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Mitra P, Deshmukh AS. Proteostasis is a key driver of the pathogenesis in Apicomplexa. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119824. [PMID: 39168412 DOI: 10.1016/j.bbamcr.2024.119824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 08/08/2024] [Accepted: 08/12/2024] [Indexed: 08/23/2024]
Abstract
Proteostasis, including protein folding mediated by molecular chaperones, protein degradation, and stress response pathways in organelles like ER (unfolded protein response: UPR), are responsible for cellular protein quality control. This is essential for cell survival as it regulates and reprograms cellular processes. Here, we underscore the role of the proteostasis pathway in Apicomplexan parasites with respect to their well-characterized roles as well as potential roles in many parasite functions, including survival, multiplication, persistence, and emerging drug resistance. In addition to the diverse physiological importance of proteostasis in Apicomplexa, we assess the potential of the pathway's components as chemotherapeutic targets.
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Affiliation(s)
- Pallabi Mitra
- BRIC-Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.
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2
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Sattler JM, Keiber L, Abdelrahim A, Zheng X, Jäcklin M, Zechel L, Moreau CA, Steinbrück S, Fischer M, Janse CJ, Hoffmann A, Hentzschel F, Frischknecht F. Experimental vaccination by single dose sporozoite injection of blood-stage attenuated malaria parasites. EMBO Mol Med 2024; 16:2060-2079. [PMID: 39103697 PMCID: PMC11392930 DOI: 10.1038/s44321-024-00101-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/28/2024] [Accepted: 07/02/2024] [Indexed: 08/07/2024] Open
Abstract
Malaria vaccination approaches using live Plasmodium parasites are currently explored, with either attenuated mosquito-derived sporozoites or attenuated blood-stage parasites. Both approaches would profit from the availability of attenuated and avirulent parasites with a reduced blood-stage multiplication rate. Here we screened gene-deletion mutants of the rodent parasite P. berghei and the human parasite P. falciparum for slow growth. Furthermore, we tested the P. berghei mutants for avirulence and resolving blood-stage infections, while preserving sporozoite formation and liver infection. Targeting 51 genes yielded 18 P. berghei gene-deletion mutants with several mutants causing mild infections. Infections with the two most attenuated mutants either by blood stages or by sporozoites were cleared by the immune response. Immunization of mice led to protection from disease after challenge with wild-type sporozoites. Two of six generated P. falciparum gene-deletion mutants showed a slow growth rate. Slow-growing, avirulent P. falciparum mutants will constitute valuable tools to inform on the induction of immune responses and will aid in developing new as well as safeguarding existing attenuated parasite vaccines.
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Affiliation(s)
- Julia M Sattler
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg, Germany
| | - Lukas Keiber
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg, Germany
| | - Aiman Abdelrahim
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg, Germany
| | - Xinyu Zheng
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg, Germany
| | - Martin Jäcklin
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg, Germany
| | - Luisa Zechel
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg, Germany
| | - Catherine A Moreau
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany
| | - Smilla Steinbrück
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg, Germany
| | - Manuel Fischer
- Department of Neuroradiology, Heidelberg University Medical School, 69120, Heidelberg, Germany
| | - Chris J Janse
- Leiden Malaria Research Group, Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Angelika Hoffmann
- Department of Neuroradiology, Heidelberg University Medical School, 69120, Heidelberg, Germany
- Department of Neuroradiology, University Institute of Diagnostic and Interventional Neuroradiology, University Hospital Bern, Inselspital, University of Bern, 3010, Bern, Switzerland
| | - Franziska Hentzschel
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, 69120, Heidelberg, Germany.
- German Center for Infection Research, DZIF, Partner Site Heidelberg, Heidelberg, Germany.
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3
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Thiele PJ, Mela-Lopez R, Blandin SA, Klug D. Let it glow: genetically encoded fluorescent reporters in Plasmodium. Malar J 2024; 23:114. [PMID: 38643106 PMCID: PMC11032601 DOI: 10.1186/s12936-024-04936-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/06/2024] [Indexed: 04/22/2024] Open
Abstract
The use of fluorescent proteins (FPs) in Plasmodium parasites has been key to understand the biology of this obligate intracellular protozoon. FPs like the green fluorescent protein (GFP) enabled to explore protein localization, promoter activity as well as dynamic processes like protein export and endocytosis. Furthermore, FP biosensors have provided detailed information on physiological parameters at the subcellular level, and fluorescent reporter lines greatly extended the malariology toolbox. Still, in order to achieve optimal results, it is crucial to know exactly the properties of the FP of choice and the genetic scenario in which it will be used. This review highlights advantages and disadvantages of available landing sites and promoters that have been successfully applied for the ectopic expression of FPs in Plasmodium berghei and Plasmodium falciparum. Furthermore, the properties of newly developed FPs beyond DsRed and EGFP, in the visualization of cells and cellular structures as well as in the sensing of small molecules are discussed.
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Affiliation(s)
- Pia J Thiele
- Inserm, CNRS, Université de Strasbourg, UPR9022/U1257, Mosquito Immune Responses (MIR), IBMC, F-67000, Strasbourg, France
| | - Raquel Mela-Lopez
- Inserm, CNRS, Université de Strasbourg, UPR9022/U1257, Mosquito Immune Responses (MIR), IBMC, F-67000, Strasbourg, France
| | - Stéphanie A Blandin
- Inserm, CNRS, Université de Strasbourg, UPR9022/U1257, Mosquito Immune Responses (MIR), IBMC, F-67000, Strasbourg, France
| | - Dennis Klug
- Inserm, CNRS, Université de Strasbourg, UPR9022/U1257, Mosquito Immune Responses (MIR), IBMC, F-67000, Strasbourg, France.
- Institute of Physiology and Pathophysiology, Department of Molecular Cell Physiology, Philipps University Marburg, 35037, Marburg, Germany.
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4
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Desai SA. Novel Ion Channel Genes in Malaria Parasites. Genes (Basel) 2024; 15:296. [PMID: 38540355 PMCID: PMC10970509 DOI: 10.3390/genes15030296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 06/14/2024] Open
Abstract
Ion channels serve many cellular functions including ion homeostasis, volume regulation, signaling, nutrient acquisition, and developmental progression. Although the complex life cycles of malaria parasites necessitate ion and solute flux across membranes, the whole-genome sequencing of the human pathogen Plasmodium falciparum revealed remarkably few orthologs of known ion channel genes. Contrasting with this, biochemical studies have implicated the channel-mediated flux of ions and nutritive solutes across several membranes in infected erythrocytes. Here, I review advances in the cellular and molecular biology of ion channels in malaria parasites. These studies have implicated novel parasite genes in the formation of at least two ion channels, with additional ion channels likely present in various membranes and parasite stages. Computational approaches that rely on homology to known channel genes from higher organisms will not be very helpful in identifying the molecular determinants of these activities. Given their unusual properties, novel molecular and structural features, and essential roles in pathogen survival and development, parasite channels should be promising targets for therapy development.
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Affiliation(s)
- Sanjay A Desai
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
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5
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Fréville A, Ressurreição M, van Ooij C. Identification of a non-exported Plasmepsin V substrate that functions in the parasitophorous vacuole of malaria parasites. mBio 2024; 15:e0122323. [PMID: 38078758 PMCID: PMC10790765 DOI: 10.1128/mbio.01223-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 10/26/2023] [Indexed: 01/17/2024] Open
Abstract
IMPORTANCE In the manuscript, the authors investigate the role of the protease Plasmepsin V in the parasite-host interaction. Whereas processing by Plasmepsin V was previously thought to target a protein for export into the host cell, the authors now show that there are proteins cleaved by this protease that are not exported but instead function at the host-parasite interface. This changes the view of this protease, which turns out to have a much broader role than anticipated. The result shows that the protease may have a function much more similar to that of related organisms. The authors also investigate the requirements for protein export by analyzing exported and non-exported proteins and find commonalities between the proteins of each set that further our understanding of the requirements for protein export.
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Affiliation(s)
- Aline Fréville
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Margarida Ressurreição
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christiaan van Ooij
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
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6
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Pitman EL, Counihan NA, Modak JK, Chowdury M, Gilson PR, Webb CT, de Koning-Ward TF. Dissecting EXP2 sequence requirements for protein export in malaria parasites. Front Cell Infect Microbiol 2024; 13:1332146. [PMID: 38282616 PMCID: PMC10811066 DOI: 10.3389/fcimb.2023.1332146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 12/19/2023] [Indexed: 01/30/2024] Open
Abstract
Apicomplexan parasites that reside within a parasitophorous vacuole harbor a conserved pore-forming protein that enables small-molecule transfer across the parasitophorous vacuole membrane (PVM). In Plasmodium parasites that cause malaria, this nutrient pore is formed by EXP2 which can complement the function of GRA17, an orthologous protein in Toxoplasma gondii. EXP2, however, has an additional function in Plasmodium parasites, serving also as the pore-forming component of the protein export machinery PTEX. To examine how EXP2 can play this additional role, transgenes that encoded truncations of EXP2, GRA17, hybrid GRA17-EXP2, or EXP2 under the transcriptional control of different promoters were expressed in EXP2 knockdown parasites to determine which could complement EXP2 function. This revealed that EXP2 is a unique pore-forming protein, and its protein export role in P. falciparum cannot be complemented by T. gondii GRA17. This was despite the addition of the EXP2 assembly strand and part of the linker helix to GRA17, which are regions necessary for the interaction of EXP2 with the other core PTEX components. This indicates that the body region of EXP2 plays a critical role in PTEX assembly and/or that the absence of other T. gondii GRA proteins in P. falciparum leads to its reduced efficiency of insertion into the PVM and complementation potential. Altering the timing and abundance of EXP2 expression did not affect protein export but affected parasite viability, indicating that the unique transcriptional profile of EXP2 when compared to other PTEX components enables it to serve an additional role in nutrient exchange.
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Affiliation(s)
- Ethan L. Pitman
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Natalie A. Counihan
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Joyanta K. Modak
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Mrittika Chowdury
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Paul R. Gilson
- Burnet Institute, Melbourne, VIC, Australia
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC, Australia
| | - Chaille T. Webb
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia
- Centre to Impact AMR, Monash University, Clayton, VIC, Australia
| | - Tania F. de Koning-Ward
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
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7
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Accoti A, Damiani C, Nunzi E, Cappelli A, Iacomelli G, Monacchia G, Turco A, D’Alò F, Peirce MJ, Favia G, Spaccapelo R. Anopheline mosquito saliva contains bacteria that are transferred to a mammalian host through blood feeding. Front Microbiol 2023; 14:1157613. [PMID: 37533823 PMCID: PMC10392944 DOI: 10.3389/fmicb.2023.1157613] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 06/29/2023] [Indexed: 08/04/2023] Open
Abstract
Introduction Malaria transmission occurs when Plasmodium sporozoites are transferred from the salivary glands of anopheline mosquitoes to a human host through the injection of saliva. The need for better understanding, as well as novel modes of inhibiting, this key event in transmission has driven intense study of the protein and miRNA content of saliva. Until now the possibility that mosquito saliva may also contain bacteria has remained an open question despite the well documented presence of a rich microbiome in salivary glands. Methods Using both 16S rRNA sequencing and MALDI-TOF approaches, we characterized the composition of the saliva microbiome of An. gambiae and An. stephensi mosquitoes which respectively represent two of the most important vectors for the major malaria-causing parasites P. falciparum and P. vivax. Results To eliminate the possible detection of non-mosquito-derived bacteria, we used a transgenic, fluorescent strain of one of the identified bacteria, Serratiamarcescens, to infect mosquitoes and detect its presence in mosquito salivary glands as well as its transfer to, and colonization of, mammalian host tissues following a mosquito bite. We also showed that Plasmodium infection modified the mosquito microbiota, increasing the presence of Serratia while diminishing the presence of Elizabethkingia and that both P. berghei and Serratia were transferred to, and colonized mammalian tissues. Discussion These data thus document the presence of bacteria in mosquito saliva, their transfer to, and growth in a mammalian host as well as possible interactions with Plasmodium transmission. Together they raise the possible role of mosquitoes as vectors of bacterial infection and the utility of commensal mosquito bacteria for the development of transmission-blocking strategies within a mammalian host.
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Affiliation(s)
- Anastasia Accoti
- Department of Medicine and Surgery, CIRM Italian Malaria Network Perugia, Functional Genomic Center (C.U.R.Ge.F), University of Perugia, Perugia, Italy
| | - Claudia Damiani
- School of Biosciences and Veterinary Medicine, University of Camerino, CIRM Italian Malaria Network, Via Gentile III da Varano, Camerino, Italy
| | - Emilia Nunzi
- Department of Medicine and Surgery, CIRM Italian Malaria Network Perugia, Functional Genomic Center (C.U.R.Ge.F), University of Perugia, Perugia, Italy
| | - Alessia Cappelli
- School of Biosciences and Veterinary Medicine, University of Camerino, CIRM Italian Malaria Network, Via Gentile III da Varano, Camerino, Italy
| | - Gloria Iacomelli
- Department of Medicine and Surgery, CIRM Italian Malaria Network Perugia, Functional Genomic Center (C.U.R.Ge.F), University of Perugia, Perugia, Italy
| | - Giulia Monacchia
- Department of Medicine and Surgery, CIRM Italian Malaria Network Perugia, Functional Genomic Center (C.U.R.Ge.F), University of Perugia, Perugia, Italy
| | - Antonella Turco
- Department of Medicine and Surgery, CIRM Italian Malaria Network Perugia, Functional Genomic Center (C.U.R.Ge.F), University of Perugia, Perugia, Italy
| | - Francesco D’Alò
- Department of Medicine and Surgery, CIRM Italian Malaria Network Perugia, Functional Genomic Center (C.U.R.Ge.F), University of Perugia, Perugia, Italy
| | - Matthew J. Peirce
- Department of Medicine and Surgery, CIRM Italian Malaria Network Perugia, Functional Genomic Center (C.U.R.Ge.F), University of Perugia, Perugia, Italy
| | - Guido Favia
- School of Biosciences and Veterinary Medicine, University of Camerino, CIRM Italian Malaria Network, Via Gentile III da Varano, Camerino, Italy
| | - Roberta Spaccapelo
- Department of Medicine and Surgery, CIRM Italian Malaria Network Perugia, Functional Genomic Center (C.U.R.Ge.F), University of Perugia, Perugia, Italy
- Interuniversity Consortium for Biotechnology (C.I.B.), Trieste, Italy
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Jonsdottir TK, Elsworth B, Cobbold S, Gabriela M, Ploeger E, Parkyn Schneider M, Charnaud SC, Dans MG, McConville M, Bullen HE, Crabb BS, Gilson PR. PTEX helps efficiently traffic haemoglobinases to the food vacuole in Plasmodium falciparum. PLoS Pathog 2023; 19:e1011006. [PMID: 37523385 PMCID: PMC10414648 DOI: 10.1371/journal.ppat.1011006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 08/10/2023] [Accepted: 07/16/2023] [Indexed: 08/02/2023] Open
Abstract
A key element of Plasmodium biology and pathogenesis is the trafficking of ~10% of the parasite proteome into the host red blood cell (RBC) it infects. To cross the parasite-encasing parasitophorous vacuole membrane, exported proteins utilise a channel-forming protein complex termed the Plasmodium translocon of exported proteins (PTEX). PTEX is obligatory for parasite survival, both in vitro and in vivo, suggesting that at least some exported proteins have essential metabolic functions. However, to date only one essential PTEX-dependent process, the new permeability pathways, has been described. To identify other essential PTEX-dependant proteins/processes, we conditionally knocked down the expression of one of its core components, PTEX150, and examined which pathways were affected. Surprisingly, the food vacuole mediated process of haemoglobin (Hb) digestion was substantially perturbed by PTEX150 knockdown. Using a range of transgenic parasite lines and approaches, we show that two major Hb proteases; falcipain 2a and plasmepsin II, interact with PTEX core components, implicating the translocon in the trafficking of Hb proteases. We propose a model where these proteases are translocated into the PV via PTEX in order to reach the cytostome, located at the parasite periphery, prior to food vacuole entry. This work offers a second mechanistic explanation for why PTEX function is essential for growth of the parasite within its host RBC.
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Affiliation(s)
- Thorey K. Jonsdottir
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Brendan Elsworth
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Simon Cobbold
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Australia
| | - Mikha Gabriela
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- School of Medicine, Deakin University, Geelong, Australia
| | - Ellen Ploeger
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | | | - Sarah C. Charnaud
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Madeline G. Dans
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Malcolm McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Australia
| | - Hayley E. Bullen
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Brendan S. Crabb
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
- Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Paul R. Gilson
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
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Levray YS, Bana B, Tarr SJ, McLaughlin EJ, Rossi-Smith P, Waltho A, Charlton GH, Chiozzi RZ, Straton CR, Thalassinos K, Osborne AR. Formation of ER-lumenal intermediates during export of Plasmodium proteins containing transmembrane-like hydrophobic sequences. PLoS Pathog 2023; 19:e1011281. [PMID: 37000891 PMCID: PMC10096305 DOI: 10.1371/journal.ppat.1011281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 04/12/2023] [Accepted: 03/08/2023] [Indexed: 04/03/2023] Open
Abstract
During the blood stage of a malaria infection, malaria parasites export both soluble and membrane proteins into the erythrocytes in which they reside. Exported proteins are trafficked via the parasite endoplasmic reticulum and secretory pathway, before being exported across the parasitophorous vacuole membrane into the erythrocyte. Transport across the parasitophorous vacuole membrane requires protein unfolding, and in the case of membrane proteins, extraction from the parasite plasma membrane. We show that trafficking of the exported Plasmodium protein, Pf332, differs from that of canonical eukaryotic soluble-secreted and transmembrane proteins. Pf332 is initially ER-targeted by an internal hydrophobic sequence that unlike a signal peptide, is not proteolytically removed, and unlike a transmembrane segment, does not span the ER membrane. Rather, both termini of the hydrophobic sequence enter the ER-lumen and the ER-lumenal species is a productive intermediate for protein export. Furthermore, we show in intact cells, that two other exported membrane proteins, SBP1 and MAHRP2, assume a lumenal topology within the parasite secretory pathway. Although the addition of a C-terminal ER-retention sequence, recognised by the lumenal domain of the KDEL receptor, does not completely block export of SBP1 and MAHRP2, it does enhance their retention in the parasite ER. This indicates that a sub-population of each protein adopts an ER-lumenal state that is an intermediate in the export process. Overall, this suggests that although many exported proteins traverse the parasite secretory pathway as typical soluble or membrane proteins, some exported proteins that are ER-targeted by a transmembrane segment-like, internal, non-cleaved hydrophobic segment, do not integrate into the ER membrane, and form an ER-lumenal species that is a productive export intermediate. This represents a novel means, not seen in typical membrane proteins found in model systems, by which exported transmembrane-like proteins can be targeted and trafficked within the lumen of the secretory pathway.
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10
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Griffith MB, Pearce CS, Heaslip AT. Dense granule biogenesis, secretion, and function in Toxoplasma gondii. J Eukaryot Microbiol 2022; 69:e12904. [PMID: 35302693 PMCID: PMC9482668 DOI: 10.1111/jeu.12904] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite and the causative agent of Toxoplasmosis. A key to understanding and treating the disease lies with determining how the parasite can survive and replicate within cells of its host. Proteins released from specialized secretory vesicles, named the dense granules (DGs), have diverse functions that are critical for adapting the intracellular environment, and are thus key to survival and pathogenicity. In this review, we describe the current understanding and outstanding questions regarding dense granule biogenesis, trafficking, and regulation of secretion. In addition, we provide an overview of dense granule protein ("GRA") function upon secretion, with a focus on proteins that have recently been identified.
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Affiliation(s)
- Michael B Griffith
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Camille S Pearce
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Aoife T Heaslip
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
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11
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A member of the tryptophan-rich protein family is required for efficient sequestration of Plasmodium berghei schizonts. PLoS Pathog 2022; 18:e1010846. [PMID: 36126089 PMCID: PMC9524624 DOI: 10.1371/journal.ppat.1010846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/30/2022] [Accepted: 08/31/2022] [Indexed: 11/20/2022] Open
Abstract
Protein export and host membrane remodeling are crucial for multiple Plasmodium species to establish a niche in infected hosts. To better understand the contribution of these processes to successful parasite infection in vivo, we sought to find and characterize protein components of the intraerythrocytic Plasmodium berghei-induced membrane structures (IBIS) that form in the cytoplasm of infected erythrocytes. We identified proteins that immunoprecipitate with IBIS1, a signature member of the IBIS in P. berghei-infected erythrocytes. In parallel, we also report our data describing proteins that co-precipitate with the PTEX (Plasmodium translocon of exported proteins) component EXP2. To validate our findings, we examined the location of three candidate IBIS1-interactors that are conserved across multiple Plasmodium species, and we found they localized to IBIS in infected red blood cells and two further colocalized with IBIS1 in the liver-stage parasitophorous vacuole membrane. Successful gene deletion revealed that these two tryptophan-rich domain-containing proteins, termed here IPIS2 and IPIS3 (for intraerythrocytic Plasmodium-induced membrane structures), are required for efficient blood-stage growth. Erythrocytes infected with IPIS2-deficient schizonts in particular fail to bind CD36 as efficiently as wild-type P. berghei-infected cells and therefore fail to effectively sequester out of the circulating blood. Our findings support the idea that intra-erythrocytic membrane compartments are required across species for alterations of the host erythrocyte that facilitate interactions of infected cells with host tissues.
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12
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Bullen HE, Sanders PR, Dans MG, Jonsdottir TK, Riglar DT, Looker O, Palmer CS, Kouskousis B, Charnaud SC, Triglia T, Gabriela M, Schneider MP, Chan J, de Koning‐Ward TF, Baum J, Kazura JW, Beeson JG, Cowman AF, Gilson PR, Crabb BS. The
Plasmodium falciparum
parasitophorous vacuole protein
P113
interacts with the parasite protein export machinery and maintains normal vacuole architecture. Mol Microbiol 2022; 117:1245-1262. [PMID: 35403274 PMCID: PMC9544671 DOI: 10.1111/mmi.14904] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/31/2022] [Accepted: 04/05/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Hayley E. Bullen
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Microbiology and Immunology University of Melbourne Parkville Australia
| | | | - Madeline G. Dans
- Burnet Institute 85 Commercial Road Prahran Australia
- School of Medicine Deakin University Waurn Ponds Victoria Australia
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
| | - Thorey K. Jonsdottir
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Microbiology and Immunology University of Melbourne Parkville Australia
| | - David T. Riglar
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
- Department of Medical Biology University of Melbourne Parkville Australia
- Imperial College London Department of Infectious Diseases, South Kensington Campus, SW72AZ UK
| | - Oliver Looker
- Burnet Institute 85 Commercial Road Prahran Australia
| | - Catherine S. Palmer
- Burnet Institute 85 Commercial Road Prahran Australia
- Bio21, 30 Road Parkville Flemington Australia
| | | | - Sarah C. Charnaud
- Burnet Institute 85 Commercial Road Prahran Australia
- WHO Geneva Switzerland
| | - Tony Triglia
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
- Department of Medical Biology University of Melbourne Parkville Australia
| | - Mikha Gabriela
- Burnet Institute 85 Commercial Road Prahran Australia
- School of Medicine Deakin University Waurn Ponds Victoria Australia
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
| | | | - Jo‐Anne Chan
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Medicine University of Melbourne Parkville Victoria Australia
| | | | - Jake Baum
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
- Department of Medical Biology University of Melbourne Parkville Australia
- Imperial College London Department of Infectious Diseases, South Kensington Campus, SW72AZ UK
| | - James W. Kazura
- Centre for Global Health and Diseases Case Western Reserve University Cleveland Ohio USA
| | - James G. Beeson
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Medicine University of Melbourne Parkville Victoria Australia
- Department of Immunology, Central clinical school Monash University Melbourne Victoria Australia
| | - Alan F. Cowman
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
- Department of Medical Biology University of Melbourne Parkville Australia
| | - Paul R. Gilson
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Microbiology and Immunology University of Melbourne Parkville Australia
| | - Brendan S. Crabb
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Microbiology and Immunology University of Melbourne Parkville Australia
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13
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Kreutzfeld O, Grützke J, Ingmundson A, Müller K, Matuschewski K. Absence of PEXEL-Dependent Protein Export in Plasmodium Liver Stages Cannot Be Restored by Gain of the HSP101 Protein Translocon ATPase. Front Genet 2021; 12:742153. [PMID: 34956312 PMCID: PMC8693896 DOI: 10.3389/fgene.2021.742153] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/18/2021] [Indexed: 11/13/2022] Open
Abstract
Host cell remodeling is critical for successful Plasmodium replication inside erythrocytes and achieved by targeted export of parasite-encoded proteins. In contrast, during liver infection the malarial parasite appears to avoid protein export, perhaps to limit exposure of parasite antigens by infected liver cells. HSP101, the force-generating ATPase of the protein translocon of exported proteins (PTEX) is the only component that is switched off during early liver infection. Here, we generated transgenic Plasmodium berghei parasite lines that restore liver stage expression of HSP101. HSP101 expression in infected hepatocytes was achieved by swapping the endogenous promoter with the ptex150 promoter and by inserting an additional copy under the control of the elongation one alpha (ef1α) promoter. Both promoters drive constitutive and, hence, also pre-erythrocytic expression. Transgenic parasites were able to complete the life cycle, but failed to export PEXEL-proteins in early liver stages. Our results suggest that PTEX-dependent early liver stage export cannot be restored by addition of HSP101, indicative of alternative export complexes or other functions of the PTEX core complex during liver infection.
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Affiliation(s)
- Oriana Kreutzfeld
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.,Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Josephine Grützke
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.,Department of Biological Safety, Federal Institute for Risk Assessment, Berlin, Germany
| | - Alyssa Ingmundson
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Katja Müller
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Kai Matuschewski
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
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14
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Korbmacher F, Drepper B, Sanderson T, Martin P, Stach T, Maier AG, Matuschewski K, Matz JM. An apicoplast-resident folate transporter is essential for sporogony of malaria parasites. Cell Microbiol 2021; 23:e13266. [PMID: 32975363 PMCID: PMC7616068 DOI: 10.1111/cmi.13266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 08/14/2020] [Accepted: 09/18/2020] [Indexed: 11/30/2022]
Abstract
Malaria parasites are fast replicating unicellular organisms and require substantial amounts of folate for DNA synthesis. Despite the central role of this critical co-factor for parasite survival, only little is known about intraparasitic folate trafficking in Plasmodium. Here, we report on the expression, subcellular localisation and function of the parasite's folate transporter 2 (FT2) during life cycle progression in the murine malaria parasite Plasmodium berghei. Using live fluorescence microscopy of genetically engineered parasites, we demonstrate that FT2 localises to the apicoplast. In invasive P. berghei stages, a fraction of FT2 is also observed at the apical end. Upon genetic disruption of FT2, blood and liver infection, gametocyte production and mosquito colonisation remain unaltered. But in the Anopheles vector, FT2-deficient parasites develop inflated oocysts with unusual pulp formation consisting of numerous single-membrane vesicles, which ultimately fuse to form large cavities. Ultrastructural analysis suggests that this defect reflects aberrant sporoblast formation caused by abnormal vesicular traffic. Complete sporogony in FT2-deficient oocysts is very rare, and mutant sporozoites fail to establish hepatocyte infection, resulting in a complete block of parasite transmission. Our findings reveal a previously unrecognised organellar folate transporter that exerts critical roles for pathogen maturation in the arthropod vector.
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Affiliation(s)
- Francois Korbmacher
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Benjamin Drepper
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Theo Sanderson
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, UK
| | - Peer Martin
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Thomas Stach
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Alexander G. Maier
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Joachim M. Matz
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, UK
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15
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Edkins AL, Boshoff A. General Structural and Functional Features of Molecular Chaperones. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1340:11-73. [PMID: 34569020 DOI: 10.1007/978-3-030-78397-6_2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Molecular chaperones are a group of structurally diverse and highly conserved ubiquitous proteins. They play crucial roles in facilitating the correct folding of proteins in vivo by preventing protein aggregation or facilitating the appropriate folding and assembly of proteins. Heat shock proteins form the major class of molecular chaperones that are responsible for protein folding events in the cell. This is achieved by ATP-dependent (folding machines) or ATP-independent mechanisms (holders). Heat shock proteins are induced by a variety of stresses, besides heat shock. The large and varied heat shock protein class is categorised into several subfamilies based on their sizes in kDa namely, small Hsps (HSPB), J domain proteins (Hsp40/DNAJ), Hsp60 (HSPD/E; Chaperonins), Hsp70 (HSPA), Hsp90 (HSPC), and Hsp100. Heat shock proteins are localised to different compartments in the cell to carry out tasks specific to their environment. Most heat shock proteins form large oligomeric structures, and their functions are usually regulated by a variety of cochaperones and cofactors. Heat shock proteins do not function in isolation but are rather part of the chaperone network in the cell. The general structural and functional features of the major heat shock protein families are discussed, including their roles in human disease. Their function is particularly important in disease due to increased stress in the cell. Vector-borne parasites affecting human health encounter stress during transmission between invertebrate vectors and mammalian hosts. Members of the main classes of heat shock proteins are all represented in Plasmodium falciparum, the causative agent of cerebral malaria, and they play specific functions in differentiation, cytoprotection, signal transduction, and virulence.
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Affiliation(s)
- Adrienne Lesley Edkins
- Biomedical Biotechnology Research Unit (BioBRU), Department of Biochemistry and Microbiology, Rhodes University, Makhanda/Grahamstown, South Africa.
- Rhodes University, Makhanda/Grahamstown, South Africa.
| | - Aileen Boshoff
- Rhodes University, Makhanda/Grahamstown, South Africa.
- Biotechnology Innovation Centre, Rhodes University, Makhanda/Grahamstown, South Africa.
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16
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PV1 Protein from Plasmodium falciparum Exhibits Chaperone-Like Functions and Cooperates with Hsp100s. Int J Mol Sci 2020; 21:ijms21228616. [PMID: 33207549 PMCID: PMC7697860 DOI: 10.3390/ijms21228616] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 01/17/2023] Open
Abstract
Plasmodium falciparum parasitophorous vacuolar protein 1 (PfPV1), a protein unique to malaria parasites, is localized in the parasitophorous vacuolar (PV) and is essential for parasite growth. Previous studies suggested that PfPV1 cooperates with the Plasmodium translocon of exported proteins (PTEX) complex to export various proteins from the PV. However, the structure and function of PfPV1 have not been determined in detail. In this study, we undertook the expression, purification, and characterization of PfPV1. The tetramer appears to be the structural unit of PfPV1. The activity of PfPV1 appears to be similar to that of molecular chaperones, and it may interact with various proteins. PfPV1 could substitute CtHsp40 in the CtHsp104, CtHsp70, and CtHsp40 protein disaggregation systems. Based on these results, we propose a model in which PfPV1 captures various PV proteins and delivers them to PTEX through a specific interaction with HSP101.
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17
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Matz JM, Drepper B, Blum TB, van Genderen E, Burrell A, Martin P, Stach T, Collinson LM, Abrahams JP, Matuschewski K, Blackman MJ. A lipocalin mediates unidirectional heme biomineralization in malaria parasites. Proc Natl Acad Sci U S A 2020; 117:16546-16556. [PMID: 32601225 PMCID: PMC7368307 DOI: 10.1073/pnas.2001153117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
During blood-stage development, malaria parasites are challenged with the detoxification of enormous amounts of heme released during the proteolytic catabolism of erythrocytic hemoglobin. They tackle this problem by sequestering heme into bioinert crystals known as hemozoin. The mechanisms underlying this biomineralization process remain enigmatic. Here, we demonstrate that both rodent and human malaria parasite species secrete and internalize a lipocalin-like protein, PV5, to control heme crystallization. Transcriptional deregulation of PV5 in the rodent parasite Plasmodium berghei results in inordinate elongation of hemozoin crystals, while conditional PV5 inactivation in the human malaria agent Plasmodium falciparum causes excessive multidirectional crystal branching. Although hemoglobin processing remains unaffected, PV5-deficient parasites generate less hemozoin. Electron diffraction analysis indicates that despite the distinct changes in crystal morphology, neither the crystalline order nor unit cell of hemozoin are affected by impaired PV5 function. Deregulation of PV5 expression renders P. berghei hypersensitive to the antimalarial drugs artesunate, chloroquine, and atovaquone, resulting in accelerated parasite clearance following drug treatment in vivo. Together, our findings demonstrate the Plasmodium-tailored role of a lipocalin family member in hemozoin formation and underscore the heme biomineralization pathway as an attractive target for therapeutic exploitation.
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Affiliation(s)
- Joachim M Matz
- Malaria Biochemistry Laboratory, The Francis Crick Institute, NW1 1AT London, United Kingdom;
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Benjamin Drepper
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Thorsten B Blum
- Laboratory of Nanoscale Biology, Division of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Eric van Genderen
- Laboratory of Nanoscale Biology, Division of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Alana Burrell
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Peer Martin
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Thomas Stach
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Lucy M Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Jan Pieter Abrahams
- Laboratory of Nanoscale Biology, Division of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, 4051 Basel, Switzerland
- Institute of Biology, Leiden University, 2311 EZ Leiden, The Netherlands
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Michael J Blackman
- Malaria Biochemistry Laboratory, The Francis Crick Institute, NW1 1AT London, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, WC1E 7HT London, United Kingdom
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18
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Kenthirapalan S, Tran PN, Kooij TWA, Ridgway MC, Rauch M, Brown SHJ, Mitchell TW, Matuschewski K, Maier AG. Distinct adaptations of a gametocyte ABC transporter to murine and human Plasmodium parasites and its incompatibility in cross-species complementation. Int J Parasitol 2020; 50:511-522. [PMID: 32445722 DOI: 10.1016/j.ijpara.2020.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/25/2020] [Accepted: 03/27/2020] [Indexed: 11/18/2022]
Abstract
Parasites of the genus Plasmodium infect a wide range of mammalian hosts including humans, primates, bats and arboreal rodents. A hallmark of Plasmodium spp. is the very narrow host range, indicative of matching parasite-host coevolution. Accordingly, their respective genomes harbour many unique genes and gene families that typically encode proteins involved in host cell recognition and remodelling. Whether and to what extent conserved proteins that are shared across Plasmodium spp. also exert distinct species-specific roles remains largely untested. Here, we present detailed functional profiling of the female gametocyte-specific ATP-binding cassette transporter gABCG2 in the murine parasite Plasmodium berghei and compare our findings with data from the orthologous gene in the human parasite Plasmodium falciparum. We show that P. berghei gABCG2 is female-specific and continues to be expressed in zygotes and ookinetes. In contrast to a distinct localization to Iipid-rich gametocyte-specific spots as observed in P. falciparum, the murine malaria parasite homolog is found at the parasite plasma membrane. Plasmodium berghei lacking gABCG2 displays fast asexual blood-stage replication and increased proportions of female gametocytes, consistent with the corresponding P. falciparum knock-out phenotype. Strikingly, cross-species replacement of gABCG2 in either the murine or the human parasite did not restore normal growth rates. The lack of successful complementation despite high conservation across Plasmodium spp. is an indicator of distinct adaptations and tight parasite-host coevolution. Hence, incompatibility of conserved genes in closely related Plasmodium spp. might be more common than previously anticipated.
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Affiliation(s)
| | - Phuong N Tran
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Taco W A Kooij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Melanie C Ridgway
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Manuel Rauch
- Parasitology Unit, Max Planck Institute for Infection Biology, 10117 Berlin, Germany; Dept. of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Simon H J Brown
- School of Biological Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Todd W Mitchell
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia; School of Medicine, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Kai Matuschewski
- Parasitology Unit, Max Planck Institute for Infection Biology, 10117 Berlin, Germany; Dept. of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany.
| | - Alexander G Maier
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia.
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19
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Matz JM, Watanabe M, Falade M, Tohge T, Hoefgen R, Matuschewski K. Plasmodium Para-Aminobenzoate Synthesis and Salvage Resolve Avoidance of Folate Competition and Adaptation to Host Diet. Cell Rep 2020; 26:356-363.e4. [PMID: 30625318 DOI: 10.1016/j.celrep.2018.12.062] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 11/26/2018] [Accepted: 12/14/2018] [Indexed: 11/29/2022] Open
Abstract
Folate metabolism is essential for DNA synthesis and a validated drug target in fast-growing cell populations, including tumors and malaria parasites. Genome data suggest that Plasmodium has retained its capacity to generate folates de novo. However, the metabolic plasticity of folate uptake and biosynthesis by the malaria parasite remains unresolved. Here, we demonstrate that Plasmodium uses an aminodeoxychorismate synthase and an aminodeoxychorismate lyase to promote the biogenesis of the central folate precursor para-aminobenzoate (pABA) in the cytoplasm. We show that the parasite depends on de novo folate synthesis only when dietary intake of pABA by the mammalian host is restricted and that only pABA, rather than fully formed folate, is taken up efficiently. This adaptation, which readily adjusts infection to highly variable pABA levels in the mammalian diet, is specific to blood stages and may have evolved to avoid folate competition between the parasite and its host.
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Affiliation(s)
- Joachim Michael Matz
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany; Parasitology Unit, Max Planck Institute of Infection Biology, 10117 Berlin, Germany.
| | - Mutsumi Watanabe
- Department of Molecular Physiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; Nara Institute of Science and Technology, Graduate School of Biological Sciences, Plant Secondary Metabolism, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
| | | | - Takayuki Tohge
- Department of Molecular Physiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany; Nara Institute of Science and Technology, Graduate School of Biological Sciences, Plant Secondary Metabolism, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Rainer Hoefgen
- Department of Molecular Physiology, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany; Parasitology Unit, Max Planck Institute of Infection Biology, 10117 Berlin, Germany
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20
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The parasitophorous vacuole of the blood-stage malaria parasite. Nat Rev Microbiol 2020; 18:379-391. [PMID: 31980807 DOI: 10.1038/s41579-019-0321-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2019] [Indexed: 12/31/2022]
Abstract
The pathology of malaria is caused by infection of red blood cells with unicellular Plasmodium parasites. During blood-stage development, the parasite replicates within a membrane-bound parasitophorous vacuole. A central nexus for host-parasite interactions, this unique parasite shelter functions in nutrient acquisition, subcompartmentalization and the export of virulence factors, making its functional molecules attractive targets for the development of novel intervention strategies to combat the devastating impact of malaria. In this Review, we explore the origin, development, molecular composition and functions of the parasitophorous vacuole of Plasmodium blood stages. We also discuss the relevance of the malaria parasite's intravacuolar lifestyle for successful erythrocyte infection and provide perspectives for future research directions in parasitophorous vacuole biology.
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21
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Martin RE. The transportome of the malaria parasite. Biol Rev Camb Philos Soc 2019; 95:305-332. [PMID: 31701663 DOI: 10.1111/brv.12565] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 10/02/2019] [Accepted: 10/04/2019] [Indexed: 12/15/2022]
Abstract
Membrane transport proteins, also known as transporters, control the movement of ions, nutrients, metabolites, and waste products across the membranes of a cell and are central to its biology. Proteins of this type also serve as drug targets and are key players in the phenomenon of drug resistance. The malaria parasite has a relatively reduced transportome, with only approximately 2.5% of its genes encoding transporters. Even so, assigning functions and physiological roles to these proteins, and ascertaining their contributions to drug action and drug resistance, has been very challenging. This review presents a detailed critique and synthesis of the disruption phenotypes, protein subcellular localisations, protein functions (observed or predicted), and links to antimalarial drug resistance for each of the parasite's transporter genes. The breadth and depth of the gene disruption data are particularly impressive, with at least one phenotype determined in the parasite's asexual blood stage for each transporter gene, and multiple phenotypes available for 76% of the genes. Analysis of the curated data set revealed there to be relatively little redundancy in the Plasmodium transportome; almost two-thirds of the parasite's transporter genes are essential or required for normal growth in the asexual blood stage of the parasite, and this proportion increased to 78% when the disruption phenotypes available for the other parasite life stages were included in the analysis. These observations, together with the finding that 22% of the transportome is implicated in the parasite's resistance to existing antimalarials and/or drugs within the development pipeline, indicate that transporters are likely to serve, or are already serving, as drug targets. Integration of the different biological and bioinformatic data sets also enabled the selection of candidates for transport processes known to be essential for parasite survival, but for which the underlying proteins have thus far remained undiscovered. These include potential transporters of pantothenate, isoleucine, or isopentenyl diphosphate, as well as putative anion-selective channels that may serve as the pore component of the parasite's 'new permeation pathways'. Other novel insights into the parasite's biology included the identification of transporters for the potential development of antimalarial treatments, transmission-blocking drugs, prophylactics, and genetically attenuated vaccines. The syntheses presented herein set a foundation for elucidating the functions and physiological roles of key members of the Plasmodium transportome and, ultimately, to explore and realise their potential as therapeutic targets.
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Affiliation(s)
- Rowena E Martin
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
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22
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Matz JM, Goosmann C, Matuschewski K, Kooij TWA. An Unusual Prohibitin Regulates Malaria Parasite Mitochondrial Membrane Potential. Cell Rep 2019; 23:756-767. [PMID: 29669282 DOI: 10.1016/j.celrep.2018.03.088] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 02/16/2018] [Accepted: 03/20/2018] [Indexed: 11/26/2022] Open
Abstract
Proteins of the stomatin/prohibitin/flotillin/HfIK/C (SPFH) family are membrane-anchored and perform diverse cellular functions in different organelles. Here, we investigate the SPFH proteins of the murine malaria model parasite Plasmodium berghei, the conserved prohibitin 1, prohibitin 2, and stomatin-like protein and an unusual prohibitin-like protein (PHBL). The SPFH proteins localize to the parasite mitochondrion. While the conserved family members could not be deleted from the Plasmodium genome, PHBL was successfully ablated, resulting in impaired parasite fitness and attenuated virulence in the mammalian host. Strikingly, PHBL-deficient parasites fail to colonize the Anopheles vector because of complete arrest during ookinete development in vivo. We show that this arrest correlates with depolarization of the mitochondrial membrane potential (ΔΨmt). Our results underline the importance of SPFH proteins in the regulation of core mitochondrial functions and suggest that fine-tuning of ΔΨmt in malarial parasites is critical for colonization of the definitive host.
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Affiliation(s)
- Joachim Michael Matz
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Philippstraße 13, 10115 Berlin, Germany; Parasitology Unit, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany; Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, the Netherlands.
| | - Christian Goosmann
- Microscopy Core Facility, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Philippstraße 13, 10115 Berlin, Germany; Parasitology Unit, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany
| | - Taco Wilhelmus Antonius Kooij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, the Netherlands; Center for Molecular and Biomolecular Informatics and Radboud Center for Mitochondrial Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, the Netherlands.
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23
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Ngotho P, Soares AB, Hentzschel F, Achcar F, Bertuccini L, Marti M. Revisiting gametocyte biology in malaria parasites. FEMS Microbiol Rev 2019; 43:401-414. [PMID: 31220244 PMCID: PMC6606849 DOI: 10.1093/femsre/fuz010] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/05/2019] [Indexed: 12/21/2022] Open
Abstract
Gametocytes are the only form of the malaria parasite that is transmissible to the mosquito vector. They are present at low levels in blood circulation and significant knowledge gaps exist in their biology. Recent reductions in the global malaria burden have brought the possibility of elimination and eradication, with renewed focus on malaria transmission biology as a basis for interventions. This review discusses recent insights into gametocyte biology in the major human malaria parasite, Plasmodium falciparum and related species.
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Affiliation(s)
- Priscilla Ngotho
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Road, Glasgow G12 8TA, UK
| | - Alexandra Blancke Soares
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Road, Glasgow G12 8TA, UK
| | - Franziska Hentzschel
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Road, Glasgow G12 8TA, UK
| | - Fiona Achcar
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Road, Glasgow G12 8TA, UK
| | - Lucia Bertuccini
- Core Facilities, Microscopy Area, Instituto Superiore di Sanita, Via Regina Elena 299, 00161 Rome, Italy
| | - Matthias Marti
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Road, Glasgow G12 8TA, UK.,Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston 02115, MA, USA
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Hillebrand A, Matz JM, Almendinger M, Müller K, Matuschewski K, Schmitz-Linneweber C. Identification of clustered organellar short (cos) RNAs and of a conserved family of organellar RNA-binding proteins, the heptatricopeptide repeat proteins, in the malaria parasite. Nucleic Acids Res 2019; 46:10417-10431. [PMID: 30102371 PMCID: PMC6212722 DOI: 10.1093/nar/gky710] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 07/24/2018] [Indexed: 11/13/2022] Open
Abstract
Gene expression in mitochondria of Plasmodium falciparum is essential for parasite survival. The molecular mechanisms of Plasmodium organellar gene expression remain poorly understood. This includes the enigmatic assembly of the mitochondrial ribosome from highly fragmented rRNAs. Here, we present the identification of clustered organellar short RNA fragments (cosRNAs) that are possible footprints of RNA-binding proteins (RBPs) in Plasmodium organelles. In plants, RBPs of the pentatricopeptide repeat (PPR) class produce footprints as a consequence of their function in processing organellar RNAs. Intriguingly, many of the Plasmodium cosRNAs overlap with 5'-ends of rRNA fragments. We hypothesize that these are footprints of RBPs involved in assembling the rRNA fragments into a functioning ribosome. A bioinformatics search of the Plasmodium nuclear genome identified a hitherto unrecognized organellar helical-hairpin-repeat protein family that we term heptatricopeptide repeat (HPR) proteins. We demonstrate that selected HPR proteins are targeted to mitochondria in P. berghei and that one of them, PbHPR1, associates with RNA, but not DNA in vitro. A phylogenetic search identified HPR proteins in a wide variety of eukaryotes. We hypothesize that HPR proteins are required for processing and stabilizing RNAs in Apicomplexa and other taxa.
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Affiliation(s)
- Arne Hillebrand
- Humboldt University Berlin, Molecular Genetics, Berlin, Germany
| | - Joachim M Matz
- Humboldt University, Department of Molecular Parasitology, Berlin, Germany
| | | | - Katja Müller
- Humboldt University, Department of Molecular Parasitology, Berlin, Germany
| | - Kai Matuschewski
- Humboldt University, Department of Molecular Parasitology, Berlin, Germany
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Matthews KM, Kalanon M, de Koning-Ward TF. Uncoupling the Threading and Unfoldase Actions of Plasmodium HSP101 Reveals Differences in Export between Soluble and Insoluble Proteins. mBio 2019; 10:e01106-19. [PMID: 31164473 PMCID: PMC6550532 DOI: 10.1128/mbio.01106-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 12/02/2022] Open
Abstract
Plasmodium parasites must export proteins into their erythrocytic host to survive. Exported proteins must cross the parasite plasma membrane (PPM) and the parasitophorous vacuolar membrane (PVM) encasing the parasite to access the host cell. Crossing the PVM requires protein unfolding and passage through a translocon, the Plasmodium translocon of exported proteins (PTEX). In this study, we provide the first direct evidence that heat shock protein 101 (HSP101), a core component of PTEX, unfolds proteins for translocation across the PVM by creating transgenic Plasmodium parasites in which the unfoldase and translocation functions of HSP101 have become uncoupled. Strikingly, while these parasites could export native proteins, they were unable to translocate soluble, tightly folded reporter proteins bearing the Plasmodium export element (PEXEL) across the PVM into host erythrocytes under the same conditions. In contrast, an identical PEXEL reporter protein but harboring a transmembrane domain could be exported, suggesting that a prior unfolding step occurs at the PPM. Together, these results demonstrate that the export of parasite proteins is dependent on how these proteins are presented to the secretory pathway before they reach PTEX as well as their folded status. Accordingly, only tightly folded soluble proteins secreted into the vacuolar space and not proteins containing transmembrane domains or the majority of erythrocyte-stage exported proteins have an absolute requirement for the full unfoldase activity of HSP101 to be exported.IMPORTANCE The Plasmodium parasites that cause malaria export hundreds of proteins into their host red blood cell (RBC). These exported proteins drastically alter the structural and functional properties of the RBC and play critical roles in parasite virulence and survival. To access the RBC cytoplasm, parasite proteins must pass through the Plasmodium translocon of exported proteins (PTEX) located at the membrane interfacing the parasite and host cell. Our data provide evidence that HSP101, a component of PTEX, serves to unfold protein cargo requiring translocation. We also reveal that addition of a transmembrane domain to soluble cargo influences its ability to be translocated by parasites in which the HSP101 motor and unfolding activities have become uncoupled. Therefore, we propose that proteins with transmembrane domains use an alternative unfolding pathway prior to PTEX to facilitate export.
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Affiliation(s)
| | - Ming Kalanon
- School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
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Matthews KM, Pitman EL, de Koning-Ward TF. Illuminating how malaria parasites export proteins into host erythrocytes. Cell Microbiol 2019; 21:e13009. [PMID: 30656810 DOI: 10.1111/cmi.13009] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/06/2018] [Accepted: 12/17/2018] [Indexed: 12/11/2022]
Abstract
Plasmodium parasites that cause the disease malaria have developed an elaborate trafficking pathway to facilitate the export of hundreds of effector proteins into their host cell, the erythrocyte. In this review, we outline how certain effector proteins contribute to parasite survival, virulence, and immune evasion. We also highlight how parasite proteins destined for export are recognised at the endoplasmic reticulum to facilitate entry into the export pathway and how the effector proteins are able to transverse the bounding parasitophorous vaculoar membrane via the Plasmodium translocon of exported proteins to gain access to the host cell. Some of the gaps in our understanding of the export pathway are also presented. Finally, we examine the degree of conservation of some of the key components of the Plasmodium export pathway in closely related apicomplexan parasites, which may provide insight into how the diverse apicomplexan parasites have adapted to survival pressures encountered within their respective host cells.
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Affiliation(s)
| | - Ethan L Pitman
- School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
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A probabilistic model of pre-erythrocytic malaria vaccine combination in mice. PLoS One 2019; 14:e0209028. [PMID: 30625136 PMCID: PMC6326473 DOI: 10.1371/journal.pone.0209028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 11/27/2018] [Indexed: 11/19/2022] Open
Abstract
Malaria remains one the world’s most deadly infectious diseases, with almost half a million deaths and over 150 million clinical cases each year. An effective vaccine would contribute enormously to malaria control and will almost certainly be required for eventual eradication of the disease. However, the leading malaria vaccine candidate, RTS,S, shows only 30–50% efficacy under field conditions, making it less cost-effective than long-lasting insecticide treated bed nets. Other subunit malaria vaccine candidates, including TRAP-based vaccines, show no better protective efficacy. This has led to increased interest in combining subunit malaria vaccines as a means of enhancing protective efficacy. Mathematical models of the effect of combining such vaccines on protective efficacy can help inform optimal vaccine strategies and decision-making at all stages of the clinical process. So far, however, no such model has been developed for pre-clinical murine studies, the stage at which all candidate antigens and combinations begin evaluation. To address this gap, this paper develops a mathematical model of vaccine combination adapted to murine malaria studies. The model is based on simple probabilistic assumptions which put the model on a firmer theoretical footing than previous clinical models, which rather than deriving a relationship between immune responses and protective efficacy posit the relationship to be either exponential or Hill curves. Data from pre-clinical murine malaria studies are used to derive values for unknowns in the model which in turn allows simulations of vaccine combination efficacy and suggests optimal strategies to pursue. Finally, the ability of the model to shed light on fundamental biological variables of murine malaria such as the blood stage growth rate and sporozoite infectivity is explored.
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28
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Sanders PR, Dickerman BK, Charnaud SC, Ramsland PA, Crabb BS, Gilson PR. The N-terminus of EXP2 forms the membrane-associated pore of the protein exporting translocon PTEX in Plasmodium falciparum. J Biochem 2018; 165:239-248. [DOI: 10.1093/jb/mvy099] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/20/2018] [Indexed: 12/12/2022] Open
Affiliation(s)
| | | | | | - Paul A Ramsland
- Burnet Institute, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
- RMIT University, Bundoora, VIC, Australia
- Monash University, Melbourne, VIC, Australia
| | - Brendan S Crabb
- Burnet Institute, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
- Monash University, Melbourne, VIC, Australia
| | - Paul R Gilson
- Burnet Institute, Melbourne, VIC, Australia
- Monash University, Melbourne, VIC, Australia
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30
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Knockdown of the translocon protein EXP2 in Plasmodium falciparum reduces growth and protein export. PLoS One 2018; 13:e0204785. [PMID: 30439948 PMCID: PMC6237293 DOI: 10.1371/journal.pone.0204785] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/30/2018] [Indexed: 11/23/2022] Open
Abstract
Malaria parasites remodel their host erythrocytes to gain nutrients and avoid the immune system. Host erythrocytes are modified by hundreds of effector proteins exported from the parasite into the host cell. Protein export is mediated by the PTEX translocon comprising five core components of which EXP2 is considered to form the putative pore that spans the vacuole membrane enveloping the parasite within its erythrocyte. To explore the function and importance of EXP2 for parasite survival in the asexual blood stage of Plasmodium falciparum we inducibly knocked down the expression of EXP2. Reduction in EXP2 expression strongly reduced parasite growth proportional to the degree of protein knockdown and tended to stall development about half way through the asexual cell cycle. Once the knockdown inducer was removed and EXP2 expression restored, parasite growth recovered dependent upon the length and degree of knockdown. To establish EXP2 function and hence the basis for growth reduction, the trafficking of an exported protein was monitored following EXP2 knockdown. This resulted in severe attenuation of protein export and is consistent with EXP2, and PTEX in general, being the conduit for export of proteins into the host compartment.
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31
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Matz JM, Matuschewski K. An in silico down-scaling approach uncovers novel constituents of the Plasmodium-containing vacuole. Sci Rep 2018; 8:14055. [PMID: 30232409 PMCID: PMC6145888 DOI: 10.1038/s41598-018-32471-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 09/05/2018] [Indexed: 01/09/2023] Open
Abstract
During blood stage development the malaria parasite resides in a membrane-bound compartment, termed the parasitophorous vacuole (PV). The reasons for this intravacuolar life style and the molecular functions of this parasite-specific compartment remain poorly defined, which is mainly due to our limited knowledge about the molecular make-up of this unique niche. We used an in silico down-scaling approach to select for Plasmodium-specific candidates that harbour signatures of PV residency. Live co-localisation of five endogenously tagged proteins confirmed expression in the PV of Plasmodium berghei blood and liver stages. ER retention was ruled out by addition of the respective carboxyterminal tetrapeptides to a secreted reporter protein. Although all five PV proteins are highly expressed, four proved to be dispensable for parasite development in the mammalian and mosquito host, as revealed by targeted gene deletion. In good agreement with their redundant roles, the knockout parasites displayed no detectable deficiencies in protein export, sequestration, or PV morphology. Together, our approach improved the catalogue of the Plasmodium PV proteome and provides experimental genetics evidence for functional redundancy of several PV proteins.
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Affiliation(s)
- Joachim Michael Matz
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115, Berlin, Germany. .,Parasitology Unit, Max Planck Institute for Infection Biology, 10117, Berlin, Germany.
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, 10117, Berlin, Germany
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Chisholm SA, Kalanon M, Nebl T, Sanders PR, Matthews KM, Dickerman BK, Gilson PR, de Koning-Ward TF. The malaria PTEX component PTEX88 interacts most closely with HSP101 at the host-parasite interface. FEBS J 2018; 285:2037-2055. [PMID: 29637707 DOI: 10.1111/febs.14463] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 03/08/2018] [Accepted: 04/03/2018] [Indexed: 12/28/2022]
Abstract
The pathogenic nature of malaria infections is due in part to the export of hundreds of effector proteins that actively remodel the host erythrocyte. The Plasmodium translocon of exported proteins (PTEX) has been shown to facilitate the trafficking of proteins into the host cell, a process that is essential for the survival of the parasite. The role of the auxiliary PTEX component PTEX88 remains unclear, as previous attempts to elucidate its function through reverse genetic approaches showed that in contrast to the core components PTEX150 and HSP101, knockdown of PTEX88 did not give rise to an export phenotype. Here, we have used biochemical approaches to understand how PTEX88 assembles within the translocation machinery. Proteomic analysis of the PTEX88 interactome showed that PTEX88 interacts closely with HSP101 but has a weaker affinity with the other core constituents of PTEX. PTEX88 was also found to associate with other PV-resident proteins, including chaperones and members of the exported protein-interacting complex that interacts with the major virulence factor PfEMP1, the latter contributing to cytoadherence and parasite virulence. Despite being expressed for the duration of the blood-stage life cycle, PTEX88 was only discretely observed at the parasitophorous vacuole membrane during ring stages and could not always be detected in the major high molecular weight complex that contains the other core components of PTEX, suggesting that its interaction with the PTEX complex may be dynamic. Together, these data have enabled the generation of an updated model of PTEX that now includes how PTEX88 assembles within the complex.
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Affiliation(s)
| | - Ming Kalanon
- School of Medicine, Deakin University, Waurn Ponds, Australia
| | - Thomas Nebl
- The Walter and Eliza Hall Institute, Parkville, Australia
| | - Paul R Sanders
- Burnet Institute, Prahran, Australia.,Monash University, Melbourne, Australia
| | | | | | - Paul R Gilson
- Burnet Institute, Prahran, Australia.,Monash University, Melbourne, Australia
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Yang C, Liu J, Ma L, Zhang X, Zhang X, Zhou B, Zhu X, Liu Q. NcGRA17 is an important regulator of parasitophorous vacuole morphology and pathogenicity of Neospora caninum. Vet Parasitol 2018; 264:26-34. [PMID: 30503087 DOI: 10.1016/j.vetpar.2018.03.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 03/12/2018] [Accepted: 03/18/2018] [Indexed: 10/17/2022]
Abstract
Neospora caninum is an obligate intracellular protozoan parasite that infects a wide range of mammalian species, and particularly causes the reproductive loss in cattle. We identified a novel dense granule protein, N. caninum granule protein 17 (NcGRA17) using the CRISPR/cas9 genome editing system and studied its function. We generated the NcGRA17 knockout strain (ΔNcGRA17) and NcGRA17 complementary strain (iΔNcGRA17). Plaque assays and intracellular proliferation tests showed that the ΔNcGRA17 strain formed smaller plaques and had slower intracellular growth. Mouse virulence assay showed loss of virulence for the ΔNcGRA17 strain. We observed that the parasitophorous vacuoles (PVs) of NcGRA17-deficient parasites have aberrant morphology. To investigate the contribution of NcGRA17 α-helices to aberrant morphology of PVs, we transfected four truncated forms of NcGRA17 into NcGRA17 knockout strain and the phenotypes of these mutants were analysed. Lack of the N-terminal region (NT) failed to target the protein to dense granules, while NcGRA17 (Δα1)-HA, NcGRA17 (Δα2-4)-HA and NcGRA17 (Δα5-8)-HA were targeted to dense granules, but failed to rescue the aberrant PV morphology. Our results indicate that NcGRA17 as a dense granule protein determines PV morphology and pathogenicity, and α-helices of NcGRA17 may be responsible for the aberrant morphology of N. caninum PVs.
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Affiliation(s)
- Congshan Yang
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, China; Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, China
| | - Jing Liu
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, China; Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, China
| | - Lei Ma
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, China; Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, China
| | - Xichen Zhang
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Xiao Zhang
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, China; Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, China
| | - Bingxin Zhou
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, China; Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, China
| | - Xingquan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qun Liu
- National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, China; Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, China.
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Morita M, Nagaoka H, Ntege EH, Kanoi BN, Ito D, Nakata T, Lee JW, Tokunaga K, Iimura T, Torii M, Tsuboi T, Takashima E. PV1, a novel Plasmodium falciparum merozoite dense granule protein, interacts with exported protein in infected erythrocytes. Sci Rep 2018; 8:3696. [PMID: 29487358 PMCID: PMC5829233 DOI: 10.1038/s41598-018-22026-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 02/07/2018] [Indexed: 01/09/2023] Open
Abstract
Upon invasion, Plasmodium falciparum exports hundreds of proteins across its surrounding parasitophorous vacuole membrane (PVM) to remodel the infected erythrocyte. Although this phenomenon is crucial for the parasite growth and virulence, elucidation of precise steps in the export pathway is still required. A translocon protein complex, PTEX, is the only known pathway that mediates passage of exported proteins across the PVM. P. falciparum Parasitophorous Vacuolar protein 1 (PfPV1), a previously reported parasitophorous vacuole (PV) protein, is considered essential for parasite growth. In this study, we characterized PfPV1 as a novel merozoite dense granule protein. Structured illumination microscopy (SIM) analyses demonstrated that PfPV1 partially co-localized with EXP2, suggesting the protein could be a PTEX accessory molecule. Furthermore, PfPV1 and exported protein PTP5 co-immunoprecipitated with anti-PfPV1 antibody. Surface plasmon resonance (SPR) confirmed the proteins’ direct interaction. Additionally, we identified a PfPV1 High-affinity Region (PHR) at the C-terminal side of PTP5 where PfPV1 dominantly bound. SIM analysis demonstrated an export arrest of PTP5ΔPHR, a PTP5 mutant lacking PHR, suggesting PHR is essential for PTP5 export to the infected erythrocyte cytosol. The overall results suggest that PfPV1, a novel dense granule protein, plays an important role in protein export at PV.
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Affiliation(s)
- Masayuki Morita
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Edward H Ntege
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Bernard N Kanoi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Daisuke Ito
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan.,Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Tottori, 683-8503, Japan
| | - Takahiro Nakata
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Ji-Won Lee
- Division of Bio-Imaging, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime, Japan
| | | | - Tadahiro Iimura
- Division of Bio-Imaging, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime, Japan.,Division of Analytical Bio-Medicine, Advanced Research Support Center, Ehime University, Shitsukawa, Toon, Ehime, Japan
| | - Motomi Torii
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, Japan.
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Huang J, Xiong K, Zhang H, Zhao Y, Cao J, Gong H, Zhou Y, Zhou J. Molecular characterization of Babesia microti thioredoxin (BmTrx2) and its expression patterns induced by antiprotozoal drugs. Parasit Vectors 2018; 11:38. [PMID: 29335000 PMCID: PMC5769273 DOI: 10.1186/s13071-018-2619-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/02/2018] [Indexed: 11/10/2022] Open
Abstract
Background Human babesiosis is an infectious disease that is epidemic in various regions all over the world. The predominant causative pathogen of this disease is the intra-erythrocytic parasite Babesia microti. The thioredoxin system is one of the major weapons that is used in the resistance to the reactive oxygen species (ROS) and reactive nitrogen species (RNS) produced by host immune system. In other intra-erythrocytic apicomplexans like the malaria parasite Plasmodium falciparum, anti-oxidative proteins are promising targets for the development of anti-parasitic drugs. However, to date, the sequences and biological properties of thioredoxins and thioredoxin-like molecules of B. microti remain unknown. Understanding the molecular characterization and function of B. microti thioredoxins may help to develop anti-Babesia drugs and controlling babesiosis. Methods The full-length B. microti thioredoxin 2 (BmTrx2) gene was obtained using a rapid amplification of cDNA ends (RACE) method, and the deduced BmTrx2 amino acid sequence was analyzed using regular bioinformatics tools. Recombinant BmTrx2 protein was expressed in vitro and purified using His-tag protein affinity chromatography resins. Reverse transcription PCR, quantitative real-time PCR and Western blot were employed to detect the expression and native proteins of BmTrx2. Indirect immunofluorescence assay was used to localize BmTrx2 in B. microti. Bovine insulin reduction assays were used to determine the enzyme activity of the purified recombinant BmTrx2 protein. Results The full-length BmTrx2 was 564 bp with a 408 bp open reading frame encoding a protein of 135 amino acids. The predicted molecular weight of the protein was 15.5 kDa. A conserved thioredoxin-like family domain was found in BmTrx2. The expression of BmTrx2 was upregulated on both the third and eighth day post-infection in mice, whereas expression was downregulated during the beginning and later stages. The results of Western blot analysis showed the native BmTrx2 in parasite lysates could be detected by mouse anti-BmTrx2 serum and that the recombinant BmTrx2 protein could be recognized by serum of B. microti-infected mice. Immunofluorescence microscopy showed that BmTrx2 localized in the cell cytoplasm of B. microti merozoites in B. microti-infected red blood cells. The results of bovine insulin reduction assay indicated the purified recombinant BmTrx2 protein possesses antioxidant enzyme activity. Dihydroartemisinin and quinine, known anti-malaria drugs, and clindamycin, a known anti-babesiosis drug, induced significantly higher upregulation of BmTrx2 mRNA. Conclusions Our results indicate that BmTrx2 is a functional enzyme with antioxidant activity and may be involved in the response of B. microti to anti-parasite drugs. Electronic supplementary material The online version of this article (10.1186/s13071-018-2619-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jingwei Huang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Kang Xiong
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Houshuang Zhang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Yanzhen Zhao
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Jie Cao
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Haiyan Gong
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Yongzhi Zhou
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China
| | - Jinlin Zhou
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
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Nyboer B, Heiss K, Mueller AK, Ingmundson A. The Plasmodium liver-stage parasitophorous vacuole: A front-line of communication between parasite and host. Int J Med Microbiol 2017; 308:107-117. [PMID: 28964681 DOI: 10.1016/j.ijmm.2017.09.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/19/2017] [Accepted: 09/11/2017] [Indexed: 12/13/2022] Open
Abstract
The intracellular development and differentiation of the Plasmodium parasite in the host liver is a prerequisite for the actual onset of malaria disease pathology. Since liver-stage infection is clinically silent and can be completely eliminated by sterilizing immune responses, it is a promising target for urgently needed innovative antimalarial drugs and/or vaccines. Discovered more than 65 years ago, these stages remain poorly understood regarding their molecular repertoire and interaction with their host cells in comparison to the pathogenic erythrocytic stages. The differentiating and replicative intrahepatic parasite resides in a membranous compartment called the parasitophorous vacuole, separating it from the host-cell cytoplasm. Here we outline seminal work that contributed to our present understanding of the fundamental dynamic cellular processes of the intrahepatic malarial parasite with both specific host-cell factors and compartments.
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Affiliation(s)
- Britta Nyboer
- Centre for Infectious Diseases, Parasitology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Kirsten Heiss
- Centre for Infectious Diseases, Parasitology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; Centre for Infection Research (DZIF), D 69120 Heidelberg, Germany
| | - Ann-Kristin Mueller
- Centre for Infectious Diseases, Parasitology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; Centre for Infection Research (DZIF), D 69120 Heidelberg, Germany,.
| | - Alyssa Ingmundson
- Department of Molecular Parasitology, Institute of Biology, Humboldt University Berlin, Philippstrasse 13, 10115 Berlin, Germany.
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Hakamada K, Watanabe H, Kawano R, Noguchi K, Yohda M. Expression and characterization of the Plasmodium translocon of the exported proteins component EXP2. Biochem Biophys Res Commun 2017; 482:700-705. [DOI: 10.1016/j.bbrc.2016.11.097] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 11/16/2016] [Indexed: 10/20/2022]
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Distinct Prominent Roles for Enzymes of Plasmodium berghei Heme Biosynthesis in Sporozoite and Liver Stage Maturation. Infect Immun 2016; 84:3252-3262. [PMID: 27600503 DOI: 10.1128/iai.00148-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 08/29/2016] [Indexed: 11/20/2022] Open
Abstract
Malarial parasites have evolved complex regulation of heme supply and disposal to adjust to heme-rich and -deprived host environments. In addition to its own pathway for heme biosynthesis, Plasmodium likely harbors mechanisms for heme scavenging from host erythrocytes. Elaborate compartmentalization of de novo heme synthesis into three subcellular locations, including the vestigial plastid organelle, indicates critical roles in life cycle progression. In this study, we systematically profile the essentiality of heme biosynthesis by targeted gene deletion of enzymes in early steps of this pathway. We show that disruption of endogenous heme biosynthesis leads to a first detectable defect in oocyst maturation and sporogony in the Anopheles vector, whereas blood stage propagation, colonization of mosquito midguts, or initiation of oocyst development occurs indistinguishably from that of wild-type parasites. Although sporozoites are produced by parasites lacking an intact pathway for heme biosynthesis, they are absent from mosquito salivary glands, indicative of a vital role for heme biosynthesis only in sporozoite maturation. Rescue of the first defect in sporogony permitted analysis of potential roles in liver stages. We show that liver stage parasites benefit from but do not strictly depend upon their own aminolevulinic acid synthase and that they can scavenge aminolevulinic acid from the host environment. Together, our experimental genetics analysis of Plasmodium enzymes for heme biosynthesis exemplifies remarkable shifts between the use of endogenous and host resources during life cycle progression.
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Weiner J, Kooij TWA. Phylogenetic profiles of all membrane transport proteins of the malaria parasite highlight new drug targets. MICROBIAL CELL 2016; 3:511-521. [PMID: 28357319 PMCID: PMC5348985 DOI: 10.15698/mic2016.10.534] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In order to combat the on-going malaria epidemic, discovery of new drug targets
remains vital. Proteins that are essential to survival and specific to malaria
parasites are key candidates. To survive within host cells, the parasites need
to acquire nutrients and dispose of waste products across multiple membranes.
Additionally, like all eukaryotes, they must redistribute ions and organic
molecules between their various internal membrane bound compartments. Membrane
transport proteins mediate all of these processes and are considered important
mediators of drug resistance as well as drug targets in their own right.
Recently, using advanced experimental genetic approaches and streamlined life
cycle profiling, we generated a large collection of Plasmodium
berghei gene deletion mutants and assigned essential gene
functions, highlighting potential targets for prophylactic, therapeutic, and
transmission-blocking anti-malarial drugs. Here, we present a comprehensive
orthology assignment of all Plasmodium falciparum putative
membrane transport proteins and provide a detailed overview of the associated
essential gene functions obtained through experimental genetics studies in human
and murine model parasites. Furthermore, we discuss the phylogeny of selected
potential drug targets identified in our functional screen. We extensively
discuss the results in the context of the functional assignments obtained using
gene targeting available to date.
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Affiliation(s)
- January Weiner
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Taco W A Kooij
- Department of Medical Microbiology & Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
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40
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Siau A, Huang X, Weng M, Sze SK, Preiser PR. Proteome mapping of Plasmodium: identification of the P. yoelii remodellome. Sci Rep 2016; 6:31055. [PMID: 27503796 PMCID: PMC4977464 DOI: 10.1038/srep31055] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 07/13/2016] [Indexed: 11/17/2022] Open
Abstract
Plasmodium associated virulence in the host is linked to extensive remodelling of the host erythrocyte by parasite proteins that form the “remodellome”. However, without a common motif or structure available to identify these proteins, little is known about the proteins that are destined to reside in the parasite periphery, the host-cell cytoplasm and/or the erythrocyte membrane. Here, the subcellular fractionation of erythrocytic P. yoelii at trophozoite and schizont stage along with label-free quantitative LC-MS/MS analysis of the whole proteome, revealed a proteome of 1335 proteins. Differential analysis of the relative abundance of these proteins across the subcellular compartments allowed us to map their locations, independently of their predicted features. These results, along with literature data and in vivo validation of 61 proteins enabled the identification of a remodellome of 184 proteins. This approach identified a significant number of conserved remodelling proteins across plasmodium that likely represent key conserved functions in the parasite and provides new insights into parasite evolution and biology.
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Affiliation(s)
- Anthony Siau
- Nanyang Technological University, School of Biological Sciences, 637551, Singapore
| | - Ximei Huang
- Nanyang Technological University, School of Biological Sciences, 637551, Singapore
| | - Mei Weng
- Nanyang Technological University, School of Biological Sciences, 637551, Singapore
| | - Siu Kwan Sze
- Nanyang Technological University, School of Biological Sciences, 637551, Singapore
| | - Peter R Preiser
- Nanyang Technological University, School of Biological Sciences, 637551, Singapore
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41
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de Koning-Ward TF, Dixon MW, Tilley L, Gilson PR. Plasmodium species: master renovators of their host cells. Nat Rev Microbiol 2016; 14:494-507. [DOI: 10.1038/nrmicro.2016.79] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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42
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Gilson PR, Chisholm SA, Crabb BS, de Koning-Ward TF. Host cell remodelling in malaria parasites: a new pool of potential drug targets. Int J Parasitol 2016; 47:119-127. [PMID: 27368610 DOI: 10.1016/j.ijpara.2016.06.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/02/2016] [Accepted: 06/04/2016] [Indexed: 12/01/2022]
Abstract
When in their human hosts, malaria parasites spend most of their time housed within vacuoles inside erythrocytes and hepatocytes. The parasites extensively modify their host cells to obtain nutrients, prevent host cell breakdown and avoid the immune system. To perform these modifications, malaria parasites export hundreds of effector proteins into their host cells and this process is best understood in the most lethal species to infect humans, Plasmodium falciparum. The effector proteins are synthesized within the parasite and following a proteolytic cleavage event in the endoplasmic reticulum and sorting of mature proteins into the correct vesicular trafficking pathway, they are transported to the parasite surface and released into the vacuole. The effector proteins are then unfolded before extrusion across the vacuole membrane by a unique translocon complex called Plasmodium translocon of exported proteins. After gaining access to the erythrocyte cytoplasm many effector proteins continue their journey to the erythrocyte surface by utilising various membranous structures established by the parasite. This complex trafficking pathway and a large number of the effector proteins are unique to Plasmodium parasites. This pathway could, therefore, be developed as new drug targets given that protein export and the functional role of these proteins are essential for parasite survival. This review explores known and potential drug targetable steps in the protein export pathway and strategies for discovering novel drug targets.
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Affiliation(s)
- Paul R Gilson
- Burnet Institute, Melbourne, Victoria, Australia; Monash University, Melbourne, Victoria, Australia.
| | | | - Brendan S Crabb
- Burnet Institute, Melbourne, Victoria, Australia; Monash University, Melbourne, Victoria, Australia; University of Melbourne, Melbourne, Victoria, Australia
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43
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Protein trafficking in apicomplexan parasites: crossing the vacuolar Rubicon. Curr Opin Microbiol 2016; 32:38-45. [PMID: 27155394 DOI: 10.1016/j.mib.2016.04.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/08/2016] [Accepted: 04/12/2016] [Indexed: 01/01/2023]
Abstract
Although apicomplexans like the blood stages of Plasmodium and the actively replicating 'tachyzoite' stage of Toxoplasma infect very dissimilar host cells, recent studies suggest they share molecular commonalities amongst differences at the parasitophorous vacuolar membrane (PVM) surrounding these intracellular parasites. A protein translocation export (PTEX) complex in the PVM of Plasmodium, is functionally informed by findings in Toxoplasma. Lipids play a role in trafficking to and across the PVM. Toxoplasma exploit an orthologue of a plasmodial secretory aspartyl protease but substrate cleavage yields a signal for targeting to the PVM, rather than directly to the host cell. The studies significantly advance understanding of how trafficking to and across the host-pathogen PVM boundary induces virulence and disease in different host milieu.
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44
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Elsworth B, Sanders PR, Nebl T, Batinovic S, Kalanon M, Nie CQ, Charnaud SC, Bullen HE, de Koning Ward TF, Tilley L, Crabb BS, Gilson PR. Proteomic analysis reveals novel proteins associated with the Plasmodium protein exporter PTEX and a loss of complex stability upon truncation of the core PTEX component, PTEX150. Cell Microbiol 2016; 18:1551-1569. [PMID: 27019089 DOI: 10.1111/cmi.12596] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 03/11/2016] [Accepted: 03/22/2016] [Indexed: 11/28/2022]
Abstract
The Plasmodium translocon for exported proteins (PTEX) has been established as the machinery responsible for the translocation of all classes of exported proteins beyond the parasitophorous vacuolar membrane of the intraerythrocytic malaria parasite. Protein export, particularly in the asexual blood stage, is crucial for parasite survival as exported proteins are involved in remodelling the host cell, an essential process for nutrient uptake, waste removal and immune evasion. Here, we have truncated the conserved C-terminus of one of the essential PTEX components, PTEX150, in Plasmodium falciparum in an attempt to create mutants of reduced functionality. Parasites tolerated C-terminal truncations of up to 125 amino acids with no reduction in growth, protein export or the establishment of new permeability pathways. Quantitative proteomic approaches however revealed a decrease in other PTEX subunits associating with PTEX150 in truncation mutants, suggesting a role for the C-terminus of PTEX150 in regulating PTEX stability. Our analyses also reveal three previously unreported PTEX-associated proteins, namely PV1, Pf113 and Hsp70-x (respective PlasmoDB numbers; PF3D7_1129100, PF3D7_1420700 and PF3D7_0831700) and demonstrate that core PTEX proteins exist in various distinct multimeric forms outside the major complex.
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Affiliation(s)
- Brendan Elsworth
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.,Monash University, Melbourne, VIC, 3800, Australia
| | - Paul R Sanders
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Thomas Nebl
- Walter & Eliza Hall Institute, Melbourne, VIC, 3052, Australia
| | - Steven Batinovic
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, VIC, Australia.,ARC Centre of Excellence for Coherent X-ray Science, The University of Melbourne, Melbourne, VIC, Australia.,Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, Australia
| | | | - Catherine Q Nie
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Sarah C Charnaud
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.,Monash University, Melbourne, VIC, 3800, Australia
| | - Hayley E Bullen
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia
| | | | - Leann Tilley
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, VIC, Australia.,ARC Centre of Excellence for Coherent X-ray Science, The University of Melbourne, Melbourne, VIC, Australia.,Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Brendan S Crabb
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia.,Monash University, Melbourne, VIC, 3800, Australia.,University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Paul R Gilson
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, 3004, Australia. .,Monash University, Melbourne, VIC, 3800, Australia.
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45
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Efficient monitoring of the blood-stage infection in a malaria rodent model by the rotating-crystal magneto-optical method. Sci Rep 2016; 6:23218. [PMID: 26983695 PMCID: PMC4794716 DOI: 10.1038/srep23218] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 02/26/2016] [Indexed: 11/29/2022] Open
Abstract
Intense research efforts have been focused on the improvement of the efficiency and sensitivity of malaria diagnostics, especially in resource-limited settings for the detection of asymptomatic infections. Our recently developed magneto-optical (MO) method allows the accurate quantification of malaria pigment crystals (hemozoin) in blood by their magnetically induced rotation. First evaluations of the method using β-hematin crystals and in vitro P. falciparum cultures implied its potential for high-sensitivity malaria diagnosis. To further investigate this potential, here we study the performance of the method in monitoring the in vivo onset and progression of the blood-stage infection in a rodent malaria model. Our results show that the MO method can detect the first generation of intraerythrocytic P. berghei parasites 66–76 hours after sporozoite injection, demonstrating similar sensitivity to Giesma-stained light microscopy and exceeding that of flow cytometric techniques. Magneto-optical measurements performed during and after the treatment of P. berghei infections revealed that both the follow up under treatment and the detection of later reinfections are feasible with this new technique. The present study demonstrates that the MO method – besides being label and reagent-free, automated and rapid – has a high in vivo sensitivity and is ready for in-field evaluation.
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46
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Chisholm SA, McHugh E, Lundie R, Dixon MWA, Ghosh S, O’Keefe M, Tilley L, Kalanon M, de Koning-Ward TF. Contrasting Inducible Knockdown of the Auxiliary PTEX Component PTEX88 in P. falciparum and P. berghei Unmasks a Role in Parasite Virulence. PLoS One 2016; 11:e0149296. [PMID: 26886275 PMCID: PMC4757573 DOI: 10.1371/journal.pone.0149296] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/29/2016] [Indexed: 12/21/2022] Open
Abstract
Pathogenesis of malaria infections is linked to remodeling of erythrocytes, a process dependent on the trafficking of hundreds of parasite-derived proteins into the host erythrocyte. Recent studies have demonstrated that the Plasmodium translocon of exported proteins (PTEX) serves as the central gateway for trafficking of these proteins, as inducible knockdown of the core PTEX constituents blocked the trafficking of all classes of cargo into the erythrocyte. However, the role of the auxiliary component PTEX88 in protein export remains less clear. Here we have used inducible knockdown technologies in P. falciparum and P. berghei to assess the role of PTEX88 in parasite development and protein export, which reveal that the in vivo growth of PTEX88-deficient parasites is hindered. Interestingly, we were unable to link this observation to a general defect in export of a variety of known parasite proteins, suggesting that PTEX88 functions in a different fashion to the core PTEX components. Strikingly, PTEX88-deficient P. berghei were incapable of causing cerebral malaria despite a robust pro-inflammatory response from the host. These parasites also exhibited a reduced ability to sequester in peripheral tissues and were removed more readily from the circulation by the spleen. In keeping with these findings, PTEX88-deficient P. falciparum-infected erythrocytes displayed reduced binding to the endothelial cell receptor, CD36. This suggests that PTEX88 likely plays a specific direct or indirect role in mediating parasite sequestration rather than making a universal contribution to the trafficking of all exported proteins.
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Affiliation(s)
- Scott A. Chisholm
- School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
| | - Emma McHugh
- Department of Biochemistry and Molecular Biology, Bio21 Institute, Melbourne, Victoria, Australia
| | - Rachel Lundie
- The Burnet Institute, Melbourne, Victoria, Australia
| | - Matthew W. A. Dixon
- Department of Biochemistry and Molecular Biology, Bio21 Institute, Melbourne, Victoria, Australia
| | - Sreejoyee Ghosh
- School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
| | | | - Leann Tilley
- Department of Biochemistry and Molecular Biology, Bio21 Institute, Melbourne, Victoria, Australia
| | - Ming Kalanon
- School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
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47
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Functional profiles of orphan membrane transporters in the life cycle of the malaria parasite. Nat Commun 2016; 7:10519. [PMID: 26796412 PMCID: PMC4736113 DOI: 10.1038/ncomms10519] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 12/15/2015] [Indexed: 01/28/2023] Open
Abstract
Assigning function to orphan membrane transport proteins and prioritizing candidates for detailed biochemical characterization remain fundamental challenges and are particularly important for medically relevant pathogens, such as malaria parasites. Here we present a comprehensive genetic analysis of 35 orphan transport proteins of Plasmodium berghei during its life cycle in mice and Anopheles mosquitoes. Six genes, including four candidate aminophospholipid transporters, are refractory to gene deletion, indicative of essential functions. We generate and phenotypically characterize 29 mutant strains with deletions of individual transporter genes. Whereas seven genes appear to be dispensable under the experimental conditions tested, deletion of any of the 22 other genes leads to specific defects in life cycle progression in vivo and/or host transition. Our study provides growing support for a potential link between heavy metal homeostasis and host switching and reveals potential targets for rational design of new intervention strategies against malaria. The functions of many putative membrane transport proteins of malaria parasites are unknown. Here, Kenthirapalan et al. use mutant strains carrying targeted gene deletions to study the functions of 35 such proteins during the life cycle of Plasmodium berghei in mosquito and mouse hosts.
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48
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Malaria Parasite Proteins and Their Role in Alteration of the Structure and Function of Red Blood Cells. ADVANCES IN PARASITOLOGY 2015; 91:1-86. [PMID: 27015947 DOI: 10.1016/bs.apar.2015.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Malaria, caused by Plasmodium spp., continues to be a major threat to human health and a significant cause of socioeconomic hardship in many countries. Almost half of the world's population live in malaria-endemic regions and many of them suffer one or more, often life-threatening episodes of malaria every year, the symptoms of which are attributable to replication of the parasite within red blood cells (RBCs). In the case of Plasmodium falciparum, the species responsible for most malaria-related deaths, parasite replication within RBCs is accompanied by striking alterations to the morphological, biochemical and biophysical properties of the host cell that are essential for the parasites' survival. To achieve this, the parasite establishes a unique and extensive protein export network in the infected RBC, dedicating at least 6% of its genome to the process. Understanding the full gamut of proteins involved in this process and the mechanisms by which P. falciparum alters the structure and function of RBCs is important both for a more complete understanding of the pathogenesis of malaria and for development of new therapeutic strategies to prevent or treat this devastating disease. This review focuses on what is currently known about exported parasite proteins, their interactions with the RBC and their likely pathophysiological consequences.
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49
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Kalanon M, Bargieri D, Sturm A, Matthews K, Ghosh S, Goodman CD, Thiberge S, Mollard V, McFadden GI, Ménard R, Koning‐Ward TF. The
Plasmodium
translocon of exported proteins component EXP2 is critical for establishing a patent malaria infection in mice. Cell Microbiol 2015; 18:399-412. [DOI: 10.1111/cmi.12520] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 08/26/2015] [Accepted: 08/31/2015] [Indexed: 12/12/2022]
Affiliation(s)
- Ming Kalanon
- Molecular and Medical Research Unit, School of MedicineDeakin University Waurn Ponds Geelong Victoria 3216 Australia
| | - Daniel Bargieri
- Unité de Biologie et Génétique du PaludismeInstitut Pasteur Paris France
- Department of Parasitology, Institute of Biomedical SciencesUniversity of São Paulo São Paulo SP Brazil
| | - Angelika Sturm
- School of BioSciencesThe University of Melbourne Parkville Victoria 3010 Australia
| | - Kathryn Matthews
- Molecular and Medical Research Unit, School of MedicineDeakin University Waurn Ponds Geelong Victoria 3216 Australia
| | - Sreejoyee Ghosh
- Molecular and Medical Research Unit, School of MedicineDeakin University Waurn Ponds Geelong Victoria 3216 Australia
| | | | - Sabine Thiberge
- Unité de Biologie et Génétique du PaludismeInstitut Pasteur Paris France
| | - Vanessa Mollard
- School of BioSciencesThe University of Melbourne Parkville Victoria 3010 Australia
| | - Geoffrey I. McFadden
- School of BioSciencesThe University of Melbourne Parkville Victoria 3010 Australia
| | - Robert Ménard
- Unité de Biologie et Génétique du PaludismeInstitut Pasteur Paris France
| | - Tania F. Koning‐Ward
- Molecular and Medical Research Unit, School of MedicineDeakin University Waurn Ponds Geelong Victoria 3216 Australia
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50
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Spielmann T, Gilberger TW. Critical Steps in Protein Export of Plasmodium falciparum Blood Stages. Trends Parasitol 2015; 31:514-525. [DOI: 10.1016/j.pt.2015.06.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/16/2015] [Accepted: 06/24/2015] [Indexed: 11/29/2022]
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