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Musasia FK, Nkumama IN, Frank R, Kipkemboi V, Schneider M, Mwai K, Odera DO, Rosenkranz M, Fürle K, Kimani D, Tuju J, Njuguna P, Hamaluba M, Kapulu MC, Wardemann H, Osier FHA. Phagocytosis of Plasmodium falciparum ring-stage parasites predicts protection against malaria. Nat Commun 2022; 13:4098. [PMID: 35835738 PMCID: PMC9281573 DOI: 10.1038/s41467-022-31640-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 06/27/2022] [Indexed: 01/13/2023] Open
Abstract
Ring-infected erythrocytes are the predominant asexual stage in the peripheral circulation but are rarely investigated in the context of acquired immunity against Plasmodium falciparum malaria. Here we compare antibody-dependent phagocytosis of ring-infected parasite cultures in samples from a controlled human malaria infection (CHMI) study (NCT02739763). Protected volunteers did not develop clinical symptoms, maintained parasitaemia below a predefined threshold of 500 parasites/μl and were not treated until the end of the study. Antibody-dependent phagocytosis of both ring-infected and uninfected erythrocytes from parasite cultures was strongly correlated with protection. A surface proteomic analysis revealed the presence of merozoite proteins including erythrocyte binding antigen-175 and -140 on ring-infected and uninfected erythrocytes, providing an additional antibody-mediated protective mechanism for their activity beyond invasion-inhibition. Competition phagocytosis assays support the hypothesis that merozoite antigens are the key mediators of this functional activity. Targeting ring-stage parasites may contribute to the control of parasitaemia and prevention of clinical malaria.
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Affiliation(s)
- Fauzia K. Musasia
- grid.5253.10000 0001 0328 4908Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Irene N. Nkumama
- grid.5253.10000 0001 0328 4908Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany ,grid.33058.3d0000 0001 0155 5938Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Roland Frank
- grid.5253.10000 0001 0328 4908Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Victor Kipkemboi
- grid.5253.10000 0001 0328 4908Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany ,grid.449481.40000 0004 0427 2011Department of Biotechnology, Hochschule Rhein-Waal, Kleve, Germany
| | - Martin Schneider
- grid.7497.d0000 0004 0492 0584Genomics and Proteomics Core Facility, German Cancer Research Center, Heidelberg, Germany
| | - Kennedy Mwai
- grid.33058.3d0000 0001 0155 5938Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya ,grid.11951.3d0000 0004 1937 1135Epidemiology and Biostatistics Division, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - Dennis O. Odera
- grid.5253.10000 0001 0328 4908Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany ,grid.33058.3d0000 0001 0155 5938Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Micha Rosenkranz
- grid.5253.10000 0001 0328 4908Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Kristin Fürle
- grid.5253.10000 0001 0328 4908Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Domitila Kimani
- grid.33058.3d0000 0001 0155 5938Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya
| | - James Tuju
- grid.33058.3d0000 0001 0155 5938Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Patricia Njuguna
- grid.33058.3d0000 0001 0155 5938Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Mainga Hamaluba
- grid.33058.3d0000 0001 0155 5938Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Melissa C. Kapulu
- grid.33058.3d0000 0001 0155 5938Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Hedda Wardemann
- grid.7497.d0000 0004 0492 0584Division of B Cell Immunology, German Cancer Research Center, Heidelberg, Germany
| | | | - Faith H. A. Osier
- grid.5253.10000 0001 0328 4908Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany ,grid.33058.3d0000 0001 0155 5938Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya ,grid.7445.20000 0001 2113 8111Department of Life Sciences, Imperial College London, London, UK
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Pasternak M, Verhoef JMJ, Wong W, Triglia T, Mlodzianoski MJ, Geoghegan N, Evelyn C, Wardak AZ, Rogers K, Cowman AF. RhopH2 and RhopH3 export enables assembly of the RhopH complex on P. falciparum-infected erythrocyte membranes. Commun Biol 2022; 5:333. [PMID: 35393572 PMCID: PMC8989874 DOI: 10.1038/s42003-022-03290-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 03/17/2022] [Indexed: 11/09/2022] Open
Abstract
RhopH complexes consists of Clag3, RhopH2 and RhopH3 and are essential for growth of Plasmodium falciparum inside infected erythrocytes. Proteins are released from rhoptry organelles during merozoite invasion and trafficked to the surface of infected erythrocytes and enable uptake of nutrients. RhopH3, unlike other RhopH proteins, is required for parasite invasion, suggesting some cellular processes RhopH proteins function as single players rather than a complex. We show the RhopH complex has not formed during merozoite invasion. Clag3 is directly released into the host cell cytoplasm, whilst RhopH2 and RhopH3 are released into the nascent parasitophorous vacuole. Export of RhopH2 and RhopH3 from the parasitophorous vacuole into the infected erythrocyte cytoplasm enables assembly of Clag3/RhopH2/RhopH3 complexes and incorporation into the host cell membrane concomitant with activation of nutrient uptake. This suggests compartmentalisation prevents premature channel assembly before intact complex is assembled at the host cell membrane.
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Affiliation(s)
- Michał Pasternak
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
- Imperial College London, London, SW7 2AZ, UK
| | - Julie M J Verhoef
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, Netherlands
| | - Wilson Wong
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
| | - Tony Triglia
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
| | - Michael J Mlodzianoski
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
| | - Niall Geoghegan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
| | - Cindy Evelyn
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
| | - Ahmad Z Wardak
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
| | - Kelly Rogers
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville, 3052, Victoria, Australia.
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3
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Native structure of the RhopH complex, a key determinant of malaria parasite nutrient acquisition. Proc Natl Acad Sci U S A 2021; 118:2100514118. [PMID: 34446549 PMCID: PMC8536402 DOI: 10.1073/pnas.2100514118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Malaria parasites invade and replicate within human red blood cells, which lack nuclei and have minimal metabolic activity. To survive, the parasites create new pathways that alter the permeability of the red blood cell membrane, allowing them to import nutrients and export waste. Here, we present the native structure of the three-membered RhopH protein complex, which plays a key role in this process. We determined the structure of this essential complex from a heterogeneous mixture of proteins enriched directly from parasite cell lysate, using a cryo-electron microscopy–enabled endogenous structural proteomics approach. The native structure of the RhopH complex in a soluble, trafficking state helps elucidate the long-standing question of how parasite transmembrane proteins are trafficked to the erythrocyte membrane. The RhopH complex is implicated in malaria parasites’ ability to invade and create new permeability pathways in host erythrocytes, but its mechanisms remain poorly understood. Here, we enrich the endogenous RhopH complex in a native soluble form, comprising RhopH2, CLAG3.1, and RhopH3, directly from parasite cell lysates and determine its atomic structure using cryo–electron microscopy (cryo-EM), mass spectrometry, and the cryoID program. CLAG3.1 is positioned between RhopH2 and RhopH3, which both share substantial binding interfaces with CLAG3.1 but make minimal contacts with each other. The forces stabilizing individual subunits include 13 intramolecular disulfide bonds. Notably, CLAG3.1 residues 1210 to 1223, previously predicted to constitute a transmembrane helix, are embedded within a helical bundle formed by residues 979 to 1289 near the C terminus of CLAG3.1. Buried in the core of the RhopH complex and largely shielded from solvent, insertion of this putative transmembrane helix into the erythrocyte membrane would likely require a large conformational rearrangement. Given the unusually high disulfide content of the complex, it is possible that such a rearrangement could be initiated by the breakage of allosteric disulfide bonds, potentially triggered by interactions at the erythrocyte membrane. This first direct observation of an exported Plasmodium falciparum transmembrane protein—in a soluble, trafficking state and with atomic details of buried putative membrane-insertion helices—offers insights into the assembly and trafficking of RhopH and other parasite-derived complexes to the erythrocyte membrane. Our study demonstrates the potential the endogenous structural proteomics approach holds for elucidating the molecular mechanisms of hard-to-isolate complexes in their native, functional forms.
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Yadavalli R, Peterson JW, Drazba JA, Sam-Yellowe TY. Trafficking and Association of Plasmodium falciparum MC-2TM with the Maurer's Clefts. Pathogens 2021; 10:pathogens10040431. [PMID: 33916455 PMCID: PMC8066109 DOI: 10.3390/pathogens10040431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/28/2021] [Accepted: 03/30/2021] [Indexed: 12/05/2022] Open
Abstract
In this study, we investigated stage specific expression, trafficking, solubility and topology of endogenous PfMC-2TM in P. falciparum (3D7) infected erythrocytes. Following Brefeldin A (BFA) treatment of parasites, PfMC-2TM traffic was evaluated using immunofluorescence with antibodies reactive with PfMC-2TM. PfMC-2TM is sensitive to BFA treatment and permeabilization of infected erythrocytes with streptolysin O (SLO) and saponin, showed that the N and C-termini of PfMC-2TM are exposed to the erythrocyte cytoplasm with the central portion of the protein protected in the MC membranes. PfMC-2TM was expressed as early as 4 h post invasion (hpi), was tightly colocalized with REX-1 and trafficked to the erythrocyte membrane without a change in solubility. PfMC-2TM associated with the MC and infected erythrocyte membrane and was resistant to extraction with alkaline sodium carbonate, suggestive of protein-lipid interactions with membranes of the MC and erythrocyte. PfMC-2TM is an additional marker of the nascent MCs.
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Affiliation(s)
- Raghavendra Yadavalli
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, OH 44115, USA;
| | - John W. Peterson
- Imaging Core Facility, The Cleveland Clinic, Cleveland, OH 44195, USA; (J.W.P.); (J.A.D.)
| | - Judith A. Drazba
- Imaging Core Facility, The Cleveland Clinic, Cleveland, OH 44195, USA; (J.W.P.); (J.A.D.)
| | - Tobili Y. Sam-Yellowe
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, OH 44115, USA;
- Correspondence: ; Tel.: +1-216-687-2068
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Counihan NA, Modak JK, de Koning-Ward TF. How Malaria Parasites Acquire Nutrients From Their Host. Front Cell Dev Biol 2021; 9:649184. [PMID: 33842474 PMCID: PMC8027349 DOI: 10.3389/fcell.2021.649184] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/24/2021] [Indexed: 01/01/2023] Open
Abstract
Plasmodium parasites responsible for the disease malaria reside within erythrocytes. Inside this niche host cell, parasites internalize and digest host hemoglobin to source amino acids required for protein production. However, hemoglobin does not contain isoleucine, an amino acid essential for Plasmodium growth, and the parasite cannot synthesize it de novo. The parasite is also more metabolically active than its host cell, and the rate at which some nutrients are consumed exceeds the rate at which they can be taken up by erythrocyte transporters. To overcome these constraints, Plasmodium parasites increase the permeability of the erythrocyte membrane to isoleucine and other low-molecular-weight solutes it requires for growth by forming new permeation pathways (NPPs). In addition to the erythrocyte membrane, host nutrients also need to cross the encasing parasitophorous vacuole membrane (PVM) and the parasite plasma membrane to access the parasite. This review outlines recent advances that have been made in identifying the molecular constituents of the NPPs, the PVM nutrient channel, and the endocytic apparatus that transports host hemoglobin and identifies key knowledge gaps that remain. Importantly, blocking the ability of Plasmodium to source essential nutrients is lethal to the parasite, and thus, components of these key pathways represent potential antimalaria drug targets.
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Affiliation(s)
| | - Joyanta K Modak
- School of Medicine, Deakin University, Waurn Ponds, VIC, Australia
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Plasmodium falciparum Clag9-Associated PfRhopH Complex Is Involved in Merozoite Binding to Human Erythrocytes. Infect Immun 2020; 88:IAI.00504-19. [PMID: 31712270 DOI: 10.1128/iai.00504-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/01/2019] [Indexed: 02/05/2023] Open
Abstract
Cytoadherence-linked asexual gene 9 (Clag9), a conserved Plasmodium protein expressed during the asexual blood stages, is involved in the cytoadherence of infected red blood cells (RBCs) to the endothelial lining of blood vessels. Here, we show that Plasmodium falciparum Clag9 (PfClag9) is a component of the PfClag9-RhopH complex that is involved in merozoite binding to human erythrocytes. To characterize PfClag9, we expressed four fragments of PfClag9, encompassing the entire protein. Immunostaining analysis using anti-PfClag9 antibodies showed expression and localization of PfClag9 at the apical end of the merozoites. Mass spectrometric analysis of merozoite extracts after immunoprecipitation using anti-PfClag9 antibody identified P. falciparum rhoptry-associated protein 1 (PfRAP1), PfRAP2, PfRAP3, PfRhopH2, and PfRhopH3 as associated proteins. The identified rhoptry proteins were expressed, and their association with PfClag9 domains was assessed by using protein-protein interaction tools. We further showed that PfClag9 binds human RBCs by interacting with the glycophorin A-band 3 receptor-coreceptor complex. In agreement with its cellular localization, PfClag9 was strongly recognized by antibodies generated during natural infection. Mice immunized with the C-terminal domain of PfClag9 were partially protected against a subsequent challenge infection with Plasmodium berghei, further supporting a biological role of PfClag9 during natural infection. Taken together, these results provide direct evidence for the existence of a PfRhopH-Clag9 complex on the Plasmodium merozoite surface that binds to human RBCs.
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7
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RhopH3, rhoptry gene conserved in the free-living alveolate flagellate Colpodella sp. (Apicomplexa). Eur J Protistol 2019; 71:125637. [PMID: 31689662 DOI: 10.1016/j.ejop.2019.125637] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 08/05/2019] [Accepted: 08/20/2019] [Indexed: 11/22/2022]
Abstract
In this study, we investigated morphological, immunological and molecular characteristics of Colpodella sp. (American Type Culture Collection 50594) in a diprotist culture containing Bodo caudatus as prey using Plasmodium rhoptry specific antibodies and oligonucleotide primers targeting Plasmodium falciparum rhoptry genes. In culture, Colpodella sp. attached to its prey using the apical end with attachment lasting for approximately 20 min while the cytoplasmic contents of the prey were aspirated into the posterior food vacuole of Colpodella sp. Encystment of Colpodella sp. was observed following feeding. Indirect immunofluorescence assay (IFA) and confocal microscopy using P. falciparum rhoptry specific antibodies showed intense reactivity with cytoplasmic vesicles of Colpodella sp. Bodo caudatus from diprotist and monoprotist (ATCC 30395) cultures showed weak background reactivity. Giemsa staining permitted differentiation of both protists. Genomic DNA isolated from the diprotist culture was used in polymerase chain reaction (PCR) with oligonucleotide primers targeting the P. falciparum rhoptry genes RhopH3, RhopH1/Clag3.2 and RAMA. Primers targeting exon 7 of the P. falciparum RhopH3 gene amplified an approximately 2 kb DNA fragment from the diprotist DNA template. DNA sequence and BLAST search analysis of the amplified product from diprotist DNA identified the RhopH3 gene demonstrating that the RhopH3 gene is conserved in Colpodella sp.
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8
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Sherling ES, Knuepfer E, Brzostowski JA, Miller LH, Blackman MJ, van Ooij C. The Plasmodium falciparum rhoptry protein RhopH3 plays essential roles in host cell invasion and nutrient uptake. eLife 2017; 6. [PMID: 28252384 PMCID: PMC5365315 DOI: 10.7554/elife.23239] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 02/26/2017] [Indexed: 11/18/2022] Open
Abstract
Merozoites of the protozoan parasite responsible for the most virulent form of malaria, Plasmodium falciparum, invade erythrocytes. Invasion involves discharge of rhoptries, specialized secretory organelles. Once intracellular, parasites induce increased nutrient uptake by generating new permeability pathways (NPP) including a Plasmodium surface anion channel (PSAC). RhopH1/Clag3, one member of the three-protein RhopH complex, is important for PSAC/NPP activity. However, the roles of the other members of the RhopH complex in PSAC/NPP establishment are unknown and it is unclear whether any of the RhopH proteins play a role in invasion. Here we demonstrate that RhopH3, the smallest component of the complex, is essential for parasite survival. Conditional truncation of RhopH3 substantially reduces invasive capacity. Those mutant parasites that do invade are defective in nutrient import and die. Our results identify a dual role for RhopH3 that links erythrocyte invasion to formation of the PSAC/NPP essential for parasite survival within host erythrocytes. DOI:http://dx.doi.org/10.7554/eLife.23239.001 Malaria is a life-threatening disease that affects millions of people around the world. The parasites that cause malaria have a complex life cycle that involves infecting both mosquitoes and mammals, including humans. In humans, the parasites spend part of their life cycle inside red blood cells, which causes the symptoms of the disease. In order to survive and multiply, malaria parasites need to make the red blood cell more permeable so that it can absorb nutrients from the blood stream and get rid of the toxic waste products they generate. It remains unclear how the parasites do this, but previous research has shown that the parasites produce channel-like proteins that make red blood cells more permeable to nutrients. One of the proteins involved in this process forms part of a complex with two other proteins, called RhopH2 and RhopH3. It is not known what these other two proteins do, and whether they are necessary for creating the new nutrient channels. Sherling et al. studied the RhopH3 protein to see if it is required to make red blood cells more permeable. The experiments used a genetically modified version of the parasite, in which RhopH3 no longer interacted with the two other proteins. The findings show that RhopH3 has two important roles: first, parasites need it to invade the red blood cells, and second, parasites cannot get nutrients into the red blood cell without RhopH3. Most antimalarial drugs work by preventing parasite replication in red blood cells, but parasites are becoming increasingly resistant to these drugs. Understanding which proteins allow parasites to invade and grow within blood cells will further the development of new malaria medication. The next step will be to understand the molecular mechanisms by which RhopH3 promotes invasion and subsequently facilitates nutrient uptake, and will help researchers to explore its potential as a drug target. DOI:http://dx.doi.org/10.7554/eLife.23239.002
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Affiliation(s)
- Emma S Sherling
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom.,Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, United States
| | - Ellen Knuepfer
- Malaria Parasitology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Joseph A Brzostowski
- Laboratory of Immunogenetics Imaging Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, United States
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, United States
| | - Michael J Blackman
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom.,Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christiaan van Ooij
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
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Counihan NA, Chisholm SA, Bullen HE, Srivastava A, Sanders PR, Jonsdottir TK, Weiss GE, Ghosh S, Crabb BS, Creek DJ, Gilson PR, de Koning-Ward TF. Plasmodium falciparum parasites deploy RhopH2 into the host erythrocyte to obtain nutrients, grow and replicate. eLife 2017; 6. [PMID: 28252383 PMCID: PMC5365316 DOI: 10.7554/elife.23217] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 02/26/2017] [Indexed: 11/13/2022] Open
Abstract
Plasmodium falciparum parasites, the causative agents of malaria, modify their host erythrocyte to render them permeable to supplementary nutrient uptake from the plasma and for removal of toxic waste. Here we investigate the contribution of the rhoptry protein RhopH2, in the formation of new permeability pathways (NPPs) in Plasmodium-infected erythrocytes. We show RhopH2 interacts with RhopH1, RhopH3, the erythrocyte cytoskeleton and exported proteins involved in host cell remodeling. Knockdown of RhopH2 expression in cycle one leads to a depletion of essential vitamins and cofactors and decreased de novo synthesis of pyrimidines in cycle two. There is also a significant impact on parasite growth, replication and transition into cycle three. The uptake of solutes that use NPPs to enter erythrocytes is also reduced upon RhopH2 knockdown. These findings provide direct genetic support for the contribution of the RhopH complex in NPP activity and highlight the importance of NPPs to parasite survival.
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Affiliation(s)
| | | | | | - Anubhav Srivastava
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
| | | | - Thorey K Jonsdottir
- Burnet Institute, Melbourne, Australia.,Department of Medicine, University of Melbourne, Parkville, Australia
| | | | - Sreejoyee Ghosh
- School of Medicine, Deakin University, Waurn Ponds, Australia
| | - Brendan S Crabb
- Burnet Institute, Melbourne, Australia.,Department of Medicine, University of Melbourne, Parkville, Australia.,Monash University, Melbourne, Australia
| | - Darren J Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
| | - Paul R Gilson
- Burnet Institute, Melbourne, Australia.,Monash University, Melbourne, Australia
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10
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Abstract
PURPOSE OF REVIEW Malaria is caused by the infection and proliferation of parasites from the genus Plasmodium in red blood cells (RBCs). A free Plasmodium parasite, or merozoite, released from an infected RBC must invade another RBC host cell to sustain a blood-stage infection. Here, we review recent advances on RBC invasion by Plasmodium merozoites, focusing on specific molecular interactions between host and parasite. RECENT FINDINGS Recent work highlights the central role of host-parasite interactions at virtually every stage of RBC invasion by merozoites. Biophysical experiments have for the first time measured the strength of merozoite-RBC attachment during invasion. For P. falciparum, there have been many key insights regarding the invasion ligand PfRh5 in particular, including its influence on host species tropism, a co-crystal structure with its RBC receptor basigin, and its suitability as a vaccine target. For P. vivax, researchers identified the origin and emergence of the parasite from Africa, demonstrating a natural link to the Duffy-negative RBC variant in African populations. For the simian parasite P. knowlesi, zoonotic invasion into human cells is linked to RBC age, which has implications for parasitemia during an infection and thus malaria. SUMMARY New studies of the molecular and cellular mechanisms governing RBC invasion by Plasmodium parasites have shed light on various aspects of parasite biology and host cell tropism, and indicate opportunities for malaria control.
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11
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Yadavalli R, Sam-Yellowe T. HeLa Based Cell Free Expression Systems for Expression of Plasmodium Rhoptry Proteins. J Vis Exp 2015:e52772. [PMID: 26131624 DOI: 10.3791/52772] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Malaria causes significant global morbidity and mortality. No routine vaccine is currently available. One of the major reasons for lack of a vaccine is the challenge of identifying suitable vaccine candidates. Malarial proteins expressed using prokaryotic and eukaryotic cell based expression systems are poorly glycosylated, generally insoluble and undergo improper folding leading to reduced immunogenicity. The wheat germ, rabbit reticulocyte lysate and Escherichia coli lysate cell free expression systems are currently used for expression of malarial proteins. However, the length of expression time and improper glycosylation of proteins still remains a challenge. We demonstrate expression of Plasmodium proteins in vitro using HeLa based cell free expression systems, termed "in vitro human cell free expression systems". The 2 HeLa based cell free expression systems transcribe mRNA in 75 min and 3 µl of transcribed mRNA is sufficient to translate proteins in 90 min. The 1-step expression system is a transcription and translation coupled expression system; the transcription and co-translation occurs in 3 hr. The process can also be extended for 6 hr by providing additional energy. In the 2-step expression system, mRNA is first transcribed and then added to the translation mix for protein expression. We describe how to express malaria proteins; a hydrophobic PF3D7_0114100 Maurer's Cleft - 2 transmembrane (PfMC-2TM) protein, a hydrophilic PF3D7_0925900 protein and an armadillo repeats containing protein PF3D7_1361800, using the HeLa based cell free expression system. The proteins are expressed in micro volumes employing 2-step and 1-step expression strategies. An affinity purification method to purify 25 µl of proteins expressed using the in vitro human cell free expression system is also described. Protein yield is determined by Bradford's assay and the expressed and purified proteins can be confirmed by western blotting analysis. Expressed recombinant proteins can be used for immunizations, immunoassays and protein sequencing.
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Affiliation(s)
- Raghavendra Yadavalli
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University;
| | - Tobili Sam-Yellowe
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University
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12
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The conserved clag multigene family of malaria parasites: essential roles in host-pathogen interaction. Drug Resist Updat 2014; 18:47-54. [PMID: 25467627 DOI: 10.1016/j.drup.2014.10.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The clag multigene family is strictly conserved in malaria parasites, but absent from neighboring genera of protozoan parasites. Early research pointed to roles in merozoite invasion and infected cell cytoadherence, but more recent studies have implicated channel-mediated uptake of ions and nutrients from host plasma. Here, we review the current understanding of this gene family, which appears to be central to host-parasite interactions and an important therapeutic target.
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Zhang W, Blackman LM, Hardham AR. Transient fusion and selective secretion of vesicle proteins in Phytophthora nicotianae zoospores. PeerJ 2013; 1:e221. [PMID: 24392285 PMCID: PMC3869178 DOI: 10.7717/peerj.221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 11/13/2013] [Indexed: 12/25/2022] Open
Abstract
Secretion of pathogen proteins is crucial for the establishment of disease in animals and plants. Typically, early interactions between host and pathogen trigger regulated secretion of pathogenicity factors that function in pathogen adhesion and host penetration. During the onset of plant infection by spores of the Oomycete, Phytophthora nicotianae, proteins are secreted from three types of cortical vesicles. Following induction of spore encystment, two vesicle types undergo full fusion, releasing their entire contents onto the cell surface. However, the third vesicle type, so-called large peripheral vesicles, selectively secretes a small Sushi domain-containing protein, PnCcp, while retaining a large glycoprotein, PnLpv, before moving away from the plasma membrane. Selective secretion of PnCcp is associated with its compartmentalization within the vesicle periphery. Pharmacological inhibition of dynamin function, purportedly in vesicle fission, by dynasore treatment provides evidence that selective secretion of PnCcp requires transient fusion of the large peripheral vesicles. This is the first report of selective protein secretion via transient fusion outside mammalian cells. Selective secretion is likely to be an important aspect of plant infection by this destructive pathogen.
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Affiliation(s)
- Weiwei Zhang
- Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University , Canberra, ACT , Australia
| | - Leila M Blackman
- Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University , Canberra, ACT , Australia
| | - Adrienne R Hardham
- Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University , Canberra, ACT , Australia
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Counihan NA, Kalanon M, Coppel RL, de Koning-Ward TF. Plasmodium rhoptry proteins: why order is important. Trends Parasitol 2013; 29:228-36. [PMID: 23570755 DOI: 10.1016/j.pt.2013.03.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 02/28/2013] [Accepted: 03/04/2013] [Indexed: 11/26/2022]
Abstract
Apicomplexan parasites, including the Plasmodium species that cause malaria, contain three unusual apical secretory organelles (micronemes, rhoptries, and dense granules) that are required for the infection of new host cells. Because of their specialized nature, the majority of proteins secreted from these organelles are unique to Apicomplexans and are consequently poorly characterized. Although rhoptry proteins of Plasmodium have been implicated in events central to invasion, there is growing evidence to suggest that proteins originating from this organelle play key roles downstream of parasite entry into the host cell. Here we discuss recent work that has advanced our knowledge of rhoptry protein trafficking and function, and highlight areas of research that require further investigation.
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Siddiqui FA, Dhawan S, Singh S, Singh B, Gupta P, Pandey A, Mohmmed A, Gaur D, Chitnis CE. A thrombospondin structural repeat containing rhoptry protein from Plasmodium falciparum mediates erythrocyte invasion. Cell Microbiol 2013; 15:1341-56. [PMID: 23387921 DOI: 10.1111/cmi.12118] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 11/30/2012] [Accepted: 01/18/2013] [Indexed: 12/01/2022]
Abstract
Host cell invasion by Plasmodium falciparum requires multiple molecular interactions between host receptors and parasite ligands. A family of parasite proteins, which contain the conserved thrombospondin structural repeat motif (TSR), has been implicated in receptor binding during invasion. In this study we have characterized the functional role of a TSR containing blood stage protein referred to as P. falciparum thrombospondin related apical merozoite protein (PfTRAMP). Both native and recombinant PfTRAMP bind untreated as well as neuraminidase, trypsin or chymotrypsin-treated human erythrocytes. PfTRAMP is localized in the rhoptry bulb and is secreted during invasion. Adhesion of microneme protein EBA175 with its erythrocyte receptor glycophorin A provides the signal that triggers release of PfTRAMP from the rhoptries. Rabbit antibodies raised against PfTRAMP block erythrocyte invasion by P. falciparum suggesting that PfTRAMP plays an important functional role in invasion. Combination of antibodies against PfTRAMP with antibodies against microneme protein EBA175 provides an additive inhibitory effect against invasion. These observations suggest that targeting multiple conserved parasite ligands involved in different steps of invasion may provide an effective strategy for the development of vaccines against blood stage malaria parasites.
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Affiliation(s)
- Faiza Amber Siddiqui
- Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
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Deponte M, Hoppe HC, Lee MC, Maier AG, Richard D, Rug M, Spielmann T, Przyborski JM. Wherever I may roam: Protein and membrane trafficking in P. falciparum-infected red blood cells. Mol Biochem Parasitol 2012; 186:95-116. [DOI: 10.1016/j.molbiopara.2012.09.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/21/2012] [Accepted: 09/24/2012] [Indexed: 11/27/2022]
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Wang B, Lu F, Cheng Y, Li J, Ito D, Sattabongkot J, Tsuboi T, Han ET. Identification and characterization of the Plasmodium falciparum RhopH2 ortholog in Plasmodium vivax. Parasitol Res 2012; 112:585-93. [PMID: 23097184 DOI: 10.1007/s00436-012-3170-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 10/08/2012] [Indexed: 11/28/2022]
Abstract
Plasmodium vivax is one of the most important human malaria species that is geographically widely endemic and potentially affects a larger number of people than its more notorious cousin, Plasmodium falciparum. During invasion of red blood cells, the parasite requires the intervention of high molecular weight complex rhoptry proteins (RhopH) that are also essential for cytoadherence. PfRhopH2, a member of the RhopH multigene family, has been characterized as being crucial during P. falciparum infection. This study describes identifying and characterizing the pfrhoph2 orthologous gene in P. vivax (hereinafter named pvrhoph2). The PvRhopH2 is a 1,369-amino acid polypeptide encoded by PVX_099930 gene, for which orthologous genes have been identified in other Plasmodium species by bioinformatic approaches. Both P. falciparum and P. vivax genes contain nine introns, and there is a high degree of similarity between the deduced amino acid sequences of the two proteins. Moreover, PvRhopH2 contains a signal peptide at its N-terminus and 12 cysteines predominantly in its C-terminal half. PvRhopH2 is localized in one of the apical organelles of the merozoite, the rhoptry, and the localization pattern is similar to that of PfRhopH2 in P. falciparum. The recombinant PvRhopH2 protein is recognized by serum antibodies of patients naturally exposed to P. vivax, suggesting that PvRhopH2 is immunogenic in humans.
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Affiliation(s)
- Bo Wang
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Hyoja2-dong, Chuncheon, Gangwon-do 200-701, Republic of Korea
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18
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In vitro human cell-free expression system for synthesis of malaria proteins. Parasitol Res 2012; 111:2461-5. [PMID: 22782471 DOI: 10.1007/s00436-012-3014-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 06/15/2012] [Indexed: 10/28/2022]
Abstract
In this study, we performed cell-free expression of Plasmodium proteins using the in vitro human cell-free protein expression systems for DNA and mRNA. Malaria rhoptry genes (PFc14_0344, PFc0120w, PY01759, PY00763, PY07482, and PY04666) and a Maurer's cleft gene (PfA0680c) identified from proteome analysis studies were cloned into the pT7CFE1-CHis expression vector. Following a coupled transcription-translation procedure, expressed proteins were analyzed by His-tag staining and by western blotting using protein specific antibodies and nickel-horseradish peroxidase (HRP) for histidine detection. Antibodies against whole rhoptries of Plasmodium falciparum and Plasmodium yoelii merozoites and antibodies specific for the PfMC-2TM protein identified translated proteins. The rhoptry specific antibodies exhibited cross reactivity among the expressed proteins of P. falciparum and P. yoelii. The results demonstrate that the in vitro human cell-free protein expression system is suitable for rapid expression and screening of malaria vaccine candidates and diagnostic biomarkers.
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Philipp S, Jakoby T, Tholey A, Janssen O, Leippe M, Gelhaus C. Cationic detergents enable the separation of membrane proteins of Plasmodium falciparum-infected erythrocytes by 2D gel electrophoresis. Electrophoresis 2012; 33:1120-8. [DOI: 10.1002/elps.201100520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Stephan Philipp
- Department of Zoophysiology; Zoological Institute; University of Kiel; Kiel; Germany
| | - Thomas Jakoby
- Division for Systematic Proteome Research,; Institute for Experimental Medicine; University of Kiel; Kiel; Germany
| | - Andreas Tholey
- Division for Systematic Proteome Research,; Institute for Experimental Medicine; University of Kiel; Kiel; Germany
| | - Ottmar Janssen
- Molecular Immunology,; Institute for Immunology; University of Kiel; Kiel; Germany
| | - Matthias Leippe
- Department of Zoophysiology; Zoological Institute; University of Kiel; Kiel; Germany
| | - Christoph Gelhaus
- Department of Zoophysiology; Zoological Institute; University of Kiel; Kiel; Germany
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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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Saleh S, Moreno-Molek S, Perera I, Riga A, Sam-Yellowe T, Bayachou M. Probe functionalization with a Rhop-3 antibody: toward a Rhop-3 antigen immunosensor for detection of malaria. Anal Bioanal Chem 2012; 402:2379-84. [DOI: 10.1007/s00216-012-5735-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 12/22/2011] [Accepted: 01/10/2012] [Indexed: 10/14/2022]
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22
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Kuss C, Gan CS, Gunalan K, Bozdech Z, Sze SK, Preiser PR. Quantitative proteomics reveals new insights into erythrocyte invasion by Plasmodium falciparum. Mol Cell Proteomics 2011; 11:M111.010645. [PMID: 22023809 DOI: 10.1074/mcp.m111.010645] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Differential expression of ligands in the human malaria parasite Plasmodium falciparum enables it to recognize different receptors on the erythrocyte surface, thereby providing alternative invasion pathways. Switching of invasion from using sialated to nonsialated erythrocyte receptors has been linked to the transcriptional activation of a single parasite ligand. We have used quantitative proteomics to show that in addition to this single known change, there are a significant number of changes in the expression of merozoite proteins that are regulated independent of transcription during invasion pathway switching. These results demonstrate a so far unrecognized mechanism by which the malaria parasite is able to adapt to variations in the host cell environment by post-transcriptional regulation.
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Affiliation(s)
- Claudia Kuss
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
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Moreno-Perez DA, Mongui A, Soler LN, Sanchez-Ladino M, Patarroyo MA. Identifying and characterizing a member of the RhopH1/Clag family in Plasmodium vivax. Gene 2011; 481:17-23. [PMID: 21513780 DOI: 10.1016/j.gene.2011.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 03/05/2011] [Accepted: 03/28/2011] [Indexed: 10/18/2022]
Abstract
Plasmodium vivax malaria caused is a public health problem that produces very high morbidity worldwide. During invasion of red blood cells the parasite requires the intervention of high molecular weight complex rhoptry proteins that are also essential for cytoadherence. PfClag9, a member of the RhopH multigene family, has been identified as being critical during Plasmodium falciparum infection. This study describes identifying and characterizing the pfclag9 ortholog in P. vivax (hereinafter named pvclag7). The pvclag7 gene is transcribed at the end of the intraerythrocytic cycle and is recognized by sera from humans who have been infected by P. vivax. PvClag7 subcellular localization has been also determined and, similar to what occurs with PfClag9, it co-localize with other proteins from the Rhoptry high molecular weight complex.
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Affiliation(s)
- Darwin A Moreno-Perez
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá, Colombia.
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Ito D, Han ET, Takeo S, Thongkukiatkul A, Otsuki H, Torii M, Tsuboi T. Plasmodial ortholog of Toxoplasma gondii rhoptry neck protein 3 is localized to the rhoptry body. Parasitol Int 2011; 60:132-8. [PMID: 21237287 DOI: 10.1016/j.parint.2011.01.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 12/24/2010] [Accepted: 01/07/2011] [Indexed: 11/24/2022]
Abstract
The proteins in apical organelles of Plasmodium falciparum merozoite play an important role in invasion into erythrocytes. Several rhoptry neck (RON) proteins have been identified in rhoptry proteome of the closely-related apicomplexan parasite, Toxoplasma gondii. Recently, three of P. falciparum proteins orthologous to TgRON proteins, PfRON2, 4 and 5, were found to be located in the rhoptry neck and interact with the micronemal protein apical membrane antigen 1 (PfAMA1) to form a moving junction complex that helps the invasion of merozoite into erythrocyte. However, the other P. falciparum RON proteins have yet to be characterized. Here, we determined that "PFL2505c" (hereafter referred to as pfron3) is the ortholog of the tgron3 in P. falciparum and characterized its protein expression profile, subcellular localization, and complex formation. Protein expression analysis revealed that PfRON3 was expressed primarily in late schizont stage parasites. Immunofluorescence microscopy (IFA) showed that PfRON3 localizes in the apical region of P. falciparum merozoites. Results from immunoelectron microscopy, along with IFA, clarified that PfRON3 localizes in the rhoptry body and not in the rhoptry neck. Even after erythrocyte invasion, PfRON3 was still detectable at the parasite ring stage in the parasitophorous vacuole. Moreover, co-immunoprecipitation studies indicated that PfRON3 interacts with PfRON2 and PfRON4, but not with PfAMA1. These results suggest that PfRON3 partakes in the novel PfRON complex formation (PfRON2, 3, and 4), but not in the moving junction complex (PfRON2, 4, 5, and PfAMA1). The novel PfRON complex, as well as the moving junction complex, might play a fundamental role in erythrocyte invasion by merozoite stage parasites.
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Affiliation(s)
- Daisuke Ito
- Cell-Free Science and Technology Research Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
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Global identification of multiple substrates for Plasmodium falciparum SUB1, an essential malarial processing protease. Infect Immun 2011; 79:1086-97. [PMID: 21220481 DOI: 10.1128/iai.00902-10] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The protozoan pathogen responsible for the most severe form of human malaria, Plasmodium falciparum, replicates asexually in erythrocytes within a membrane-bound parasitophorous vacuole (PV). Following each round of intracellular growth, the PV membrane (PVM) and host cell membrane rupture to release infectious merozoites in a protease-dependent process called egress. Previous work has shown that, just prior to egress, an essential, subtilisin-like parasite protease called PfSUB1 is discharged into the PV lumen, where it directly cleaves a number of important merozoite surface and PV proteins. These include the essential merozoite surface protein complex MSP1/6/7 and members of a family of papain-like putative proteases called SERA (serine-rich antigen) that are implicated in egress. To determine whether PfSUB1 has additional, previously unrecognized substrates, we have performed a bioinformatic and proteomic analysis of the entire late asexual blood stage proteome of the parasite. Our results demonstrate that PfSUB1 is responsible for the proteolytic processing of a range of merozoite, PV, and PVM proteins, including the rhoptry protein RAP1 (rhoptry-associated protein 1) and the merozoite surface protein MSRP2 (MSP7-related protein-2). Our findings imply multiple roles for PfSUB1 in the parasite life cycle, further supporting the case for considering the protease as a potential new antimalarial drug target.
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Ranjan R, Chugh M, Kumar S, Singh S, Kanodia S, Hossain MJ, Korde R, Grover A, Dhawan S, Chauhan VS, Reddy VS, Mohmmed A, Malhotra P. Proteome analysis reveals a large merozoite surface protein-1 associated complex on the Plasmodium falciparum merozoite surface. J Proteome Res 2010; 10:680-91. [PMID: 21175202 DOI: 10.1021/pr100875y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Plasmodium merozoite surface protein-1 (MSP-1) is an essential antigen for the merozoite invasion of erythrocytes. A key challenge to the development of an effective malaria vaccine that can block the erythrocyte invasion is to establish the molecular interaction(s) among the parasite surface proteins as well as with the host cell encoded receptors. In the present study, we applied molecular interactions and proteome approaches to identify PfMSP-1 associated complex on the merozoite surface. Proteomic analysis identified a major malaria surface protein, PfRhopH3 interacting with PfMSP-1(42). Pull-down experiments with merozoite lysate using anti-PfMSP-1 or anti-PfRhopH3 antibodies showed 16 bands that when identified by tandem mass spectrometry corresponded to11 parasite proteins: PfMSP-3, PfMSP-6, PfMSP-7, PfMSP-9, PfRhopH3, PfRhopH1, PfRAP-1, PfRAP-2, and two RAP domain containing proteins. This MSP-1 associated complex was specifically seen at schizont/merozoite stages but not the next ring stage. We could also identify many of these proteins in culture supernatant, suggesting the shedding of the complex. Interestingly, the PfRhopH3 protein also showed binding to the human erythrocyte and anti-PfRhopH3 antibodies blocked the erythrocyte invasion of the merozoites. These results have potential implications in the development of PfMSP-1 based blood stage malaria vaccine.
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Affiliation(s)
- Ravi Ranjan
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
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Proellocks NI, Coppel RL, Waller KL. Dissecting the apicomplexan rhoptry neck proteins. Trends Parasitol 2010; 26:297-304. [PMID: 20347614 DOI: 10.1016/j.pt.2010.02.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 11/13/2009] [Accepted: 02/26/2010] [Indexed: 10/19/2022]
Abstract
Apicomplexan parasites possess specialized secretory organelles (rhoptries and micronemes) that release their contents during host cell invasion. Although the rhoptries were once thought to be merely a bulbous 'protein reservoir' connected to an anterior neck region, the localization of a protein specifically to the neck suggested that this region was more than just a duct. Recent studies have shown that the rhoptry neck sub-compartment possesses a distinct protein repertoire. Some of these proteins share common features, including conservation across the phylum and involvement in tight-junction formation. A sub-group of rhoptry neck proteins, the RONs, their association with the microneme protein apical membrane antigen AMA1, and their involvement in invasion are discussed.
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Molecular characterizations of three distinctBabesia gibsonirhoptry-associated protein-1s (RAP-1s). Parasitology 2009; 136:1147-60. [DOI: 10.1017/s003118200999045x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYThree cDNAs encoding rhoptry-associated protein 1 (RAP-1) homologues were found in theBabesia gibsoniEST database. Based on similarities to BgRAP-1a, which was identified previously by serological screening of a cDNA merozoite library, the two new genes were designatedBgRAP-1b(33·7%) andBgRAP-1c(57%). Mice antiserum raised against each recombinant protein reacted specifically withB. gibsoniparasites as determined by Western blotting, which showed native molecular sizes of the BgRAP-1a (51 kDa), BgRAP-1b (53 kDa) and BgRAP-1c (47 kDa) consistent with predictable molecular weights. Immunofluoresence using these antibodies revealed localization of all BgRAP-1s within the matrix of merozoites; however, BgRAP-1a appeared to diverge from the other two when it was found secreted into the cytoplasm of infected erythrocytes. Apical localization of all 3 BgRAP-1s during the extracellular stage of the parasite combined with their ability to bind a canine erythrocyte membrane fraction was suggestive of a role for these proteins in erythrocyte attachment. Lastly, the ability of these recombinant proteins to be used as diagnostic reagents was tested by ELISA and the sensitivities of BgRAP-1a and BgRAP-1c were found increased through N-terminal truncation. Taken together, our data suggest divergent roles for the 3 BgRAP-1s in the merozoite stage ofB. gibsoni.
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Nevin WD, Dacks JB. Repeated secondary loss of adaptin complex genes in the Apicomplexa. Parasitol Int 2009; 58:86-94. [DOI: 10.1016/j.parint.2008.12.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2008] [Revised: 12/09/2008] [Accepted: 12/09/2008] [Indexed: 10/21/2022]
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Proteins of the Plasmodium falciparum two transmembrane Maurer’s cleft protein family, PfMC-2TM, and the 130 kDa Maurer’s cleft protein define different domains of the infected erythrocyte intramembranous network. Parasitol Res 2009; 104:875-91. [DOI: 10.1007/s00436-008-1270-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Accepted: 11/07/2008] [Indexed: 10/21/2022]
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Rodriguez M, Lustigman S, Montero E, Oksov Y, Lobo CA. PfRH5: a novel reticulocyte-binding family homolog of plasmodium falciparum that binds to the erythrocyte, and an investigation of its receptor. PLoS One 2008; 3:e3300. [PMID: 18827878 PMCID: PMC2553180 DOI: 10.1371/journal.pone.0003300] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 09/08/2008] [Indexed: 11/18/2022] Open
Abstract
Multiple interactions between parasite ligands and their receptors on the human erythrocyte are a condition of successful Plasmodium falciparum invasion. The identification and characterization of these receptors presents a major challenge in the effort to understand the mechanism of invasion and to develop the means to prevent it. We describe here a novel member of the reticulocyte-binding family homolog (RH) of P. falciparum, PfRH5, and show that it binds to a previously unrecognized receptor on the RBC. PfRH5 is expressed as a 63 kDa protein and localized at the apical end of the invasive merozoite. We have expressed a fragment of PfRH5 which contains the RBC-binding domain and exhibits the same pattern of interactions with the RBC as the parent protein. Attachment is inhibited if the target cells are exposed to high concentrations of trypsin, but not to lower concentrations or to chymotrypsin or neuraminidase. We have determined the affinity, copy number and apparent molecular mass of the receptor protein. Thus, we have shown that PfRH5 is a novel erythrocyte-binding ligand and the identification and partial characterization of the new RBC receptor may indicate the existence of an unrecognized P. falciparum invasion pathway.
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Affiliation(s)
- Marilis Rodriguez
- Laboratory of Blood-Borne Parasites, Lindsley Kimball Research Institute, The New York Blood Center, New York, New York, United States of America
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley Kimball Research Institute, The New York Blood Center, New York, New York, United States of America
| | - Estrella Montero
- Laboratory of Blood-Borne Parasites, Lindsley Kimball Research Institute, The New York Blood Center, New York, New York, United States of America
| | - Yelena Oksov
- Electron Microscopy, Lindsley Kimball Research Institute, The New York Blood Center, New York, New York, United States of America
| | - Cheryl A. Lobo
- Laboratory of Blood-Borne Parasites, Lindsley Kimball Research Institute, The New York Blood Center, New York, New York, United States of America
- * E-mail:
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Rodriguez LE, Curtidor H, Urquiza M, Cifuentes G, Reyes C, Patarroyo ME. Intimate Molecular Interactions of P. falciparum Merozoite Proteins Involved in Invasion of Red Blood Cells and Their Implications for Vaccine Design. Chem Rev 2008; 108:3656-705. [DOI: 10.1021/cr068407v] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Hernando Curtidor
- Fundación Instituto de Inmunología de Colombia, Carrera 50 No. 26-00, Bogotá, Colombia
| | - Mauricio Urquiza
- Fundación Instituto de Inmunología de Colombia, Carrera 50 No. 26-00, Bogotá, Colombia
| | - Gladys Cifuentes
- Fundación Instituto de Inmunología de Colombia, Carrera 50 No. 26-00, Bogotá, Colombia
| | - Claudia Reyes
- Fundación Instituto de Inmunología de Colombia, Carrera 50 No. 26-00, Bogotá, Colombia
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Pinzón CG, Curtidor H, Reyes C, Méndez D, Patarroyo ME. Identification of Plasmodium falciparum RhopH3 protein peptides that specifically bind to erythrocytes and inhibit merozoite invasion. Protein Sci 2008; 17:1719-30. [PMID: 18593818 DOI: 10.1110/ps.035923.108] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The identification of sequences involved in binding to erythrocytes is an important step for understanding the molecular basis of merozoite-erythrocyte interactions that take place during invasion of the Plasmodium falciparum malaria parasite into host cells. Several molecules located in the apical organelles (micronemes, rhoptry, dense granules) of the invasive-stage parasite are essential for erythrocyte recognition, invasion, and establishment of the nascent parasitophorous vacuole. Particularly, it has been demonstrated that rhoptry proteins play an important role in binding to erythrocyte surface receptors, among which is the PfRhopH3 protein, which triggers important immune responses in patients from endemic regions. It has also been reported that anti-RhopH3 antibodies inhibit in vitro invasion of erythrocytes, further supporting its direct involvement in erythrocyte invasion processes. In this study, PfRhopH3 consecutive peptides were synthesized and tested in erythrocyte binding assays for identifying those regions mediating binding to erythrocytes. Fourteen PfRhopH3 peptides presenting high specific binding activity were found, whose bindings were saturable and presented nanomolar dissociation constants. These high-activity binding peptides (HABPs) were characterized by having alpha-helical structural elements, as determined by circular dichroism, and having receptors of a possible sialic acid-dependent and/or glycoprotein-dependent nature, as evidenced in enzyme-treated erythrocyte binding assays and further corroborated by cross-linking assay results. Furthermore, these HABPs inhibited merozoite in vitro invasion of normal erythrocytes at 200 microM by up to 60% and 90%, suggesting that some RhopH3 protein regions are involved in the P. falciparum erythrocyte invasion.
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Vincensini L, Fall G, Berry L, Blisnick T, Braun Breton C. The RhopH complex is transferred to the host cell cytoplasm following red blood cell invasion by Plasmodium falciparum. Mol Biochem Parasitol 2008; 160:81-9. [PMID: 18508137 DOI: 10.1016/j.molbiopara.2008.04.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Revised: 04/03/2008] [Accepted: 04/04/2008] [Indexed: 11/29/2022]
Abstract
The high-molecular mass rhoptry protein complex (PfRhopH), which comprises three distinct gene products, RhopH1, RhopH2, and RhopH3, is known to be secreted and transferred to the parasitophorous vacuole membrane upon invasion of a red blood cell by the malaria parasite Plasmodium falciparum. Here we show that the merozoite-acquired RhopH complex is also transferred to defined domains of the red blood cell cytoplasm, and possibly transiently associated with Maurer's clefts. This is the first report of trafficking in the host cell cytoplasm for P. falciparum rhoptry proteins secreted upon red blood cell invasion. Based on its newly identified sub-cellular location and the phenotype of RhopH1 mutants, we propose that the RhopH complex participate in the assembly of the cytoadherence complex.
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Affiliation(s)
- Laetitia Vincensini
- Unité de Biologie des Interactions Hôte-Parasite, CNRS URA 2581 Institut Pasteur, 25-28 Rue du Dr Roux, Paris, France
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Characterization of a conserved rhoptry-associated leucine zipper-like protein in the malaria parasite Plasmodium falciparum. Infect Immun 2008; 76:879-87. [PMID: 18174339 DOI: 10.1128/iai.00144-07] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
One of the key processes in the pathobiology of the malaria parasite is the invasion and subsequent modification of the human erythrocyte. In this complex process, an unknown number of parasite proteins are involved, some of which are leading vaccine candidates. The majority of the proteins that play pivotal roles in invasion are either stored in the apical secretory organelles or located on the surface of the merozoite, the invasive stage of the parasite. Using transcriptional and structural features of these known proteins, we performed a genomewide search that identified 49 hypothetical proteins with a high probability of being located on the surface of the merozoite or in the secretory organelles. Of these candidates, we characterized a novel leucine zipper-like protein in Plasmodium falciparum that is conserved in Plasmodium spp. This protein is expressed in late blood stages and localizes to the rhoptries of the parasite. We demonstrate that this Plasmodium sp.-specific protein has a high degree of conservation within field isolates and that it is refractory to gene knockout attempts and thus might play an important role in invasion.
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36
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Kats LM, Cooke BM, Coppel RL, Black CG. Protein Trafficking to Apical Organelles of Malaria Parasites - Building an Invasion Machine. Traffic 2007; 9:176-86. [PMID: 18047549 DOI: 10.1111/j.1600-0854.2007.00681.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Lev M Kats
- NHMRC Program in Malaria, Department of Microbiology, Monash University, Victoria 3800, Australia
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37
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Mononeme: a new secretory organelle in Plasmodium falciparum merozoites identified by localization of rhomboid-1 protease. Proc Natl Acad Sci U S A 2007; 104:20043-8. [PMID: 18048320 DOI: 10.1073/pnas.0709999104] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Compartmentalization of proteins into subcellular organelles in eukaryotic cells is a fundamental mechanism of regulating complex cellular functions. Many proteins of Plasmodium falciparum merozoites involved in invasion are compartmentalized into apical organelles. We have identified a new merozoite organelle that contains P. falciparum rhomboid-1 (PfROM1), a protease that cleaves the transmembrane regions of proteins involved in invasion. By immunoconfocal microscopy, PfROM1 was localized to a single, thread-like structure on one side of the merozoites that appears to be in close proximity to the subpellicular microtubules. PfROM1 was not found associated with micronemes, rhoptries, or dense granules, the three identified secretory organelles of invasion. Release of merozoites from schizonts resulted in the movement of PfROM1 from the lateral asymmetric localization to the merozoite apical pole and the posterior pole. We have named this single thread-like organelle in merozoites, the mononeme.
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38
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Iriko H, Kaneko O, Otsuki H, Tsuboi T, Su XZ, Tanabe K, Torii M. Diversity and evolution of the rhoph1/clag multigene family of Plasmodium falciparum. Mol Biochem Parasitol 2007; 158:11-21. [PMID: 18155305 DOI: 10.1016/j.molbiopara.2007.11.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Revised: 11/05/2007] [Accepted: 11/06/2007] [Indexed: 11/19/2022]
Abstract
A complex of high-molecular-mass proteins (PfRhopH) of the human malaria parasite Plasmodium falciparum induces host protective immunity and therefore is a candidate for vaccine development. Understanding the level of polymorphism and the evolutionary processes is important for advancements in both vaccine design and knowledge of the evolution of cell invasion in this parasite. In the present study, we sequenced the entire open reading frames of seven genes encoding the proteins of the PfRhopH complex (rhoph2, rhoph3, and five rhoph1/clag gene paralogs). We found that four rhoph1/clag genes (clag2, 3.1, 3.2, and 8) were highly polymorphic. Amino acid substitutions and indels are predominantly clustered around amino acid positions 1000-1200 of these four rhoph1/clag genes. An excess of nonsynonymous substitutions over synonymous substitutions was detected for clag8 and 9, indicating positive selection. The McDonald-Kreitman test with a Plasmodium reichenowi orthologous sequence also supports positive selection on clag8. Based on the ratio of interspecific genetic distance to intraspecific distance, the time to the most recent common ancestor of the clag2 and 8 polymorphisms was estimated to be 1.89 and 0.87 million years ago, respectively, assuming divergence of P. falciparum and P. reichenowi 6 million years ago. In addition to a copy number polymorphism, gene conversion events were detected for the rhoph1/clag genes on chromosome 3, which likely play a role in increasing the diversity of each locus. Our results indicate that a high diversity of the PfRhopH1/Clag multigene family is maintained by diversifying selection forces over a considerably long period.
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Affiliation(s)
- Hideyuki Iriko
- Department of Molecular Parasitology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
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39
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Kaneko O. Erythrocyte invasion: vocabulary and grammar of the Plasmodium rhoptry. Parasitol Int 2007; 56:255-62. [PMID: 17596999 DOI: 10.1016/j.parint.2007.05.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 05/21/2007] [Accepted: 05/22/2007] [Indexed: 11/29/2022]
Abstract
Malaria is a dangerous infectious disease caused by obligate intracellular protozoan Plasmodium parasites. In the vertebrate host, erythrocyte recognition and establishment of a nascent parasitophorous vacuole are essential processes, and are largely achieved using molecules located in the microorganelles of the invasive-stage parasites. Recent proteome analyses of the phylogenetically related Toxoplasma parasite have provided protein catalogs for these microorganelles, which can now be used to identify orthologous proteins in the Plasmodium genome. Of importance is the formation of a complex between the proteins secreted from the rhoptry neck portion (RONs) and micronemes (AMA1), which localize at the moving junction during parasite invagination into the host cell. In this article I review the largely unexplored paradigm of the malaria merozoite rhoptry, focusing on the high molecular weight rhoptry protein complex (the RhopH complex), and speculate on its grammar during invasion.
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Affiliation(s)
- Osamu Kaneko
- Department of Molecular Parasitology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan.
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40
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Cai Q, Peng G, Bu L, Lin Y, Zhang L, Lustigmen S, Wang H. Immunogenicity and in vitro protective efficacy of a polyepitope Plasmodium falciparum candidate vaccine constructed by epitope shuffling. Vaccine 2007; 25:5155-65. [PMID: 17548134 DOI: 10.1016/j.vaccine.2007.04.085] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2006] [Revised: 04/27/2007] [Accepted: 04/29/2007] [Indexed: 11/22/2022]
Abstract
A polyepitope chimeric antigen incorporating multiple protective and conservative epitopes from multiple antigens of Plasmodium falciparum has been considered to be more effective in inducing multiple layers of immunity against malaria than a single stage- or single antigen-based vaccine. By modifying the molecular breeding approach to epitope shuffling, we have constructed a polyepitope chimeric gene that encodes 11 B-cell and T-cell proliferative epitope peptides derived from eight key antigens mostly in the blood stage of Plasmodium falciparum. A 35-kDa antigen encoded by this gene, named Malaria RCAg-1, was purified from an E. coli expression system. Immunization of rabbits and mice with the purified protein in the presence of Freund's adjuvant strongly generated long-lasting antibody responses that recognized the corresponding individual epitope peptide in this vaccine as well as blood stage parasites. CD4(+) T-cell responses were also elicited as shown by the enhancement of T-cell proliferation, IFN-gamma and IL-4 level. In vitro assay of protection revealed that vaccine-elicited antibodies could efficiently inhibit the growth of blood-stage parasites. Additionally, the chimeric antigen was recognized by human serum specimens from malaria patients and individuals living in the endemic area. Our studies indicate the potential of M.RCAg-1 recombinant protein as malaria candidate vaccines as well as the rationale of the epitope shuffling technology applied in designing malaria vaccines.
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Affiliation(s)
- Qiliang Cai
- Department of Microbiology and Parasitology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China
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41
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Mongui A, Perez-Leal O, Rojas-Caraballo J, Angel DI, Cortes J, Patarroyo MA. Identifying and characterising the Plasmodium falciparum RhopH3 Plasmodium vivax homologue. Biochem Biophys Res Commun 2007; 358:861-6. [PMID: 17511961 DOI: 10.1016/j.bbrc.2007.05.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Accepted: 05/02/2007] [Indexed: 11/29/2022]
Abstract
Four Plasmodium species cause malaria in humans, Plasmodium falciparum being the most widely studied to date. All Plasmodium species have paired club-shaped organelles towards their apical extreme named rhoptries that contain many lipids and proteins which are released during target cell invasion. P. falciparum RhopH3 is a rhoptry protein triggering important immune responses in patients from endemic regions. It has also been shown that anti-RhopH3 antibodies inhibit in vitro invasion of erythrocytes. Recent immunisation studies in mice with the Plasmodium yoelii and Plasmodium berghei RhopH3 P. falciparum homologue proteins found that they are able to induce protection in murine models. This study described identifying and characterising RhopH3 protein in Plasmodium vivax; it is encoded by a seven exon gene and expressed during the parasite's asexual stage. PvRhopH3 has similar processing to its homologue in P. falciparum and presents a cellular immunolocalisation pattern characteristic of rhoptry proteins.
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Affiliation(s)
- Alvaro Mongui
- Molecular Biology Department, Fundacion Instituto de Inmunologia de Colombia, Carrera 50#26-00, Bogota, Colombia
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42
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Sanders PR, Cantin GT, Greenbaum DC, Gilson PR, Nebl T, Moritz RL, Yates JR, Hodder AN, Crabb BS. Identification of protein complexes in detergent-resistant membranes of Plasmodium falciparum schizonts. Mol Biochem Parasitol 2007; 154:148-57. [PMID: 17553576 DOI: 10.1016/j.molbiopara.2007.04.013] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 04/19/2007] [Accepted: 04/20/2007] [Indexed: 11/26/2022]
Abstract
Merozoite surface proteins of the human malaria parasite Plasmodium falciparum are involved in initial contact with target erythrocytes, a process that begins a cascade of events required for successful invasion of these cells. In order to identify complexes that may play a role in invasion we purified detergent-resistant membranes (DRMs), known to be enriched in merozoite surface proteins, and used blue native-polyacrylamide gel electrophoresis (BN-PAGE) to isolate high molecular weight complexes for identification by mass spectrometry. Sixty-two proteins were detected and these mostly belonged to expected DRM proteins classes including GPI-anchored, multi-membrane spanning and rhoptry proteins. Proteins from seven known complexes were identified including MSP-1/7, the low (RAP1/2 and RAP1/3), and high (RhopH1/H2/H3) molecular weight rhoptry complexes, and the invasion motor complex (GAP45/GAP50/myosinA). Remarkably, a large proportion of identified spectra were derived from only 4 proteins: the GPI-anchored proteins MSP-1 and Pf92, the putative GPI-anchored protein Pf113 and RAP-1, the core component of the two RAP complexes. Each of these proteins predominated in high molecular weight species suggesting their aggregation in much larger complexes than anticipated. To demonstrate that the procedure had isolated novel complexes we focussed on MSP-1, which predominated as a distinct species at approximately 500 kDa by BN-PAGE, approximately twice its expected size. Chemical cross-linking supports the existence of a stable MSP-1 oligomer of approximately 500 kDa, probably comprising a highly stable homodimeric species. Our observations also suggests that oligomerization of MSP-1 is likely to occur outside the C-terminal epidermal growth factor (EGF)-like domains. Confirmation of MSP-1 oligomerization, together with the isolation of a number of known complexes by BN-PAGE, makes it highly likely that novel interactions occur amongst members of this proteome.
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Affiliation(s)
- Paul R Sanders
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, Vic 3050, Australia
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43
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Ghoneim A, Kaneko O, Tsuboi T, Torii M. The Plasmodium falciparum RhopH2 promoter and first 24 amino acids are sufficient to target proteins to the rhoptries. Parasitol Int 2007; 56:31-43. [PMID: 17175193 DOI: 10.1016/j.parint.2006.11.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Revised: 10/29/2006] [Accepted: 11/01/2006] [Indexed: 10/23/2022]
Abstract
The rhoptry secretory organelles of the malaria parasite, Plasmodium falciparum, contain a RhopH complex, which is composed of the proteins RhopH1, RhopH2, and RhopH3. RhopH1 is encoded by the rhoph1/clag multi-gene family, whereas RhopH2 and RhopH3 are encoded by single-copy genes. The precise function of the RhopH complex has not been identified, but it has been shown that the component proteins are involved in erythrocyte binding and perhaps participate in the formation of the parasitophorous vacuolar membrane. In this study, we have isolated pfrhoph2 promoter plus the signal peptide encoding sequence and generated transgene expression constructs to evaluate a trafficking and the RhopH complex formation in transgenic P. falciparum parasite lines. Interestingly, we found that the N-terminal 24 amino acids of RhopH2, including signal peptide sequence, were sufficient to target GFP to the rhoptries under the rhoph2 promoter. Because it was previously shown that the timing of the expression alone could not target proteins to the apical organelles, this targeting is likely mediated via a unique mechanism that is dependent on N-terminal 24 amino acids of RhopH2 early in the secretory pathway. The N-terminal one third of Clag3.1, which contains a distinct conserved domain with Toxoplasma gondii RON2, can not associate the RhopH complex as a GFP chimera, but a c-Myc-Clag3.1 chimera lacking the C-terminus successfully associates the RhopH complex indicating that cooperation of middle region is likely required but the C-terminus is not necessary.
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Affiliation(s)
- Ahmed Ghoneim
- Department of Molecular Parasitology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
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44
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Abstract
Secretory processes play an important role on the biology and life cycles of parasitic protozoa. This review focus on basic aspects, from a cell biology perspective, of the secretion of (a) micronemes, rhoptries and dense granules in members of the Apicomplexa group, where these organelles are involved in the process of protozoan penetration into the host cell, survival within the parasitophorous vacuole and subsequent egress from the host cell, (b) the Maurer's cleft in Plasmodium, a structure involved in the secretion of proteins synthesized by the intravacuolar parasite and transported through vesicles to the erythrocyte surface, (c) the secretion of macromolecules into the flagellar pocket of trypanosomatids, and (d) the secretion of proteins which make the cyst wall of Giardia and Entamoeba, with the formation of encystation vesicles.
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Affiliation(s)
- Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Ilha do Fundão, 21949-900 Rio de Janeiro, RJ, Brazil.
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45
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Yan HHN, Cheng CY. Laminin alpha 3 forms a complex with beta3 and gamma3 chains that serves as the ligand for alpha 6beta1-integrin at the apical ectoplasmic specialization in adult rat testes. J Biol Chem 2006; 281:17286-17303. [PMID: 16608848 DOI: 10.1074/jbc.m513218200] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Apical ectoplasmic specialization (ES) is a testis-specific hybrid cell/cell actin-based adherens junction and cell/matrix focal contact anchoring junction type restricted to the interface between Sertoli cells and developing spermatids. Recent studies have shown that laminin gamma3, restricted to elongating spermatids, is a putative binding partner of alpha 6beta 1-integrin localized in Sertoli cells at the apical ES. However, the identity of the alpha and beta chains, which constitute a functional laminin ligand with the gamma3 chain at the apical ES, is not known. Using reverse transcription-PCR and immunoblotting to survey all laminin chains in cells of the seminiferous epithelium, it was noted that alpha 2, alpha 3, beta1, beta2, beta3, and gamma3 chains were found in germ cells, whereas alpha 1, alpha 2, alpha 4, alpha 5, beta1, beta2, gamma1, gamma2, and gamma3 chains were found in Sertoli cells, implying that alpha 3 and beta3 are the plausible laminin chains restricted to germ cells that may be the bona fide partners of gamma3. To verify this postulate, recombinant proteins based on domain G of alpha 3 and domain I of beta3 and gamma3 chains were produced and used to obtain the corresponding specific polyclonal antibodies. Additional studies have demonstrated that the laminin alpha 3, beta3, and gamma3 chains indeed are restricted to germ cells at the apical ES, co-localizing with each other and with beta1-integrin. Furthermore, co-immunoprecipitation studies have confirmed the interactions among laminin alpha 3, beta3, and gamma3, as well as beta1-integrin. When the functional laminin ligand at the apical ES was disrupted via blocking antibodies, such as using anti-laminin alpha 3 or gamma3 IgG, this treatment perturbed adhesion between Sertoli and germ cells (mostly spermatids), leading to germ cell loss from the epithelium. More important, a transient disruption of the blood-testis barrier was also detected.
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Affiliation(s)
- Helen H N Yan
- Center for Biomedical Research, Population Council, New York, New York 10021
| | - C Yan Cheng
- Center for Biomedical Research, Population Council, New York, New York 10021.
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46
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Wang T, Fujioka H, Drazba JA, Sam-Yellowe TY. Rhop-3 protein conservation among Plasmodium species and induced protection against lethal P. yoelii and P. berghei challenge. Parasitol Res 2006; 99:238-52. [PMID: 16541261 DOI: 10.1007/s00436-006-0136-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2005] [Accepted: 11/28/2005] [Indexed: 11/29/2022]
Abstract
In the present study, Rhop-3 polymorphism among Plasmodium falciparum field and laboratory isolates and among rodent Plasmodium species was investigated and identified. The Rhop-3 gene was found in all Plasmodium species so far tested. The overall structure of the Rhop-3 protein was found conserved among P. falciparum, Plasmodium yoelii, and Plasmodium berghei. However, it was more conserved among rodent Plasmodium species than between P. falciparum and Plasmodium vivax. The most conserved regions of Rhop-3 are the second half of exon 6 (amino acid #548 to #665) and the beginning of exon 3 (amino acid #59 to #210). Recombinant C-terminal partial and full-length Rhop-3 proteins of P. yoelii and P. berghei were expressed in Escherichia coli and purified. Immunization-challenge experiments in mice using recombinant Rhop-3 proteins led to a delay in parasite development and protected mice from a homologous lethal challenge infection. In a group of eight outbred Carworth Farm White (CFW) mice immunized with P. yoelii C-terminal recombinant His-Y1412 protein, three mice (37.5%) were protected from a lethal P. yoelii challenge. In BALB/cJ mice one mouse (20%) survived the infection. Immunization of mice with P. berghei recombinant full-length Rhop-3 protein in BALB/cJ mice led to a 40% survival from lethal P. berghei challenge. CFW mice immunized with P. berghei recombinant full-length Rhop-3 protein showed a significant delay in parasite development with a heterologous P. yoelii challenge. The Rhop-3 protein is a promising candidate for an asexual stage malaria vaccine.
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Affiliation(s)
- Tongmin Wang
- Department of Biological, Geological and Environmental Sciences, Cleveland State University, Cleveland, OH, USA.
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47
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Kaneko O, Yim Lim BYS, Iriko H, Ling IT, Otsuki H, Grainger M, Tsuboi T, Adams JH, Mattei D, Holder AA, Torii M. Apical expression of three RhopH1/Clag proteins as components of the Plasmodium falciparum RhopH complex. Mol Biochem Parasitol 2005; 143:20-8. [PMID: 15953647 DOI: 10.1016/j.molbiopara.2005.05.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Revised: 04/28/2005] [Accepted: 05/02/2005] [Indexed: 11/26/2022]
Abstract
The Plasmodium falciparum high molecular mass rhoptry protein ('PfRhopH') complex is important for parasite growth and comprises three distinct gene products: RhopH1, RhopH2 and RhopH3. We have previously shown that P. falciparum RhopH1 is encoded by either PFC0110w (clag3.2) or PFC0120w (clag3.1), members of the previously-named clag (cytoadherence-linked asexual gene) multigene family. In this report, we have further characterized rhoph1/clag members in terms of gene structure, transcription and protein expression. The cDNA sequences for all five rhoph1/clag members were determined, confirming previous in silico predictions of intron-exon boundaries. All member genes were transcribed in HB3 and 3D7 parasite lines, but clag3.2 was not transcribed in Dd2 parasites. The peak abundance of transcripts for all genes was observed during the late schizont stage. Antisera specific to Clag2 and Clag3.1 localized these proteins to the apical end of merozoites in segmented schizonts, and both proteins are found to be components of the PfRhopH complex. PfRhopH complex that was immunoprecipitated with anti-Clag9 antibody contained neither Clag2 nor Clag3.1, thereby suggesting that PfRhopH complexes contain only individual rhoph1/clag gene products. Since the PfRhopH complex binds the erythrocyte surface, and RhopH2 and RhopH3 are encoded by single copy genes, the RhopH1/Clag proteins may serve to confer some degree of specificity to the roles of the individual complexes.
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Affiliation(s)
- Osamu Kaneko
- Department of Molecular Parasitology, Ehime University School of Medicine, Toon, Shigenobu-cho, Ehime 791-0295, Japan.
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48
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Trenholme KR, Boutlis CS, Kuns R, Lagog M, Bockarie MJ, Gatton ML, Kemp DJ, Good MF, Anstey NM, Gardiner DL. Antibody reactivity to linear epitopes of Plasmodium falciparum cytoadherence-linked asexual gene 9 in asymptomatic children and adults from papua new Guinea. Am J Trop Med Hyg 2005; 72:708-13. [PMID: 15964954 PMCID: PMC2532502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
The cytoadherence-linked asexual gene 9 (clag 9) of Plasmodium falciparum has been implicated in the cytoadherence of infected erythrocytes. To determine the immunogenicity of the clag 9 gene product (CLAG 9 protein) in humans, we measured antibody responses to 11 synthetic CLAG 9 peptides in a group of 177 asymptomatic children and adults subject to intense malaria exposure in Madang, Papua New Guinea. The CLAG 9 peptides were immunogenic in adults and children. Antibody responses to peptides 4 and 10 were high across all age groups and detectable in a majority of children less than five years of age. While CLAG 9 peptides are immunogenic in humans, longitudinal studies will be required to determine the longevity of antibody responses to CLAG 9 and their role in protection from disease.
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Affiliation(s)
- Katharine R Trenholme
- Division of Infectious Diseases and Immunology, The Australian Centre for International and Tropical Health and Nutrition, The Queensland Institute of Medical Research, Brisbane, Queensland, Australia.
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49
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Rungruang T, Kaneko O, Murakami Y, Tsuboi T, Hamamoto H, Akimitsu N, Sekimizu K, Kinoshita T, Torii M. Erythrocyte surface glycosylphosphatidyl inositol anchored receptor for the malaria parasite. Mol Biochem Parasitol 2005; 140:13-21. [PMID: 15694483 DOI: 10.1016/j.molbiopara.2004.11.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2004] [Revised: 11/03/2004] [Accepted: 11/04/2004] [Indexed: 12/01/2022]
Abstract
Parasitophorous vacuole formation is a critical step for the successful invasion of host erythrocytes by the malaria parasite. Rhoptry proteins are believed to have essential roles in vacuole formation, although their biological roles are poorly understood. To understand the molecular interactions between parasite rhoptry proteins and the erythrocyte during invasion, we have characterized the binding specificity of the high molecular mass rhoptry protein (RhopH) complex to erythrocytes using the rodent malaria parasite, Plasmodium yoelii. RhopH complex binding to erythrocytes was species-specific, observed with mouse but not rabbit or human erythrocytes. Binding is abolished following treatment of erythrocytes with trypsin or chymotrypsin. Because host cell cholesterol-rich membrane domains are recruited into the nascent parasitophorous vacuole, we evaluated a possible role of RhopH complex binding to the cholesterol-rich membrane domain-associated glycosylphosphatidyl inositol (GPI)-anchored protein. Using chimeric mice harboring GPI-deficient erythrocytes, RhopH complex binding to GPI-deficient mouse erythrocytes was undetectable, indicating involvement of GPI-anchored protein in PyRhopH complex binding. Furthermore, a significant reduction of P. yoelii parasite infection of GPI-deficient erythrocytes was observed in vivo, probably due to inefficient invasion. We conclude that the major erythrocyte receptor for PyRhopH complex is a protein attached to the erythrocyte surface via GPI-anchor and that GPI-deficient erythrocytes are resistant to P. yoelii invasion.
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Affiliation(s)
- Thanaporn Rungruang
- Department of Molecular Parasitology, Ehime University School of Medicine, Toon, Ehime 791-0295, Japan
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Kim JY, Yokoyama N, Kumar S, Inoue N, Inaba M, Fujisaki K, Sugimoto C. Identification of a piroplasm protein of Theileria orientalis that binds to bovine erythrocyte band 3. Mol Biochem Parasitol 2004; 137:193-200. [PMID: 15383289 DOI: 10.1016/j.molbiopara.2004.05.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Revised: 05/17/2004] [Accepted: 05/17/2004] [Indexed: 11/20/2022]
Abstract
Theileria orientalis infects cattle and causes various disease symptoms, including anaemia and icterus. The erythrocytic stages are responsible for these symptoms but the molecular events involved in these stages have not yet been fully elucidated. In this study, we identified a T. orientalis cDNA that encodes a polypeptide related to identity to the microneme-rhoptry protein of Theileria parva. Analysis of its recombinant product (ToMRP) by indirect fluorescent-antibody test revealed that it is specifically expressed at the early erythrocytic stage after invasion. This expression disappears during the intermediate stages of intra-erythrocytic development. Its expression then reappears at the late stages after the parasite has divided by binary fission into diad or tetrad forms and before these forms are released from the host erythrocyte. In vitro erythrocyte binding assays showed that ToMRP associates with the Triton X-insoluble fraction of erythrocytes membrane but not with intact erythrocytes. Cosedimentation and Western blot analyses revealed that ToMRP binds to band 3, a membrane component of bovine erythrocytes. These observations suggest that ToMRP may be involved in the parasite's egress from and/or invasion into the host erythrocytes by interacting with a protein in the membrane skeleton of the erythrocyte and thereby modifying the structure and function of the cell.
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Affiliation(s)
- Jung-Yeon Kim
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
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