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Hortua Triana MA, Márquez-Nogueras KM, Fazli MS, Quinn S, Moreno SNJ. Regulation of calcium entry by cyclic GMP signaling in Toxoplasma gondii. J Biol Chem 2024; 300:105771. [PMID: 38382669 PMCID: PMC10959671 DOI: 10.1016/j.jbc.2024.105771] [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: 08/01/2023] [Revised: 01/09/2024] [Accepted: 01/28/2024] [Indexed: 02/23/2024] Open
Abstract
Ca2+ signaling impacts almost every aspect of cellular life. Ca2+ signals are generated through the opening of ion channels that permit the flow of Ca2+ down an electrochemical gradient. Cytosolic Ca2+ fluctuations can be generated through Ca2+ entry from the extracellular milieu or release from intracellular stores. In Toxoplasma gondii, Ca2+ ions play critical roles in several essential functions for the parasite, like invasion of host cells, motility, and egress. Plasma membrane Ca2+ entry in T. gondii was previously shown to be activated by cytosolic calcium and inhibited by the voltage-operated Ca2+ channel blocker nifedipine. However, Ca2+ entry in T. gondii did not show the classical characteristics of store regulation. In this work, we characterized the mechanism by which cytosolic Ca2+ regulates plasma membrane Ca2+ entry in extracellular T. gondii tachyzoites loaded with the Ca2+ indicator Fura-2. We compared the inhibition by nifedipine with the effect of the broad spectrum TRP channel inhibitor, anthranilic acid or ACA, and we find that both inhibitors act on different Ca2+ entry activities. We demonstrate, using pharmacological and genetic tools, that an intracellular signaling pathway engaging cyclic GMP, protein kinase G, Ca2+, and the phosphatidyl inositol phospholipase C affects Ca2+ entry and we present a model for crosstalk between cyclic GMP and cytosolic Ca2+ for the activation of T. gondii's lytic cycle traits.
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Affiliation(s)
- Miryam A Hortua Triana
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | | | | | - Shannon Quinn
- Department of Computer Science, University of Georgia, Athens, Georgia, USA
| | - Silvia N J Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA; Department of Cellular Biology, University of Georgia, Athens, Georgia, USA.
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2
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Chan AW, Broncel M, Yifrach E, Haseley NR, Chakladar S, Andree E, Herneisen AL, Shortt E, Treeck M, Lourido S. Analysis of CDPK1 targets identifies a trafficking adaptor complex that regulates microneme exocytosis in Toxoplasma. eLife 2023; 12:RP85654. [PMID: 37933960 PMCID: PMC10629828 DOI: 10.7554/elife.85654] [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] [Indexed: 11/08/2023] Open
Abstract
Apicomplexan parasites use Ca2+-regulated exocytosis to secrete essential virulence factors from specialized organelles called micronemes. Ca2+-dependent protein kinases (CDPKs) are required for microneme exocytosis; however, the molecular events that regulate trafficking and fusion of micronemes with the plasma membrane remain unresolved. Here, we combine sub-minute resolution phosphoproteomics and bio-orthogonal labeling of kinase substrates in Toxoplasma gondii to identify 163 proteins phosphorylated in a CDPK1-dependent manner. In addition to known regulators of secretion, we identify uncharacterized targets with predicted functions across signaling, gene expression, trafficking, metabolism, and ion homeostasis. One of the CDPK1 targets is a putative HOOK activating adaptor. In other eukaryotes, HOOK homologs form the FHF complex with FTS and FHIP to activate dynein-mediated trafficking of endosomes along microtubules. We show the FHF complex is partially conserved in T. gondii, consisting of HOOK, an FTS homolog, and two parasite-specific proteins (TGGT1_306920 and TGGT1_316650). CDPK1 kinase activity and HOOK are required for the rapid apical trafficking of micronemes as parasites initiate motility. Moreover, parasites lacking HOOK or FTS display impaired microneme protein secretion, leading to a block in the invasion of host cells. Taken together, our work provides a comprehensive catalog of CDPK1 targets and reveals how vesicular trafficking has been tuned to support a parasitic lifestyle.
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Affiliation(s)
- Alex W Chan
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Malgorzata Broncel
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Eden Yifrach
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Nicole R Haseley
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | | | - Elena Andree
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Alice L Herneisen
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Emily Shortt
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Moritz Treeck
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
| | - Sebastian Lourido
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Biology Department, Massachusetts Institute of TechnologyCambridgeUnited States
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3
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Chan AW, Broncel M, Yifrach E, Haseley N, Chakladar S, Andree E, Herneisen AL, Shortt E, Treeck M, Lourido S. Analysis of CDPK1 targets identifies a trafficking adaptor complex that regulates microneme exocytosis in Toxoplasma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.11.523553. [PMID: 36712004 PMCID: PMC9882037 DOI: 10.1101/2023.01.11.523553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Apicomplexan parasites use Ca2+-regulated exocytosis to secrete essential virulence factors from specialized organelles called micronemes. Ca2+-dependent protein kinases (CDPKs) are required for microneme exocytosis; however, the molecular events that regulate trafficking and fusion of micronemes with the plasma membrane remain unresolved. Here, we combine sub-minute resolution phosphoproteomics and bio-orthogonal labeling of kinase substrates in Toxoplasma gondii to identify 163 proteins phosphorylated in a CDPK1-dependent manner. In addition to known regulators of secretion, we identify uncharacterized targets with predicted functions across signaling, gene expression, trafficking, metabolism, and ion homeostasis. One of the CDPK1 targets is a putative HOOK activating adaptor. In other eukaryotes, HOOK homologs form the FHF complex with FTS and FHIP to activate dynein-mediated trafficking of endosomes along microtubules. We show the FHF complex is partially conserved in T. gondii, consisting of HOOK, an FTS homolog, and two parasite-specific proteins (TGGT1_306920 and TGGT1_316650). CDPK1 kinase activity and HOOK are required for the rapid apical trafficking of micronemes as parasites initiate motility. Moreover, parasites lacking HOOK or FTS display impaired microneme protein secretion, leading to a block in the invasion of host cells. Taken together, our work provides a comprehensive catalog of CDPK1 targets and reveals how vesicular trafficking has been tuned to support a parasitic lifestyle.
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Affiliation(s)
- Alex W Chan
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Malgorzata Broncel
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, UK
| | - Eden Yifrach
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Nicole Haseley
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | | | - Elena Andree
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Alice L Herneisen
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Emily Shortt
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Moritz Treeck
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, UK
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA
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4
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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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5
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Chen K, Huang X, Distler U, Tenzer S, Günay-Esiyok Ö, Gupta N. Apically-located P4-ATPase1-Lem1 complex internalizes phosphatidylserine and regulates motility-dependent invasion and egress in Toxoplasma gondii. Comput Struct Biotechnol J 2023; 21:1893-1906. [PMID: 36936814 PMCID: PMC10015115 DOI: 10.1016/j.csbj.2023.02.032] [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: 11/25/2022] [Revised: 02/17/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023] Open
Abstract
The membrane asymmetry regulated by P4-ATPases is crucial for the functioning of eukaryotic cells. The underlying spatial translocation or flipping of specific lipids is usually assured by respective P4-ATPases coupled to conforming non-catalytic subunits. Our previous work has identified five P4-ATPases (TgP4-ATPase1-5) and three non-catalytic partner proteins (TgLem1-3) in the intracellular protozoan pathogen, Toxoplasma gondii. However, their flipping activity, physiological relevance and functional coupling remain unknown. Herein, we demonstrate that TgP4-ATPase1 and TgLem1 work together to translocate phosphatidylserine (PtdSer) during the lytic cycle of T. gondii. Both proteins localize in the plasma membrane at the invasive (apical) end of its acutely-infectious tachyzoite stage. The genetic knockout of P4-ATPase1 and conditional depletion of Lem1 in tachyzoites severely disrupt the asexual reproduction and translocation of PtdSer across the plasma membrane. Moreover, the phenotypic analysis of individual mutants revealed a requirement of lipid flipping for the motility, egress and invasion of tachyzoites. Not least, the proximity-dependent biotinylation and reciprocal immunoprecipitation assays demonstrated the physical interaction of P4-ATPase1 and Lem1. Our findings disclose the mechanism and significance of PtdSer flipping during the lytic cycle and identify the P4-ATPase1-Lem1 heterocomplex as a potential drug target in T. gondii.
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Key Words
- BSA, bovine serum albumin
- CDC50, Cell Division Control 50
- COS, crossover sequence
- Cdc50
- DAPI, 4′,6-diamidino-2-phenylindole
- DHFR-TS, dihydrofolate reductase – thymidylate synthase
- HFF, human foreskin fibroblast
- HXGPRT, hypoxanthine-xanthine-guanine phosphoribosyltransferase
- IAA, indole-3-acetic acid
- LEM, Ligand Effector Module
- Lem1
- NBD, nitrobenzoxadiazole
- NBD-lipid
- P4-ATPase1
- PBS, phosphate-buffered saline
- Phosphatidylserine
- Phospholipid flipping
- PtdCho, phosphatidylcholine
- PtdEtn, phosphatidylethanolamine
- PtdSer, phosphatidylserine
- PtdThr, phosphatidylthreonine
- UTR, untranslated region
- cGMP, cyclic Guanosine Monophosphate
- mAID, (mini) auxin-inducible degron
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Affiliation(s)
- Kai Chen
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Xiyu Huang
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Ute Distler
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University, Mainz, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University, Mainz, Germany
| | - Özlem Günay-Esiyok
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
- Intracellular Parasite Education and Research Labs (iPEARL), Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-P), Hyderabad, India
- Corresponding author at: Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany.
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6
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Oliveira Souza RO, Jacobs KN, Back PS, Bradley PJ, Arrizabalaga G. IMC10 and LMF1 mediate mitochondrial morphology through mitochondrion-pellicle contact sites in Toxoplasma gondii. J Cell Sci 2022; 135:279336. [PMID: 36314270 PMCID: PMC9845740 DOI: 10.1242/jcs.260083] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022] Open
Abstract
The single mitochondrion of Toxoplasma gondii is highly dynamic, being predominantly in a peripherally distributed lasso-shape in intracellular parasites and collapsed in extracellular parasites. The peripheral positioning of the mitochondrion is associated with apparent contacts between the mitochondrion membrane and the parasite pellicle. The outer mitochondrial membrane-associated protein LMF1 is critical for the correct positioning of the mitochondrion. Intracellular parasites lacking LMF1 fail to form the lasso-shaped mitochondrion. To identify other proteins that tether the mitochondrion of the parasite to the pellicle, we performed a yeast two-hybrid screen for LMF1 interactors. We identified 70 putative interactors localized in different cellular compartments, such as the apical end of the parasite, mitochondrial membrane and the inner membrane complex (IMC), including with the pellicle protein IMC10. Using protein-protein interaction assays, we confirmed the interaction of LMF1 with IMC10. Conditional knockdown of IMC10 does not affect parasite viability but severely affects mitochondrial morphology in intracellular parasites and mitochondrial distribution to the daughter cells during division. In effect, IMC10 knockdown phenocopies disruption of LMF1, suggesting that these two proteins define a novel membrane tether between the mitochondrion and the IMC in Toxoplasma. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
| | - Kylie N. Jacobs
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Peter S. Back
- Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
| | - Peter J. Bradley
- Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA,Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA 90095, USA
| | - Gustavo Arrizabalaga
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA,Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA,Author for correspondence ()
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7
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A Signaling Factor Linked to Toxoplasma gondii Guanylate Cyclase Complex Controls Invasion and Egress during Acute and Chronic Infection. mBio 2022; 13:e0196522. [PMID: 36200777 PMCID: PMC9600588 DOI: 10.1128/mbio.01965-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Toxoplasma gondii is an intracellular apicomplexan parasite that relies on cyclic GMP (cGMP)-dependent signaling to trigger timely egress from host cells in response to extrinsic and intrinsic signals. A guanylate cyclase (GC) complex, conserved across the Apicomplexa, plays a pivotal role in integrating these signals, such as the key lipid mediator phosphatidic acid and changes in pH and ionic composition. This complex is composed of an atypical GC fused to a flippase-like P4-ATPase domain and assembled with the cell division control protein CDC50.1 and a unique GC organizer (UGO). While the dissemination of the fast-replicating tachyzoites responsible for acute infection is well understood, it is less clear if the cyst-forming bradyzoites can disseminate and contribute to cyst burden. Here, we characterized a novel component of the GC complex recently termed signaling linking factor (SLF). Tachyzoites conditionally depleted in SLF are impaired in microneme exocytosis, conoid extrusion, and motility and hence unable to invade and egress. A stage-specific promoter swap strategy allowed the generation of SLF- and GC-deficient bradyzoites that are viable as tachyzoites but show a reduction in cyst burden during the onset of chronic infection. Upon oral infection, SLF-deficient cysts failed to establish infection in mice, suggesting SLF's importance for the natural route of T. gondii infection. IMPORTANCE Toxoplasma gondii is an obligate intracellular parasite of the phylum Apicomplexa. This life-threatening opportunistic pathogen establishes a chronic infection in human and animals that is resistant to immune attacks and chemotherapeutic intervention. The slow-growing parasites persist in tissue cysts that constitute a predominant source of transmission. Host cell invasion and egress are two critical steps of the parasite lytic cycle that are governed by a guanylate cyclase complex conserved across the Apicomplexa. A signaling linked factor is characterized here as an additional component of the complex that not only is essential during acute infection but also plays a pivotal role during natural oral infection with tissue cysts' dissemination and persistence.
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Nofal SD, Dominicus C, Broncel M, Katris NJ, Flynn HR, Arrizabalaga G, Botté CY, Invergo BM, Treeck M. A positive feedback loop mediates crosstalk between calcium, cyclic nucleotide and lipid signalling in calcium-induced Toxoplasma gondii egress. PLoS Pathog 2022; 18:e1010901. [PMID: 36265000 PMCID: PMC9624417 DOI: 10.1371/journal.ppat.1010901] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/01/2022] [Accepted: 09/29/2022] [Indexed: 11/25/2022] Open
Abstract
Fundamental processes that govern the lytic cycle of the intracellular parasite Toxoplasma gondii are regulated by several signalling pathways. However, how these pathways are connected remains largely unknown. Here, we compare the phospho-signalling networks during Toxoplasma egress from its host cell by artificially raising cGMP or calcium levels. We show that both egress inducers trigger indistinguishable signalling responses and provide evidence for a positive feedback loop linking calcium and cyclic nucleotide signalling. Using WT and conditional knockout parasites of the non-essential calcium-dependent protein kinase 3 (CDPK3), which display a delay in calcium inonophore-mediated egress, we explore changes in phosphorylation and lipid signalling in sub-minute timecourses after inducing Ca2+ release. These studies indicate that cAMP and lipid metabolism are central to the feedback loop, which is partly dependent on CDPK3 and allows the parasite to respond faster to inducers of egress. Biochemical analysis of 4 phosphodiesterases (PDEs) identified in our phosphoproteomes establishes PDE2 as a cAMP-specific PDE which regulates Ca2+ induced egress in a CDPK3-independent manner. The other PDEs display dual hydrolytic activity and play no role in Ca2+ induced egress. In summary, we uncover a positive feedback loop that enhances signalling during egress, thereby linking several signalling pathways.
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Affiliation(s)
- Stephanie D. Nofal
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Caia Dominicus
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Malgorzata Broncel
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
- Protein Analysis and Proteomics Platform, The Francis Crick Institute, London, United Kingdom
| | - Nicholas J. Katris
- Apicolipid Team, Institute for Advance Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Helen R. Flynn
- Protein Analysis and Proteomics Platform, The Francis Crick Institute, London, United Kingdom
| | - Gustavo Arrizabalaga
- University of Indianapolis, School of Medicine, Indianapolis, Indiana, United States of America
| | - Cyrille Y. Botté
- Apicolipid Team, Institute for Advance Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Brandon M. Invergo
- Translational Research Exchange at Exeter, University of Exeter, Exeter, United Kingdom
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
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9
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CDC50 Orthologues in Plasmodium falciparum Have Distinct Roles in Merozoite Egress and Trophozoite Maturation. mBio 2022; 13:e0163522. [PMID: 35862778 PMCID: PMC9426505 DOI: 10.1128/mbio.01635-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In model organisms, type IV ATPases (P4-ATPases) require cell division control protein 50 (CDC50) chaperones for their phospholipid flipping activity. In the malaria parasite Plasmodium falciparum, guanylyl cyclase alpha (GCα) is an integral membrane protein that is essential for release (egress) of merozoites from their host erythrocytes. GCα is unusual in that it contains both a C-terminal cyclase domain and an N-terminal P4-ATPase domain of unknown function. We sought to investigate whether any of the three CDC50 orthologues (termed A, B, and C) encoded by P. falciparum are required for GCα function. Using gene tagging and conditional gene disruption, we demonstrate that CDC50B and CDC50C but not CDC50A are expressed in the clinically important asexual blood stages and that CDC50B is a binding partner of GCα whereas CDC50C is the binding partner of another putative P4-ATPase, phospholipid-transporting ATPase 2 (ATP2). Our findings indicate that CDC50B has no essential role for intraerythrocytic parasite maturation but modulates the rate of parasite egress by interacting with GCα for optimal cGMP synthesis. In contrast, CDC50C is essential for blood stage trophozoite maturation. Additionally, we find that the CDC50C-ATP2 complex may influence parasite endocytosis of host cell hemoglobin and consequently hemozoin formation.
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10
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Santos JM, Frénal K. Dominique Soldati-Favre: Bringing Toxoplasma gondii to the Molecular World. Front Cell Infect Microbiol 2022; 12:910611. [PMID: 35711657 PMCID: PMC9196188 DOI: 10.3389/fcimb.2022.910611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 04/29/2022] [Indexed: 11/25/2022] Open
Affiliation(s)
- Joana M Santos
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Karine Frénal
- Université Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
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11
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Screening the Toxoplasma kinome with high-throughput tagging identifies a regulator of invasion and egress. Nat Microbiol 2022; 7:868-881. [PMID: 35484233 PMCID: PMC9167752 DOI: 10.1038/s41564-022-01104-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/11/2022] [Indexed: 12/26/2022]
Abstract
Protein kinases regulate fundamental aspects of eukaryotic cell biology, making them attractive chemotherapeutic targets in parasites like Plasmodium spp. and Toxoplasma gondii. To systematically examine the parasite kinome, we developed a high-throughput tagging (HiT) strategy to endogenously label protein kinases with an auxin-inducible degron and fluorophore. Hundreds of tagging vectors were assembled from synthetic sequences in a single reaction and used to generate pools of mutants to determine localization and function. Examining 1,160 arrayed clones, we assigned 40 protein localizations and associated 15 kinases with distinct defects. The fitness of tagged alleles was also measured by pooled screening, distinguishing delayed from acute phenotypes. A previously unstudied kinase, associated with delayed loss, was shown to be a regulator of invasion and egress. We named the kinase Store Potentiating/Activating Regulatory Kinase (SPARK), based on its impact on intracellular Ca2+ stores. Despite homology to mammalian PDK1, SPARK lacks a lipid-binding domain, suggesting a rewiring of the pathway in parasites. HiT screening extends genome-wide approaches into complex cellular phenotypes, providing a scalable and versatile platform to dissect parasite biology.
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12
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Bisio H, Krishnan A, Marq JB, Soldati-Favre D. Toxoplasma gondii phosphatidylserine flippase complex ATP2B-CDC50.4 critically participates in microneme exocytosis. PLoS Pathog 2022; 18:e1010438. [PMID: 35325010 PMCID: PMC8982854 DOI: 10.1371/journal.ppat.1010438] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 04/05/2022] [Accepted: 03/11/2022] [Indexed: 12/22/2022] Open
Abstract
Regulated microneme secretion governs motility, host cell invasion and egress in the obligate intracellular apicomplexans. Intracellular calcium oscillations and phospholipid dynamics critically regulate microneme exocytosis. Despite its importance for the lytic cycle of these parasites, molecular mechanistic details about exocytosis are still missing. Some members of the P4-ATPases act as flippases, changing the phospholipid distribution by translocation from the outer to the inner leaflet of the membrane. Here, the localization and function of the repertoire of P4-ATPases was investigated across the lytic cycle of Toxoplasma gondii. Of relevance, ATP2B and the non-catalytic subunit cell division control protein 50.4 (CDC50.4) form a stable heterocomplex at the parasite plasma membrane, essential for microneme exocytosis. This complex is responsible for flipping phosphatidylserine, which presumably acts as a lipid mediator for organelle fusion with the plasma membrane. Overall, this study points toward the importance of phosphatidylserine asymmetric distribution at the plasma membrane for microneme exocytosis. Biological membranes display diverse functions, including membrane fusion, which are conferred by a defined composition and organization of proteins and lipids. Apicomplexan parasites possess specialized secretory organelles (micronemes), implicated in motility, invasion and egress from host cells. Microneme exocytosis is already known to depend on phosphatidic acid for its fusion with the plasma membrane. Here we identify a type P4-ATPase and its CDC50 chaperone (ATP2B-CDC50.4) that act as a flippase and contribute to the enrichment of phosphatidylserine (PS) in the inner leaflet of the parasite plasma membrane. The disruption of PS asymmetric distribution at the plasma membrane impacts microneme exocytosis. Overall, our results shed light on the importance of membrane homeostasis and lipid composition in controlling microneme secretion.
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Affiliation(s)
- Hugo Bisio
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Aarti Krishnan
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Jean-Baptiste Marq
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- * E-mail:
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13
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Abstract
Toxoplasma motility is both activated and suppressed by 3′,5′-cyclic nucleotide signaling. Cyclic GMP (cGMP) signaling through Toxoplasma gondii protein kinase G (TgPKG) activates motility, whereas cyclic AMP (cAMP) signaling through TgPKAc1 inhibits motility. Despite their importance, it remains unclear how cGMP and cAMP levels are maintained in Toxoplasma. Phosphodiesterases (PDEs) are known to inactivate cyclic nucleotides and are highly expanded in the Toxoplasma genome. Here, we analyzed the expression and function of the 18-member TgPDE family in tachyzoites, the virulent life stage of Toxoplasma. We detected the expression of 11 of 18 TgPDEs, confirming prior expression studies. A knockdown screen of the TgPDE family revealed four TgPDEs that contribute to lytic Toxoplasma growth (TgPDE1, TgPDE2, TgPDE5, and TgPDE9). Depletion of TgPDE1 or TgPDE2 caused severe growth defects, prompting further investigation. While TgPDE1 was important for extracellular motility, TgPDE2 was important for host cell invasion, parasite replication, host cell egress, and extracellular motility. TgPDE1 displayed a plasma membrane/cytomembranous distribution, whereas TgPDE2 displayed an endoplasmic reticulum/cytomembranous distribution. Biochemical analysis of TgPDE1 and TgPDE2 purified from Toxoplasma lysates revealed that TgPDE1 hydrolyzes both cGMP and cAMP, whereas TgPDE2 was cAMP specific. Interactome studies of TgPDE1 and TgPDE2 indicated that they do not physically interact with each other or other TgPDEs but may be regulated by kinases and proteases. Our studies have identified TgPDE1 and TgPDE2 as central regulators of tachyzoite cyclic nucleotide levels and enable future studies aimed at determining how these enzymes are regulated and cooperate to control Toxoplasma motility and growth. IMPORTANCE Apicomplexan parasites require motility to actively infect host cells and cause disease. Cyclic nucleotide signaling governs apicomplexan motility, but it is unclear how cyclic nucleotide levels are maintained in these parasites. In search of novel regulators of cyclic nucleotides in the model apicomplexan Toxoplasma, we identified and characterized two catalytically active phosphodiesterases, TgPDE1 and TgPDE2, that are important for Toxoplasma’s virulent tachyzoite life cycle. Enzymes that generate, sense, or degrade cyclic nucleotides make attractive targets for therapies aimed at paralyzing and killing apicomplexan parasites.
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14
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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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15
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Calcium signaling in intracellular protist parasites. Curr Opin Microbiol 2021; 64:33-40. [PMID: 34571430 DOI: 10.1016/j.mib.2021.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/28/2021] [Accepted: 09/07/2021] [Indexed: 11/21/2022]
Abstract
Calcium ion (Ca2+) signaling is one of the most frequently employed mechanisms of signal transduction by eukaryotic cells, and starts with either Ca2+ release from intracellular stores or Ca2+ entry through the plasma membrane. In intracellular protist parasites Ca2+ signaling initiates a sequence of events that may facilitate their invasion of host cells, respond to environmental changes within the host, or regulate the function of their intracellular organelles. In this review we examine recent findings in Ca2+ signaling in two groups of intracellular protist parasites that have been studied in more detail, the apicomplexan and the trypanosomatid parasites.
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Nofal SD, Patel A, Blackman MJ, Flueck C, Baker DA. Plasmodium falciparum Guanylyl Cyclase-Alpha and the Activity of Its Appended P4-ATPase Domain Are Essential for cGMP Synthesis and Blood-Stage Egress. mBio 2021; 12:e02694-20. [PMID: 33500341 PMCID: PMC7858053 DOI: 10.1128/mbio.02694-20] [Citation(s) in RCA: 9] [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: 09/21/2020] [Accepted: 11/19/2020] [Indexed: 12/16/2022] Open
Abstract
Guanylyl cyclases (GCs) synthesize cyclic GMP (cGMP) and, together with cyclic nucleotide phosphodiesterases, are responsible for regulating levels of this intracellular messenger which mediates myriad functions across eukaryotes. In malaria parasites (Plasmodium spp), as well as their apicomplexan and ciliate relatives, GCs are associated with a P4-ATPase-like domain in a unique bifunctional configuration. P4-ATPases generate membrane bilayer lipid asymmetry by translocating phospholipids from the outer to the inner leaflet. Here, we investigate the role of Plasmodium falciparum guanylyl cyclase alpha (GCα) and its associated P4-ATPase module, showing that asexual blood-stage parasites lacking both the cyclase and P4-ATPase domains are unable to egress from host erythrocytes. GCα-null parasites cannot synthesize cGMP or mobilize calcium, a cGMP-dependent protein kinase (PKG)-driven requirement for egress. Using chemical complementation with a cGMP analogue and point mutagenesis of a crucial conserved residue within the P4-ATPase domain, we show that P4-ATPase activity is upstream of and linked to cGMP synthesis. Collectively, our results demonstrate that GCα is a critical regulator of PKG and that its associated P4-ATPase domain plays a primary role in generating cGMP for merozoite egress.IMPORTANCE The clinical manifestations of malaria arise due to successive rounds of replication of Plasmodium parasites within red blood cells. Once mature, daughter merozoites are released from infected erythrocytes to invade new cells in a tightly regulated process termed egress. Previous studies have shown that the activation of cyclic GMP (cGMP) signaling is critical for initiating egress. Here, we demonstrate that GCα, a unique bifunctional enzyme, is the sole enzyme responsible for cGMP production during the asexual blood stages of Plasmodium falciparum and is required for the cellular events leading up to merozoite egress. We further demonstrate that in addition to the GC domain, the appended ATPase-like domain of GCα is also involved in cGMP production. Our results highlight the critical role of GCα in cGMP signaling required for orchestrating malaria parasite egress.
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Affiliation(s)
- Stephanie D Nofal
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Avnish Patel
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Michael J Blackman
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Malaria Biochemistry Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Christian Flueck
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David A Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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17
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Chen K, Günay-Esiyok Ö, Klingeberg M, Marquardt S, Pomorski TG, Gupta N. Aminoglycerophospholipid flipping and P4-ATPases in Toxoplasma gondii. J Biol Chem 2021; 296:100315. [PMID: 33485966 PMCID: PMC7949121 DOI: 10.1016/j.jbc.2021.100315] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 12/29/2020] [Accepted: 01/13/2021] [Indexed: 11/30/2022] Open
Abstract
Lipid flipping in the membrane bilayers is a widespread eukaryotic phenomenon that is catalyzed by assorted P4-ATPases. Its occurrence, mechanism, and importance in apicomplexan parasites have remained elusive, however. Here we show that Toxoplasma gondii, an obligate intracellular parasite with high clinical relevance, can salvage phosphatidylserine (PtdSer) and phosphatidylethanolamine (PtdEtn) but not phosphatidylcholine (PtdCho) probes from its milieu. Consistently, the drug analogs of PtdCho are broadly ineffective in the parasite culture. NBD-PtdSer imported to the parasite interior is decarboxylated to NBD-PtdEtn, while the latter is not methylated to yield PtdCho, which confirms the expression of PtdSer decarboxylase but a lack of PtdEtn methyltransferase activity and suggests a role of exogenous lipids in membrane biogenesis of T. gondii. Flow cytometric quantitation of NBD-probes endorsed the selectivity of phospholipid transport and revealed a dependence of the process on energy and protein. Accordingly, our further work identified five P4-ATPases (TgP4-ATPase1-5), all of which harbor the signature residues and motifs required for phospholipid flipping. Of the four proteins expressed during the lytic cycle, TgP4-ATPase1 is present in the apical plasmalemma; TgP4-ATPase3 resides in the Golgi network along with its noncatalytic partner Ligand Effector Module 3 (TgLem3), whereas TgP4-ATPase2 and TgP4-ATPase5 localize in the plasmalemma as well as endo/cytomembranes. Last but not least, auxin-induced degradation of TgP4-ATPase1-3 impaired the parasite growth in human host cells, disclosing their crucial roles during acute infection. In conclusion, we show selective translocation of PtdEtn and PtdSer at the parasite surface and provide the underlying mechanistic and physiological insights in a model eukaryotic pathogen.
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Affiliation(s)
- Kai Chen
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Özlem Günay-Esiyok
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Melissa Klingeberg
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Stephan Marquardt
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany; Department of Experimental Biophysics, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Thomas Günther Pomorski
- Department of Experimental Biophysics, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, 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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18
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Uboldi AD, Wilde ML, Bader SM, Tonkin CJ. Environmental sensing and regulation of motility in Toxoplasma. Mol Microbiol 2020; 115:916-929. [PMID: 33278047 DOI: 10.1111/mmi.14661] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/27/2020] [Accepted: 12/01/2020] [Indexed: 12/28/2022]
Abstract
Toxoplasma and other apicomplexan parasites undergo a unique form of cellular locomotion referred to as "gliding motility." Gliding motility is crucial for parasite survival as it powers tissue dissemination, host cell invasion and egress. Distinct environmental cues lead to activation of gliding motility and have become a prominent focus of recent investigation. Progress has been made toward understanding what environmental cues are sensed and how these signals are transduced in order to regulate the machinery and cellular events powering gliding motility. In this review, we will discuss new findings and integrate these into our current understanding to propose a model of how environmental sensing is achieved to regulate gliding motility in Toxoplasma. Collectively, these findings also have implications for the understanding of gliding motility across Apicomplexa more broadly.
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Affiliation(s)
- Alessandro D Uboldi
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Mary-Louise Wilde
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Stefanie M Bader
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Christopher J Tonkin
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
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19
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Vo KC, Günay-Esiyok Ö, Liem N, Gupta N. The protozoan parasite Toxoplasma gondii encodes a gamut of phosphodiesterases during its lytic cycle in human cells. Comput Struct Biotechnol J 2020; 18:3861-3876. [PMID: 33335684 PMCID: PMC7720076 DOI: 10.1016/j.csbj.2020.11.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 01/21/2023] Open
Abstract
Toxoplasma genome harbors at least 18 phosphodiesterases encoded by distinct genes. Most parasite PDEs lack regulatory modules and are quite divergent from their human orthologs. Acutely-infectious tachyzoite stage of T. gondii expresses 11 PDEs with varied localizations. PDE8 and PDE9 are closely-related dual-substrate specific proteins residing in the apical pole. Homology modeling of PDE8 and PDE9 reveals a conserved 3D topology and substrate pocket. PDE9 is dispensable in tachyzoites, signifying a functional redundancy with PDE8.
Cyclic nucleotide signaling is pivotal to the asexual reproduction of Toxoplasma gondii, however little do we know about the phosphodiesterase enzymes in this widespread obligate intracellular parasite. Here, we identified 18 phosphodiesterases (TgPDE1-18) in the parasite genome, most of which form apicomplexan-specific clades and lack archetypal regulatory motifs often found in mammalian PDEs. Genomic epitope-tagging in the tachyzoite stage showed the expression of 11 phosphodiesterases with diverse subcellular distributions. Notably, TgPDE8 and TgPDE9 are located in the apical plasma membrane to regulate cAMP and cGMP signaling, as suggested by their dual-substrate catalysis and structure modeling. TgPDE9 expression can be ablated with no apparent loss of growth fitness in tachyzoites. Likewise, the redundancy in protein expression, subcellular localization and predicted substrate specificity of several other PDEs indicate significant plasticity and spatial control of cyclic nucleotide signaling during the lytic cycle. Our findings shall enable a rational dissection of signaling in tachyzoites by combinatorial mutagenesis. Moreover, the phylogenetic divergence of selected Toxoplasma PDEs from human counterparts can be exploited to develop parasite-specific inhibitors and therapeutics.
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Key Words
- 3′IT, 3′-insertional tagging
- AC, adenylate cyclase
- Apicomplexa
- Bradyzoite
- COS, crossover sequence
- CRISPR, clustered regularly interspaced short palindromic repeats
- EES, entero-epithelial stages
- FPKM, fragments per kilobase of exon model per million
- GC, guanylate cyclase
- GMQE, Global Model Quality Estimation
- HFF, human foreskin fibroblast
- HXGPRT, hypoxanthine-xanthine-guanine phosphoribosyltransferase
- IMC, inner membrane complex
- Lytic cycle
- MAEBL, merozoite adhesive erythrocytic binding ligand
- MOI, multiplicity of infection
- OCRE, octamer repeat
- PDE, phosphodiesterase
- PKA, protein kinase A
- PKG, protein kinase G
- PM, plasma membrane
- QMEAN, Quality Model Energy Analysis
- Tachyzoite
- cAMP and 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
| | - Özlem Günay-Esiyok
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nicolas Liem
- Experimental Biophysics, 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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20
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Paul AS, Miliu A, Paulo JA, Goldberg JM, Bonilla AM, Berry L, Seveno M, Braun-Breton C, Kosber AL, Elsworth B, Arriola JSN, Lebrun M, Gygi SP, Lamarque MH, Duraisingh MT. Co-option of Plasmodium falciparum PP1 for egress from host erythrocytes. Nat Commun 2020; 11:3532. [PMID: 32669539 PMCID: PMC7363832 DOI: 10.1038/s41467-020-17306-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 06/19/2020] [Indexed: 12/20/2022] Open
Abstract
Asexual proliferation of the Plasmodium parasites that cause malaria follows a developmental program that alternates non-canonical intraerythrocytic replication with dissemination to new host cells. We carried out a functional analysis of the Plasmodium falciparum homolog of Protein Phosphatase 1 (PfPP1), a universally conserved cell cycle factor in eukaryotes, to investigate regulation of parasite proliferation. PfPP1 is indeed required for efficient replication, but is absolutely essential for egress of parasites from host red blood cells. By phosphoproteomic and chemical-genetic analysis, we isolate two functional targets of PfPP1 for egress: a HECT E3 protein-ubiquitin ligase; and GCα, a fusion protein composed of a guanylyl cyclase and a phospholipid transporter domain. We hypothesize that PfPP1 regulates lipid sensing by GCα and find that phosphatidylcholine stimulates PfPP1-dependent egress. PfPP1 acts as a key regulator that integrates multiple cell-intrinsic pathways with external signals to direct parasite egress from host cells.
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Affiliation(s)
- Aditya S Paul
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Alexandra Miliu
- Laboratory of Pathogen Host Interaction (LPHI), UMR5235, Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34095, Montpellier, France
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, 02115, MA, USA
| | - Jonathan M Goldberg
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Arianna M Bonilla
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Laurence Berry
- Laboratory of Pathogen Host Interaction (LPHI), UMR5235, Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34095, Montpellier, France
| | - Marie Seveno
- Laboratory of Pathogen Host Interaction (LPHI), UMR5235, Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34095, Montpellier, France
| | - Catherine Braun-Breton
- Laboratory of Pathogen Host Interaction (LPHI), UMR5235, Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34095, Montpellier, France
| | - Aziz L Kosber
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Brendan Elsworth
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Jose S N Arriola
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA
| | - Maryse Lebrun
- Laboratory of Pathogen Host Interaction (LPHI), UMR5235, Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34095, Montpellier, France
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, 02115, MA, USA
| | - Mauld H Lamarque
- Laboratory of Pathogen Host Interaction (LPHI), UMR5235, Centre National de la Recherche Scientifique (CNRS), Université de Montpellier, 34095, Montpellier, France.
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, 02115, MA, USA.
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21
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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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22
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Jiang Y, Wei J, Cui H, Liu C, Zhi Y, Jiang Z, Li Z, Li S, Yang Z, Wang X, Qian P, Zhang C, Zhong C, Su XZ, Yuan J. An intracellular membrane protein GEP1 regulates xanthurenic acid induced gametogenesis of malaria parasites. Nat Commun 2020; 11:1764. [PMID: 32273496 PMCID: PMC7145802 DOI: 10.1038/s41467-020-15479-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 03/14/2020] [Indexed: 11/09/2022] Open
Abstract
Gametocytes differentiation to gametes (gametogenesis) within mosquitos is essential for malaria parasite transmission. Both reduction in temperature and mosquito-derived XA or elevated pH are required for triggering cGMP/PKG dependent gametogenesis. However, the parasite molecule for sensing or transducing these environmental signals to initiate gametogenesis remains unknown. Here we perform a CRISPR/Cas9-based functional screening of 59 membrane proteins expressed in the gametocytes of Plasmodium yoelii and identify that GEP1 is required for XA-stimulated gametogenesis. GEP1 disruption abolishes XA-stimulated cGMP synthesis and the subsequent signaling and cellular events, such as Ca2+ mobilization, gamete formation, and gametes egress out of erythrocytes. GEP1 interacts with GCα, a cGMP synthesizing enzyme in gametocytes. Both GEP1 and GCα are expressed in cytoplasmic puncta of both male and female gametocytes. Depletion of GCα impairs XA-stimulated gametogenesis, mimicking the defect of GEP1 disruption. The identification of GEP1 being essential for gametogenesis provides a potential new target for intervention of parasite transmission.
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Affiliation(s)
- Yuanyuan Jiang
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Jun Wei
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Huiting Cui
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Chuanyuan Liu
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Yuan Zhi
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - ZhengZheng Jiang
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Zhenkui Li
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Shaoneng Li
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Zhenke Yang
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Xu Wang
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Pengge Qian
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Cui Zhang
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Chuanqi Zhong
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China
| | - Xin-Zhuan Su
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jing Yuan
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, 361102, Xiamen, Fujian, China.
- Lingnan Guangdong Laboratory of Modern Agriculture, 510642, Guangzhou, China.
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23
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Günay-Esiyok Ö, Gupta N. Chimeras of P4-ATPase and Guanylate Cyclase in Pathogenic Protists. Trends Parasitol 2020; 36:382-392. [DOI: 10.1016/j.pt.2020.01.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 02/07/2023]
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24
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Abstract
Understanding the mechanisms behind host cell invasion by Plasmodium falciparum remains a major hurdle to developing antimalarial therapeutics that target the asexual cycle and the symptomatic stage of malaria. Host cell entry is enabled by a multitude of precisely timed and tightly regulated receptor-ligand interactions. Cyclic nucleotide signaling has been implicated in regulating parasite invasion, and an important downstream effector of the cAMP-signaling pathway is protein kinase A (PKA), a cAMP-dependent protein kinase. There is increasing evidence that P. falciparum PKA (PfPKA) is responsible for phosphorylation of the cytoplasmic domain of P. falciparum apical membrane antigen 1 (PfAMA1) at Ser610, a cAMP-dependent event that is crucial for successful parasite invasion. In the present study, CRISPR-Cas9 and conditional gene deletion (dimerizable cre) technologies were implemented to generate a P. falciparum parasite line in which expression of the catalytic subunit of PfPKA (PfPKAc) is under conditional control, demonstrating highly efficient dimerizable Cre recombinase (DiCre)-mediated gene excision and complete knockdown of protein expression. Parasites lacking PfPKAc show severely reduced growth after one intraerythrocytic growth cycle and are deficient in host cell invasion, as highlighted by live-imaging experiments. Furthermore, PfPKAc-deficient parasites are unable to phosphorylate PfAMA1 at Ser610. This work not only identifies an essential role for PfPKAc in the P. falciparum asexual life cycle but also confirms that PfPKAc is the kinase responsible for phosphorylating PfAMA1 Ser610.IMPORTANCE Malaria continues to present a major global health burden, particularly in low-resource countries. Plasmodium falciparum, the parasite responsible for the most severe form of malaria, causes disease through rapid and repeated rounds of invasion and replication within red blood cells. Invasion into red blood cells is essential for P. falciparum survival, and the molecular events mediating this process have gained much attention as potential therapeutic targets. With no effective vaccine available, and with the emergence of resistance to antimalarials, there is an urgent need for the development of new therapeutics. Our research has used genetic techniques to provide evidence of an essential protein kinase involved in P. falciparum invasion. Our work adds to the current understanding of parasite signaling processes required for invasion, highlighting PKA as a potential drug target to inhibit invasion for the treatment of malaria.
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Günay-Esiyok Ö, Scheib U, Noll M, Gupta N. An unusual and vital protein with guanylate cyclase and P4-ATPase domains in a pathogenic protist. Life Sci Alliance 2019; 2:2/3/e201900402. [PMID: 31235476 PMCID: PMC6592433 DOI: 10.26508/lsa.201900402] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 06/06/2019] [Accepted: 06/06/2019] [Indexed: 12/13/2022] Open
Abstract
Toxoplasma gondii harbors an alveolate-specific guanylate cyclase linked to P-type ATPase motifs, which is an essential actuator of cGMP-dependent gliding motility, egress, and invasion during acute infection. cGMP signaling is one of the master regulators of diverse functions in eukaryotes; however, its architecture and functioning in protozoans remain poorly understood. Herein, we report an exclusive guanylate cyclase coupled with N-terminal P4-ATPase in a common parasitic protist, Toxoplasma gondii. This bulky protein (477-kD), termed TgATPaseP-GC to fairly reflect its envisaged multifunctionality, localizes in the plasma membrane at the apical pole of the parasite, whereas the corresponding cGMP-dependent protein kinase (TgPKG) is distributed in the cytomembranes. TgATPaseP-GC is refractory to genetic deletion, and its CRISPR/Cas9–assisted disruption aborts the lytic cycle of T. gondii. Besides, Cre/loxP–mediated knockdown of TgATPaseP-GC reduced the synthesis of cGMP and inhibited the parasite growth due to impairments in the motility-dependent egress and invasion events. Equally, repression of TgPKG by a similar strategy recapitulated phenotypes of the TgATPaseP-GC–depleted mutant. Notably, despite a temporally restricted function, TgATPaseP-GC is expressed constitutively throughout the lytic cycle, entailing a post-translational regulation of cGMP signaling. Not least, the occurrence of TgATPaseP-GC orthologs in several other alveolates implies a divergent functional repurposing of cGMP signaling in protozoans, and offers an excellent drug target against the parasitic protists.
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Affiliation(s)
- Özlem Günay-Esiyok
- Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Ulrike Scheib
- Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Matthias Noll
- Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nishith Gupta
- Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
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