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Charneau S, de Oliveira LS, Zenonos Z, Hopp CS, Bastos IMD, Loew D, Lombard B, Pandolfo Silveira A, de Carvalho Nardeli Basílio Lobo G, Bao SN, Grellier P, Rayner JC. APEX2-based proximity proteomic analysis identifies candidate interactors for Plasmodium falciparum knob-associated histidine-rich protein in infected erythrocytes. Sci Rep 2024; 14:11242. [PMID: 38755230 PMCID: PMC11099048 DOI: 10.1038/s41598-024-61295-w] [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: 12/19/2023] [Accepted: 05/03/2024] [Indexed: 05/18/2024] Open
Abstract
The interaction of Plasmodium falciparum-infected red blood cells (iRBCs) with the vascular endothelium plays a crucial role in malaria pathology and disease. KAHRP is an exported P. falciparum protein involved in iRBC remodelling, which is essential for the formation of protrusions or "knobs" on the iRBC surface. These knobs and the proteins that are concentrated within them allow the parasites to escape the immune response and host spleen clearance by mediating cytoadherence of the iRBC to the endothelial wall, but this also slows down blood circulation, leading in some cases to severe cerebral and placental complications. In this work, we have applied genetic and biochemical tools to identify proteins that interact with P. falciparum KAHRP using enhanced ascorbate peroxidase 2 (APEX2) proximity-dependent biotinylation and label-free shotgun proteomics. A total of 30 potential KAHRP-interacting candidates were identified, based on the assigned fragmented biotinylated ions. Several identified proteins have been previously reported to be part of the Maurer's clefts and knobs, where KAHRP resides. This study may contribute to a broader understanding of P. falciparum protein trafficking and knob architecture and shows for the first time the feasibility of using APEX2-proximity labelling in iRBCs.
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Affiliation(s)
- Sébastien Charneau
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, Institute of Biology, University of Brasília, Brasília, 70910-900, Brazil.
| | - Lucas Silva de Oliveira
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, Institute of Biology, University of Brasília, Brasília, 70910-900, Brazil
- UMR 7245 MCAM Molecules of Communication and Adaptation of Microorganisms, Muséum National d'Histoire Naturelle, CNRS, 75231, Paris Cedex 05, France
| | - Zenon Zenonos
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
- Biologics Engineering, Oncology R&D, AstraZenecaGranta Park, Cambridge, UK
| | - Christine S Hopp
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
- Protozoa Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Izabela M D Bastos
- Laboratory of Host Pathogen Interaction, Department of Cell Biology, Institute of Biology, University of Brasília, Brasília, 70910-900, Brazil
| | - Damarys Loew
- Institut Curie, Centre de Recherche, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d'Ulm, 75248, Paris Cedex 05, France
| | - Bérangère Lombard
- Institut Curie, Centre de Recherche, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d'Ulm, 75248, Paris Cedex 05, France
| | - Ariane Pandolfo Silveira
- Laboratory of Microscopy and Microanalysis, Department of Cell Biology, Institute of Biology, University of Brasilia, Brasília, 70910-900, Brazil
| | | | - Sônia Nair Bao
- Laboratory of Microscopy and Microanalysis, Department of Cell Biology, Institute of Biology, University of Brasilia, Brasília, 70910-900, Brazil
| | - Philippe Grellier
- UMR 7245 MCAM Molecules of Communication and Adaptation of Microorganisms, Muséum National d'Histoire Naturelle, CNRS, 75231, Paris Cedex 05, France
| | - Julian C Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge, CB2 0XY, UK
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2
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Shrikondawar AN, Chennoju K, Ghosh DK, Ranjan A. Identification and characterization of nuclear localization signals in the circumsporozoite protein of Plasmodium falciparum. FEBS Lett 2024; 598:801-817. [PMID: 38369616 DOI: 10.1002/1873-3468.14829] [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: 11/09/2023] [Revised: 12/30/2023] [Accepted: 01/15/2024] [Indexed: 02/20/2024]
Abstract
Secretory proteins of Plasmodium exhibit differential spatial and functional activity within the host cell nucleus. However, the nuclear localization signals (NLSs) for these proteins remain largely uncharacterized. In this study, we have identified and characterized two NLSs in the circumsporozoite protein of Plasmodium falciparum (Pf-CSP). Both NLSs in the Pf-CSP contain clusters of lysine and arginine residues essential for specific interactions with the conserved tryptophan and asparagine residues of importin-α, facilitating nuclear translocation of Pf-CSP. While the two NLSs of Pf-CSP function independently and are both crucial for nuclear localization, a single NLS of Pf-CSP leads to weak nuclear localization. These findings shed light on the mechanism of nuclear penetrability of secretory proteins of Plasmodium proteins.
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Affiliation(s)
- Akshaykumar Nanaji Shrikondawar
- Computational and Functional Genomics Group, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
- Graduate Studies, Regional Centre for Biotechnology, Faridabad, India
| | - Kiranmai Chennoju
- Computational and Functional Genomics Group, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
- Graduate Studies, Manipal Academy of Higher Education, Manipal, India
| | | | - Akash Ranjan
- Computational and Functional Genomics Group, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
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3
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Pitman EL, Counihan NA, Modak JK, Chowdury M, Gilson PR, Webb CT, de Koning-Ward TF. Dissecting EXP2 sequence requirements for protein export in malaria parasites. Front Cell Infect Microbiol 2024; 13:1332146. [PMID: 38282616 PMCID: PMC10811066 DOI: 10.3389/fcimb.2023.1332146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 12/19/2023] [Indexed: 01/30/2024] Open
Abstract
Apicomplexan parasites that reside within a parasitophorous vacuole harbor a conserved pore-forming protein that enables small-molecule transfer across the parasitophorous vacuole membrane (PVM). In Plasmodium parasites that cause malaria, this nutrient pore is formed by EXP2 which can complement the function of GRA17, an orthologous protein in Toxoplasma gondii. EXP2, however, has an additional function in Plasmodium parasites, serving also as the pore-forming component of the protein export machinery PTEX. To examine how EXP2 can play this additional role, transgenes that encoded truncations of EXP2, GRA17, hybrid GRA17-EXP2, or EXP2 under the transcriptional control of different promoters were expressed in EXP2 knockdown parasites to determine which could complement EXP2 function. This revealed that EXP2 is a unique pore-forming protein, and its protein export role in P. falciparum cannot be complemented by T. gondii GRA17. This was despite the addition of the EXP2 assembly strand and part of the linker helix to GRA17, which are regions necessary for the interaction of EXP2 with the other core PTEX components. This indicates that the body region of EXP2 plays a critical role in PTEX assembly and/or that the absence of other T. gondii GRA proteins in P. falciparum leads to its reduced efficiency of insertion into the PVM and complementation potential. Altering the timing and abundance of EXP2 expression did not affect protein export but affected parasite viability, indicating that the unique transcriptional profile of EXP2 when compared to other PTEX components enables it to serve an additional role in nutrient exchange.
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Affiliation(s)
- Ethan L. Pitman
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Natalie A. Counihan
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Joyanta K. Modak
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Mrittika Chowdury
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
| | - Paul R. Gilson
- Burnet Institute, Melbourne, VIC, Australia
- Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC, Australia
| | - Chaille T. Webb
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia
- Centre to Impact AMR, Monash University, Clayton, VIC, Australia
| | - Tania F. de Koning-Ward
- School of Medicine, Deakin University, Geelong, VIC, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, VIC, Australia
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4
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Gabriela M, Barnes CBG, Leong D, Sleebs BE, Schneider MP, Littler DR, Crabb BS, de Koning‐Ward TF, Gilson PR. Sequence elements within the PEXEL motif and its downstream region modulate PTEX-dependent protein export in Plasmodium falciparum. Traffic 2024; 25:e12922. [PMID: 37926971 PMCID: PMC10952997 DOI: 10.1111/tra.12922] [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: 03/23/2023] [Revised: 08/23/2023] [Accepted: 10/15/2023] [Indexed: 11/07/2023]
Abstract
The parasite Plasmodium falciparum causes the most severe form of malaria and to invade and replicate in red blood cells (RBCs), it exports hundreds of proteins across the encasing parasitophorous vacuole membrane (PVM) into this host cell. The exported proteins help modify the RBC to support rapid parasite growth and avoidance of the human immune system. Most exported proteins possess a conserved Plasmodium export element (PEXEL) motif with the consensus RxLxE/D/Q amino acid sequence, which acts as a proteolytic cleavage recognition site within the parasite's endoplasmic reticulum (ER). Cleavage occurs after the P1 L residue and is thought to help release the protein from the ER so it can be putatively escorted by the HSP101 chaperone to the parasitophorous vacuole space surrounding the intraerythrocytic parasite. HSP101 and its cargo are then thought to assemble with the rest of a Plasmodium translocon for exported proteins (PTEX) complex, that then recognises the xE/D/Q capped N-terminus of the exported protein and translocates it across the vacuole membrane into the RBC compartment. Here, we present evidence that supports a dual role for the PEXEL's conserved P2 ' position E/Q/D residue, first, for plasmepsin V cleavage in the ER, and second, for efficient PTEX mediated export across the PVM into the RBC. We also present evidence that the downstream 'spacer' region separating the PEXEL motif from the folded functional region of the exported protein controls cargo interaction with PTEX as well. The spacer must be of a sufficient length and permissive amino acid composition to engage the HSP101 unfoldase component of PTEX to be efficiently translocated into the RBC compartment.
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Affiliation(s)
- Mikha Gabriela
- Malaria Virulence and Drug Discovery GroupBurnet InstituteMelbourneVictoriaAustralia
- School of MedicineDeakin UniversityGeelongVictoriaAustralia
| | - Claudia B. G. Barnes
- Malaria Virulence and Drug Discovery GroupBurnet InstituteMelbourneVictoriaAustralia
| | - Dickson Leong
- Malaria Virulence and Drug Discovery GroupBurnet InstituteMelbourneVictoriaAustralia
| | - Brad E. Sleebs
- The Walter and Eliza Hall Institute of Medical ResearchParkvilleVictoriaAustralia
- Department of Medical BiologyThe University of MelbourneParkvilleVictoriaAustralia
| | | | - Dene R. Littler
- Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery InstituteMonash UniversityClaytonVictoriaAustralia
| | - Brendan S. Crabb
- Malaria Virulence and Drug Discovery GroupBurnet InstituteMelbourneVictoriaAustralia
- Department of Medical BiologyThe University of MelbourneParkvilleVictoriaAustralia
- Department of Microbiology and ImmunologyUniversity of MelbourneParkvilleVictoriaAustralia
- Department of ImmunologyMonash UniversityMelbourneVictoriaAustralia
| | - Tania F. de Koning‐Ward
- School of MedicineDeakin UniversityGeelongVictoriaAustralia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT)Deakin UniversityGeelongVictoriaAustralia
| | - Paul R. Gilson
- Malaria Virulence and Drug Discovery GroupBurnet InstituteMelbourneVictoriaAustralia
- Department of Microbiology and ImmunologyUniversity of MelbourneParkvilleVictoriaAustralia
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5
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Vallintine T, van Ooij C. Timing of dense granule biogenesis in asexual malaria parasites. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001389. [PMID: 37647112 PMCID: PMC10482371 DOI: 10.1099/mic.0.001389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 08/15/2023] [Indexed: 09/01/2023]
Abstract
Malaria is an important infectious disease that continues to claim hundreds of thousands of lives annually. The disease is caused by infection of host erythrocytes by apicomplexan parasites of the genus Plasmodium. The parasite contains three different apical organelles - micronemes, rhoptries and dense granules (DGs) - whose contents are secreted to mediate binding to and invasion of the host cell and the extensive remodelling of the host cell that occurs following invasion. Whereas the roles of micronemes and rhoptries in binding and invasion of the host erythrocyte have been studied in detail, the roles of DGs in Plasmodium parasites are poorly understood. They have been proposed to control host cell remodelling through regulated protein secretion after invasion, but many basic aspects of the biology of DGs remain unknown. Here we describe DG biogenesis timing for the first time, using RESA localization as a proxy for the timing of DG formation. We show that DG formation commences approximately 37 min prior to schizont egress, as measured by the recruitment of the DG marker RESA. Furthermore, using a bioinformatics approach, we aimed to predict additional cargo of the DGs and identified the J-dot protein HSP40 as a DG protein, further supporting the very early role of these organelles in the interaction of the parasite with the host cell.
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Affiliation(s)
- Tansy Vallintine
- Faculty of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Christiaan van Ooij
- Faculty of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
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Jonsdottir TK, Elsworth B, Cobbold S, Gabriela M, Ploeger E, Parkyn Schneider M, Charnaud SC, Dans MG, McConville M, Bullen HE, Crabb BS, Gilson PR. PTEX helps efficiently traffic haemoglobinases to the food vacuole in Plasmodium falciparum. PLoS Pathog 2023; 19:e1011006. [PMID: 37523385 PMCID: PMC10414648 DOI: 10.1371/journal.ppat.1011006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 08/10/2023] [Accepted: 07/16/2023] [Indexed: 08/02/2023] Open
Abstract
A key element of Plasmodium biology and pathogenesis is the trafficking of ~10% of the parasite proteome into the host red blood cell (RBC) it infects. To cross the parasite-encasing parasitophorous vacuole membrane, exported proteins utilise a channel-forming protein complex termed the Plasmodium translocon of exported proteins (PTEX). PTEX is obligatory for parasite survival, both in vitro and in vivo, suggesting that at least some exported proteins have essential metabolic functions. However, to date only one essential PTEX-dependent process, the new permeability pathways, has been described. To identify other essential PTEX-dependant proteins/processes, we conditionally knocked down the expression of one of its core components, PTEX150, and examined which pathways were affected. Surprisingly, the food vacuole mediated process of haemoglobin (Hb) digestion was substantially perturbed by PTEX150 knockdown. Using a range of transgenic parasite lines and approaches, we show that two major Hb proteases; falcipain 2a and plasmepsin II, interact with PTEX core components, implicating the translocon in the trafficking of Hb proteases. We propose a model where these proteases are translocated into the PV via PTEX in order to reach the cytostome, located at the parasite periphery, prior to food vacuole entry. This work offers a second mechanistic explanation for why PTEX function is essential for growth of the parasite within its host RBC.
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Affiliation(s)
- Thorey K. Jonsdottir
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Brendan Elsworth
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Simon Cobbold
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Australia
| | - Mikha Gabriela
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- School of Medicine, Deakin University, Geelong, Australia
| | - Ellen Ploeger
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | | | - Sarah C. Charnaud
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Madeline G. Dans
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Malcolm McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Australia
| | - Hayley E. Bullen
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Brendan S. Crabb
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
- Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Paul R. Gilson
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
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Ito D, Kondo Y, Takashima E, Iriko H, Thongkukiatkul A, Torii M, Otsuki H. Roles of the RON3 C-terminal fragment in erythrocyte invasion and blood-stage parasite proliferation in Plasmodium falciparum. Front Cell Infect Microbiol 2023; 13:1197126. [PMID: 37457963 PMCID: PMC10340547 DOI: 10.3389/fcimb.2023.1197126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/15/2023] [Indexed: 07/18/2023] Open
Abstract
Plasmodium species cause malaria, and in the instance of Plasmodium falciparum is responsible for a societal burden of over 600,000 deaths annually. The symptoms and pathology of malaria are due to intraerythocytic parasites. Erythrocyte invasion is mediated by the parasite merozoite stage, and is accompanied by the formation of a parasitophorous vacuolar membrane (PVM), within which the parasite develops. The merozoite apical rhoptry organelle contains various proteins that contribute to erythrocyte attachment and invasion. RON3, a rhoptry bulb membrane protein, undergoes protein processing and is discharged into the PVM during invasion. RON3-deficient parasites fail to develop beyond the intraerythrocytic ring stage, and protein export into erythrocytes by the Plasmodium translocon of exported proteins (PTEX) apparatus is abrogated, as well as glucose uptake into parasites. It is known that truncated N- and C-terminal RON3 fragments are present in rhoptries, but it is unclear which RON3 fragments contribute to protein export by PTEX and glucose uptake through the PVM. To investigate and distinguish the roles of the RON3 C-terminal fragment at distinct developmental stages, we used a C-terminus tag for conditional and post-translational control. We demonstrated that RON3 is essential for blood-stage parasite survival, and knockdown of RON3 C-terminal fragment expression from the early schizont stage induces a defect in erythrocyte invasion and the subsequent development of ring stage parasites. Protein processing of full-length RON3 was partially inhibited in the schizont stage, and the RON3 C-terminal fragment was abolished in subsequent ring-stage parasites compared to the RON3 N-terminal fragment. Protein export and glucose uptake were abrogated specifically in the late ring stage. Plasmodial surface anion channel (PSAC) activity was partially retained, facilitating small molecule traffic across the erythrocyte membrane. The knockdown of the RON3 C-terminal fragment after erythrocyte invasion did not alter parasite growth. These data suggest that the RON3 C-terminal fragment participates in erythrocyte invasion and serves an essential role in the progression of ring-stage parasite growth by the establishment of the nutrient-permeable channel in the PVM, accompanying the transport of ring-stage parasite protein from the plasma membrane to the PVM.
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Affiliation(s)
- Daisuke Ito
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Yoko Kondo
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Hideyuki Iriko
- Division of Global Infectious Diseases, Department of Public Health, Graduate School of Health Sciences, Kobe University, Kobe, Japan
| | | | - Motomi Torii
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Japan
| | - Hitoshi Otsuki
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
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Parkyn Schneider M, Looker O, Rebelo M, Khoury DS, Dixon MWA, Oeuvray C, Crabb BS, McCarthy J, Gilson PR. The delayed bloodstream clearance of Plasmodium falciparum parasites after M5717 treatment is attributable to the inability to modify their red blood cell hosts. Front Cell Infect Microbiol 2023; 13:1211613. [PMID: 37457953 PMCID: PMC10340534 DOI: 10.3389/fcimb.2023.1211613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 06/14/2023] [Indexed: 07/18/2023] Open
Abstract
M5717 is a promising antimalarial drug under development that acts against multiple stages of the life cycle of Plasmodium parasites by inhibiting the translation elongation factor 2 (PfeEF2), thereby preventing protein synthesis. The parasite clearance profile after drug treatment in preclinical studies in mice, and clinical trials in humans showed a notable delayed clearance phenotype whereby parasite infected red blood cells (iRBCs) persisted in the bloodstream for a significant period before eventual clearance. In a normal P. falciparum infection iRBCs sequester in the deep circulation by cytoadherence, allowing them to avoid surveillance and clearance in the spleen. We found that M5717 blocks parasite modification of their host red blood cells (RBCs) by preventing synthesis of new exported proteins, rather than by directly blocking the export of these proteins into the RBC compartment. Using in vitro models, we demonstrated that M5717 treated ring/trophozoite stage iRBCs became less rigid, and cytoadhered less well compared to untreated iRBCs. This indicates that in vivo persistence of M5717 treated iRBCs in the bloodstream is likely due to reduced cytoadherence and splenic clearance.
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Affiliation(s)
| | | | - Maria Rebelo
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - David S. Khoury
- Kirby Institute, University of New South Wales, Sydney, NSW, Australia
| | | | | | - Brendan S. Crabb
- Burnet Institute, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
- Monash University, Melbourne, VIC, Australia
| | | | - Paul R. Gilson
- Burnet Institute, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
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9
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Sulyman AO, Aje OO, Ajani EO, Abdulsalam RA, Balogun FO, Sabiu S. Bioprospection of Selected Plant Secondary Metabolites as Modulators of the Proteolytic Activity of Plasmodium falciparum Plasmepsin V. BIOMED RESEARCH INTERNATIONAL 2023; 2023:6229503. [PMID: 37388365 PMCID: PMC10307063 DOI: 10.1155/2023/6229503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/25/2023] [Accepted: 06/01/2023] [Indexed: 07/01/2023]
Abstract
Malaria is a devastating disease, and its management is only achieved through chemotherapy. However, resistance to available medication is still a challenge; therefore, there is an urgent need for the discovery and development of therapeutics with a novel mechanism of action to counter the resistance scourge consistent with the currently available antimalarials. Recently, plasmepsin V was validated as a therapeutic target for the treatment of malaria. The pepsin-like aspartic protease anchored in the endoplasmic reticulum is responsible for the trafficking of parasite-derived proteins to the erythrocytic surface of the host cells. In this study, a small library of compounds was preliminarily screened in vitro to identify novel modulators of Plasmodium falciparum plasmepsin V (PfPMV). The results obtained revealed kaempferol, quercetin, and shikonin as possible PfPMV inhibitors, and these compounds were subsequently probed for their inhibitory potentials using in vitro and in silico methods. Kaempferol and shikonin noncompetitively and competitively inhibited the specific activity of PfPMV in vitro with IC50 values of 22.4 and 43.34 μM, respectively, relative to 62.6 μM obtained for pepstatin, a known aspartic protease inhibitor. Further insight into the structure-activity relationship of the compounds through a 100 ns molecular dynamic (MD) simulation showed that all the test compounds had a significant affinity for PfPMV, with quercetin (-36.56 kcal/mol) being the most prominent metabolite displaying comparable activity to pepstatin (-35.72 kcal/mol). This observation was further supported by the compactness and flexibility of the resulting complexes where the compounds do not compromise the structural integrity of PfPMV but rather stabilized and interacted with the active site amino acid residues critical to PfPMV modulation. Considering the findings in this study, quercetin, kaempferol, and shikonin could be proposed as novel aspartic protease inhibitors worthy of further investigation in the treatment of malaria.
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Affiliation(s)
- Abdulhakeem Olarewaju Sulyman
- Department of Biochemistry, Faculty of Pure and Applied Sciences, Kwara State University, P.M.B. 1530, Malete, Ilorin, Nigeria
| | - Oluwapelumi Oluwaseun Aje
- Department of Biochemistry, Faculty of Pure and Applied Sciences, Kwara State University, P.M.B. 1530, Malete, Ilorin, Nigeria
| | - Emmanuel Oladipo Ajani
- Department of Biochemistry, Faculty of Pure and Applied Sciences, Kwara State University, P.M.B. 1530, Malete, Ilorin, Nigeria
| | - Rukayat Abiola Abdulsalam
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, Durban, South Africa
| | - Fatai Oladunni Balogun
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, Durban, South Africa
| | - Saheed Sabiu
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, Durban, South Africa
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10
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Reers AB, Bautista R, McLellan J, Morales B, Garza R, Bol S, Hanson KK, Bunnik EM. Histone modification analysis reveals common regulators of gene expression in liver and blood stage merozoites of Plasmodium parasites. Epigenetics Chromatin 2023; 16:25. [PMID: 37322481 PMCID: PMC10268464 DOI: 10.1186/s13072-023-00500-y] [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: 03/23/2023] [Accepted: 06/06/2023] [Indexed: 06/17/2023] Open
Abstract
Gene expression in malaria parasites is subject to various layers of regulation, including histone post-translational modifications (PTMs). Gene regulatory mechanisms have been extensively studied during the main developmental stages of Plasmodium parasites inside erythrocytes, from the ring stage following invasion to the schizont stage leading up to egress. However, gene regulation in merozoites that mediate the transition from one host cell to the next is an understudied area of parasite biology. Here, we sought to characterize gene expression and the corresponding histone PTM landscape during this stage of the parasite lifecycle through RNA-seq and ChIP-seq on P. falciparum blood stage schizonts, merozoites, and rings, as well as P. berghei liver stage merozoites. In both hepatic and erythrocytic merozoites, we identified a subset of genes with a unique histone PTM profile characterized by a region of H3K4me3 depletion in their promoter. These genes were upregulated in hepatic and erythrocytic merozoites and rings, had roles in protein export, translation, and host cell remodeling, and shared a DNA motif. These results indicate that similar regulatory mechanisms may underlie merozoite formation in the liver and blood stages. We also observed that H3K4me2 was deposited in gene bodies of gene families encoding variant surface antigens in erythrocytic merozoites, which may facilitate switching of gene expression between different members of these families. Finally, H3K18me and H2K27me were uncoupled from gene expression and were enriched around the centromeres in erythrocytic schizonts and merozoites, suggesting potential roles in the maintenance of chromosomal organization during schizogony. Together, our results demonstrate that extensive changes in gene expression and histone landscape occur during the schizont-to-ring transition to facilitate productive erythrocyte infection. The dynamic remodeling of the transcriptional program in hepatic and erythrocytic merozoites makes this stage attractive as a target for novel anti-malarial drugs that may have activity against both the liver and blood stages.
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Affiliation(s)
- Ashley B Reers
- Department of Microbiology, Immunology, and Molecular Genetics, Long School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA
| | - Rodriel Bautista
- Department of Microbiology, Immunology, and Molecular Genetics, Long School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA
| | - James McLellan
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas San Antonio, San Antonio, TX, USA
| | - Beatriz Morales
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas San Antonio, San Antonio, TX, USA
| | - Rolando Garza
- Department of Microbiology, Immunology, and Molecular Genetics, Long School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA
| | - Sebastiaan Bol
- Department of Microbiology, Immunology, and Molecular Genetics, Long School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA
| | - Kirsten K Hanson
- Department of Molecular Microbiology and Immunology and South Texas Center for Emerging Infectious Diseases, University of Texas San Antonio, San Antonio, TX, USA
| | - Evelien M Bunnik
- Department of Microbiology, Immunology, and Molecular Genetics, Long School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA.
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11
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Jeninga MD, Tang J, Selvarajah SA, Maier AG, Duffy MF, Petter M. Plasmodium falciparum gametocytes display global chromatin remodelling during sexual differentiation. BMC Biol 2023; 21:65. [PMID: 37013531 PMCID: PMC10071754 DOI: 10.1186/s12915-023-01568-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
BACKGROUND The protozoan malaria parasite Plasmodium falciparum has a complex life cycle during which it needs to differentiate into multiple morphologically distinct life forms. A key process for transmission of the disease is the development of male and female gametocytes in the human blood, yet the mechanisms determining sexual dimorphism in these haploid, genetically identical sexual precursor cells remain largely unknown. To understand the epigenetic program underlying the differentiation of male and female gametocytes, we separated the two sexual forms by flow cytometry and performed RNAseq as well as comprehensive ChIPseq profiling of several histone variants and modifications. RESULTS We show that in female gametocytes the chromatin landscape is globally remodelled with respect to genome-wide patterns and combinatorial usage of histone variants and histone modifications. We identified sex specific differences in heterochromatin distribution, implicating exported proteins and ncRNAs in sex determination. Specifically in female gametocytes, the histone variants H2A.Z/H2B.Z were highly enriched in H3K9me3-associated heterochromatin. H3K27ac occupancy correlated with stage-specific gene expression, but in contrast to asexual parasites this was unlinked to H3K4me3 co-occupancy at promoters in female gametocytes. CONCLUSIONS Collectively, we defined novel combinatorial chromatin states differentially organising the genome in gametocytes and asexual parasites and unravelled fundamental, sex-specific differences in the epigenetic code. Our chromatin maps represent an important resource for future understanding of the mechanisms driving sexual differentiation in P. falciparum.
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Affiliation(s)
- Myriam D Jeninga
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Jingyi Tang
- Department of Medicine, University of Melbourne, Bio21 Institute, 30 Flemington Road, Parkville, VIC, 3052, Australia
| | - Shamista A Selvarajah
- Department of Medicine, University of Melbourne, Bio21 Institute, 30 Flemington Road, Parkville, VIC, 3052, Australia
| | - Alexander G Maier
- The Australian National University, Research School of Biology, 134 Linnaeus Way, Canberra, ACT, 2601, Australia
| | - Michael F Duffy
- Department of Microbiology and Immunology, University of Melbourne, Peter Doherty Institute, 792 Elizabeth Street, Melbourne, VIC, 3000, Australia
- Bio21 Institute, 30 Flemington Road, Parkville, VIC, 3052, Australia
| | - Michaela Petter
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany.
- Department of Medicine, University of Melbourne, Bio21 Institute, 30 Flemington Road, Parkville, VIC, 3052, Australia.
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12
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Griffith MB, Pearce CS, Heaslip AT. Dense granule biogenesis, secretion, and function in Toxoplasma gondii. J Eukaryot Microbiol 2022; 69:e12904. [PMID: 35302693 PMCID: PMC9482668 DOI: 10.1111/jeu.12904] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite and the causative agent of Toxoplasmosis. A key to understanding and treating the disease lies with determining how the parasite can survive and replicate within cells of its host. Proteins released from specialized secretory vesicles, named the dense granules (DGs), have diverse functions that are critical for adapting the intracellular environment, and are thus key to survival and pathogenicity. In this review, we describe the current understanding and outstanding questions regarding dense granule biogenesis, trafficking, and regulation of secretion. In addition, we provide an overview of dense granule protein ("GRA") function upon secretion, with a focus on proteins that have recently been identified.
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Affiliation(s)
- Michael B Griffith
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Camille S Pearce
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Aoife T Heaslip
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
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13
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A member of the tryptophan-rich protein family is required for efficient sequestration of Plasmodium berghei schizonts. PLoS Pathog 2022; 18:e1010846. [PMID: 36126089 PMCID: PMC9524624 DOI: 10.1371/journal.ppat.1010846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/30/2022] [Accepted: 08/31/2022] [Indexed: 11/20/2022] Open
Abstract
Protein export and host membrane remodeling are crucial for multiple Plasmodium species to establish a niche in infected hosts. To better understand the contribution of these processes to successful parasite infection in vivo, we sought to find and characterize protein components of the intraerythrocytic Plasmodium berghei-induced membrane structures (IBIS) that form in the cytoplasm of infected erythrocytes. We identified proteins that immunoprecipitate with IBIS1, a signature member of the IBIS in P. berghei-infected erythrocytes. In parallel, we also report our data describing proteins that co-precipitate with the PTEX (Plasmodium translocon of exported proteins) component EXP2. To validate our findings, we examined the location of three candidate IBIS1-interactors that are conserved across multiple Plasmodium species, and we found they localized to IBIS in infected red blood cells and two further colocalized with IBIS1 in the liver-stage parasitophorous vacuole membrane. Successful gene deletion revealed that these two tryptophan-rich domain-containing proteins, termed here IPIS2 and IPIS3 (for intraerythrocytic Plasmodium-induced membrane structures), are required for efficient blood-stage growth. Erythrocytes infected with IPIS2-deficient schizonts in particular fail to bind CD36 as efficiently as wild-type P. berghei-infected cells and therefore fail to effectively sequester out of the circulating blood. Our findings support the idea that intra-erythrocytic membrane compartments are required across species for alterations of the host erythrocyte that facilitate interactions of infected cells with host tissues.
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14
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Edgar RCS, Siddiqui G, Hjerrild K, Malcolm TR, Vinh NB, Webb CT, Holmes C, MacRaild CA, Chernih HC, Suen WW, Counihan NA, Creek DJ, Scammells PJ, McGowan S, de Koning-Ward TF. Genetic and chemical validation of Plasmodium falciparum aminopeptidase PfA-M17 as a drug target in the hemoglobin digestion pathway. eLife 2022; 11:e80813. [PMID: 36097817 PMCID: PMC9470162 DOI: 10.7554/elife.80813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/02/2022] [Indexed: 11/18/2022] Open
Abstract
Plasmodium falciparum, the causative agent of malaria, remains a global health threat as parasites continue to develop resistance to antimalarial drugs used throughout the world. Accordingly, drugs with novel modes of action are desperately required to combat malaria. P. falciparum parasites infect human red blood cells where they digest the host's main protein constituent, hemoglobin. Leucine aminopeptidase PfA-M17 is one of several aminopeptidases that have been implicated in the last step of this digestive pathway. Here, we use both reverse genetics and a compound specifically designed to inhibit the activity of PfA-M17 to show that PfA-M17 is essential for P. falciparum survival as it provides parasites with free amino acids for growth, many of which are highly likely to originate from hemoglobin. We further show that loss of PfA-M17 results in parasites exhibiting multiple digestive vacuoles at the trophozoite stage. In contrast to other hemoglobin-degrading proteases that have overlapping redundant functions, we validate PfA-M17 as a potential novel drug target.
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Affiliation(s)
- Rebecca CS Edgar
- School of Medicine, Deakin UniversityGeelongAustralia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin UniversityGeelongAustralia
| | - Ghizal Siddiqui
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | | | - Tess R Malcolm
- Biomedicine Discovery Institute and Department of Microbiology, Monash UniversityClaytonAustralia
- Centre to Impact AMR, Monash UniversityMelbourneAustralia
| | - Natalie B Vinh
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | - Chaille T Webb
- Biomedicine Discovery Institute and Department of Microbiology, Monash UniversityClaytonAustralia
- Centre to Impact AMR, Monash UniversityMelbourneAustralia
| | - Clare Holmes
- CSIRO Australian Centre for Disease PreparednessGeelongAustralia
| | - Christopher A MacRaild
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | - Hope C Chernih
- School of Medicine, Deakin UniversityGeelongAustralia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin UniversityGeelongAustralia
| | - Willy W Suen
- CSIRO Australian Centre for Disease PreparednessGeelongAustralia
| | - Natalie A Counihan
- School of Medicine, Deakin UniversityGeelongAustralia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin UniversityGeelongAustralia
| | - Darren J Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | - Sheena McGowan
- Biomedicine Discovery Institute and Department of Microbiology, Monash UniversityClaytonAustralia
- Centre to Impact AMR, Monash UniversityMelbourneAustralia
| | - Tania F de Koning-Ward
- School of Medicine, Deakin UniversityGeelongAustralia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin UniversityGeelongAustralia
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15
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Looker O, Dans MG, Bullen HE, Sleebs BE, Crabb BS, Gilson PR. The Medicines for Malaria Venture Malaria Box contains inhibitors of protein secretion in
Plasmodium falciparum
blood stage parasites. Traffic 2022; 23:442-461. [PMID: 36040075 PMCID: PMC9543830 DOI: 10.1111/tra.12862] [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: 05/04/2022] [Revised: 07/17/2022] [Accepted: 07/26/2022] [Indexed: 11/27/2022]
Abstract
Plasmodium falciparum parasites which cause malaria, traffic hundreds of proteins into the red blood cells (RBCs) they infect. These exported proteins remodel their RBCs enabling host immune evasion through processes such as cytoadherence that greatly assist parasite survival. As resistance to all current antimalarial compounds is rising new compounds need to be identified and those that could inhibit parasite protein secretion and export would both rapidly reduce parasite virulence and ultimately lead to parasite death. To identify compounds that inhibit protein export we used transgenic parasites expressing an exported nanoluciferase reporter to screen the Medicines for Malaria Venture Malaria Box of 400 antimalarial compounds with mostly unknown targets. The most potent inhibitor identified in this screen was MMV396797 whose application led to export inhibition of both the reporter and endogenous exported proteins. MMV396797 mediated blockage of protein export and slowed the rigidification and cytoadherence of infected RBCs—modifications which are both mediated by parasite‐derived exported proteins. Overall, we have identified a new protein export inhibitor in P. falciparum whose target though unknown, could be developed into a future antimalarial that rapidly inhibits parasite virulence before eliminating parasites from the host.
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Affiliation(s)
| | - Madeline G. Dans
- Burnet Institute Melbourne Australia
- School of Medicine Deakin University Geelong Australia
| | - Hayley E. Bullen
- Burnet Institute Melbourne Australia
- Department of Immunology and Microbiology University of Melbourne Melbourne Australia
| | - Brad E. Sleebs
- The Walter and Eliza Hall Institute of Medical Research Parkville Victoria Australia
- Department of Medical Biology The University of Melbourne Parkville Victoria Australia
| | - Brendan S. Crabb
- Burnet Institute Melbourne Australia
- Department of Immunology and Microbiology University of Melbourne Melbourne Australia
- Department of Immunology and Pathology Monash University Melbourne Australia
| | - Paul R. Gilson
- Burnet Institute Melbourne Australia
- Department of Immunology and Microbiology University of Melbourne Melbourne Australia
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16
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Bullen HE, Sanders PR, Dans MG, Jonsdottir TK, Riglar DT, Looker O, Palmer CS, Kouskousis B, Charnaud SC, Triglia T, Gabriela M, Schneider MP, Chan J, de Koning‐Ward TF, Baum J, Kazura JW, Beeson JG, Cowman AF, Gilson PR, Crabb BS. The
Plasmodium falciparum
parasitophorous vacuole protein
P113
interacts with the parasite protein export machinery and maintains normal vacuole architecture. Mol Microbiol 2022; 117:1245-1262. [PMID: 35403274 PMCID: PMC9544671 DOI: 10.1111/mmi.14904] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/31/2022] [Accepted: 04/05/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Hayley E. Bullen
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Microbiology and Immunology University of Melbourne Parkville Australia
| | | | - Madeline G. Dans
- Burnet Institute 85 Commercial Road Prahran Australia
- School of Medicine Deakin University Waurn Ponds Victoria Australia
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
| | - Thorey K. Jonsdottir
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Microbiology and Immunology University of Melbourne Parkville Australia
| | - David T. Riglar
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
- Department of Medical Biology University of Melbourne Parkville Australia
- Imperial College London Department of Infectious Diseases, South Kensington Campus, SW72AZ UK
| | - Oliver Looker
- Burnet Institute 85 Commercial Road Prahran Australia
| | - Catherine S. Palmer
- Burnet Institute 85 Commercial Road Prahran Australia
- Bio21, 30 Road Parkville Flemington Australia
| | | | - Sarah C. Charnaud
- Burnet Institute 85 Commercial Road Prahran Australia
- WHO Geneva Switzerland
| | - Tony Triglia
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
- Department of Medical Biology University of Melbourne Parkville Australia
| | - Mikha Gabriela
- Burnet Institute 85 Commercial Road Prahran Australia
- School of Medicine Deakin University Waurn Ponds Victoria Australia
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
| | | | - Jo‐Anne Chan
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Medicine University of Melbourne Parkville Victoria Australia
| | | | - Jake Baum
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
- Department of Medical Biology University of Melbourne Parkville Australia
- Imperial College London Department of Infectious Diseases, South Kensington Campus, SW72AZ UK
| | - James W. Kazura
- Centre for Global Health and Diseases Case Western Reserve University Cleveland Ohio USA
| | - James G. Beeson
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Medicine University of Melbourne Parkville Victoria Australia
- Department of Immunology, Central clinical school Monash University Melbourne Victoria Australia
| | - Alan F. Cowman
- Walter and Eliza Hall Institute 1G Royal Parade Parkville Australia
- Department of Medical Biology University of Melbourne Parkville Australia
| | - Paul R. Gilson
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Microbiology and Immunology University of Melbourne Parkville Australia
| | - Brendan S. Crabb
- Burnet Institute 85 Commercial Road Prahran Australia
- Department of Microbiology and Immunology University of Melbourne Parkville Australia
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17
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Gabriela M, Matthews KM, Boshoven C, Kouskousis B, Jonsdottir TK, Bullen HE, Modak J, Steer DL, Sleebs BE, Crabb BS, de Koning-Ward TF, Gilson PR. A revised mechanism for how Plasmodium falciparum recruits and exports proteins into its erythrocytic host cell. PLoS Pathog 2022; 18:e1009977. [PMID: 35192672 PMCID: PMC8896661 DOI: 10.1371/journal.ppat.1009977] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 03/04/2022] [Accepted: 02/10/2022] [Indexed: 11/18/2022] Open
Abstract
Plasmodium falciparum exports ~10% of its proteome into its host erythrocyte to modify the host cell's physiology. The Plasmodium export element (PEXEL) motif contained within the N-terminus of most exported proteins directs the trafficking of those proteins into the erythrocyte. To reach the host cell, the PEXEL motif of exported proteins is processed by the endoplasmic reticulum (ER) resident aspartyl protease plasmepsin V. Then, following secretion into the parasite-encasing parasitophorous vacuole, the mature exported protein must be unfolded and translocated across the parasitophorous vacuole membrane by the Plasmodium translocon of exported proteins (PTEX). PTEX is a protein-conducting channel consisting of the pore-forming protein EXP2, the protein unfoldase HSP101, and structural component PTEX150. The mechanism of how exported proteins are specifically trafficked from the parasite's ER following PEXEL cleavage to PTEX complexes on the parasitophorous vacuole membrane is currently not understood. Here, we present evidence that EXP2 and PTEX150 form a stable subcomplex that facilitates HSP101 docking. We also demonstrate that HSP101 localises both within the parasitophorous vacuole and within the parasite's ER throughout the ring and trophozoite stage of the parasite, coinciding with the timeframe of protein export. Interestingly, we found that HSP101 can form specific interactions with model PEXEL proteins in the parasite's ER, irrespective of their PEXEL processing status. Collectively, our data suggest that HSP101 recognises and chaperones PEXEL proteins from the ER to the parasitophorous vacuole and given HSP101's specificity for the EXP2-PTEX150 subcomplex, this provides a mechanism for how exported proteins are specifically targeted to PTEX for translocation into the erythrocyte.
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Affiliation(s)
- Mikha Gabriela
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- School of Medicine, Deakin University, Geelong, Australia
| | - Kathryn M. Matthews
- School of Medicine, Deakin University, Geelong, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, Australia
| | - Cas Boshoven
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Betty Kouskousis
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Thorey K. Jonsdottir
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Hayley E. Bullen
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Joyanta Modak
- School of Medicine, Deakin University, Geelong, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, Australia
| | - David L. Steer
- Monash Biomedical Proteomics and Metabolomics Facility, Monash University, Melbourne, Australia
| | - Brad E. Sleebs
- ACRF Chemical Biology Division, Walter and Eliza Hall Institute, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Brendan S. Crabb
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
- Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Tania F. de Koning-Ward
- School of Medicine, Deakin University, Geelong, Australia
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, Australia
| | - Paul R. Gilson
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
- * E-mail:
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18
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Kreutzfeld O, Grützke J, Ingmundson A, Müller K, Matuschewski K. Absence of PEXEL-Dependent Protein Export in Plasmodium Liver Stages Cannot Be Restored by Gain of the HSP101 Protein Translocon ATPase. Front Genet 2021; 12:742153. [PMID: 34956312 PMCID: PMC8693896 DOI: 10.3389/fgene.2021.742153] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/18/2021] [Indexed: 11/13/2022] Open
Abstract
Host cell remodeling is critical for successful Plasmodium replication inside erythrocytes and achieved by targeted export of parasite-encoded proteins. In contrast, during liver infection the malarial parasite appears to avoid protein export, perhaps to limit exposure of parasite antigens by infected liver cells. HSP101, the force-generating ATPase of the protein translocon of exported proteins (PTEX) is the only component that is switched off during early liver infection. Here, we generated transgenic Plasmodium berghei parasite lines that restore liver stage expression of HSP101. HSP101 expression in infected hepatocytes was achieved by swapping the endogenous promoter with the ptex150 promoter and by inserting an additional copy under the control of the elongation one alpha (ef1α) promoter. Both promoters drive constitutive and, hence, also pre-erythrocytic expression. Transgenic parasites were able to complete the life cycle, but failed to export PEXEL-proteins in early liver stages. Our results suggest that PTEX-dependent early liver stage export cannot be restored by addition of HSP101, indicative of alternative export complexes or other functions of the PTEX core complex during liver infection.
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Affiliation(s)
- Oriana Kreutzfeld
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.,Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Josephine Grützke
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.,Department of Biological Safety, Federal Institute for Risk Assessment, Berlin, Germany
| | - Alyssa Ingmundson
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Katja Müller
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Kai Matuschewski
- Molecular Parasitology, Institute of Biology/Faculty for Life Sciences, Humboldt Universität zu Berlin, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
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19
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Protein Sorting in Plasmodium Falciparum. Life (Basel) 2021; 11:life11090937. [PMID: 34575086 PMCID: PMC8467625 DOI: 10.3390/life11090937] [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: 06/30/2021] [Revised: 09/04/2021] [Accepted: 09/04/2021] [Indexed: 11/23/2022] Open
Abstract
Plasmodium falciparum is a unicellular eukaryote with a very polarized secretory system composed of micronemes rhoptries and dense granules that are required for host cell invasion. P. falciparum, like its relative T. gondii, uses the endolysosomal system to produce the secretory organelles and to ingest host cell proteins. The parasite also has an apicoplast, a secondary endosymbiotic organelle, which depends on vesicular trafficking for appropriate incorporation of nuclear-encoded proteins into the apicoplast. Recently, the central molecules responsible for sorting and trafficking in P. falciparum and T. gondii have been characterized. From these studies, it is now evident that P. falciparum has repurposed the molecules of the endosomal system to the secretory pathway. Additionally, the sorting and vesicular trafficking mechanism seem to be conserved among apicomplexans. This review described the most recent findings on the molecular mechanisms of protein sorting and vesicular trafficking in P. falciparum and revealed that P. falciparum has an amazing secretory machinery that has been cleverly modified to its intracellular lifestyle.
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20
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Wiser MF. Unique Endomembrane Systems and Virulence in Pathogenic Protozoa. Life (Basel) 2021; 11:life11080822. [PMID: 34440567 PMCID: PMC8401336 DOI: 10.3390/life11080822] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/10/2021] [Accepted: 08/10/2021] [Indexed: 02/06/2023] Open
Abstract
Virulence in pathogenic protozoa is often tied to secretory processes such as the expression of adhesins on parasite surfaces or the secretion of proteases to assisted in tissue invasion and other proteins to avoid the immune system. This review is a broad overview of the endomembrane systems of pathogenic protozoa with a focus on Giardia, Trichomonas, Entamoeba, kinetoplastids, and apicomplexans. The focus is on unique features of these protozoa and how these features relate to virulence. In general, the basic elements of the endocytic and exocytic pathways are present in all protozoa. Some of these elements, especially the endosomal compartments, have been repurposed by the various species and quite often the repurposing is associated with virulence. The Apicomplexa exhibit the most unique endomembrane systems. This includes unique secretory organelles that play a central role in interactions between parasite and host and are involved in the invasion of host cells. Furthermore, as intracellular parasites, the apicomplexans extensively modify their host cells through the secretion of proteins and other material into the host cell. This includes a unique targeting motif for proteins destined for the host cell. Most notable among the apicomplexans is the malaria parasite, which extensively modifies and exports numerous proteins into the host erythrocyte. These modifications of the host erythrocyte include the formation of unique membranes and structures in the host erythrocyte cytoplasm and on the erythrocyte membrane. The transport of parasite proteins to the host erythrocyte involves several unique mechanisms and components, as well as the generation of compartments within the erythrocyte that participate in extraparasite trafficking.
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Affiliation(s)
- Mark F Wiser
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA 70112, USA
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21
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Wichers JS, Wunderlich J, Heincke D, Pazicky S, Strauss J, Schmitt M, Kimmel J, Wilcke L, Scharf S, von Thien H, Burda PC, Spielmann T, Löw C, Filarsky M, Bachmann A, Gilberger TW. Identification of novel inner membrane complex and apical annuli proteins of the malaria parasite Plasmodium falciparum. Cell Microbiol 2021; 23:e13341. [PMID: 33830607 DOI: 10.1111/cmi.13341] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/29/2021] [Accepted: 04/05/2021] [Indexed: 02/06/2023]
Abstract
The inner membrane complex (IMC) is a defining feature of apicomplexan parasites, which confers stability and shape to the cell, functions as a scaffolding compartment during the formation of daughter cells and plays an important role in motility and invasion during different life cycle stages of these single-celled organisms. To explore the IMC proteome of the malaria parasite Plasmodium falciparum we applied a proximity-dependent biotin identification (BioID)-based proteomics approach, using the established IMC marker protein Photosensitized INA-Labelled protein 1 (PhIL1) as bait in asexual blood-stage parasites. Subsequent mass spectrometry-based peptide identification revealed enrichment of 12 known IMC proteins and several uncharacterized candidate proteins. We validated nine of these previously uncharacterized proteins by endogenous GFP-tagging. Six of these represent new IMC proteins, while three proteins have a distinct apical localization that most likely represents structures described as apical annuli in Toxoplasma gondii. Additionally, various Kelch13 interacting candidates were identified, suggesting an association of the Kelch13 compartment and the IMC in schizont and merozoite stages. This work extends the number of validated IMC proteins in the malaria parasite and reveals for the first time the existence of apical annuli proteins in P. falciparum. Additionally, it provides evidence for a spatial association between the Kelch13 compartment and the IMC in late blood-stage parasites.
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Affiliation(s)
- Jan Stephan Wichers
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Juliane Wunderlich
- Centre for Structural Systems Biology, Hamburg, Germany.,European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Dorothee Heincke
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Samuel Pazicky
- Centre for Structural Systems Biology, Hamburg, Germany.,European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Jan Strauss
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Marius Schmitt
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jessica Kimmel
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Louisa Wilcke
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Sarah Scharf
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Heidrun von Thien
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Paul-Christian Burda
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Tobias Spielmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Christian Löw
- Centre for Structural Systems Biology, Hamburg, Germany.,European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Michael Filarsky
- Centre for Structural Systems Biology, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Anna Bachmann
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany.,German Centre for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Braunschweig, Germany
| | - Tim W Gilberger
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
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22
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Jonsdottir TK, Gabriela M, Crabb BS, F de Koning-Ward T, Gilson PR. Defining the Essential Exportome of the Malaria Parasite. Trends Parasitol 2021; 37:664-675. [PMID: 33985912 DOI: 10.1016/j.pt.2021.04.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/15/2021] [Accepted: 04/15/2021] [Indexed: 02/06/2023]
Abstract
To survive inside red blood cells (RBCs), malaria parasites export many proteins to alter their host cell's physiological properties. Although most proteins of this exportome are involved in immune avoidance or in the trafficking of exported proteins to the host membrane, about 20% are essential for parasite survival in culture but little is known about their biological functions. Here, we have combined information from large-scale genetic screens and targeted gene-disruption studies to tabulate all currently known Plasmodium falciparum exported proteins according to their likelihood of being essential. We also discuss the essential functional pathways that exported proteins might be involved in to help direct research efforts towards a more comprehensive understanding of host-cell remodelling.
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Affiliation(s)
- Thorey K Jonsdottir
- Burnet Institute, Melbourne, Victoria 3004, Australia; Department of Microbiology and Immunology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Mikha Gabriela
- Burnet Institute, Melbourne, Victoria 3004, Australia; School of Medicine, Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Brendan S Crabb
- Burnet Institute, Melbourne, Victoria 3004, Australia; Department of Microbiology and Immunology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | | | - Paul R Gilson
- Burnet Institute, Melbourne, Victoria 3004, Australia.
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23
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Miyazaki S, Chitama BYA, Kagaya W, Lucky AB, Zhu X, Yahata K, Morita M, Takashima E, Tsuboi T, Kaneko O. Plasmodium falciparum SURFIN 4.1 forms an intermediate complex with PTEX components and Pf113 during export to the red blood cell. Parasitol Int 2021; 83:102358. [PMID: 33901679 DOI: 10.1016/j.parint.2021.102358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/08/2021] [Accepted: 04/14/2021] [Indexed: 02/04/2023]
Abstract
Plasmodium falciparum malaria parasites export several hundred proteins to the cytoplasm of infected red blood cells (RBCs) to modify the cell environment suitable for their growth. A Plasmodium translocon of exported proteins (PTEX) is necessary for both soluble and integral membrane proteins to cross the parasitophorous vacuole (PV) membrane surrounding the parasite inside the RBC. However, the molecular composition of the translocation complex for integral membrane proteins is not fully characterized, especially at the parasite plasma membrane. To examine the translocation complex, here we used mini-SURFIN4.1, consisting of a short N-terminal region, a transmembrane region, and a cytoplasmic region of an exported integral membrane protein SURFIN4.1. We found that mini-SURFIN4.1 forms a translocation intermediate complex with core PTEX components, EXP2, HSP101, and PTEX150. We also found that several proteins are exposed to the PV space, including Pf113, an uncharacterized PTEX-associated protein. We determined that Pf113 localizes in dense granules at the merozoite stage and on the parasite periphery after RBC invasion. Using an inducible translocon-clogged mini-SURFIN4.1, we found that a stable translocation intermediate complex forms at the parasite plasma membrane and contains EXP2 and a processed form of Pf113. These results suggest a potential role of Pf113 for the translocation step of mini-SURFIN4.1, providing further insights into the translocation mechanisms for parasite integral membrane proteins.
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Affiliation(s)
- Shinya Miyazaki
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - Ben-Yeddy Abel Chitama
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan; Program for Nurturing Global Leaders in Tropical and Emerging Infectious Diseases, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Wataru Kagaya
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan; Department of Environmental Parasitology, Graduate School of Tokyo Medical and Dental University, Tokyo, Japan
| | - Amuza Byaruhanga Lucky
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan; Program for Nurturing Global Leaders in Tropical and Emerging Infectious Diseases, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Xiaotong Zhu
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - Kazuhide Yahata
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - Masayuki Morita
- Division of Malaria Research, Proteo-Science Center, Ehime University, Ehime, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Ehime, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Ehime, Japan
| | - Osamu Kaneko
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan; Program for Nurturing Global Leaders in Tropical and Emerging Infectious Diseases, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
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24
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Abstract
Obligate intracellular malaria parasites reside within a vacuolar compartment generated during invasion which is the principal interface between pathogen and host. To subvert their host cell and support their metabolism, these parasites coordinate a range of transport activities at this membrane interface that are critically important to parasite survival and virulence, including nutrient import, waste efflux, effector protein export, and uptake of host cell cytosol. Here, we review our current understanding of the transport mechanisms acting at the malaria parasite vacuole during the blood and liver-stages of development with a particular focus on recent advances in our understanding of effector protein translocation into the host cell by the Plasmodium Translocon of EXported proteins (PTEX) and small molecule transport by the PTEX membrane-spanning pore EXP2. Comparison to Toxoplasma gondii and other related apicomplexans is provided to highlight how similar and divergent mechanisms are employed to fulfill analogous transport activities.
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Affiliation(s)
- Josh R. Beck
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Chi-Min Ho
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
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25
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Jonsdottir TK, Gabriela M, Gilson PR. The Role of Malaria Parasite Heat Shock Proteins in Protein Trafficking and Remodelling of Red Blood Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1340:141-167. [PMID: 34569024 DOI: 10.1007/978-3-030-78397-6_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The genus Plasmodium comprises intracellular eukaryotic parasites that infect many vertebrate groups and cause deadly malaria disease in humans. The parasites employ a suite of heat shock proteins to help traffic other proteins to different compartments within their own cells and that of the host cells they parasitise. This review will cover the role of these chaperones in protein export and host cell modification in the asexual blood stage of the human parasite P. falciparum which is the most deadly and well-studied parasite species. We will examine the role chaperones play in the import of proteins into the secretory pathway from where they are escorted to the vacuole space surrounding the intraerythrocytic parasite. Here, other heat shock proteins unfold protein cargoes and extrude them into the red blood cell (RBC) cytosol from where additional chaperones of parasite and possibly host origin refold the cargo proteins and guide them to their final functional destinations within their RBC host cells. The secretory pathway also serves as a launch pad for proteins targeted to the non-photosynthetic apicoplast organelle of endosymbiotic origin, and the role of heat shock proteins in trafficking proteins here will be reviewed. Finally, the function of chaperones in protein trafficking into the mitochondrion, the remaining organelle of endosymbiotic origin, will be discussed.
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Affiliation(s)
- Thorey K Jonsdottir
- Burnet Institute, Melbourne, VIC, Australia.,Department of Microbiology and Immunology, University of Melbourne, Parkville, VIC, Australia
| | - Mikha Gabriela
- Burnet Institute, Melbourne, VIC, Australia.,School of Medicine, Deakin University, Waurn Ponds, VIC, Australia
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26
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March ZM, Sweeney K, Kim H, Yan X, Castellano LM, Jackrel ME, Lin J, Chuang E, Gomes E, Willicott CW, Michalska K, Jedrzejczak RP, Joachimiak A, Caldwell KA, Caldwell GA, Shalem O, Shorter J. Therapeutic genetic variation revealed in diverse Hsp104 homologs. eLife 2020; 9:e57457. [PMID: 33319748 PMCID: PMC7785292 DOI: 10.7554/elife.57457] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
The AAA+ protein disaggregase, Hsp104, increases fitness under stress by reversing stress-induced protein aggregation. Natural Hsp104 variants might exist with enhanced, selective activity against neurodegenerative disease substrates. However, natural Hsp104 variation remains largely unexplored. Here, we screened a cross-kingdom collection of Hsp104 homologs in yeast proteotoxicity models. Prokaryotic ClpG reduced TDP-43, FUS, and α-synuclein toxicity, whereas prokaryotic ClpB and hyperactive variants were ineffective. We uncovered therapeutic genetic variation among eukaryotic Hsp104 homologs that specifically antagonized TDP-43 condensation and toxicity in yeast and TDP-43 aggregation in human cells. We also uncovered distinct eukaryotic Hsp104 homologs that selectively antagonized α-synuclein condensation and toxicity in yeast and dopaminergic neurodegeneration in C. elegans. Surprisingly, this therapeutic variation did not manifest as enhanced disaggregase activity, but rather as increased passive inhibition of aggregation of specific substrates. By exploring natural tuning of this passive Hsp104 activity, we elucidated enhanced, substrate-specific agents that counter proteotoxicity underlying neurodegeneration.
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Affiliation(s)
- Zachary M March
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Department of Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Katelyn Sweeney
- Department of Genetics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of PhiladelphiaPhiladelphiaUnited States
| | - Hanna Kim
- Department of Biological Sciences, The University of AlabamaTuscaloosaUnited States
| | - Xiaohui Yan
- Department of Biological Sciences, The University of AlabamaTuscaloosaUnited States
| | - Laura M Castellano
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Pharmacology Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Meredith E Jackrel
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - JiaBei Lin
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Edward Chuang
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Pharmacology Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Edward Gomes
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Corey W Willicott
- Department of Biological Sciences, The University of AlabamaTuscaloosaUnited States
| | - Karolina Michalska
- Structural Biology Center, X-ray Science Division, Argonne National LaboratoryArgonneUnited States
- Department of Biochemistry and Molecular Biology, University of ChicagoChicagoUnited States
| | - Robert P Jedrzejczak
- Structural Biology Center, X-ray Science Division, Argonne National LaboratoryArgonneUnited States
| | - Andrzej Joachimiak
- Structural Biology Center, X-ray Science Division, Argonne National LaboratoryArgonneUnited States
- Department of Biochemistry and Molecular Biology, University of ChicagoChicagoUnited States
| | - Kim A Caldwell
- Department of Biological Sciences, The University of AlabamaTuscaloosaUnited States
| | - Guy A Caldwell
- Department of Biological Sciences, The University of AlabamaTuscaloosaUnited States
| | - Ophir Shalem
- Department of Genetics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of PhiladelphiaPhiladelphiaUnited States
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Department of Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Pharmacology Graduate Group, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
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27
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Mello-Vieira J, Enguita FJ, de Koning-Ward TF, Zuzarte-Luís V, Mota MM. Plasmodium translocon component EXP2 facilitates hepatocyte invasion. Nat Commun 2020; 11:5654. [PMID: 33159090 PMCID: PMC7648069 DOI: 10.1038/s41467-020-19492-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 10/08/2020] [Indexed: 12/11/2022] Open
Abstract
Plasmodium parasites possess a translocon that exports parasite proteins into the infected erythrocyte. Although the translocon components are also expressed during the mosquito and liver stage of infection, their function remains unexplored. Here, using a combination of genetic and chemical assays, we show that the translocon component Exported Protein 2 (EXP2) is critical for invasion of hepatocytes. EXP2 is a pore-forming protein that is secreted from the sporozoite upon contact with the host cell milieu. EXP2-deficient sporozoites are impaired in invasion, which can be rescued by the exogenous administration of recombinant EXP2 and alpha-hemolysin (an S. aureus pore-forming protein), as well as by acid sphingomyelinase. The latter, together with the negative impact of chemical and genetic inhibition of acid sphingomyelinase on invasion, reveals that EXP2 pore-forming activity induces hepatocyte membrane repair, which plays a key role in parasite invasion. Overall, our findings establish a novel and critical function for EXP2 that leads to an active participation of the host cell in Plasmodium sporozoite invasion, challenging the current view of the establishment of liver stage infection. While the role of Plasmodium EXP2 protein as translocon component of blood stage parasites is established, its functional role in liver stage parasites remains unclear. Here, Mello-Vieira et al. reveal that EXP2 pore-forming activity induces hepatocyte membrane repair and hence is critical for hepatocyte invasion.
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Affiliation(s)
- João Mello-Vieira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal
| | - Francisco J Enguita
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal
| | | | - Vanessa Zuzarte-Luís
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal.
| | - Maria M Mota
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal.
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28
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Matz JM, Drepper B, Blum TB, van Genderen E, Burrell A, Martin P, Stach T, Collinson LM, Abrahams JP, Matuschewski K, Blackman MJ. A lipocalin mediates unidirectional heme biomineralization in malaria parasites. Proc Natl Acad Sci U S A 2020; 117:16546-16556. [PMID: 32601225 PMCID: PMC7368307 DOI: 10.1073/pnas.2001153117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
During blood-stage development, malaria parasites are challenged with the detoxification of enormous amounts of heme released during the proteolytic catabolism of erythrocytic hemoglobin. They tackle this problem by sequestering heme into bioinert crystals known as hemozoin. The mechanisms underlying this biomineralization process remain enigmatic. Here, we demonstrate that both rodent and human malaria parasite species secrete and internalize a lipocalin-like protein, PV5, to control heme crystallization. Transcriptional deregulation of PV5 in the rodent parasite Plasmodium berghei results in inordinate elongation of hemozoin crystals, while conditional PV5 inactivation in the human malaria agent Plasmodium falciparum causes excessive multidirectional crystal branching. Although hemoglobin processing remains unaffected, PV5-deficient parasites generate less hemozoin. Electron diffraction analysis indicates that despite the distinct changes in crystal morphology, neither the crystalline order nor unit cell of hemozoin are affected by impaired PV5 function. Deregulation of PV5 expression renders P. berghei hypersensitive to the antimalarial drugs artesunate, chloroquine, and atovaquone, resulting in accelerated parasite clearance following drug treatment in vivo. Together, our findings demonstrate the Plasmodium-tailored role of a lipocalin family member in hemozoin formation and underscore the heme biomineralization pathway as an attractive target for therapeutic exploitation.
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Affiliation(s)
- Joachim M Matz
- Malaria Biochemistry Laboratory, The Francis Crick Institute, NW1 1AT London, United Kingdom;
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Benjamin Drepper
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Thorsten B Blum
- Laboratory of Nanoscale Biology, Division of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Eric van Genderen
- Laboratory of Nanoscale Biology, Division of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Alana Burrell
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Peer Martin
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Thomas Stach
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Lucy M Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Jan Pieter Abrahams
- Laboratory of Nanoscale Biology, Division of Biology and Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, 4051 Basel, Switzerland
- Institute of Biology, Leiden University, 2311 EZ Leiden, The Netherlands
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115 Berlin, Germany
| | - Michael J Blackman
- Malaria Biochemistry Laboratory, The Francis Crick Institute, NW1 1AT London, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, WC1E 7HT London, United Kingdom
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29
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Crossing the Vacuolar Rubicon: Structural Insights into Effector Protein Trafficking in Apicomplexan Parasites. Microorganisms 2020; 8:microorganisms8060865. [PMID: 32521667 PMCID: PMC7355975 DOI: 10.3390/microorganisms8060865] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 12/13/2022] Open
Abstract
Apicomplexans form a large phylum of parasitic protozoa, including the genera Plasmodium, Toxoplasma, and Cryptosporidium, the causative agents of malaria, toxoplasmosis, and cryptosporidiosis, respectively. They cause diseases not only in humans but also in animals, with dramatic consequences in agriculture. Most apicomplexans are vacuole-dwelling and obligate intracellular parasites; as they invade the host cell, they become encased in a parasitophorous vacuole (PV) derived from the host cellular membrane. This creates a parasite-host interface that acts as a protective barrier but also constitutes an obstacle through which the pathogen must import nutrients, eliminate wastes, and eventually break free upon egress. Completion of the parasitic life cycle requires intense remodeling of the infected host cell. Host cell subversion is mediated by a subset of essential effector parasitic proteins and virulence factors actively trafficked across the PV membrane. In the malaria parasite Plasmodium, a unique and highly specialized ATP-driven vacuolar secretion system, the Plasmodium translocon of exported proteins (PTEX), transports effector proteins across the vacuolar membrane. Its core is composed of the three essential proteins EXP2, PTEX150, and HSP101, and is supplemented by the two auxiliary proteins TRX2 and PTEX88. Many but not all secreted malarial effector proteins contain a vacuolar trafficking signal or Plasmodium export element (PEXEL) that requires processing by an endoplasmic reticulum protease, plasmepsin V, for proper export. Because vacuolar parasitic protein export is essential to parasite survival and virulence, this pathway is a promising target for the development of novel antimalarial therapeutics. This review summarizes the current state of structural and mechanistic knowledge on the Plasmodium parasitic vacuolar secretion and effector trafficking pathway, describing its most salient features and discussing the existing differences and commonalities with the vacuolar effector translocation MYR machinery recently described in Toxoplasma and other apicomplexans of significance to medical and veterinary sciences.
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30
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Florentin A, Cobb DW, Kudyba HM, Muralidharan V. Directing traffic: Chaperone-mediated protein transport in malaria parasites. Cell Microbiol 2020; 22:e13215. [PMID: 32388921 PMCID: PMC7282954 DOI: 10.1111/cmi.13215] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/12/2020] [Accepted: 04/14/2020] [Indexed: 12/16/2022]
Abstract
The ability of eukaryotic parasites from the phylum Apicomplexa to cause devastating diseases is predicated upon their ability to maintain faithful and precise protein trafficking mechanisms. Their parasitic life cycle depends on the trafficking of effector proteins to the infected host cell, transport of proteins to several critical organelles required for survival, as well as transport of parasite and host proteins to the digestive organelles to generate the building blocks for parasite growth. Several recent studies have shed light on the molecular mechanisms parasites utilise to transform the infected host cells, transport proteins to essential metabolic organelles and for biogenesis of organelles required for continuation of their life cycle. Here, we review key pathways of protein transport originating and branching from the endoplasmic reticulum, focusing on the essential roles of chaperones in these processes. Further, we highlight key gaps in our knowledge that prevents us from building a holistic view of protein trafficking in these deadly human pathogens.
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Affiliation(s)
- Anat Florentin
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - David W Cobb
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Heather M Kudyba
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Vasant Muralidharan
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
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31
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Tougan T, Edula JR, Morita M, Takashima E, Honma H, Tsuboi T, Horii T. The malaria parasite Plasmodium falciparum in red blood cells selectively takes up serum proteins that affect host pathogenicity. Malar J 2020; 19:155. [PMID: 32295584 PMCID: PMC7161009 DOI: 10.1186/s12936-020-03229-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/07/2020] [Indexed: 11/12/2022] Open
Abstract
Background The malaria parasite Plasmodium falciparum is a protozoan that develops in red blood cells (RBCs) and requires various host factors. For its development in RBCs, nutrients not only from the RBC cytosol but also from the extracellular milieu must be acquired. Although the utilization of host nutrients by P. falciparum has been extensively analysed, only a few studies have reported its utilization of host serum proteins. Hence, the aim of the current study was to comprehensively identify host serum proteins taken up by P. falciparum parasites and to elucidate their role in pathogenesis. Methods Plasmodium falciparum was cultured with human serum in vitro. Uptake of serum proteins by parasites was comprehensively determined via shotgun liquid chromatography–mass spectrometry/mass spectrometry and western blotting. The calcium ion concentration in serum was also evaluated, and coagulation activity of the parasite lysate was assessed. Results Three proteins, vitamin K-dependent protein S, prothrombin, and vitronectin, were selectively internalized under sufficient Ca2+ levels in the culture medium. The uptake of these proteins was initiated before DNA replication, and increased during the trophozoite and schizont stages, irrespective of the assembly/disassembly of actin filaments. Coagulation assay revealed that prothrombin was activated and thereby induced blood coagulation. Conclusions Serum proteins were taken up by parasites under culture conditions with sufficient Ca2+ levels. This uptake phenomenon was associated with their pathogenicity.
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Affiliation(s)
- Takahiro Tougan
- Research Centre for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Jyotheeswara R Edula
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Cell and Developmental Biology Section, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Masayuki Morita
- Division of Malaria Research, Proteo-Science Centre, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime, 790-8577, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Centre, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime, 790-8577, Japan
| | - Hajime Honma
- Department of International Affairs and Tropical Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Centre, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime, 790-8577, Japan
| | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
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32
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PfCERLI1 is a conserved rhoptry associated protein essential for Plasmodium falciparum merozoite invasion of erythrocytes. Nat Commun 2020; 11:1411. [PMID: 32179747 PMCID: PMC7075938 DOI: 10.1038/s41467-020-15127-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 02/15/2020] [Indexed: 12/01/2022] Open
Abstract
The disease-causing blood-stage of the Plasmodium falciparum lifecycle begins with invasion of human erythrocytes by merozoites. Many vaccine candidates with key roles in binding to the erythrocyte surface and entry are secreted from the large bulb-like rhoptry organelles at the apical tip of the merozoite. Here we identify an essential role for the conserved protein P. falciparum Cytosolically Exposed Rhoptry Leaflet Interacting protein 1 (PfCERLI1) in rhoptry function. We show that PfCERLI1 localises to the cytosolic face of the rhoptry bulb membrane and knockdown of PfCERLI1 inhibits merozoite invasion. While schizogony and merozoite organelle biogenesis appear normal, biochemical techniques and semi-quantitative super-resolution microscopy show that PfCERLI1 knockdown prevents secretion of key rhoptry antigens that coordinate merozoite invasion. PfCERLI1 is a rhoptry associated protein identified to have a direct role in function of this essential merozoite invasion organelle, which has broader implications for understanding apicomplexan invasion biology. Rhoptries are essential organelles for invasion of erythrocytes by Plasmodium. Here, the authors characterize the rhoptry-associated protein CERLI1 using quantitative super-resolution microscopy, showing that it is important for parasite invasion and secretion of rhoptry proteins including vaccine antigens.
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33
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Nessel T, Beck JM, Rayatpisheh S, Jami-Alahmadi Y, Wohlschlegel JA, Goldberg DE, Beck JR. EXP1 is required for organisation of EXP2 in the intraerythrocytic malaria parasite vacuole. Cell Microbiol 2020; 22:e13168. [PMID: 31990132 DOI: 10.1111/cmi.13168] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 12/04/2019] [Accepted: 01/07/2020] [Indexed: 12/17/2022]
Abstract
Intraerythrocytic malaria parasites reside within a parasitophorous vacuole membrane (PVM) that closely overlays the parasite plasma membrane. Although the PVM is the site of several transport activities essential to parasite survival, the basis for organisation of this membrane system is unknown. Here, we performed proximity labeling at the PVM with BioID2, which highlighted a group of single-pass integral membrane proteins that constitute a major component of the PVM proteome but whose function remains unclear. We investigated EXP1, the longest known member of this group, by adapting a CRISPR/Cpf1 genome editing system to install the TetR-DOZI-aptamers system for conditional translational control. Importantly, although EXP1 was required for intraerythrocytic development, a previously reported in vitro glutathione S-transferase activity could not account for this essential EXP1 function in vivo. EXP1 knockdown was accompanied by profound changes in vacuole ultrastructure, including apparent increased separation of the PVM from the parasite plasma membrane and formation of abnormal membrane structures. Furthermore, although activity of the Plasmodium translocon of exported proteins was not impacted by depletion of EXP1, the distribution of the translocon pore-forming protein EXP2 but not the HSP101 unfoldase was substantially altered. Collectively, our results reveal a novel PVM defect that indicates a critical role for EXP1 in maintaining proper organisation of EXP2 within the PVM.
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Affiliation(s)
- Timothy Nessel
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa
| | - John M Beck
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa
| | - Shima Rayatpisheh
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, California
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, California
| | - James A Wohlschlegel
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, California
| | - Daniel E Goldberg
- Departments of Medicine and Molecular Microbiology, Washington University, St. Louis, Missouri
| | - Josh R Beck
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa.,Departments of Medicine and Molecular Microbiology, Washington University, St. Louis, Missouri
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34
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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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35
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The parasitophorous vacuole of the blood-stage malaria parasite. Nat Rev Microbiol 2020; 18:379-391. [PMID: 31980807 DOI: 10.1038/s41579-019-0321-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2019] [Indexed: 12/31/2022]
Abstract
The pathology of malaria is caused by infection of red blood cells with unicellular Plasmodium parasites. During blood-stage development, the parasite replicates within a membrane-bound parasitophorous vacuole. A central nexus for host-parasite interactions, this unique parasite shelter functions in nutrient acquisition, subcompartmentalization and the export of virulence factors, making its functional molecules attractive targets for the development of novel intervention strategies to combat the devastating impact of malaria. In this Review, we explore the origin, development, molecular composition and functions of the parasitophorous vacuole of Plasmodium blood stages. We also discuss the relevance of the malaria parasite's intravacuolar lifestyle for successful erythrocyte infection and provide perspectives for future research directions in parasitophorous vacuole biology.
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36
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Zininga T, Shonhai A. Small Molecule Inhibitors Targeting the Heat Shock Protein System of Human Obligate Protozoan Parasites. Int J Mol Sci 2019; 20:E5930. [PMID: 31775392 PMCID: PMC6929125 DOI: 10.3390/ijms20235930] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/29/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022] Open
Abstract
Obligate protozoan parasites of the kinetoplastids and apicomplexa infect human cells to complete their life cycles. Some of the members of these groups of parasites develop in at least two systems, the human host and the insect vector. Survival under the varied physiological conditions associated with the human host and in the arthropod vectors requires the parasites to modulate their metabolic complement in order to meet the prevailing conditions. One of the key features of these parasites essential for their survival and host infectivity is timely expression of various proteins. Even more importantly is the need to keep their proteome functional by maintaining its functional capabilities in the wake of physiological changes and host immune responses. For this reason, molecular chaperones (also called heat shock proteins)-whose role is to facilitate proteostasis-play an important role in the survival of these parasites. Heat shock protein 90 (Hsp90) and Hsp70 are prominent molecular chaperones that are generally induced in response to physiological stress. Both Hsp90 and Hsp70 members are functionally regulated by nucleotides. In addition, Hsp70 and Hsp90 cooperate to facilitate folding of some key proteins implicated in cellular development. In addition, Hsp90 and Hsp70 individually interact with other accessory proteins (co-chaperones) that regulate their functions. The dependency of these proteins on nucleotide for their chaperone function presents an Achille's heel, as inhibitors that mimic ATP are amongst potential therapeutic agents targeting their function in obligate intracellular human parasites. Most of the promising small molecule inhibitors of parasitic heat shock proteins are either antibiotics or anticancer agents, whose repurposing against parasitic infections holds prospects. Both cancer cells and obligate human parasites depend upon a robust protein quality control system to ensure their survival, and hence, both employ a competent heat shock machinery to this end. Furthermore, some inhibitors that target chaperone and co-chaperone networks also offer promising prospects as antiparasitic agents. The current review highlights the progress made so far in design and application of small molecule inhibitors against obligate intracellular human parasites of the kinetoplastida and apicomplexan kingdoms.
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Affiliation(s)
| | - Addmore Shonhai
- Department of Biochemistry, School of Mathematical and Natural Sciences, University of Venda, Thohoyandou 0950, South Africa;
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37
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Mesén-Ramírez P, Bergmann B, Tran TT, Garten M, Stäcker J, Naranjo-Prado I, Höhn K, Zimmerberg J, Spielmann T. EXP1 is critical for nutrient uptake across the parasitophorous vacuole membrane of malaria parasites. PLoS Biol 2019; 17:e3000473. [PMID: 31568532 PMCID: PMC6786648 DOI: 10.1371/journal.pbio.3000473] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 10/10/2019] [Accepted: 09/10/2019] [Indexed: 12/02/2022] Open
Abstract
Intracellular malaria parasites grow in a vacuole delimited by the parasitophorous vacuolar membrane (PVM). This membrane fulfils critical roles for survival of the parasite in its intracellular niche such as in protein export and nutrient acquisition. Using a conditional knockout (KO), we here demonstrate that the abundant integral PVM protein exported protein 1 (EXP1) is essential for parasite survival but that this is independent of its previously postulated function as a glutathione S-transferase (GST). Patch-clamp experiments indicated that EXP1 is critical for the nutrient-permeable channel activity at the PVM. Loss of EXP1 abolished the correct localisation of EXP2, a pore-forming protein required for the nutrient-permeable channel activity and protein export at the PVM. Unexpectedly, loss of EXP1 affected only the nutrient-permeable channel activity of the PVM but not protein export. Parasites with low levels of EXP1 became hypersensitive to low nutrient conditions, indicating that EXP1 indeed is needed for nutrient uptake and experimentally confirming the long-standing hypothesis that the channel activity measured at the PVM is required for parasite nutrient acquisition. Hence, EXP1 is specifically required for the functional expression of EXP2 as the nutrient-permeable channel and is critical for the metabolite supply of malaria parasites. Intracellular malaria parasites reside in a vacuole that is formed by the parasitophorous vacuolar membrane (PVM) that separates the parasite from the host cell. Conditional knock-out reveals that the major integral PVM protein EXP1 is essential for the nutrient permeable channel activity of the PVM, and implicates this channel in parasite nutrient acquisition.
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Affiliation(s)
- Paolo Mesén-Ramírez
- Molecular Biology and Immunology Section, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Bärbel Bergmann
- Molecular Biology and Immunology Section, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Thuy Tuyen Tran
- Molecular Biology and Immunology Section, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Matthias Garten
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jan Stäcker
- Molecular Biology and Immunology Section, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Isabel Naranjo-Prado
- Molecular Biology and Immunology Section, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Katharina Höhn
- Electron Microscopy Unit, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Joshua Zimmerberg
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Tobias Spielmann
- Molecular Biology and Immunology Section, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- * E-mail:
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38
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Translocation of effector proteins into host cells by Toxoplasma gondii. Curr Opin Microbiol 2019; 52:130-138. [PMID: 31446366 DOI: 10.1016/j.mib.2019.07.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/19/2019] [Accepted: 07/22/2019] [Indexed: 12/12/2022]
Abstract
The Apicomplexan parasite, Toxoplasma gondii, is an obligate intracellular organism that must co-opt its host cell to survive. To this end, Toxoplasma parasites introduce a suite of effector proteins from two secretory compartments called rhoptries and dense granules into the host cells. Once inside, these effectors extensively modify the host cell to facilitate parasite penetration, replication and persistence. In this review, we summarize the most recent advances in current understanding of effector translocation from Toxoplasma's rhoptry and dense granule organelles into the host cell, with comparisons to Plasmodium spp. for broader context.
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39
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Shears MJ, Sekhar Nirujogi R, Swearingen KE, Renuse S, Mishra S, Jaipal Reddy P, Moritz RL, Pandey A, Sinnis P. Proteomic Analysis of Plasmodium Merosomes: The Link between Liver and Blood Stages in Malaria. J Proteome Res 2019; 18:3404-3418. [PMID: 31335145 DOI: 10.1021/acs.jproteome.9b00324] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The pre-erythrocytic liver stage of the malaria parasite, comprising sporozoites and the liver stages into which they develop, remains one of the least understood parts of the lifecycle, in part owing to the low numbers of parasites. Nonetheless, it is recognized as an important target for antimalarial drugs and vaccines. Here we provide the first proteomic analysis of merosomes, which define the final phase of the liver stage and are responsible for initiating the blood stage of infection. We identify a total of 1879 parasite proteins, and a core set of 1188 proteins quantitatively detected in every biological replicate, providing an extensive picture of the protein repertoire of this stage. This unique data set will allow us to explore key questions about the biology of merosomes and hepatic merozoites.
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Affiliation(s)
- Melanie J Shears
- Department of Molecular Microbiology & Immunology , Johns Hopkins Bloomberg School of Public Health , 615 North Wolfe Street , Baltimore , Maryland 21205 , United States
| | - Raja Sekhar Nirujogi
- Department of Biological Chemistry , Johns Hopkins School of Medicine , 733 N. Broadway , Baltimore , Maryland 21205 , United States.,Institute of Bioinformatics , International Tech Park , Bangalore 560 066 , India
| | - Kristian E Swearingen
- Institute for Systems Biology , 401 Terry Avenue , North Seattle , Washington 98109 , United States
| | - Santosh Renuse
- Department of Biological Chemistry , Johns Hopkins School of Medicine , 733 N. Broadway , Baltimore , Maryland 21205 , United States
| | - Satish Mishra
- Department of Molecular Microbiology & Immunology , Johns Hopkins Bloomberg School of Public Health , 615 North Wolfe Street , Baltimore , Maryland 21205 , United States
| | - Panga Jaipal Reddy
- Institute for Systems Biology , 401 Terry Avenue , North Seattle , Washington 98109 , United States
| | - Robert L Moritz
- Institute for Systems Biology , 401 Terry Avenue , North Seattle , Washington 98109 , United States
| | - Akhilesh Pandey
- Department of Biological Chemistry , Johns Hopkins School of Medicine , 733 N. Broadway , Baltimore , Maryland 21205 , United States
| | - Photini Sinnis
- Department of Molecular Microbiology & Immunology , Johns Hopkins Bloomberg School of Public Health , 615 North Wolfe Street , Baltimore , Maryland 21205 , United States
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40
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Deletion of Plasmodium falciparum Protein RON3 Affects the Functional Translocation of Exported Proteins and Glucose Uptake. mBio 2019; 10:mBio.01460-19. [PMID: 31289187 PMCID: PMC6747712 DOI: 10.1128/mbio.01460-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The survival of Plasmodium spp. within the host red blood cell (RBC) depends on the function of a membrane protein complex, termed the Plasmodium translocon of exported proteins (PTEX), that exports certain parasite proteins, collectively referred to as the exportome, across the parasitophorous vacuolar membrane (PVM) that encases the parasite in the host RBC cytoplasm. The core of PTEX consists of three proteins: EXP2, PTEX150, and the HSP101 ATPase; of these three proteins, only EXP2 is a membrane protein. Studying the PTEX-dependent transport of members of the exportome, we discovered that exported proteins, such as ring-infected erythrocyte surface antigen (RESA), failed to be transported in parasites in which the parasite rhoptry protein RON3 was conditionally disrupted. RON3-deficient parasites also failed to develop beyond the ring stage, and glucose uptake was significantly decreased. These findings provide evidence that RON3 influences two translocation functions, namely, transport of the parasite exportome through PTEX and the transport of glucose from the RBC cytoplasm to the parasitophorous vacuolar (PV) space where it can enter the parasite via the hexose transporter (HT) in the parasite plasma membrane.IMPORTANCE The malarial parasite within the erythrocyte is surrounded by two membranes. Plasmodium translocon of exported proteins (PTEX) in the parasite vacuolar membrane critically transports proteins from the parasite to the erythrocytic cytosol and membrane to create protein infrastructure important for virulence. The components of PTEX are stored within the dense granule, which is secreted from the parasite during invasion. We now describe a protein, RON3, from another invasion organelle, the rhoptry, that is also secreted during invasion. We find that RON3 is required for the protein transport function of the PTEX and for glucose transport from the RBC cytoplasm to the parasite, a function thought to be mediated by PTEX component EXP2.
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41
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Matthews KM, Kalanon M, de Koning-Ward TF. Uncoupling the Threading and Unfoldase Actions of Plasmodium HSP101 Reveals Differences in Export between Soluble and Insoluble Proteins. mBio 2019; 10:e01106-19. [PMID: 31164473 PMCID: PMC6550532 DOI: 10.1128/mbio.01106-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 12/02/2022] Open
Abstract
Plasmodium parasites must export proteins into their erythrocytic host to survive. Exported proteins must cross the parasite plasma membrane (PPM) and the parasitophorous vacuolar membrane (PVM) encasing the parasite to access the host cell. Crossing the PVM requires protein unfolding and passage through a translocon, the Plasmodium translocon of exported proteins (PTEX). In this study, we provide the first direct evidence that heat shock protein 101 (HSP101), a core component of PTEX, unfolds proteins for translocation across the PVM by creating transgenic Plasmodium parasites in which the unfoldase and translocation functions of HSP101 have become uncoupled. Strikingly, while these parasites could export native proteins, they were unable to translocate soluble, tightly folded reporter proteins bearing the Plasmodium export element (PEXEL) across the PVM into host erythrocytes under the same conditions. In contrast, an identical PEXEL reporter protein but harboring a transmembrane domain could be exported, suggesting that a prior unfolding step occurs at the PPM. Together, these results demonstrate that the export of parasite proteins is dependent on how these proteins are presented to the secretory pathway before they reach PTEX as well as their folded status. Accordingly, only tightly folded soluble proteins secreted into the vacuolar space and not proteins containing transmembrane domains or the majority of erythrocyte-stage exported proteins have an absolute requirement for the full unfoldase activity of HSP101 to be exported.IMPORTANCE The Plasmodium parasites that cause malaria export hundreds of proteins into their host red blood cell (RBC). These exported proteins drastically alter the structural and functional properties of the RBC and play critical roles in parasite virulence and survival. To access the RBC cytoplasm, parasite proteins must pass through the Plasmodium translocon of exported proteins (PTEX) located at the membrane interfacing the parasite and host cell. Our data provide evidence that HSP101, a component of PTEX, serves to unfold protein cargo requiring translocation. We also reveal that addition of a transmembrane domain to soluble cargo influences its ability to be translocated by parasites in which the HSP101 motor and unfolding activities have become uncoupled. Therefore, we propose that proteins with transmembrane domains use an alternative unfolding pathway prior to PTEX to facilitate export.
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Affiliation(s)
| | - Ming Kalanon
- School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
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42
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Schloetel JG, Heine J, Cowman AF, Pasternak M. Guided STED nanoscopy enables super-resolution imaging of blood stage malaria parasites. Sci Rep 2019; 9:4674. [PMID: 30886187 PMCID: PMC6423018 DOI: 10.1038/s41598-019-40718-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/19/2019] [Indexed: 12/27/2022] Open
Abstract
Malaria remains a major burden world-wide, but the disease-causing parasites from the genus Plasmodium are difficult to study in vitro. Owing to the small size of the parasites, subcellular imaging poses a major challenge and the use of super-resolution techniques has been hindered by the parasites' sensitivity to light. This is particularly apparent during the blood-stage of the Plasmodium life cycle, which presents an important target for drug research. The iron-rich food vacuole of the parasite undergoes disintegration when illuminated with high-power lasers such as those required for high resolution in Stimulated Emission Depletion (STED) microscopy. This causes major damage to the sample precluding the use of this super-resolution technique. Here we present guided STED, a novel adaptive illumination (AI) STED approach, which takes advantage of the highly-reflective nature of the iron deposit in the cell to identify the most light-sensitive parts of the sample. Specifically in these parts, the high-power STED laser is deactivated automatically to prevent local damage. Guided STED nanoscopy finally allows super-resolution imaging of the whole Plasmodium life cycle, enabling multicolour imaging of blood-stage malaria parasites with resolutions down to 35 nm without sample destruction.
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Affiliation(s)
| | - Jörn Heine
- Abberior Instruments GmbH, 37077, Göttingen, Germany
| | - Alan F Cowman
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Michał Pasternak
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia.
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43
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Matthews KM, Pitman EL, de Koning-Ward TF. Illuminating how malaria parasites export proteins into host erythrocytes. Cell Microbiol 2019; 21:e13009. [PMID: 30656810 DOI: 10.1111/cmi.13009] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/06/2018] [Accepted: 12/17/2018] [Indexed: 12/11/2022]
Abstract
Plasmodium parasites that cause the disease malaria have developed an elaborate trafficking pathway to facilitate the export of hundreds of effector proteins into their host cell, the erythrocyte. In this review, we outline how certain effector proteins contribute to parasite survival, virulence, and immune evasion. We also highlight how parasite proteins destined for export are recognised at the endoplasmic reticulum to facilitate entry into the export pathway and how the effector proteins are able to transverse the bounding parasitophorous vaculoar membrane via the Plasmodium translocon of exported proteins to gain access to the host cell. Some of the gaps in our understanding of the export pathway are also presented. Finally, we examine the degree of conservation of some of the key components of the Plasmodium export pathway in closely related apicomplexan parasites, which may provide insight into how the diverse apicomplexan parasites have adapted to survival pressures encountered within their respective host cells.
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Affiliation(s)
| | - Ethan L Pitman
- School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
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44
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Siau A, Huang X, Loh HP, Zhang N, Meng W, Sze SK, Renia L, Preiser P. Immunomic Identification of Malaria Antigens Associated With Protection in Mice. Mol Cell Proteomics 2019; 18:837-853. [PMID: 30718293 DOI: 10.1074/mcp.ra118.000997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 01/22/2019] [Indexed: 11/06/2022] Open
Abstract
Efforts to develop vaccines against malaria represent a major research target. The observations that 1) sterile protection can be obtained when the host is exposed to live parasites and 2) the immunity against blood stage parasite is principally mediated by protective antibodies suggest that a protective vaccine is feasible. However, only a small number of proteins have been investigated so far and most of the Plasmodium proteome has yet to be explored. To date, only few immunodominant antigens have emerged for testing in clinical trials but no formulation has led to substantial protection in humans. The nature of parasite molecules associated with protection remains elusive. Here, immunomic screening of mice immune sera with different protection efficiencies against the whole parasite proteome allowed us to identify a large repertoire of antigens validated by screening a library expressing antigens. The calculation of weighted scores reflecting the likelihood of protection of each antigen using five predictive criteria derived from immunomic and proteomic data sets, highlighted a priority list of protective antigens. Altogether, the approach sheds light on conserved antigens across Plasmodium that are amenable to targeting by the host immune system upon merozoite invasion and blood stage development. Most of these antigens have preliminary protection data but have not been widely considered as candidate for vaccine trials, opening new perspectives that overcome the limited choice of immunodominant, poorly protective vaccines currently being the focus of malaria vaccine researches.
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Affiliation(s)
- Anthony Siau
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;.
| | - Ximei Huang
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;; From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Han Ping Loh
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;; From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Neng Zhang
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Wei Meng
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Siu Kwan Sze
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Laurent Renia
- §Singapore Immunology Network (SIgN), A*STAR, Biopolis, Singapore
| | - Peter Preiser
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;.
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Boonyalai N, Collins CR, Hackett F, Withers-Martinez C, Blackman MJ. Essentiality of Plasmodium falciparum plasmepsin V. PLoS One 2018; 13:e0207621. [PMID: 30517136 PMCID: PMC6281190 DOI: 10.1371/journal.pone.0207621] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 11/02/2018] [Indexed: 11/19/2022] Open
Abstract
The malaria parasite replicates within erythrocytes. The pathogenesis of clinical malaria is in large part due to the capacity of the parasite to remodel its host cell. To do this, intraerythrocytic stages of Plasmodium falciparum export more than 300 proteins that dramatically alter the morphology of the infected erythrocyte as well as its mechanical and adhesive properties. P. falciparum plasmepsin V (PfPMV) is an aspartic protease that processes proteins for export into the host erythrocyte and is thought to play a key role in parasite virulence and survival. However, although standard techniques for gene disruption as well as conditional protein knockdown have been previously attempted with the pfpmv gene, complete gene removal or knockdown was not achieved so direct genetic proof that PMV is an essential protein has not been established. Here we have used a conditional gene excision approach combining CRISPR-Cas9 gene editing and DiCre-mediated recombination to functionally inactivate the pfpmv gene. The resulting mutant parasites displayed a severe growth defect. Detailed phenotypic analysis showed that development of the mutant parasites was arrested early in the ring-to-trophozoite transition in the erythrocytic cycle following gene excision. Our findings are the first to elucidate the effects of PMV gene disruption, showing that it is essential for parasite viability in asexual blood stages. The mutant parasites can now be used as a platform to further dissect the Plasmodium protein export pathway.
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Affiliation(s)
- Nonlawat Boonyalai
- Department of Biochemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, Thailand
- * E-mail: (NB), ; (MJB)
| | - 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
| | | | - 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: (NB), ; (MJB)
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Sanders PR, Dickerman BK, Charnaud SC, Ramsland PA, Crabb BS, Gilson PR. The N-terminus of EXP2 forms the membrane-associated pore of the protein exporting translocon PTEX in Plasmodium falciparum. J Biochem 2018; 165:239-248. [DOI: 10.1093/jb/mvy099] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/20/2018] [Indexed: 12/12/2022] Open
Affiliation(s)
| | | | | | - Paul A Ramsland
- Burnet Institute, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
- RMIT University, Bundoora, VIC, Australia
- Monash University, Melbourne, VIC, Australia
| | - Brendan S Crabb
- Burnet Institute, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
- Monash University, Melbourne, VIC, Australia
| | - Paul R Gilson
- Burnet Institute, Melbourne, VIC, Australia
- Monash University, Melbourne, VIC, Australia
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47
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48
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Knockdown of the translocon protein EXP2 in Plasmodium falciparum reduces growth and protein export. PLoS One 2018; 13:e0204785. [PMID: 30439948 PMCID: PMC6237293 DOI: 10.1371/journal.pone.0204785] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/30/2018] [Indexed: 11/23/2022] Open
Abstract
Malaria parasites remodel their host erythrocytes to gain nutrients and avoid the immune system. Host erythrocytes are modified by hundreds of effector proteins exported from the parasite into the host cell. Protein export is mediated by the PTEX translocon comprising five core components of which EXP2 is considered to form the putative pore that spans the vacuole membrane enveloping the parasite within its erythrocyte. To explore the function and importance of EXP2 for parasite survival in the asexual blood stage of Plasmodium falciparum we inducibly knocked down the expression of EXP2. Reduction in EXP2 expression strongly reduced parasite growth proportional to the degree of protein knockdown and tended to stall development about half way through the asexual cell cycle. Once the knockdown inducer was removed and EXP2 expression restored, parasite growth recovered dependent upon the length and degree of knockdown. To establish EXP2 function and hence the basis for growth reduction, the trafficking of an exported protein was monitored following EXP2 knockdown. This resulted in severe attenuation of protein export and is consistent with EXP2, and PTEX in general, being the conduit for export of proteins into the host compartment.
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49
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Matz JM, Matuschewski K. An in silico down-scaling approach uncovers novel constituents of the Plasmodium-containing vacuole. Sci Rep 2018; 8:14055. [PMID: 30232409 PMCID: PMC6145888 DOI: 10.1038/s41598-018-32471-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 09/05/2018] [Indexed: 01/09/2023] Open
Abstract
During blood stage development the malaria parasite resides in a membrane-bound compartment, termed the parasitophorous vacuole (PV). The reasons for this intravacuolar life style and the molecular functions of this parasite-specific compartment remain poorly defined, which is mainly due to our limited knowledge about the molecular make-up of this unique niche. We used an in silico down-scaling approach to select for Plasmodium-specific candidates that harbour signatures of PV residency. Live co-localisation of five endogenously tagged proteins confirmed expression in the PV of Plasmodium berghei blood and liver stages. ER retention was ruled out by addition of the respective carboxyterminal tetrapeptides to a secreted reporter protein. Although all five PV proteins are highly expressed, four proved to be dispensable for parasite development in the mammalian and mosquito host, as revealed by targeted gene deletion. In good agreement with their redundant roles, the knockout parasites displayed no detectable deficiencies in protein export, sequestration, or PV morphology. Together, our approach improved the catalogue of the Plasmodium PV proteome and provides experimental genetics evidence for functional redundancy of several PV proteins.
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Affiliation(s)
- Joachim Michael Matz
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115, Berlin, Germany. .,Parasitology Unit, Max Planck Institute for Infection Biology, 10117, Berlin, Germany.
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115, Berlin, Germany.,Parasitology Unit, Max Planck Institute for Infection Biology, 10117, Berlin, Germany
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50
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Ho CM, Beck JR, Lai M, Cui Y, Goldberg DE, Egea PF, Zhou ZH. Malaria parasite translocon structure and mechanism of effector export. Nature 2018; 561:70-75. [PMID: 30150771 PMCID: PMC6555636 DOI: 10.1038/s41586-018-0469-4] [Citation(s) in RCA: 129] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/19/2018] [Indexed: 12/18/2022]
Abstract
The putative Plasmodium translocon of exported proteins (PTEX) is essential for transport of malarial effector proteins across a parasite-encasing vacuolar membrane into host erythrocytes, but the mechanism of this process remains unknown. Here we show that PTEX is a bona fide translocon by determining structures of the PTEX core complex at near-atomic resolution using cryo-electron microscopy. We isolated the endogenous PTEX core complex containing EXP2, PTEX150 and HSP101 from Plasmodium falciparum in the 'engaged' and 'resetting' states of endogenous cargo translocation using epitope tags inserted using the CRISPR-Cas9 system. In the structures, EXP2 and PTEX150 interdigitate to form a static, funnel-shaped pseudo-seven-fold-symmetric protein-conducting channel spanning the vacuolar membrane. The spiral-shaped AAA+ HSP101 hexamer is tethered above this funnel, and undergoes pronounced compaction that allows three of six tyrosine-bearing pore loops lining the HSP101 channel to dissociate from the cargo, resetting the translocon for the next threading cycle. Our work reveals the mechanism of P. falciparum effector export, and will inform structure-based design of drugs targeting this unique translocon.
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Affiliation(s)
- Chi-Min Ho
- The Molecular Biology Institute, University of California, Los Angeles, CA, USA
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, CA, USA
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Josh R Beck
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Biomedical Sciences, Iowa State University, Ames, IA, USA
| | - Mason Lai
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, CA, USA
| | - Yanxiang Cui
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Daniel E Goldberg
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, MO, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Pascal F Egea
- The Molecular Biology Institute, University of California, Los Angeles, CA, USA.
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
| | - Z Hong Zhou
- The Molecular Biology Institute, University of California, Los Angeles, CA, USA.
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, CA, USA.
- California NanoSystems Institute, University of California, Los Angeles, CA, USA.
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