in Saccharomyces cerevisiae. Microb Cell Fact 2020; 19:183. [PMID: 32957994 PMCID: PMC7507820 DOI: 10.1186/s12934-020-01437-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/09/2020] [Indexed: 02/07/2023] Open
Abstract
Resistance towards known antimalarial drugs poses a significant problem, urging for novel drugs that target vital proteins in the malaria parasite Plasmodium falciparum. However, recombinant production of malaria proteins is notoriously difficult. To address this, we have investigated two putative K+ channels, PfKch1 and PfKch2, identified in the P. falciparum genome. We show that PfKch1 and PfKch2 and a C-terminally truncated version of PfKch1 (PfKch11−1094) could indeed be functionally expressed in vivo, since a K+-uptake deficient Saccharomyces cerevisiae strain was complemented by the P. falciparum cDNAs. PfKch11−1094-GFP and GFP-PfKch2 fusion proteins were overexpressed in yeast, purified and reconstituted in lipid bilayers to determine their electrophysiological activity. Single channel conductance amounted to 16 ± 1 pS for PfKch11−1094-GFP and 28 ± 2 pS for GFP-PfKch2. We predicted regulator of K+-conductance (RCK) domains in the C-terminals of both channels, and we accordingly measured channel activity in the presence of Ca2+.
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Affiliation(s)
- Karen Molbaek
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, 1870, Denmark.,Department of Biology, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Maria Tejada
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, 1870, Denmark
| | - Christina Hoeier Ricke
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, 1870, Denmark
| | - Peter Scharff-Poulsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, 1870, Denmark
| | - Peter Ellekvist
- Medical Department, Herlev-Gentofte Hospital, Herlev, 2730, Denmark
| | - Claus Helix-Nielsen
- Aquaporin A/S, Kgs Lyngby, 2800, Denmark.,Department of Environmental Engineering, Technical University of Denmark, Kgs Lyngby, 2800, Denmark.,University of Maribor, Laboratory for Water Biophysics and Membrane Technology, Maribor, 2000, Slovenia
| | - Nirbhay Kumar
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington DC, 20052-0066, USA
| | - Dan A Klaerke
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, 1870, Denmark.
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10
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Borges-Pereira L, Thomas SJ, Dos Anjos E Silva AL, Bartlett PJ, Thomas AP, Garcia CRS. The genetic Ca 2+ sensor GCaMP3 reveals multiple Ca 2+ stores differentially coupled to Ca 2+ entry in the human malaria parasite Plasmodium falciparum. J Biol Chem 2020; 295:14998-15012. [PMID: 32848018 DOI: 10.1074/jbc.ra120.014906] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/12/2020] [Indexed: 12/31/2022] Open
Abstract
Cytosolic Ca2+ regulates multiple steps in the host-cell invasion, growth, proliferation, and egress of blood-stage Plasmodium falciparum, yet our understanding of Ca2+ signaling in this endemic malaria parasite is incomplete. By using a newly generated transgenic line of P. falciparum (PfGCaMP3) that expresses constitutively the genetically encoded Ca2+ indicator GCaMP3, we have investigated the dynamics of Ca2+ release and influx elicited by inhibitors of the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase pumps, cyclopiazonic acid (CPA), and thapsigargin (Thg). Here we show that in isolated trophozoite phase parasites: (i) both CPA and Thg release Ca2+ from intracellular stores in P. falciparum parasites; (ii) Thg is able to induce Ca2+ release from an intracellular compartment insensitive to CPA; (iii) only Thg is able to activate Ca2+ influx from extracellular media, through a mechanism resembling store-operated Ca2+ entry, typical of mammalian cells; and (iv) the Thg-sensitive Ca2+ pool is unaffected by collapsing the mitochondria membrane potential with the uncoupler carbonyl cyanide m-chlorophenyl hydrazone or the release of acidic Ca2+ stores with nigericin. These data suggest the presence of two Ca2+ pools in P. falciparum with differential sensitivity to the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase pump inhibitors, and only the release of the Thg-sensitive Ca2+ store induces Ca2+ influx. Activation of the store-operated Ca2+ entry-like Ca2+ influx may be relevant for controlling processes such as parasite invasion, egress, and development mediated by kinases, phosphatases, and proteases that rely on Ca2+ levels for their activation.
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Affiliation(s)
- Lucas Borges-Pereira
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brasil; Department of Pharmacology, Physiology and Neuroscience, Rutgers University, New Jersey Medical School, Newark, New Jersey, USA
| | - Samantha J Thomas
- Department of Pharmacology, Physiology and Neuroscience, Rutgers University, New Jersey Medical School, Newark, New Jersey, USA
| | | | - Paula J Bartlett
- Department of Pharmacology, Physiology and Neuroscience, Rutgers University, New Jersey Medical School, Newark, New Jersey, USA
| | - Andrew P Thomas
- Department of Pharmacology, Physiology and Neuroscience, Rutgers University, New Jersey Medical School, Newark, New Jersey, USA.
| | - Célia R S Garcia
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brasil.
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11
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Martin RE. The transportome of the malaria parasite. Biol Rev Camb Philos Soc 2019; 95:305-332. [PMID: 31701663 DOI: 10.1111/brv.12565] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 10/02/2019] [Accepted: 10/04/2019] [Indexed: 12/15/2022]
Abstract
Membrane transport proteins, also known as transporters, control the movement of ions, nutrients, metabolites, and waste products across the membranes of a cell and are central to its biology. Proteins of this type also serve as drug targets and are key players in the phenomenon of drug resistance. The malaria parasite has a relatively reduced transportome, with only approximately 2.5% of its genes encoding transporters. Even so, assigning functions and physiological roles to these proteins, and ascertaining their contributions to drug action and drug resistance, has been very challenging. This review presents a detailed critique and synthesis of the disruption phenotypes, protein subcellular localisations, protein functions (observed or predicted), and links to antimalarial drug resistance for each of the parasite's transporter genes. The breadth and depth of the gene disruption data are particularly impressive, with at least one phenotype determined in the parasite's asexual blood stage for each transporter gene, and multiple phenotypes available for 76% of the genes. Analysis of the curated data set revealed there to be relatively little redundancy in the Plasmodium transportome; almost two-thirds of the parasite's transporter genes are essential or required for normal growth in the asexual blood stage of the parasite, and this proportion increased to 78% when the disruption phenotypes available for the other parasite life stages were included in the analysis. These observations, together with the finding that 22% of the transportome is implicated in the parasite's resistance to existing antimalarials and/or drugs within the development pipeline, indicate that transporters are likely to serve, or are already serving, as drug targets. Integration of the different biological and bioinformatic data sets also enabled the selection of candidates for transport processes known to be essential for parasite survival, but for which the underlying proteins have thus far remained undiscovered. These include potential transporters of pantothenate, isoleucine, or isopentenyl diphosphate, as well as putative anion-selective channels that may serve as the pore component of the parasite's 'new permeation pathways'. Other novel insights into the parasite's biology included the identification of transporters for the potential development of antimalarial treatments, transmission-blocking drugs, prophylactics, and genetically attenuated vaccines. The syntheses presented herein set a foundation for elucidating the functions and physiological roles of key members of the Plasmodium transportome and, ultimately, to explore and realise their potential as therapeutic targets.
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Affiliation(s)
- Rowena E Martin
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
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12
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Ashton TD, Devine SM, Möhrle JJ, Laleu B, Burrows JN, Charman SA, Creek DJ, Sleebs BE. The Development Process for Discovery and Clinical Advancement of Modern Antimalarials. J Med Chem 2019; 62:10526-10562. [DOI: 10.1021/acs.jmedchem.9b00761] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Trent D. Ashton
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Shane M. Devine
- Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jörg J. Möhrle
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Benoît Laleu
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Jeremy N. Burrows
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Susan A. Charman
- Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Darren J. Creek
- Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Brad E. Sleebs
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3052, Australia
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13
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Lehane AM, Dennis ASM, Bray KO, Li D, Rajendran E, McCoy JM, McArthur HM, Winterberg M, Rahimi F, Tonkin CJ, Kirk K, van Dooren GG. Characterization of the ATP4 ion pump in Toxoplasma gondii. J Biol Chem 2019; 294:5720-5734. [PMID: 30723156 DOI: 10.1074/jbc.ra118.006706] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/31/2019] [Indexed: 12/22/2022] Open
Abstract
The Plasmodium falciparum ATPase PfATP4 is the target of a diverse range of antimalarial compounds, including the clinical drug candidate cipargamin. PfATP4 was originally annotated as a Ca2+ transporter, but recent evidence suggests that it is a Na+ efflux pump, extruding Na+ in exchange for H+ Here we demonstrate that ATP4 proteins belong to a clade of P-type ATPases that are restricted to apicomplexans and their closest relatives. We employed a variety of genetic and physiological approaches to investigate the ATP4 protein of the apicomplexan Toxoplasma gondii, TgATP4. We show that TgATP4 is a plasma membrane protein. Knockdown of TgATP4 had no effect on resting pH or Ca2+ but rendered parasites unable to regulate their cytosolic Na+ concentration ([Na+]cyt). PfATP4 inhibitors caused an increase in [Na+]cyt and a cytosolic alkalinization in WT but not TgATP4 knockdown parasites. Parasites in which TgATP4 was knocked down or disrupted exhibited a growth defect, attributable to reduced viability of extracellular parasites. Parasites in which TgATP4 had been disrupted showed reduced virulence in mice. These results provide evidence for ATP4 proteins playing a key conserved role in Na+ regulation in apicomplexan parasites.
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Affiliation(s)
- Adele M Lehane
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia,
| | - Adelaide S M Dennis
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Katherine O Bray
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Dongdi Li
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Esther Rajendran
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - James M McCoy
- the Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC 3052, Australia, and.,the Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Hillary M McArthur
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Markus Winterberg
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Farid Rahimi
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Christopher J Tonkin
- the Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC 3052, Australia, and.,the Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Kiaran Kirk
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia,
| | - Giel G van Dooren
- From the Research School of Biology, Australian National University, Canberra, ACT 2601, Australia,
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14
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Rosling JEO, Ridgway MC, Summers RL, Kirk K, Lehane AM. Biochemical characterization and chemical inhibition of PfATP4-associated Na +-ATPase activity in Plasmodium falciparum membranes. J Biol Chem 2018; 293:13327-13337. [PMID: 29986883 DOI: 10.1074/jbc.ra118.003640] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/26/2018] [Indexed: 11/06/2022] Open
Abstract
The antimalarial activity of chemically diverse compounds, including the clinical candidate cipargamin, has been linked to the ATPase PfATP4 in the malaria-causing parasite Plasmodium falciparum The characterization of PfATP4 has been hampered by the inability thus far to achieve its functional expression in a heterologous system. Here, we optimized a membrane ATPase assay to probe the function of PfATP4 and its chemical sensitivity. We found that cipargamin inhibited the Na+-dependent ATPase activity present in P. falciparum membranes from WT parasites and that its potency was reduced in cipargamin-resistant PfATP4-mutant parasites. The cipargamin-sensitive fraction of membrane ATPase activity was inhibited by all 28 of the compounds in the "Malaria Box" shown previously to disrupt ion regulation in P. falciparum in a cipargamin-like manner. This is consistent with PfATP4 being the direct target of these compounds. Characterization of the cipargamin-sensitive ATPase activity yielded data consistent with PfATP4 being a Na+ transporter that is sensitive to physiologically relevant perturbations of pH, but not of [K+] or [Ca2+]. With an apparent Km for ATP of 0.2 mm and an apparent Km for Na+ of 16-17 mm, the protein is predicted to operate at below its half-maximal rate under normal physiological conditions, allowing the rate of Na+ efflux to increase in response to an increase in cytosolic [Na+]. In membranes from a cipargamin-resistant PfATP4-mutant line, the apparent Km for Na+ is slightly elevated. Our study provides new insights into the biochemical properties and chemical sensitivity of an important new antimalarial drug target.
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Affiliation(s)
- James E O Rosling
- From the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Melanie C Ridgway
- From the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Robert L Summers
- From the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Kiaran Kirk
- From the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Adele M Lehane
- From the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
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15
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Dennis ASM, Rosling JEO, Lehane AM, Kirk K. Diverse antimalarials from whole-cell phenotypic screens disrupt malaria parasite ion and volume homeostasis. Sci Rep 2018; 8:8795. [PMID: 29892073 PMCID: PMC5995868 DOI: 10.1038/s41598-018-26819-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 05/14/2018] [Indexed: 11/17/2022] Open
Abstract
Four hundred structurally diverse drug-like compounds comprising the Medicines for Malaria Venture's 'Pathogen Box' were screened for their effect on a range of physiological parameters in asexual blood-stage malaria (Plasmodium falciparum) parasites. Eleven of these compounds were found to perturb parasite Na+, pH and volume in a manner consistent with inhibition of the putative Na+ efflux P-type ATPase PfATP4. All eleven compounds fell within the subset of 125 compounds included in the Pathogen Box on the basis of their having been identified as potent inhibitors of the growth of asexual blood-stage P. falciparum parasites. All eleven compounds inhibited the Na+-dependent ATPase activity of parasite membranes and showed reduced efficacy against parasites carrying mutations in PfATP4. This study increases the number of chemically diverse structures known to show a 'PfATP4-associated' phenotype, and adds to emerging evidence that a high proportion (7-9%) of the structurally diverse antimalarial compounds identified in whole cell phenotypic screens share the same mechanism of action, exerting their antimalarial effect via an interaction with PfATP4.
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Affiliation(s)
- Adelaide S M Dennis
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - James E O Rosling
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Adele M Lehane
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia.
| | - Kiaran Kirk
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia.
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16
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Suárez-Cortés P, Gambara G, Favia A, Palombi F, Alano P, Filippini A. Ned-19 inhibition of parasite growth and multiplication suggests a role for NAADP mediated signalling in the asexual development of Plasmodium falciparum. Malar J 2017; 16:366. [PMID: 28899381 PMCID: PMC5596470 DOI: 10.1186/s12936-017-2013-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 09/04/2017] [Indexed: 11/26/2022] Open
Abstract
Background Although malaria is a preventable and curable human disease, millions of people risk to be infected by the Plasmodium parasites and to develop this illness. Therefore, there is an urgent need to identify new anti-malarial drugs. Ca2+ signalling regulates different processes in the life cycle of Plasmodium falciparum, representing a suitable target for the development of new drugs. Results This study investigated for the first time the effect of a highly specific inhibitor of nicotinic acid adenine dinucleotide phosphate (NAADP)-induced Ca2+ release (Ned-19) on P. falciparum, revealing the inhibitory effect of this compound on the blood stage development of this parasite. Ned-19 inhibits both the transition of the parasite from the early to the late trophozoite stage and the ability of the late trophozoite to develop to the multinucleated schizont stage. In addition, Ned-19 affects spontaneous intracellular Ca2+ oscillations in ring and trophozoite stage parasites, suggesting that the observed inhibitory effects may be associated to regulation of intracellular Ca2+ levels. Conclusions This study highlights the inhibitory effect of Ned-19 on progression of the asexual life cycle of P. falciparum. The observation that Ned-19 inhibits spontaneous Ca2+ oscillations suggests a potential role of NAADP in regulating Ca2+ signalling of P. falciparum. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-2013-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pablo Suárez-Cortés
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Viale Regina Elena n. 299, 00161, Rome, Italy.,Department of Vector Biology, Max-Planck Institute for Infection Biology, Charitéplatz 1, 10117, Berlin, Germany
| | - Guido Gambara
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Annarita Favia
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy.,Nucleic Acids Laboratory, Institute of Molecular Biology and Pathology, National Research Council (IBPM-CNR), Department of Biology and Biotechnologies, Sapienza University, Rome, Italy
| | - Fioretta Palombi
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Viale Regina Elena n. 299, 00161, Rome, Italy.
| | - Antonio Filippini
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy.
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17
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Soni R, Sharma D, Rai P, Sharma B, Bhatt TK. Signaling Strategies of Malaria Parasite for Its Survival, Proliferation, and Infection during Erythrocytic Stage. Front Immunol 2017; 8:349. [PMID: 28400771 PMCID: PMC5368685 DOI: 10.3389/fimmu.2017.00349] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/10/2017] [Indexed: 12/22/2022] Open
Abstract
Irrespective of various efforts, malaria persist the most debilitating effect in terms of morbidity and mortality. Moreover, the existing drugs are also vulnerable to the emergence of drug resistance. To explore the potential targets for designing the most effective antimalarial therapies, it is required to focus on the facts of biochemical mechanism underlying the process of parasite survival and disease pathogenesis. This review is intended to bring out the existing knowledge about the functions and components of the major signaling pathways such as kinase signaling, calcium signaling, and cyclic nucleotide-based signaling, serving the various aspects of the parasitic asexual stage and highlighted the Toll-like receptors, glycosylphosphatidylinositol-mediated signaling, and molecular events in cytoadhesion, which elicit the host immune response. This discussion will facilitate a look over essential components for parasite survival and disease progression to be implemented in discovery of novel antimalarial drugs and vaccines.
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Affiliation(s)
- Rani Soni
- Department of Biotechnology, School of Life sciences, Central University of Rajasthan , Ajmer , India
| | - Drista Sharma
- Department of Biotechnology, School of Life sciences, Central University of Rajasthan , Ajmer , India
| | - Praveen Rai
- Department of Biotechnology, School of Life sciences, Central University of Rajasthan , Ajmer , India
| | - Bhaskar Sharma
- Department of Biotechnology, School of Life sciences, Central University of Rajasthan , Ajmer , India
| | - Tarun K Bhatt
- Department of Biotechnology, School of Life sciences, Central University of Rajasthan , Ajmer , India
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18
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Rai P, Sharma D, Soni R, Khatoon N, Sharma B, Bhatt TK. Plasmodium falciparum apicoplast and its transcriptional regulation through calcium signaling. J Microbiol 2017; 55:231-236. [DOI: 10.1007/s12275-017-6525-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/23/2016] [Accepted: 12/23/2016] [Indexed: 12/12/2022]
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19
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Abstract
Some hours after invading the erythrocytes of its human host, the malaria parasite Plasmodium falciparum induces an increase in the permeability of the erythrocyte membrane to monovalent ions. The resulting net influx of Na(+) and net efflux of K(+), down their respective concentration gradients, converts the erythrocyte cytosol from an initially high-K(+), low-Na(+) solution to a high-Na(+), low-K(+) solution. The intraerythrocytic parasite itself exerts tight control over its internal Na(+), K(+), Cl(-), and Ca(2+) concentrations and its intracellular pH through the combined actions of a range of membrane transport proteins. The molecular mechanisms underpinning ion regulation in the parasite are receiving increasing attention, not least because PfATP4, a P-type ATPase postulated to be involved in Na(+) regulation, has emerged as a potential antimalarial drug target, susceptible to inhibition by a wide range of chemically unrelated compounds.
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Affiliation(s)
- Kiaran Kirk
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia;
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20
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Na+ Influx Induced by New Antimalarials Causes Rapid Alterations in the Cholesterol Content and Morphology of Plasmodium falciparum. PLoS Pathog 2016; 12:e1005647. [PMID: 27227970 PMCID: PMC4881962 DOI: 10.1371/journal.ppat.1005647] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/28/2016] [Indexed: 12/27/2022] Open
Abstract
Among the several new antimalarials discovered over the past decade are at least three clinical candidate drugs, each with a distinct chemical structure, that disrupt Na+ homeostasis resulting in a rapid increase in intracellular Na+ concentration ([Na+]i) within the erythrocytic stages of Plasmodium falciparum. At present, events triggered by Na+ influx that result in parasite demise are not well-understood. Here we report effects of two such drugs, a pyrazoleamide and a spiroindolone, on intraerythrocytic P. falciparum. Within minutes following the exposure to these drugs, the trophozoite stage parasite, which normally contains little cholesterol, was made permeant by cholesterol-dependent detergents, suggesting it acquired a substantial amount of the lipid. Consistently, the merozoite surface protein 1 and 2 (MSP1 and MSP2), glycosylphosphotidylinositol (GPI)-anchored proteins normally uniformly distributed in the parasite plasma membrane, coalesced into clusters. These alterations were not observed following drug treatment of P. falciparum parasites adapted to grow in a low [Na+] growth medium. Both cholesterol acquisition and MSP1 coalescence were reversible upon the removal of the drugs, implicating an active process of cholesterol exclusion from trophozoites that we hypothesize is inhibited by high [Na+]i. Electron microscopy of drug-treated trophozoites revealed substantial morphological changes normally seen at the later schizont stage including the appearance of partial inner membrane complexes, dense organelles that resemble "rhoptries" and apparent nuclear division. Together these results suggest that [Na+]i disruptor drugs by altering levels of cholesterol in the parasite, dysregulate trophozoite to schizont development and cause parasite demise.
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21
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Reappraising the effects of artemisinin on the ATPase activity of PfATP6 and SERCA1a E255L expressed in Xenopus laevis oocytes. Nat Struct Mol Biol 2016; 23:1-2. [PMID: 26733217 DOI: 10.1038/nsmb.3156] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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22
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Brochet M, Billker O. Calcium signalling in malaria parasites. Mol Microbiol 2016; 100:397-408. [PMID: 26748879 DOI: 10.1111/mmi.13324] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2016] [Indexed: 12/24/2022]
Abstract
Ca(2+) is a ubiquitous intracellular messenger in malaria parasites with important functions in asexual blood stages responsible for malaria symptoms, the preceding liver-stage infection and transmission through the mosquito. Intracellular messengers amplify signals by binding to effector molecules that trigger physiological changes. The characterisation of some Ca(2+) effector proteins has begun to provide insights into the vast range of biological processes controlled by Ca(2+) signalling in malaria parasites, including host cell egress and invasion, protein secretion, motility and cell cycle regulation. Despite the importance of Ca(2+) signalling during the life cycle of malaria parasites, little is known about Ca(2+) homeostasis. Recent findings highlighted that upstream of stage-specific Ca(2+) effectors is a conserved interplay between second messengers to control critical intracellular Ca(2+) signals throughout the life cycle. The identification of the molecular mechanisms integrating stage-transcending mechanisms of Ca(2+) homeostasis in a network of stage-specific regulator and effector pathways now represents a major challenge for a meaningful understanding of Ca(2+) signalling in malaria parasites.
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Affiliation(s)
- Mathieu Brochet
- Faculty of Medicine, Department of Microbiology and Molecular Medicine, University of Geneva, 1 Rue Michel-Servet, CH-1211 Geneva 4, Switzerland.,UMR5235 CNRS-Université Montpellier 2, 34095, Montpellier, France
| | - Oliver Billker
- Wellcome Trust Sanger Institute, Malaria Programme, CB10 1SA, Hinxton, UK
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23
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Spiroindolone NITD609 is a novel antimalarial drug that targets the P-type ATPase PfATP4. Future Med Chem 2016; 8:227-38. [PMID: 26824174 DOI: 10.4155/fmc.15.177] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Malaria is caused by the Plasmodium parasite and is a major health problem leading to many deaths worldwide. Lack of a vaccine and increasing drug resistance highlights the need for new antimalarial drugs with novel targets. Antiplasmodial activity of spiroindolones was discovered through whole-cell, phenotypic screening methods. Optimization of the lead spiroindolone improved both potency and pharmacokinetic properties leading to drug candidate NITD609 which has produced encouraging results in clinical trials. Spiroindolones inhibit PfATP4, a P-type Na(+)-ATPase in the plasma membrane of the parasite, causing a fatal disruption of its sodium homeostasis. Other diverse compounds from the Malaria Box appear to target PfATP4 warranting further research into its structure and binding with NITD609 and other potential antimalarial drugs.
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24
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Spillman NJ, Kirk K. The malaria parasite cation ATPase PfATP4 and its role in the mechanism of action of a new arsenal of antimalarial drugs. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2015; 5:149-62. [PMID: 26401486 PMCID: PMC4559606 DOI: 10.1016/j.ijpddr.2015.07.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 07/03/2015] [Accepted: 07/08/2015] [Indexed: 11/28/2022]
Abstract
The intraerythrocytic malaria parasite, Plasmodium falciparum, maintains a low cytosolic Na(+) concentration and the plasma membrane P-type cation translocating ATPase 'PfATP4' has been implicated as playing a key role in this process. PfATP4 has been the subject of significant attention in recent years as mutations in this protein confer resistance to a growing number of new antimalarial compounds, including the spiroindolones, the pyrazoles, the dihydroisoquinolones, and a number of the antimalarial agents in the Medicines for Malaria Venture's 'Malaria Box'. On exposure of parasites to these compounds there is a rapid disruption of cytosolic Na(+). Whether, and if so how, such chemically distinct compounds interact with PfATP4, and how such interactions lead to parasite death, is not yet clear. The fact that multiple different chemical classes have converged upon PfATP4 highlights its significance as a potential target for new generation antimalarial agents. A spiroindolone (KAE609, now known as cipargamin) has progressed through Phase I and IIa clinical trials with favourable results. In this review we consider the physiological role of PfATP4, summarise the current repertoire of antimalarial compounds for which PfATP4 is implicated in their mechanism of action, and provide an outlook on translation from target identification in the laboratory to patient treatment in the field.
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Affiliation(s)
- Natalie Jane Spillman
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia ; Department of Medicine (Infectious Diseases), Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Kiaran Kirk
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
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25
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Abstract
Despite substantial scientific progress over the past two decades, malaria remains a worldwide burden that causes hundreds of thousands of deaths every year. New, affordable and safe drugs are required to overcome increasing resistance against artemisinin-based treatments, treat vulnerable populations, interrupt the parasite life cycle by blocking transmission to the vectors, prevent infection and target malaria species that transiently remain dormant in the liver. In this Review, we discuss how the antimalarial drug discovery pipeline has changed over the past 10 years, grouped by the various target compound or product profiles, to assess progress and gaps, and to recommend priorities.
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Vaidya AB, Morrisey JM, Zhang Z, Das S, Daly TM, Otto TD, Spillman NJ, Wyvratt M, Siegl P, Marfurt J, Wirjanata G, Sebayang BF, Price RN, Chatterjee A, Nagle A, Stasiak M, Charman SA, Angulo-Barturen I, Ferrer S, Belén Jiménez-Díaz M, Martínez MS, Gamo FJ, Avery VM, Ruecker A, Delves M, Kirk K, Berriman M, Kortagere S, Burrows J, Fan E, Bergman LW. Pyrazoleamide compounds are potent antimalarials that target Na+ homeostasis in intraerythrocytic Plasmodium falciparum. Nat Commun 2014; 5:5521. [PMID: 25422853 PMCID: PMC4263321 DOI: 10.1038/ncomms6521] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 10/09/2014] [Indexed: 01/01/2023] Open
Abstract
The quest for new antimalarial drugs, especially those with novel modes of action, is essential in the face of emerging drug-resistant parasites. Here we describe a new chemical class of molecules, pyrazoleamides, with potent activity against human malaria parasites and showing remarkably rapid parasite clearance in an in vivo model. Investigations involving pyrazoleamide-resistant parasites, whole-genome sequencing and gene transfers reveal that mutations in two proteins, a calcium-dependent protein kinase (PfCDPK5) and a P-type cation-ATPase (PfATP4), are necessary to impart full resistance to these compounds. A pyrazoleamide compound causes a rapid disruption of Na+ regulation in blood-stage Plasmodium falciparum parasites. Similar effect on Na+ homeostasis was recently reported for spiroindolones, which are antimalarials of a chemical class quite distinct from pyrazoleamides. Our results reveal that disruption of Na+ homeostasis in malaria parasites is a promising mode of antimalarial action mediated by at least two distinct chemical classes. Novel antimalarial drugs are urgently needed to combat parasite drug resistance. Here, Vaidya et al. describe a new chemical class of potent antimalarial compounds that act by disrupting the parasite's sodium homeostasis.
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Affiliation(s)
- Akhil B Vaidya
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Joanne M Morrisey
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Zhongsheng Zhang
- Department of Biochemistry, University of Washington, Box 357350, Seattle, Washington 98195, USA
| | - Sudipta Das
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Thomas M Daly
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB101SA, UK
| | - Natalie J Spillman
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Matthew Wyvratt
- Medicines for Malaria Venture, PO Box 1826, 20Rt de Pr-Bois, Geneva 15 1215, Switzerland
| | - Peter Siegl
- Medicines for Malaria Venture, PO Box 1826, 20Rt de Pr-Bois, Geneva 15 1215, Switzerland
| | - Jutta Marfurt
- Division of Global and Tropical Health, Menzies School of Health Research and Charles Darwin University, PO Box 41096, Casuarina, Northern Territory 0811, Australia
| | - Grennady Wirjanata
- Division of Global and Tropical Health, Menzies School of Health Research and Charles Darwin University, PO Box 41096, Casuarina, Northern Territory 0811, Australia
| | - Boni F Sebayang
- Eijkman Institute for Molecular Biology, Jl. Diponegoro 69, Jakarta 10430, Indonesia
| | - Ric N Price
- 1] Division of Global and Tropical Health, Menzies School of Health Research and Charles Darwin University, PO Box 41096, Casuarina, Northern Territory 0811, Australia [2] Nuffield Department of Clinical Medicine, Centre for Tropical Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Arnab Chatterjee
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, USA
| | - Advait Nagle
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, USA
| | - Marcin Stasiak
- Department of Biochemistry, University of Washington, Box 357350, Seattle, Washington 98195, USA
| | - Susan A Charman
- Center for Drug Candidate Optimisation, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Iñigo Angulo-Barturen
- GlaxoSmithKline, Malaria Support Group, Calle Severo Ochoa 2, Tres Cantos 28760, Spain
| | - Santiago Ferrer
- GlaxoSmithKline, Malaria Support Group, Calle Severo Ochoa 2, Tres Cantos 28760, Spain
| | | | - María Santos Martínez
- GlaxoSmithKline, Malaria Support Group, Calle Severo Ochoa 2, Tres Cantos 28760, Spain
| | - Francisco Javier Gamo
- GlaxoSmithKline, Malaria Support Group, Calle Severo Ochoa 2, Tres Cantos 28760, Spain
| | - Vicky M Avery
- Eskitis Institute, Griffith University, Don Young Road, Nathan, Queensland 4111, Australia
| | - Andrea Ruecker
- Department of Life Sciences, South Kensington Campus, Imperial College, London SW7 2AZ, UK
| | - Michael Delves
- Department of Life Sciences, South Kensington Campus, Imperial College, London SW7 2AZ, UK
| | - Kiaran Kirk
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | | | - Sandhya Kortagere
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
| | - Jeremy Burrows
- Medicines for Malaria Venture, PO Box 1826, 20Rt de Pr-Bois, Geneva 15 1215, Switzerland
| | - Erkang Fan
- Department of Biochemistry, University of Washington, Box 357350, Seattle, Washington 98195, USA
| | - Lawrence W Bergman
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 190129, USA
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Affiliation(s)
- David S Barnett
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States
| | - R Kiplin Guy
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States
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Lehane AM, Ridgway MC, Baker E, Kirk K. Diverse chemotypes disrupt ion homeostasis in the Malaria parasite. Mol Microbiol 2014; 94:327-39. [PMID: 25145582 DOI: 10.1111/mmi.12765] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2014] [Indexed: 01/09/2023]
Abstract
The antimalarial spiroindolones disrupt Plasmodium falciparum Na(+) regulation and induce an alkalinization of the parasite cytosol. It has been proposed that they do so by inhibiting PfATP4, a parasite plasma membrane P-type ATPase postulated to export Na(+) and import H(+) equivalents. Here, we screened the 400 antiplasmodial compounds of the open access 'Malaria Box' for their effects on parasite ion regulation. Twenty eight compounds affected parasite Na(+) and pH regulation in a manner consistent with PfATP4 inhibition. Six of these, with chemically diverse structures, were selected for further analysis. All six showed reduced antiplasmodial activity against spiroindolone-resistant parasites carrying mutations in pfatp4. We exposed parasites to incrementally increasing concentrations of two of the six compounds and in both cases obtained resistant parasites with mutations in pfatp4. The finding that diverse chemotypes have an apparently similar mechanism of action indicates that PfATP4 may be a significant Achilles' heel for the parasite.
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Affiliation(s)
- Adele M Lehane
- Research School of Biology, Australian National University, Canberra, ACT, 0200, Australia
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Abstract
As it grows and replicates within the erythrocytes of its host the malaria parasite takes up nutrients from the extracellular medium, exports metabolites and maintains a tight control over its internal ionic composition. These functions are achieved via membrane transport proteins, integral membrane proteins that mediate the passage of solutes across the various membranes that separate the biochemical machinery of the parasite from the extracellular environment. Proteins of this type play a key role in antimalarial drug resistance, as well as being candidate drug targets in their own right. This review provides an overview of recent work on the membrane transport biology of the malaria parasite-infected erythrocyte, encompassing both the parasite-induced changes in the membrane transport properties of the host erythrocyte and the cell physiology of the intracellular parasite itself.
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Krishna S, Pulcini S, Moore CM, Teo BHY, Staines HM. Pumped up: reflections on PfATP6 as the target for artemisinins. Trends Pharmacol Sci 2014; 35:4-11. [DOI: 10.1016/j.tips.2013.10.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 10/11/2013] [Accepted: 10/21/2013] [Indexed: 12/01/2022]
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Flannery EL, Fidock DA, Winzeler EA. Using genetic methods to define the targets of compounds with antimalarial activity. J Med Chem 2013; 56:7761-71. [PMID: 23927658 DOI: 10.1021/jm400325j] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although phenotypic cellular screening has been used to drive antimalarial drug discovery in recent years, in some cases target-based drug discovery remains more attractive. This is especially true when appropriate high-throughput cellular assays are lacking, as is the case for drug discovery efforts that aim to provide a replacement for primaquine (4-N-(6-methoxyquinolin-8-yl)pentane-1,4-diamine), the only drug that can block Plasmodium transmission to Anopheles mosquitoes and eliminate liver-stage hypnozoites. At present, however, there are no known chemically validated parasite protein targets that are important in all Plasmodium parasite developmental stages and that can be used in traditional biochemical compound screens. We propose that a plethora of novel, chemically validated, cross-stage antimalarial targets still remain to be discovered from the ~5,500 proteins encoded by the Plasmodium genomes. Here we discuss how in vitro evolution of drug-resistant strains of Plasmodium falciparum and subsequent whole-genome analysis can be used to find the targets of some of the many compounds discovered in whole-cell phenotypic screens.
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Affiliation(s)
- Erika L Flannery
- Department of Pediatrics, University of California, San Diego, School of Medicine , 9500 Gilman Drive 0741, La Jolla, California 92093, United States
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Spillman NJ, Allen RJW, McNamara CW, Yeung BKS, Winzeler EA, Diagana TT, Kirk K. Na(+) regulation in the malaria parasite Plasmodium falciparum involves the cation ATPase PfATP4 and is a target of the spiroindolone antimalarials. Cell Host Microbe 2013; 13:227-37. [PMID: 23414762 PMCID: PMC3574224 DOI: 10.1016/j.chom.2012.12.006] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 10/28/2012] [Accepted: 12/20/2012] [Indexed: 01/06/2023]
Abstract
The malaria parasite Plasmodium falciparum establishes in the host erythrocyte plasma membrane new permeability pathways that mediate nutrient uptake into the infected cell. These pathways simultaneously allow Na(+) influx, causing [Na(+)] in the infected erythrocyte cytosol to increase to high levels. The intraerythrocytic parasite itself maintains a low cytosolic [Na(+)] via unknown mechanisms. Here we present evidence that the intraerythrocytic parasite actively extrudes Na(+) against an inward gradient via PfATP4, a parasite plasma membrane protein with sequence similarities to Na(+)-ATPases of lower eukaryotes. Mutations in PfATP4 confer resistance to a potent class of antimalarials, the spiroindolones. Consistent with this, the spiroindolones cause a profound disruption in parasite Na(+) homeostasis, which is attenuated in parasites bearing resistance-conferring mutations in PfATP4. The mutant parasites also show some impairment of Na(+) regulation. Taken together, our results are consistent with PfATP4 being a Na(+) efflux ATPase and a target of the spiroindolones.
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Affiliation(s)
- Natalie J Spillman
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
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Progressing the global antimalarial portfolio: finding drugs which target multiple Plasmodium life stages. Parasitology 2013; 141:66-76. [PMID: 23746048 DOI: 10.1017/s0031182013000747] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The number of novel antimalarial candidates entering preclinical development has seen an increase over the last several years. Most of these drug candidates were originally identified as hits coming from screening large chemical libraries specifically targeting the asexual blood stages of Plasmodium falciparum. Indeed, a large proportion of the current antimalarial arsenal has mainly targeted the asexual blood stage which is responsible for clinical symptoms of the disease. However, as part of the eradication agenda and to address resistance, any next-generation antimalarial should have additional activity on at least one other parasite life stage, i.e. gametocytocidal and/or tissue schizonticidal activity. We have applied this approach by screening compounds with intrinsic activity on asexual blood stages in assays against sexual and liver stages and identified two new antimalarial chemotypes with activity on multiple parasite life stages. This strategy can be expanded to identify other chemical classes of molecules with similar activity profiles for the next generation antimalarials. The following review summarizes the discovery of the spiroindolones and imidazolopiperazine classes of antimalarials developed by the NGBS consortium (Novartis Institute for Tropical Diseases, Genomic Institute of the Novartis Research Foundation, Biomedical Primate Research Center, and the Swiss Tropical and Public Health Institute) currently in clinical trials.
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Kotšubei A, Gorgel M, Morth JP, Nissen P, Andersen JL. Probing determinants of cyclopiazonic acid sensitivity of bacterial Ca2+-ATPases. FEBS J 2013; 280:5441-9. [PMID: 23621633 DOI: 10.1111/febs.12310] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/22/2013] [Accepted: 04/24/2013] [Indexed: 01/15/2023]
Abstract
Cyclopiazonic acid (CPA) is a specific and potent inhibitor of the sarcoplasmic reticulum Ca(2+)-ATPase 1a (SERCA1a). Despite high sequence similarity to SERCA1a, Listeria monocytogenes Ca(2+)-ATPase 1 (LMCA1) is not inhibited by CPA. To test whether a CPA binding site could be created while maintaining the functionality of the ATPase we targeted four amino acid positions in LMCA1 for mutational studies based on a multiple sequence alignment of SERCA-like Ca(2+)-ATPases and structural analysis of the CPA site. The identification of CPA-sensitive gain-of-function mutants pinpointed key determinants of the CPA binding site. The importance of these determinants was further underscored by the characterization of the CPA sensitivity of two additional bacterial Ca(2+)-ATPases from Lactococcus lactis and Bacillus cereus. The CPA sensitivity was predicted from their sequence compared with the LMCA1 results, and this was experimentally confirmed. Interestingly, a cluster of Lactococcus bacteria applied in the production of fermented cheese display Ca(2+)-ATPases that are predictably CPA insensitive and may originate from their coexistence with CPA-producing Penicillum and Aspergillus fungi in the cheese. The differences between bacterial and mammalian binding pockets encompassing the CPA site suggest that CPA derivatives that are specific for bacteria or other pathogens can be developed.
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Affiliation(s)
- Aljona Kotšubei
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN, Aarhus University, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Denmark; Department of Gene Technology, Tallinn University of Technology, Estonia
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35
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Spillman NJ, Allen RJ, Kirk K. Na+ extrusion imposes an acid load on the intraerythrocytic malaria parasite. Mol Biochem Parasitol 2013; 189:1-4. [DOI: 10.1016/j.molbiopara.2013.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 04/11/2013] [Accepted: 04/15/2013] [Indexed: 01/02/2023]
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36
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Pulcini S, Staines HM, Pittman JK, Slavic K, Doerig C, Halbert J, Tewari R, Shah F, Avery MA, Haynes RK, Krishna S. Expression in yeast links field polymorphisms in PfATP6 to in vitro artemisinin resistance and identifies new inhibitor classes. J Infect Dis 2013; 208:468-78. [PMID: 23599312 DOI: 10.1093/infdis/jit171] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The mechanism of action of artemisinins against malaria is unclear, despite their widespread use in combination therapies and the emergence of resistance. RESULTS Here, we report expression of PfATP6 (a SERCA pump) in yeast and demonstrate its inhibition by artemisinins. Mutations in PfATP6 identified in field isolates (such as S769N) and in laboratory clones (such as L263E) decrease susceptibility to artemisinins, whereas they increase susceptibility to unrelated inhibitors such as cyclopiazonic acid. As predicted from the yeast model, Plasmodium falciparum with the L263E mutation is also more susceptible to cyclopiazonic acid. An inability to knockout parasite SERCA pumps provides genetic evidence that they are essential in asexual stages of development. Thaperoxides are a new class of potent antimalarial designed to act by inhibiting PfATP6. Results in yeast confirm this inhibition. CONCLUSIONS The identification of inhibitors effective against mutated PfATP6 suggests ways in which artemisinin resistance may be overcome.
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Affiliation(s)
- Serena Pulcini
- Division of Clinical Sciences, St. George's, University of London, UK
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The Plasmodium berghei Ca(2+)/H(+) exchanger, PbCAX, is essential for tolerance to environmental Ca(2+) during sexual development. PLoS Pathog 2013; 9:e1003191. [PMID: 23468629 PMCID: PMC3585132 DOI: 10.1371/journal.ppat.1003191] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 12/28/2012] [Indexed: 12/15/2022] Open
Abstract
Ca(2+) contributes to a myriad of important cellular processes in all organisms, including the apicomplexans, Plasmodium and Toxoplasma. Due to its varied and essential roles, free Ca(2+) is tightly regulated by complex mechanisms. These mechanisms are therefore of interest as putative drug targets. One pathway in Ca(2+) homeostatic control in apicomplexans uses a Ca(2+)/H(+) exchanger (a member of the cation exchanger family, CAX). The P. falciparum CAX (PfCAX) has recently been characterised in asexual blood stage parasites. To determine the physiological importance of apicomplexan CAXs, tagging and knock-out strategies were undertaken in the genetically tractable T. gondii and P. berghei parasites. In addition, a yeast heterologous expression system was used to study the function of apicomplexan CAXs. Tagging of T. gondii and P. berghei CAXs (TgCAX and PbCAX) under control of their endogenous promoters could not demonstrate measureable expression of either CAX in tachyzoites and asexual blood stages, respectively. These results were consistent with the ability of parasites to tolerate knock-outs of the genes for TgCAX and PbCAX at these developmental stages. In contrast, PbCAX expression was detectable during sexual stages of development in female gametocytes/gametes, zygotes and ookinetes, where it was dispersed in membranous networks within the cytosol (with minimal mitochondrial localisation). Furthermore, genetically disrupted parasites failed to develop further from "round" form zygotes, suggesting that PbCAX is essential for ookinete development and differentiation. This impeded phenotype could be rescued by removal of extracellular Ca(2+). Therefore, PbCAX provides a mechanism for free living parasites to multiply within the ionic microenvironment of the mosquito midgut. Ca(2+) homeostasis mediated by PbCAX is critical and suggests plasmodial CAXs may be targeted in approaches designed to block parasite transmission.
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Wang J, Zhou G, Ying SH, Feng MG. P-type calcium ATPase functions as a core regulator of Beauveria bassiana growth, conidiation and responses to multiple stressful stimuli through cross-talk with signalling networks. Environ Microbiol 2012. [PMID: 23206243 DOI: 10.1111/1462-2920.12044] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
P-type Ca(2+) -ATPase (Pmr1) is a core element in calcium-calcineurin pathway and evidence for its cross-talk with other signalling pathways in filamentous fungi is of scarcity. Here, we characterized the striking functions of a Golgi Ca(2+) -ATPase (Bbpmr1) in Beauveria bassiana (fungal entomopathogen) by multi-phenotypic and transcriptional analyses under normal and stressful conditions. Bbpmr1 inactivation caused severe defects in nutritional uptake, growth, conidiation and germination under normal conditions, drastic reductions in cell tolerances to oxidative, hyperosmotic, cell wall disturbing and fungicidal stresses and toxic metal ions during colony growth and/or conidial germination, and half loss of the fungal biocontrol potential represented by conidial virulence, thermotolerance and UV-B resistance. Accompanied with the multi-phenotypic defects, four important genes associated with asexual development were repressed by ≥ 75% in ΔBbpmr1 versus wild type, and all or most of stress-responsive genes encoding 14 cascaded proteins in MAPK pathways, two Ras GTPases, two protein kinases, Ssk1-type response regulator, TOR signalling protein, and many downstream enzymes and proteins were greatly downregulated in ΔBbpmr1 under the chemical stresses. Conclusively, Bbpmr1 regulates positively fundamental aspects on B. bassiana biology and environmental adaptation through wide cross-talk with cellular signalling networks including MAPK cascades and those upstream or independent of the cascades.
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Affiliation(s)
- Jie Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China
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Anthony MP, Burrows JN, Duparc S, JMoehrle J, Wells TNC. The global pipeline of new medicines for the control and elimination of malaria. Malar J 2012; 11:316. [PMID: 22958514 PMCID: PMC3472257 DOI: 10.1186/1475-2875-11-316] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 07/21/2012] [Indexed: 12/03/2022] Open
Abstract
Over the past decade, there has been a transformation in the portfolio of medicines to combat malaria. New fixed-dose artemisinin combination therapy is available, with four different types having received approval from Stringent Regulatory Authorities or the World Health Organization (WHO). However, there is still scope for improvement. The Malaria Eradication Research agenda identified several gaps in the current portfolio. Simpler regimens, such as a single-dose cure are needed, compared with the current three-day treatment. In addition, new medicines that prevent transmission and also relapse are needed, but with better safety profiles than current medicines. There is also a big opportunity for new medicines to prevent reinfection and to provide chemoprotection. This study reviews the global portfolio of new medicines in development against malaria, as of the summer of 2012. Cell-based phenotypic screening, and 'fast followers' of clinically validated classes, mean that there are now many new classes of molecules starting in clinical development, especially for the blood stages of malaria. There remain significant gaps for medicines blocking transmission, preventing relapse, and long-duration molecules for chemoprotection. The nascent pipeline of new medicines is significantly stronger than five years ago. However, there are still risks ahead in clinical development and sustainable funding of clinical studies is vital if this early promise is going to be delivered.
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Affiliation(s)
- Melinda P Anthony
- Medicines for Malaria Venture (MMV), 20 rte de Pré-Bois 1215, Geneva, Switzerland
| | - Jeremy N Burrows
- Medicines for Malaria Venture (MMV), 20 rte de Pré-Bois 1215, Geneva, Switzerland
| | - Stephan Duparc
- Medicines for Malaria Venture (MMV), 20 rte de Pré-Bois 1215, Geneva, Switzerland
| | - Joerg JMoehrle
- Medicines for Malaria Venture (MMV), 20 rte de Pré-Bois 1215, Geneva, Switzerland
| | - Timothy NC Wells
- Medicines for Malaria Venture (MMV), 20 rte de Pré-Bois 1215, Geneva, Switzerland
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40
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Salcedo-Sora JE, Ward SA, Biagini GA. A yeast expression system for functional and pharmacological studies of the malaria parasite Ca²⁺/H⁺ antiporter. Malar J 2012; 11:254. [PMID: 22853777 PMCID: PMC3488005 DOI: 10.1186/1475-2875-11-254] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Accepted: 07/23/2012] [Indexed: 12/26/2022] Open
Abstract
Background Calcium (Ca2+) signalling is fundamental for host cell invasion, motility, in vivo synchronicity and sexual differentiation of the malaria parasite. Consequently, cytoplasmic free Ca2+ is tightly regulated through the co-ordinated action of primary and secondary Ca2+ transporters. Identifying selective inhibitors of Ca2+ transporters is key towards understanding their physiological role as well as having therapeutic potential, therefore screening systems to facilitate the search for potential inhibitors are a priority. Here, the methodology for the expression of a Calcium membrane transporter that can be scaled to high throughputs in yeast is presented. Methods The Plasmodium falciparum Ca2+/H+ antiporter (PfCHA) was expressed in the yeast Saccharomyces cerevisiae and its activity monitored by the bioluminescence from apoaequorin triggered by divalent cations, such as calcium, magnesium and manganese. Results Bioluminescence assays demonstrated that PfCHA effectively suppressed induced cytoplasmic peaks of Ca2+, Mg2+ and Mn2+ in yeast mutants lacking the homologue yeast antiporter Vcx1p. In the scalable format of 96-well culture plates pharmacological assays with a cation antiporter inhibitor allowed the measurement of inhibition of the Ca2+ transport activity of PfCHA conveniently translated to the familiar concept of fractional inhibitory concentrations. Furthermore, the cytolocalization of this antiporter in the yeast cells showed that whilst PfCHA seems to locate to the mitochondrion of P. falciparum, in yeast PfCHA is sorted to the vacuole. This facilitates the real-time Ca2+-loading assays for further functional and pharmacological studies. Discussion The functional expression of PfCHA in S. cerevisiae and luminescence-based detection of cytoplasmic cations as presented here offer a tractable system that facilitates functional and pharmacological studies in a high-throughput format. PfCHA is shown to behave as a divalent cation/H+ antiporter susceptible to the effects of cation/H+ inhibitors such as KB-R7943. This type of gene expression systems should advance the efforts for the screening of potential inhibitors of this type of divalent cation transporters as part of the malaria drug discovery initiatives and for functional studies in general. Conclusion The expression and activity of the PfCHA detected in yeast by a bioluminescence assay that follows the levels of cytoplasmic Ca2+ as well as Mg2+ and Mn2+ lend itself to high-throughput and quantitative settings for pharmacological screening and functional studies.
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Rohrbach P. Quantitative fluorescent live cell imaging of intracellular Ca2+ and H+ ions in malaria parasites. Methods Enzymol 2012; 505:469-83. [PMID: 22289468 DOI: 10.1016/b978-0-12-388448-0.00032-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Light microscopy plays an important role in cell biology and has been instrumental in the description of the living world. Fluorescent probes and new advances in microscopic techniques have revolutionized the application, enabling real time investigation of biological processes in 3D living cells using physiological conditions. Current applications of live cell imaging may include quantification of ion concentrations in cellular compartments, monitoring ion fluxes and signaling events, protein sorting and trafficking processes, as well as protein-protein interactions. Because of its potential, live cell imaging has been widely applied to study the biology and pathophysiology of the human malaria parasite Plasmodium falciparum. Apart from its clinical importance, P. falciparum has fascinated the cell biologist because of its ability to exist and develop within an inert cell: the human erythrocyte. Our understanding of intracellular ion regulation in malaria parasites has been greatly enhanced since the introduction of fluorescence microscopy and live cell imaging. This chapter provides an overview of the various fluorescent molecules available to monitor ion homeostasis in this parasite and outline the techniques used for ion quantification.
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Affiliation(s)
- Petra Rohrbach
- Institute of Parasitology, McGill University, Quebec, Canada
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Generation of second messengers in Plasmodium. Microbes Infect 2012; 14:787-95. [PMID: 22584103 DOI: 10.1016/j.micinf.2012.04.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Revised: 04/17/2012] [Accepted: 04/18/2012] [Indexed: 02/05/2023]
Abstract
Signalling in malaria parasites is a field of growing interest as its components may prove to be valuable drug targets, especially when one considers the burden of a disease that is responsible for up to 500 million infections annually. The scope of this review is to discuss external stimuli in the parasite life cycle and the upstream machinery responsible for translating them into intracellular responses, focussing particularly on the calcium signalling pathway.
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Bartolommei G, Tadini-Buoninsegni F, Moncelli MR, Gemma S, Camodeca C, Butini S, Campiani G, Lewis D, Inesi G. The Ca2+-ATPase (SERCA1) is inhibited by 4-aminoquinoline derivatives through interference with catalytic activation by Ca2+, whereas the ATPase E2 state remains functional. J Biol Chem 2011; 286:38383-38389. [PMID: 21914795 DOI: 10.1074/jbc.m111.287276] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Several clotrimazole (CLT) and 4-aminoquinoline derivatives were synthesized and found to exhibit in vitro antiplasmodial activity with IC(50) ranging from nm to μm values. We report here that some of these compounds produce inhibition of rabbit sarcoplasmic reticulum Ca(2+)-ATPase (SERCA1) with IC(50) values in the μm range. The highest affinity for the Ca(2+)-ATPase was observed with NF1442 (N-((3-chlorophenyl)(4-((4-(7-chloroquinolin-4-yl)piperazin-1-yl)methyl)phenyl)methyl)-7-chloro-4-aminoquinoline) and NF1058 (N-((3-chlorophenyl)(4-(pyrrolidin-1-ylmethyl)phenyl)methyl)-7-chloro-4-aminoquinoline),yielding IC(50) values of 1.3 and 8.0 μm as demonstrated by measurements of steady state ATPase activity as well as single cycle charge transfer. Characterization of sequential reactions comprising the ATPase catalytic and transport cycle then demonstrated that NF1058, and similarly CLT, interferes with the mechanism of Ca(2+) binding and Ca(2+)-dependent enzyme activation (E(2) to E(1)·Ca(2) transition) required for formation of phosphorylated intermediate by ATP utilization. On the other hand, Ca(2+) independent phosphoenzyme formation by utilization of P(i) (i.e. reverse of the hydrolytic reaction in the absence of Ca(2+)) was not inhibited by NF1058 or CLT. Comparative experiments showed that the high affinity inhibitor thapsigargin interferes not only with Ca(2+) binding and phosphoenzyme formation with ATP but also with phosphoenzyme formation by utilization of P(i) even though this reaction does not require Ca(2+). It is concluded that NF1058 and CLT inhibit SERCA by stabilization of an E(2) state that, as opposed to that obtained with thapsigargin, retains the functional ability to form E(2)-P by reacting with P(i).
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Affiliation(s)
- Gianluca Bartolommei
- Department of Chemistry "Ugo Schiff," University of Florence, 50019 Sesto Fiorentino, Italy
| | | | - Maria Rosa Moncelli
- Department of Chemistry "Ugo Schiff," University of Florence, 50019 Sesto Fiorentino, Italy
| | - Sandra Gemma
- European Research Centre for Drug Discovery and Development and Department of Pharmaceutical and Applied Chemistry, University of Siena, 53100 Siena, Italy
| | - Caterina Camodeca
- European Research Centre for Drug Discovery and Development and Department of Pharmaceutical and Applied Chemistry, University of Siena, 53100 Siena, Italy
| | - Stefania Butini
- European Research Centre for Drug Discovery and Development and Department of Pharmaceutical and Applied Chemistry, University of Siena, 53100 Siena, Italy
| | - Giuseppe Campiani
- European Research Centre for Drug Discovery and Development and Department of Pharmaceutical and Applied Chemistry, University of Siena, 53100 Siena, Italy
| | - David Lewis
- California Pacific Medical Center Research Institute, San Francisco, California 94107
| | - Giuseppe Inesi
- California Pacific Medical Center Research Institute, San Francisco, California 94107
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Rottmann M, McNamara C, Yeung BKS, Lee MCS, Zou B, Russell B, Seitz P, Plouffe DM, Dharia NV, Tan J, Cohen SB, Spencer KR, González-Páez GE, Lakshminarayana SB, Goh A, Suwanarusk R, Jegla T, Schmitt EK, Beck HP, Brun R, Nosten F, Renia L, Dartois V, Keller TH, Fidock DA, Winzeler EA, Diagana TT. Spiroindolones, a potent compound class for the treatment of malaria. Science 2010; 329:1175-80. [PMID: 20813948 PMCID: PMC3050001 DOI: 10.1126/science.1193225] [Citation(s) in RCA: 907] [Impact Index Per Article: 64.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Recent reports of increased tolerance to artemisinin derivatives--the most recently adopted class of antimalarials--have prompted a need for new treatments. The spirotetrahydro-beta-carbolines, or spiroindolones, are potent drugs that kill the blood stages of Plasmodium falciparum and Plasmodium vivax clinical isolates at low nanomolar concentration. Spiroindolones rapidly inhibit protein synthesis in P. falciparum, an effect that is ablated in parasites bearing nonsynonymous mutations in the gene encoding the P-type cation-transporter ATPase4 (PfATP4). The optimized spiroindolone NITD609 shows pharmacokinetic properties compatible with once-daily oral dosing and has single-dose efficacy in a rodent malaria model.
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Affiliation(s)
- Matthias Rottmann
- Swiss Tropical and Public Health Institute, Parasite Chemotherapy, CH-4002 Basel, Switzerland
- University of Basel, CH-4003 Basel, Switzerland
| | - Case McNamara
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | | | - Marcus C. S. Lee
- Department of Microbiology and Immunology, Columbia University Medical Center, NY 10032, USA
| | - Bin Zou
- Novartis Institute for Tropical Diseases, 138670 Singapore
| | - Bruce Russell
- Laboratory of Malaria Immunobiology, Singapore Immunology Network, Agency for Science Technology and Research (ASTAR), Biopolis, Singapore
| | - Patrick Seitz
- Swiss Tropical and Public Health Institute, Parasite Chemotherapy, CH-4002 Basel, Switzerland
- University of Basel, CH-4003 Basel, Switzerland
| | - David M. Plouffe
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Neekesh V. Dharia
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jocelyn Tan
- Novartis Institute for Tropical Diseases, 138670 Singapore
| | - Steven B. Cohen
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Kathryn R. Spencer
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | | | - Anne Goh
- Novartis Institute for Tropical Diseases, 138670 Singapore
| | - Rossarin Suwanarusk
- Laboratory of Malaria Immunobiology, Singapore Immunology Network, Agency for Science Technology and Research (ASTAR), Biopolis, Singapore
| | - Tim Jegla
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Esther K. Schmitt
- Natural Products Unit, Novartis Pharma AG, CH-4002 Basel, Switzerland
| | - Hans-Peter Beck
- Swiss Tropical and Public Health Institute, Parasite Chemotherapy, CH-4002 Basel, Switzerland
- University of Basel, CH-4003 Basel, Switzerland
| | - Reto Brun
- Swiss Tropical and Public Health Institute, Parasite Chemotherapy, CH-4002 Basel, Switzerland
- University of Basel, CH-4003 Basel, Switzerland
| | - Francois Nosten
- Shoklo Malaria Research Unit, Mae Sot, Tak 63110, Thailand
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, OX3 7LJ, UK
| | - Laurent Renia
- Laboratory of Malaria Immunobiology, Singapore Immunology Network, Agency for Science Technology and Research (ASTAR), Biopolis, Singapore
| | | | | | - David A. Fidock
- Department of Microbiology and Immunology, Columbia University Medical Center, NY 10032, USA
- Department of Medicine (Division of Infectious Diseases), Columbia University Medical Center, NY 10032, USA
| | - Elizabeth A. Winzeler
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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Cardi D, Pozza A, Arnou B, Marchal E, Clausen JD, Andersen JP, Krishna S, Møller JV, le Maire M, Jaxel C. Purified E255L mutant SERCA1a and purified PfATP6 are sensitive to SERCA-type inhibitors but insensitive to artemisinins. J Biol Chem 2010; 285:26406-16. [PMID: 20530490 PMCID: PMC2924071 DOI: 10.1074/jbc.m109.090340] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The antimalarial drugs artemisinins have been described as inhibiting Ca(2+)-ATPase activity of PfATP6 (Plasmodium falciparum ATP6) after expression in Xenopus oocytes. Mutation of an amino acid residue in mammalian SERCA1 (Glu(255)) to the equivalent one predicted in PfATP6 (Leu) was reported to induce sensitivity to artemisinin in the oocyte system. However, in the present experiments, we found that artemisinin did not inhibit mammalian SERCA1a E255L either when expressed in COS cells or after purification of the mutant expressed in Saccharomyces cerevisiae. Moreover, we found that PfATP6 after expression and purification from S. cerevisiae was insensitive to artemisinin and significantly less sensitive to thapsigargin and 2,5-di(tert-butyl)-1,4-benzohydroquinone than rabbit SERCA1 but retained higher sensitivity to cyclopiazonic acid, another type of SERCA1 inhibitor. Although mammalian SERCA and purified PfATP6 appear to have different pharmacological profiles, their insensitivity to artemisinins suggests that the mechanism of action of this class of drugs on the calcium metabolism in the intact cell is complex and cannot be ascribed to direct inhibition of PfATP6. Furthermore, the successful purification of PfATP6 affords the opportunity to develop new antimalarials by screening for inhibitors against PfATP6.
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Affiliation(s)
- Delphine Cardi
- Commissariat à l'Energie Atomique, Institut de Biologie et de Technologies de Saclay, SB2SM, France
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46
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Exploiting the therapeutic potential of Plasmodium falciparum solute transporters. Trends Parasitol 2010; 26:284-96. [DOI: 10.1016/j.pt.2010.03.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 03/02/2010] [Accepted: 03/05/2010] [Indexed: 01/16/2023]
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Abstract
The malaria parasite-infected erythrocyte is a multi-compartment structure, incorporating numerous different membrane systems. The movement of nutrients, metabolites and inorganic ions into and out of the intraerythrocytic parasite, as well as between subcellular compartments within the parasite, is mediated by transporters and channels - integral membrane proteins that facilitate the movement of solutes across the membrane bilayer. Proteins of this type also play a key role in antimalarial drug resistance. Genes encoding transporters and channels account for at least 2.5% of the parasite genome. However, ascribing functions and physiological roles to these proteins, and defining their roles in drug resistance, is not straightforward. For any given membrane transport protein, a full understanding of its role(s) in the parasitized erythrocyte requires a knowledge of its subcellular localization and substrate specificity, as well as some knowledge of the effects on the parasite of modifying the sequence and/or level of expression of the gene involved. Here we consider recent work in this area, describe a number of newly identified transport proteins, and summarize the likely subcellular localization and putative substrate specificity of all of the candidate membrane transport proteins identified to date.
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Affiliation(s)
- Rowena E Martin
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia.
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49
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Vangheluwe P, Sepúlveda MR, Missiaen L, Raeymaekers L, Wuytack F, Vanoevelen J. Intracellular Ca2+- and Mn2+-Transport ATPases. Chem Rev 2009; 109:4733-59. [DOI: 10.1021/cr900013m] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Peter Vangheluwe
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - M. Rosario Sepúlveda
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Ludwig Missiaen
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Luc Raeymaekers
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Frank Wuytack
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Jo Vanoevelen
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
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50
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Rohrbach P. Imaging ion flux and ion homeostasis in blood stage malaria parasites. Biotechnol J 2009; 4:812-25. [DOI: 10.1002/biot.200900084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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