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Martinez M, Bouillon A, Brûlé S, Raynal B, Haouz A, Alzari PM, Barale JC. Prodomain-driven enzyme dimerization: a pH-dependent autoinhibition mechanism that controls Plasmodium Sub1 activity before merozoite egress. mBio 2024; 15:e0019824. [PMID: 38386597 PMCID: PMC10936178 DOI: 10.1128/mbio.00198-24] [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: 01/25/2024] [Accepted: 01/31/2024] [Indexed: 02/24/2024] Open
Abstract
Malaria symptoms are associated with the asexual multiplication of Plasmodium falciparum within human red blood cells (RBCs) and fever peaks coincide with the egress of daughter merozoites following the rupture of the parasitophorous vacuole (PV) and the RBC membranes. Over the last two decades, it has emerged that the release of competent merozoites is tightly regulated by a complex cascade of events, including the unusual multi-step activation mechanism of the pivotal subtilisin-like protease 1 (Sub1) that takes place in three different cellular compartments and remains poorly understood. Following an initial auto-maturation in the endoplasmic reticulum (ER) between its pro- and catalytic domains, the Sub1 prodomain (PD) undergoes further cleavages by the parasite aspartic protease plasmepsin X (PmX) within acidic secretory organelles that ultimately lead to full Sub1 activation upon discharge into the PV. Here, we report the crystal structure of full-length P. falciparum Sub1 (PfS1FL) and demonstrate, through structural, biochemical, and biophysical studies, that the atypical Plasmodium-specific Sub1 PD directly promotes the assembly of inactive enzyme homodimers at acidic pH, whereas Sub1 is primarily monomeric at neutral pH. Our results shed new light into the finely tuned Sub1 spatiotemporal activation during secretion, explaining how PmX processing and full activation of Sub1 can occur in different cellular compartments, and uncover a robust mechanism of pH-dependent subtilisin autoinhibition that plays a key role in P. falciparum merozoites egress from infected host cells.IMPORTANCEMalaria fever spikes are due to the rupture of infected erythrocytes, allowing the egress of Plasmodium sp. merozoites and further parasite propagation. This fleeting tightly regulated event involves a cascade of enzymes, culminating with the complex activation of the subtilisin-like protease 1, Sub1. Differently than other subtilisins, Sub1 activation strictly depends upon the processing by a parasite aspartic protease within acidic merozoite secretory organelles. However, Sub1 biological activity is required in the pH neutral parasitophorous vacuole, to prime effectors involved in the rupture of the vacuole and erythrocytic membranes. Here, we show that the unusual, parasite-specific Sub1 prodomain is directly responsible for its acidic-dependent dimerization and autoinhibition, required for protein secretion, before its full activation at neutral pH in a monomeric form. pH-dependent Sub1 dimerization defines a novel, essential regulatory element involved in the finely tuned spatiotemporal activation of the egress of competent Plasmodium merozoites.
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Affiliation(s)
- Mariano Martinez
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Anthony Bouillon
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Sébastien Brûlé
- Plate-forme de Biophysique Moleculaire-C2RT, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Bertrand Raynal
- Plate-forme de Biophysique Moleculaire-C2RT, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Ahmed Haouz
- Plate-forme de Cristallographie-C2RT, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Pedro M. Alzari
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Jean-Christophe Barale
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
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2
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Sassmannshausen J, Bennink S, Distler U, Küchenhoff J, Minns AM, Lindner SE, Burda PC, Tenzer S, Gilberger TW, Pradel G. Comparative proteomics of vesicles essential for the egress of Plasmodium falciparum gametocytes from red blood cells. Mol Microbiol 2024; 121:431-452. [PMID: 37492994 DOI: 10.1111/mmi.15125] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 07/27/2023]
Abstract
Transmission of malaria parasites to the mosquito is mediated by sexual precursor cells, the gametocytes. Upon entering the mosquito midgut, the gametocytes egress from the enveloping erythrocyte while passing through gametogenesis. Egress follows an inside-out mode during which the membrane of the parasitophorous vacuole (PV) ruptures prior to the erythrocyte membrane. Membrane rupture requires exocytosis of specialized egress vesicles of the parasites; that is, osmiophilic bodies (OBs) involved in rupturing the PV membrane, and vesicles that harbor the perforin-like protein PPLP2 (here termed P-EVs) required for erythrocyte lysis. While some OB proteins have been identified, like G377 and MDV1/Peg3, the majority of egress vesicle-resident proteins is yet unknown. Here, we used high-resolution imaging and BioID methods to study the two egress vesicle types in Plasmodium falciparum gametocytes. We show that OB exocytosis precedes discharge of the P-EVs and that exocytosis of the P-EVs, but not of the OBs, is calcium sensitive. Both vesicle types exhibit distinct proteomes with the majority of proteins located in the OBs. In addition to known egress-related proteins, we identified novel components of OBs and P-EVs, including vesicle-trafficking proteins. Our data provide insight into the immense molecular machinery required for the inside-out egress of P. falciparum gametocytes.
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Affiliation(s)
- Juliane Sassmannshausen
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Sandra Bennink
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Ute Distler
- Core Facility for Mass Spectrometry, Institute of Immunology, University Medical Centre of the Johannes-Gutenberg University, Mainz, Germany
| | - Juliane Küchenhoff
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Allen M Minns
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Scott E Lindner
- Department of Biochemistry and Molecular Biology, Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Paul-Christian Burda
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Stefan Tenzer
- Core Facility for Mass Spectrometry, Institute of Immunology, University Medical Centre of the Johannes-Gutenberg University, Mainz, Germany
| | - Tim W Gilberger
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
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3
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Scheiner M, Burda PC, Ingmundson A. Moving on: How malaria parasites exit the liver. Mol Microbiol 2024; 121:328-340. [PMID: 37602900 DOI: 10.1111/mmi.15141] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023]
Abstract
An essential step in the life cycle of malaria parasites is their egress from hepatocytes, which enables the transition from the asymptomatic liver stage to the pathogenic blood stage of infection. To exit the liver, Plasmodium parasites first disrupt the parasitophorous vacuole membrane that surrounds them during their intracellular replication. Subsequently, parasite-filled structures called merosomes emerge from the infected cell. Shrouded by host plasma membrane, like in a Trojan horse, parasites enter the vasculature undetected by the host immune system and travel to the lung where merosomes rupture, parasites are released, and the blood infection stage begins. This complex, multi-step process must be carefully orchestrated by the parasite and requires extensive manipulation of the infected host cell. This review aims to outline the known signaling pathways that trigger exit, highlight Plasmodium proteins that contribute to the release of liver-stage merozoites, and summarize the accompanying changes to the hepatic host cell.
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Affiliation(s)
- Mattea Scheiner
- Molecular Parasitology, Humboldt University Berlin, Berlin, Germany
| | - Paul-Christian Burda
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- University of Hamburg, Hamburg, Germany
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4
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Siau A, Ang JW, Sheriff O, Hoo R, Loh HP, Tay D, Huang X, Yam XY, Lai SK, Meng W, Julca I, Kwan SS, Mutwil M, Preiser PR. Comparative spatial proteomics of Plasmodium-infected erythrocytes. Cell Rep 2023; 42:113419. [PMID: 37952150 DOI: 10.1016/j.celrep.2023.113419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 07/14/2023] [Accepted: 10/25/2023] [Indexed: 11/14/2023] Open
Abstract
Plasmodium parasites contribute to one of the highest global infectious disease burdens. To achieve this success, the parasite has evolved a range of specialized subcellular compartments to extensively remodel the host cell for its survival. The information to fully understand these compartments is likely hidden in the so far poorly characterized Plasmodium species spatial proteome. To address this question, we determined the steady-state subcellular location of more than 12,000 parasite proteins across five different species by extensive subcellular fractionation of erythrocytes infected by Plasmodium falciparum, Plasmodium knowlesi, Plasmodium yoelii, Plasmodium berghei, and Plasmodium chabaudi. This comparison of the pan-species spatial proteomes and their expression patterns indicates increasing species-specific proteins associated with the more external compartments, supporting host adaptations and post-transcriptional regulation. The spatial proteome offers comprehensive insight into the different human, simian, and rodent Plasmodium species, establishing a powerful resource for understanding species-specific host adaptation processes in the parasite.
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Affiliation(s)
- Anthony Siau
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Jing Wen Ang
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Omar Sheriff
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Regina Hoo
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Han Ping Loh
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Donald Tay
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Ximei Huang
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Xue Yan Yam
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Soak Kuan Lai
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Wei Meng
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Irene Julca
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Sze Siu Kwan
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Marek Mutwil
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore
| | - Peter R Preiser
- Nanyang Technological University, School of Biological Sciences, Singapore 637551, Singapore.
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5
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Triglia T, Scally SW, Seager BA, Pasternak M, Dagley LF, Cowman AF. Plasmepsin X activates the PCRCR complex of Plasmodium falciparum by processing PfRh5 for erythrocyte invasion. Nat Commun 2023; 14:2219. [PMID: 37072430 PMCID: PMC10113190 DOI: 10.1038/s41467-023-37890-2] [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: 01/03/2023] [Accepted: 04/04/2023] [Indexed: 04/20/2023] Open
Abstract
Plasmodium falciparum causes the most severe form of malaria in humans. The protozoan parasite develops within erythrocytes to mature schizonts, that contain more than 16 merozoites, which egress and invade fresh erythrocytes. The aspartic protease plasmepsin X (PMX), processes proteins and proteases essential for merozoite egress from the schizont and invasion of the host erythrocyte, including the leading vaccine candidate PfRh5. PfRh5 is anchored to the merozoite surface through a 5-membered complex (PCRCR), consisting of Plasmodium thrombospondin-related apical merozoite protein, cysteine-rich small secreted protein, Rh5-interacting protein and cysteine-rich protective antigen. Here, we show that PCRCR is processed by PMX in micronemes to remove the N-terminal prodomain of PhRh5 and this activates the function of the complex unmasking a form that can bind basigin on the erythrocyte membrane and mediate merozoite invasion. The ability to activate PCRCR at a specific time in merozoite invasion most likely masks potential deleterious effects of its function until they are required. These results provide an important understanding of the essential role of PMX and the fine regulation of PCRCR function in P. falciparum biology.
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Affiliation(s)
- Tony Triglia
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Stephen W Scally
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Benjamin A Seager
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Michał Pasternak
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Laura F Dagley
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia.
- University of Melbourne, Melbourne, VIC, 3010, Australia.
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6
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Abstract
Human malaria, caused by infection with Plasmodium parasites, remains one of the most important global public health problems, with the World Health Organization reporting more than 240 million cases and 600,000 deaths annually as of 2020 (World malaria report 2021). Our understanding of the biology of these parasites is critical for development of effective therapeutics and prophylactics, including both antimalarials and vaccines. Plasmodium is a protozoan organism that is intracellular for most of its life cycle. However, to complete its complex life cycle and to allow for both amplification and transmission, the parasite must egress out of the host cell in a highly regulated manner. This review discusses the major pathways and proteins involved in the egress events during the Plasmodium life cycle-merozoite and gametocyte egress out of red blood cells, sporozoite egress out of the oocyst, and merozoite egress out of the hepatocyte. The similarities, as well as the differences, between the various egress pathways of the parasite highlight both novel cell biology and potential therapeutic targets to arrest its life cycle.
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Affiliation(s)
- Jeffrey D Dvorin
- Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, USA;
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Daniel E Goldberg
- Division of Infectious Diseases, Department of Medicine; and Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA;
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7
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Abugri J, Ayariga J, Sunwiale SS, Wezena CA, Gyamfi JA, Adu-Frimpong M, Agongo G, Dongdem JT, Abugri D, Dinko B. Targeting the Plasmodium falciparum proteome and organelles for potential antimalarial drug candidates. Heliyon 2022; 8:e10390. [PMID: 36033316 PMCID: PMC9398786 DOI: 10.1016/j.heliyon.2022.e10390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 01/12/2022] [Accepted: 08/15/2022] [Indexed: 11/28/2022] Open
Abstract
There is an unmet need to unearth alternative treatment options for malaria, wherein this quest is more pressing in recent times due to high morbidity and mortality data arising mostly from the endemic countries coupled with partial diversion of attention from the disease in view of the SARS-Cov-2 pandemic. Available therapeutic options for malaria have been severely threatened with the emergence of resistance to almost all the antimalarial drugs by the Plasmodium falciparum parasite in humans, which is a worrying situation. Artemisinin combination therapies (ACT) that have so far been the mainstay of malaria have encountered resistance by malaria parasite in South East Asia, which is regarded as a notorious ground zero for the emergence of resistance to antimalarial drugs. This review analyzes a few key druggable targets for the parasite and the potential of specific inhibitors to mitigate the emerging antimalarial drug resistance problem by providing a concise assessment of the essential proteins of the malaria parasite that could serve as targets. Moreover, this work provides a summary of the advances made in malaria parasite biology and the potential to leverage these findings for antimalarial drug production.
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Affiliation(s)
- James Abugri
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Joseph Ayariga
- The Biomedical Engineering Programme, Alabama State University, Montgomery, AL, 36104, USA
| | - Samuel Sunyazi Sunwiale
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Cletus Adiyaga Wezena
- Department of Microbiology, School of Biosciences, University for Development Studies (UDS), Nyankpala Campus, Tamale, Ghana
| | - Julien Agyemang Gyamfi
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Michael Adu-Frimpong
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Godfred Agongo
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Julius Tieroyaare Dongdem
- Department of Biochemistry and Molecular Medicine. School of Medicine. University for Development Studies (UDS), Tamale-Campus, Ghana
| | - Daniel Abugri
- Department of Biological Sciences, Microbiology PhD Programme, Laboratory of Ethnomedicine, Parasitology, and Drug Discovery, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, USA
| | - Bismarck Dinko
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho. Ghana
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8
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Giorgalli M, Cunningham DA, Broncel M, Sait A, Harrison TE, Hosking C, Vandomme A, Amis SI, Antonello A, Sullivan L, Uwadiae F, Torella L, Higgins MK, Langhorne J. Differential Trafficking and Expression of PIR Proteins in Acute and Chronic Plasmodium Infections. Front Cell Infect Microbiol 2022; 12:877253. [PMID: 35782145 PMCID: PMC9245118 DOI: 10.3389/fcimb.2022.877253] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/12/2022] [Indexed: 12/02/2022] Open
Abstract
Plasmodium multigene families are thought to play important roles in the pathogenesis of malaria. Plasmodium interspersed repeat (pir) genes comprise the largest multigene family in many Plasmodium species. However, their expression pattern and localisation remain to be elucidated. Understanding protein subcellular localisation is fundamental to reveal the functional importance and cell-cell interactions of the PIR proteins. Here, we use the rodent malaria parasite, Plasmodium chabaudi chabaudi, as a model to investigate the localisation pattern of this gene family. We found that most PIR proteins are co-expressed in clusters during acute and chronic infection; members of the S7 clade are predominantly expressed during the acute-phase, whereas members of the L1 clade dominate the chronic-phase of infection. Using peptide antisera specific for S7 or L1 PIRS, we show that these PIRs have different localisations within the infected red blood cells. S7 PIRs are exported into the infected red blood cell cytoplasm where they are co-localised with parasite-induced host cell modifications termed Maurer’s clefts, whereas L1 PIRs are localised on or close to the parasitophorous vacuolar membrane. This localisation pattern changes following mosquito transmission and during progression from acute- to chronic-phase of infection. The presence of PIRs in Maurer’s clefts, as seen for Plasmodium falciparum RIFIN and STEVOR proteins, might suggest trafficking of the PIRs on the surface of the infected erythrocytes. However, neither S7 nor L1 PIR proteins detected by the peptide antisera are localised on the surface of infected red blood cells, suggesting that they are unlikely to be targets of surface variant-specific antibodies or to be directly involved in adhesion of infected red blood cells to host cells, as described for Plasmodium falciparum VAR proteins. The differences in subcellular localisation of the two major clades of Plasmodium chabaudi PIRs across the blood cycle, and the apparent lack of expression on the red cell surface strongly suggest that the function(s) of this gene family may differ from those of other multigene families of Plasmodium, such as the var genes of Plasmodium falciparum.
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Affiliation(s)
- Maria Giorgalli
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | | | - Malgorzata Broncel
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Aaron Sait
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Thomas E. Harrison
- Laboratory of Molecular Parasitology, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Caroline Hosking
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Audrey Vandomme
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Sarah I. Amis
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ana Antonello
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Lauren Sullivan
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Faith Uwadiae
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Laura Torella
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Matthew K. Higgins
- Laboratory of Molecular Parasitology, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Jean Langhorne
- Malaria Immunology Laboratory, The Francis Crick Institute, London, United Kingdom
- *Correspondence: Jean Langhorne,
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9
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Bahl V, Chaddha K, Mian SY, Holder AA, Knuepfer E, Gaur D. Genetic disruption of Plasmodium falciparum Merozoite surface antigen 180 (PfMSA180) suggests an essential role during parasite egress from erythrocytes. Sci Rep 2021; 11:19183. [PMID: 34584166 PMCID: PMC8479079 DOI: 10.1038/s41598-021-98707-0] [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: 03/11/2021] [Accepted: 09/02/2021] [Indexed: 11/16/2022] Open
Abstract
Plasmodium falciparum, the parasite responsible for severe malaria, develops within erythrocytes. Merozoite invasion and subsequent egress of intraerythrocytic parasites are essential for this erythrocytic cycle, parasite survival and pathogenesis. In the present study, we report the essential role of a novel protein, P. falciparum Merozoite Surface Antigen 180 (PfMSA180), which is conserved across Plasmodium species and recently shown to be associated with the P. vivax merozoite surface. Here, we studied MSA180 expression, processing, localization and function in P. falciparum blood stages. Initially we examined its role in invasion, a process mediated by multiple ligand-receptor interactions and an attractive step for targeting with inhibitory antibodies through the development of a malaria vaccine. Using antibodies specific for different regions of PfMSA180, together with a parasite containing a conditional pfmsa180-gene knockout generated using CRISPR/Cas9 and DiCre recombinase technology, we demonstrate that this protein is unlikely to play a crucial role in erythrocyte invasion. However, deletion of the pfmsa180 gene resulted in a severe egress defect, preventing schizont rupture and blocking the erythrocytic cycle. Our study highlights an essential role of PfMSA180 in parasite egress, which could be targeted through the development of a novel malaria intervention strategy.
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Affiliation(s)
- Vanndita Bahl
- Laboratory of Malaria and Vaccine Research, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Kritika Chaddha
- Laboratory of Malaria and Vaccine Research, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Syed Yusuf Mian
- Laboratory of Malaria and Vaccine Research, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Anthony A Holder
- Malaria Parasitology Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Ellen Knuepfer
- Malaria Parasitology Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK. .,The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, AL9 7TA, Hertfordshire, UK.
| | - Deepak Gaur
- Laboratory of Malaria and Vaccine Research, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
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10
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de Oliveira LS, Alborghetti MR, Carneiro RG, Bastos IMD, Amino R, Grellier P, Charneau S. Calcium in the Backstage of Malaria Parasite Biology. Front Cell Infect Microbiol 2021; 11:708834. [PMID: 34395314 PMCID: PMC8355824 DOI: 10.3389/fcimb.2021.708834] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/14/2021] [Indexed: 12/26/2022] Open
Abstract
The calcium ion (Ca2+) is a ubiquitous second messenger involved in key biological processes in prokaryotes and eukaryotes. In Plasmodium species, Ca2+ signaling plays a central role in the parasite life cycle. It has been associated with parasite development, fertilization, locomotion, and host cell infection. Despite the lack of a canonical inositol-1,4,5-triphosphate receptor gene in the Plasmodium genome, pharmacological evidence indicates that inositol-1,4,5-triphosphate triggers Ca2+ mobilization from the endoplasmic reticulum. Other structures such as acidocalcisomes, food vacuole and mitochondria are proposed to act as supplementary intracellular Ca2+ reservoirs. Several Ca2+-binding proteins (CaBPs) trigger downstream signaling. Other proteins with no EF-hand motifs, but apparently involved with CaBPs, are depicted as playing an important role in the erythrocyte invasion and egress. It is also proposed that a cross-talk among kinases, which are not members of the family of Ca2+-dependent protein kinases, such as protein kinases G, A and B, play additional roles mediated indirectly by Ca2+ regulation. This statement may be extended for proteins directly related to invasion or egress, such as SUB1, ERC, IMC1I, IMC1g, GAP45 and EBA175. In this review, we update our understanding of aspects of Ca2+-mediated signaling correlated to the developmental stages of the malaria parasite life cycle.
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Affiliation(s)
- Lucas Silva de Oliveira
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, Institute of Biology, University of Brasilia, Brasilia, Brazil
- UMR 7245 MCAM, Molécules de Communication et Adaptation des Micro-organismes, Muséum National d’Histoire Naturelle, CNRS, Équipe Parasites et Protistes Libres, Paris, France
| | - Marcos Rodrigo Alborghetti
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, Institute of Biology, University of Brasilia, Brasilia, Brazil
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Renata Garcia Carneiro
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, Institute of Biology, University of Brasilia, Brasilia, Brazil
| | - Izabela Marques Dourado Bastos
- Laboratory of Host-Pathogen Interaction, Department of Cell Biology, Institute of Biology, University of Brasilia, Brasilia, Brazil
| | - Rogerio Amino
- Unité Infection et Immunité Paludéennes, Institut Pasteur, Paris, France
| | - Philippe Grellier
- UMR 7245 MCAM, Molécules de Communication et Adaptation des Micro-organismes, Muséum National d’Histoire Naturelle, CNRS, Équipe Parasites et Protistes Libres, Paris, France
| | - Sébastien Charneau
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, Institute of Biology, University of Brasilia, Brasilia, Brazil
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11
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Tan MSY, Koussis K, Withers-Martinez C, Howell SA, Thomas JA, Hackett F, Knuepfer E, Shen M, Hall MD, Snijders AP, Blackman MJ. Autocatalytic activation of a malarial egress protease is druggable and requires a protein cofactor. EMBO J 2021; 40:e107226. [PMID: 33932049 PMCID: PMC8167364 DOI: 10.15252/embj.2020107226] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 03/11/2021] [Accepted: 03/23/2021] [Indexed: 12/21/2022] Open
Abstract
Malaria parasite egress from host erythrocytes (RBCs) is regulated by discharge of a parasite serine protease called SUB1 into the parasitophorous vacuole (PV). There, SUB1 activates a PV‐resident cysteine protease called SERA6, enabling host RBC rupture through SERA6‐mediated degradation of the RBC cytoskeleton protein β‐spectrin. Here, we show that the activation of Plasmodium falciparum SERA6 involves a second, autocatalytic step that is triggered by SUB1 cleavage. Unexpectedly, autoproteolytic maturation of SERA6 requires interaction in multimolecular complexes with a distinct PV‐located protein cofactor, MSA180, that is itself a SUB1 substrate. Genetic ablation of MSA180 mimics SERA6 disruption, producing a fatal block in β‐spectrin cleavage and RBC rupture. Drug‐like inhibitors of SERA6 autoprocessing similarly prevent β‐spectrin cleavage and egress in both P. falciparum and the emerging zoonotic pathogen P. knowlesi. Our results elucidate the egress pathway and identify SERA6 as a target for a new class of antimalarial drugs designed to prevent disease progression.
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Affiliation(s)
- Michele S Y Tan
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, UK
| | | | | | - Steven A Howell
- Protein Analysis and Proteomics Platform, The Francis Crick Institute, London, UK
| | - James A Thomas
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Fiona Hackett
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, UK
| | - Ellen Knuepfer
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hertfordshire, UK
| | - Min Shen
- National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, Rockville, MD, USA
| | - Matthew D Hall
- National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, Rockville, MD, USA
| | - Ambrosius P Snijders
- Protein Analysis and Proteomics Platform, The Francis Crick Institute, London, UK
| | - Michael J Blackman
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, UK.,Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
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12
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Abstract
All intracellular pathogens must escape (egress) from the confines of their host cell to disseminate and proliferate. The malaria parasite only replicates in an intracellular vacuole or in a cyst, and must undergo egress at four distinct phases during its complex life cycle, each time disrupting, in a highly regulated manner, the membranes or cyst wall that entrap the parasites. This Cell Science at a Glance article and accompanying poster summarises our current knowledge of the morphological features of egress across the Plasmodium life cycle, the molecular mechanisms that govern the process, and how researchers are working to exploit this knowledge to develop much-needed new approaches to malaria control. ![]()
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Affiliation(s)
- Michele S Y Tan
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Michael J Blackman
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London NW1 1AT, UK .,Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
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13
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Smith NA, Clarke OB, Lee M, Hodder AN, Smith BJ. Structure of the Plasmodium falciparum PfSERA5 pseudo-zymogen. Protein Sci 2020; 29:2245-2258. [PMID: 32955133 PMCID: PMC7586913 DOI: 10.1002/pro.3956] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/30/2022]
Abstract
PfSERA5, a significantly abundant protein present within the parasitophorous vacuole (PV) and essential for normal growth during the blood-stage life cycle of the malaria parasite Plasmodium falciparum, displays structural similarity to many other cysteine proteases. However, PfSERA5 does not exhibit any detectable protease activity and therefore the role of the PfSERA5 papain-like domain (PfSERA5E), thought to remain bound to its cognate prodomain, remains unknown. In this study, we present a revised structure of the central PfSERA5E domain at a resolution of 1.2 Å, and the first structure of the "zymogen" of this papain-like domain including its cognate prodomain (PfSERA5PE) to 2.2 Å resolution. PfSERA5PE is somewhat structurally similar to that of other known proenzymes, retaining the conserved overall folding and orientation of the prodomain through, and occluding, the archetypal papain-like catalytic triad "active-site" cleft, in the same reverse direction as conventional prodomains. Our findings are congruent with previously identified structures of PfSERA5E and of similar "zymogens" and provide a foundation for further investigation into the function of PfSERA5.
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Affiliation(s)
- Nicholas A. Smith
- Department of Chemistry and Physics, La Trobe Institute for Molecular ScienceLa Trobe UniversityMelbourneVictoriaAustralia
| | - Oliver B. Clarke
- Department of AnesthesiologyColumbia UniversityNew YorkNew YorkUSA
- Department of Physiology and Molecular BiophysicsColumbia UniversityNew YorkNew YorkUSA
| | - Mihwa Lee
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular ScienceLa Trobe UniversityMelbourneVictoriaAustralia
| | - Anthony N. Hodder
- The Walter and Eliza Hall Institute of Medical ResearchMelbourneVictoriaAustralia
| | - Brian J. Smith
- Department of Chemistry and Physics, La Trobe Institute for Molecular ScienceLa Trobe UniversityMelbourneVictoriaAustralia
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14
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A malaria parasite subtilisin propeptide-like protein is a potent inhibitor of the egress protease SUB1. Biochem J 2020; 477:525-540. [PMID: 31942933 PMCID: PMC6993865 DOI: 10.1042/bcj20190918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 12/23/2022]
Abstract
Subtilisin-like serine peptidases (subtilases) play important roles in the life cycle of many organisms, including the protozoan parasites that are the causative agent of malaria, Plasmodium spp. As with other peptidases, subtilase proteolytic activity has to be tightly regulated in order to prevent potentially deleterious uncontrolled protein degradation. Maturation of most subtilases requires the presence of an N-terminal propeptide that facilitates folding of the catalytic domain. Following its proteolytic cleavage, the propeptide acts as a transient, tightly bound inhibitor until its eventual complete removal to generate active protease. Here we report the identification of a stand-alone malaria parasite propeptide-like protein, called SUB1-ProM, encoded by a conserved gene that lies in a highly syntenic locus adjacent to three of the four subtilisin-like genes in the Plasmodium genome. Template-based modelling and ab initio structure prediction showed that the SUB1-ProM core structure is most similar to the X-ray crystal structure of the propeptide of SUB1, an essential parasite subtilase that is discharged into the parasitophorous vacuole (PV) to trigger parasite release (egress) from infected host cells. Recombinant Plasmodium falciparum SUB1-ProM was found to be a fast-binding, potent inhibitor of P. falciparum SUB1, but not of the only other essential blood-stage parasite subtilase, SUB2, or of other proteases examined. Mass-spectrometry and immunofluorescence showed that SUB1-ProM is expressed in the PV of blood stage P. falciparum, where it may act as an endogenous inhibitor to regulate SUB1 activity in the parasite.
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15
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Saunders CN, Cota E, Baum J, Tate EW. Peptide Probes for Plasmodium falciparum MyoA Tail Interacting Protein (MTIP): Exploring the Druggability of the Malaria Parasite Motor Complex. ACS Chem Biol 2020; 15:1313-1320. [PMID: 32383851 PMCID: PMC7309260 DOI: 10.1021/acschembio.0c00328] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
![]()
Malaria
remains an endemic tropical disease, and the emergence
of Plasmodium falciparum parasites resistant to current
front-line medicines means that new therapeutic targets are required.
The Plasmodium glideosome is a multiprotein complex
thought to be essential for efficient host red blood cell invasion.
At its core is a myosin motor, Myosin A (MyoA), which provides most
of the force required for parasite invasion. Here, we report the design
and development of improved peptide-based probes for the anchor point
of MyoA, the P. falciparum MyoA tail interacting
protein (PfMTIP). These probes combine low nanomolar
binding affinity with significantly enhanced cell penetration and
demonstrable competitive target engagement with native PfMTIP through a combination of Western blot and chemical proteomics.
These results provide new insights into the potential druggability
of the MTIP/MyoA interaction and a basis for the future design of
inhibitors.
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Affiliation(s)
| | - Ernesto Cota
- Department of Life Sciences, Imperial College, London SW7 2AZ, United Kingdom
| | - Jake Baum
- Department of Life Sciences, Imperial College, London SW7 2AZ, United Kingdom
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16
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Arisue N, Palacpac NMQ, Tougan T, Horii T. Characteristic features of the SERA multigene family in the malaria parasite. Parasit Vectors 2020; 13:170. [PMID: 32252804 PMCID: PMC7132891 DOI: 10.1186/s13071-020-04044-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/27/2020] [Indexed: 02/28/2023] Open
Abstract
Serine repeat antigen (SERA) is conserved among species of the genus Plasmodium. Sera genes form a multigene family and are generally tandemly clustered on a single chromosome. Although all Plasmodium species encode multiple sera genes, the number varies between species. Among species, the members share similar sequences and gene organization. SERA possess a central papain-like cysteine protease domain, however, in some members, the active site cysteine residue is substituted with a serine. Recent studies implicate this gene family in a number of aspects in parasite biology and induction of protective immune response. This review summarizes the current understanding on this important gene family in several Plasmodium species. The Plasmodium falciparum (Pf)-sera family, for example, consists of nine gene members. Unlike other multigene families in Plasmodium species, Pf-sera genes do not exhibit antigenic variation. Pf-sera5 nucleotide diversity is also low. Moreover, although Pf-sera5 is highly transcribed during the blood stage of malaria infection, and a large amount is released into the host blood following schizont rupture, in malaria endemic countries the sero-positive rates for Pf-SERA5 are low, likely due to Pf-SERA5 binding of host proteins to avoid immune recognition. As an antigen, the N-terminal 47 kDa domain of Pf-SERA5 is a promising vaccine candidate currently undergoing clinical trials. Pf-SERA5 and Pf-SERA6, as well as P. berghei (Pb)-SERA3, and Pb-SERA5, have been investigated for their roles in parasite egress. Two P. yoelii SERA, which have a serine residue at the protease active center, are implicated in parasite virulence. Overall, these studies provide insight that during the evolution of the Plasmodium parasite, the sera gene family members have increased by gene duplication, and acquired various functions that enable the parasite to survive and successfully maintain infection in the host.![]()
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Affiliation(s)
- Nobuko Arisue
- Research Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, 565-0871, Japan.
| | - Nirianne M Q Palacpac
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Takahiro Tougan
- Research Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, 565-0871, Japan
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17
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Dans MG, Weiss GE, Wilson DW, Sleebs BE, Crabb BS, de Koning-Ward TF, Gilson PR. Screening the Medicines for Malaria Venture Pathogen Box for invasion and egress inhibitors of the blood stage of Plasmodium falciparum reveals several inhibitory compounds. Int J Parasitol 2020; 50:235-252. [PMID: 32135179 DOI: 10.1016/j.ijpara.2020.01.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 12/30/2019] [Accepted: 01/05/2020] [Indexed: 12/14/2022]
Abstract
With emerging resistance to frontline treatments, it is vital that new drugs are identified to target Plasmodium falciparum. One of the most critical processes during parasites asexual lifecycle is the invasion and subsequent egress of red blood cells (RBCs). Many unique parasite ligands, receptors and enzymes are employed during egress and invasion that are essential for parasite proliferation and survival, therefore making these processes druggable targets. To identify potential inhibitors of egress and invasion, we screened the Medicines for Malaria Venture Pathogen Box, a 400 compound library against neglected tropical diseases, including 125 with antimalarial activity. For this screen, we utilised transgenic parasites expressing a bioluminescent reporter, nanoluciferase (Nluc), to measure inhibition of parasite egress and invasion in the presence of the Pathogen Box compounds. At a concentration of 2 µM, we found 15 compounds that inhibited parasite egress by >40% and 24 invasion-specific compounds that inhibited invasion by >90%. We further characterised 11 of these inhibitors through cell-based assays and live cell microscopy, and found two compounds that inhibited merozoite maturation in schizonts, one compound that inhibited merozoite egress, one compound that directly inhibited parasite invasion and one compound that slowed down invasion and arrested ring formation. The remaining compounds were general growth inhibitors that acted during the egress and invasion phase of the cell cycle. We found the sulfonylpiperazine, MMV020291, to be the most invasion-specific inhibitor, blocking successful merozoite internalisation within human RBCs and having no substantial effect on other stages of the cell cycle. This has significant implications for the possible development of an invasion-specific inhibitor as an antimalarial in a combination based therapy, in addition to being a useful tool for studying the biology of the invading parasite.
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Affiliation(s)
- Madeline G Dans
- Burnet Institute, Melbourne, Victoria 3004, Australia; School of Medicine, Deakin University, Waurn Ponds, Victoria 3216, Australia.
| | - Greta E Weiss
- Burnet Institute, Melbourne, Victoria 3004, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, The University of Adelaide, Adelaide, South Australia 5005, Australia; Burnet Institute, Melbourne, Victoria 3004, Australia
| | - Brad E Sleebs
- Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia; The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Brendan S Crabb
- Burnet Institute, Melbourne, Victoria 3004, Australia; The University of Melbourne, Parkville, Victoria 3010, Australia
| | | | - Paul R Gilson
- Burnet Institute, Melbourne, Victoria 3004, Australia.
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18
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Goldberg DE, Zimmerberg J. Hardly Vacuous: The Parasitophorous Vacuolar Membrane of Malaria Parasites. Trends Parasitol 2020; 36:138-146. [PMID: 31866184 PMCID: PMC6937376 DOI: 10.1016/j.pt.2019.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 12/30/2022]
Abstract
When a malaria parasite invades a host erythrocyte it pushes itself in and invaginates a portion of the host membrane, thereby sealing itself inside and establishing itself in the resulting vacuole. The parasitophorous vacuolar membrane (PVM) that surrounds the parasite is modified by the parasite, using its secretory organelles. To survive within this enveloping membrane, the organism must take in nutrients, secrete wastes, export proteins into the host cell, and eventually egress. Here, we review current understanding of the unique solutions Plasmodium has evolved to these challenges and discuss the remaining questions.
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Affiliation(s)
- Daniel E Goldberg
- Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St Louis, MO, USA.
| | - Joshua Zimmerberg
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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19
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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: 33] [Impact Index Per Article: 8.3] [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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20
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Host Cytoskeleton Remodeling throughout the Blood Stages of Plasmodium falciparum. Microbiol Mol Biol Rev 2019; 83:83/4/e00013-19. [PMID: 31484690 DOI: 10.1128/mmbr.00013-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The asexual intraerythrocytic development of Plasmodium falciparum, causing the most severe form of human malaria, is marked by extensive host cell remodeling. Throughout the processes of invasion, intracellular development, and egress, the erythrocyte membrane skeleton is remodeled by the parasite as required for each specific developmental stage. The remodeling is facilitated by a plethora of exported parasite proteins, and the erythrocyte membrane skeleton is the interface of most of the observed interactions between the parasite and host cell proteins. Host cell remodeling has been extensively described and there is a vast body of information on protein export or the description of parasite-induced structures such as Maurer's clefts or knobs on the host cell surface. Here we specifically review the molecular level of each host cell-remodeling step at each stage of the intraerythrocytic development of P. falciparum We describe key events, such as invasion, knob formation, and egress, and identify the interactions between exported parasite proteins and the host cell cytoskeleton. We discuss each remodeling step with respect to time and specific requirement of the developing parasite to explain host cell remodeling in a stage-specific manner. Thus, we highlight the interaction with the host membrane skeleton as a key event in parasite survival.
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21
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Pace T, Grasso F, Camarda G, Suarez C, Blackman MJ, Ponzi M, Olivieri A. The Plasmodium berghei serine protease PbSUB1 plays an important role in male gamete egress. Cell Microbiol 2019; 21:e13028. [PMID: 30941868 PMCID: PMC6766862 DOI: 10.1111/cmi.13028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 03/07/2019] [Accepted: 03/28/2019] [Indexed: 01/10/2023]
Abstract
The Plasmodium subtilisin-like serine protease SUB1 is expressed in hepatic and both asexual and sexual blood parasite stages. SUB1 is required for egress of invasive forms of the parasite from both erythrocytes and hepatocytes, but its subcellular localisation, function, and potential substrates in the sexual stages are unknown. Here, we have characterised the expression profile and subcellular localisation of SUB1 in Plasmodium berghei sexual stages. We show that the protease is selectively expressed in mature male gametocytes and localises to secretory organelles known to be involved in gamete egress, called male osmiophilic bodies. We have investigated PbSUB1 function in the sexual stages by generating P. berghei transgenic lines deficient in PbSUB1 expression or enzyme activity in gametocytes. Our results demonstrate that PbSUB1 plays a role in male gamete egress. We also show for the first time that the PbSUB1 substrate PbSERA3 is expressed in gametocytes and processed by PbSUB1 upon gametocyte activation. Taken together, our results strongly suggest that PbSUB1 is not only a promising drug target for asexual stages but could also be an attractive malaria transmission-blocking target.
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Affiliation(s)
- Tomasino Pace
- Dipartimento di Malattie InfettiveIstituto Superiore di SanitàRomeItaly
| | - Felicia Grasso
- Dipartimento di Malattie InfettiveIstituto Superiore di SanitàRomeItaly
| | - Grazia Camarda
- Dipartimento di Malattie InfettiveIstituto Superiore di SanitàRomeItaly
| | - Catherine Suarez
- Malaria Biochemistry LaboratoryThe Francis Crick InstituteLondonUK
| | - Michael J. Blackman
- Malaria Biochemistry LaboratoryThe Francis Crick InstituteLondonUK
- Faculty of Infectious and Tropical DiseasesLondon School of Hygiene and Tropical MedicineLondonUK
| | - Marta Ponzi
- Dipartimento di Malattie InfettiveIstituto Superiore di SanitàRomeItaly
| | - Anna Olivieri
- Dipartimento di Malattie InfettiveIstituto Superiore di SanitàRomeItaly
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22
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Kudyba HM, Cobb DW, Fierro MA, Florentin A, Ljolje D, Singh B, Lucchi NW, Muralidharan V. The endoplasmic reticulum chaperone PfGRP170 is essential for asexual development and is linked to stress response in malaria parasites. Cell Microbiol 2019; 21:e13042. [PMID: 31087747 PMCID: PMC6699899 DOI: 10.1111/cmi.13042] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 04/09/2019] [Accepted: 05/09/2019] [Indexed: 12/24/2022]
Abstract
The vast majority of malaria mortality is attributed to one parasite species: Plasmodium falciparum. Asexual replication of the parasite within the red blood cell is responsible for the pathology of the disease. In Plasmodium, the endoplasmic reticulum (ER) is a central hub for protein folding and trafficking as well as stress response pathways. In this study, we tested the role of an uncharacterised ER protein, PfGRP170, in regulating these key functions by generating conditional mutants. Our data show that PfGRP170 localises to the ER and is essential for asexual growth, specifically required for proper development of schizonts. PfGRP170 is essential for surviving heat shock, suggesting a critical role in cellular stress response. The data demonstrate that PfGRP170 interacts with the Plasmodium orthologue of the ER chaperone, BiP. Finally, we found that loss of PfGRP170 function leads to the activation of the Plasmodium eIF2α kinase, PK4, suggesting a specific role for this protein in this parasite stress response pathway.
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Affiliation(s)
- Heather M Kudyba
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia.,Department of Cellular Biology, University of Georgia, Athens, Georgia
| | - David W Cobb
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia.,Department of Cellular Biology, University of Georgia, Athens, Georgia
| | - Manuel A Fierro
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia.,Department of Cellular Biology, University of Georgia, Athens, Georgia
| | - Anat Florentin
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia
| | - Dragan Ljolje
- Malaria Branch and Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Balwan Singh
- Malaria Branch and Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Naomi W Lucchi
- Malaria Branch and Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Vasant Muralidharan
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia.,Department of Cellular Biology, University of Georgia, Athens, Georgia
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23
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Mishra M, Singh V, Singh S. Structural Insights Into Key Plasmodium Proteases as Therapeutic Drug Targets. Front Microbiol 2019; 10:394. [PMID: 30891019 PMCID: PMC6411711 DOI: 10.3389/fmicb.2019.00394] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/14/2019] [Indexed: 11/13/2022] Open
Abstract
Malaria, caused by protozoan of genus Plasmodium, remains one of the highest mortality infectious diseases. Malaria parasites have a complex life cycle, easily adapt to their host’s immune system and have evolved with an arsenal of unique proteases which play crucial roles in proliferation and survival within the host cells. Owing to the existing knowledge of enzymatic mechanisms, 3D structures and active sites of proteases, they have been proven to be opportune for target based drug development. Here, we discuss in depth the crucial roles of essential proteases in Plasmodium life cycle and particularly focus on highlighting the atypical “structural signatures” of key parasite proteases which have been exploited for drug development. These features, on one hand aid parasites pathogenicity while on the other hand could be effective in designing targeted and very specific inhibitors for counteracting them. We conclude that Plasmodium proteases are suitable as multistage targets for designing novel drugs with new modes of action to combat malaria.
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Affiliation(s)
- Manasi Mishra
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Dadri, India
| | - Vigyasa Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Shailja Singh
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Dadri, India.,Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
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24
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Flieger A, Frischknecht F, Häcker G, Hornef MW, Pradel G. Pathways of host cell exit by intracellular pathogens. MICROBIAL CELL 2018; 5:525-544. [PMID: 30533418 PMCID: PMC6282021 DOI: 10.15698/mic2018.12.659] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Host cell exit is a critical step in the life-cycle of intracellular pathogens, intimately linked to barrier penetration, tissue dissemination, inflammation, and pathogen transmission. Like cell invasion and intracellular survival, host cell exit represents a well-regulated program that has evolved during host-pathogen co-evolution and that relies on the dynamic and intricate interplay between multiple host and microbial factors. Three distinct pathways of host cell exit have been identified that are employed by three different taxa of intracellular pathogens, bacteria, fungi and protozoa, namely (i) the initiation of programmed cell death, (ii) the active breaching of host cellderived membranes, and (iii) the induced membrane-dependent exit without host cell lysis. Strikingly, an increasing number of studies show that the majority of intracellular pathogens utilize more than one of these strategies, dependent on life-cycle stage, environmental factors and/or host cell type. This review summarizes the diverse exit strategies of intracellular-living bacterial, fungal and protozoan pathogens and discusses the convergently evolved commonalities as well as system-specific variations thereof. Key microbial molecules involved in host cell exit are highlighted and discussed as potential targets for future interventional approaches.
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Affiliation(s)
- Antje Flieger
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | | | - Georg Häcker
- Institute of Medical Microbiology and Hygiene, Medical Center - University of Freiburg, Germany
| | - Mathias W Hornef
- Institute of Medical Microbiology, RWTH Aachen University Hospital, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Biology II, RWTH Aachen University, Germany
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25
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Armistead JS, Jennison C, O'Neill MT, Lopaticki S, Liehl P, Hanson KK, Annoura T, Rajasekaran P, Erickson SM, Tonkin CJ, Khan SM, Mota MM, Boddey JA. Plasmodium falciparum
subtilisin-like ookinete protein SOPT plays an important and conserved role during ookinete infection of the Anopheles stephensi
midgut. Mol Microbiol 2018; 109:458-473. [DOI: 10.1111/mmi.13993] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2018] [Indexed: 11/27/2022]
Affiliation(s)
- Jennifer S. Armistead
- The Walter and Eliza Hall Institute of Medical Research; Parkville 3052 Australia
- Department of Medical Biology; The University of Melbourne; Parkville 3052 Australia
| | - Charlie Jennison
- The Walter and Eliza Hall Institute of Medical Research; Parkville 3052 Australia
- Department of Medical Biology; The University of Melbourne; Parkville 3052 Australia
| | - Matthew T. O'Neill
- The Walter and Eliza Hall Institute of Medical Research; Parkville 3052 Australia
| | - Sash Lopaticki
- The Walter and Eliza Hall Institute of Medical Research; Parkville 3052 Australia
| | - Peter Liehl
- Instituto de Medicina Molecular, Faculdade de Medicina; Universidade de Lisboa; 1649-028 Lisbon Portugal
| | - Kirsten K. Hanson
- Instituto de Medicina Molecular, Faculdade de Medicina; Universidade de Lisboa; 1649-028 Lisbon Portugal
| | - Takeshi Annoura
- Leiden Malaria Research Group, Parasitology; Leiden University Medical Centre; 2333ZA Leiden the Netherlands
| | - Pravin Rajasekaran
- The Walter and Eliza Hall Institute of Medical Research; Parkville 3052 Australia
- Department of Medical Biology; The University of Melbourne; Parkville 3052 Australia
| | - Sara M. Erickson
- The Walter and Eliza Hall Institute of Medical Research; Parkville 3052 Australia
- Department of Medical Biology; The University of Melbourne; Parkville 3052 Australia
| | - Christopher J. Tonkin
- The Walter and Eliza Hall Institute of Medical Research; Parkville 3052 Australia
- Department of Medical Biology; The University of Melbourne; Parkville 3052 Australia
| | - Shahid M. Khan
- Leiden Malaria Research Group, Parasitology; Leiden University Medical Centre; 2333ZA Leiden the Netherlands
| | - Maria M. Mota
- Instituto de Medicina Molecular, Faculdade de Medicina; Universidade de Lisboa; 1649-028 Lisbon Portugal
| | - Justin A. Boddey
- The Walter and Eliza Hall Institute of Medical Research; Parkville 3052 Australia
- Department of Medical Biology; The University of Melbourne; Parkville 3052 Australia
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26
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Siqueira-Neto JL, Debnath A, McCall LI, Bernatchez JA, Ndao M, Reed SL, Rosenthal PJ. Cysteine proteases in protozoan parasites. PLoS Negl Trop Dis 2018; 12:e0006512. [PMID: 30138453 PMCID: PMC6107107 DOI: 10.1371/journal.pntd.0006512] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cysteine proteases (CPs) play key roles in the pathogenesis of protozoan parasites, including cell/tissue penetration, hydrolysis of host or parasite proteins, autophagy, and evasion or modulation of the host immune response, making them attractive chemotherapeutic and vaccine targets. This review highlights current knowledge on clan CA cysteine proteases, the best-characterized group of cysteine proteases, from 7 protozoan organisms causing human diseases with significant impact: Entamoeba histolytica, Leishmania species (sp.), Trypanosoma brucei, T. cruzi, Cryptosporidium sp., Plasmodium sp., and Toxoplasma gondii. Clan CA proteases from three organisms (T. brucei, T. cruzi, and Plasmodium sp.) are well characterized as druggable targets based on in vitro and in vivo models. A number of candidate inhibitors are under development. CPs from these organisms and from other protozoan parasites should be further characterized to improve our understanding of their biological functions and identify novel targets for chemotherapy.
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Affiliation(s)
- Jair L. Siqueira-Neto
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
| | - Anjan Debnath
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Laura-Isobel McCall
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Jean A. Bernatchez
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Momar Ndao
- National Reference Centre for Parasitology, The Research Institute of the McGill University Health Center, Montreal, Canada
- Program in Infectious Diseases and Immunity in Global Health, The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Sharon L. Reed
- Departments of Pathology and Medicine, University of California San Diego School of Medicine, La Jolla, California, United States of America
| | - Philip J. Rosenthal
- Department of Medicine, University of California, San Francisco, San Francisco, California, United States of America
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27
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Mathews ES, Odom John AR. Tackling resistance: emerging antimalarials and new parasite targets in the era of elimination. F1000Res 2018; 7. [PMID: 30135714 PMCID: PMC6073090 DOI: 10.12688/f1000research.14874.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/26/2018] [Indexed: 12/27/2022] Open
Abstract
Malaria remains a significant contributor to global human mortality, and roughly half the world’s population is at risk for infection with
Plasmodium spp. parasites. Aggressive control measures have reduced the global prevalence of malaria significantly over the past decade. However, resistance to available antimalarials continues to spread, including resistance to the widely used artemisinin-based combination therapies. Novel antimalarial compounds and therapeutic targets are greatly needed. This review will briefly discuss several promising current antimalarial development projects, including artefenomel, ferroquine, cipargamin, SJ733, KAF156, MMV048, and tafenoquine. In addition, we describe recent large-scale genetic and resistance screens that have been instrumental in target discovery. Finally, we highlight new antimalarial targets, which include essential transporters and proteases. These emerging antimalarial compounds and therapeutic targets have the potential to overcome multi-drug resistance in ongoing efforts toward malaria elimination.
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Affiliation(s)
- Emily S Mathews
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Audrey R Odom John
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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28
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Glushakova S, Beck JR, Garten M, Busse BL, Nasamu AS, Tenkova-Heuser T, Heuser J, Goldberg DE, Zimmerberg J. Rounding precedes rupture and breakdown of vacuolar membranes minutes before malaria parasite egress from erythrocytes. Cell Microbiol 2018; 20:e12868. [PMID: 29900649 DOI: 10.1111/cmi.12868] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 05/25/2018] [Accepted: 06/05/2018] [Indexed: 01/17/2023]
Abstract
Because Plasmodium falciparum replicates inside of a parasitophorous vacuole (PV) within a human erythrocyte, parasite egress requires the rupture of two limiting membranes. Parasite Ca2+ , kinases, and proteases contribute to efficient egress; their coordination in space and time is not known. Here, the kinetics of parasite egress were linked to specific steps with specific compartment markers, using live-cell microscopy of parasites expressing PV-targeted fluorescent proteins, and specific egress inhibitors. Several minutes before egress, under control of parasite [Ca2+ ]i , the PV began rounding. Then after ~1.5 min, under control of PfPKG and SUB1, there was abrupt rupture of the PV membrane and release of vacuolar contents. Over the next ~6 min, there was progressive vacuolar membrane deterioration simultaneous with erythrocyte membrane distortion, lasting until the final minute of the egress programme when newly formed parasites mobilised and erythrocyte membranes permeabilised and then ruptured-a dramatic finale to the parasite cycle of replication.
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Affiliation(s)
- Svetlana Glushakova
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Josh R Beck
- Division of Infectious Diseases, Department of Medicine, Washington University, St. Louis, Missouri.,Department of Biomedical Sciences, Iowa State University, Ames, Iowa
| | - Matthias Garten
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Brad L Busse
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Armiyaw S Nasamu
- Division of Infectious Diseases, Department of Medicine, Washington University, St. Louis, Missouri
| | - Tatyana Tenkova-Heuser
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - John Heuser
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Daniel E Goldberg
- Division of Infectious Diseases, Department of Medicine, Washington University, St. Louis, Missouri
| | - Joshua Zimmerberg
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
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29
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Lehmann C, Tan MSY, de Vries LE, Russo I, Sanchez MI, Goldberg DE, Deu E. Plasmodium falciparum dipeptidyl aminopeptidase 3 activity is important for efficient erythrocyte invasion by the malaria parasite. PLoS Pathog 2018; 14:e1007031. [PMID: 29768491 PMCID: PMC5973627 DOI: 10.1371/journal.ppat.1007031] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 05/29/2018] [Accepted: 04/15/2018] [Indexed: 11/19/2022] Open
Abstract
Parasite egress from infected erythrocytes and invasion of new red blood cells are essential processes for the exponential asexual replication of the malaria parasite. These two tightly coordinated events take place in less than a minute and are in part regulated and mediated by proteases. Dipeptidyl aminopeptidases (DPAPs) are papain-fold cysteine proteases that cleave dipeptides from the N-terminus of protein substrates. DPAP3 was previously suggested to play an essential role in parasite egress. However, little is known about its enzymatic activity, intracellular localization, or biological function. In this study, we recombinantly expressed DPAP3 and demonstrate that it has indeed dipeptidyl aminopeptidase activity, but contrary to previously studied DPAPs, removal of its internal prodomain is not required for activation. By combining super resolution microscopy, time-lapse fluorescence microscopy, and immunoelectron microscopy, we show that Plasmodium falciparum DPAP3 localizes to apical organelles that are closely associated with the neck of the rhoptries, and from which DPAP3 is secreted immediately before parasite egress. Using a conditional knockout approach coupled to complementation studies with wild type or mutant DPAP3, we show that DPAP3 activity is important for parasite proliferation and critical for efficient red blood cell invasion. We also demonstrate that DPAP3 does not play a role in parasite egress, and that the block in egress phenotype previously reported for DPAP3 inhibitors is due to off target or toxicity effects. Finally, using a flow cytometry assay to differentiate intracellular parasites from extracellular parasites attached to the erythrocyte surface, we show that DPAP3 is involved in the initial attachment of parasites to the red blood cell surface. Overall, this study establishes the presence of a DPAP3-dependent invasion pathway in malaria parasites.
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Affiliation(s)
- Christine Lehmann
- Chemical Biology Approaches to Malaria Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Michele Ser Ying Tan
- Chemical Biology Approaches to Malaria Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Laura E. de Vries
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Ilaria Russo
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Mateo I. Sanchez
- Department of Genetics, Stanford School of Medicine, Stanford, California, United States of America
| | - Daniel E. Goldberg
- Departments of Molecular Microbiology and Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Edgar Deu
- Chemical Biology Approaches to Malaria Laboratory, The Francis Crick Institute, London, United Kingdom
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30
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Toxoplasma gondii LCAT Primarily Contributes to Tachyzoite Egress. mSphere 2018; 3:mSphere00073-18. [PMID: 29507893 PMCID: PMC5830472 DOI: 10.1128/mspheredirect.00073-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 02/08/2018] [Indexed: 12/31/2022] Open
Abstract
Toxoplasma gondii is one of the most successful human pathogens, infecting an estimated 2.5 billion people across the globe. Pathogenesis seen during acute or reactivated toxoplasmosis has been closely tied to the parasite’s intracellular lytic life cycle, which culminates in an event called egress that results in the release of freshly replicated parasites from the infected host cell. Despite the highly destructive, cytolytic nature of this event and its downstream consequences, very little is known about how the parasite accomplishes this step. Previous work has suggested a role for a secreted phospholipase, LCAT, in Toxoplasma egress and roles in cell traversal and egress in the Plasmodium species orthologue. We confirm here that LCAT-deficient tachyzoites are unable to efficiently egress from infected monolayers, and we provide evidence that LCAT catalytic activity is required for its role in egress. Egress is a crucial phase of the Toxoplasma gondii intracellular lytic cycle. This is a process that drives inflammation and is strongly associated with the pathogenesis observed during toxoplasmosis. Despite the link between this process and virulence, little is known about egress on a mechanistic or descriptive level. Previously published work has suggested that a phospholipase, lecithin-cholesterol acyltransferase (LCAT), secreted from the parasite’s dense granules contributes to parasite growth, virulence, and egress. Here we present evidence from several independent mutant parasite lines confirming a role for LCAT in efficient egress, although no defects in growth or virulence were apparent. We also show via genetic complementation that the catalytic activity of LCAT is required for its role in parasite egress. This work solidifies the contribution of LCAT to egress of T. gondii tachyzoites. IMPORTANCEToxoplasma gondii is one of the most successful human pathogens, infecting an estimated 2.5 billion people across the globe. Pathogenesis seen during acute or reactivated toxoplasmosis has been closely tied to the parasite’s intracellular lytic life cycle, which culminates in an event called egress that results in the release of freshly replicated parasites from the infected host cell. Despite the highly destructive, cytolytic nature of this event and its downstream consequences, very little is known about how the parasite accomplishes this step. Previous work has suggested a role for a secreted phospholipase, LCAT, in Toxoplasma egress and roles in cell traversal and egress in the Plasmodium species orthologue. We confirm here that LCAT-deficient tachyzoites are unable to efficiently egress from infected monolayers, and we provide evidence that LCAT catalytic activity is required for its role in egress.
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31
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A protease cascade regulates release of the human malaria parasite Plasmodium falciparum from host red blood cells. Nat Microbiol 2018; 3:447-455. [PMID: 29459732 DOI: 10.1038/s41564-018-0111-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 01/11/2018] [Indexed: 01/03/2023]
Abstract
Malaria parasites replicate within a parasitophorous vacuole in red blood cells (RBCs). Progeny merozoites egress upon rupture of first the parasitophorous vacuole membrane (PVM), then poration and rupture of the RBC membrane (RBCM). Egress is protease-dependent 1 , but none of the effector molecules that mediate membrane rupture have been identified and it is unknown how sequential rupture of the two membranes is controlled. Minutes before egress, the parasite serine protease SUB1 is discharged into the parasitophorous vacuole2-6 where it cleaves multiple substrates2,5,7-9 including SERA6, a putative cysteine protease10-12. Here, we show that Plasmodium falciparum parasites lacking SUB1 undergo none of the morphological transformations that precede egress and fail to rupture the PVM. In contrast, PVM rupture and RBCM poration occur normally in SERA6-null parasites but RBCM rupture does not occur. Complementation studies show that SERA6 is an enzyme that requires processing by SUB1 to function. RBCM rupture is associated with SERA6-dependent proteolytic cleavage within the actin-binding domain of the major RBC cytoskeletal protein β-spectrin. We conclude that SUB1 and SERA6 play distinct, essential roles in a coordinated proteolytic cascade that enables sequential rupture of the two bounding membranes and culminates in RBCM disruption through rapid, precise, SERA6-mediated disassembly of the RBC cytoskeleton.
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32
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Kumar K, Srinivasan P, Nold MJ, Moch JK, Reiter K, Sturdevant D, Otto TD, Squires RB, Herrera R, Nagarajan V, Rayner JC, Porcella SF, Geromanos SJ, Haynes JD, Narum DL. Profiling invasive Plasmodium falciparum merozoites using an integrated omics approach. Sci Rep 2017; 7:17146. [PMID: 29215067 PMCID: PMC5719419 DOI: 10.1038/s41598-017-17505-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/22/2017] [Indexed: 02/06/2023] Open
Abstract
The symptoms of malaria are brought about by blood-stage parasites, which are established when merozoites invade human erythrocytes. Our understanding of the molecular events that underpin erythrocyte invasion remains hampered by the short-period of time that merozoites are invasive. To address this challenge, a Plasmodium falciparum gamma-irradiated long-lived merozoite (LLM) line was developed and investigated. Purified LLMs invaded erythrocytes by an increase of 10–300 fold compared to wild-type (WT) merozoites. Using an integrated omics approach, we investigated the basis for the phenotypic difference. Only a few single nucleotide polymorphisms within the P. falciparum genome were identified and only marginal differences were observed in the merozoite transcriptomes. By contrast, using label-free quantitative mass-spectrometry, a significant change in protein abundance was noted, of which 200 were proteins of unknown function. We determined the relative molar abundance of over 1100 proteins in LLMs and further characterized the major merozoite surface protein complex. A unique processed MSP1 intermediate was identified in LLM but not observed in WT suggesting that delayed processing may be important for the observed phenotype. This integrated approach has demonstrated the significant role of the merozoite proteome during erythrocyte invasion, while identifying numerous unknown proteins likely to be involved in invasion.
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Affiliation(s)
- Krishan Kumar
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Prakash Srinivasan
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, USA. .,Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | | | - J Kathleen Moch
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Karine Reiter
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Dan Sturdevant
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - R Burke Squires
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Raul Herrera
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Vijayaraj Nagarajan
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Julian C Rayner
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Stephen F Porcella
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | | | - J David Haynes
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA.
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33
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Sherling ES, van Ooij C. Host cell remodeling by pathogens: the exomembrane system in Plasmodium-infected erythrocytes. FEMS Microbiol Rev 2017; 40:701-21. [PMID: 27587718 PMCID: PMC5007283 DOI: 10.1093/femsre/fuw016] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2016] [Indexed: 12/22/2022] Open
Abstract
Malaria is caused by infection of erythrocytes by parasites of the genus Plasmodium. To survive inside erythrocytes, these parasites induce sweeping changes within the host cell, one of the most dramatic of which is the formation of multiple membranous compartments, collectively referred to as the exomembrane system. As an uninfected mammalian erythrocyte is devoid of internal membranes, the parasite must be the force and the source behind the formation of these compartments. Even though the first evidence of the presence these of internal compartments was obtained over a century ago, their functions remain mostly unclear, and in some cases completely unknown, and the mechanisms underlying their formation are still mysterious. In this review, we provide an overview of the different parts of the exomembrane system, describing the parasitophorous vacuole, the tubovesicular network, Maurer's clefts, the caveola-vesicle complex, J dots and other mobile compartments, and the small vesicles that have been observed in Plasmodium-infected cells. Finally, we combine the data into a simplified view of the exomembrane system and its relation to the alterations of the host erythrocyte. Plasmodium parasites remodel the host erythrocyte in various ways, including the formation of several membranous compartments, together referred to as the exomembrane system, within the erythrocyte cytosol that together are key to the sweeping changes in the host cell.
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Affiliation(s)
- Emma S Sherling
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London NW7 1AA, UK Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Christiaan van Ooij
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London NW7 1AA, UK
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34
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Deu E. Proteases as antimalarial targets: strategies for genetic, chemical, and therapeutic validation. FEBS J 2017; 284:2604-2628. [PMID: 28599096 PMCID: PMC5575534 DOI: 10.1111/febs.14130] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 04/29/2017] [Accepted: 06/06/2017] [Indexed: 01/17/2023]
Abstract
Malaria is a devastating parasitic disease affecting half of the world's population. The rapid emergence of resistance against new antimalarial drugs, including artemisinin-based therapies, has made the development of drugs with novel mechanisms of action extremely urgent. Proteases are enzymes proven to be well suited for target-based drug development due to our knowledge of their enzymatic mechanisms and active site structures. More importantly, Plasmodium proteases have been shown to be involved in a variety of pathways that are essential for parasite survival. However, pharmacological rather than target-based approaches have dominated the field of antimalarial drug development, in part due to the challenge of robustly validating Plasmodium targets at the genetic level. Fortunately, over the last few years there has been significant progress in the development of efficient genetic methods to modify the parasite, including several conditional approaches. This progress is finally allowing us not only to validate essential genes genetically, but also to study their molecular functions. In this review, I present our current understanding of the biological role proteases play in the malaria parasite life cycle. I also discuss how the recent advances in Plasmodium genetics, the improvement of protease-oriented chemical biology approaches, and the development of malaria-focused pharmacological assays, can be combined to achieve a robust biological, chemical and therapeutic validation of Plasmodium proteases as viable drug targets.
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Affiliation(s)
- Edgar Deu
- Chemical Biology Approaches to Malaria LaboratoryThe Francis Crick InstituteLondonUK
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35
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Collins CR, Hackett F, Atid J, Tan MSY, Blackman MJ. The Plasmodium falciparum pseudoprotease SERA5 regulates the kinetics and efficiency of malaria parasite egress from host erythrocytes. PLoS Pathog 2017; 13:e1006453. [PMID: 28683142 PMCID: PMC5500368 DOI: 10.1371/journal.ppat.1006453] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 06/07/2017] [Indexed: 02/06/2023] Open
Abstract
Egress of the malaria parasite Plasmodium falciparum from its host red blood cell is a rapid, highly regulated event that is essential for maintenance and completion of the parasite life cycle. Egress is protease-dependent and is temporally associated with extensive proteolytic modification of parasite proteins, including a family of papain-like proteins called SERA that are expressed in the parasite parasitophorous vacuole. Previous work has shown that the most abundant SERA, SERA5, plays an important but non-enzymatic role in asexual blood stages. SERA5 is extensively proteolytically processed by a parasite serine protease called SUB1 as well as an unidentified cysteine protease just prior to egress. However, neither the function of SERA5 nor the role of its processing is known. Here we show that conditional disruption of the SERA5 gene, or of both the SERA5 and related SERA4 genes simultaneously, results in a dramatic egress and replication defect characterised by premature host cell rupture and the failure of daughter merozoites to efficiently disseminate, instead being transiently retained within residual bounding membranes. SERA5 is not required for poration (permeabilization) or vesiculation of the host cell membrane at egress, but the premature rupture phenotype requires the activity of a parasite or host cell cysteine protease. Complementation of SERA5 null parasites by ectopic expression of wild-type SERA5 reversed the egress defect, whereas expression of a SERA5 mutant refractory to processing failed to rescue the phenotype. Our findings implicate SERA5 as an important regulator of the kinetics and efficiency of egress and suggest that proteolytic modification is required for SERA5 function. In addition, our study reveals that efficient egress requires tight control of the timing of membrane rupture. Malaria, a disease that kills hundreds of thousands of people each year, is caused by a single-celled parasite that grows in red blood cells of infected individuals. Following each round of parasite multiplication, the infected red cells are actively ruptured in a process called egress, releasing a new generation of parasites. Egress is essential for progression to clinical disease, but little is known about how it is controlled. In this work we set out to address the function in egress of a Plasmodium falciparum protein called SERA5, an abundant component of the vacuole in which the parasite grows. We show that parasites lacking SERA5 (or lacking both SERA5 and a closely-related protein called SERA4) undergo accelerated but defective egress in which the bounding vacuole and red cell membranes do not rupture properly. This impedes the escape and subsequent replication of the newly-developed parasites. We also show that modification of SERA5 by parasites proteases just prior to egress is important for SERA5 function. Our results show that SERA5 is a ‘negative regulator’ of egress, controlling the speed of the pathway that leads to disruption of the membranes surrounding the intracellular parasite. Our findings increase our understanding of the molecular mechanisms underlying malarial egress and show that efficient egress requires tight control of the timing of membrane rupture.
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Affiliation(s)
- Christine R. Collins
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Fiona Hackett
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Jonathan Atid
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Michele Ser Ying Tan
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Michael J. Blackman
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
- Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
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36
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Hale VL, Watermeyer JM, Hackett F, Vizcay-Barrena G, van Ooij C, Thomas JA, Spink MC, Harkiolaki M, Duke E, Fleck RA, Blackman MJ, Saibil HR. Parasitophorous vacuole poration precedes its rupture and rapid host erythrocyte cytoskeleton collapse in Plasmodium falciparum egress. Proc Natl Acad Sci U S A 2017; 114:3439-3444. [PMID: 28292906 PMCID: PMC5380091 DOI: 10.1073/pnas.1619441114] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In the asexual blood stages of malarial infection, merozoites invade erythrocytes and replicate within a parasitophorous vacuole to form daughter cells that eventually exit (egress) by sequential rupture of the vacuole and erythrocyte membranes. The current model is that PKG, a malarial cGMP-dependent protein kinase, triggers egress, activating malarial proteases and other effectors. Using selective inhibitors of either PKG or cysteine proteases to separately inhibit the sequential steps in membrane perforation, combined with video microscopy, electron tomography, electron energy loss spectroscopy, and soft X-ray tomography of mature intracellular Plasmodium falciparum parasites, we resolve intermediate steps in egress. We show that the parasitophorous vacuole membrane (PVM) is permeabilized 10-30 min before its PKG-triggered breakdown into multilayered vesicles. Just before PVM breakdown, the host red cell undergoes an abrupt, dramatic shape change due to the sudden breakdown of the erythrocyte cytoskeleton, before permeabilization and eventual rupture of the erythrocyte membrane to release the parasites. In contrast to the previous view of PKG-triggered initiation of egress and a gradual dismantling of the host erythrocyte cytoskeleton over the course of schizont development, our findings identify an initial step in egress and show that host cell cytoskeleton breakdown is restricted to a narrow time window within the final stages of egress.
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Affiliation(s)
- Victoria L Hale
- Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, London, WC1E 7HX, United Kingdom
| | - Jean M Watermeyer
- Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, London, WC1E 7HX, United Kingdom
| | - Fiona Hackett
- Francis Crick Institute, London, NW1 1AT, United Kingdom
| | - Gema Vizcay-Barrena
- Centre for Ultrastructural Imaging, Kings College London, London, SE1 9RT, United Kingdom
| | | | - James A Thomas
- Francis Crick Institute, London, NW1 1AT, United Kingdom
| | | | | | | | - Roland A Fleck
- Centre for Ultrastructural Imaging, Kings College London, London, SE1 9RT, United Kingdom
| | - Michael J Blackman
- Francis Crick Institute, London, NW1 1AT, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | - Helen R Saibil
- Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, London, WC1E 7HX, United Kingdom;
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Sherling ES, Knuepfer E, Brzostowski JA, Miller LH, Blackman MJ, van Ooij C. The Plasmodium falciparum rhoptry protein RhopH3 plays essential roles in host cell invasion and nutrient uptake. eLife 2017; 6. [PMID: 28252384 PMCID: PMC5365315 DOI: 10.7554/elife.23239] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 02/26/2017] [Indexed: 11/18/2022] Open
Abstract
Merozoites of the protozoan parasite responsible for the most virulent form of malaria, Plasmodium falciparum, invade erythrocytes. Invasion involves discharge of rhoptries, specialized secretory organelles. Once intracellular, parasites induce increased nutrient uptake by generating new permeability pathways (NPP) including a Plasmodium surface anion channel (PSAC). RhopH1/Clag3, one member of the three-protein RhopH complex, is important for PSAC/NPP activity. However, the roles of the other members of the RhopH complex in PSAC/NPP establishment are unknown and it is unclear whether any of the RhopH proteins play a role in invasion. Here we demonstrate that RhopH3, the smallest component of the complex, is essential for parasite survival. Conditional truncation of RhopH3 substantially reduces invasive capacity. Those mutant parasites that do invade are defective in nutrient import and die. Our results identify a dual role for RhopH3 that links erythrocyte invasion to formation of the PSAC/NPP essential for parasite survival within host erythrocytes. DOI:http://dx.doi.org/10.7554/eLife.23239.001 Malaria is a life-threatening disease that affects millions of people around the world. The parasites that cause malaria have a complex life cycle that involves infecting both mosquitoes and mammals, including humans. In humans, the parasites spend part of their life cycle inside red blood cells, which causes the symptoms of the disease. In order to survive and multiply, malaria parasites need to make the red blood cell more permeable so that it can absorb nutrients from the blood stream and get rid of the toxic waste products they generate. It remains unclear how the parasites do this, but previous research has shown that the parasites produce channel-like proteins that make red blood cells more permeable to nutrients. One of the proteins involved in this process forms part of a complex with two other proteins, called RhopH2 and RhopH3. It is not known what these other two proteins do, and whether they are necessary for creating the new nutrient channels. Sherling et al. studied the RhopH3 protein to see if it is required to make red blood cells more permeable. The experiments used a genetically modified version of the parasite, in which RhopH3 no longer interacted with the two other proteins. The findings show that RhopH3 has two important roles: first, parasites need it to invade the red blood cells, and second, parasites cannot get nutrients into the red blood cell without RhopH3. Most antimalarial drugs work by preventing parasite replication in red blood cells, but parasites are becoming increasingly resistant to these drugs. Understanding which proteins allow parasites to invade and grow within blood cells will further the development of new malaria medication. The next step will be to understand the molecular mechanisms by which RhopH3 promotes invasion and subsequently facilitates nutrient uptake, and will help researchers to explore its potential as a drug target. DOI:http://dx.doi.org/10.7554/eLife.23239.002
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Affiliation(s)
- Emma S Sherling
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom.,Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, United States
| | - Ellen Knuepfer
- Malaria Parasitology Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Joseph A Brzostowski
- Laboratory of Immunogenetics Imaging Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, United States
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, United States
| | - Michael J Blackman
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom.,Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christiaan van Ooij
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
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Das S, Hertrich N, Perrin AJ, Withers-Martinez C, Collins CR, Jones ML, Watermeyer JM, Fobes ET, Martin SR, Saibil HR, Wright GJ, Treeck M, Epp C, Blackman MJ. Processing of Plasmodium falciparum Merozoite Surface Protein MSP1 Activates a Spectrin-Binding Function Enabling Parasite Egress from RBCs. Cell Host Microbe 2016; 18:433-44. [PMID: 26468747 PMCID: PMC4608996 DOI: 10.1016/j.chom.2015.09.007] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/17/2015] [Accepted: 09/18/2015] [Indexed: 11/09/2022]
Abstract
The malaria parasite Plasmodium falciparum replicates within erythrocytes, producing progeny merozoites that are released from infected cells via a poorly understood process called egress. The most abundant merozoite surface protein, MSP1, is synthesized as a large precursor that undergoes proteolytic maturation by the parasite protease SUB1 just prior to egress. The function of MSP1 and its processing are unknown. Here we show that SUB1-mediated processing of MSP1 is important for parasite viability. Processing modifies the secondary structure of MSP1 and activates its capacity to bind spectrin, a molecular scaffold protein that is the major component of the host erythrocyte cytoskeleton. Parasites expressing an inefficiently processed MSP1 mutant show delayed egress, and merozoites lacking surface-bound MSP1 display a severe egress defect. Our results indicate that interactions between SUB1-processed merozoite surface MSP1 and the spectrin network of the erythrocyte cytoskeleton facilitate host erythrocyte rupture to enable parasite egress. Merozoite surface protein MSP1 processing is important for P. falciparum viability Proteolytic processing activates MSP1’s heparin and spectrin-binding functions The rate of MSP1 processing governs the kinetics of parasite egress Loss of parasite surface MSP1 results in a severe egress defect
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Affiliation(s)
- Sujaan Das
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Nadine Hertrich
- Department für Infektiologie, Parasitologie, Universitätsklinikum Heidelberg, D-69120 Heidelberg, Germany
| | - Abigail J Perrin
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1HH, UK
| | | | - Christine R Collins
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Matthew L Jones
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Jean M Watermeyer
- Department of Crystallography, Birkbeck College, London, WC1E 7HX, UK
| | - Elmar T Fobes
- Department für Infektiologie, Parasitologie, Universitätsklinikum Heidelberg, D-69120 Heidelberg, Germany
| | - Stephen R Martin
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Helen R Saibil
- Department of Crystallography, Birkbeck College, London, WC1E 7HX, UK
| | - Gavin J Wright
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1HH, UK
| | - Moritz Treeck
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK
| | - Christian Epp
- Department für Infektiologie, Parasitologie, Universitätsklinikum Heidelberg, D-69120 Heidelberg, Germany
| | - Michael J Blackman
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, NW7 1AA, UK; Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.
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Development and Application of a Simple Plaque Assay for the Human Malaria Parasite Plasmodium falciparum. PLoS One 2016; 11:e0157873. [PMID: 27332706 PMCID: PMC4917082 DOI: 10.1371/journal.pone.0157873] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/06/2016] [Indexed: 02/03/2023] Open
Abstract
Malaria is caused by an obligate intracellular protozoan parasite that replicates within and destroys erythrocytes. Asexual blood stages of the causative agent of the most virulent form of human malaria, Plasmodium falciparum, can be cultivated indefinitely in vitro in human erythrocytes, facilitating experimental analysis of parasite cell biology, biochemistry and genetics. However, efforts to improve understanding of the basic biology of this important pathogen and to develop urgently required new antimalarial drugs and vaccines, suffer from a paucity of basic research tools. This includes a simple means of quantifying the effects of drugs, antibodies and gene modifications on parasite fitness and replication rates. Here we describe the development and validation of an extremely simple, robust plaque assay that can be used to visualise parasite replication and resulting host erythrocyte destruction at the level of clonal parasite populations. We demonstrate applications of the plaque assay by using it for the phenotypic characterisation of two P. falciparum conditional mutants displaying reduced fitness in vitro.
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40
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Beeson JG, Drew DR, Boyle MJ, Feng G, Fowkes FJI, Richards JS. Merozoite surface proteins in red blood cell invasion, immunity and vaccines against malaria. FEMS Microbiol Rev 2016; 40:343-72. [PMID: 26833236 PMCID: PMC4852283 DOI: 10.1093/femsre/fuw001] [Citation(s) in RCA: 218] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2016] [Indexed: 01/11/2023] Open
Abstract
Malaria accounts for an enormous burden of disease globally, with Plasmodium falciparum accounting for the majority of malaria, and P. vivax being a second important cause, especially in Asia, the Americas and the Pacific. During infection with Plasmodium spp., the merozoite form of the parasite invades red blood cells and replicates inside them. It is during the blood-stage of infection that malaria disease occurs and, therefore, understanding merozoite invasion, host immune responses to merozoite surface antigens, and targeting merozoite surface proteins and invasion ligands by novel vaccines and therapeutics have been important areas of research. Merozoite invasion involves multiple interactions and events, and substantial processing of merozoite surface proteins occurs before, during and after invasion. The merozoite surface is highly complex, presenting a multitude of antigens to the immune system. This complexity has proved challenging to our efforts to understand merozoite invasion and malaria immunity, and to developing merozoite antigens as malaria vaccines. In recent years, there has been major progress in this field, and several merozoite surface proteins show strong potential as malaria vaccines. Our current knowledge on this topic is reviewed, highlighting recent advances and research priorities. The authors summarize current knowledge of merozoite surface proteins of malaria parasites; their function in invasion, processing of surface proteins before, during and after invasion, their importance as targets of immunity, and the current status of malaria vaccines that target merozoite surface proteins.
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Affiliation(s)
- James G Beeson
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia Department of Microbiology, Monash University, Clayton, Victoria, Australia Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Damien R Drew
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Michelle J Boyle
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Gaoqian Feng
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia
| | - Freya J I Fowkes
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia Department of Epidemiology and Preventive Medicine, Monash University, Clayton, Victoria, Australia School of Population Health, University of Melbourne, Parkville, Victoria, Australia
| | - Jack S Richards
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Melbourne, Victoria, Australia Department of Microbiology, Monash University, Clayton, Victoria, Australia Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
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41
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Draper SJ, Angov E, Horii T, Miller LH, Srinivasan P, Theisen M, Biswas S. Recent advances in recombinant protein-based malaria vaccines. Vaccine 2015; 33:7433-43. [PMID: 26458807 PMCID: PMC4687528 DOI: 10.1016/j.vaccine.2015.09.093] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 09/05/2015] [Accepted: 09/28/2015] [Indexed: 01/03/2023]
Abstract
Protein-based vaccines remain the cornerstone approach for B cell and antibody induction against leading target malaria antigens. Advances in antigen selection, immunogen design and epitope-focusing are advancing the field. New heterologous expression platforms are enabling cGMP production of next-generation protein vaccines. Next-generation antigens, protein-based immunogens and virus-like particle (VLP) delivery platforms are in clinical development. Protein-based vaccines will form part of a highly effective multi-component/multi-stage/multi-antigen subunit formulation against malaria.
Plasmodium parasites are the causative agent of human malaria, and the development of a highly effective vaccine against infection, disease and transmission remains a key priority. It is widely established that multiple stages of the parasite's complex lifecycle within the human host and mosquito vector are susceptible to vaccine-induced antibodies. The mainstay approach to antibody induction by subunit vaccination has been the delivery of protein antigen formulated in adjuvant. Extensive efforts have been made in this endeavor with respect to malaria vaccine development, especially with regard to target antigen discovery, protein expression platforms, adjuvant testing, and development of soluble and virus-like particle (VLP) delivery platforms. The breadth of approaches to protein-based vaccines is continuing to expand as innovative new concepts in next-generation subunit design are explored, with the prospects for the development of a highly effective multi-component/multi-stage/multi-antigen formulation seeming ever more likely. This review will focus on recent progress in protein vaccine design, development and/or clinical testing for a number of leading malaria antigens from the sporozoite-, merozoite- and sexual-stages of the parasite's lifecycle–including PfCelTOS, PfMSP1, PfAMA1, PfRH5, PfSERA5, PfGLURP, PfMSP3, Pfs48/45 and Pfs25. Future prospects and challenges for the development, production, human delivery and assessment of protein-based malaria vaccines are discussed.
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Affiliation(s)
- Simon J Draper
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK.
| | - Evelina Angov
- Walter Reed Army Institute of Research, U. S. Military Malaria Research Program, Malaria Vaccine Branch, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 561-873, Japan
| | - Louis H Miller
- Malaria Cell Biology Section, Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Prakash Srinivasan
- Malaria Cell Biology Section, Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark; Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology and Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Sumi Biswas
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK
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42
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McConville M, Fernández J, Angulo-Barturen Í, Bahamontes-Rosa N, Ballell-Pages L, Castañeda P, de Cózar C, Crespo B, Guijarro L, Jiménez-Díaz MB, Martínez-Martínez MS, de Mercado J, Santos-Villarejo Á, Sanz LM, Frigerio M, Washbourn G, Ward SA, Nixon GL, Biagini GA, Berry NG, Blackman MJ, Calderón F, O'Neill PM. Carbamoyl Triazoles, Known Serine Protease Inhibitors, Are a Potent New Class of Antimalarials. J Med Chem 2015. [PMID: 26222445 DOI: 10.1021/acs.jmedchem.5b00434] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Screening of the GSK corporate collection, some 1.9 million compounds, against Plasmodium falciparum (Pf), revealed almost 14000 active hits that are now known as the Tres Cantos Antimalarial Set (TCAMS). Followup work by Calderon et al. clustered and computationally filtered the TCAMS through a variety of criteria and reported 47 series containing a total of 522 compounds. From this enhanced set, we identified the carbamoyl triazole TCMDC-134379 (1), a known serine protease inhibitor, as an excellent starting point for SAR profiling. Lead optimization of 1 led to several molecules with improved antimalarial potency, metabolic stabilities in mouse and human liver microsomes, along with acceptable cytotoxicity profiles. Analogue 44 displayed potent in vitro activity (IC50 = 10 nM) and oral activity in a SCID mouse model of Pf infection with an ED50 of 100 and ED90 of between 100 and 150 mg kg(-1), respectively. The results presented encourage further investigations to identify the target of these highly active compounds.
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Affiliation(s)
- Matthew McConville
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Jorge Fernández
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Íñigo Angulo-Barturen
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Noemi Bahamontes-Rosa
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Lluis Ballell-Pages
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Pablo Castañeda
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Cristina de Cózar
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Benigno Crespo
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Laura Guijarro
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - María Belén Jiménez-Díaz
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Maria S Martínez-Martínez
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Jaime de Mercado
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Ángel Santos-Villarejo
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Laura M Sanz
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Micol Frigerio
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Gina Washbourn
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Stephen A Ward
- Liverpool School of Tropical Medicine , Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Gemma L Nixon
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Giancarlo A Biagini
- Liverpool School of Tropical Medicine , Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Neil G Berry
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Michael J Blackman
- Division of Parasitology, MRC National Institute for Medical Research , Mill Hill, London NW7 1AA, United Kingdom
| | - Félix Calderón
- Tres Cantos Medicines Development Campus, DDW, GlaxoSmithKline , Severo Ochoa 2, 28760 Tres Cantos, Spain
| | - Paul M O'Neill
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
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43
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Burda PC, Roelli MA, Schaffner M, Khan SM, Janse CJ, Heussler VT. A Plasmodium phospholipase is involved in disruption of the liver stage parasitophorous vacuole membrane. PLoS Pathog 2015; 11:e1004760. [PMID: 25786000 PMCID: PMC4364735 DOI: 10.1371/journal.ppat.1004760] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 02/22/2015] [Indexed: 11/18/2022] Open
Abstract
The coordinated exit of intracellular pathogens from host cells is a process critical to the success and spread of an infection. While phospholipases have been shown to play important roles in bacteria host cell egress and virulence, their role in the release of intracellular eukaryotic parasites is largely unknown. We examined a malaria parasite protein with phospholipase activity and found it to be involved in hepatocyte egress. In hepatocytes, Plasmodium parasites are surrounded by a parasitophorous vacuole membrane (PVM), which must be disrupted before parasites are released into the blood. However, on a molecular basis, little is known about how the PVM is ruptured. We show that Plasmodium berghei phospholipase, PbPL, localizes to the PVM in infected hepatocytes. We provide evidence that parasites lacking PbPL undergo completely normal liver stage development until merozoites are produced but have a defect in egress from host hepatocytes. To investigate this further, we established a live-cell imaging-based assay, which enabled us to study the temporal dynamics of PVM rupture on a quantitative basis. Using this assay we could show that PbPL-deficient parasites exhibit impaired PVM rupture, resulting in delayed parasite egress. A wild-type phenotype could be re-established by gene complementation, demonstrating the specificity of the PbPL deletion phenotype. In conclusion, we have identified for the first time a Plasmodium phospholipase that is important for PVM rupture and in turn for parasite exit from the infected hepatocyte and therefore established a key role of a parasite phospholipase in egress. Leaving their host cell is a crucial process for intracellular pathogens, allowing successful infection of other cells and thereby spreading of infection. Plasmodium parasites infect hepatocytes and red blood cells, and inside these cells they are contained within a vacuole like many other intracellular pathogens. Before parasites can infect other cells, the surrounding parasitophorous vacuole membrane (PVM) needs to be ruptured. However, little is known about this process on a molecular level and Plasmodium proteins mediating lysis of the PVM during parasite egress have not so far been identified. In this study, we characterize a Plasmodium phospholipase and show that it localizes to the PVM of parasites within hepatocytes. We demonstrate that parasites lacking this protein have a defect in rupture of the PVM and thereby in host cell egress. In conclusion, our study shows for the first time that a phospholipase plays a role in PVM disruption of an intracellular eukaryotic parasite.
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Affiliation(s)
- Paul-Christian Burda
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- Graduate School of Cellular Biology, University of Bern, Bern, Switzerland
- * E-mail:
| | | | - Marco Schaffner
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Shahid M. Khan
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Chris J. Janse
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
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44
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Stallmach R, Kavishwar M, Withers-Martinez C, Hackett F, Collins CR, Howell SA, Yeoh S, Knuepfer E, Atid AJ, Holder AA, Blackman MJ. Plasmodium falciparum SERA5 plays a non-enzymatic role in the malarial asexual blood-stage lifecycle. Mol Microbiol 2015; 96:368-87. [PMID: 25599609 PMCID: PMC4671257 DOI: 10.1111/mmi.12941] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2015] [Indexed: 02/02/2023]
Abstract
The malaria parasite Plasmodium falciparum replicates in an intraerythrocytic parasitophorous vacuole (PV). The most abundant P. falciparum PV protein, called SERA5, is essential in blood stages and possesses a papain-like domain, prompting speculation that it functions as a proteolytic enzyme. Unusually however, SERA5 possesses a Ser residue (Ser596) at the position of the canonical catalytic Cys of papain-like proteases, and the function of SERA5 or whether it performs an enzymatic role is unknown. In this study, we failed to detect proteolytic activity associated with the Ser596-containing parasite-derived or recombinant protein. However, substitution of Ser596 with a Cys residue produced an active recombinant enzyme with characteristics of a cysteine protease, demonstrating that SERA5 can bind peptides. Using targeted homologous recombination in P. falciparum, we substituted Ser596 with Ala with no phenotypic consequences, proving that SERA5 does not perform an essential enzymatic role in the parasite. We could also replace an internal segment of SERA5 with an affinity-purification tag. In contrast, using almost identical targeting constructs, we could not truncate or C-terminally tag the SERA5 gene, or replace Ser596 with a bulky Arg residue. Our findings show that SERA5 plays an indispensable but non-enzymatic role in the P. falciparum blood-stage life cycle.
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Affiliation(s)
- Robert Stallmach
- Division of Parasitology, MRC National Institute for Medical Research, London, NW7 1AA, UK
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45
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The malaria parasite egress protease SUB1 is a calcium-dependent redox switch subtilisin. Nat Commun 2014; 5:3726. [PMID: 24785947 PMCID: PMC4024747 DOI: 10.1038/ncomms4726] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/25/2014] [Indexed: 11/08/2022] Open
Abstract
Malaria is caused by a protozoan parasite that replicates within an intraerythrocytic parasitophorous vacuole. Release (egress) of malaria merozoites from the host erythrocyte is a highly regulated and calcium-dependent event that is critical for disease progression. Minutes before egress, an essential parasite serine protease called SUB1 is discharged into the parasitophorous vacuole, where it proteolytically processes a subset of parasite proteins that play indispensable roles in egress and invasion. Here we report the first crystallographic structure of Plasmodium falciparum SUB1 at 2.25 Å, in complex with its cognate prodomain. The structure highlights the basis of the calcium dependence of SUB1, as well as its unusual requirement for interactions with substrate residues on both prime and non-prime sides of the scissile bond. Importantly, the structure also reveals the presence of a solvent-exposed redox-sensitive disulphide bridge, unique among the subtilisin family, that likely acts as a regulator of protease activity in the parasite.
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Kanodia S, Kumar G, Rizzi L, Pedretti A, Hodder AN, Romeo S, Malhotra P. Synthetic peptides derived from the C-terminal 6kDa region of Plasmodium falciparum SERA5 inhibit the enzyme activity and malaria parasite development. Biochim Biophys Acta Gen Subj 2014; 1840:2765-75. [PMID: 24769454 DOI: 10.1016/j.bbagen.2014.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 03/21/2014] [Accepted: 04/15/2014] [Indexed: 11/27/2022]
Abstract
BACKGROUND Plasmodium falciparum serine repeat antigen 5 (PfSERA5) is an abundant blood stage protein that plays an essential role in merozoite egress and invasion. The native protein undergoes extensive proteolytic cleavage that appears to be tightly regulated. PfSERA5 N-terminal fragment is being developed as vaccine candidate antigen. Although PfSERA5 belongs to papain-like cysteine protease family, its catalytic domain has a serine in place of cysteine at the active site. METHODS In the present study, we synthesized a number of peptides from the N- and C-terminal regions of PfSERA5 active domain and evaluated their inhibitory potential. RESULTS The final proteolytic step of PfSERA5 involves removal of a C-terminal ~6kDa fragment that results in the generation of a catalytically active ~50kDa enzyme. In the present study, we demonstrate that two of the peptides derived from the C-terminal ~6kDa region inhibit the parasite growth and also cause a delay in the parasite development. These peptides reduced the enzyme activity of the recombinant protein and co-localized with the PfSERA5 protein within the parasite, thereby indicating the specific inhibition of PfSERA5 activity. Molecular docking studies revealed that the inhibitory peptides interact with the active site of the protein. Interestingly, the peptides did not have an effect on the processing of PfSERA5. CONCLUSIONS Our observations indicate the temporal regulation of the final proteolytic cleavage step that occurs just prior to egress. GENERAL SIGNIFICANCE These results reinforce the role of PfSERA5 for the intra-erythrocytic development of malaria parasite and show the role of carboxy terminal ~6kDa fragments in the regulation of PfSERA5 activity. The results also suggest that final cleavage step of PfSERA5 can be targeted for the development of new anti-malarials.
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Affiliation(s)
- Shivani Kanodia
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Gautam Kumar
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Luca Rizzi
- Dipartimento di Scienze Farmaceutiche, Facoltà di Scienze del Farmaco, Università degli Studi di Milano, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Alessandro Pedretti
- Dipartimento di Scienze Farmaceutiche, Facoltà di Scienze del Farmaco, Università degli Studi di Milano, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Anthony N Hodder
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia
| | - Sergio Romeo
- Dipartimento di Scienze Farmaceutiche, Facoltà di Scienze del Farmaco, Università degli Studi di Milano, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Pawan Malhotra
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
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Serine Proteases of Malaria Parasite Plasmodium falciparum: Potential as Antimalarial Drug Targets. Interdiscip Perspect Infect Dis 2014; 2014:453186. [PMID: 24799897 PMCID: PMC3988940 DOI: 10.1155/2014/453186] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 01/02/2014] [Accepted: 01/07/2014] [Indexed: 01/08/2023] Open
Abstract
Malaria is a major global parasitic disease and a cause of enormous mortality and morbidity. Widespread drug resistance against currently available antimalarials warrants the identification of novel drug targets and development of new drugs. Malarial proteases are a group of molecules that serve as potential drug targets because of their essentiality for parasite life cycle stages and feasibility of designing specific inhibitors against them. Proteases belonging to various mechanistic classes are found in P. falciparum, of which serine proteases are of particular interest due to their involvement in parasite-specific processes of egress and invasion. In P. falciparum, a number of serine proteases belonging to chymotrypsin, subtilisin, and rhomboid clans are found. This review focuses on the potential of P. falciparum serine proteases as antimalarial drug targets.
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Suarez C, Volkmann K, Gomes AR, Billker O, Blackman MJ. The malarial serine protease SUB1 plays an essential role in parasite liver stage development. PLoS Pathog 2013; 9:e1003811. [PMID: 24348254 PMCID: PMC3861531 DOI: 10.1371/journal.ppat.1003811] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 10/21/2013] [Indexed: 11/30/2022] Open
Abstract
Transmission of the malaria parasite to its vertebrate host involves an obligatory exoerythrocytic stage in which extensive asexual replication of the parasite takes place in infected hepatocytes. The resulting liver schizont undergoes segmentation to produce thousands of daughter merozoites. These are released to initiate the blood stage life cycle, which causes all the pathology associated with the disease. Whilst elements of liver stage merozoite biology are similar to those in the much better-studied blood stage merozoites, little is known of the molecular players involved in liver stage merozoite production. To facilitate the study of liver stage biology we developed a strategy for the rapid production of complex conditional alleles by recombinase mediated engineering in Escherichia coli, which we used in combination with existing Plasmodium berghei deleter lines expressing Flp recombinase to study subtilisin-like protease 1 (SUB1), a conserved Plasmodium serine protease previously implicated in blood stage merozoite maturation and egress. We demonstrate that SUB1 is not required for the early stages of intrahepatic growth, but is essential for complete development of the liver stage schizont and for production of hepatic merozoites. Our results indicate that inhibitors of SUB1 could be used in prophylactic approaches to control or block the clinically silent pre-erythrocytic stage of the malaria parasite life cycle. Malaria is caused by a single-celled parasite and is transmitted by the bite of an infected mosquito. The inoculated sporozoite forms of the parasite invade liver cells where they replicate, eventually releasing thousands of merozoites into the bloodstream to initiate the blood stage parasite life cycle which causes clinical malaria. The liver stage of the parasite life cycle is asymptomatic, so it is widely considered a potential target for prophylactic vaccine- or drug-based approaches designed to prevent infection. In this study, we use a robust, highly efficient gene engineering approach called recombineering, combined with a conditional gene deletion strategy to examine the function in liver stages of a parasite protease called SUB1, previously implicated in release of blood stage parasites. We show that SUB1 is expressed in the liver stage schizont and that the protease is essential for production of liver stage merozoites. Our results enhance our understanding of malarial liver stage biology, provide new tools for studying essential gene function in malaria, and suggest that inhibitors of SUB1 could be used as prophylactic drugs to prevent clinical malaria.
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Affiliation(s)
- Catherine Suarez
- Division of Parasitology, Medical Research Council National Institute for Medical Research, Mill Hill, London, United Kingdom
| | - Katrin Volkmann
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Ana Rita Gomes
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Oliver Billker
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
- * E-mail: (OB); (MJB)
| | - Michael J. Blackman
- Division of Parasitology, Medical Research Council National Institute for Medical Research, Mill Hill, London, United Kingdom
- * E-mail: (OB); (MJB)
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Tawk L, Lacroix C, Gueirard P, Kent R, Gorgette O, Thiberge S, Mercereau-Puijalon O, Ménard R, Barale JC. A key role for Plasmodium subtilisin-like SUB1 protease in egress of malaria parasites from host hepatocytes. J Biol Chem 2013; 288:33336-46. [PMID: 24089525 DOI: 10.1074/jbc.m113.513234] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In their mammalian host, Plasmodium parasites have two obligatory intracellular development phases, first in hepatocytes and subsequently in erythrocytes. Both involve an orchestrated process of invasion into and egress from host cells. The Plasmodium SUB1 protease plays a dual role at the blood stage by enabling egress of the progeny merozoites from the infected erythrocyte and priming merozoites for subsequent erythrocyte invasion. Here, using conditional mutagenesis in P. berghei, we show that SUB1 plays an essential role at the hepatic stage. Stage-specific sub1 invalidation during prehepatocytic development showed that SUB1-deficient parasites failed to rupture the parasitophorous vacuole membrane and to egress from hepatocytes. Furthermore, mechanically released parasites were not adequately primed and failed to establish a blood stage infection in vivo. The critical involvement of SUB1 in both pre-erythrocytic and erythrocytic developmental phases qualifies SUB1 as an attractive multistage target for prophylactic and therapeutic anti-Plasmodium intervention strategies.
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Affiliation(s)
- Lina Tawk
- From the Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, Département de Parasitologie et de Mycologie, F-75015 Paris, France
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Blackman MJ, Carruthers VB. Recent insights into apicomplexan parasite egress provide new views to a kill. Curr Opin Microbiol 2013; 16:459-64. [PMID: 23725669 PMCID: PMC3755044 DOI: 10.1016/j.mib.2013.04.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 04/23/2013] [Accepted: 04/25/2013] [Indexed: 01/20/2023]
Abstract
A hallmark of apicomplexan pathogens such as Plasmodium, Toxoplasma and Cryptosporidium is that they invade, replicate within, and then egress from their host cells. Egress usually results in lysis of the host cell, with deleterious consequences for the host. In the case of malaria, for example, much of the disease pathology is associated with cyclical waves of host erythrocyte destruction. This review highlights recent advances in mapping the signaling pathways that lead to egress and the parasite molecules involved in responding to and transmitting those signals. The review also discusses new findings for effector molecules that mediate disruption of the bounding membranes that enclose the intracellular parasite and the manner in which membrane rupture occurs to finally release invasive forms of the parasite.
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Affiliation(s)
- Michael J. Blackman
- Division of Parasitology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
| | - Vern B. Carruthers
- Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109-5620
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