1
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Luo AP, Giannangelo C, Siddiqui G, Creek DJ. Promising antimalarial hits from phenotypic screens: a review of recently-described multi-stage actives and their modes of action. Front Cell Infect Microbiol 2023; 13:1308193. [PMID: 38162576 PMCID: PMC10757594 DOI: 10.3389/fcimb.2023.1308193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 11/29/2023] [Indexed: 01/03/2024] Open
Abstract
Over the last two decades, global malaria cases caused by Plasmodium falciparum have declined due to the implementation of effective treatments and the use of insecticides. However, the COVID-19 pandemic caused major disruption in the timely delivery of medical goods and diverted public health resources, impairing malaria control. The emergence of resistance to all existing frontline antimalarials underpins an urgent need for new antimalarials with novel mechanisms of action. Furthermore, the need to reduce malaria transmission and/or prevent malaria infection has shifted the focus of antimalarial research towards the discovery of compounds that act beyond the symptomatic blood stage and also impact other parasite life cycle stages. Phenotypic screening has been responsible for the majority of new antimalarial lead compounds discovered over the past 10 years. This review describes recently reported novel antimalarial hits that target multiple parasite stages and were discovered by phenotypic screening during the COVID-19 pandemic. Their modes of action and targets in blood stage parasites are also discussed.
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Affiliation(s)
| | | | - Ghizal Siddiqui
- Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Darren J. Creek
- Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
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2
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Ramli AH, Mohd Faudzi SM. Diarylpentanoids, the privileged scaffolds in antimalarial and anti-infectives drug discovery: A review. Arch Pharm (Weinheim) 2023; 356:e2300391. [PMID: 37806761 DOI: 10.1002/ardp.202300391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/17/2023] [Accepted: 09/18/2023] [Indexed: 10/10/2023]
Abstract
Asia is a hotspot for infectious diseases, including malaria, dengue fever, tuberculosis, and the pandemic COVID-19. Emerging infectious diseases have taken a heavy toll on public health and the economy and have been recognized as a major cause of morbidity and mortality, particularly in Southeast Asia. Infectious disease control is a major challenge, but many surveillance systems and control strategies have been developed and implemented. These include vector control, combination therapies, vaccine development, and the development of new anti-infectives. Numerous newly discovered agents with pharmacological anti-infective potential are being actively and extensively studied for their bioactivity, toxicity, selectivity, and mode of action, but many molecules lose their efficacy over time due to resistance developments. These facts justify the great importance of the search for new, effective, and safe anti-infectives. Diarylpentanoids, a curcumin derivative, have been developed as an alternative with better bioavailability and metabolism as a therapeutic agent. In this review, the mechanisms of action and potential targets of antimalarial drugs as well as the classes of antimalarial drugs are presented. The bioactivity of diarylpentanoids as a potential scaffold for a new class of anti-infectives and their structure-activity relationships are also discussed in detail.
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Affiliation(s)
- Amirah H Ramli
- Natural Medicines and Products Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
| | - Siti M Mohd Faudzi
- Natural Medicines and Products Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, Serdang, Malaysia
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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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Cui J, Yang X, Yang J, Jia R, Feng Y, Shen B. A Coccidia-Specific Phosphate Transporter Is Essential for the Growth of Toxoplasma gondii Parasites. Microbiol Spectr 2022; 10:e0218622. [PMID: 36094254 PMCID: PMC9604053 DOI: 10.1128/spectrum.02186-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/26/2022] [Indexed: 12/31/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite that acquires all necessary nutrients from the hosts, but the exact nutrient acquisition mechanisms are poorly understood. Here, we identified three putative phosphate transporters in T. gondii. TgPiT and TgPT2 are mainly on the plasma membrane, whereas TgmPT is localized to the mitochondrion. TgPiT and TgmPT are widely present and conserved in apicomplexan parasites that include Plasmodium and Eimeria species. Nonetheless, they are dispensable for the growth and virulence of Toxoplasma. TgPT2, on the other hand, is restricted to coccidia parasites and is essential for Toxoplasma survival. TgPT2 depletion led to reduced motility and invasion, as well as growth arrest of the parasites both in vitro and in vivo. Both TgPiT and TgPT2 have phosphate transport activities and contribute to parasites' inorganic phosphate (Pi) absorption. Interestingly, the Pi importing activity of Toxoplasma parasites could be competitively inhibited by ATP and AMP. Furthermore, direct uptake of 32P-ATP was also observed, indicating the parasites' ability to scavenge host ATP. Nonetheless, ATP/AMP import is not mediated by TgPiT or TgPT2, suggesting additional mechanisms. Together, these results show the complex pathways of phosphate transport in Toxoplasma, and TgPT2 is a potential target for antitoxoplasmic intervention design due to its essential role in parasite growth. IMPORTANCE To grow and survive within host cells, Toxoplasma must scavenge necessary nutrients from hosts to support its parasitism. Transporters located in the plasma membrane of the parasites play critical roles in nutrient acquisition. Toxoplasma encodes a large number of transporters, but so far, only a few have been characterized. In this study, we identified two phosphate transporters, TgPiT and TgPT2, to localize to the plasma membrane of Toxoplasma. Although both TgPiT and TgPT2 possess phosphate transport activities, only the novel transporter TgPT2 was essential for parasite growth, both in vitro and in vivo. In addition, TgPT2 and its orthologs are only present in coccidia parasites. As such, TgPT2 represents a potential target for drug design against toxoplasmosis. In addition, our data indicated that Toxoplasma can take up ATP and AMP from the environment, providing new insights into the energy metabolism of Toxoplasma.
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Affiliation(s)
- Jianmin Cui
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
| | - Xuke Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
| | - Jichao Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
| | - Ruilian Jia
- Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, People’s Republic of China
| | - Yaoyu Feng
- Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, People’s Republic of China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
- Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, Hubei Province, People’s Republic of China
- Hubei Hongshan Laboratory, Wuhan, Hubei Province, People’s Republic of China
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5
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PMRT1, a
Plasmodium
-Specific Parasite Plasma Membrane Transporter, Is Essential for Asexual and Sexual Blood Stage Development. mBio 2022; 13:e0062322. [PMID: 35404116 PMCID: PMC9040750 DOI: 10.1128/mbio.00623-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Plasmodium falciparum
-infected erythrocytes possess multiple compartments with designated membranes. Transporter proteins embedded in these membranes not only facilitate movement of nutrients, metabolites, and other molecules between these compartments, but also are common therapeutic targets and can confer antimalarial drug resistance.
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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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Fatoki T, Awofisayo O, Faleye B. Cipargamin could inhibit human adenosine receptor A3 with higher binding affinity than Plasmodium falciparum P-type ATPase 4: An In silico study. ACTA FACULTATIS MEDICAE NAISSENSIS 2022. [DOI: 10.5937/afmnai39-31499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Aim: This study aimed to predict the molecular targets of cipargamin in humans and estimate the structural dynamics and binding affinity of their interactions compared to that of Plasmodium falciparum P-type ATPase 4 (PfATP4). Methods: In silico methods were used in this study which include target prediction, structure modeling and dynamics, and molecular docking. Results: The results showed that cipargamin had 100% probability of binding to the human adenosine A3 receptor (ADORA3) and about 15% for other human targets which include tyrosine-protein kinase JAK2, adenosine A2a receptor, phosphodiesterase 5A and cathepsin K. The results of molecular docking showed that binding energy of cipargamin to PfATP4 and hADORA3 were-12.40 kcal/mol-1 and-13.40 kcal/mol-1 respectively. The docking was validated by the binding of enprofylline and fostamatinib to PfATP4 and hADORA3. Overall, the binding of cipargamin was closely similar to that of fostamatinib. This study shows the potential of cipargamin to modulate the activities of PfATP4 of the parasite (P. falciparum) as well as ADORA3 of the host (Homo sapiens). Conclusion: All the previous studies of cirpagamin have not implicated its action on hADORA3, thus this study provides an insight into a possible role of hADORA3 in the mechanism of malarial infection.
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8
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An Uninvited Seat at the Dinner Table: How Apicomplexan Parasites Scavenge Nutrients from the Host. Microorganisms 2021; 9:microorganisms9122592. [PMID: 34946193 PMCID: PMC8707601 DOI: 10.3390/microorganisms9122592] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 12/24/2022] Open
Abstract
Obligate intracellular parasites have evolved a remarkable assortment of strategies to scavenge nutrients from the host cells they parasitize. Most apicomplexans form a parasitophorous vacuole (PV) within the invaded cell, a replicative niche within which they survive and multiply. As well as providing a physical barrier against host cell defense mechanisms, the PV membrane (PVM) is also an important site of nutrient uptake that is essential for the parasites to sustain their metabolism. This means nutrients in the extracellular milieu are separated from parasite metabolic machinery by three different membranes, the host plasma membrane, the PVM, and the parasite plasma membrane (PPM). In order to facilitate nutrient transport from the extracellular environment into the parasite itself, transporters on the host cell membrane of invaded cells can be modified by secreted and exported parasite proteins to maximize uptake of key substrates to meet their metabolic demand. To overcome the second barrier, the PVM, apicomplexan parasites secrete proteins contained in the dense granules that remodel the vacuole and make the membrane permissive to important nutrients. This bulk flow of host nutrients is followed by a more selective uptake of substrates at the PPM that is operated by specific transporters of this third barrier. In this review, we recapitulate and compare the strategies developed by Apicomplexa to scavenge nutrients from their hosts, with particular emphasis on transporters at the parasite plasma membrane and vacuolar solute transporters on the parasite intracellular digestive organelle.
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9
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Gil JP, Fançony C. Plasmodium falciparum Multidrug Resistance Proteins ( pfMRPs). Front Pharmacol 2021; 12:759422. [PMID: 34790129 PMCID: PMC8591188 DOI: 10.3389/fphar.2021.759422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/05/2021] [Indexed: 12/19/2022] Open
Abstract
The capacity of the lethal Plasmodium falciparum parasite to develop resistance against anti-malarial drugs represents a central challenge in the global control and elimination of malaria. Historically, the action of drug transporters is known to play a pivotal role in the capacity of the parasite to evade drug action. MRPs (Multidrug Resistance Protein) are known in many phylogenetically diverse groups to be related to drug resistance by being able to handle a large range of substrates, including important endogenous substances as glutathione and its conjugates. P. falciparum MRPs are associated with in vivo and in vitro altered drug response, and might be important factors for the development of multi-drug resistance phenotypes, a latent possibility in the present, and future, combination therapy environment. Information on P. falciparum MRPs is scattered in the literature, with no specialized review available. We herein address this issue by reviewing the present state of knowledge.
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Affiliation(s)
- José Pedro Gil
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Faculty of Sciences, BioISI-Biosystems and Integrative Sciences Institute, University of Lisbon, Lisbon, Portugal.,Global Health and Tropical Medicine, Institute of Hygiene and Tropical Medicine, Nova University of Lisbon, Lisbon, Portugal
| | - Cláudia Fançony
- Centro de Investigação em Saúde de Angola (CISA)/Instituto Nacional de Investigação em Saúde (INIS), Caxito, Angola
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10
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Characterization of Apicomplexan Amino Acid Transporters (ApiATs) in the Malaria Parasite Plasmodium falciparum. mSphere 2021; 6:e0074321. [PMID: 34756057 PMCID: PMC8579892 DOI: 10.1128/msphere.00743-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During the symptomatic human blood phase, malaria parasites replicate within red blood cells. Parasite proliferation relies on the uptake of nutrients, such as amino acids, from the host cell and blood plasma, requiring transport across multiple membranes. Amino acids are delivered to the parasite through the parasite-surrounding vacuolar compartment by specialized nutrient-permeable channels of the erythrocyte membrane and the parasitophorous vacuole membrane (PVM). However, further transport of amino acids across the parasite plasma membrane (PPM) is currently not well characterized. In this study, we focused on a family of Apicomplexan amino acid transporters (ApiATs) that comprises five members in Plasmodium falciparum. First, we localized four of the P. falciparum ApiATs (PfApiATs) at the PPM using endogenous green fluorescent protein (GFP) tagging. Next, we applied reverse genetic approaches to probe into their essentiality during asexual replication and gametocytogenesis. Upon inducible knockdown and targeted gene disruption, a reduced asexual parasite proliferation was detected for PfApiAT2 and PfApiAT4. Functional inactivation of individual PfApiATs targeted in this study had no effect on gametocyte development. Our data suggest that individual PfApiATs are partially redundant during asexual in vitro proliferation and fully redundant during gametocytogenesis of P. falciparum parasites. IMPORTANCE Malaria parasites live and multiply inside cells. To facilitate their extremely fast intracellular proliferation, they hijack and transform their host cells. This also requires the active uptake of nutrients, such as amino acids, from the host cell and the surrounding environment through various membranes that are the consequence of the parasite’s intracellular lifestyle. In this paper, we focus on a family of putative amino acid transporters termed ApiAT. We show expression and localization of four transporters in the parasite plasma membrane of Plasmodium falciparum-infected erythrocytes that represent one interface of the pathogen to its host cell. We probed into the impact of functional inactivation of individual transporters on parasite growth in asexual and sexual blood stages of P. falciparum and reveal that only two of them show a modest but significant reduction in parasite proliferation but no impact on gametocytogenesis, pointing toward dispensability within this transporter family.
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11
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Rocamora F, Gupta P, Istvan ES, Luth MR, Carpenter EF, Kümpornsin K, Sasaki E, Calla J, Mittal N, Carolino K, Owen E, Llinás M, Ottilie S, Goldberg DE, Lee MCS, Winzeler EA. PfMFR3: A Multidrug-Resistant Modulator in Plasmodium falciparum. ACS Infect Dis 2021; 7:811-825. [PMID: 33715347 PMCID: PMC8042660 DOI: 10.1021/acsinfecdis.0c00676] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
In
malaria, chemical genetics is a powerful method for assigning
function to uncharacterized genes. MMV085203 and GNF-Pf-3600 are two
structurally related napthoquinone phenotypic screening hits that
kill both blood- and sexual-stage P. falciparum parasites in the low nanomolar to low micromolar range. In order
to understand their mechanism of action, parasites from two different
genetic backgrounds were exposed to sublethal concentrations of MMV085203
and GNF-Pf-3600 until resistance emerged. Whole genome sequencing
revealed all 17 resistant clones acquired nonsynonymous mutations
in the gene encoding the orphan apicomplexan transporter PF3D7_0312500
(pfmfr3) predicted to encode a member of the major
facilitator superfamily (MFS). Disruption of pfmfr3 and testing against a panel of antimalarial compounds showed decreased
sensitivity to MMV085203 and GNF-Pf-3600 as well as other compounds
that have a mitochondrial mechanism of action. In contrast, mutations
in pfmfr3 provided no protection against compounds
that act in the food vacuole or the cytosol. A dihydroorotate dehydrogenase
rescue assay using transgenic parasite lines, however, indicated a
different mechanism of action for both MMV085203 and GNF-Pf-3600 than
the direct inhibition of cytochrome bc1. Green fluorescent protein
(GFP) tagging of PfMFR3 revealed that it localizes to the parasite
mitochondrion. Our data are consistent with PfMFR3 playing roles in
mitochondrial transport as well as drug resistance for clinically
relevant antimalarials that target the mitochondria. Furthermore,
given that pfmfr3 is naturally polymorphic, naturally
occurring mutations may lead to differential sensitivity to clinically
relevant compounds such as atovaquone.
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Affiliation(s)
- Frances Rocamora
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Purva Gupta
- VA San Diego Healthcare System, Medical and Research Sections, La Jolla, California 92161, United States
- Department of Medicine, Division of Pulmonary and Critical Care, University of California, San Diego, La Jolla, California 92037, United States
| | - Eva S. Istvan
- Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63130, United States
| | - Madeline R. Luth
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | | | | | - Erika Sasaki
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Jaeson Calla
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Nimisha Mittal
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Krypton Carolino
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Edward Owen
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Sabine Ottilie
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Daniel E. Goldberg
- Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63130, United States
| | | | - Elizabeth A. Winzeler
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
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12
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Gendrot M, Delandre O, Robert MG, Foguim FT, Benoit N, Amalvict R, Fonta I, Mosnier J, Madamet M, Pradines B. Absence of Association between Methylene Blue Reduced Susceptibility and Polymorphisms in 12 Genes Involved in Antimalarial Drug Resistance in African Plasmodium falciparum. Pharmaceuticals (Basel) 2021; 14:ph14040351. [PMID: 33918981 PMCID: PMC8069138 DOI: 10.3390/ph14040351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/26/2021] [Accepted: 04/07/2021] [Indexed: 11/17/2022] Open
Abstract
Half the human population is exposed to malaria. Plasmodium falciparum antimalarial drug resistance monitoring and development of new drugs are major issues related to the control of malaria. Methylene blue (MB), the oldest synthetic antimalarial, is again a promising drug after the break of its use as an antimalarial drug for more than 80 years and a potential partner for triple combination. Very few data are available on the involvement of polymorphisms on genes known to be associated with standard antimalarial drugs and parasite in vitro susceptibility to MB (cross-resistance). In this context, MB susceptibility was evaluated against 482 isolates of imported malaria from Africa by HRP2-based ELISA chemosusceptibility assay. A total of 12 genes involved in antimalarial drug resistance (Pfcrt, Pfdhfr, Pfmdr1, Pfmdr5, Pfmdr6, PfK13, Pfubq, Pfcarl, Pfugt, Pfact, Pfcoronin, and copy number of Pfpm2) were sequenced by Sanger method and quantitative PCR. On the Pfmdr1 gene, the mutation 86Y combined with 184F led to more susceptible isolates to MB (8.0 nM vs. 11.6 nM, p = 0.03). Concerning Pfmdr6, the isolates bearing 12 Asn repetitions were more susceptible to MB (4.6 nM vs. 11.6 nM, p = 0.005). None of the polymorphisms previously described as involved in antimalarial drug resistance was shown to be associated with reduced susceptibility to MB. Some genes (particularly PfK13, Pfugt, Pfact, Pfpm2) did not present enough genetic variability to draw conclusions about their involvement in reduced susceptibility to MB. None of the polymorphisms analyzed by multiple correspondence analysis (MCA) had an impact on the MB susceptibility of the samples successfully included in the analysis. It seems that there is no in vitro cross-resistance between MB and commonly used antimalarial drugs.
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Affiliation(s)
- Mathieu Gendrot
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
| | - Océane Delandre
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
| | - Marie Gladys Robert
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
| | - Francis Tsombeng Foguim
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
| | - Nicolas Benoit
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
- Centre National de Référence du Paludisme, 13005 Marseille, France
| | - Rémy Amalvict
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
- Centre National de Référence du Paludisme, 13005 Marseille, France
| | - Isabelle Fonta
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
- Centre National de Référence du Paludisme, 13005 Marseille, France
| | - Joel Mosnier
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
- Centre National de Référence du Paludisme, 13005 Marseille, France
| | - Marylin Madamet
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
- Centre National de Référence du Paludisme, 13005 Marseille, France
| | - Bruno Pradines
- Unité Parasitologie et Entomologie, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 13005 Marseille, France; (M.G.); (O.D.); (M.G.R.); (F.T.F.); (N.B.); (R.A.); (I.F.); (J.M.); (M.M.)
- Aix Marseille Univ, IRD, SSA, AP-HM, VITROME, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
- Centre National de Référence du Paludisme, 13005 Marseille, France
- Correspondence:
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13
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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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14
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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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15
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Campagnaro GD, de Koning HP. Purine and pyrimidine transporters of pathogenic protozoa - conduits for therapeutic agents. Med Res Rev 2020; 40:1679-1714. [PMID: 32144812 DOI: 10.1002/med.21667] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/12/2020] [Accepted: 02/18/2020] [Indexed: 02/06/2023]
Abstract
Purines and pyrimidines are essential nutrients for any cell. Most organisms are able to synthesize their own purines and pyrimidines, but this ability was lost in protozoans that adapted to parasitism, leading to a great diversification in transporter activities in these organisms, especially for the acquisition of amino acids and nucleosides from their hosts throughout their life cycles. Many of these transporters have been shown to have sufficiently different substrate affinities from mammalian transporters, making them good carriers for therapeutic agents. In this review, we summarize the knowledge obtained on purine and pyrimidine activities identified in protozoan parasites to date and discuss their importance for the survival of these parasites and as drug carriers, as well as the perspectives of developments in the field.
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Affiliation(s)
- Gustavo D Campagnaro
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 120 University Place, Glasgow, UK
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 120 University Place, Glasgow, UK
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16
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Walzer KA, Fradin H, Emerson LY, Corcoran DL, Chi JT. Latent transcriptional variations of individual Plasmodium falciparum uncovered by single-cell RNA-seq and fluorescence imaging. PLoS Genet 2019; 15:e1008506. [PMID: 31856180 PMCID: PMC6952112 DOI: 10.1371/journal.pgen.1008506] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/09/2020] [Accepted: 11/03/2019] [Indexed: 02/07/2023] Open
Abstract
Malaria parasites follow a complex life cycle that consists of multiple stages that span from the human host to the mosquito vector. Among the species causing malaria, Plasmodium falciparum is the most lethal, with clinical symptoms manifesting during the intraerythrocytic developmental cycle (IDC). During the IDC, P. falciparum progresses through a synchronous and continuous cascade of transcriptional programming previously established using population analyses. While individual parasites are known to exhibit transcriptional variations to evade the host immune system or commit to a sexual fate, such rare expression heterogeneity is largely undetectable on a population level. Therefore, we combined single-cell RNA-sequencing (scRNA-seq) on a microfluidic platform and fluorescence imaging to delineate the transcriptional variations among individual parasites during late asexual and sexual stages. The comparison between asexual and sexual parasites uncovered a set of previously undefined sex-specific genes. Asexual parasites were segregated into three distinct clusters based on the differential expression of genes encoding SERAs, rhoptry proteins, and EXP2 plus transporters. Multiple pseudotime analyses revealed that these stage-specific transitions are distinct. RNA fluorescent in situ hybridization of cluster-specific genes validated distinct stage-specific expression and transitions during the IDC and defined the highly variable transcriptional pattern of EXP2. Additionally, these analyses indicated huge variations in the stage-specific transcript levels among parasites. Overall, scRNA-seq and RNA-FISH of P. falciparum revealed distinct stage transitions and unexpected degrees of heterogeneity with potential impact on transcriptional regulation during the IDC and adaptive responses to the host. Malaria poses a significant global health problem and is responsible for nearly 445,000 deaths. It is caused by a single-celled parasite that infects a human host and propagates asexually through red blood cells. The most deadly malaria parasite, P. falciparum, follows a tightly synchronous life cycle characterized by a continuous cascade of gene expression programming. Beyond these changes in the population, individual P. falciparum parasites are known to exhibit unique and rare expression, particularly to evade the host immune system and also to commit to a sexual fate. But such rare expression is often masked in bulk-cell studies. To understand expression variations among individual parasites, we combined single-cell RNA sequencing and fluorescence imaging to study the gene expression among individual asexual and sexual parasites. We discovered previously undefined sex-specific genes as well as three distinct clusters of late stage asexual parasites largely defined by stage-specific genes. We also showed that EXP2, a marker gene of one cluster, was expressed at multiple times throughout the life cycle. Furthermore, stage-specific gene expression was greatly variable among individual parasites. Our results have great implications for individual parasite survival and adaptation, particularly in response to environmental stresses like the host immune system.
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Affiliation(s)
- Katelyn A. Walzer
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, United States of America
| | - Hélène Fradin
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, United States of America
| | - Liane Y. Emerson
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, United States of America
| | - David L. Corcoran
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, United States of America
| | - Jen-Tsan Chi
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
- Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, United States of America
- * E-mail:
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17
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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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18
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Cowell AN, Winzeler EA. Advances in omics-based methods to identify novel targets for malaria and other parasitic protozoan infections. Genome Med 2019; 11:63. [PMID: 31640748 PMCID: PMC6805675 DOI: 10.1186/s13073-019-0673-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 09/13/2019] [Indexed: 01/23/2023] Open
Abstract
A major advance in antimalarial drug discovery has been the shift towards cell-based phenotypic screening, with notable progress in the screening of compounds against the asexual blood stage, liver stage, and gametocytes. A primary method for drug target deconvolution in Plasmodium falciparum is in vitro evolution of compound-resistant parasites followed by whole-genome scans. Several of the most promising antimalarial drug targets, such as translation elongation factor 2 (eEF2) and phenylalanine tRNA synthetase (PheRS), have been identified or confirmed using this method. One drawback of this method is that if a mutated gene is uncharacterized, a substantial effort may be required to determine whether it is a drug target, a drug resistance gene, or if the mutation is merely a background mutation. Thus, the availability of high-throughput, functional genomic datasets can greatly assist with target deconvolution. Studies mapping genome-wide essentiality in P. falciparum or performing transcriptional profiling of the host and parasite during liver-stage infection with P. berghei have identified potentially druggable pathways. Advances in mapping the epigenomic regulation of the malaria parasite genome have also enabled the identification of key processes involved in parasite development. In addition, the examination of the host genome during infection has identified novel gene candidates associated with susceptibility to severe malaria. Here, we review recent studies that have used omics-based methods to identify novel targets for interventions against protozoan parasites, focusing on malaria, and we highlight the advantages and limitations of the approaches used. These approaches have also been extended to other protozoan pathogens, including Toxoplasma, Trypanosoma, and Leishmania spp., and these studies highlight how drug discovery efforts against these pathogens benefit from the utilization of diverse omics-based methods to identify promising drug targets.
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Affiliation(s)
- Annie N Cowell
- Division of Infectious Diseases and Global Health, Department of Medicine, University of California, San Diego, Gilman Drive, La Jolla, CA, 92093, USA.
| | - Elizabeth A Winzeler
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, Gilman Drive, La Jolla, CA, 92093, USA
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19
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Sosa Y, Deniskin R, Frame IJ, Steiginga MS, Bandyopadhyay D, Graybill TL, Kallal LA, Ouellette MT, Pope AJ, Widdowson KL, Young RJ, Akabas MH. Identification via a Parallel Hit Progression Strategy of Improved Small Molecule Inhibitors of the Malaria Purine Uptake Transporter that Inhibit Plasmodium falciparum Parasite Proliferation. ACS Infect Dis 2019; 5:1738-1753. [PMID: 31373203 DOI: 10.1021/acsinfecdis.9b00168] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Emerging resistance to current antimalarial medicines underscores the importance of identifying new drug targets and novel compounds. Malaria parasites are purine auxotrophic and import purines via the Plasmodium falciparum equilibrative nucleoside transporter type 1 (PfENT1). We previously showed that PfENT1 inhibitors block parasite proliferation in culture. Our goal was to identify additional, possibly more optimal chemical starting points for a drug discovery campaign. We performed a high throughput screen (HTS) of GlaxoSmithKline's 1.8 million compound library with a yeast-based assay to identify PfENT1 inhibitors. We used a parallel progression strategy for hit validation and expansion, with an emphasis on chemical properties in addition to potency. In one arm, the most active hits were tested for human cell toxicity; 201 had minimal toxicity. The second arm, hit expansion, used a scaffold-based substructure search with the HTS hits as templates to identify over 2000 compounds; 123 compounds had activity. Of these 324 compounds, 175 compounds inhibited proliferation of P. falciparum parasite strain 3D7 with IC50 values between 0.8 and ∼180 μM. One hundred forty-two compounds inhibited PfENT1 knockout (pfent1Δ) parasite growth, indicating they also hit secondary targets. Thirty-two hits inhibited growth of 3D7 but not pfent1Δ parasites. Thus, PfENT1 inhibition was sufficient to block parasite proliferation. Therefore, PfENT1 may be a viable target for antimalarial drug development. Six compounds with novel chemical scaffolds were extensively characterized in yeast-, parasite-, and human-erythrocyte-based assays. The inhibitors showed similar potencies against drug sensitive and resistant P. falciparum strains. They represent attractive starting points for development of novel antimalarial drugs.
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Affiliation(s)
| | | | | | - Matthew S. Steiginga
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Deepak Bandyopadhyay
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Todd L. Graybill
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Lorena A. Kallal
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Michael T. Ouellette
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Andrew J. Pope
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Katherine L. Widdowson
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Robert J. Young
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
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20
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Huang R, Zhu H, Shinn P, Ngan D, Ye L, Thakur A, Grewal G, Zhao T, Southall N, Hall MD, Simeonov A, Austin CP. The NCATS Pharmaceutical Collection: a 10-year update. Drug Discov Today 2019; 24:2341-2349. [PMID: 31585169 DOI: 10.1016/j.drudis.2019.09.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/16/2019] [Accepted: 09/24/2019] [Indexed: 12/25/2022]
Abstract
The National Center for Advancing Translational Sciences (NCATS) Pharmaceutical Collection (NPC), a comprehensive collection of clinically approved drugs, was made a public resource in 2011. Over the past decade, the NPC has been systematically profiled for activity across an array of pathways and disease models, generating an unparalleled amount of data. These data have not only enabled the identification of new repurposing candidates with several in clinical trials, but also uncovered new biological insights into drug targets and disease mechanisms. This retrospective provides an update on the NPC in terms of both successes and lessons learned. We also report our efforts in bringing the NPC up-to-date with drugs approved in recent years.
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Affiliation(s)
- Ruili Huang
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA.
| | - Hu Zhu
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Paul Shinn
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Deborah Ngan
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Lin Ye
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Ashish Thakur
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Gurmit Grewal
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Tongan Zhao
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Noel Southall
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Mathew D Hall
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Anton Simeonov
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
| | - Christopher P Austin
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences (NCATS), National Institutes of Health (NIH), Rockville, MD 20850, USA
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21
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Foguim FT, Robert MG, Gueye MW, Gendrot M, Diawara S, Mosnier J, Amalvict R, Benoit N, Bercion R, Fall B, Madamet M, Pradines B. Low polymorphisms in pfact, pfugt and pfcarl genes in African Plasmodium falciparum isolates and absence of association with susceptibility to common anti-malarial drugs. Malar J 2019; 18:293. [PMID: 31455301 PMCID: PMC6712813 DOI: 10.1186/s12936-019-2919-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 08/17/2019] [Indexed: 11/10/2022] Open
Abstract
Background Resistance to all available anti-malarial drugs has emerged and spread including artemisinin derivatives and their partner drugs. Several genes involved in artemisinin and partner drugs resistance, such as pfcrt, pfmdr1, pfK13 or pfpm2, have been identified. However, these genes do not properly explain anti-malarial drug resistance, and more particularly clinical failures observed in Africa. Mutations in genes encoding for Plasmodium falciparum proteins, such as P. falciparum Acetyl-CoA transporter (PfACT), P. falciparum UDP-galactose transporter (PfUGT) and P. falciparum cyclic amine resistance locus (PfCARL) have recently been associated to resistance to imidazolopiperazines and other unrelated drugs. Methods Mutations on pfugt, pfact and pfcarl were characterized on 86 isolates collected in Dakar, Senegal and 173 samples collected from patients hospitalized in France after a travel in African countries from 2015 and 2016 to assess their potential association with ex vivo susceptibility to chloroquine, quinine, lumefantrine, monodesethylamodiaquine, mefloquine, dihydroartemisinin, artesunate, doxycycline, pyronaridine and piperaquine. Results No mutations were found on the genes pfugt and pfact. None of the pfcarl described mutations were identified in these samples from Africa. The K784N mutation was found in one sample and the K734M mutation was identified on 7.9% of all samples for pfcarl. The only significant differences in ex vivo susceptibility according to the K734M mutation were observed for pyronaridine for African isolates from imported malaria and for doxycycline for Senegalese parasites. Conclusion No evidence was found of involvement of these genes in reduced susceptibility to standard anti-malarial drugs in African P. falciparum isolates.
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Affiliation(s)
- Francis Tsombeng Foguim
- Unité Parasitologie et Entomologie, Département de Microbiologie et de maladies infectieuses, Institut de recherche biomédicale des armées, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France.,IRD, SSA, AP-HM, VITROME, Aix Marseille Université, Marseille, France.,IHU Méditerranée Infection, Marseille, France
| | - Marie Gladys Robert
- Unité Parasitologie et Entomologie, Département de Microbiologie et de maladies infectieuses, Institut de recherche biomédicale des armées, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France.,IRD, SSA, AP-HM, VITROME, Aix Marseille Université, Marseille, France.,IHU Méditerranée Infection, Marseille, France
| | | | - Mathieu Gendrot
- Unité Parasitologie et Entomologie, Département de Microbiologie et de maladies infectieuses, Institut de recherche biomédicale des armées, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France.,IRD, SSA, AP-HM, VITROME, Aix Marseille Université, Marseille, France.,IHU Méditerranée Infection, Marseille, France
| | - Silman Diawara
- Fédération des laboratoires, Hôpital Principal de Dakar, Dakar, Senegal
| | - Joel Mosnier
- Unité Parasitologie et Entomologie, Département de Microbiologie et de maladies infectieuses, Institut de recherche biomédicale des armées, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France.,IRD, SSA, AP-HM, VITROME, Aix Marseille Université, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre national de référence du Paludisme, Marseille, France
| | - Rémy Amalvict
- Unité Parasitologie et Entomologie, Département de Microbiologie et de maladies infectieuses, Institut de recherche biomédicale des armées, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France.,IRD, SSA, AP-HM, VITROME, Aix Marseille Université, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre national de référence du Paludisme, Marseille, France
| | - Nicolas Benoit
- Unité Parasitologie et Entomologie, Département de Microbiologie et de maladies infectieuses, Institut de recherche biomédicale des armées, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France.,IRD, SSA, AP-HM, VITROME, Aix Marseille Université, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre national de référence du Paludisme, Marseille, France
| | - Raymond Bercion
- Laboratoire d'analyses médicales, Institut Pasteur de Dakar, Dakar, Senegal
| | - Bécaye Fall
- Fédération des laboratoires, Hôpital Principal de Dakar, Dakar, Senegal
| | - Marylin Madamet
- Unité Parasitologie et Entomologie, Département de Microbiologie et de maladies infectieuses, Institut de recherche biomédicale des armées, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France.,IRD, SSA, AP-HM, VITROME, Aix Marseille Université, Marseille, France.,IHU Méditerranée Infection, Marseille, France.,Centre national de référence du Paludisme, Marseille, France
| | - Bruno Pradines
- Unité Parasitologie et Entomologie, Département de Microbiologie et de maladies infectieuses, Institut de recherche biomédicale des armées, IHU Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France. .,IRD, SSA, AP-HM, VITROME, Aix Marseille Université, Marseille, France. .,IHU Méditerranée Infection, Marseille, France. .,Fédération des laboratoires, Hôpital Principal de Dakar, Dakar, Senegal. .,Centre national de référence du Paludisme, Marseille, France.
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Sexton AE, Doerig C, Creek DJ, Carvalho TG. Post-Genomic Approaches to Understanding Malaria Parasite Biology: Linking Genes to Biological Functions. ACS Infect Dis 2019; 5:1269-1278. [PMID: 31243988 DOI: 10.1021/acsinfecdis.9b00093] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Plasmodium species are evolutionarily distant from model eukaryotes, and as a consequence they exhibit many non-canonical cellular processes. In the post-genomic era, functional "omics" disciplines (transcriptomics, proteomics, and metabolomics) have accelerated our understanding of unique aspects of the biology of malaria parasites. Functional "omics" tools, in combination with genetic manipulations, have offered new opportunities to investigate the function of previously uncharacterized genes. Knowledge of basic parasite biology is fundamental to understanding drug modes of action, mechanisms of drug resistance, and relevance of vaccine candidates. This Perspective highlights recent "omics"-based discoveries in basic biology and gene function of the most virulent human malaria parasite, Plasmodium falciparum.
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Affiliation(s)
- Anna E. Sexton
- Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Christian Doerig
- Centre for Chronic, Inflammatory and Infectious Diseases, Biomedical Sciences Cluster, School of Health and Biomedical Sciences, RMIT University, 264 Plenty Road, Bundoora, VIC 3083, Australia
| | - Darren J. Creek
- Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Teresa G. Carvalho
- Molecular Parasitology Laboratory, Department of Physiology, Anatomy and Microbiology, La Trobe University, Kingsbury Drive, Bundoora, VIC 3086, Australia
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Yadav DK, Kumar S, Teli MK, Yadav R, Chaudhary S. Molecular Targets for Malarial Chemotherapy: A Review. Curr Top Med Chem 2019; 19:861-873. [DOI: 10.2174/1568026619666190603080000] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 02/08/2019] [Accepted: 02/08/2019] [Indexed: 11/22/2022]
Abstract
The malaria parasite resistance to the existing drugs is a serious problem to the currently used
antimalarials and, thus, highlights the urgent need to develop new and effective anti-malarial molecules.
This could be achieved either by the identification of the new drugs for the validated targets or by further
refining/improving the existing antimalarials; or by combining previously effective agents with
new/existing drugs to have a synergistic effect that counters parasite resistance; or by identifying novel
targets for the malarial chemotherapy. In this review article, a comprehensive collection of some of the
novel molecular targets has been enlisted for the antimalarial drugs. The targets which could be deliberated
for developing new anti-malarial drugs could be: membrane biosynthesis, mitochondrial system,
apicoplasts, parasite transporters, shikimate pathway, hematin crystals, parasite proteases, glycolysis,
isoprenoid synthesis, cell cycle control/cycline dependent kinase, redox system, nucleic acid metabolism,
methionine cycle and the polyamines, folate metabolism, the helicases, erythrocyte G-protein, and
farnesyl transferases. Modern genomic tools approaches such as structural biology and combinatorial
chemistry, novel targets could be identified followed by drug development for drug resistant strains providing
wide ranges of novel targets in the development of new therapy. The new approaches and targets
mentioned in the manuscript provide a basis for the development of new unique strategies for antimalarial
therapy with limited off-target effects in the near future.
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Affiliation(s)
- Dharmendra K. Yadav
- College of Pharmacy, Gachon University of Medicine and Science, Hambakmoeiro, 191, Yeonsu-gu, Incheon 406-799, South Korea
| | - Surendra Kumar
- College of Pharmacy, Gachon University of Medicine and Science, Hambakmoeiro, 191, Yeonsu-gu, Incheon 406-799, South Korea
| | - Mahesh K. Teli
- College of Pharmacy, Gachon University of Medicine and Science, Hambakmoeiro, 191, Yeonsu-gu, Incheon 406-799, South Korea
| | - Ravikant Yadav
- Laboratory of Organic and Medicinal Chemistry, Department of Chemistry, Malaviya National Institute of Technology, Jawaharlal Nehru Marg, Jaipur-302017, India
| | - Sandeep Chaudhary
- Laboratory of Organic and Medicinal Chemistry, Department of Chemistry, Malaviya National Institute of Technology, Jawaharlal Nehru Marg, Jaipur-302017, India
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24
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Parker KER, Fairweather SJ, Rajendran E, Blume M, McConville MJ, Bröer S, Kirk K, van Dooren GG. The tyrosine transporter of Toxoplasma gondii is a member of the newly defined apicomplexan amino acid transporter (ApiAT) family. PLoS Pathog 2019; 15:e1007577. [PMID: 30742695 PMCID: PMC6386423 DOI: 10.1371/journal.ppat.1007577] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 02/22/2019] [Accepted: 01/12/2019] [Indexed: 12/20/2022] Open
Abstract
Apicomplexan parasites are auxotrophic for a range of amino acids which must be salvaged from their host cells, either through direct uptake or degradation of host proteins. Here, we describe a family of plasma membrane-localized amino acid transporters, termed the Apicomplexan Amino acid Transporters (ApiATs), that are ubiquitous in apicomplexan parasites. Functional characterization of the ApiATs of Toxoplasma gondii indicate that several of these transporters are important for intracellular growth of the tachyzoite stage of the parasite, which is responsible for acute infections. We demonstrate that the ApiAT protein TgApiAT5-3 is an exchanger for aromatic and large neutral amino acids, with particular importance for L-tyrosine scavenging and amino acid homeostasis, and that TgApiAT5-3 is critical for parasite virulence. Our data indicate that T. gondii expresses additional proteins involved in the uptake of aromatic amino acids, and we present a model for the uptake and homeostasis of these amino acids. Our findings identify a family of amino acid transporters in apicomplexans, and highlight the importance of amino acid scavenging for the biology of this important phylum of intracellular parasites. The Apicomplexa comprise a large number of parasitic protozoa that have obligate intracellular lifestyles and cause significant human and animal diseases, including malaria, cryptosporidiosis, toxoplasmosis, coccidiosis in poultry, and various cattle fevers. Apicomplexans must scavenge essential nutrients from their hosts in order to proliferate and cause disease, including a range of amino acids. The direct uptake of these nutrients is presumed to be mediated by transporter proteins located in the plasma membrane of intracellular stages, although the identities of these proteins are poorly defined. Using a combination of bioinformatic, genetic, cell biological, and physiological approaches, we have characterized an apicomplexan-specific family of plasma membrane-localized transporter proteins that we have called the Apicomplexan Amino acid Transporters (ApiATs). We show that TgApiAT5-3, a member of the family in the apicomplexan Toxoplasma gondii, is an exchanger for aromatic and large neutral amino acids. In particular, it is critical for uptake of tyrosine, and for parasite virulence in a mouse infection model. We conclude that ApiATs are a family of plasma membrane transporters that play crucial roles in amino acid scavenging by apicomplexan parasites.
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Affiliation(s)
- Kathryn E. R. Parker
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | | | - Esther Rajendran
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Martin Blume
- Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, Australia
- Robert Koch Institute, Berlin, Germany
| | - Malcolm J. McConville
- Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC, Australia
| | - Stefan Bröer
- Research School of Biology, Australian National University, Canberra, ACT, Australia
- * E-mail: (GGVD); (KK); (SB)
| | - Kiaran Kirk
- Research School of Biology, Australian National University, Canberra, ACT, Australia
- * E-mail: (GGVD); (KK); (SB)
| | - Giel G. van Dooren
- Research School of Biology, Australian National University, Canberra, ACT, Australia
- * E-mail: (GGVD); (KK); (SB)
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25
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Kumar S, Bhardwaj TR, Prasad DN, Singh RK. Drug targets for resistant malaria: Historic to future perspectives. Biomed Pharmacother 2018; 104:8-27. [PMID: 29758416 DOI: 10.1016/j.biopha.2018.05.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/22/2018] [Accepted: 05/07/2018] [Indexed: 01/05/2023] Open
Abstract
New antimalarial targets are the prime need for the discovery of potent drug candidates. In order to fulfill this objective, antimalarial drug researches are focusing on promising targets in order to develop new drug candidates. Basic metabolism and biochemical process in the malaria parasite, i.e. Plasmodium falciparum can play an indispensable role in the identification of these targets. But, the emergence of resistance to antimalarial drugs is an escalating comprehensive problem with the progress of antimalarial drug development. The development of resistance has highlighted the need for the search of novel antimalarial molecules. The pharmaceutical industries are committed to new drug development due to the global recognition of this life threatening resistance to the currently available antimalarial therapy. The recent developments in the understanding of parasite biology are exhilarating this resistance issue which is further being ignited by malaria genome project. With this background of information, this review was aimed to highlights and provides useful information on various present and promising treatment approaches for resistant malaria, new progresses, pursued by some innovative targets that have been explored till date. This review also discusses modern and futuristic multiple approaches to antimalarial drug discovery and development with pictorial presentations highlighting the various targets, that could be exploited for generating promising new drugs in the future for drug resistant malaria.
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Affiliation(s)
- Sahil Kumar
- School of Pharmacy and Emerging Sciences, Baddi University of Emerging Sciences & Technology, Baddi, Dist. Solan, 173205, Himachal Pradesh, India
| | - T R Bhardwaj
- School of Pharmacy and Emerging Sciences, Baddi University of Emerging Sciences & Technology, Baddi, Dist. Solan, 173205, Himachal Pradesh, India
| | - D N Prasad
- Department of Pharmaceutical Chemistry, Shivalik College of Pharmacy, Nangal, Dist. Rupnagar, 140126, Punjab, India
| | - Rajesh K Singh
- Department of Pharmaceutical Chemistry, Shivalik College of Pharmacy, Nangal, Dist. Rupnagar, 140126, Punjab, India.
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Tindall SM, Vallières C, Lakhani DH, Islahudin F, Ting KN, Avery SV. Heterologous Expression of a Novel Drug Transporter from the Malaria Parasite Alters Resistance to Quinoline Antimalarials. Sci Rep 2018; 8:2464. [PMID: 29410428 PMCID: PMC5802821 DOI: 10.1038/s41598-018-20816-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/22/2018] [Indexed: 12/15/2022] Open
Abstract
Antimalarial drug resistance hampers effective malaria treatment. Critical SNPs in a particular, putative amino acid transporter were recently linked to chloroquine (CQ) resistance in malaria parasites. Here, we show that this conserved protein (PF3D7_0629500 in Plasmodium falciparum; AAT1 in P. chabaudi) is a structural homologue of the yeast amino acid transporter Tat2p, which is known to mediate quinine uptake and toxicity. Heterologous expression of PF3D7_0629500 in yeast produced CQ hypersensitivity, coincident with increased CQ uptake. PF3D7_0629500-expressing cultures were also sensitized to related antimalarials; amodiaquine, mefloquine and particularly quinine. Drug sensitivity was reversed by introducing a SNP linked to CQ resistance in the parasite. Like Tat2p, PF3D7_0629500-dependent quinine hypersensitivity was suppressible with tryptophan, consistent with a common transport mechanism. A four-fold increase in quinine uptake by PF3D7_0629500 expressing cells was abolished by the resistance SNP. The parasite protein localised primarily to the yeast plasma membrane. Its expression varied between cells and this heterogeneity was used to show that high-expressing cell subpopulations were the most drug sensitive. The results reveal that the PF3D7_0629500 protein can determine the level of sensitivity to several major quinine-related antimalarials through an amino acid-inhibitable drug transport function. The potential clinical relevance is discussed.
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Affiliation(s)
- Sarah M Tindall
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Cindy Vallières
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Dev H Lakhani
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Farida Islahudin
- Faculty of Pharmacy, Universiti Kebangsaan, Kuala Lumpur, 50300, Malaysia
| | - Kang-Nee Ting
- Department of Biomedical Sciences, University of Nottingham Malaysia Campus, Semenyih, Malaysia
| | - Simon V Avery
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
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27
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Transmembrane solute transport in the apicomplexan parasite Plasmodium. Emerg Top Life Sci 2017; 1:553-561. [PMID: 33525850 DOI: 10.1042/etls20170097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 11/12/2017] [Accepted: 11/16/2017] [Indexed: 12/22/2022]
Abstract
Apicomplexa are a large group of eukaryotic, single-celled parasites, with complex life cycles that occur within a wide range of different microenvironments. They include important human pathogens such as Plasmodium, the causal agent of malaria, and Toxoplasma, which causes toxoplasmosis most often in immunocompromised individuals. Despite environmental differences in their life cycles, these parasites retain the ability to obtain nutrients, remove waste products, and control ion balances. They achieve this flexibility by relying on proteins that can deliver and remove solutes. This reliance on transport proteins for essential functions makes these pathways excellent potential targets for drug development programmes. Transport proteins are frequently key mediators of drug resistance by their ability to remove drugs from their sites of action. The study of transport processes mediated by integral membrane proteins and, in particular, identification of their physiological functions and localisation, and differentiation from host orthologues has already established new validated drug targets. Our understanding of how apicomplexan parasites have adapted to changing environmental challenges has also increased through the study of their transporters. This brief introduction to membrane transporters of apicomplexans highlights recent discoveries focusing on Plasmodium and emphasises future directions.
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Sayers CP, Mollard V, Buchanan HD, McFadden GI, Goodman CD. A genetic screen in rodent malaria parasites identifies five new apicoplast putative membrane transporters, one of which is essential in human malaria parasites. Cell Microbiol 2017; 20. [DOI: 10.1111/cmi.12789] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 09/04/2017] [Accepted: 09/07/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Claire P. Sayers
- School of BioSciences University of Melbourne Parkville Victoria Australia
| | - Vanessa Mollard
- School of BioSciences University of Melbourne Parkville Victoria Australia
| | - Hayley D. Buchanan
- School of BioSciences University of Melbourne Parkville Victoria Australia
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Schwertz G, Frei MS, Witschel MC, Rottmann M, Leartsakulpanich U, Chitnumsub P, Jaruwat A, Ittarat W, Schäfer A, Aponte RA, Trapp N, Mark K, Chaiyen P, Diederich F. Conformational Aspects in the Design of Inhibitors for Serine Hydroxymethyltransferase (SHMT): Biphenyl, Aryl Sulfonamide, and Aryl Sulfone Motifs. Chemistry 2017; 23:14345-14357. [DOI: 10.1002/chem.201703244] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/15/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Geoffrey Schwertz
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | - Michelle S. Frei
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | | | - Matthias Rottmann
- Swiss Tropical and Public Health Institute (SwissTPHI); Socinstrasse 57 4051 Basel Switzerland
- Universität Basel; Petersplatz 1 4003 Basel Switzerland
| | - Ubolsree Leartsakulpanich
- National Center for Genetic Engineering and Biotechnology; 113 Thailand Science Park, Phahonyothin Road Pathumthani 12120 Thailand
| | - Penchit Chitnumsub
- National Center for Genetic Engineering and Biotechnology; 113 Thailand Science Park, Phahonyothin Road Pathumthani 12120 Thailand
| | - Aritsara Jaruwat
- National Center for Genetic Engineering and Biotechnology; 113 Thailand Science Park, Phahonyothin Road Pathumthani 12120 Thailand
| | - Wanwipa Ittarat
- National Center for Genetic Engineering and Biotechnology; 113 Thailand Science Park, Phahonyothin Road Pathumthani 12120 Thailand
| | - Anja Schäfer
- Swiss Tropical and Public Health Institute (SwissTPHI); Socinstrasse 57 4051 Basel Switzerland
- Universität Basel; Petersplatz 1 4003 Basel Switzerland
| | | | - Nils Trapp
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | - Kerstin Mark
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | - Pimchai Chaiyen
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology; Faculty of Science Mahidol University; 272 Rama VI Road Bangkok 10400 Thailand
- Department of Biomolecular Science and Engineering; School of Biomolecular Science & Engineering; Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley; Rayong 21210 Thailand
| | - François Diederich
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
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Single-cell RNA sequencing reveals a signature of sexual commitment in malaria parasites. Nature 2017; 551:95-99. [PMID: 29094698 DOI: 10.1038/nature24280] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 09/18/2017] [Indexed: 12/16/2022]
Abstract
Pathogens have to balance transmission with persistence. For Plasmodium falciparum, the most widespread and virulent malaria parasite, persistence within its human host requires continuous asexual replication within red blood cells, while its mosquito-borne transmission depends on intra-erythrocytic differentiation into non-replicating sexual stages called gametocytes. Commitment to either fate is determined during the preceding cell cycle that begins with invasion by a single, asexually committed merozoite and ends, 48 hours later, with a schizont releasing newly formed merozoites, all committed to either continued asexual replication or differentiation into gametocytes. Sexual commitment requires the transcriptional activation of ap2-g (PF3D7_1222600), the master regulator of sexual development, from an epigenetically silenced state during asexual replication. AP2-G expression during this 'commitment cycle' prepares gene expression in nascent merozoites to initiate sexual development through a hitherto unknown mechanism. To maintain a persistent infection, the expression of ap2-g is limited to a sub-population of parasites (1-30%, depending on genetic background and growth conditions). As sexually committed schizonts comprise only a sub-population and are morphologically indistinguishable from their asexually committed counterparts, defining their characteristic gene expression has been difficult using traditional, bulk transcriptome profiling. Here we use highly parallel, single-cell RNA sequencing of malaria cultures undergoing sexual commitment to determine the transcriptional changes induced by AP2-G within this sub-population. By analysing more than 18,000 single parasite transcriptomes from a conditional AP2-G knockdown line and NF54 wild-type parasites at multiple stages of development, we show that sexually committed, AP2-G+ mature schizonts specifically upregulate additional regulators of gene expression, including other AP2 transcription factors, histone-modifying enzymes, and regulators of nucleosome positioning. These epigenetic regulators may act to facilitate the expression and/or repression of genes that are necessary for the initiation of gametocyte development in the subsequent cell cycle.
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Bounaadja L, Schmitt M, Albrecht S, Mouray E, Tarnus C, Florent I. Selective inhibition of PfA-M1, over PfA-M17, by an amino-benzosuberone derivative blocks malaria parasites development in vitro and in vivo. Malar J 2017; 16:382. [PMID: 28934959 PMCID: PMC5609037 DOI: 10.1186/s12936-017-2032-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/18/2017] [Indexed: 01/09/2023] Open
Abstract
Background Plasmodium falciparum M1 family aminopeptidase is currently considered as a promising target for anti-malarial chemotherapy. Several series of inhibitors developed by various research groups display IC50/Ki values down to nM range on native PfA-M1 or recombinant forms and block the parasite development in culture at µM to sub-µM concentrations. A handful of these inhibitors has been tested on murine models of malaria and has shown anti plasmodial in vivo activity. However, most of these inhibitors do also target the other neutral malarial aminopeptidase, PfA-M17, often with lower Ki values, which questions the relative involvement and importance of each enzyme in the parasite biology. Results An amino-benzosuberone derivative from a previously published collection of chemicals targeting specifically the M1-aminopeptidases has been identified; it is highly potent on PfA-M1 (Ki = 50 nM) and devoid of inhibitory activity on PfA-M17 (no inhibition up to 100 µM). This amino-benzosuberone derivative (T5) inhibits, in the µM range, the in vitro growth of two P. falciparum strains, 3D7 and FcB1, respectively chloroquino-sensitive and resistant. Evaluated in vivo, on the murine non-lethal model of malaria Plasmodium chabaudi chabaudi, this amino-benzosuberone derivative was able to reduce the parasite burden by 44 and 40% in a typical 4-day Peters assay at a daily dose of 12 and 24 mg/kg by intraperitoneal route of administration. Conclusions The evaluation of a highly selective inhibitor of PfA-M1, over PfA-M17, active on Plasmodium parasites in vitro and in vivo, highlights the relevance of PfA-M1 in the biological development of the parasite as well as in the list of promising anti-malarial targets to be considered in combination with current or future anti-malarial drugs. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-2032-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lotfi Bounaadja
- Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005, Paris, France
| | - Marjorie Schmitt
- Laboratoire de Chimie Moléculaire, CNRS-UMR7509, Université de Strasbourg, 67037, Strasbourg Cedex 2, France
| | - Sébastien Albrecht
- Laboratoire de Chimie Organique et Bioorganique, EA4566, Université de Haute Alsace, 68093, Mulhouse Cedex, France
| | - Elisabeth Mouray
- Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005, Paris, France
| | - Céline Tarnus
- Laboratoire de Chimie Organique et Bioorganique, EA4566, Université de Haute Alsace, 68093, Mulhouse Cedex, France
| | - Isabelle Florent
- Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005, Paris, France.
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Ellekvist P, Mlambo G, Kumar N, Klaerke DA. Functional characterization of malaria parasites deficient in the K + channel Kch2. Biochem Biophys Res Commun 2017; 493:690-696. [PMID: 28864420 DOI: 10.1016/j.bbrc.2017.08.128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 08/28/2017] [Indexed: 11/17/2022]
Abstract
K+ channels are integral membrane proteins, which contribute to maintain vital parameters such as the cellular membrane potential and cell volume. Malaria parasites encode two K+ channel homologues, Kch1 and Kch2, which are well-conserved among members of the Plasmodium genus. In the rodent malaria parasite P. berghei, the functional significance of K+ channel homologue PbKch2 was studied using targeted gene knock-out. The knockout parasites were characterized in a mouse model in terms of growth-kinetics and infectivity in the mosquito vector. Furthermore, using a tracer-uptake technique with 86Rb+ as a K+ congener, the K+ transporting properties of the knockout parasites were assessed. RESULTS Genetic disruption of Kch2 did not grossly affect the phenotype in terms of asexual replication and pathogenicity in a mouse model. In contrast to Kch1-null parasites, Kch2-null parasites were fully capable of forming oocysts in female Anopheles stephensi mosquitoes. 86Rb+ uptake in Kch2-deficient blood-stage P. berghei parasites (Kch2-null) did not differ from that of wild-type (WT) parasites. About two-thirds of the 86Rb+ uptake in WT and in Kch2-null parasites could be inhibited by K+ channel blockers and could be inferred to the presence of functional Kch1 in Kch2 knockout parasites. Kch2 is therefore not required for transport of K+ in P. berghei and is not essential to mosquito-stage sporogonic development of the parasite.
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Affiliation(s)
- Peter Ellekvist
- Medical Department, Herlev & Gentofte Hospital, Copenhagen, Denmark.
| | - Godfree Mlambo
- Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Baltimore, MD, United States
| | - Nirbhay Kumar
- Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Baltimore, MD, United States; Department of Tropical Medicine, Tulane University School of Public Health & Tropical Medicine, New Orleans, LA, United States.
| | - Dan A Klaerke
- Department of Physiology and Biochemistry, IBHV, Faculty of Health & Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
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Gil JP, Krishna S. pfmdr1 (Plasmodium falciparum multidrug drug resistance gene 1): a pivotal factor in malaria resistance to artemisinin combination therapies. Expert Rev Anti Infect Ther 2017; 15:527-543. [DOI: 10.1080/14787210.2017.1313703] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- J. Pedro Gil
- Physiology and Pharmacology Department, Karolinska Institutet, Stockholm, Sweden
| | - S. Krishna
- St George’s University Hospital, Institute for Infection and Immunity, London, United Kingdom
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34
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Rajendran E, Hapuarachchi SV, Miller CM, Fairweather SJ, Cai Y, Smith NC, Cockburn IA, Bröer S, Kirk K, van Dooren GG. Cationic amino acid transporters play key roles in the survival and transmission of apicomplexan parasites. Nat Commun 2017; 8:14455. [PMID: 28205520 PMCID: PMC5316894 DOI: 10.1038/ncomms14455] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 12/30/2016] [Indexed: 11/09/2022] Open
Abstract
Apicomplexans are obligate intracellular parasites that scavenge essential nutrients from their hosts via transporter proteins on their plasma membrane. The identities of the transporters that mediate amino acid uptake into apicomplexans are unknown. Here we demonstrate that members of an apicomplexan-specific protein family-the Novel Putative Transporters (NPTs)-play key roles in the uptake of cationic amino acids. We show that an NPT from Toxoplasma gondii (TgNPT1) is a selective arginine transporter that is essential for parasite survival and virulence. We also demonstrate that a homologue of TgNPT1 from the malaria parasite Plasmodium berghei (PbNPT1), shown previously to be essential for the sexual gametocyte stage of the parasite, is a cationic amino acid transporter. This reveals a role for cationic amino acid scavenging in gametocyte biology. Our study demonstrates a critical role for amino acid transporters in the survival, virulence and life cycle progression of these parasites.
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Affiliation(s)
- Esther Rajendran
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Sanduni V Hapuarachchi
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Catherine M Miller
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, Queensland 4878, Australia
| | - Stephen J Fairweather
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Yeping Cai
- John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Nicholas C Smith
- Queensland Tropical Health Alliance Research Laboratory, Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, Queensland 4878, Australia
| | - Ian A Cockburn
- John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Stefan Bröer
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Kiaran Kirk
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Giel G van Dooren
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
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35
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Labarbuta P, Duckett K, Botting CH, Chahrour O, Malone J, Dalton JP, Law CJ. Recombinant vacuolar iron transporter family homologue PfVIT from human malaria-causing Plasmodium falciparum is a Fe 2+/H +exchanger. Sci Rep 2017; 7:42850. [PMID: 28198449 PMCID: PMC5309874 DOI: 10.1038/srep42850] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 01/18/2017] [Indexed: 02/08/2023] Open
Abstract
Vacuolar iron transporters (VITs) are a poorly understood family of integral membrane proteins that can function in iron homeostasis via sequestration of labile Fe2+ into vacuolar compartments. Here we report on the heterologous overexpression and purification of PfVIT, a vacuolar iron transporter homologue from the human malaria-causing parasite Plasmodium falciparum. Use of synthetic, codon-optimised DNA enabled overexpression of functional PfVIT in the inner membrane of Escherichia coli which, in turn, conferred iron tolerance to the bacterial cells. Cells that expressed PfVIT had decreased levels of total cellular iron compared with cells that did not express the protein. Qualitative transport assays performed on inverted vesicles enriched with PfVIT revealed that the transporter catalysed Fe2+/H+ exchange driven by the proton electrochemical gradient. Furthermore, the PfVIT transport function in this system did not require the presence of any Plasmodium-specific factor such as post-translational phosphorylation. PfVIT purified as a monomer and, as measured by intrinsic protein fluorescence quenching, bound Fe2+ in detergent solution with low micromolar affinity. This study of PfVIT provides material for future detailed biochemical, biophysical and structural studies to advance understanding of the vacuolar iron transporter family of membrane proteins from important human pathogens.
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Affiliation(s)
- Paola Labarbuta
- School of Biological Sciences, Medical Biology Centre, Queen's University Belfast, Belfast BT9 7BL, United Kingdom
| | - Katie Duckett
- School of Biological Sciences, Medical Biology Centre, Queen's University Belfast, Belfast BT9 7BL, United Kingdom
| | - Catherine H Botting
- School of Biology, Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom
| | - Osama Chahrour
- Spectroscopy Group, Analytical Services, Almac, 20 Seagoe Industrial Estate, Craigavon BT63 5QD, United Kingdom
| | - John Malone
- Spectroscopy Group, Analytical Services, Almac, 20 Seagoe Industrial Estate, Craigavon BT63 5QD, United Kingdom
| | - John P Dalton
- School of Biological Sciences, Medical Biology Centre, Queen's University Belfast, Belfast BT9 7BL, United Kingdom
| | - Christopher J Law
- School of Biological Sciences, Medical Biology Centre, Queen's University Belfast, Belfast BT9 7BL, United Kingdom
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36
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Lim MYX, LaMonte G, Lee MC, Reimer C, Tan BH, Corey V, Tjahjadi BF, Chua A, Nachon M, Wintjens R, Gedeck P, Malleret B, Renia L, Bonamy GM, Ho PCL, Yeung BKS, Chow ED, Lim L, Fidock DA, Diagana TT, Winzeler EA, Bifani P. UDP-galactose and acetyl-CoA transporters as Plasmodium multidrug resistance genes. Nat Microbiol 2016; 1:16166. [PMID: 27642791 PMCID: PMC5575994 DOI: 10.1038/nmicrobiol.2016.166] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/08/2016] [Indexed: 01/08/2023]
Abstract
A molecular understanding of drug resistance mechanisms enables surveillance of the effectiveness of new antimicrobial therapies during development and deployment in the field. We used conventional drug resistance selection as well as a regime of limiting dilution at early stages of drug treatment to probe two antimalarial imidazolopiperazines, KAF156 and GNF179. The latter approach permits the isolation of low-fitness mutants that might otherwise be out-competed during selection. Whole-genome sequencing of 24 independently derived resistant Plasmodium falciparum clones revealed four parasites with mutations in the known cyclic amine resistance locus (pfcarl) and a further 20 with mutations in two previously unreported P. falciparum drug resistance genes, an acetyl-CoA transporter (pfact) and a UDP-galactose transporter (pfugt). Mutations were validated both in vitro by CRISPR editing in P. falciparum and in vivo by evolution of resistant Plasmodium berghei mutants. Both PfACT and PfUGT were localized to the endoplasmic reticulum by fluorescence microscopy. As mutations in pfact and pfugt conveyed resistance against additional unrelated chemical scaffolds, these genes are probably involved in broad mechanisms of antimalarial drug resistance.
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Affiliation(s)
- Michelle Yi-Xiu Lim
- Novartis Institute for Tropical Diseases, 138670 Singapore
- Department of Pharmacy, Faculty of Science, National University of Singapore, 119077 Singapore
| | - Gregory LaMonte
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Marcus C.S. Lee
- Department of Microbiology & Immunology, Columbia University Medical Center, New York, New York 10032, USA
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Cambridge CB10 1SA, United Kingdom
| | - Christin Reimer
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Bee Huat Tan
- Novartis Institute for Tropical Diseases, 138670 Singapore
| | - Victoria Corey
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Bianca F. Tjahjadi
- Novartis Institute for Tropical Diseases, 138670 Singapore
- Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System
| | - Adeline Chua
- Novartis Institute for Tropical Diseases, 138670 Singapore
| | - Marie Nachon
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - René Wintjens
- Laboratory of Biopolymers and Supramolecular Nanomaterials, Faculty of Pharmacy, Université Libre de Bruxelles, Brussels, Belgium
| | - Peter Gedeck
- Novartis Institute for Tropical Diseases, 138670 Singapore
| | - Benoit Malleret
- Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System
- Singapore Immunology Network (SIgN), A*Star, Singapore
| | - Laurent Renia
- Singapore Immunology Network (SIgN), A*Star, Singapore
| | | | - Paul Chi-Lui Ho
- Department of Pharmacy, Faculty of Science, National University of Singapore, 119077 Singapore
| | | | - Eric D. Chow
- Center for Advanced Technology, Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143, USA
| | - Liting Lim
- Novartis Institute for Tropical Diseases, 138670 Singapore
| | - David A. Fidock
- Department of Microbiology & Immunology, Columbia University Medical Center, New York, New York 10032, USA
- Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, New York 10032, USA
| | - Thierry T. Diagana
- Novartis Institute for Tropical Diseases, 138670 Singapore
- Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System
| | - Elizabeth A. Winzeler
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Pablo Bifani
- Novartis Institute for Tropical Diseases, 138670 Singapore
- Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System
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37
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Hill DP, D'Eustachio P, Berardini TZ, Mungall CJ, Renedo N, Blake JA. Modeling biochemical pathways in the gene ontology. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2016; 2016:baw126. [PMID: 27589964 PMCID: PMC5009323 DOI: 10.1093/database/baw126] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 08/10/2016] [Indexed: 12/05/2022]
Abstract
The concept of a biological pathway, an ordered sequence of molecular transformations, is used to collect and represent molecular knowledge for a broad span of organismal biology. Representations of biomedical pathways typically are rich but idiosyncratic presentations of organized knowledge about individual pathways. Meanwhile, biomedical ontologies and associated annotation files are powerful tools that organize molecular information in a logically rigorous form to support computational analysis. The Gene Ontology (GO), representing Molecular Functions, Biological Processes and Cellular Components, incorporates many aspects of biological pathways within its ontological representations. Here we present a methodology for extending and refining the classes in the GO for more comprehensive, consistent and integrated representation of pathways, leveraging knowledge embedded in current pathway representations such as those in the Reactome Knowledgebase and MetaCyc. With carbohydrate metabolic pathways as a use case, we discuss how our representation supports the integration of variant pathway classes into a unified ontological structure that can be used for data comparison and analysis.
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Affiliation(s)
- David P Hill
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Peter D'Eustachio
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, USA
| | - Tanya Z Berardini
- Arabidopsis Information Resource, Phoenix Bioinformatics, Redwood City, CA 94063, USA
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38
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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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39
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Pandey K, Ferreira PE, Ishikawa T, Nagai T, Kaneko O, Yahata K. Ca(2+) monitoring in Plasmodium falciparum using the yellow cameleon-Nano biosensor. Sci Rep 2016; 6:23454. [PMID: 27006284 PMCID: PMC4804237 DOI: 10.1038/srep23454] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/07/2016] [Indexed: 11/09/2022] Open
Abstract
Calcium (Ca(2+))-mediated signaling is a conserved mechanism in eukaryotes, including the human malaria parasite, Plasmodium falciparum. Due to its small size (<10 μm) measurement of intracellular Ca(2+) in Plasmodium is technically challenging, and thus Ca(2+) regulation in this human pathogen is not well understood. Here we analyze Ca(2+) homeostasis via a new approach using transgenic P. falciparum expressing the Ca(2+) sensor yellow cameleon (YC)-Nano. We found that cytosolic Ca(2+) concentration is maintained at low levels only during the intraerythrocytic trophozoite stage (30 nM), and is increased in the other blood stages (>300 nM). We determined that the mammalian SERCA inhibitor thapsigargin and antimalarial dihydroartemisinin did not perturb SERCA activity. The change of the cytosolic Ca(2+) level in P. falciparum was additionally detectable by flow cytometry. Thus, we propose that the developed YC-Nano-based system is useful to study Ca(2+) signaling in P. falciparum and is applicable for drug screening.
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Affiliation(s)
- Kishor Pandey
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
- Nepal Academy of Science and Technology (NAST), GPO Box: 3323, Khumaltar, Lalitpur, Nepal
| | - Pedro E. Ferreira
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
- School of Biological Science, Nanyang Technological University, Singapore
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
| | - Takeshi Ishikawa
- Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Takeharu Nagai
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Osamu Kaneko
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Kazuhide Yahata
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
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40
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Rijpma SR, van der Velden M, Bilos A, Jansen RS, Mahakena S, Russel FGM, Sauerwein RW, van de Wetering K, Koenderink JB. MRP1 mediates folate transport and antifolate sensitivity in Plasmodium falciparum. FEBS Lett 2016; 590:482-92. [PMID: 26900081 DOI: 10.1002/1873-3468.12079] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 01/12/2016] [Accepted: 01/18/2016] [Indexed: 11/05/2022]
Abstract
Multidrug resistance-associated proteins (MRP) of Plasmodium falciparum have been associated with altered drug sensitivity. Knowledge on MRP substrate specificity is indispensible for the characterization of resistance mechanisms and identifying its physiological roles. An untargeted metabolomics approach detected decreased folate concentrations in red blood cells infected with schizont stage parasites lacking expression of MRP1. Furthermore, a tenfold decrease in sensitivity toward the folate analog methotrexate was detected for parasites lacking MRP1. PfMRP1 is involved in the export of folate from parasites into red blood cells and is therefore a relevant factor for efficient malaria treatment through the folate pathway.
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Affiliation(s)
- Sanna R Rijpma
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maarten van der Velden
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Albert Bilos
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robert S Jansen
- Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Sunny Mahakena
- Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Frans G M Russel
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Koen van de Wetering
- Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Jan B Koenderink
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
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41
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Functional profiles of orphan membrane transporters in the life cycle of the malaria parasite. Nat Commun 2016; 7:10519. [PMID: 26796412 PMCID: PMC4736113 DOI: 10.1038/ncomms10519] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 12/15/2015] [Indexed: 01/28/2023] Open
Abstract
Assigning function to orphan membrane transport proteins and prioritizing candidates for detailed biochemical characterization remain fundamental challenges and are particularly important for medically relevant pathogens, such as malaria parasites. Here we present a comprehensive genetic analysis of 35 orphan transport proteins of Plasmodium berghei during its life cycle in mice and Anopheles mosquitoes. Six genes, including four candidate aminophospholipid transporters, are refractory to gene deletion, indicative of essential functions. We generate and phenotypically characterize 29 mutant strains with deletions of individual transporter genes. Whereas seven genes appear to be dispensable under the experimental conditions tested, deletion of any of the 22 other genes leads to specific defects in life cycle progression in vivo and/or host transition. Our study provides growing support for a potential link between heavy metal homeostasis and host switching and reveals potential targets for rational design of new intervention strategies against malaria. The functions of many putative membrane transport proteins of malaria parasites are unknown. Here, Kenthirapalan et al. use mutant strains carrying targeted gene deletions to study the functions of 35 such proteins during the life cycle of Plasmodium berghei in mosquito and mouse hosts.
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42
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Cobbold SA, Llinás M, Kirk K. Sequestration and metabolism of host cell arginine by the intraerythrocytic malaria parasite Plasmodium falciparum. Cell Microbiol 2016; 18:820-30. [PMID: 26633083 DOI: 10.1111/cmi.12552] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/14/2015] [Accepted: 11/26/2015] [Indexed: 11/26/2022]
Abstract
Human erythrocytes have an active nitric oxide synthase, which converts arginine into citrulline and nitric oxide (NO). NO serves several important functions, including the maintenance of normal erythrocyte deformability, thereby ensuring efficient passage of the red blood cell through narrow microcapillaries. Here, we show that following invasion by the malaria parasite Plasmodium falciparum the arginine pool in the host erythrocyte compartment is sequestered and metabolized by the parasite. Arginine from the extracellular medium enters the infected cell via endogenous host cell transporters and is taken up by the intracellular parasite by a high-affinity cationic amino acid transporter at the parasite surface. Within the parasite arginine is metabolized into citrulline and ornithine. The uptake and metabolism of arginine by the parasite deprive the erythrocyte of the substrate required for NO production and may contribute to the decreased deformability of infected erythrocytes.
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Affiliation(s)
- Simon A Cobbold
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA.,Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Manuel Llinás
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Kiaran Kirk
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
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Targeting the Plasmodium vivax equilibrative nucleoside transporter 1 (PvENT1) for antimalarial drug development. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2015; 6:1-11. [PMID: 26862473 PMCID: PMC4706624 DOI: 10.1016/j.ijpddr.2015.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/18/2015] [Accepted: 11/25/2015] [Indexed: 11/26/2022]
Abstract
Infection with Plasmodium falciparum and vivax cause most cases of malaria. Emerging resistance to current antimalarial medications makes new drug development imperative. Ideally a new antimalarial drug should treat both falciparum and vivax malaria. Because malaria parasites are purine auxotrophic, they rely on purines imported from the host erythrocyte via Equilibrative Nucleoside Transporters (ENTs). Thus, the purine import transporters represent a potential target for antimalarial drug development. For falciparum parasites the primary purine transporter is the P. falciparum Equilibrative Nucleoside Transporter Type 1 (PfENT1). Recently we identified potent PfENT1 inhibitors with nanomolar IC50 values using a robust, yeast-based high throughput screening assay. In the current work we characterized the Plasmodium vivax ENT1 (PvENT1) homologue and its sensitivity to the PfENT1 inhibitors. We expressed a yeast codon-optimized PvENT1 gene in Saccharomyces cerevisiae. PvENT1-expressing yeast imported both purines ([3H]adenosine) and pyrimidines ([3H]uridine), whereas wild type (fui1Δ) yeast did not. Based on radiolabel substrate uptake inhibition experiments, inosine had the lowest IC50 (3.8 μM), compared to guanosine (14.9 μM) and adenosine (142 μM). For pyrimidines, thymidine had an IC50 of 183 μM (vs. cytidine and uridine; mM range). IC50 values were higher for nucleobases compared to the corresponding nucleosides; hypoxanthine had a 25-fold higher IC50 than inosine. The archetypal human ENT1 inhibitor 4-nitrobenzylthioinosine (NBMPR) had no effect on PvENT1, whereas dipyridamole inhibited PvENT1, albeit with a 40 μM IC50, a 1000-fold less sensitive than human ENT1 (hENT1). The PfENT1 inhibitors blocked transport activity of PvENT1 and the five known naturally occurring non-synonymous single nucleotide polymorphisms (SNPs) with similar IC50 values. Thus, the PfENT1 inhibitors also target PvENT1. This implies that development of novel antimalarial drugs that target both falciparum and vivax ENT1 may be feasible. PvENT1 can be functionally expressed in Saccharomyces cerevisiae. PvENT1 transports purine and pyrimidine nucleosides and nucleobases but does not transport nucleotides. PvENT1 is inhibited by recently described PfENT1 inhibitors with similar potency. Identified PvENT1 non-synonymous SNPs do not change PfENT1 inhibitor potency. Plasmodium ENTs may be feasible target for development of novel antimalarial drugs.
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Key Words
- ACT, Artemisinin-based Combination Therapies
- CQ, chloroquine
- Drug development
- EC50, concentration causing 50% of maximal effect
- ENT, equilibrative nucleoside transporter
- EV, empty vector
- HTS, high throughput screen
- IC50, concentration causing 50% inhibition
- Malaria
- NBMPR, 4-nitrobenzylthioinosine
- Nucleoside/nucleobase transport
- Parasite
- PfENT1, P. falciparum ENT type 1
- Plasmodium vivax
- Purines
- PvENT1, P. vivax ENT type 1
- SDM, synthetic defined media
- SNP, single nucleotide polymorphism
- Single-nucleotide polymorphism (SNP)
- Transporter
- WHO, World Health Organization
- WT, wild type
- hENT1, human ENT type 1
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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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A lactate and formate transporter in the intraerythrocytic malaria parasite, Plasmodium falciparum. Nat Commun 2015; 6:6721. [PMID: 25823844 DOI: 10.1038/ncomms7721] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 02/23/2015] [Indexed: 12/24/2022] Open
Abstract
The intraerythrocytic malaria parasite relies primarily on glycolysis to fuel its rapid growth and reproduction. The major byproduct of this metabolism, lactic acid, is extruded into the external medium. In this study, we show that the human malaria parasite Plasmodium falciparum expresses at its surface a member of the microbial formate-nitrite transporter family (PfFNT), which, when expressed in Xenopus laevis oocytes, transports both formate and lactate. The transport characteristics of PfFNT in oocytes (pH-dependence, inhibitor-sensitivity and kinetics) are similar to those of the transport of lactate and formate across the plasma membrane of mature asexual-stage P. falciparum trophozoites, consistent with PfFNT playing a major role in the efflux of lactate and hence in the energy metabolism of the intraerythrocytic parasite.
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Frame IJ, Deniskin R, Rinderspacher A, Katz F, Deng SX, Moir RD, Adjalley SH, Coburn-Flynn O, Fidock DA, Willis IM, Landry DW, Akabas MH. Yeast-based high-throughput screen identifies Plasmodium falciparum equilibrative nucleoside transporter 1 inhibitors that kill malaria parasites. ACS Chem Biol 2015; 10:775-83. [PMID: 25602169 DOI: 10.1021/cb500981y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Equilibrative transporters are potential drug targets; however, most functional assays involve radioactive substrate uptake that is unsuitable for high-throughput screens (HTS). We developed a robust yeast-based growth assay that is potentially applicable to many equilibrative transporters. As proof of principle, we applied our approach to Equilibrative Nucleoside Transporter 1 of the malarial parasite Plasmodium falciparum (PfENT1). PfENT1 inhibitors might serve as novel antimalarial drugs since PfENT1-mediated purine import is essential for parasite proliferation. To identify PfENT1 inhibitors, we screened 64 560 compounds and identified 171 by their ability to rescue the growth of PfENT1-expressing fui1Δ yeast in the presence of a cytotoxic PfENT1 substrate, 5-fluorouridine (5-FUrd). In secondary assays, nine of the highest activity compounds inhibited PfENT1-dependent growth of a purine auxotrophic yeast strain with adenosine as the sole purine source (IC50 0.2-2 μM). These nine compounds completely blocked [(3)H]adenosine uptake into PfENT1-expressing yeast and erythrocyte-free trophozoite-stage parasites (IC50 5-50 nM), and inhibited chloroquine-sensitive and -resistant parasite proliferation (IC50 5-50 μM). Wild-type (WT) parasite IC50 values were up to 4-fold lower compared to PfENT1-knockout (pfent1Δ) parasites. pfent1Δ parasite killing showed a delayed-death phenotype not observed with WT. We infer that, in parasites, the compounds inhibit both PfENT1 and a secondary target with similar efficacy. The secondary target identity is unknown, but its existence may reduce the likelihood of parasites developing resistance to PfENT1 inhibitors. Our data support the hypothesis that blocking purine transport through PfENT1 may be a novel and compelling approach for antimalarial drug development.
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Affiliation(s)
- I. J. Frame
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Roman Deniskin
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Alison Rinderspacher
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Francine Katz
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Shi-Xian Deng
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Robyn D. Moir
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Sophie H. Adjalley
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Olivia Coburn-Flynn
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - David A. Fidock
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Ian M. Willis
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Donald W. Landry
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
| | - Myles H. Akabas
- Department of Physiology & Biophysics, ‡Department of Biochemistry, §Department of Neuroscience, and ∥Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
- Department of Medicine and #Department of Microbiology & Immunology, Columbia University Medical Center, 630 and 701 West 168th Street, New York, New York 10032, United States
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Baum E, Sattabongkot J, Sirichaisinthop J, Kiattibutr K, Davies DH, Jain A, Lo E, Lee MC, Randall AZ, Molina DM, Liang X, Cui L, Felgner PL, Yan G. Submicroscopic and asymptomatic Plasmodium falciparum and Plasmodium vivax infections are common in western Thailand - molecular and serological evidence. Malar J 2015; 14:95. [PMID: 25849211 PMCID: PMC4342942 DOI: 10.1186/s12936-015-0611-9] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 02/11/2015] [Indexed: 11/21/2022] Open
Abstract
Background Malaria is a public health problem in parts of Thailand, where Plasmodium falciparum and Plasmodium vivax are the main causes of infection. In the northwestern border province of Tak parasite prevalence is now estimated to be less than 1% by microscopy. Nonetheless, microscopy is insensitive at low-level parasitaemia. The objective of this study was to assess the current epidemiology of falciparum and vivax malaria in Tak using molecular methods to detect exposure to and infection with parasites; in particular, the prevalence of asymptomatic infections and infections with submicroscopic parasite levels. Methods Three-hundred microlitres of whole blood from finger-prick were collected into capillary tubes from residents of a sentinel village and from patients at a malaria clinic. Pelleted cellular fractions were screened by quantitative PCR to determine parasite prevalence, while plasma was probed on a protein microarray displaying hundreds of P. falciparum and P. vivax proteins to obtain antibody response profiles in those individuals. Results Of 219 samples from the village, qPCR detected 25 (11.4%) Plasmodium sp. infections, of which 92% were asymptomatic and 100% were submicroscopic. Of 61 samples from the clinic patients, 27 (44.3%) were positive by qPCR, of which 25.9% had submicroscopic parasite levels. Cryptic mixed infections, misdiagnosed as single-species infections by microscopy, were found in 7 (25.9%) malaria patients. All sample donors, parasitaemic and non-parasitaemic alike, had serological evidence of parasite exposure, with 100% seropositivity to at least 54 antigens. Antigens significantly associated with asymptomatic infections were P. falciparum MSP2, DnaJ protein, putative E1E2 ATPase, and three others. Conclusion These findings suggest that parasite prevalence is higher than currently estimated by local authorities based on the standard light microscopy. As transmission levels drop in Thailand, it may be necessary to employ higher throughput and sensitivity methods for parasite detection in the phase of malaria elimination. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0611-9) contains supplementary material, which is available to authorized users.
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Frame IJ, Deniskin R, Arora A, Akabas MH. Purine import into malaria parasites as a target for antimalarial drug development. Ann N Y Acad Sci 2014; 1342:19-28. [PMID: 25424653 DOI: 10.1111/nyas.12568] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Infection with Plasmodium species parasites causes malaria. Plasmodium parasites are purine auxotrophs. In all life cycle stages, they require purines for RNA and DNA synthesis and other cellular metabolic processes. Purines are imported from the host erythrocyte by equilibrative nucleoside transporters (ENTs). They are processed via purine salvage pathway enzymes to form the required purine nucleotides. The Plasmodium falciparum genome encodes four putative ENTs (PfENT1-4). Genetic, biochemical, and physiologic evidence suggest that PfENT1 is the primary purine transporter supplying the purine salvage pathway. Protein mass spectrometry shows that PfENT1 is expressed in all parasite stages. PfENT1 knockout parasites are not viable in culture at purine concentrations found in human blood (<10 μM). Thus, PfENT1 is a potential target for novel antimalarial drugs, but no PfENT1 inhibitors have been identified to test the hypothesis. Identifying inhibitors of PfENT1 is an essential step to validate PfENT1 as a potential antimalarial drug target.
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Affiliation(s)
- I J Frame
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York
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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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Dean P, Major P, Nakjang S, Hirt RP, Embley TM. Transport proteins of parasitic protists and their role in nutrient salvage. FRONTIERS IN PLANT SCIENCE 2014; 5:153. [PMID: 24808897 PMCID: PMC4010794 DOI: 10.3389/fpls.2014.00153] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 04/01/2014] [Indexed: 05/02/2023]
Abstract
The loss of key biosynthetic pathways is a common feature of important parasitic protists, making them heavily dependent on scavenging nutrients from their hosts. This is often mediated by specialized transporter proteins that ensure the nutritional requirements of the parasite are met. Over the past decade, the completion of several parasite genome projects has facilitated the identification of parasite transporter proteins. This has been complemented by functional characterization of individual transporters along with investigations into their importance for parasite survival. In this review, we summarize the current knowledge on transporters from parasitic protists and highlight commonalities and differences in the transporter repertoires of different parasitic species, with particular focus on characterized transporters that act at the host-pathogen interface.
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Affiliation(s)
- Paul Dean
- *Correspondence: Paul Dean and T. Martin Embley, The Medical School, Institute for Cell and Molecular Biosciences, Newcastle University, Catherine Cookson Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK e-mail: ;
| | | | | | | | - T. Martin Embley
- *Correspondence: Paul Dean and T. Martin Embley, The Medical School, Institute for Cell and Molecular Biosciences, Newcastle University, Catherine Cookson Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK e-mail: ;
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