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Alvarez CL, Chêne A, Semblat JP, Gamain B, Lapouméroulie C, Fader CM, Hattab C, Sévigny J, Denis MFL, Lauri N, Ostuni MA, Schwarzbaum PJ. Homeostasis of extracellular ATP in uninfected RBCs from a Plasmodium falciparum culture and derived microparticles. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183980. [PMID: 35654147 DOI: 10.1016/j.bbamem.2022.183980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/11/2022] [Accepted: 05/26/2022] [Indexed: 12/20/2022]
Abstract
Plasmodium falciparum, a dangerous parasitic agent causing malaria, invades human red blood cells (RBCs), causing hemolysis and microvascular obstruction. These and other pathological processes of malaria patients are due to metabolic and structural changes occurring in uninfected RBCs. In addition, infection activates the production of microparticles (MPs). ATP and byproducts are important extracellular ligands modulating purinergic signaling within the intravascular space. Here, we analyzed the contribution of uninfected RBCs and MPs to the regulation of extracellular ATP (eATP) of RBCs, which depends on the balance between ATP release by specific transporters and eATP hydrolysis by ectonucleotidases. RBCs were cultured with P. falciparum for 24-48 h prior to experiments, from which uninfected RBCs and MPs were purified. On-line luminometry was used to quantify the kinetics of ATP release. Luminometry, colorimetry and radioactive methods were used to assess the rate of eATP hydrolysis by ectonucleotidases. Rates of ATP release and eATP hydrolysis were also evaluated in MPs. Uninfected RBCs challenged by different stimuli displayed a strong and transient activation of ATP release, together with an elevated rate of eATP hydrolysis. MPs contained ATP in their lumen, which was released upon vesicle rupture, and were able to hydrolyze eATP. Results suggest that uninfected RBCs and MPs can act as important determinants of eATP regulation of RBCs during malaria. The comparison of eATP homeostasis in infected RBCs, ui-RBCs, and MPs allowed us to speculate on the impact of P. falciparum infection on intravascular purinergic signaling and the control of the vascular caliber by RBCs.
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Affiliation(s)
- Cora L Alvarez
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina; Universidad de Buenos Aires (UBA), Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Intendente Güiraldes 2160, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina
| | - Arnaud Chêne
- Université Paris Cité and Université des Antilles, INSERM, BIGR, F-75015 Paris, France
| | - Jean-Philippe Semblat
- Université Paris Cité and Université des Antilles, INSERM, BIGR, F-75015 Paris, France
| | - Benoît Gamain
- Université Paris Cité and Université des Antilles, INSERM, BIGR, F-75015 Paris, France
| | | | - Claudio M Fader
- Laboratorio de Fisiología y Fisiopatología del Glóbulo Rojo. Instituto de Histología y Embriología (IHEM), Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina; Facultad de Odontología, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claude Hattab
- Université Paris Cité and Université des Antilles, INSERM, BIGR, F-75015 Paris, France
| | - Jean Sévigny
- Centre de Recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - María Florencia Leal Denis
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina; Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Ciencias Químicas, Cátedra de Química Analítica, Junín 956, C1113AAD Buenos Aires, Argentina
| | - Natalia Lauri
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina; Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Ciencias Químicas, Cátedra de Química Analítica, Junín 956, C1113AAD Buenos Aires, Argentina
| | - Mariano A Ostuni
- Université Paris Cité and Université des Antilles, INSERM, BIGR, F-75015 Paris, France
| | - Pablo J Schwarzbaum
- Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini", Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina; Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Ciencias Químicas, Cátedra de Química Analítica, Junín 956, C1113AAD Buenos Aires, Argentina.
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2
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Gabriela M, Matthews KM, Boshoven C, Kouskousis B, Jonsdottir TK, Bullen HE, Modak J, Steer DL, Sleebs BE, Crabb BS, de Koning-Ward TF, Gilson PR. A revised mechanism for how Plasmodium falciparum recruits and exports proteins into its erythrocytic host cell. PLoS Pathog 2022; 18:e1009977. [PMID: 35192672 PMCID: PMC8896661 DOI: 10.1371/journal.ppat.1009977] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 03/04/2022] [Accepted: 02/10/2022] [Indexed: 11/18/2022] Open
Abstract
Plasmodium falciparum exports ~10% of its proteome into its host erythrocyte to modify the host cell's physiology. The Plasmodium export element (PEXEL) motif contained within the N-terminus of most exported proteins directs the trafficking of those proteins into the erythrocyte. To reach the host cell, the PEXEL motif of exported proteins is processed by the endoplasmic reticulum (ER) resident aspartyl protease plasmepsin V. Then, following secretion into the parasite-encasing parasitophorous vacuole, the mature exported protein must be unfolded and translocated across the parasitophorous vacuole membrane by the Plasmodium translocon of exported proteins (PTEX). PTEX is a protein-conducting channel consisting of the pore-forming protein EXP2, the protein unfoldase HSP101, and structural component PTEX150. The mechanism of how exported proteins are specifically trafficked from the parasite's ER following PEXEL cleavage to PTEX complexes on the parasitophorous vacuole membrane is currently not understood. Here, we present evidence that EXP2 and PTEX150 form a stable subcomplex that facilitates HSP101 docking. We also demonstrate that HSP101 localises both within the parasitophorous vacuole and within the parasite's ER throughout the ring and trophozoite stage of the parasite, coinciding with the timeframe of protein export. Interestingly, we found that HSP101 can form specific interactions with model PEXEL proteins in the parasite's ER, irrespective of their PEXEL processing status. Collectively, our data suggest that HSP101 recognises and chaperones PEXEL proteins from the ER to the parasitophorous vacuole and given HSP101's specificity for the EXP2-PTEX150 subcomplex, this provides a mechanism for how exported proteins are specifically targeted to PTEX for translocation into the erythrocyte.
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Affiliation(s)
- Mikha Gabriela
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- School of Medicine, Deakin University, Geelong, Australia
| | - Kathryn M. Matthews
- School of Medicine, Deakin University, Geelong, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, Australia
| | - Cas Boshoven
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Betty Kouskousis
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Thorey K. Jonsdottir
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Hayley E. Bullen
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Joyanta Modak
- School of Medicine, Deakin University, Geelong, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, Australia
| | - David L. Steer
- Monash Biomedical Proteomics and Metabolomics Facility, Monash University, Melbourne, Australia
| | - Brad E. Sleebs
- ACRF Chemical Biology Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Brendan S. Crabb
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
- Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Tania F. de Koning-Ward
- School of Medicine, Deakin University, Geelong, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, Australia
| | - Paul R. Gilson
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
- * E-mail:
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3
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Dumaine JE, Sateriale A, Gibson AR, Reddy AG, Gullicksrud JA, Hunter EN, Clark JT, Striepen B. The enteric pathogen Cryptosporidium parvum exports proteins into the cytosol of the infected host cell. eLife 2021; 10:e70451. [PMID: 34866573 PMCID: PMC8687662 DOI: 10.7554/elife.70451] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 11/19/2021] [Indexed: 12/11/2022] Open
Abstract
The parasite Cryptosporidium is responsible for diarrheal disease in young children causing death, malnutrition, and growth delay. Cryptosporidium invades enterocytes where it develops in a unique intracellular niche. Infected cells exhibit profound changes in morphology, physiology, and transcriptional activity. How the parasite effects these changes is poorly understood. We explored the localization of highly polymorphic proteins and found members of the Cryptosporidium parvum MEDLE protein family to be translocated into the cytosol of infected cells. All intracellular life stages engage in this export, which occurs after completion of invasion. Mutational studies defined an N-terminal host-targeting motif and demonstrated proteolytic processing at a specific leucine residue. Direct expression of MEDLE2 in mammalian cells triggered an ER stress response, which was also observed during infection. Taken together, our studies reveal the presence of a Cryptosporidium secretion system capable of delivering parasite proteins into the infected enterocyte.
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Affiliation(s)
- Jennifer E Dumaine
- Department of Pathobiology, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Adam Sateriale
- Department of Pathobiology, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Alexis R Gibson
- Department of Pathobiology, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Amita G Reddy
- Franklin College of Arts and Science, University of GeorgiaAthensUnited States
| | - Jodi A Gullicksrud
- Department of Pathobiology, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Emma N Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Joseph T Clark
- Department of Pathobiology, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of PennsylvaniaPhiladelphiaUnited States
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4
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de Vries LE, Lunghi M, Krishnan A, Kooij TWA, Soldati-Favre D. Pantothenate and CoA biosynthesis in Apicomplexa and their promise as antiparasitic drug targets. PLoS Pathog 2021; 17:e1010124. [PMID: 34969059 PMCID: PMC8717973 DOI: 10.1371/journal.ppat.1010124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The Apicomplexa phylum comprises thousands of distinct intracellular parasite species, including coccidians, haemosporidians, piroplasms, and cryptosporidia. These parasites are characterized by complex and divergent life cycles occupying a variety of host niches. Consequently, they exhibit distinct adaptations to the differences in nutritional availabilities, either relying on biosynthetic pathways or by salvaging metabolites from their host. Pantothenate (Pan, vitamin B5) is the precursor for the synthesis of an essential cofactor, coenzyme A (CoA), but among the apicomplexans, only the coccidian subgroup has the ability to synthesize Pan. While the pathway to synthesize CoA from Pan is largely conserved across all branches of life, there are differences in the redundancy of enzymes and possible alternative pathways to generate CoA from Pan. Impeding the scavenge of Pan and synthesis of Pan and CoA have been long recognized as potential targets for antimicrobial drug development, but in order to fully exploit these critical pathways, it is important to understand such differences. Recently, a potent class of pantothenamides (PanAms), Pan analogs, which target CoA-utilizing enzymes, has entered antimalarial preclinical development. The potential of PanAms to target multiple downstream pathways make them a promising compound class as broad antiparasitic drugs against other apicomplexans. In this review, we summarize the recent advances in understanding the Pan and CoA biosynthesis pathways, and the suitability of these pathways as drug targets in Apicomplexa, with a particular focus on the cyst-forming coccidian, Toxoplasma gondii, and the haemosporidian, Plasmodium falciparum.
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Affiliation(s)
- Laura E. de Vries
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Matteo Lunghi
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Aarti Krishnan
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Taco W. A. Kooij
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Dominique Soldati-Favre
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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5
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Co-chaperone involvement in knob biogenesis implicates host-derived chaperones in malaria virulence. PLoS Pathog 2021; 17:e1009969. [PMID: 34614006 PMCID: PMC8544838 DOI: 10.1371/journal.ppat.1009969] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 10/25/2021] [Accepted: 09/24/2021] [Indexed: 11/19/2022] Open
Abstract
The pathology associated with malaria infection is largely due to the ability of infected human RBCs to adhere to a number of receptors on endothelial cells within tissues and organs. This phenomenon is driven by the export of parasite-encoded proteins to the host cell, the exact function of many of which is still unknown. Here we inactivate the function of one of these exported proteins, PFA66, a member of the J-domain protein family. Although parasites lacking this protein were still able to grow in cell culture, we observed severe defects in normal host cell modification, including aberrant morphology of surface knobs, disrupted presentation of the cytoadherence molecule PfEMP1, and a total lack of cytoadherence, despite the presence of the knob associated protein KAHRP. Complementation assays demonstrate that an intact J-domain is required for recovery to a wild-type phenotype and suggest that PFA66 functions in concert with a HSP70 to carry out host cell modification. Strikingly, this HSP70 is likely to be of host origin. ATPase assays on recombinant protein verify a functional interaction between PFA66 and residual host cell HSP70. Taken together, our data reveal a role for PFA66 in host cell modification, strongly implicate human HSP70s as being essential in this process and uncover a new KAHRP-independent molecular factor required for correct knob biogenesis. To survive in the human body, the malaria parasite invades and lives within human red blood cells. Once within the red blood cell, the parasite renovates the host cell to its own needs. Here we have studied which factors from both parasite and host cell are required for this renovation process, and discover that human chaperone proteins, referred to as HSP70, are required. It appears that a particular parasite-derived protein, PFA66, recruits and modifies the function of the human HSP70. As this interaction between a parasite and human protein is novel and essential for parasite survival, our study identifies a potential Achilles’ Heel which may be targeted for development of new anti-malaria therapies.
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6
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Jezewski AJ, Lin YH, Reisz JA, Culp-Hill R, Barekatain Y, Yan VC, D'Alessandro A, Muller FL, Odom John AR. Targeting Host Glycolysis as a Strategy for Antimalarial Development. Front Cell Infect Microbiol 2021; 11:730413. [PMID: 34604112 PMCID: PMC8482815 DOI: 10.3389/fcimb.2021.730413] [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: 06/24/2021] [Accepted: 08/17/2021] [Indexed: 11/13/2022] Open
Abstract
Glycolysis controls cellular energy, redox balance, and biosynthesis. Antiglycolytic therapies are under investigation for treatment of obesity, cancer, aging, autoimmunity, and microbial diseases. Interrupting glycolysis is highly valued as a therapeutic strategy, because glycolytic disruption is generally tolerated in mammals. Unfortunately, anemia is a known dose-limiting side effect of these inhibitors and presents a major caveat to development of antiglycolytic therapies. We developed specific inhibitors of enolase – a critical enzyme in glycolysis – and validated their metabolic and cellular effects on human erythrocytes. Enolase inhibition increases erythrocyte susceptibility to oxidative damage and induces rapid and premature erythrocyte senescence, rather than direct hemolysis. We apply our model of red cell toxicity to address questions regarding erythrocyte glycolytic disruption in the context of Plasmodium falciparum malaria pathogenesis. Our study provides a framework for understanding red blood cell homeostasis under normal and disease states and clarifies the importance of erythrocyte reductive capacity in malaria parasite growth.
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Affiliation(s)
- Andrew J Jezewski
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Yu-Hsi Lin
- Department of Cancer Systems Imaging, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Julie A Reisz
- Department of Biochemistry and Molecular Genetics, Aurora, CO, United States
| | - Rachel Culp-Hill
- Department of Biochemistry and Molecular Genetics, Aurora, CO, United States
| | - Yasaman Barekatain
- Department of Cancer Systems Imaging, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Victoria C Yan
- Department of Cancer Systems Imaging, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, Aurora, CO, United States
| | - Florian L Muller
- Department of Cancer Systems Imaging, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, United States.,Department of Neuro-Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Audrey R Odom John
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
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Jonsdottir TK, Gabriela M, Gilson PR. The Role of Malaria Parasite Heat Shock Proteins in Protein Trafficking and Remodelling of Red Blood Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1340:141-167. [PMID: 34569024 DOI: 10.1007/978-3-030-78397-6_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The genus Plasmodium comprises intracellular eukaryotic parasites that infect many vertebrate groups and cause deadly malaria disease in humans. The parasites employ a suite of heat shock proteins to help traffic other proteins to different compartments within their own cells and that of the host cells they parasitise. This review will cover the role of these chaperones in protein export and host cell modification in the asexual blood stage of the human parasite P. falciparum which is the most deadly and well-studied parasite species. We will examine the role chaperones play in the import of proteins into the secretory pathway from where they are escorted to the vacuole space surrounding the intraerythrocytic parasite. Here, other heat shock proteins unfold protein cargoes and extrude them into the red blood cell (RBC) cytosol from where additional chaperones of parasite and possibly host origin refold the cargo proteins and guide them to their final functional destinations within their RBC host cells. The secretory pathway also serves as a launch pad for proteins targeted to the non-photosynthetic apicoplast organelle of endosymbiotic origin, and the role of heat shock proteins in trafficking proteins here will be reviewed. Finally, the function of chaperones in protein trafficking into the mitochondrion, the remaining organelle of endosymbiotic origin, will be discussed.
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Affiliation(s)
- Thorey K Jonsdottir
- Burnet Institute, Melbourne, VIC, Australia.,Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC, Australia
| | - Mikha Gabriela
- Burnet Institute, Melbourne, VIC, Australia.,School of Medicine, Deakin University, Waurn Ponds, VIC, Australia
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8
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Fortuin L, Leshabane M, Pfukwa R, Coertzen D, Birkholtz LM, Klumperman B. Facile Route to Targeted, Biodegradable Polymeric Prodrugs for the Delivery of Combination Therapy for Malaria. ACS Biomater Sci Eng 2020; 6:6217-6227. [DOI: 10.1021/acsbiomaterials.0c01234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lisa Fortuin
- Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag
X1, Matieland 7602, South Africa
| | - Meta Leshabane
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Rueben Pfukwa
- Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag
X1, Matieland 7602, South Africa
| | - Dina Coertzen
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Bert Klumperman
- Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag
X1, Matieland 7602, South Africa
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9
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The parasitophorous vacuole of the blood-stage malaria parasite. Nat Rev Microbiol 2020; 18:379-391. [PMID: 31980807 DOI: 10.1038/s41579-019-0321-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2019] [Indexed: 12/31/2022]
Abstract
The pathology of malaria is caused by infection of red blood cells with unicellular Plasmodium parasites. During blood-stage development, the parasite replicates within a membrane-bound parasitophorous vacuole. A central nexus for host-parasite interactions, this unique parasite shelter functions in nutrient acquisition, subcompartmentalization and the export of virulence factors, making its functional molecules attractive targets for the development of novel intervention strategies to combat the devastating impact of malaria. In this Review, we explore the origin, development, molecular composition and functions of the parasitophorous vacuole of Plasmodium blood stages. We also discuss the relevance of the malaria parasite's intravacuolar lifestyle for successful erythrocyte infection and provide perspectives for future research directions in parasitophorous vacuole biology.
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10
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Krishnan A, Kloehn J, Lunghi M, Soldati-Favre D. Vitamin and cofactor acquisition in apicomplexans: Synthesis versus salvage. J Biol Chem 2020; 295:701-714. [PMID: 31767680 PMCID: PMC6970920 DOI: 10.1074/jbc.aw119.008150] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The Apicomplexa phylum comprises diverse parasitic organisms that have evolved from a free-living ancestor. These obligate intracellular parasites exhibit versatile metabolic capabilities reflecting their capacity to survive and grow in different hosts and varying niches. Determined by nutrient availability, they either use their biosynthesis machineries or largely depend on their host for metabolite acquisition. Because vitamins cannot be synthesized by the mammalian host, the enzymes required for their synthesis in apicomplexan parasites represent a large repertoire of potential therapeutic targets. Here, we review recent advances in metabolic reconstruction and functional studies coupled to metabolomics that unravel the interplay between biosynthesis and salvage of vitamins and cofactors in apicomplexans. A particular emphasis is placed on Toxoplasma gondii, during both its acute and latent stages of infection.
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Affiliation(s)
- Aarti Krishnan
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva CMU, 1 Rue Michel-Servet, 1211 Geneva 4 Switzerland
| | - Joachim Kloehn
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva CMU, 1 Rue Michel-Servet, 1211 Geneva 4 Switzerland
| | - Matteo Lunghi
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva CMU, 1 Rue Michel-Servet, 1211 Geneva 4 Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva CMU, 1 Rue Michel-Servet, 1211 Geneva 4 Switzerland
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11
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Krishnan A, Kloehn J, Lunghi M, Soldati-Favre D. Vitamin and cofactor acquisition in apicomplexans: Synthesis versus salvage. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49928-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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12
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Sharma J, Baumeister S, Przyborski JM, Lingelbach K. Babesia divergens-infected red blood cells take up glutamate via an EAAT3 independent mechanism. Int J Med Microbiol 2017; 308:148-154. [PMID: 29089241 DOI: 10.1016/j.ijmm.2017.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/20/2017] [Accepted: 10/24/2017] [Indexed: 11/28/2022] Open
Abstract
Human red blood cells infected with the malaria parasite Plasmodium falciparum show an increased permeability to a number of solutes. We have previously demonstrated that such infected cells take up glutamate via a member of the excitatory amino acid transporter protein family (EAAT), namely EAAT3. Babesia divergens is a parasite that also infects human erythrocytes, and also induces increased solute permeability, including for glutamate. Here we have investigated whether glutamate uptake in B. divergens infected human red blood cells is also dependent on EAAT3 activity. We find that, although B. divergens infected cells do take up glutamate, this uptake is independent on EAAT3. Thus, though infecting the same host cell, two related parasites have developed distinct pathways to obtain access to nutrients from the extracellular milieu.
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Affiliation(s)
- Jyotsna Sharma
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
| | - Stefan Baumeister
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany.
| | - Jude M Przyborski
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany; Parasitology, Centre for Infectious Diseases, INF324, 69120 Heidelberg, Germany.
| | - Klaus Lingelbach
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
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13
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Carey MA, Papin JA, Guler JL. Novel Plasmodium falciparum metabolic network reconstruction identifies shifts associated with clinical antimalarial resistance. BMC Genomics 2017; 18:543. [PMID: 28724354 PMCID: PMC5518114 DOI: 10.1186/s12864-017-3905-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023] Open
Abstract
Background Malaria remains a major public health burden and resistance has emerged to every antimalarial on the market, including the frontline drug, artemisinin. Our limited understanding of Plasmodium biology hinders the elucidation of resistance mechanisms. In this regard, systems biology approaches can facilitate the integration of existing experimental knowledge and further understanding of these mechanisms. Results Here, we developed a novel genome-scale metabolic network reconstruction, iPfal17, of the asexual blood-stage P. falciparum parasite to expand our understanding of metabolic changes that support resistance. We identified 11 metabolic tasks to evaluate iPfal17 performance. Flux balance analysis and simulation of gene knockouts and enzyme inhibition predict candidate drug targets unique to resistant parasites. Moreover, integration of clinical parasite transcriptomes into the iPfal17 reconstruction reveals patterns associated with antimalarial resistance. These results predict that artemisinin sensitive and resistant parasites differentially utilize scavenging and biosynthetic pathways for multiple essential metabolites, including folate and polyamines. Our findings are consistent with experimental literature, while generating novel hypotheses about artemisinin resistance and parasite biology. We detect evidence that resistant parasites maintain greater metabolic flexibility, perhaps representing an incomplete transition to the metabolic state most appropriate for nutrient-rich blood. Conclusion Using this systems biology approach, we identify metabolic shifts that arise with or in support of the resistant phenotype. This perspective allows us to more productively analyze and interpret clinical expression data for the identification of candidate drug targets for the treatment of resistant parasites. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3905-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maureen A Carey
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, School of Medicine, Charlottesville, USA
| | - Jason A Papin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, USA.
| | - Jennifer L Guler
- Department of Biology, University of Virginia, Charlottesville, USA. .,Division of Infectious Diseases and International Health, University of Virginia, School of Medicine, Charlottesville, USA.
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14
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Tran PN, Brown SHJ, Rug M, Ridgway MC, Mitchell TW, Maier AG. Changes in lipid composition during sexual development of the malaria parasite Plasmodium falciparum. Malar J 2016; 15:73. [PMID: 26852399 PMCID: PMC4744411 DOI: 10.1186/s12936-016-1130-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/23/2016] [Indexed: 01/13/2023] Open
Abstract
Background The development of differentiated sexual stages (gametocytes) within human red blood cells is essential for the propagation of the malaria parasite, since only mature gametocytes will survive in the mosquito’s midgut. Hence gametocytogenesis is a pre-requisite for transmission of the disease. Physiological changes involved in sexual differentiation are still enigmatic. In particular the lipid metabolism—despite being central to cellular regulation and development—is not well explored. Methods Here the lipid profiles of red blood cells infected with the five different sexual stages of Plasmodium falciparum were analysed by mass spectrometry and compared to those from uninfected and asexual trophozoite infected erythrocytes. Results Fundamental differences between erythrocytes infected with the different parasite stages were revealed. In mature gametocytes many lipids that decrease in the trophozoite and early gametocyte infected red blood cells are regained. In particular, regulators of membrane fluidity, cholesterol and sphingomyelin, increased significantly during gametocyte maturation. Neutral lipids (serving mainly as caloriometric reserves) increased from 3 % of total lipids in uninfected to 27 % in stage V gametocyte infected red blood cells. The major membrane lipid class (phospholipids) decreased during gametocyte development. Conclusions The lipid profiles of infected erythrocytes are characteristic for the particular parasite life cycle and maturity stages of gametocytes. The obtained lipid profiles are crucial in revealing the lipid metabolism of malaria parasites and identifying targets to interfere with this deadly disease. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1130-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Phuong N Tran
- Research School of Biology, The Australian National University, Canberra, ACT, Australia. .,La Trobe Institute of Molecular Science, La Trobe University, Melbourne, VIC, Australia.
| | - Simon H J Brown
- School of Medicine and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia.
| | - Melanie Rug
- Research School of Biology, The Australian National University, Canberra, ACT, Australia. .,Centre for Advanced Microscopy, The Australian National University, Canberra, ACT, Australia.
| | - Melanie C Ridgway
- Research School of Biology, The Australian National University, Canberra, ACT, Australia.
| | - Todd W Mitchell
- School of Medicine and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia.
| | - Alexander G Maier
- Research School of Biology, The Australian National University, Canberra, ACT, Australia.
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15
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Jortzik E, Zocher K, Isernhagen A, Mailu BM, Rahlfs S, Viola G, Wittlin S, Hunt NH, Ihmels H, Becker K. Benzo[b]quinolizinium Derivatives Have a Strong Antimalarial Activity and Inhibit Indoleamine Dioxygenase. Antimicrob Agents Chemother 2016; 60:115-25. [PMID: 26459907 PMCID: PMC4704160 DOI: 10.1128/aac.01066-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 10/06/2015] [Indexed: 12/16/2022] Open
Abstract
The heme-containing enzymes indoleamine 2,3-dioxygenase-1 (IDO-1) and IDO-2 catalyze the conversion of the essential amino acid tryptophan into kynurenine. Metabolites of the kynurenine pathway and IDO itself are involved in immunity and the pathology of several diseases, having either immunoregulatory or antimicrobial effects. IDO-1 plays a central role in the pathogenesis of cerebral malaria, which is the most severe and often fatal neurological complication of infection with Plasmodium falciparum. Mouse models are usually used to study the underlying pathophysiology. In this study, we screened a natural compound library against mouse IDO-1 and identified 8-aminobenzo[b]quinolizinium (compound 2c) to be an inhibitor of IDO-1 with potency at nanomolar concentrations (50% inhibitory concentration, 164 nM). Twenty-one structurally modified derivatives of compound 2c were synthesized for structure-activity relationship analyses. The compounds were found to be selective for IDO-1 over IDO-2. We therefore compared the roles of prominent amino acids in the catalytic mechanisms of the two isoenzymes via homology modeling, site-directed mutagenesis, and kinetic analyses. Notably, methionine 385 of IDO-2 was identified to interfere with the entrance of l-tryptophan to the active site of the enzyme, which explains the selectivity of the inhibitors. Most interestingly, several benzo[b]quinolizinium derivatives (6 compounds with 50% effective concentration values between 2.1 and 6.7 nM) were found to be highly effective against P. falciparum 3D7 blood stages in cell culture with a mechanism independent of IDO-1 inhibition. We believe that the class of compounds presented here has unique characteristics; it combines the inhibition of mammalian IDO-1 with strong antiparasitic activity, two features that offer potential for drug development.
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MESH Headings
- Animals
- Antimalarials/chemical synthesis
- Antimalarials/chemistry
- Antimalarials/pharmacology
- Cell Line, Tumor
- Cell Survival/drug effects
- Cloning, Molecular
- Crystallography, X-Ray
- Erythrocytes/drug effects
- Erythrocytes/parasitology
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- Humans
- Indoleamine-Pyrrole 2,3,-Dioxygenase/antagonists & inhibitors
- Indoleamine-Pyrrole 2,3,-Dioxygenase/chemistry
- Indoleamine-Pyrrole 2,3,-Dioxygenase/genetics
- Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism
- Kynurenine/metabolism
- Malaria/drug therapy
- Malaria/parasitology
- Mice
- Mutagenesis, Site-Directed
- Plasmodium berghei/drug effects
- Plasmodium berghei/enzymology
- Plasmodium berghei/genetics
- Plasmodium falciparum/drug effects
- Plasmodium falciparum/enzymology
- Plasmodium falciparum/genetics
- Quinolizines/chemical synthesis
- Quinolizines/chemistry
- Quinolizines/pharmacology
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Structure-Activity Relationship
- Tryptophan/antagonists & inhibitors
- Tryptophan/metabolism
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Affiliation(s)
- Esther Jortzik
- Biochemistry and Molecular Biology, Justus Liebig University, Giessen, Germany
| | - Kathleen Zocher
- Biochemistry and Molecular Biology, Justus Liebig University, Giessen, Germany
| | - Antje Isernhagen
- Biochemistry and Molecular Biology, Justus Liebig University, Giessen, Germany
| | - Boniface M Mailu
- Biochemistry and Molecular Biology, Justus Liebig University, Giessen, Germany
| | - Stefan Rahlfs
- Biochemistry and Molecular Biology, Justus Liebig University, Giessen, Germany
| | - Giampietro Viola
- Department of Woman's and Child's Health, University of Padova, Padua, Italy
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute and University of Basel, Basel, Switzerland
| | - Nicholas H Hunt
- Molecular Immunopathology Unit, University of Sydney, Sydney, NSW, Australia
| | - Heiko Ihmels
- Department of Chemistry and Biology, University of Siegen, Siegen, Germany
| | - Katja Becker
- Biochemistry and Molecular Biology, Justus Liebig University, Giessen, Germany
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16
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Baumeister S, Gangopadhyay P, Repnik U, Lingelbach K. Novel insights into red blood cell physiology using parasites as tools. Eur J Cell Biol 2015; 94:332-9. [DOI: 10.1016/j.ejcb.2015.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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17
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Spillman NJ, Beck JR, Goldberg DE. Protein export into malaria parasite-infected erythrocytes: mechanisms and functional consequences. Annu Rev Biochem 2015; 84:813-41. [PMID: 25621510 DOI: 10.1146/annurev-biochem-060614-034157] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phylum Apicomplexa comprises a large group of obligate intracellular parasites of high medical and veterinary importance. These organisms succeed intracellularly by effecting remarkable changes in a broad range of diverse host cells. The transformation of the host erythrocyte is particularly striking in the case of the malaria parasite Plasmodium falciparum. P. falciparum exports hundreds of proteins that mediate a complex cellular renovation marked by changes in the permeability, rigidity, and cytoadherence properties of the host erythrocyte. The past decade has seen enormous progress in understanding the identity and function of these exported effectors, as well as the mechanisms by which they are trafficked into the host cell. Here we review these advances, place them in the context of host manipulation by related apicomplexans, and propose key directions for future research.
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18
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Alvarez CL, Schachter J, de Sá Pinheiro AA, Silva LDS, Verstraeten SV, Persechini PM, Schwarzbaum PJ. Regulation of extracellular ATP in human erythrocytes infected with Plasmodium falciparum. PLoS One 2014; 9:e96216. [PMID: 24858837 PMCID: PMC4032238 DOI: 10.1371/journal.pone.0096216] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 04/03/2014] [Indexed: 11/18/2022] Open
Abstract
In human erythrocytes (h-RBCs) various stimuli induce increases in [cAMP] that trigger ATP release. The resulting pattern of extracellular ATP accumulation (ATPe kinetics) depends on both ATP release and ATPe degradation by ectoATPase activity. In this study we evaluated ATPe kinetics from primary cultures of h-RBCs infected with P. falciparum at various stages of infection (ring, trophozoite and schizont stages). A "3V" mixture containing isoproterenol (β-adrenergic agonist), forskolin (adenylate kinase activator) and papaverine (phosphodiesterase inhibitor) was used to induce cAMP-dependent ATP release. ATPe kinetics of r-RBCs (ring-infected RBCs), t-RBCs (trophozoite-infected RBCs) and s-RBCs (schizont-infected RBCs) showed [ATPe] to peak acutely to a maximum value followed by a slower time dependent decrease. In all intraerythrocytic stages, values of ΔATP1 (difference between [ATPe] measured 1 min post-stimulus and basal [ATPe]) increased nonlinearly with parasitemia (from 2 to 12.5%). Under 3V exposure, t-RBCs at parasitemia 94% (t94-RBCs) showed 3.8-fold higher ΔATP1 values than in h-RBCs, indicative of upregulated ATP release. Pre-exposure to either 100 µM carbenoxolone, 100 nM mefloquine or 100 µM NPPB reduced ΔATP1 to 83-87% for h-RBCs and 63-74% for t94-RBCs. EctoATPase activity, assayed at both low nM concentrations (300-900 nM) and 500 µM exogenous ATPe concentrations increased approx. 400-fold in t94-RBCs, as compared to h-RBCs, while intracellular ATP concentrations of t94-RBCs were 65% that of h-RBCs. In t94-RBCs, production of nitric oxide (NO) was approx. 7-fold higher than in h-RBCs, and was partially inhibited by L-NAME pre-treatment. In media with L-NAME, ΔATP1 values were 2.7-times higher in h-RBCs and 4.2-times higher in t94-RBCs, than without L-NAME. Results suggest that P. falciparum infection of h-RBCs strongly activates ATP release via Pannexin 1 in these cells. Several processes partially counteracted ATPe accumulation: an upregulated ATPe degradation, an enhanced NO production, and a decreased intracellular ATP concentration.
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Affiliation(s)
- Cora Lilia Alvarez
- Instituto de Química y Fisicoquímica Biológicas (Facultad de Farmacia y Bioquímica), Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal de Rio de Janeiro, Rio de Janeiro, Brasil
- INPeTAm Instituto Nacional de Ciência e Tecnologia em Pesquisa Translacional em Saúde e Ambiente na Reigião Amazônica, Rio de Janeiro, Brasil
| | - Julieta Schachter
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal de Rio de Janeiro, Rio de Janeiro, Brasil
- INPeTAm Instituto Nacional de Ciência e Tecnologia em Pesquisa Translacional em Saúde e Ambiente na Reigião Amazônica, Rio de Janeiro, Brasil
| | - Ana Acacia de Sá Pinheiro
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal de Rio de Janeiro, Rio de Janeiro, Brasil
| | - Leandro de Souza Silva
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal de Rio de Janeiro, Rio de Janeiro, Brasil
| | - Sandra Viviana Verstraeten
- Instituto de Química y Fisicoquímica Biológicas (Facultad de Farmacia y Bioquímica), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Pedro Muanis Persechini
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal de Rio de Janeiro, Rio de Janeiro, Brasil
- INPeTAm Instituto Nacional de Ciência e Tecnologia em Pesquisa Translacional em Saúde e Ambiente na Reigião Amazônica, Rio de Janeiro, Brasil
| | - Pablo Julio Schwarzbaum
- Instituto de Química y Fisicoquímica Biológicas (Facultad de Farmacia y Bioquímica), Universidad de Buenos Aires, Buenos Aires, Argentina
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19
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Nguitragool W, Rayavara K, Desai SA. Proteolysis at a specific extracellular residue implicates integral membrane CLAG3 in malaria parasite nutrient channels. PLoS One 2014; 9:e93759. [PMID: 24699906 PMCID: PMC3974804 DOI: 10.1371/journal.pone.0093759] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 03/09/2014] [Indexed: 11/24/2022] Open
Abstract
The plasmodial surface anion channel mediates uptake of nutrients and other solutes into erythrocytes infected with malaria parasites. The clag3 genes of P. falciparum determine this channel’s activity in human malaria, but how the encoded proteins contribute to transport is unknown. Here, we used proteases to examine the channel’s composition and function. While proteases with distinct specificities all cleaved within an extracellular domain of CLAG3, they produced differing degrees of transport inhibition. Chymotrypsin-induced inhibition depended on parasite genotype, with channels induced by the HB3 parasite affected to a greater extent than those of the Dd2 clone. Inheritance of functional proteolysis in the HB3×Dd2 genetic cross, DNA transfection, and gene silencing experiments all pointed to the clag3 genes, providing independent evidence for a role of these genes. Protease protection assays with a Dd2-specific inhibitor and site-directed mutagenesis revealed that a variant L1115F residue on a CLAG3 extracellular loop contributes to inhibitor binding and accounts for differences in functional proteolysis. These findings indicate that surface-exposed CLAG3 is the relevant pool of this protein for channel function. They also suggest structural models for how exposed CLAG3 domains contribute to pore formation and parasite nutrient uptake.
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Affiliation(s)
- Wang Nguitragool
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail: (WN); (SAD)
| | - Kempaiah Rayavara
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Sanjay A. Desai
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail: (WN); (SAD)
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20
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Mira-Martínez S, Rovira-Graells N, Crowley VM, Altenhofen LM, Llinás M, Cortés A. Epigenetic switches in clag3 genes mediate blasticidin S resistance in malaria parasites. Cell Microbiol 2013; 15:1913-23. [PMID: 23819786 DOI: 10.1111/cmi.12162] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 06/22/2013] [Accepted: 06/27/2013] [Indexed: 02/06/2023]
Abstract
Malaria parasites induce changes in the permeability of the infected erythrocyte membrane to numerous solutes, including toxic compounds. In Plasmodium falciparum, this is mainly mediated by PSAC, a broad-selectivity channel that requires the product of parasite clag3 genes for its activity. The two paralogous clag3 genes, clag3.1 and clag3.2, can be silenced by epigenetic mechanisms and show mutually exclusive expression. Here we show that resistance to the antibiotic blasticidin S (BSD) is associated with switches in the expression of these genes that result in altered solute uptake. Low concentrations of the drug selected parasites that switched from clag3.2 to clag3.1 expression, implying that expression of one or the other clag3 gene confers different transport efficiency to PSAC for some solutes. Selection with higher BSD concentrations resulted in simultaneous silencing of both clag3 genes, which severely compromises PSAC formation as demonstrated by blocked uptake of other PSAC substrates. Changes in the expression of clag3 genes were not accompanied by large genetic rearrangements or mutations at the clag3 loci or elsewhere in the genome. These results demonstrate that malaria parasites can become resistant to toxic compounds such as drugs by epigenetic switches in the expression of genes necessary for the formation of solute channels.
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Affiliation(s)
- Sofía Mira-Martínez
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Catalonia, Spain
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21
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Pérez BC, Teixeira C, Figueiras M, Gut J, Rosenthal PJ, Gomes JRB, Gomes P. Novel cinnamic acid/4-aminoquinoline conjugates bearing non-proteinogenic amino acids: towards the development of potential dual action antimalarials. Eur J Med Chem 2012; 54:887-99. [PMID: 22683112 DOI: 10.1016/j.ejmech.2012.05.022] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 05/11/2012] [Accepted: 05/15/2012] [Indexed: 12/25/2022]
Abstract
A series of cinnamic acid/4-aminoquinoline conjugates conceived to link, through a proper retro-enantio dipeptide, a heterocyclic core known to prevent hemozoin formation, to a trans-cinnamic acid motif capable of inhibiting enzyme catalytic Cys residues, were synthesized as potential dual-action antimalarials. The effect of amino acid configuration and the absence of the dipeptide spacer were also assessed. The replacement of the D-amino acids by their natural L counterparts led to a decrease in both anti-plasmodial and falcipain-inhibitory activity, suggesting that the former are preferable. Molecules with such spacer were active against blood-stage Plasmodium falciparum, in vitro, and hemozoin formation, implying that the dipeptide has a key role in mediating these two activities. In turn, compounds without spacer were better falcipain-2 inhibitors, likely because these compounds are smaller and have their vinyl bonds in closer vicinity to the catalytic Cys, as suggested by molecular modeling calculations. These novel conjugates constitute promising leads for the development of new antiplasmodials targeted at blood-stage malaria parasites.
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Affiliation(s)
- Bianca C Pérez
- Centro de Investigação em Química da Universidade do Porto, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, R. do Campo Alegre, 687, P-4169-007 Porto, Portugal
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22
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Chemical activation of a high-affinity glutamate transporter in human erythrocytes and its implications for malaria-parasite–induced glutamate uptake. Blood 2012; 119:3604-12. [DOI: 10.1182/blood-2011-10-386003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Human erythrocytes have a low basal permeability to L-glutamate and are not known to have a functional glutamate transporter. Here, treatment of human erythrocytes with arsenite was shown to induce the uptake of L-glutamate and D-aspartate, but not that of D-glutamate or L-alanine. The majority of the arsenite-induced L-glutamate influx was via a high-affinity, Na+-dependent system showing characteristics of members of the “excitatory amino acid transporter” (EAAT) family. Western blots and immunofluorescence assays revealed the presence of a member of this family, EAAT3, on the erythrocyte membrane. Erythrocytes infected with the malaria parasite Plasmodium falciparum take up glutamate from the extracellular environment. Although the majority of uptake is via a low-affinity Na+-independent pathway there is, in addition, a high-affinity uptake component, raising the possibility that the parasite activates the host cell glutamate transporter.
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23
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Mbengue A, Yam XY, Braun-Breton C. Human erythrocyte remodelling during Plasmodium falciparum malaria parasite growth and egress. Br J Haematol 2012; 157:171-9. [PMID: 22313394 DOI: 10.1111/j.1365-2141.2012.09044.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The intra-erythrocyte growth and survival of the malarial parasite Plasmodium falciparum is responsible for both uncomplicated and severe malaria cases and depends on the parasite's ability to remodel its host cell. Host cell remodelling has several functions for the parasite, such as acquiring nutrients from the extracellular milieu because of the loss of membrane transporters upon erythrocyte differentiation, avoiding splenic clearance by conferring cytoadhesive properties to the infected erythrocyte, escaping the host immune response by exporting antigenically variant proteins at the red blood cell surface. In addition, parasite-induced changes at the red blood cell membrane and sub-membrane skeleton are also necessary for the efficient release of the parasite progeny from the host cell. Here we review these cellular and molecular changes, which might not only sustain parasite growth but also prepare, at a very early stage, the last step of egress from the host cell.
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Affiliation(s)
- Alassane Mbengue
- CNRS UMR 5235, University Montpellier II, Dynamique des Interactions Membranaires Normales et Pathologiques, Montpellier, France
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24
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Alkhalil A, Hong L, Nguitragool W, Desai SA. Voltage-dependent inactivation of the plasmodial surface anion channel via a cleavable cytoplasmic component. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:367-74. [PMID: 22115742 DOI: 10.1016/j.bbamem.2011.11.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 10/17/2011] [Accepted: 11/08/2011] [Indexed: 01/21/2023]
Abstract
Erythrocytes infected with malaria parasites have increased permeability to ions and various nutrient solutes, mediated by a parasite ion channel known as the plasmodial surface anion channel (PSAC). The parasite clag3 gene family encodes PSAC activity, but there may also be additional unidentified components of this channel. Consistent with a lack of clag3 homology to genes of other ion channels, PSAC has a number of unusual functional properties. Here, we report that PSAC exhibits an unusual form of voltage-dependent inactivation. Inactivation was readily detected in the whole-cell patch-clamp configuration after steps to negative membrane potentials. The fraction of current that inactivates, its kinetics, and the rate of recovery were all voltage-dependent, though with a modest effective valence (0.7±0.1 elementary charges). These properties were not affected by solution composition or charge carrier, suggesting inactivation intrinsic to the channel protein. Intriguingly, inactivation was absent in cell-attached recordings and took several minutes to appear after obtaining the whole-cell configuration, suggesting interactions with soluble cytosolic components. Inactivation could also be largely abolished by application of intracellular, but not extracellular protease. The findings implicate inactivation via a charged cytoplasmic channel domain. This domain may be tethered to one or more soluble intracellular components under physiological conditions.
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25
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Nguitragool W, Bokhari AA, Pillai AD, Rayavara K, Sharma P, Turpin B, Aravind L, Desai SA. Malaria parasite clag3 genes determine channel-mediated nutrient uptake by infected red blood cells. Cell 2011; 145:665-77. [PMID: 21620134 PMCID: PMC3105333 DOI: 10.1016/j.cell.2011.05.002] [Citation(s) in RCA: 192] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Revised: 03/21/2011] [Accepted: 05/02/2011] [Indexed: 12/12/2022]
Abstract
Development of malaria parasites within vertebrate erythrocytes requires nutrient uptake at the host cell membrane. The plasmodial surface anion channel (PSAC) mediates this transport and is an antimalarial target, but its molecular basis is unknown. We report a parasite gene family responsible for PSAC activity. We used high-throughput screening for nutrient uptake inhibitors to identify a compound highly specific for channels from the Dd2 line of the human pathogen P. falciparum. Inheritance of this compound's affinity in a Dd2 × HB3 genetic cross maps to a single parasite locus on chromosome 3. DNA transfection and in vitro selections indicate that PSAC-inhibitor interactions are encoded by two clag3 genes previously assumed to function in cytoadherence. These genes are conserved in plasmodia, exhibit expression switching, and encode an integral protein on the host membrane, as predicted by functional studies. This protein increases host cell permeability to diverse solutes.
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Affiliation(s)
- Wang Nguitragool
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Abdullah A.B. Bokhari
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Ajay D. Pillai
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Kempaiah Rayavara
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Paresh Sharma
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Brad Turpin
- National Instruments, Inc., Austin, TX 78730, USA
| | - L. Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sanjay A. Desai
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
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26
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Baumeister S, Wiesner J, Reichenberg A, Hintz M, Bietz S, Harb OS, Roos DS, Kordes M, Friesen J, Matuschewski K, Lingelbach K, Jomaa H, Seeber F. Fosmidomycin uptake into Plasmodium and Babesia-infected erythrocytes is facilitated by parasite-induced new permeability pathways. PLoS One 2011; 6:e19334. [PMID: 21573242 PMCID: PMC3087763 DOI: 10.1371/journal.pone.0019334] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 03/27/2011] [Indexed: 11/18/2022] Open
Abstract
Background Highly charged compounds typically suffer from low membrane permeability and thus are generally regarded as sub-optimal drug candidates. Nonetheless, the highly charged drug fosmidomycin and its more active methyl-derivative FR900098 have proven parasiticidal activity against erythrocytic stages of the malaria parasite Plasmodium falciparum. Both compounds target the isoprenoid biosynthesis pathway present in bacteria and plastid-bearing organisms, like apicomplexan parasites. Surprisingly, the compounds are inactive against a range of apicomplexans replicating in nucleated cells, including Toxoplasma gondii. Methodology/Principal Findings Since non-infected erythrocytes are impermeable for FR90098, we hypothesized that these drugs are taken up only by erythrocytes infected with Plasmodium. We provide evidence that radiolabeled FR900098 accumulates in theses cells as a consequence of parasite-induced new properties of the host cell, which coincide with an increased permeability of the erythrocyte membrane. Babesia divergens, a related parasite that also infects human erythrocytes and is also known to induce an increase in membrane permeability, displays a similar susceptibility and uptake behavior with regard to the drug. In contrast, Toxoplasma gondii-infected cells do apparently not take up the compounds, and the drugs are inactive against the liver stages of Plasmodium berghei, a mouse malaria parasite. Conclusions/Significance Our findings provide an explanation for the observed differences in activity of fosmidomycin and FR900098 against different Apicomplexa. These results have important implications for future screens aimed at finding new and safe molecular entities active against P. falciparum and related parasites. Our data provide further evidence that parasite-induced new permeability pathways may be exploited as routes for drug delivery.
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Affiliation(s)
- Stefan Baumeister
- Parasitologie, Fachbereich Biologie, Philipps-Universität, Marburg, Germany
| | - Jochen Wiesner
- Institut für Klinische Immunologie und Transfusionsmedizin, Universitätsklinikum Giessen und Marburg GmbH, Giessen, Germany
| | - Armin Reichenberg
- Institut für Klinische Immunologie und Transfusionsmedizin, Universitätsklinikum Giessen und Marburg GmbH, Giessen, Germany
| | - Martin Hintz
- Institut für Klinische Immunologie und Transfusionsmedizin, Universitätsklinikum Giessen und Marburg GmbH, Giessen, Germany
| | - Sven Bietz
- Parasitologie, Fachbereich Biologie, Philipps-Universität, Marburg, Germany
| | - Omar S. Harb
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - David S. Roos
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Maximilian Kordes
- Parasitology Unit, Max-Planck-Institute for Infection Biology, Berlin, Germany
| | - Johannes Friesen
- Parasitology Unit, Max-Planck-Institute for Infection Biology, Berlin, Germany
| | - Kai Matuschewski
- Parasitology Unit, Max-Planck-Institute for Infection Biology, Berlin, Germany
| | - Klaus Lingelbach
- Parasitologie, Fachbereich Biologie, Philipps-Universität, Marburg, Germany
| | - Hassan Jomaa
- Institut für Klinische Immunologie und Transfusionsmedizin, Universitätsklinikum Giessen und Marburg GmbH, Giessen, Germany
| | - Frank Seeber
- Parasitologie, Fachbereich Biologie, Philipps-Universität, Marburg, Germany
- Fachgebiet 16 Parasitologie, Robert-Koch-Institut, Berlin, Germany
- * E-mail:
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27
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Sicard A, Semblat JP, Doerig C, Hamelin R, Moniatte M, Dorin-Semblat D, Spicer JA, Srivastava A, Retzlaff S, Heussler V, Waters AP, Doerig C. Activation of a PAK-MEK signalling pathway in malaria parasite-infected erythrocytes. Cell Microbiol 2011; 13:836-45. [PMID: 21371233 PMCID: PMC3123749 DOI: 10.1111/j.1462-5822.2011.01582.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Merozoites of malaria parasites invade red blood cells (RBCs), where they multiply by schizogony, undergoing development through ring, trophozoite and schizont stages that are responsible for malaria pathogenesis. Here, we report that a protein kinase-mediated signalling pathway involving host RBC PAK1 and MEK1, which do not have orthologues in the Plasmodium kinome, is selectively stimulated in Plasmodium falciparum-infected (versus uninfected) RBCs, as determined by the use of phospho-specific antibodies directed against the activated forms of these enzymes. Pharmacological interference with host MEK and PAK function using highly specific allosteric inhibitors in their known cellular IC50 ranges results in parasite death. Furthermore, MEK inhibitors have parasiticidal effects in vitro on hepatocyte and erythrocyte stages of the rodent malaria parasite Plasmodium berghei, indicating conservation of this subversive strategy in malaria parasites. These findings have profound implications for the development of novel strategies for antimalarial chemotherapy.
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Affiliation(s)
- Audrey Sicard
- INSERM U609/Inserm-EPFL Joint Laboratory,Global Health Institute, Lausanne, Switzerland
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28
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Mitochondrial electron transport inhibition and viability of intraerythrocytic Plasmodium falciparum. Antimicrob Agents Chemother 2010; 54:5281-7. [PMID: 20855748 DOI: 10.1128/aac.00937-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although mitochondrial electron transport is a validated target of the antimalarial drug atovaquone, the molecular details underlying parasite demise are unclear. We have shown that a critical function of mitochondrial electron transport in blood-stage Plasmodium falciparum is to support pyrimidine biosynthesis. Here, we explore the effects of atovaquone, alone and in combination with proguanil, on P. falciparum viability. Our results suggest that the effects of inhibition depend upon the erythrocytic stage of the parasites and the duration of exposure. Ring- and schizont-stage parasites are most resilient to drug treatment and can survive for 48 h, with a fraction remaining viable even after 96 h. Survival of parasites does not appear to require nutrient uptake. Thus, intraerythrocytic parasites with inhibited mitochondrial electron transport and collapsed mitochondrial membrane potential do not undergo apoptosis but enter an apparent static state. These results have significant implications for desirable properties of antimalarials under development that target mitochondrial functions.
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29
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Dhangadamajhi G, Kar SK, Ranjit M. The survival strategies of malaria parasite in the red blood cell and host cell polymorphisms. Malar Res Treat 2010; 2010:973094. [PMID: 22332025 PMCID: PMC3277829 DOI: 10.4061/2010/973094] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 07/07/2010] [Indexed: 11/20/2022] Open
Abstract
Parasite growth within the erythrocyte causes dramatic alterations of host cell which on one hand facilitates nutrients acquisition from extracellular environment and on other hand contributes to the symptoms of severe malaria. The current paper focuses on interactions between the Plasmodium parasite and its metabolically highly reduced host cell, the natural selection of numerous polymorphisms in the genes encoding hemoglobin and other erythrocyte proteins.
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Affiliation(s)
- Gunanidhi Dhangadamajhi
- Regional Medical Research Centre, Indian Council of Medical Research, Chandrasekharpur, Bhubaneswar 751023, India
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30
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Abstract
Members of the phylum Apicomplexa are motile and rapidly dividing intracellular parasites, able to occupy a large spectrum of niches by infecting diverse hosts and invading various cell types. As obligate intracellular parasites, most apicomplexans only survive for a short period extracellularly, and, during this time, have a high energy demand to power gliding motility and invasion into new host cells. Similarly, these fast-replicating intracellular parasites are critically dependent on host-cell nutrients as energy and carbon sources, noticeably for the extensive membrane biogenesis imposed during growth and division. To access host-cell metabolites, the apicomplexans Toxoplasma gondii and Plasmodium falciparum have evolved strategies that exquisitely reflect adaptation to their respective niches. In the present review, we summarize and compare some recent findings regarding the energetic metabolism and carbon sources used by these two genetically tractable apicomplexans during host-cell invasion and intracellular growth and replication.
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31
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Baumeister S, Winterberg M, Przyborski JM, Lingelbach K. The malaria parasite Plasmodium falciparum: cell biological peculiarities and nutritional consequences. PROTOPLASMA 2010; 240:3-12. [PMID: 19949823 DOI: 10.1007/s00709-009-0090-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 11/09/2009] [Indexed: 05/28/2023]
Abstract
Apicomplexan parasites obligatorily invade and multiply within eukaryotic cells. Phylogenetically, they are related to a group of algae which, during their evolution, have acquired a secondary endosymbiont. This organelle, which in the parasite is called the apicoplast, is highly reduced compared to the endosymbionts of algae, but still contains many plant-specific biosynthetic pathways. The malaria parasite Plasmodium falciparum infects mammalian erythrocytes which are devoid of intracellular compartments and which largely lack biosynthetic pathways. Despite the limited resources of nutrition, the parasite grows and generates up to 32 merozoites which are the infectious stages of the complex life cycle. A large part of the intra-erythrocytic development takes place in the so-called parasitophorous vacuole, a compartment which forms an interface between the parasite and the cytoplasm of the host cell. In the course of parasite growth, the host cell undergoes dramatic alterations which on one hand contribute directly to the symptoms of severe malaria and which, on the other hand, are also required for parasite survival. Some of these alterations facilitate the acquisition of nutrients from the extracellular environment which are not provided by the host cell. Here, we describe the cell biologically unique interactions between an intracellular eukaryotic pathogen and its metabolically highly reduced host cell. We further discuss current models to explain the appearance of pathogen-induced novel physiological properties in a host cell which has lost its genetic programme.
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Affiliation(s)
- Stefan Baumeister
- Department of Parasitology, Faculty of Biology, Philipps Universität, Marburg, Germany
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32
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Abstract
Most Apicomplexans possess a relic plastid named apicoplast, originating from secondary endosymbiosis of a red algae. This non-photosynthetic organelle fulfils important metabolic functions and confers sensitivity to antibiotics. The tasks of this organelle is compared across the phylum of Apicomplexa, highlighting its role in metabolic adaptation to different intracellular niches.
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33
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Abstract
The malaria parasite-infected erythrocyte is a multi-compartment structure, incorporating numerous different membrane systems. The movement of nutrients, metabolites and inorganic ions into and out of the intraerythrocytic parasite, as well as between subcellular compartments within the parasite, is mediated by transporters and channels - integral membrane proteins that facilitate the movement of solutes across the membrane bilayer. Proteins of this type also play a key role in antimalarial drug resistance. Genes encoding transporters and channels account for at least 2.5% of the parasite genome. However, ascribing functions and physiological roles to these proteins, and defining their roles in drug resistance, is not straightforward. For any given membrane transport protein, a full understanding of its role(s) in the parasitized erythrocyte requires a knowledge of its subcellular localization and substrate specificity, as well as some knowledge of the effects on the parasite of modifying the sequence and/or level of expression of the gene involved. Here we consider recent work in this area, describe a number of newly identified transport proteins, and summarize the likely subcellular localization and putative substrate specificity of all of the candidate membrane transport proteins identified to date.
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Affiliation(s)
- Rowena E Martin
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia.
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34
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Alkhalil A, Pillai AD, Bokhari AAB, Vaidya AB, Desai SA. Complex inheritance of the plasmodial surface anion channel in a Plasmodium falciparum genetic cross. Mol Microbiol 2009; 72:459-69. [PMID: 19320831 DOI: 10.1111/j.1365-2958.2009.06661.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Human erythrocytes infected with the malaria parasite Plasmodium falciparum have increased permeabilities to many solutes. The plasmodial surface anion channel (PSAC) may mediate these changes. Despite good understanding of the biochemical and biophysical properties, the genetic basis of PSAC activity remains unknown. Functional polymorphisms in laboratory isolates and two mutants generated by in vitro selection implicate a parasite-encoded channel, although parasite-induced modifications of endogenous channels have not been formally excluded. Here, we identified stable differences in furosemide efficacy against PSAC activity induced by HB3 and 3D7A parasites. This difference was apparent in both single PSAC patch-clamp recordings and in sorbitol-mediated osmotic lysis measurements, confirming that Cl(-) and sorbitol are transported by a single-channel type. Examination of 19 progeny from a genetic cross between HB3 and 3D7A revealed complex inheritance with some cloned progeny exhibiting furosemide affinities outside the range of parental values. Isolates generated by selfing of the 3D7A clone also exhibited altered furosemide affinities, implicating changes in one or more alleles during meiosis or passage through a primate host. PSAC may be encoded by multiple parasite genes (e.g. a multi-gene family or multiple genes that encode distinct channel subunits) or a single polymorphic gene under strong selective pressure.
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Affiliation(s)
- Abdulnaser Alkhalil
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
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35
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Merckx A, Bouyer G, Thomas SLY, Langsley G, Egée S. Anion channels in Plasmodium-falciparum-infected erythrocytes and protein kinase A. Trends Parasitol 2009; 25:139-44. [PMID: 19200784 DOI: 10.1016/j.pt.2008.12.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 12/01/2008] [Accepted: 12/10/2008] [Indexed: 01/09/2023]
Abstract
By replicating within red blood cells, malaria parasites are largely hidden from immune recognition; however, in the cells, nutrients are limiting and hazardous metabolic end products can rapidly accumulate. Therefore, to survive within erythrocytes, parasites alter the permeability of the host plasma membrane, either by upregulating existing transporters or by creating new permeation pathways. Recent electrophysiological studies of Plasmodium-infected erythrocytes have demonstrated that membrane permeability is mediated by transmembrane transport through ion channels in the infected erythrocyte. This article discusses the evidence and controversies concerning the nature of these channels and surveys the potential role of phosphorylation in activating anion channels that could be important in developing novel strategies for future malarial chemotherapies.
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Affiliation(s)
- Anaïs Merckx
- Institut Cochin, INSERM U567, Université Paris Descartes, CNRS (UMR 8104), Paris, France
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36
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Gehde N, Hinrichs C, Montilla I, Charpian S, Lingelbach K, Przyborski JM. Protein unfolding is an essential requirement for transport across the parasitophorous vacuolar membrane ofPlasmodium falciparum. Mol Microbiol 2009; 71:613-28. [DOI: 10.1111/j.1365-2958.2008.06552.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Boddey JA, Moritz RL, Simpson RJ, Cowman AF. Role of the Plasmodium export element in trafficking parasite proteins to the infected erythrocyte. Traffic 2008; 10:285-99. [PMID: 19055692 PMCID: PMC2682620 DOI: 10.1111/j.1600-0854.2008.00864.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The intracellular survival of Plasmodium falciparum within human erythrocytes is dependent on export of parasite proteins that remodel the host cell. Most exported proteins require a conserved motif (RxLxE/Q/D), termed the Plasmodium export element (PEXEL) or vacuolar targeting sequence (VTS), for targeting beyond the parasitophorous vacuole membrane and into the host cell; however, the precise role of this motif in export is poorly defined. We used transgenic P. falciparum expressing chimeric proteins to investigate the function of the PEXEL motif for export. The PEXEL constitutes a bifunctional export motif comprising a protease recognition sequence that is cleaved, in the endoplasmic reticulum, from proteins destined for export, in a PEXEL arginine- and leucine-dependent manner. Following processing, the remaining conserved PEXEL residue is required to direct the mature protein to the host cell. Furthermore, we demonstrate that N acetylation of proteins following N-terminal processing is a PEXEL-independent process that is insufficient for correct export to the host cell. This work defines the role of each residue in the PEXEL for export into the P. falciparum-infected erythrocyte.
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Affiliation(s)
- Justin A Boddey
- The Walter and Eliza Hall Institute of Medical Research, Parkville 3050, Melbourne, Australia
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38
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Abstract
The phylum Apicomplexa consists of a diverse group of obligate, intracellular parasites. The distinct evolutionary pressures on these protozoans as they have adapted to their respective niches have resulted in a variety of methods that they use to interact with and modify their hosts. One of these is the secretion and trafficking of parasite proteins into the host cell. We review this process for Theileria, Toxoplasma and Plasmodium. We also present what is known about the mechanisms by which parasite proteins are exported into the host cell, as well as information on their known and putative functions once they have reached their final destination.
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Affiliation(s)
- Sandeep Ravindran
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5124, USA
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39
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Sherman IW. References. ADVANCES IN PARASITOLOGY 2008. [DOI: 10.1016/s0065-308x(08)00430-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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40
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Azim-Zadeh O, Hillebrecht A, Linne U, Marahiel MA, Klebe G, Lingelbach K, Nyalwidhe J. Use of biotin derivatives to probe conformational changes in proteins. J Biol Chem 2007; 282:21609-17. [PMID: 17545162 DOI: 10.1074/jbc.m610921200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sulfosuccinimidyl-6-(biotinamido) hexanoate and derivatives thereof covalently bind to the epsilon-amino group of lysine residues. Our observation that access of the biotin derivative to specific lysine residues depends on conformational properties of the entire polypeptide chain prompted us to investigate whether differential biotinylation patterns of a protein can be used as indicators for conformational changes. Bovine serum albumin is a soluble protein with characteristic unfolding kinetics upon exposure to high temperature. First, we show that biotinylation patterns of proteins are highly reproducible. Second, we demonstrate by mass spectrometry and tandem mass spectrometry that unfolding of the protein correlates with the accessibility of the biotin derivative to specific lysine residues. We have applied this experimental strategy to the analysis of a cell-surface protein, viz. the human band 3 anion exchanger of erythrocytes infected with the malaria parasite Plasmodium falciparum. We found that Lys(826) in a highly flexible loop can be biotinylated in non-infected (but not infected) erythrocytes, confirming earlier observations (Winograd, E., and Sherman, I. W. (2004) Mol. Biochem. Parasitol. 138, 83-87) based on epitope-specific monoclonal antibodies suggesting that this region undergoes a conformational change upon infection.
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Affiliation(s)
- Omid Azim-Zadeh
- Fachbereich Biologie, Philipps-Universität Marburg, Marburg, Germany
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41
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Hill DA, Pillai AD, Nawaz F, Hayton K, Doan L, Lisk G, Desai SA. A blasticidin S-resistant Plasmodium falciparum mutant with a defective plasmodial surface anion channel. Proc Natl Acad Sci U S A 2007; 104:1063-8. [PMID: 17213308 PMCID: PMC1783364 DOI: 10.1073/pnas.0610353104] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Erythrocytes infected with malaria parasites exhibit marked increases in permeability to organic and inorganic solutes. The plasmodial surface anion channel (PSAC), an unusual voltage-dependent ion channel induced on the host membrane after infection, may play a central role in these permeability changes. Here, we identified a functional PSAC mutant through in vitro selection with blasticidin S. Resistance to blasticidin S was generated during culture and correlated with significant reductions in permeability to multiple solutes, consistent with uptake via a common pathway. Single channel recordings revealed marked changes in PSAC gating with the addition of a subconductance state not present in wild-type channels. The channel's selectivity profile and pharmacology also were significantly altered. Eventual loss of the mutant phenotype upon removal of selective pressure and slower growth of mutant parasites suggest that PSAC serves an important role in intracellular parasite survival. These findings provide solid evidence for the uptake of diverse solutes via PSAC and implicate one or more parasite genes in expression of this channel.
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Affiliation(s)
- David A. Hill
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852
| | - Ajay D. Pillai
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852
| | - Fatima Nawaz
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852
| | - Karen Hayton
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852
| | - Lanxuan Doan
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852
| | - Godfrey Lisk
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852
| | - Sanjay A. Desai
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852
- *To whom correspondence should be addressed. E-mail:
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42
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Staines HM, Alkhalil A, Allen RJ, De Jonge HR, Derbyshire E, Egée S, Ginsburg H, Hill DA, Huber SM, Kirk K, Lang F, Lisk G, Oteng E, Pillai AD, Rayavara K, Rouhani S, Saliba KJ, Shen C, Solomon T, Thomas SLY, Verloo P, Desai SA. Electrophysiological studies of malaria parasite-infected erythrocytes: current status. Int J Parasitol 2007; 37:475-82. [PMID: 17292372 PMCID: PMC2746352 DOI: 10.1016/j.ijpara.2006.12.013] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Revised: 12/21/2006] [Accepted: 12/21/2006] [Indexed: 11/28/2022]
Abstract
The altered permeability characteristics of erythrocytes infected with malaria parasites have been a source of interest for over 30 years. Recent electrophysiological studies have provided strong evidence that these changes reflect transmembrane transport through ion channels in the host erythrocyte plasma membrane. However, conflicting results and differing interpretations of the data have led to confusion in this field. In an effort to unravel these issues, the groups involved recently came together for a week of discussion and experimentation. In this article, the various models for altered transport are reviewed, together with the areas of consensus in the field and those that require a better understanding.
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Affiliation(s)
- Henry M Staines
- Centre for Infection, Division of Cellular and Molecular Medicine, St. George's, University of London, London SW17 0RE, UK.
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