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Li ZH, Asady B, Chang L, Hortua Triana MA, Li C, Coppens I, Moreno SNJ. Calcium tunneling through the ER and transfer to other organelles for optimal signaling in Toxoplasma gondii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.15.608087. [PMID: 39185237 PMCID: PMC11343207 DOI: 10.1101/2024.08.15.608087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Ca 2+ signaling in cells begins with the opening of Ca 2+ channels in either the plasma membrane (PM) or the endoplasmic reticulum (ER) and results in a dramatic increase in the physiologically low (<100 nM) cytosolic Ca 2+ level. The temporal and spatial Ca 2+ levels are well regulated to enable precise and specific activation of critical biological processes. Ca 2+ signaling regulates pathogenic features of apicomplexan parasites like Toxoplasma gondii which infects approximately one-third of the world's population. T. gondii relies on Ca 2+ signals to stimulate traits of its infection cycle and several Ca 2+ signaling elements play essential roles in its parasitic cycle. Active egress, an essential step for the infection cycle of T. gondii is preceded by a large increase in cytosolic Ca 2+ most likely by release from intracellular stores. Intracellular parasites take up Ca 2+ from the host cell during host Ca 2+ signaling events to replenish intracellular stores. In this work, we investigated the mechanism by which intracellular stores are replenished with Ca 2+ and demonstrated a central role for the SERCA-Ca 2+ -ATPase to keep not only the ER filled with Ca 2+ but also acidic stores. We also show mitochondrial Ca 2+ uptake, by transfer of Ca 2+ from the ER most likely through membrane contact sites. We propose a central role for the ER in tunneling of calcium from the extracellular milieu through the ER to other organelles. HIGHLIGHTS The T. gondii ER efficiently takes up Ca 2+ that enters the cytosol from the extracellular milieu. Filling of acidic stores in T. gondii appears to be dependent on the filling of the ER The mitochondrion of T. gondii has no direct access to extracellular calcium but is able to take up Ca 2+ by transfer from the ER and/or acidic stores.
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2
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Nava MG, Szewczyk J, Arrington JV, Alam T, Vinayak S. The Cryptosporidium signaling kinase CDPK5 plays an important role in male gametogenesis and parasite virulence. Cell Rep 2024; 43:114263. [PMID: 38814783 PMCID: PMC11312397 DOI: 10.1016/j.celrep.2024.114263] [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: 10/03/2023] [Revised: 04/02/2024] [Accepted: 05/07/2024] [Indexed: 06/01/2024] Open
Abstract
The protozoan parasite Cryptosporidium is a leading cause of diarrhea in young children. The parasite's life cycle involves a coordinated and timely progression from asexual to sexual stages, leading to the formation of the transmissible oocyst. Underlying molecular signaling mechanisms orchestrating sexual development are not known. Here, we describe the function of a signaling kinase in Cryptosporidium male gametogenesis. We reveal the expression of Cryptosporidium parvum calcium-dependent protein kinase 5 (CDPK5) during male gamete development and its important role in the egress of mature gametes. Genetic ablation of this kinase results in viable parasites, indicating that this gene is dispensable for parasite survival. Interestingly, cdpk5 deletion decreases parasite virulence and impacts oocyst shedding in immunocompromised mice. Using phosphoproteomics, we identify possible CDPK5 substrates and biological processes regulated by this kinase. Collectively, these findings illuminate parasite cell biology by revealing a mechanism controlling male gamete production and a potential target to block disease transmission.
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Affiliation(s)
- Maria G Nava
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
| | - Joanna Szewczyk
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
| | - Justine V Arrington
- Proteomics Core Facility, Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
| | - Tauqeer Alam
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
| | - Sumiti Vinayak
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA.
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3
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Nayeri T, Sarvi S, Daryani A. Effective factors in the pathogenesis of Toxoplasmagondii. Heliyon 2024; 10:e31558. [PMID: 38818168 PMCID: PMC11137575 DOI: 10.1016/j.heliyon.2024.e31558] [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: 01/03/2023] [Revised: 05/11/2024] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite in humans and animals. It infects about 30 % of the human population worldwide and causes potentially fatal diseases in immunocompromised hosts and neonates. For this study, five English-language databases (ScienceDirect, ProQuest, Web of Science, PubMed, and Scopus) and the internet search engine Google Scholar were searched. This review was accomplished to draw a global perspective of what is known about the pathogenesis of T. gondii and various factors affecting it. Virulence and immune responses can influence the mechanisms of parasite pathogenesis and these factors are in turn influenced by other factors. In addition to the host's genetic background, the type of Toxoplasma strain, the routes of transmission of infection, the number of passages, and different phases of parasite life affect virulence. The identification of virulence factors of the parasite could provide promising insights into the pathogenesis of this parasite. The results of this study can be an incentive to conduct more intensive research to design and develop new anti-Toxoplasma agents (drugs and vaccines) to treat or prevent this infection. In addition, further studies are needed to better understand the key agents in the pathogenesis of T. gondii.
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Affiliation(s)
- Tooran Nayeri
- Infectious and Tropical Diseases Research Center, Dezful University of Medical Sciences, Dezful, Iran
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmad Daryani
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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4
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Valleau D, Sidik SM, Godoy LC, Acevedo‐Sánchez Y, Pasaje CFA, Huynh M, Carruthers VB, Niles JC, Lourido S. A conserved complex of microneme proteins mediates rhoptry discharge in Toxoplasma. EMBO J 2023; 42:e113155. [PMID: 37886905 PMCID: PMC10690463 DOI: 10.15252/embj.2022113155] [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: 11/27/2022] [Revised: 09/19/2023] [Accepted: 09/25/2023] [Indexed: 10/28/2023] Open
Abstract
Apicomplexan parasites discharge specialized organelles called rhoptries upon host cell contact to mediate invasion. The events that drive rhoptry discharge are poorly understood, yet essential to sustain the apicomplexan parasitic life cycle. Rhoptry discharge appears to depend on proteins secreted from another set of organelles called micronemes, which vary in function from allowing host cell binding to facilitation of gliding motility. Here we examine the function of the microneme protein CLAMP, which we previously found to be necessary for Toxoplasma gondii host cell invasion, and demonstrate its essential role in rhoptry discharge. CLAMP forms a distinct complex with two other microneme proteins, the invasion-associated SPATR, and a previously uncharacterized protein we name CLAMP-linked invasion protein (CLIP). CLAMP deficiency does not impact parasite adhesion or microneme protein secretion; however, knockdown of any member of the CLAMP complex affects rhoptry discharge. Phylogenetic analysis suggests orthologs of the essential complex components, CLAMP and CLIP, are ubiquitous across apicomplexans. SPATR appears to act as an accessory factor in Toxoplasma, but despite incomplete conservation is also essential for invasion during Plasmodium falciparum blood stages. Together, our results reveal a new protein complex that mediates rhoptry discharge following host-cell contact.
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Affiliation(s)
| | | | - Luiz C Godoy
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
| | | | | | - My‐Hang Huynh
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Vern B Carruthers
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Jacquin C Niles
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Sebastian Lourido
- Whitehead InstituteCambridgeMAUSA
- Biology DepartmentMassachusetts Institute of TechnologyCambridgeMAUSA
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5
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Shortt E, Hackett CG, Stadler RV, Kent RS, Herneisen AL, Ward GE, Lourido S. CDPK2A and CDPK1 form a signaling module upstream of Toxoplasma motility. mBio 2023; 14:e0135823. [PMID: 37610220 PMCID: PMC10653799 DOI: 10.1128/mbio.01358-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 06/17/2023] [Indexed: 08/24/2023] Open
Abstract
IMPORTANCE This work uncovers interactions between various signaling pathways that govern Toxoplasma gondii egress. Specifically, we compare the function of three canonical calcium-dependent protein kinases (CDPKs) using chemical-genetic and conditional-depletion approaches. We describe the function of a previously uncharacterized CDPK, CDPK2A, in the Toxoplasma lytic cycle, demonstrating that it contributes to parasite fitness through regulation of microneme discharge, gliding motility, and egress from infected host cells. Comparison of analog-sensitive kinase alleles and conditionally depleted alleles uncovered epistasis between CDPK2A and CDPK1, implying a partial functional redundancy. Understanding the topology of signaling pathways underlying key events in the parasite life cycle can aid in efforts targeting kinases for anti-parasitic therapies.
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Affiliation(s)
- Emily Shortt
- Whitehead Institute, Cambridge, Massachusetts, USA
| | | | - Rachel V. Stadler
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| | - Robyn S. Kent
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| | - Alice L. Herneisen
- Whitehead Institute, Cambridge, Massachusetts, USA
- Biology Department, MIT, Cambridge, Massachusetts, USA
| | - Gary E. Ward
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| | - Sebastian Lourido
- Whitehead Institute, Cambridge, Massachusetts, USA
- Biology Department, MIT, Cambridge, Massachusetts, USA
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6
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Arabiotorre A, Bankaitis VA, Grabon A. Regulation of phosphoinositide metabolism in Apicomplexan parasites. Front Cell Dev Biol 2023; 11:1163574. [PMID: 37791074 PMCID: PMC10543664 DOI: 10.3389/fcell.2023.1163574] [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: 02/10/2023] [Accepted: 07/11/2023] [Indexed: 10/05/2023] Open
Abstract
Phosphoinositides are a biologically essential class of phospholipids that contribute to organelle membrane identity, modulate membrane trafficking pathways, and are central components of major signal transduction pathways that operate on the cytosolic face of intracellular membranes in eukaryotes. Apicomplexans (such as Toxoplasma gondii and Plasmodium spp.) are obligate intracellular parasites that are important causative agents of disease in animals and humans. Recent advances in molecular and cell biology of Apicomplexan parasites reveal important roles for phosphoinositide signaling in key aspects of parasitosis. These include invasion of host cells, intracellular survival and replication, egress from host cells, and extracellular motility. As Apicomplexans have adapted to the organization of essential signaling pathways to accommodate their complex parasitic lifestyle, these organisms offer experimentally tractable systems for studying the evolution, conservation, and repurposing of phosphoinositide signaling. In this review, we describe the regulatory mechanisms that control the spatial and temporal regulation of phosphoinositides in the Apicomplexan parasites Plasmodium and T. gondii. We further discuss the similarities and differences presented by Apicomplexan phosphoinositide signaling relative to how these pathways are regulated in other eukaryotic organisms.
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Affiliation(s)
- Angela Arabiotorre
- Department of Cell Biology and Genetics, College of Medicine Texas A&M Health Sciences Center College Station, Bryan, TX, United States
| | - Vytas A. Bankaitis
- Department of Cell Biology and Genetics, College of Medicine Texas A&M Health Sciences Center College Station, Bryan, TX, United States
- Department of Biochemistry and Biophysics Texas A&M University College Station, College Station, TX, United States
- Department of Chemistry Texas A&M University College Station, College Station, TX, United States
| | - Aby Grabon
- Department of Cell Biology and Genetics, College of Medicine Texas A&M Health Sciences Center College Station, Bryan, TX, United States
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7
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O’Shaughnessy WJ, Hu X, Henriquez SA, Reese ML. Toxoplasma ERK7 protects the apical complex from premature degradation. J Cell Biol 2023; 222:e202209098. [PMID: 37027006 PMCID: PMC10083718 DOI: 10.1083/jcb.202209098] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 02/01/2023] [Accepted: 03/17/2023] [Indexed: 04/08/2023] Open
Abstract
Accurate cellular replication balances the biogenesis and turnover of complex structures. In the apicomplexan parasite Toxoplasma gondii, daughter cells form within an intact mother cell, creating additional challenges to ensuring fidelity of division. The apical complex is critical to parasite infectivity and consists of apical secretory organelles and specialized cytoskeletal structures. We previously identified the kinase ERK7 as required for maturation of the apical complex in Toxoplasma. Here, we define the Toxoplasma ERK7 interactome, including a putative E3 ligase, CSAR1. Genetic disruption of CSAR1 fully suppresses loss of the apical complex upon ERK7 knockdown. Furthermore, we show that CSAR1 is normally responsible for turnover of maternal cytoskeleton during cytokinesis, and that its aberrant function is driven by mislocalization from the parasite residual body to the apical complex. These data identify a protein homeostasis pathway critical for Toxoplasma replication and fitness and suggest an unappreciated role for the parasite residual body in compartmentalizing processes that threaten the fidelity of parasite development.
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Affiliation(s)
| | - Xiaoyu Hu
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - Sarah Ana Henriquez
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - Michael L. Reese
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
- Department of Biochemistry, University of Texas, Southwestern Medical Center, Dallas, TX, USA
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8
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Diao Y, Yao Y, El-Ashram S, Bian M. Egress Regulatory Factors: How Toxoplasma Exits from Infected Cells? Pathogens 2023; 12:pathogens12050679. [PMID: 37242349 DOI: 10.3390/pathogens12050679] [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: 03/20/2023] [Revised: 04/29/2023] [Accepted: 05/02/2023] [Indexed: 05/28/2023] Open
Abstract
Toxoplasma gondii is an obligatory intracellular protozoan in the family Apicomplexa. It infects almost one-third of the world's population and causes toxoplasmosis, a prevalent disease. The parasite's egress from infected cells is a key step in the pathology caused by T. gondii. Moreover, T. gondii's continuous infection relies heavily on its capacity to migrate from one cell to another. Many pathways are involved in T. gondii egress. Individual routes may be modified to respond to various environmental stimuli, and many paths can converge. Regardless of the stimuli, the relevance of Ca2+ as a second messenger in transducing these signals, and the convergence of various signaling pathways in the control of motility and, ultimately, egress, is well recognized. This review attempts to outline intra- and extra-parasitic regulators that mediate T. gondii egress, and provides insight into potential clinical interventions and research.
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Affiliation(s)
- Yujie Diao
- Department of Blood Transfusion, The First Affiliated Hospital of Anhui Medical University, Hefei 230032, China
| | - Yong Yao
- College of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Saeed El-Ashram
- College of Life Science and Engineering, Foshan University, 18 Jiangwan Street, Foshan 528231, China
- Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt
| | - Maohong Bian
- Department of Blood Transfusion, The First Affiliated Hospital of Anhui Medical University, Hefei 230032, China
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9
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Santos BMD, Przyborski JM, Garcia CRS. Changes in K + Concentration as a Signaling Mechanism in the Apicomplexa Parasites Plasmodium and Toxoplasma. Int J Mol Sci 2023; 24:ijms24087276. [PMID: 37108438 PMCID: PMC10138558 DOI: 10.3390/ijms24087276] [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: 02/14/2023] [Revised: 04/04/2023] [Accepted: 04/04/2023] [Indexed: 04/29/2023] Open
Abstract
During their life cycle, apicomplexan parasites pass through different microenvironments and encounter a range of ion concentrations. The discovery that the GPCR-like SR25 in Plasmodium falciparum is activated by a shift in potassium concentration indicates that the parasite can take advantage of its development by sensing different ionic concentrations in the external milieu. This pathway involves the activation of phospholipase C and an increase in cytosolic calcium. In the present report, we summarize the information available in the literature regarding the role of potassium ions during parasite development. A deeper understanding of the mechanisms that allow the parasite to cope with ionic potassium changes contributes to our knowledge about the cell cycle of Plasmodium spp.
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Affiliation(s)
- Benedito M Dos Santos
- Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil
| | - Jude M Przyborski
- Department of Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus-Liebig University, 35390 Gießen, Germany
| | - Célia R S Garcia
- Department of Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus-Liebig University, 35390 Gießen, Germany
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10
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Kumar A, Vadas O, Dos Santos Pacheco N, Zhang X, Chao K, Darvill N, Rasmussen HØ, Xu Y, Lin GMH, Stylianou FA, Pedersen JS, Rouse SL, Morgan ML, Soldati-Favre D, Matthews S. Structural and regulatory insights into the glideosome-associated connector from Toxoplasma gondii. eLife 2023; 12:e86049. [PMID: 37014051 PMCID: PMC10125020 DOI: 10.7554/elife.86049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/03/2023] [Indexed: 04/05/2023] Open
Abstract
The phylum of Apicomplexa groups intracellular parasites that employ substrate-dependent gliding motility to invade host cells, egress from the infected cells, and cross biological barriers. The glideosome-associated connector (GAC) is a conserved protein essential to this process. GAC facilitates the association of actin filaments with surface transmembrane adhesins and the efficient transmission of the force generated by myosin translocation of actin to the cell surface substrate. Here, we present the crystal structure of Toxoplasma gondii GAC and reveal a unique, supercoiled armadillo repeat region that adopts a closed ring conformation. Characterisation of the solution properties together with membrane and F-actin binding interfaces suggests that GAC adopts several conformations from closed to open and extended. A multi-conformational model for assembly and regulation of GAC within the glideosome is proposed.
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Affiliation(s)
- Amit Kumar
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | - Oscar Vadas
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of GenevaGenevaSwitzerland
| | - Nicolas Dos Santos Pacheco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of GenevaGenevaSwitzerland
| | - Xu Zhang
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | - Kin Chao
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | - Nicolas Darvill
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | - Helena Ø Rasmussen
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus UniversityAarhusDenmark
| | - Yingqi Xu
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | - Gloria Meng-Hsuan Lin
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of GenevaGenevaSwitzerland
| | | | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus UniversityAarhusDenmark
| | - Sarah L Rouse
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | - Marc L Morgan
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of GenevaGenevaSwitzerland
| | - Stephen Matthews
- Department of Life Sciences, Imperial College LondonLondonUnited Kingdom
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11
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Gui L, O'Shaughnessy WJ, Cai K, Reetz E, Reese ML, Nicastro D. Cryo-tomography reveals rigid-body motion and organization of apicomplexan invasion machinery. Nat Commun 2023; 14:1775. [PMID: 36997532 PMCID: PMC10063558 DOI: 10.1038/s41467-023-37327-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 03/10/2023] [Indexed: 04/03/2023] Open
Abstract
The apical complex is a specialized collection of cytoskeletal and secretory machinery in apicomplexan parasites, which include the pathogens that cause malaria and toxoplasmosis. Its structure and mechanism of motion are poorly understood. We used cryo-FIB-milling and cryo-electron tomography to visualize the 3D-structure of the apical complex in its protruded and retracted states. Averages of conoid-fibers revealed their polarity and unusual nine-protofilament arrangement with associated proteins connecting and likely stabilizing the fibers. Neither the structure of the conoid-fibers nor the architecture of the spiral-shaped conoid complex change during protrusion or retraction. Thus, the conoid moves as a rigid body, and is not spring-like and compressible, as previously suggested. Instead, the apical-polar-rings (APR), previously considered rigid, dilate during conoid protrusion. We identified actin-like filaments connecting the conoid and APR during protrusion, suggesting a role during conoid movements. Furthermore, our data capture the parasites in the act of secretion during conoid protrusion.
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Affiliation(s)
- Long Gui
- Department of Cell Biology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - William J O'Shaughnessy
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - Kai Cai
- Department of Cell Biology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
- Department of Biophysics, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - Evan Reetz
- Department of Cell Biology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - Michael L Reese
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA.
- Department of Biochemistry, University of Texas, Southwestern Medical Center, Dallas, TX, USA.
| | - Daniela Nicastro
- Department of Cell Biology, University of Texas, Southwestern Medical Center, Dallas, TX, USA.
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12
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Huet D, Moreno SNJ. Interorganellar Communication Through Membrane Contact Sites in Toxoplasma Gondii. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2023; 6:25152564231189064. [PMID: 37560622 PMCID: PMC10408353 DOI: 10.1177/25152564231189064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 08/11/2023]
Abstract
Apicomplexan parasites are a group of protists that cause disease in humans and include pathogens like Plasmodium spp., the causative agent of malaria, and Toxoplasma gondii, the etiological agent of toxoplasmosis and one of the most ubiquitous human parasites in the world. Membrane contact sites (MCSs) are widespread structures within eukaryotic cells but their characterization in apicomplexan parasites is only in its very beginnings. Basic biological features of the T. gondii parasitic cycle support numerous organellar interactions, including the transfer of Ca2+ and metabolites between different compartments. In T. gondii, Ca2+ signals precede a series of interrelated molecular processes occurring in a coordinated manner that culminate in the stimulation of key steps of the parasite life cycle. Calcium transfer from the endoplasmic reticulum to other organelles via MCSs would explain the precision, speed, and efficiency that is needed during the lytic cycle of T. gondii. In this short review, we discuss the implications of these structures in cellular signaling, with an emphasis on their potential role in Ca2+ signaling.
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Affiliation(s)
- Diego Huet
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
- Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA, USA
| | - Silvia N. J. Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
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13
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A. PORTES JULIANA, C. VOMMARO ROSSIANE, AYRES CALDAS LUCIO, S. MARTINS-DUARTE ERICA. Intracellular life of protozoan Toxoplasma gondii: Parasitophorous vacuole establishment and survival strategies. BIOCELL 2023. [DOI: 10.32604/biocell.2023.026629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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14
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Sparvoli D, Delabre J, Penarete‐Vargas DM, Kumar Mageswaran S, Tsypin LM, Heckendorn J, Theveny L, Maynadier M, Mendonça Cova M, Berry‐Sterkers L, Guérin A, Dubremetz J, Urbach S, Striepen B, Turkewitz AP, Chang Y, Lebrun M. An apical membrane complex for triggering rhoptry exocytosis and invasion in Toxoplasma. EMBO J 2022; 41:e111158. [PMID: 36245278 PMCID: PMC9670195 DOI: 10.15252/embj.2022111158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 09/13/2022] [Accepted: 09/19/2022] [Indexed: 01/13/2023] Open
Abstract
Apicomplexan parasites possess secretory organelles called rhoptries that undergo regulated exocytosis upon contact with the host. This process is essential for the parasitic lifestyle of these pathogens and relies on an exocytic machinery sharing structural features and molecular components with free-living ciliates. However, how the parasites coordinate exocytosis with host interaction is unknown. Here, we performed a Tetrahymena-based transcriptomic screen to uncover novel exocytic factors in Ciliata and conserved in Apicomplexa. We identified membrane-bound proteins, named CRMPs, forming part of a large complex essential for rhoptry secretion and invasion in Toxoplasma. Using cutting-edge imaging tools, including expansion microscopy and cryo-electron tomography, we show that, unlike previously described rhoptry exocytic factors, TgCRMPs are not required for the assembly of the rhoptry secretion machinery and only transiently associate with the exocytic site-prior to the invasion. CRMPs and their partners contain putative host cell-binding domains, and CRMPa shares similarities with GPCR proteins. Collectively our data imply that the CRMP complex acts as a host-molecular sensor to ensure that rhoptry exocytosis occurs when the parasite contacts the host cell.
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Affiliation(s)
- Daniela Sparvoli
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Jason Delabre
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | | | - Shrawan Kumar Mageswaran
- Department of Biochemistry and Biophysics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Lev M Tsypin
- Department of Molecular Genetics and Cell BiologyUniversity of ChicagoChicagoILUSA
- Present address:
Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCAUSA
| | - Justine Heckendorn
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Liam Theveny
- Department of Biochemistry and Biophysics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Marjorie Maynadier
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Marta Mendonça Cova
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Laurence Berry‐Sterkers
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Amandine Guérin
- Department of Pathobiology, School of Veterinary MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Jean‐François Dubremetz
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Serge Urbach
- IGFUniversité de Montpellier, CNRS, INSERMMontpellierFrance
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Aaron P Turkewitz
- Department of Molecular Genetics and Cell BiologyUniversity of ChicagoChicagoILUSA
| | - Yi‐Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Maryse Lebrun
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
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15
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Vo KC, Ruga L, Psathaki OE, Franzkoch R, Distler U, Tenzer S, Hensel M, Hegemann P, Gupta N. Plasticity and therapeutic potential of cAMP and cGMP-specific phosphodiesterases in Toxoplasma gondii. Comput Struct Biotechnol J 2022; 20:5775-5789. [PMID: 36382189 PMCID: PMC9619220 DOI: 10.1016/j.csbj.2022.09.022] [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: 05/31/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 11/03/2022] Open
Abstract
Toxoplasma gondii is a common zoonotic protozoan pathogen adapted to intracellular parasitism in many host cells of diverse organisms. Our previous work has identified 18 cyclic nucleotide phosphodiesterase (PDE) proteins encoded by the parasite genome, of which 11 are expressed during the lytic cycle of its acutely-infectious tachyzoite stage in human cells. Here, we show that ten of these enzymes are promiscuous dual-specific phosphodiesterases, hydrolyzing cAMP and cGMP. TgPDE1 and TgPDE9, with a Km of 18 μM and 31 μM, respectively, are primed to hydrolyze cGMP, whereas TgPDE2 is highly specific to cAMP (Km, 14 μM). Immuno-electron microscopy revealed various subcellular distributions of TgPDE1, 2, and 9, including in the inner membrane complex, apical pole, plasma membrane, cytosol, dense granule, and rhoptry, indicating spatial control of signaling within tachyzoites. Notably, despite shared apical location and dual-catalysis, TgPDE8 and TgPDE9 are fully dispensable for the lytic cycle and show no functional redundancy. In contrast, TgPDE1 and TgPDE2 are individually required for optimal growth, and their collective loss is lethal to the parasite. In vitro phenotyping of these mutants revealed the roles of TgPDE1 and TgPDE2 in proliferation, gliding motility, invasion and egress of tachyzoites. Moreover, our enzyme inhibition assays in conjunction with chemogenetic phenotyping underpin TgPDE1 as a target of commonly-used PDE inhibitors, BIPPO and zaprinast. Finally, we identified a retinue of TgPDE1 and TgPDE2-interacting kinases and phosphatases, possibly regulating the enzymatic activity. In conclusion, our datasets on the catalytic function, physiological relevance, subcellular localization and drug inhibition of key phosphodiesterases highlight the previously-unanticipated plasticity and therapeutic potential of cyclic nucleotide signaling in T. gondii.
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Key Words
- 3′IT, 3′-insertional tagging
- Apicomplexa
- COS, crossover sequence
- CRISPR, clustered regularly interspaced short palindromic repeats
- DHFR-TS, dihydrofolate reductase – thymidylate synthase
- HFF, human foreskin fibroblast
- HXGPRT, hypoxanthine-xanthine-guanine phosphoribosyl transferase
- IMC, inner membrane complex
- Lytic cycle
- MoI, multiplicity of infection
- PDE, phosphodiesterase
- PKA, protein kinase A
- PKG, protein kinase G
- PM, plasma membrane
- Phosphodiesterase
- S. C., selection cassette
- TEM, transmission electron microscopy
- Tachyzoite
- cAMP & cGMP signaling
- sgRNA, single guide RNA
- smHA, spaghetti monster-HA
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Affiliation(s)
- Kim Chi Vo
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Liberta Ruga
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Olympia Ekaterini Psathaki
- University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Integrated Bioimaging Faciltiy (iBiOs), Germany
| | - Rico Franzkoch
- University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Integrated Bioimaging Faciltiy (iBiOs), Germany
| | - Ute Distler
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Michael Hensel
- University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Integrated Bioimaging Faciltiy (iBiOs), Germany
| | - Peter Hegemann
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-P), Hyderabad, India
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16
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Segev-Zarko LA, Dahlberg PD, Sun SY, Pelt DM, Kim CY, Egan ES, Sethian JA, Chiu W, Boothroyd JC. Cryo-electron tomography with mixed-scale dense neural networks reveals key steps in deployment of Toxoplasma invasion machinery. PNAS NEXUS 2022; 1:pgac183. [PMID: 36329726 PMCID: PMC9615128 DOI: 10.1093/pnasnexus/pgac183] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/30/2022] [Indexed: 01/29/2023]
Abstract
Host cell invasion by intracellular, eukaryotic parasites within the phylum Apicomplexa is a remarkable and active process involving the coordinated action of apical organelles and other structures. To date, capturing how these structures interact during invasion has been difficult to observe in detail. Here, we used cryogenic electron tomography to image the apical complex of Toxoplasma gondii tachyzoites under conditions that mimic resting parasites and those primed to invade through stimulation with calcium ionophore. Through the application of mixed-scale dense networks for image processing, we developed a highly efficient pipeline for annotation of tomograms, enabling us to identify and extract densities of relevant subcellular organelles and accurately analyze features in 3-D. The results reveal a dramatic change in the shape of the anteriorly located apical vesicle upon its apparent fusion with a rhoptry that occurs only in the stimulated parasites. We also present information indicating that this vesicle originates from the vesicles that parallel the intraconoidal microtubules and that the latter two structures are linked by a novel tether. We show that a rosette structure previously proposed to be involved in rhoptry secretion is associated with apical vesicles beyond just the most anterior one. This result, suggesting multiple vesicles are primed to enable rhoptry secretion, may shed light on the mechanisms Toxoplasma employs to enable repeated invasion attempts. Using the same approach, we examine Plasmodium falciparum merozoites and show that they too possess an apical vesicle just beneath a rosette, demonstrating evolutionary conservation of this overall subcellular organization.
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Affiliation(s)
- Li-av Segev-Zarko
- Department of Microbiology and Immunology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA
| | - Peter D Dahlberg
- Department of Chemistry, Stanford University, 450 Serra Mall, Stanford, CA 94305, USA
| | - Stella Y Sun
- Department of Bioengineering, Stanford University, 450 Serra Mall, Stanford, CA 94305, USA,Department of Structural Biology, University of Pittsburgh, 4200 Fifth Ave, Pittsburgh, PA 15260, USA
| | - Daniël M Pelt
- Leiden Institute of Advanced Computer Science, Leiden University, Rapenburg 70, 2311 EZ Leiden, The Netherlands
| | - Chi Yong Kim
- Department of Microbiology and Immunology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA,Department of Pediatrics––Infectious Diseases, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA
| | - Elizabeth S Egan
- Department of Microbiology and Immunology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA,Department of Pediatrics––Infectious Diseases, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA
| | - James A Sethian
- Department of Mathematics, University of California, Berkeley, CA 94720, USA,Center for Advanced Mathematics for Energy Research Application (CAMERA), Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720, USA
| | - Wah Chiu
- To whom correspondence should be addressed:
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17
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Fibrillarin RNA methylase is an interacting protein of Cryptosporidium parvum calmodulin-like protein (CpCML). Microb Pathog 2022; 170:105679. [PMID: 35843442 DOI: 10.1016/j.micpath.2022.105679] [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: 03/02/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 11/23/2022]
Abstract
Cryptosporidium parvum is an obligate protozoan parasite invading epithelial cells of small intestine of human and animals, and causing diarrheal disease. In apicomplexan parasites, calcium signaling can regulate many essential biological processes such as invasion and migration. As the main intracellular receptor for calcium ions, calmodulins control the activities of hundreds of enzymes and proteins. Calmodulin-like protein (CML) is an important member of the calmodulin family and may play a key role in C. parvum, however, the actual situation is still not clear. The present study aimed to identify the parasite interaction partner proteins of C. parvum calmodulin-like protein (CpCML). By constructing the cpcml bait plasmid, 5 potential CpCML - interacting proteins in C. parvum oocyst were screened by yeast-two-hybrid system (Y2H). Bimolecular fluorescence complementation (BiFC) and Co-immunoprecipitation (Co-IP) were performed as subsequent validations. Fibrillarin RNA methylase (FBL) was identified via this screening method as CpCML interacting protein in C. parvum. The identification of this interaction made it possible to get a further understanding of the function of CpCML and its contribution to the pathogenicity of C. parvum.
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18
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Onzere CK, Fry LM, Bishop RP, Da Silva M, Madsen-Bouterse SA, Bastos RG, Knowles DP, Suarez CE. Theileria equi RAP-1a and RAP-1b proteins contain immunoreactive epitopes and are suitable candidates for vaccine and diagnostics development. Int J Parasitol 2022; 52:385-397. [DOI: 10.1016/j.ijpara.2022.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 11/16/2022]
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19
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Fu Y, Brown KM, Jones NG, Moreno SNJ, Sibley LD. Toxoplasma bradyzoites exhibit physiological plasticity of calcium and energy stores controlling motility and egress. eLife 2021; 10:e73011. [PMID: 34860156 PMCID: PMC8683080 DOI: 10.7554/elife.73011] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 12/03/2021] [Indexed: 01/01/2023] Open
Abstract
Toxoplasma gondii has evolved different developmental stages for disseminating during acute infection (i.e., tachyzoites) and establishing chronic infection (i.e., bradyzoites). Calcium ion (Ca2+) signaling tightly regulates the lytic cycle of tachyzoites by controlling microneme secretion and motility to drive egress and cell invasion. However, the roles of Ca2+ signaling pathways in bradyzoites remain largely unexplored. Here, we show that Ca2+ responses are highly restricted in bradyzoites and that they fail to egress in response to agonists. Development of dual-reporter parasites revealed dampened Ca2+ responses and minimal microneme secretion by bradyzoites induced in vitro or harvested from infected mice and tested ex vivo. Ratiometric Ca2+ imaging demonstrated lower Ca2+ basal levels, reduced magnitude, and slower Ca2+ kinetics in bradyzoites compared with tachyzoites stimulated with agonists. Diminished responses in bradyzoites were associated with downregulation of Ca2+-ATPases involved in intracellular Ca2+ storage in the endoplasmic reticulum (ER) and acidocalcisomes. Once liberated from cysts by trypsin digestion, bradyzoites incubated in glucose plus Ca2+ rapidly restored their intracellular Ca2+ and ATP stores, leading to enhanced gliding. Collectively, our findings indicate that intracellular bradyzoites exhibit dampened Ca2+ signaling and lower energy levels that restrict egress, and yet upon release they rapidly respond to changes in the environment to regain motility.
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Affiliation(s)
- Yong Fu
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
| | - Kevin M Brown
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
| | - Nathaniel G Jones
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
| | - Silvia NJ Moreno
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of GeorgiaAthensUnited States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
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20
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Lodoen MB, Smith NC, Soldati-Favre D, Ferguson DJP, van Dooren GG. Nanos gigantium humeris insidentes: old papers informing new research into Toxoplasma gondii. Int J Parasitol 2021; 51:1193-1212. [PMID: 34736901 PMCID: PMC10538201 DOI: 10.1016/j.ijpara.2021.10.004] [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: 09/14/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 11/25/2022]
Abstract
Since Nicolle, Manceaux and Splendore first described Toxoplasma gondii as a parasite of rodents and rabbits in the early 20th century, a diverse and vigorous research community has been built around studying this fascinating intracellular parasite. In addition to its importance as a pathogen of humans, livestock and wildlife, modern researchers are attracted to T. gondii as a facile experimental system to study many aspects of evolutionary biology, cellular biology, host-microbe interactions, and host immunity. For new researchers entering the field, the extensive literature describing the biology of the parasite, and the interactions with its host, can be daunting. In this review, we examine four foundational studies that describe various aspects of T. gondii biology, presenting a 'journal club'-style analysis of each. We have chosen a paper that established the beguiling life cycle of the parasite (Hutchison et al., 1971), a paper that described key features of its cellular biology that the parasite shares with related organisms (Gustafson et al., 1954), a paper that characterised the origin of the unique compartment in which the parasite resides within host cells (Jones and Hirsch, 1972), and a paper that established a key mechanism in the host immune response to parasite infection (Pfefferkorn, 1984). These interesting and far-reaching studies set the stage for subsequent research into numerous facets of parasite biology. As well as providing new researchers with an entry point into the literature surrounding the parasite, revisiting these studies can remind us of the roots of our discipline, how far we have come, and the new directions in which we might head.
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Affiliation(s)
- Melissa B Lodoen
- Institute for Immunology, University of California, Irvine, Irvine, CA, USA; Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California, USA
| | - Nicholas C Smith
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia; Research School of Biology, Australian National University, Canberra, ACT 2600, Australia
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland
| | - David J P Ferguson
- Nuffield Department of Clinical Laboratory Science, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK; Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP, UK
| | - Giel G van Dooren
- Research School of Biology, Australian National University, Canberra, ACT 2600, Australia.
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21
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Huynh MH, Roiko MS, Gomes AO, Schinke EN, Schultz AJ, Agrawal S, Oellig CA, Sexton TR, Beauchamp JM, Laliberté J, Sivaraman KK, Hersh LB, McGowan S, Carruthers VB. Toxoplasma gondii Toxolysin 4 Contributes to Efficient Parasite Egress from Host Cells. mSphere 2021; 6:e0044421. [PMID: 34190588 PMCID: PMC8265663 DOI: 10.1128/msphere.00444-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 06/09/2021] [Indexed: 11/24/2022] Open
Abstract
Egress from host cells is an essential step in the lytic cycle of T. gondii and other apicomplexan parasites; however, only a few parasite secretory proteins are known to affect this process. The putative metalloproteinase toxolysin 4 (TLN4) was previously shown to be an extensively processed microneme protein, but further characterization was impeded by the inability to genetically ablate TLN4. Here, we show that TLN4 has the structural properties of an M16 family metalloproteinase, that it possesses proteolytic activity on a model substrate, and that genetic disruption of TLN4 reduces the efficiency of egress from host cells. Complementation of the knockout strain with the TLN4 coding sequence significantly restored egress competency, affirming that the phenotype of the Δtln4 parasite was due to the absence of TLN4. This work identifies TLN4 as the first metalloproteinase and the second microneme protein to function in T. gondii egress. The study also lays a foundation for future mechanistic studies defining the precise role of TLN4 in parasite exit from host cells. IMPORTANCE After replicating within infected host cells, the single-celled parasite Toxoplasma gondii must rupture out of such cells in a process termed egress. Although it is known that T. gondii egress is an active event that involves disruption of host-derived membranes surrounding the parasite, very few proteins that are released by the parasite are known to facilitate egress. In this study, we identify a parasite secretory protease that is necessary for efficient and timely egress, laying the foundation for understanding precisely how this protease facilitates T. gondii exit from host cells.
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Affiliation(s)
- My-Hang Huynh
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Marijo S. Roiko
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Angelica O. Gomes
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Ellyn N. Schinke
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Aric J. Schultz
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Swati Agrawal
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Christine A. Oellig
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Travis R. Sexton
- Department of Cardiology, University of Kentucky, Lexington, Kentucky, USA
| | - Jessica M. Beauchamp
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Julie Laliberté
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Komagal Kannan Sivaraman
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Louis B. Hersh
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, Kentucky, USA
| | - Sheena McGowan
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Vern B. Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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22
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Zhu J, Wang Y, Cao Y, Shen J, Yu L. Diverse Roles of TgMIC1/4/6 in the Toxoplasma Infection. Front Microbiol 2021; 12:666506. [PMID: 34220751 PMCID: PMC8247436 DOI: 10.3389/fmicb.2021.666506] [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: 02/10/2021] [Accepted: 05/25/2021] [Indexed: 11/23/2022] Open
Abstract
Toxoplasma gondii microneme is a specialized secretory organelle that discharges its contents at the apical tip of this apicomplexan parasite in a sequential and regulated manner. Increasing number of studies on microneme proteins (MICs) have shown them as a predominant and important role in host cell attachment, invasion, motility and pathogenesis. In this review, we summarize the research advances in one of the most important MICs complexes, TgMIC1/4/6, which will contribute to improve the understanding of the molecular mechanism of T. gondii infection and provide a theoretical basis for the effective control against T. gondii.
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Affiliation(s)
- Jinjin Zhu
- The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Department of Microbiology and Parasitology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Yang Wang
- The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Department of Microbiology and Parasitology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Yuanyuan Cao
- The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Department of Microbiology and Parasitology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Jilong Shen
- The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Department of Microbiology and Parasitology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Li Yu
- The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Department of Microbiology and Parasitology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
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23
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Sparvoli D, Lebrun M. Unraveling the Elusive Rhoptry Exocytic Mechanism of Apicomplexa. Trends Parasitol 2021; 37:622-637. [PMID: 34045149 DOI: 10.1016/j.pt.2021.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 12/11/2022]
Abstract
Apicomplexan parasites are unicellular eukaryotes that invade the cells in which they proliferate. The development of genetic tools in Toxoplasma, and then in Plasmodium, in the 1990s allowed the first description of the molecular machinery used for motility and invasion, revealing a crucial role for two different secretory organelles, micronemes and rhoptries. Rhoptry proteins are injected directly into the host cytoplasm not only to promote invasion but also to manipulate host functions. Nonetheless, the injection machinery has remained mysterious, a major conundrum in the field. Here we review recent progress in uncovering structural components and proteins implicated in rhoptry exocytosis and explain how revisiting early findings and considering the evolutionary origins of Apicomplexa contributed to some of these discoveries.
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Affiliation(s)
- Daniela Sparvoli
- LPHI UMR5235, Univ Montpellier, CNRS, F-34095 Montpellier, France
| | - Maryse Lebrun
- LPHI UMR5235, Univ Montpellier, CNRS, F-34095 Montpellier, France.
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24
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Wang Y, Han C, Zhou R, Zhu J, Zhang F, Li J, Luo Q, Du J, Chu D, Cai Y, Shen J, Yu L. Differential expression of TgMIC1 in isolates of Chinese 1 Toxoplasma with different virulence. Parasit Vectors 2021; 14:253. [PMID: 33985552 PMCID: PMC8117571 DOI: 10.1186/s13071-021-04752-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 04/28/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The predominant genotype of Toxoplasma in China is the Chinese 1 (ToxoDB#9) lineage. TgCtwh3 and TgCtwh6 are two representative strains of Chinese 1, exhibiting high and low virulence to mice, respectively. Little is known regarding the virulence mechanism of this non-classical genotype. Our previous RNA sequencing data revealed differential mRNA levels of TgMIC1 in TgCtwh3 and TgCtwh6. We aim to further confirm the differential expression of TgMIC1 and its significance in this atypical genotype. METHODS Quantitative real-time PCR was used to verify the RNA sequencing data; then, polyclonal antibodies against TgMIC1 were prepared and identified. Moreover, the invasion and proliferation of the parasite in HFF cells were observed after treatment with TgMIC1 polyclonal antibody or not. RESULTS The data showed that the protein level of TgMIC1 was significantly higher in high-virulence strain TgCtwh3 than in low-virulence strain TgCtwh6 and that the invasion and proliferation of TgCtwh3 were inhibited by TgMIC1 polyclonal antibody. CONCLUSION Differential expression of TgMIC1 in TgCtwh3 and TgCtwh6 may explain, at least partly, the virulence mechanism of this atypical genotype.
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Affiliation(s)
- Yang Wang
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China
| | - Chengjian Han
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China.,The Clinical Laboratory of the Third People's Hospital of Heifei, Hefei, China
| | - Rongsheng Zhou
- The Clinical Laboratory of the Third People's Hospital of Heifei, Hefei, China
| | - Jinjin Zhu
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China
| | - Famin Zhang
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China
| | - Jingyang Li
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China.,The Clinical Laboratory of the Third People's Hospital of Heifei, Hefei, China
| | - Qingli Luo
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China
| | - Jian Du
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China.,Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, China
| | - Deyong Chu
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China
| | - Yihong Cai
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China.,Department of Health Inspection and Quarantine, School of Public Health, Anhui Medical University, Hefei, China
| | - Jilong Shen
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China
| | - Li Yu
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Anhui Key Laboratory of Zoonoses, School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, 230032, Anhui Province, People's Republic of China.
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25
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Gaji RY, Sharp AK, Brown AM. Protein kinases in Toxoplasma gondii. Int J Parasitol 2021; 51:415-429. [PMID: 33581139 PMCID: PMC11065138 DOI: 10.1016/j.ijpara.2020.11.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/10/2020] [Accepted: 11/15/2020] [Indexed: 02/06/2023]
Abstract
Toxoplasma gondii is an obligatory intracellular pathogen that causes life threatening illness in immunodeficient individuals, miscarriage in pregnant woman, and blindness in newborn children. Similar to any other eukaryotic cell, protein kinases play critical and essential roles in the Toxoplasma life cycle. Accordingly, many studies have focused on identifying and defining the mechanism of function of these signalling proteins with a long-term goal to develop anti-Toxoplasma therapeutics. In this review, we briefly discuss classification and key components of the catalytic domain which are critical for functioning of kinases, with a focus on domains, families, and groups of kinases within Toxoplasma. More importantly, this article provides a comprehensive, current overview of research on kinase groups in Toxoplasma including the established eukaryotic AGC, CAMK, CK1, CMGC, STE, TKL families and the apicomplexan-specific FIKK, ROPK and WNG family of kinases. This work provides an overview and discusses current knowledge on Toxoplasma kinases including their localization, function, signalling network and role in acute and chronic pathogenesis, with a view towards the future in probing kinases as viable drug targets.
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Affiliation(s)
- Rajshekhar Y Gaji
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech University, Blacksburg, VA, USA; Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA.
| | - Amanda K Sharp
- Interdisciplinary Program in Genetics, Bioinformatics, and Computational Biology, Virginia Tech, Blacksburg, VA, USA
| | - Anne M Brown
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA; University Libraries, Virginia Tech, Blacksburg, VA, USA
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26
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Theileria equi claudin like apicomplexan microneme protein contains neutralization-sensitive epitopes and interacts with components of the equine erythrocyte membrane skeleton. Sci Rep 2021; 11:9301. [PMID: 33927329 PMCID: PMC8085155 DOI: 10.1038/s41598-021-88902-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 04/16/2021] [Indexed: 11/19/2022] Open
Abstract
Theileria equi is a widely distributed apicomplexan parasite that causes severe hemolytic anemia in equid species. There is currently no effective vaccine for control of the parasite and understanding the mechanism that T. equi utilizes to invade host cells may be crucial for vaccine development. Unlike most apicomplexan species studied to date, the role of micronemes in T. equi invasion of host cells is unknown. We therefore assessed the role of the T. equi claudin-like apicomplexan microneme protein (CLAMP) in the invasion of equine erythrocytes as a first step towards understanding the role of this organelle in the parasite. Our findings show that CLAMP is expressed in the merozoite and intra-erythrocytic developmental stages of T. equi and in vitro neutralization experiments suggest that the protein is involved in erythrocyte invasion. Proteomic analyses indicate that CLAMP interacts with the equine erythrocyte α-and β- spectrin chains in the initial stages of T. equi invasion and maintains these interactions while also associating with the anion-exchange protein, tropomyosin 3, band 4.1 and cytoplasmic actin 1 after invasion. Additionally, serological analyses show that T. equi-infected horses mount robust antibody responses against CLAMP indicating that the protein is immunogenic and therefore represents a potential vaccine candidate.
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27
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Abstract
Micronemes are specialized secretory organelles present in all motile forms of apicomplexan parasites. Microneme vesicles hold adhesins and other proteins that are secreted to facilitate parasite attachment, invasion of host cells, and egress following replication-all processes indispensable for cell-to-cell transmission of these obligate intracellular parasites. Defining the signaling pathways that lead to microneme secretion is an important part of understanding the infectious cycle of apicomplexan parasites. However, the classical method of measuring microneme secretion by immunoblotting for microneme proteins in parasite excreted/secreted antigen (ESA) preparations is low-throughput and only semiquantitative. We recently reported a new luciferase-based method for measuring microneme secretion in a 96-well format with high sensitivity in the model apicomplexan Toxoplasma gondii. Here, we aim to elaborate on this detection method and review current practices for stimulating microneme secretion in vitro.
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28
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Elsworth B, Duraisingh MT. A framework for signaling throughout the life cycle of Babesia species. Mol Microbiol 2020; 115:882-890. [PMID: 33274587 DOI: 10.1111/mmi.14650] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 01/28/2023]
Abstract
Babesia species are tick-borne intracellular parasites that infect the red blood cells of their mammalian host, leading to severe or fatal disease. Babesia spp. infect a wide range of mammalian species and cause a significant economic burden globally, predominantly through disease in cattle. Several Babesia spp. are increasingly being recognized as zoonotic pathogens of humans. Babesia spp. have complex life cycles involving multiple stages in the tick and the mammalian host. The parasite utilizes complex signaling pathways during replication, egress, and invasion in each of these stages. They must also rapidly respond to their environment when switching between the mammalian and tick stages. This review will focus on the signaling pathways and environmental stimuli that Babesia spp. utilize in the bloodstream and for transmission to the tick, with an emphasis on the role of phosphorylation- and calcium-based signaling during egress and invasion. The expanding availability of in vitro and in vivo culture systems, genomes, transcriptomes, and transgenic systems available for a range of Babesia spp. should encourage further biological and translational studies of these ubiquitous parasites.
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Affiliation(s)
- Brendan Elsworth
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
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29
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Bisio H, Soldati-Favre D. Signaling Cascades Governing Entry into and Exit from Host Cells by Toxoplasma gondii. Annu Rev Microbiol 2020; 73:579-599. [PMID: 31500539 DOI: 10.1146/annurev-micro-020518-120235] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Apicomplexa phylum includes a large group of obligate intracellular protozoan parasites responsible for important diseases in humans and animals. Toxoplasma gondii is a widespread parasite with considerable versatility, and it is capable of infecting virtually any warm-blooded animal, including humans. This outstanding success can be attributed at least in part to an efficient and continuous sensing of the environment, with a ready-to-adapt strategy. This review updates the current understanding of the signals governing the lytic cycle of T. gondii, with particular focus on egress from infected cells, a key step for balancing survival, multiplication, and spreading in the host. We cover the recent advances in the conceptual framework of regulation of microneme exocytosis that ensures egress, motility, and invasion. Particular emphasis is given to the trigger molecules and signaling cascades regulating exit from host cells.
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Affiliation(s)
- Hugo Bisio
- Département de Microbiologie et Médecine Moléculaire, Centre Médical Universitaire, Université de Genève, 1211 Geneva 4, Switzerland;
| | - Dominique Soldati-Favre
- Département de Microbiologie et Médecine Moléculaire, Centre Médical Universitaire, Université de Genève, 1211 Geneva 4, Switzerland;
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30
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Ancient MAPK ERK7 is regulated by an unusual inhibitory scaffold required for Toxoplasma apical complex biogenesis. Proc Natl Acad Sci U S A 2020; 117:12164-12173. [PMID: 32409604 PMCID: PMC7275706 DOI: 10.1073/pnas.1921245117] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Apicomplexan parasites include organisms that cause widespread and devastating human diseases such as malaria, cryptosporidiosis, and toxoplasmosis. These parasites are named for a structure, called the “apical complex,” that organizes their invasion and secretory machinery. We found that two proteins, apical cap protein 9 (AC9) and an enzyme called ERK7, work together to facilitate apical complex assembly. Intriguingly, ERK7 is an ancient molecule that is found throughout Eukaryota, though its regulation and function are poorly understood. AC9 is a scaffold that concentrates ERK7 at the base of the developing apical complex. In addition, AC9 binding likely confers substrate selectivity upon ERK7. This simple competitive regulatory model may be a powerful but largely overlooked mechanism throughout biology. Apicomplexan parasites use a specialized cilium structure called the apical complex to organize their secretory organelles and invasion machinery. The apical complex is integrally associated with both the parasite plasma membrane and an intermediate filament cytoskeleton called the inner-membrane complex (IMC). While the apical complex is essential to the parasitic lifestyle, little is known about the regulation of apical complex biogenesis. Here, we identify AC9 (apical cap protein 9), a largely intrinsically disordered component of the Toxoplasma gondii IMC, as essential for apical complex development, and therefore for host cell invasion and egress. Parasites lacking AC9 fail to successfully assemble the tubulin-rich core of their apical complex, called the conoid. We use proximity biotinylation to identify the AC9 interaction network, which includes the kinase extracellular signal-regulated kinase 7 (ERK7). Like AC9, ERK7 is required for apical complex biogenesis. We demonstrate that AC9 directly binds ERK7 through a conserved C-terminal motif and that this interaction is essential for ERK7 localization and function at the apical cap. The crystal structure of the ERK7–AC9 complex reveals that AC9 is not only a scaffold but also inhibits ERK7 through an unusual set of contacts that displaces nucleotide from the kinase active site. ERK7 is an ancient and autoactivating member of the mitogen-activated kinase (MAPK) family and its regulation is poorly understood in all organisms. We propose that AC9 dually regulates ERK7 by scaffolding and concentrating it at its site of action while maintaining it in an “off” state until the specific binding of a true substrate.
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31
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O’Shaughnessy WJ, Hu X, Beraki T, McDougal M, Reese ML. Loss of a conserved MAPK causes catastrophic failure in assembly of a specialized cilium-like structure in Toxoplasma gondii. Mol Biol Cell 2020; 31:881-888. [PMID: 32073987 PMCID: PMC7185968 DOI: 10.1091/mbc.e19-11-0607] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/03/2020] [Accepted: 02/14/2020] [Indexed: 12/26/2022] Open
Abstract
Primary cilia are important organizing centers that control diverse cellular processes. Apicomplexan parasites like Toxoplasma gondii have a specialized cilium-like structure called the conoid that organizes the secretory and invasion machinery critical for the parasites' lifestyle. The proteins that initiate the biogenesis of this structure are largely unknown. We identified the Toxoplasma orthologue of the conserved kinase ERK7 as essential to conoid assembly. Parasites in which ERK7 has been depleted lose their conoids late during maturation and are immotile and thus unable to invade new host cells. This is the most severe phenotype to conoid biogenesis yet reported, and is made more striking by the fact that ERK7 is not a conoid protein, as it localizes just basal to the structure. ERK7 has been recently implicated in ciliogenesis in metazoan cells, and our data suggest that this kinase has an ancient and central role in regulating ciliogenesis throughout Eukaryota.
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Affiliation(s)
| | - Xiaoyu Hu
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Tsebaot Beraki
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Matthew McDougal
- Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Michael L. Reese
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390
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32
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The effect of edelfosine on GRA1 and MIC3 expressions in acute toxoplasmosis. Parasitol Res 2020; 119:1371-1380. [PMID: 31970471 DOI: 10.1007/s00436-020-06601-x] [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: 11/12/2019] [Accepted: 01/06/2020] [Indexed: 10/25/2022]
Abstract
Phosphoinositide-dependent phospholipase-C (PI-PLC) triggers the calcium signaling pathway which plays an important role in dense granule and microneme secretion and pathogenesis of Toxoplasma gondii (T. gondii). There are limited data about the effects of phospholipid analogues against T. gondii. The current study assessed the effect of edelfosine, as a phospholipid analogue, on GRA1 and MIC3 expressions using in vitro and in vivo models of acute toxoplasmosis. Infected Vero cells were treated by edelfosine in two subgroups: 24 h following the cell infection and treatment at the same time of cell infection. Animal study was performed on forty mice in four groups including non-infected, infected untreated, infected edelfosine-treated, and infected pyrimethamine-treated. Gene and protein expression analyses were done using quantitative real-time PCR and western blot, respectively. Edelfosine significantly reduced the GRA1 (P < 0.01) and MIC3 (P < 0.01) mRNA and protein expressions in 24 h following the cell infection and at the same time of cell infection groups. In vivo study showed that the edelfosine significantly reduced the GRA1 expression in eye, and MIC3 expression in brain and liver. Moreover, the edelfosine-treated infected mice had significant higher survival rate compared with uninfected mice. The reducing effect of edelfosine on GRA1 and MIC3 mRNA and protein levels 24 h following the cell infection was more than treatment at the same time of cell infection group. Moreover, the effect of edelfosine on GRA1 and MIC3 expression in animal tissues was variable. These data showed that the edelfosine may decrease the T. gondii excretory/secretory antigens through inhibition of PI-PLC.
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33
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Albuquerque-Wendt A, Jacot D, Dos Santos Pacheco N, Seegers C, Zarnovican P, Buettner FFR, Bakker H, Soldati-Favre D, Routier FH. C-Mannosylation of Toxoplasma gondii proteins promotes attachment to host cells and parasite virulence. J Biol Chem 2020; 295:1066-1076. [PMID: 31862733 DOI: 10.1074/jbc.ra119.010590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 12/17/2019] [Indexed: 01/21/2023] Open
Abstract
C-Mannosylation is a common modification of thrombospondin type 1 repeats present in metazoans and recently identified also in apicomplexan parasites. This glycosylation is mediated by enzymes of the DPY19 family that transfer α-mannoses to tryptophan residues in the sequence WX 2WX 2C, which is part of the structurally essential tryptophan ladder. Here, deletion of the dpy19 gene in the parasite Toxoplasma gondii abolished C-mannosyltransferase activity and reduced levels of the micronemal protein MIC2. The loss of C-mannosyltransferase activity was associated with weakened parasite adhesion to host cells and with reduced parasite motility, host cell invasion, and parasite egress. Interestingly, the C-mannosyltransferase-deficient Δdpy19 parasites were strongly attenuated in virulence and induced protective immunity in mice. This parasite attenuation could not simply be explained by the decreased MIC2 level and strongly suggests that absence of C-mannosyltransferase activity leads to an insufficient level of additional proteins. In summary, our results indicate that T. gondii C-mannosyltransferase DPY19 is not essential for parasite survival, but is important for adhesion, motility, and virulence.
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Affiliation(s)
| | - Damien Jacot
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1206 Geneva, Switzerland
| | | | - Carla Seegers
- Department of Clinical Biochemistry OE4340, Hannover Medical School, 30625 Hannover, Germany
| | - Patricia Zarnovican
- Department of Clinical Biochemistry OE4340, Hannover Medical School, 30625 Hannover, Germany
| | - Falk F R Buettner
- Department of Clinical Biochemistry OE4340, Hannover Medical School, 30625 Hannover, Germany
| | - Hans Bakker
- Department of Clinical Biochemistry OE4340, Hannover Medical School, 30625 Hannover, Germany
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1206 Geneva, Switzerland
| | - Françoise H Routier
- Department of Clinical Biochemistry OE4340, Hannover Medical School, 30625 Hannover, Germany
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34
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Albuquerque-Wendt A, Jacot D, Dos Santos Pacheco N, Seegers C, Zarnovican P, Buettner FF, Bakker H, Soldati-Favre D, Routier FH. C-Mannosylation of Toxoplasma gondii proteins promotes attachment to host cells and parasite virulence. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49916-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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35
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Localization and enzyme kinetics of aminopeptidase N3 from Toxoplasma gondii. Parasitol Res 2019; 119:357-364. [PMID: 31836922 DOI: 10.1007/s00436-019-06512-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 10/15/2019] [Indexed: 10/25/2022]
Abstract
Aminopeptidase N is an important metalloenzyme from the M1 zinc metallopeptidase family, which is present in numerous apicomplexan parasites, including Plasmodium, Eimeria, and Cryptosporidium. Aminopeptidase N is a potential drug target, and hence, its properties have been widely investigated. In the current study, the cellular localization and enzyme characteristics of Toxoplasma gondii aminopeptidase N3 (TgAPN3) were evaluated in vitro. Cellular localization analysis revealed that TgAPN3 and GRA protein were co-located in the organelle and parasitophorous vacuole of T. gondii. The secretion assay showed that TgAPN3 could be co-secreted from the tachyzoites with GRA protein. A functional recombinant Toxoplasma aminopeptidase N3 (rTgAPN3) was produced in Escherichia coli. The enzyme activity was first determined using a fluorogenic H-Ala-MCA substrate. Some activity of rTgAPN3 was observed between pH 3.0 and 8.0, with a peak at pH 7.0. The activity was significantly enhanced in the presence of Co2+ ions. Substrate specificity of rTgAPN3 was then evaluated. The enzyme showed a preference for substrates containing N-terminal Ala residues, followed by Tyr and Cys. The rTgAPN3 activity was significantly inhibited by bestatin and phebestatin. In general, TgAPN3 was a structurally conserved member of the M1 family, although it also displayed unique biochemical characteristics. These results lay the foundation for a functional study of TgAPN3 and constitute its putative identification as a drug target.
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36
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Abstract
Apicomplexans, including species of Eimeria, pose a real threat to the health and wellbeing of animals and humans. Eimeria parasites do not infect humans but cause an important economic impact on livestock, in particular on the poultry industry. Despite its high prevalence and financial costs, little is known about the cell biology of these 'cosmopolitan' parasites found all over the world. In this review, we discuss different aspects of the life cycle and stages of Eimeria species, focusing on cellular structures and organelles typical of the coccidian family as well as genus-specific features, complementing some 'unknowns' with what is described in the closely related coccidian Toxoplasma gondii.
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37
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Bantuchai S, Nozaki M, Thongkukiatkul A, Lorsuwannarat N, Tachibana M, Baba M, Matsuoka K, Tsuboi T, Torii M, Ishino T. Rhoptry neck protein 11 has crucial roles during malaria parasite sporozoite invasion of salivary glands and hepatocytes. Int J Parasitol 2019; 49:725-735. [DOI: 10.1016/j.ijpara.2019.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 03/29/2019] [Accepted: 05/03/2019] [Indexed: 12/01/2022]
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38
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Bullen HE, Bisio H, Soldati-Favre D. The triumvirate of signaling molecules controlling Toxoplasma microneme exocytosis: Cyclic GMP, calcium, and phosphatidic acid. PLoS Pathog 2019; 15:e1007670. [PMID: 31121005 PMCID: PMC6532924 DOI: 10.1371/journal.ppat.1007670] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
To elicit effective invasion and egress from infected cells, obligate intracellular parasites of the phylum Apicomplexa rely on the timely and spatially controlled exocytosis of specialized secretory organelles termed the micronemes. The effector molecules and signaling events underpinning this process are intricate; however, recent advances within the field of Toxoplasma gondii research have facilitated a broader understanding as well as a more integrated view of this complex cascade of events and have unraveled the importance of phosphatidic acid (PA) as a lipid mediator at multiple steps in this process.
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Affiliation(s)
- Hayley E. Bullen
- Burnet Institute, Melbourne, Victoria, Australia
- * E-mail: (HEB); (DS-F)
| | - Hugo Bisio
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland
- * E-mail: (HEB); (DS-F)
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39
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Wallbank BA, Dominicus CS, Broncel M, Legrave N, Kelly G, MacRae JI, Staines HM, Treeck M. Characterisation of the Toxoplasma gondii tyrosine transporter and its phosphorylation by the calcium-dependent protein kinase 3. Mol Microbiol 2019; 111:1167-1181. [PMID: 30402958 PMCID: PMC6488386 DOI: 10.1111/mmi.14156] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2018] [Indexed: 12/21/2022]
Abstract
Toxoplasma gondii parasites rapidly exit their host cell when exposed to calcium ionophores. Calcium-dependent protein kinase 3 (TgCDPK3) was previously identified as a key mediator in this process, as TgCDPK3 knockout (∆cdpk3) parasites fail to egress in a timely manner. Phosphoproteomic analysis comparing WT with ∆cdpk3 parasites revealed changes in the TgCDPK3-dependent phosphoproteome that included proteins important for regulating motility, but also metabolic enzymes, indicating that TgCDPK3 controls processes beyond egress. Here we have investigated a predicted direct target of TgCDPK3, ApiAT5-3, a putative transporter of the major facilitator superfamily, and show that it is rapidly phosphorylated at serine 56 after induction of calcium signalling. Conditional knockout of apiAT5-3 results in transcriptional upregulation of most ribosomal subunits, but no alternative transporters, and subsequent parasite death. Mutating the S56 to a non-phosphorylatable alanine leads to a fitness cost, suggesting that phosphorylation of this residue is beneficial, albeit not essential, for tyrosine import. Using a combination of metabolomics and heterologous expression, we confirmed a primary role in tyrosine import for ApiAT5-3. However, no significant differences in tyrosine import could be detected in phosphorylation site mutants showing that if tyrosine transport is affected by S56 phosphorylation, its regulatory role is subtle.
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Affiliation(s)
- Bethan A. Wallbank
- Signalling in Apicomplexan Parasites LaboratoryThe Francis Crick InstituteLondonUK
| | - Caia S. Dominicus
- Signalling in Apicomplexan Parasites LaboratoryThe Francis Crick InstituteLondonUK
| | - Malgorzata Broncel
- Signalling in Apicomplexan Parasites LaboratoryThe Francis Crick InstituteLondonUK
| | - Nathalie Legrave
- Metabolomics Science Technology PlatformThe Francis Crick InstituteLondonUK
| | - Gavin Kelly
- Bioinformatics and Biostatistics STPFrancis Crick Institute1 Midland RoadLondon NW1 1ATUK
| | - James I. MacRae
- Metabolomics Science Technology PlatformThe Francis Crick InstituteLondonUK
| | - Henry M. Staines
- Institute of Infection and ImmunitySt George’s, University of LondonLondonUK
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites LaboratoryThe Francis Crick InstituteLondonUK
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40
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Yang L, Uboldi AD, Seizova S, Wilde ML, Coffey MJ, Katris NJ, Yamaryo-Botté Y, Kocan M, Bathgate RAD, Stewart RJ, McConville MJ, Thompson PE, Botté CY, Tonkin CJ. An apically located hybrid guanylate cyclase-ATPase is critical for the initiation of Ca 2+ signaling and motility in Toxoplasma gondii. J Biol Chem 2019; 294:8959-8972. [PMID: 30992368 DOI: 10.1074/jbc.ra118.005491] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 04/12/2019] [Indexed: 11/06/2022] Open
Abstract
Protozoan parasites of the phylum Apicomplexa actively move through tissue to initiate and perpetuate infection. The regulation of parasite motility relies on cyclic nucleotide-dependent kinases, but how these kinases are activated remains unknown. Here, using an array of biochemical and cell biology approaches, we show that the apicomplexan parasite Toxoplasma gondii expresses a large guanylate cyclase (TgGC) protein, which contains several upstream ATPase transporter-like domains. We show that TgGC has a dynamic localization, being concentrated at the apical tip in extracellular parasites, which then relocates to a more cytosolic distribution during intracellular replication. Conditional TgGC knockdown revealed that this protein is essential for acute-stage tachyzoite growth, as TgGC-deficient parasites were defective in motility, host cell attachment, invasion, and subsequent host cell egress. We show that TgGC is critical for a rapid rise in cytosolic [Ca2+] and for secretion of microneme organelles upon stimulation with a cGMP agonist, but these deficiencies can be bypassed by direct activation of signaling by a Ca2+ ionophore. Furthermore, we found that TgGC is required for transducing changes in extracellular pH and [K+] to activate cytosolic [Ca2+] flux. Together, the results of our work implicate TgGC as a putative signal transducer that activates Ca2+ signaling and motility in Toxoplasma.
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Affiliation(s)
- Luning Yang
- From the The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.,School of Medicine, Tsinghua University, Beijing, China 100006
| | - Alessandro D Uboldi
- From the The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Simona Seizova
- From the The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Mary-Louise Wilde
- From the The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Michael J Coffey
- From the The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Nicholas J Katris
- ApicoLipid Team, Institute of Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Yoshiki Yamaryo-Botté
- ApicoLipid Team, Institute of Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Martina Kocan
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Ross A D Bathgate
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia.,Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3052, Australia, and
| | - Rebecca J Stewart
- From the The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3052, Australia, and
| | - Philip E Thompson
- Monash Institute of Pharmaceutical Science, Monash University, Parkville, Victoria 3052, Australia
| | - Cyrille Y Botté
- ApicoLipid Team, Institute of Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Christopher J Tonkin
- From the The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria 3052, Australia, .,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
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Bumped kinase inhibitor 1369 is effective against Cystoisospora suis in vivo and in vitro. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2019; 10:9-19. [PMID: 30959327 PMCID: PMC6453670 DOI: 10.1016/j.ijpddr.2019.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 03/25/2019] [Accepted: 03/28/2019] [Indexed: 12/22/2022]
Abstract
Cystoisosporosis is a leading diarrheal disease in suckling piglets. With the confirmation of resistance against the only available drug toltrazuril, there is a substantial need for novel therapeutics to combat the infection and its negative effects on animal health. In closely related apicomplexan species, bumped kinase inhibitors (BKIs) targeting calcium-dependent protein kinase 1 (CDPK1) were shown to be effective in inhibiting host-cell invasion and parasite growth. Therefore, the gene coding for Cystoisospora suis CDPK1 (CsCDPK1) was identified and cloned to investigate activity and thermal stabilization of the recombinant CsCDPK1 enzyme by BKI 1369. In this comprehensive study, the efficacy, safety and pharmacokinetics of BKI 1369 in piglets experimentally infected with Cystoisospora suis (toltrazuril-sensitive, Wien-I and toltrazuril-resistant, Holland-I strains) were determined in vivo and in vitro using an established animal infection model and cell culture, respectively. BKI 1369 inhibited merozoite proliferation in intestinal porcine epithelial cells-1 (IPEC-1) by at least 50% at a concentration of 40 nM, and proliferation was almost completely inhibited (>95%) at 200 nM. Nonetheless, exposure of infected cultures to 200 nM BKI 1369 for five days did not induce structural alterations in surviving merozoites as confirmed by transmission electron microscopy. Five-day treatment with BKI 1369 (10 mg/kg BW twice a day) effectively suppressed oocyst excretion and diarrhea and improved body weight gains in treated piglets without obvious side effects for both toltrazuril-sensitive, Wien-I and resistant, Holland-I C. suis strains. The plasma concentration of BKI 1369 in piglets increased to 11.7 μM during treatment, suggesting constant drug accumulation and exposure of parasites to the drug. Therefore, oral applications of BKI 1369 could potentially be a therapeutic alternative against porcine cystoisosporosis. For use in pigs, future studies on BKI 1369 should be directed towards ease of drug handling and minimizing treatment frequencies. Oral application of BKI 1369 effectively reduced oocyst excretion and diarrhea in Cystoisospora suis infected piglets. 200 nM of BKI 1369 almost completely suppressed parasite proliferation in vitro. IC50 and IC95 concentrations of BKI 1369 did not induce morphological alterations in in vitro cultured merozoites. Cystoisosporasuis CDPK1, the putative target of BKI 1369, has glycine as gatekeeper residue.
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Secretory Microneme Proteins Induce T-Cell Recall Responses in Mice Chronically Infected with Toxoplasma gondii. mSphere 2019; 4:4/1/e00711-18. [PMID: 30814319 PMCID: PMC6393730 DOI: 10.1128/msphere.00711-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Current diagnosis of toxoplasmosis relies almost exclusively on antibody detection, and while detection of IgG provides a useful estimate of prior infection, it does not alone indicate immune status. In contrast, detection of IFN-γ responses to T. gondii antigens has been used to monitor immune responsiveness in HIV-infected patients, thus providing valuable predictions about the potential for disease reactivation. However, specific T. gondii antigens that can be used in assays to detect cellular immunity remain largely undefined. In this study, we examined the diagnostic potential of microneme antigens of T. gondii using IFN-γ detection assays. Our findings demonstrate that MIC antigens (MIC1, MIC3, MIC4, and MIC6) elicit IFN-γ responses from memory T cells in chronically infected mice. Monitoring IFN-γ production by T cells stimulated with MIC antigens provided high sensitivity and specificity for detection of T. gondii infection in mice. Taken together, these studies suggest that microneme antigens might be useful as an adjunct to serological testing to monitor immune status during infection. Microneme (MIC) proteins play important roles in the recognition, adhesion, and invasion of host cells by Toxoplasma gondii. Previous studies have shown that MIC proteins are highly immunogenic in the mouse and recognized by human serum antibodies. Here we report that T. gondii antigens MIC1, MIC3, MIC4, and MIC6 were capable of inducing memory responses leading to production of gamma interferon (IFN-γ) by T cells from T. gondii-infected mice. Production of IFN-γ was demonstrated using enzyme-linked immunosorbent spot (ELISPOT) assay and also intracellular cytokine staining. All four MIC antigens displayed very high sensitivity (100%) and specificity (86 to 100%) for detecting chronic infection. Interestingly, IFN-γ was produced by both CD4+ and CD8+ T cells in BALB/c mice but primarily by CD4+ T cells in C57BL/6 mice. Phenotypic characterization of IFN-γ-producing CD4+ and CD8+ T cells in BALB/c mice and CD4+ T cells in C57BL/6 mice revealed effector memory T cells (CD44hi CD62Llo) as the predominant cells that contributed to IFN-γ production in response to MIC antigens. Effector memory responses were seen in mice of different major histocompatibility complex class II (MHC-II) haplotypes, suggesting that MIC antigens contain epitopes that are broadly recognized. IMPORTANCE Current diagnosis of toxoplasmosis relies almost exclusively on antibody detection, and while detection of IgG provides a useful estimate of prior infection, it does not alone indicate immune status. In contrast, detection of IFN-γ responses to T. gondii antigens has been used to monitor immune responsiveness in HIV-infected patients, thus providing valuable predictions about the potential for disease reactivation. However, specific T. gondii antigens that can be used in assays to detect cellular immunity remain largely undefined. In this study, we examined the diagnostic potential of microneme antigens of T. gondii using IFN-γ detection assays. Our findings demonstrate that MIC antigens (MIC1, MIC3, MIC4, and MIC6) elicit IFN-γ responses from memory T cells in chronically infected mice. Monitoring IFN-γ production by T cells stimulated with MIC antigens provided high sensitivity and specificity for detection of T. gondii infection in mice. Taken together, these studies suggest that microneme antigens might be useful as an adjunct to serological testing to monitor immune status during infection.
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Bandini G, Leon DR, Hoppe CM, Zhang Y, Agop-Nersesian C, Shears MJ, Mahal LK, Routier FH, Costello CE, Samuelson J. O-Fucosylation of thrombospondin-like repeats is required for processing of microneme protein 2 and for efficient host cell invasion by Toxoplasma gondii tachyzoites. J Biol Chem 2018; 294:1967-1983. [PMID: 30538131 DOI: 10.1074/jbc.ra118.005179] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 12/10/2018] [Indexed: 11/06/2022] Open
Abstract
Toxoplasma gondii is an intracellular parasite that causes disseminated infections that can produce neurological damage in fetuses and immunocompromised individuals. Microneme protein 2 (MIC2), a member of the thrombospondin-related anonymous protein (TRAP) family, is a secreted protein important for T. gondii motility, host cell attachment, invasion, and egress. MIC2 contains six thrombospondin type I repeats (TSRs) that are modified by C-mannose and O-fucose in Plasmodium spp. and mammals. Here, using MS analysis, we found that the four TSRs in T. gondii MIC2 with protein O-fucosyltransferase 2 (POFUT2) acceptor sites are modified by a dHexHex disaccharide, whereas Trp residues within three TSRs are also modified with C-mannose. Disruption of genes encoding either POFUT2 or the putative GDP-fucose transporter (NST2) resulted in loss of MIC2 O-fucosylation, as detected by an antibody against the GlcFuc disaccharide, and in markedly reduced cellular levels of MIC2. Furthermore, in 10-15% of the Δpofut2 or Δnst2 vacuoles, MIC2 accumulated earlier in the secretory pathway rather than localizing to micronemes. Dissemination of tachyzoites in human foreskin fibroblasts was reduced for these knockouts, which both exhibited defects in attachment to and invasion of host cells comparable with the Δmic2 phenotype. These results, indicating that O-fucosylation of TSRs is required for efficient processing of MIC2 and for normal parasite invasion, are consistent with the recent demonstration that Plasmodium falciparum Δpofut2 strain has decreased virulence and also support a conserved role for this glycosylation pathway in quality control of TSR-containing proteins in eukaryotes.
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Affiliation(s)
- Giulia Bandini
- From the Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts 02118
| | - Deborah R Leon
- the Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Carolin M Hoppe
- the Department of Clinical Biochemistry OE4340, Hannover Medical School, 30625 Hannover, Germany
| | - Yue Zhang
- the Department of Chemistry, Biomedical Chemistry Institute, New York University, New York, New York 10003, and
| | - Carolina Agop-Nersesian
- From the Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts 02118
| | - Melanie J Shears
- the Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Lara K Mahal
- the Department of Chemistry, Biomedical Chemistry Institute, New York University, New York, New York 10003, and
| | - Françoise H Routier
- the Department of Clinical Biochemistry OE4340, Hannover Medical School, 30625 Hannover, Germany
| | - Catherine E Costello
- the Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - John Samuelson
- From the Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts 02118,
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44
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Arredondo SA, Swearingen KE, Martinson T, Steel R, Dankwa DA, Harupa A, Camargo N, Betz W, Vigdorovich V, Oliver BG, Kangwanrangsan N, Ishino T, Sather N, Mikolajczak S, Vaughan AM, Torii M, Moritz RL, Kappe SHI. The Micronemal Plasmodium Proteins P36 and P52 Act in Concert to Establish the Replication-Permissive Compartment Within Infected Hepatocytes. Front Cell Infect Microbiol 2018; 8:413. [PMID: 30547015 PMCID: PMC6280682 DOI: 10.3389/fcimb.2018.00413] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/08/2018] [Indexed: 12/15/2022] Open
Abstract
Within the liver, Plasmodium sporozoites traverse cells searching for a "suitable" hepatocyte, invading these cells through a process that results in the formation of a parasitophorous vacuole (PV), within which the parasite undergoes intracellular replication as a liver stage. It was previously established that two members of the Plasmodium s48/45 protein family, P36 and P52, are essential for productive invasion of host hepatocytes by sporozoites as their simultaneous deletion results in growth-arrested parasites that lack a PV. Recent studies point toward a pathway of entry possibly involving the interaction of P36 with hepatocyte receptors EphA2, CD81, and SR-B1. However, the relationship between P36 and P52 during sporozoite invasion remains unknown. Here we show that parasites with a single P52 or P36 gene deletion each lack a PV after hepatocyte invasion, thereby pheno-copying the lack of a PV observed for the P52/P36 dual gene deletion parasite line. This indicates that both proteins are equally important in the establishment of a PV and act in the same pathway. We created a Plasmodium yoelii P36mCherry tagged parasite line that allowed us to visualize the subcellular localization of P36 and found that it partially co-localizes with P52 in the sporozoite secretory microneme organelles. Furthermore, through co-immunoprecipitation studies in vivo, we determined that P36 and P52 form a protein complex in sporozoites, indicating a concerted function for both proteins within the PV formation pathway. However, upon sporozoite stimulation, only P36 was released as a secreted protein while P52 was not. Our results support a model in which the putatively glycosylphosphatidylinositol (GPI)-anchored P52 may serve as a scaffold to facilitate the interaction of secreted P36 with the host cell during sporozoite invasion of hepatocytes.
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Affiliation(s)
- Silvia A. Arredondo
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | | | - Thomas Martinson
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Ryan Steel
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Dorender A. Dankwa
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Anke Harupa
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Nelly Camargo
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - William Betz
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Vladimir Vigdorovich
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Brian G. Oliver
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Niwat Kangwanrangsan
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Tomoko Ishino
- Department of Molecular Parasitology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Japan
| | - Noah Sather
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Sebastian Mikolajczak
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Ashley M. Vaughan
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Motomi Torii
- Department of Molecular Parasitology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Japan
| | | | - Stefan H. I. Kappe
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, United States
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Brown KM, Sibley LD. Essential cGMP Signaling in Toxoplasma Is Initiated by a Hybrid P-Type ATPase-Guanylate Cyclase. Cell Host Microbe 2018; 24:804-816.e6. [PMID: 30449726 DOI: 10.1016/j.chom.2018.10.015] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 08/30/2018] [Accepted: 10/01/2018] [Indexed: 11/28/2022]
Abstract
Apicomplexan parasites rely on cyclic nucleotide-dependent kinases for host cell infection, yet the mechanisms that control their activation remain unknown. Here we show that an apically localized guanylate cyclase (GC) controls microneme secretion and lytic growth in the model apicomplexan Toxoplasma gondii. Cell-permeable cGMP reversed the block in microneme secretion seen in a knockdown of TgGC, linking its function to production of cGMP. TgGC possesses an N-terminal P-type ATPase domain fused to a C-terminal heterodimeric guanylate cyclase domain, an architecture found only in Apicomplexa and related protists. Complementation with a panel of mutants revealed a critical requirement for the P-type ATPase domain for maximum GC function. We further demonstrate that knockdown of TgGC in vivo protects mice from lethal infection by blocking parasite expansion and dissemination. Collectively, this work demonstrates that cGMP-mediated signaling in Toxoplasma relies on a multi-domain architecture, which may serve a conserved role in related parasites.
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Affiliation(s)
- Kevin M Brown
- Department of Molecular Microbiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA.
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46
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Klug D, Kehrer J, Frischknecht F, Singer M. A synthetic promoter for multi-stage expression to probe complementary functions of Plasmodium adhesins. J Cell Sci 2018; 131:jcs.210971. [PMID: 30237220 DOI: 10.1242/jcs.210971] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 09/10/2018] [Indexed: 11/20/2022] Open
Abstract
Gene expression of malaria parasites is mediated by the apicomplexan Apetala2 (ApiAP2) transcription factor family. Different ApiAP2s control gene expression at distinct stages in the complex life cycle of the parasite, ensuring timely expression of stage-specific genes. ApiAP2s recognize short cis-regulatory elements that are enriched in the upstream/promoter region of their target genes. This should, in principle, allow the generation of 'synthetic' promoters that drive gene expression at desired stages of the Plasmodium life cycle. Here we test this concept by combining cis-regulatory elements of two genes expressed successively within the mosquito part of the life cycle. Our tailored 'synthetic' promoters, named Spooki 1.0 and Spooki 2.0, activate gene expression in early and late mosquito stages, as shown by the expression of a fluorescent reporter. We used these promoters to address the specific functionality of two related adhesins that are exclusively expressed either during the early or late mosquito stage. By modifying the expression profile of both adhesins in absence of their counterpart we were able to test for complementary functions in gliding and invasion. We discuss the possible advantages and drawbacks of our approach.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Dennis Klug
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Jessica Kehrer
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Mirko Singer
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
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47
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Abstract
Apicomplexan protozoan parasites, such as those causing malaria and toxoplasmosis, must invade the cells of their hosts in order to establish a pathogenic infection. Timely release of proteins from a series of apical organelles is required for invasion. Neither the vesicular fusion events that underlie secretion nor the observed reliance of the various processes on changes in intracellular calcium concentrations is completely understood. We identified a group of three proteins with strong homology to the calcium-sensing ferlin family, which are known to be involved in protein secretion in other organisms. Surprisingly, decreasing the amounts of one of these proteins (TgFER2) did not have any effect on the typically calcium-dependent steps in invasion. Instead, TgFER2 was essential for the release of proteins from organelles called rhoptries. These data provide a tantalizing first look at the mechanisms controlling the very poorly understood process of rhoptry secretion, which is essential for the parasite’s infection cycle. Invasion of host cells by apicomplexan parasites such as Toxoplasma gondii is critical for their infectivity and pathogenesis. In Toxoplasma, secretion of essential egress, motility, and invasion-related proteins from microneme organelles is regulated by oscillations of intracellular Ca2+. Later stages of invasion are considered Ca2+ independent, including the secretion of proteins required for host cell entry and remodeling from the parasite’s rhoptries. We identified a family of three Toxoplasma proteins with homology to the ferlin family of double C2 domain-containing Ca2+ sensors. In humans and model organisms, such Ca2+ sensors orchestrate Ca2+-dependent exocytic membrane fusion with the plasma membrane. Here we focus on one ferlin that is conserved across the Apicomplexa, T. gondii FER2 (TgFER2). Unexpectedly, conditionally TgFER2-depleted parasites secreted their micronemes normally and were completely motile. However, these parasites were unable to invade host cells and were therefore not viable. Knockdown of TgFER2 prevented rhoptry secretion, and these parasites failed to form the moving junction at the parasite-host interface necessary for host cell invasion. Collectively, these data demonstrate the requirement of TgFER2 for rhoptry secretion in Toxoplasma tachyzoites and suggest a possible Ca2+ dependence of rhoptry secretion. These findings provide the first mechanistic insights into this critical yet poorly understood aspect of apicomplexan host cell invasion.
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48
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Caldas LA, de Souza W. A Window to Toxoplasma gondii Egress. Pathogens 2018; 7:pathogens7030069. [PMID: 30110938 PMCID: PMC6161258 DOI: 10.3390/pathogens7030069] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/09/2018] [Accepted: 08/10/2018] [Indexed: 11/23/2022] Open
Abstract
The Toxoplasma gondii cellular cycle has been widely studied in many lifecycle stages; however, the egress event still is poorly understood even though different types of molecules were shown to be involved. Assuming that there is no purpose or intentionality in biological phenomena, there is no such question as “Why does the parasite leaves the host cell”, but “Under what conditions and how?”. In this review we aimed to summarize current knowledge concerning T. gondii egress physiology (signalling pathways), structures, and route.
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Affiliation(s)
- Lucio Ayres Caldas
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil.
- Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Cidade Universitária, Rio de Janeiro, RJ 21941-902, Brazil.
| | - Wanderley de Souza
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil.
- Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Cidade Universitária, Rio de Janeiro, RJ 21941-902, Brazil.
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49
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Hortua Triana MA, Márquez-Nogueras KM, Vella SA, Moreno SNJ. Calcium signaling and the lytic cycle of the Apicomplexan parasite Toxoplasma gondii. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1846-1856. [PMID: 30992126 DOI: 10.1016/j.bbamcr.2018.08.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 01/24/2023]
Abstract
Toxoplasma gondii has a complex life cycle involving different hosts and is dependent on fast responses, as the parasite reacts to changing environmental conditions. T. gondii causes disease by lysing the host cells that it infects and it does this by reiterating its lytic cycle, which consists of host cell invasion, replication inside the host cell, and egress causing host cell lysis. Calcium ion (Ca2+) signaling triggers activation of molecules involved in the stimulation and enhancement of each step of the parasite lytic cycle. Ca2+ signaling is essential for the cellular and developmental changes that support T. gondii parasitism. The characterization of the molecular players and pathways directly activated by Ca2+ signaling in Toxoplasma is sketchy and incomplete. The evolutionary distance between Toxoplasma and other eukaryotic model systems makes the comparison sometimes not informative. The advent of new genomic information and new genetic tools applicable for studying Toxoplasma biology is rapidly changing this scenario. The Toxoplasma genome reveals the presence of many genes potentially involved in Ca2+ signaling, even though the role of most of them is not known. The use of Genetically Encoded Calcium Indicators (GECIs) has allowed studies on the role of novel calcium-related proteins on egress, an essential step for the virulence and dissemination of Toxoplasma. In addition, the discovery of new Ca2+ players is generating novel targets for drugs, vaccines, and diagnostic tools and a better understanding of the biology of these parasites.
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Affiliation(s)
| | | | - Stephen A Vella
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Silvia N J Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA; Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA.
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50
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Darvill N, Dubois DJ, Rouse SL, Hammoudi PM, Blake T, Benjamin S, Liu B, Soldati-Favre D, Matthews S. Structural Basis of Phosphatidic Acid Sensing by APH in Apicomplexan Parasites. Structure 2018; 26:1059-1071.e6. [PMID: 29910186 PMCID: PMC6084407 DOI: 10.1016/j.str.2018.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 03/26/2018] [Accepted: 05/08/2018] [Indexed: 10/29/2022]
Abstract
Plasmodium falciparum and Toxoplasma gondii are obligate intracellular parasites that belong to the phylum of Apicomplexa and cause major human diseases. Their access to an intracellular lifestyle is reliant on the coordinated release of proteins from the specialized apical organelles called micronemes and rhoptries. A specific phosphatidic acid effector, the acylated pleckstrin homology domain-containing protein (APH) plays a central role in microneme exocytosis and thus is essential for motility, cell entry, and egress. TgAPH is acylated on the surface of the micronemes and recruited to phosphatidic acid (PA)-enriched membranes. Here, we dissect the atomic details of APH PA-sensing hub and its functional interaction with phospholipid membranes. We unravel the key determinant of PA recognition for the first time and show that APH inserts into and clusters multiple phosphate head-groups at the bilayer binding surface.
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Affiliation(s)
- Nick Darvill
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - David J Dubois
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, 1 Rue Michel-Servet, 1211 Geneva, Switzerland
| | - Sarah L Rouse
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - Pierre-Mehdi Hammoudi
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, 1 Rue Michel-Servet, 1211 Geneva, Switzerland
| | - Tom Blake
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - Stefi Benjamin
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - Bing Liu
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK; BioBank, First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Dominique Soldati-Favre
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, 1 Rue Michel-Servet, 1211 Geneva, Switzerland.
| | - Steve Matthews
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK; BioBank, First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, 710049, P. R. China.
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