1
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Cabral G, Moss WJ, Brown KM. Proteomic approaches for protein kinase substrate identification in Apicomplexa. Mol Biochem Parasitol 2024; 259:111633. [PMID: 38821187 DOI: 10.1016/j.molbiopara.2024.111633] [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: 03/30/2024] [Revised: 05/10/2024] [Accepted: 05/28/2024] [Indexed: 06/02/2024]
Abstract
Apicomplexa is a phylum of protist parasites, notable for causing life-threatening diseases including malaria, toxoplasmosis, cryptosporidiosis, and babesiosis. Apicomplexan pathogenesis is generally a function of lytic replication, dissemination, persistence, host cell modification, and immune subversion. Decades of research have revealed essential roles for apicomplexan protein kinases in establishing infections and promoting pathogenesis. Protein kinases modify their substrates by phosphorylating serine, threonine, tyrosine, or other residues, resulting in rapid functional changes in the target protein. Post-translational modification by phosphorylation can activate or inhibit a substrate, alter its localization, or promote interactions with other proteins or ligands. Deciphering direct kinase substrates is crucial to understand mechanisms of kinase signaling, yet can be challenging due to the transient nature of kinase phosphorylation and potential for downstream indirect phosphorylation events. However, with recent advances in proteomic approaches, our understanding of kinase function in Apicomplexa has improved dramatically. Here, we discuss methods that have been used to identify kinase substrates in apicomplexan parasites, classifying them into three main categories: i) kinase interactome, ii) indirect phosphoproteomics and iii) direct labeling. We briefly discuss each approach, including their advantages and limitations, and highlight representative examples from the Apicomplexa literature. Finally, we conclude each main category by introducing prospective approaches from other fields that would benefit kinase substrate identification in Apicomplexa.
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Affiliation(s)
- Gabriel Cabral
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - William J Moss
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Kevin M Brown
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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2
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Herneisen AL, Peters ML, Smith TA, Shortt E, Lourido S. SPARK regulates AGC kinases central to the Toxoplasma gondii asexual cycle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.30.564746. [PMID: 37961644 PMCID: PMC10634940 DOI: 10.1101/2023.10.30.564746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Apicomplexan parasites balance proliferation, persistence, and spread in their metazoan hosts. AGC kinases, such as PKG, PKA, and the PDK1 ortholog SPARK, integrate environmental signals to toggle parasites between replicative and motile life stages. Recent studies have cataloged pathways downstream of apicomplexan PKG and PKA; however, less is known about the global integration of AGC kinase signaling cascades. Here, conditional genetics coupled to unbiased proteomics demonstrates that SPARK complexes with an elongin-like protein to regulate the stability of PKA and PKG in the model apicomplexan Toxoplasma gondii. Defects attributed to SPARK depletion develop after PKG and PKA are down-regulated. Parasites lacking SPARK differentiate into the chronic form of infection, which may arise from reduced activity of a coccidian-specific PKA ortholog. This work delineates the signaling topology of AGC kinases that together control transitions within the asexual cycle of this important family of parasites.
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Affiliation(s)
- Alice L. Herneisen
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Michelle L. Peters
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Tyler A. Smith
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Emily Shortt
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
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3
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Gilleran JA, Ashraf K, Delvillar M, Eck T, Fondekar R, Miller EB, Hutchinson A, Dong A, Seitova A, De Souza ML, Augeri D, Halabelian L, Siekierka J, Rotella DP, Gordon J, Childers WE, Grier MC, Staker BL, Roberge JY, Bhanot P. Structure-Activity Relationship of a Pyrrole Based Series of PfPKG Inhibitors as Anti-Malarials. J Med Chem 2024; 67:3467-3503. [PMID: 38372781 DOI: 10.1021/acs.jmedchem.3c01795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Controlling malaria requires new drugs against Plasmodium falciparum. The P. falciparum cGMP-dependent protein kinase (PfPKG) is a validated target whose inhibitors could block multiple steps of the parasite's life cycle. We defined the structure-activity relationship (SAR) of a pyrrole series for PfPKG inhibition. Key pharmacophores were modified to enable full exploration of chemical diversity and to gain knowledge about an ideal core scaffold. In vitro potency against recombinant PfPKG and human PKG were used to determine compound selectivity for the parasite enzyme. P. berghei sporozoites and P. falciparum asexual blood stages were used to assay multistage antiparasitic activity. Cellular specificity of compounds was evaluated using transgenic parasites expressing PfPKG carrying a substituted "gatekeeper" residue. The structure of PfPKG bound to an inhibitor was solved, and modeling using this structure together with computational tools was utilized to understand SAR and establish a rational strategy for subsequent lead optimization.
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Affiliation(s)
- John A Gilleran
- Rutgers Molecular Design and Synthesis Core, Office for Research, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, United States
| | - Kutub Ashraf
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, 225 Warren Street, Newark, New Jersey 07103, United States
| | - Melvin Delvillar
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, 225 Warren Street, Newark, New Jersey 07103, United States
| | - Tyler Eck
- Department of Chemistry and Biochemistry and Sokol Institute of Pharmaceutical Life Sciences, Montclair State University, Montclair, New Jersey 07043, United States
| | - Raheel Fondekar
- Rutgers Molecular Design and Synthesis Core, Office for Research, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, United States
- Rutgers School of Pharmacy, 160 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| | - Edward B Miller
- Schrödinger, Inc., 1540 Broadway, 24th Floor, New York, New York 10036, United States
| | - Ashley Hutchinson
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Aiping Dong
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Alma Seitova
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Mariana Laureano De Souza
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, 225 Warren Street, Newark, New Jersey 07103, United States
| | - David Augeri
- Rutgers Molecular Design and Synthesis Core, Office for Research, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, United States
- Schrödinger, Inc., 1540 Broadway, 24th Floor, New York, New York 10036, United States
| | - Levon Halabelian
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - John Siekierka
- Department of Chemistry and Biochemistry and Sokol Institute of Pharmaceutical Life Sciences, Montclair State University, Montclair, New Jersey 07043, United States
| | - David P Rotella
- Department of Chemistry and Biochemistry and Sokol Institute of Pharmaceutical Life Sciences, Montclair State University, Montclair, New Jersey 07043, United States
| | - John Gordon
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, Pennsylvania 19140, United States
| | - Wayne E Childers
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, Pennsylvania 19140, United States
| | - Mark C Grier
- Rutgers Molecular Design and Synthesis Core, Office for Research, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, United States
| | - Bart L Staker
- Seattle Structural Genomics Center for Infectious Disease, Seattle, Washington 98109, United States
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington 98109, United States
| | - Jacques Y Roberge
- Rutgers Molecular Design and Synthesis Core, Office for Research, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, United States
| | - Purnima Bhanot
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, 225 Warren Street, Newark, New Jersey 07103, United States
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4
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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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5
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Moss WJ, Brusini L, Kuehnel R, Brochet M, Brown KM. Apicomplexan phosphodiesterases in cyclic nucleotide turnover: conservation, function, and therapeutic potential. mBio 2024; 15:e0305623. [PMID: 38132724 PMCID: PMC10865986 DOI: 10.1128/mbio.03056-23] [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: 12/23/2023] Open
Abstract
Apicomplexa encompasses a large number of intracellular parasites infecting a wide range of animals. Cyclic nucleotide signaling is crucial for a variety of apicomplexan life stages and cellular processes. The cyclases and kinases that synthesize and respond to cyclic nucleotides (i.e., 3',5'-cyclic guanosine monophosphate and 3',5'-cyclic adenosine monophosphate) are highly conserved and essential throughout the parasite phylum. Growing evidence indicates that phosphodiesterases (PDEs) are also critical for regulating cyclic nucleotide signaling via cyclic nucleotide hydrolysis. Here, we discuss recent advances in apicomplexan PDE biology and opportunities for therapeutic interventions, with special emphasis on the major human apicomplexan parasite genera Plasmodium, Toxoplasma, Cryptosporidium, and Babesia. In particular, we show a highly flexible repertoire of apicomplexan PDEs associated with a wide range of cellular requirements across parasites and lifecycle stages. Despite this phylogenetic diversity, cellular requirements of apicomplexan PDEs for motility, host cell egress, or invasion are conserved. However, the molecular wiring of associated PDEs is extremely malleable suggesting that PDE diversity and redundancy are key for the optimization of cyclic nucleotide turnover to respond to the various environments encountered by each parasite and life stage. Understanding how apicomplexan PDEs are regulated and integrating multiple signaling systems into a unified response represent an untapped avenue for future exploration.
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Affiliation(s)
- William J. Moss
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Lorenzo Brusini
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Ronja Kuehnel
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Mathieu Brochet
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Kevin M. Brown
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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6
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Henry B, Sibley LD, Rosenberg A. A Combination of Four Nuclear Targeted Effectors Protects Toxoplasma Against Interferon Gamma Driven Human Host Cell Death During Acute Infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.24.573224. [PMID: 38234811 PMCID: PMC10793417 DOI: 10.1101/2023.12.24.573224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
In both mice and humans, Type II interferon-gamma (IFNγ) is crucial for regulation of Toxoplasma gondii (T. gondii) infection, during acute or chronic phases. To thwart this defense, T. gondii secretes protein effectors hindering the hosťs immune response. For example, T. gondii relies on the MYR translocon complex to deploy soluble dense granule effectors (GRAs) into the host cell cytosol or nucleus. Recent genome-wide loss-of-function screens in IFNγ-primed primary human fibroblasts identified MYR translocon components as crucial for parasite resistance against IFNγ driven vacuole clearance. However, these screens did not pinpoint specific MYR-dependent GRA proteins responsible for IFNγ signaling blockade, suggesting potential functional redundancy. Our study reveals that T. gondii depends on the MYR translocon complex to prevent host cell death and parasite premature egress in human cells stimulated with IFNγ postinfection, a unique phenotype observed in various human cell lines but not in murine cells. Intriguingly, inhibiting parasite egress did not prevent host cell death, indicating this mechanism is distinct from those described previously. Genome-wide loss-of-function screens uncovered TgIST, GRA16, GRA24, and GRA28 as effectors necessary for a complete block of IFNγ response. GRA24 and GRA28 directly influenced IFNγ driven transcription, GRA24's action depended on its interaction with p38 MAPK, while GRA28 disrupted histone acetyltransferase activity of CBP/p300. Given the intricate nature of the immune response to T. gondii, it appears that the parasite has evolved equally elaborate mechanisms to subvert IFNγ signaling, extending beyond direct interference with the JAK/STAT1 pathway, to encompass other signaling pathways as well.
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Affiliation(s)
- Brittany Henry
- Department of Infectious Diseases, Center for Tropical and Emerging Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, USA
| | - Alex Rosenberg
- Department of Infectious Diseases, Center for Tropical and Emerging Infectious Diseases, University of Georgia, Athens, Georgia, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, USA
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7
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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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8
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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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9
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Kovada V, Withers-Martinez C, Bobrovs R, Ce̅rule H, Liepins E, Grinberga S, Hackett F, Collins CR, Kreicberga A, Jiménez-Díaz MB, Angulo-Barturen I, Rasina D, Suna E, Jaudzems K, Blackman MJ, Jirgensons A. Macrocyclic Peptidomimetic Plasmepsin X Inhibitors with Potent In Vitro and In Vivo Antimalarial Activity. J Med Chem 2023; 66:10658-10680. [PMID: 37505188 PMCID: PMC10424242 DOI: 10.1021/acs.jmedchem.3c00812] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Indexed: 07/29/2023]
Abstract
The Plasmodium falciparum aspartic protease plasmepsin X (PMX) is essential for the egress of invasive merozoite forms of the parasite. PMX has therefore emerged as a new potential antimalarial target. Building on peptidic amino alcohols originating from a phenotypic screening hit, we have here developed a series of macrocyclic analogues as PMX inhibitors. Incorporation of an extended linker between the S1 phenyl group and S3 amide led to a lead compound that displayed a 10-fold improved PMX inhibitory potency and a 3-fold improved half-life in microsomal stability assays compared to the acyclic analogue. The lead compound was also the most potent of the new macrocyclic compounds in in vitro parasite growth inhibition. Inhibitor 7k cleared blood-stage P. falciparum in a dose-dependent manner when administered orally to infected humanized mice. Consequently, lead compound 7k represents a promising orally bioavailable molecule for further development as a PMX-targeting antimalarial drug.
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Affiliation(s)
- Vadims Kovada
- Latvian
Institute of Organic Synthesis, Riga LV-1006, Latvia
| | | | - Raitis Bobrovs
- Latvian
Institute of Organic Synthesis, Riga LV-1006, Latvia
| | - Hele̅na Ce̅rule
- Latvian
Institute of Organic Synthesis, Riga LV-1006, Latvia
| | - Edgars Liepins
- Latvian
Institute of Organic Synthesis, Riga LV-1006, Latvia
| | | | - Fiona Hackett
- Malaria
Biochemistry Laboratory, The Francis Crick
Institute, London NW1 1AT, United
Kingdom
| | - Christine R. Collins
- Malaria
Biochemistry Laboratory, The Francis Crick
Institute, London NW1 1AT, United
Kingdom
| | | | - María Belén Jiménez-Díaz
- The
Art of Discovery SL, Biscay Science and Technology Park, Derio, 48160 Bizkaia, Basque Country, Spain
| | - Iñigo Angulo-Barturen
- The
Art of Discovery SL, Biscay Science and Technology Park, Derio, 48160 Bizkaia, Basque Country, Spain
| | - Dace Rasina
- Latvian
Institute of Organic Synthesis, Riga LV-1006, Latvia
| | - Edgars Suna
- Latvian
Institute of Organic Synthesis, Riga LV-1006, Latvia
| | | | - Michael J. Blackman
- Malaria
Biochemistry Laboratory, The Francis Crick
Institute, London NW1 1AT, United
Kingdom
- Faculty
of Infectious and Tropical Diseases, London
School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
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10
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Lockyer EJ, Torelli F, Butterworth S, Song OR, Howell S, Weston A, East P, Treeck M. A heterotrimeric complex of Toxoplasma proteins promotes parasite survival in interferon gamma-stimulated human cells. PLoS Biol 2023; 21:e3002202. [PMID: 37459303 PMCID: PMC10373997 DOI: 10.1371/journal.pbio.3002202] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 07/27/2023] [Accepted: 06/16/2023] [Indexed: 07/28/2023] Open
Abstract
Toxoplasma gondii secretes protein effectors to subvert the human immune system sufficiently to establish a chronic infection. Relative to murine infections, little is known about which parasite effectors disarm human immune responses. Here, we used targeted CRISPR screening to identify secreted protein effectors required for parasite survival in IFNγ-activated human cells. Independent screens were carried out using 2 Toxoplasma strains that differ in virulence in mice, leading to the identification of effectors required for survival in IFNγ-activated human cells. We identify the secreted protein GRA57 and 2 other proteins, GRA70 and GRA71, that together form a complex which enhances the ability of parasites to persist in IFNγ-activated human foreskin fibroblasts (HFFs). Components of the protein machinery required for export of Toxoplasma proteins into the host cell were also found to be important for parasite resistance to IFNγ in human cells, but these export components function independently of the identified protein complex. Host-mediated ubiquitination of the parasite vacuole has previously been associated with increased parasite clearance from human cells, but we find that vacuoles from GRA57, GRA70, and GRA71 knockout strains are surprisingly less ubiquitinated by the host cell. We hypothesise that this is likely a secondary consequence of deletion of the complex, unlinked to the IFNγ resistance mediated by these effectors.
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Affiliation(s)
- Eloise J Lockyer
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Francesca Torelli
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Simon Butterworth
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ok-Ryul Song
- High-Throughput Screening Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Steven Howell
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Anne Weston
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Philip East
- Bioinformatics and Biostatistics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
- Cell Biology of Host-Pathogen Interaction Laboratory, Instituto Gulbenkian Ciência, Oeiras, Portugal
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11
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Ferreira JL, Pražák V, Vasishtan D, Siggel M, Hentzschel F, Binder AM, Pietsch E, Kosinski J, Frischknecht F, Gilberger TW, Grünewald K. Variable microtubule architecture in the malaria parasite. Nat Commun 2023; 14:1216. [PMID: 36869034 PMCID: PMC9984467 DOI: 10.1038/s41467-023-36627-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/09/2023] [Indexed: 03/05/2023] Open
Abstract
Microtubules are a ubiquitous eukaryotic cytoskeletal element typically consisting of 13 protofilaments arranged in a hollow cylinder. This arrangement is considered the canonical form and is adopted by most organisms, with rare exceptions. Here, we use in situ electron cryo-tomography and subvolume averaging to analyse the changing microtubule cytoskeleton of Plasmodium falciparum, the causative agent of malaria, throughout its life cycle. Unexpectedly, different parasite forms have distinct microtubule structures coordinated by unique organising centres. In merozoites, the most widely studied form, we observe canonical microtubules. In migrating mosquito forms, the 13 protofilament structure is further reinforced by interrupted luminal helices. Surprisingly, gametocytes contain a wide distribution of microtubule structures ranging from 13 to 18 protofilaments, doublets and triplets. Such a diversity of microtubule structures has not been observed in any other organism to date and is likely evidence of a distinct role in each life cycle form. This data provides a unique view into an unusual microtubule cytoskeleton of a relevant human pathogen.
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Affiliation(s)
- Josie L Ferreira
- Centre for Structural Systems Biology, Hamburg, Germany
- Leibniz Institute for Virology (LIV), Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London, UK
| | - Vojtěch Pražák
- Centre for Structural Systems Biology, Hamburg, Germany
- Leibniz Institute for Virology (LIV), Hamburg, Germany
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Daven Vasishtan
- Centre for Structural Systems Biology, Hamburg, Germany
- Leibniz Institute for Virology (LIV), Hamburg, Germany
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Marc Siggel
- Centre for Structural Systems Biology, Hamburg, Germany
- European Molecular Biology Laboratory, Hamburg, Germany
| | - Franziska Hentzschel
- Integrative Parasitology, Centre for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
- German Center for Infection Research, DZIF Partner Site Heidelberg, Heidelberg, Germany
| | - Annika M Binder
- Integrative Parasitology, Centre for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
| | - Emma Pietsch
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- University of Hamburg, Hamburg, Germany
| | - Jan Kosinski
- Centre for Structural Systems Biology, Hamburg, Germany
- European Molecular Biology Laboratory, Hamburg, Germany
- Structural and Computational Biology Unit, EMBL, Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Centre for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
- German Center for Infection Research, DZIF Partner Site Heidelberg, Heidelberg, Germany
| | - Tim W Gilberger
- Centre for Structural Systems Biology, Hamburg, Germany
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- University of Hamburg, Hamburg, Germany
| | - Kay Grünewald
- Centre for Structural Systems Biology, Hamburg, Germany.
- Leibniz Institute for Virology (LIV), Hamburg, Germany.
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK.
- University of Hamburg, Hamburg, Germany.
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12
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Rizk MA, El-Sayed SAES, El-Alfy ES, Igarashi I. Imidazo[1,2-a]pyridine: a Highly Potent Therapeutic Agent Clears Piroplasm Infection In Vitro. Acta Parasitol 2023; 68:249-256. [PMID: 36637693 DOI: 10.1007/s11686-022-00655-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 12/13/2022] [Indexed: 01/14/2023]
Abstract
BACKGROUND AND PURPOSE The imidazo[1,2-a] pyridines have huge applications in medicinal chemistry with potent activity against wide spectrum of infectious agents. The efficacy of imidazo[1,2-a]pyridine on the in vitro growth of different piroplasms, including Babesia bovis, B. bigemina, B. divergens, B. caballi, and Theileria equi, was investigated in this study. METHODS The anti-piroplasm efficacy of imidazo[1,2-a] pyridines was assessed using a fluorescence-based SYBR Green I assay. Furthermore, efficacy of imidazo[1,2-a]pyridine against piroplasms following discontinuation of treatment was also assessed using a viability assay. In vitro cultures of B. bovis and T. equi were used to assess the imidazo[1,2-a]pyridine and diminazene aceturate (DA) interaction. RESULTS In vitro, imidazo[1,2-a]pyridine inhibited the growth of B. bovis, B. bigemina, B. caballi, and T. equi in a dose-dependent manner. The highest inhibitory effects of imidazo[1,2-a]pyridine were detected on the growth of B. caballi with IC50 value of 0.47 ± 0.07. Interestingly, the efficacy of imidazo[1,2-a]pyridine was higher against B. bigemina (IC50: 1.37 ± 0.15) compared to the positive-control DA (IC50: 2.29 ± 0.06). The viability test findings indicate that imidazo[1,2-a]pyridine had a long-lasting inhibitory effect on bovine Babesia parasites in vitro growth up to 4 days after treatment. Notably, when coupled with DA at 0.75 or 0.50 IC50, a high concentration (0.75 IC50) of imidazo[1,2-a]pyridine produced additive suppression of B. bovis growth which suggest that imidazo[1,2-a]pyridine/DA could be a promising combination therapy for the treatment of B. bovis. CONCLUSION The obtained encouraging findings pave the way for in vitro and in vivo efficacy trials of imidazo[1,2-a]pyridine derivatives against several piroplasmids.
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Affiliation(s)
- Mohamed Abdo Rizk
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-Cho, Obihiro, Hokkaido, 080-8555, Japan. .,Department of Internal Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt.
| | - Shimaa Abd El-Salam El-Sayed
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-Cho, Obihiro, Hokkaido, 080-8555, Japan. .,Department of Biochemistry and Chemistry of Nutrition, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt.
| | - El-Sayed El-Alfy
- Parasitology Department, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - Ikuo Igarashi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-Cho, Obihiro, Hokkaido, 080-8555, Japan.
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13
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Elsworth B, Keroack C, Rezvani Y, Paul A, Barazorda K, Tennessen J, Sack S, Moreira C, Gubbels MJ, Meyers M, Zarringhalam K, Duraisingh M. Babesia divergens egress from host cells is orchestrated by essential and druggable kinases and proteases. RESEARCH SQUARE 2023:rs.3.rs-2553721. [PMID: 36909484 PMCID: PMC10002801 DOI: 10.21203/rs.3.rs-2553721/v1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Apicomplexan egress from host cells is fundamental to the spread of infection and is poorly characterized in Babesia spp., parasites of veterinary importance and emerging zoonoses. Through the use of video microscopy, transcriptomics and chemical genetics, we have implicated signaling, proteases and gliding motility as key drivers of egress by Babesia divergens. We developed reverse genetics to perform a knockdown screen of putative mediators of egress, identifying kinases and proteases involved in distinct steps of egress (ASP3, PKG and CDPK4) and invasion (ASP2, ASP3 and PKG). Inhibition of egress leads to continued intracellular replication, indicating exit from the replication cycle is uncoupled from egress. Chemical genetics validated PKG, ASP2 and ASP3 as druggable targets in Babesia spp. All taken together, egress in B. divergens more closely resembles T. gondii than the more evolutionarily-related Plasmodium spp. We have established a molecular framework for biological and translational studies of B. divergens egress.
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14
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Toxoplasma Shelph, a Phosphatase Located in the Parasite Endoplasmic Reticulum, Is Required for Parasite Virulence. mSphere 2022; 7:e0035022. [PMID: 36326242 PMCID: PMC9769683 DOI: 10.1128/msphere.00350-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Toxoplasma gondii is a single-celled parasitic eukaryote that evolved to successfully propagate in any nucleated cell. As with any other eukaryote, its life cycle is regulated by signaling pathways controlled by kinases and phosphatases. T. gondii encodes an atypical bacterial-like phosphatase absent from mammalian genomes, named Shelph, after its first identification in the psychrophilic bacterium Schewanella sp. Here, we demonstrate that Toxoplasma Shelph is an active phosphatase localized in the parasite endoplasmic reticulum. The phenotyping of a shelph knockout (KO) line showed a minor impairment in invasion on human fibroblasts, while the other steps of the parasite lytic cycle were not affected. In contrast with Plasmodium ortholog Shelph1, this invasion deficiency was not correlated with any default in the biogenesis of secretory organelles. However, Shelph-KO parasites displayed a much-pronounced defect in virulence in vivo. These phenotypes could be rescued by genetic complementation, thus supporting an important function for Shelph in the context of a natural infection. IMPORTANCE Toxoplasma gondii belongs to the Apicomplexa phylum, which comprises more than 5,000 species, among which is Plasmodium falciparum, the notorious agent of human malaria. Intriguingly, the Apicomplexa genomes encode at least one phosphatase closely related to the bacterial Schewanella phosphatase, or Shelph. To better understand the importance of these atypical bacterial enzymes in eukaryotic parasites, we undertook the functional characterization of T. gondii Shelph. Our results uncovered its subcellular localization and its enzymatic activity, revealed its subtle involvement during the tachyzoite invasion step of the lytic cycle, and more importantly, highlighted a critical requirement of this phosphatase for parasite propagation in mice. Overall, this study revealed an unexpected role for T. gondii Shelph in the maintenance of parasite virulence in vivo.
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15
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Abstract
Human malaria, caused by infection with Plasmodium parasites, remains one of the most important global public health problems, with the World Health Organization reporting more than 240 million cases and 600,000 deaths annually as of 2020 (World malaria report 2021). Our understanding of the biology of these parasites is critical for development of effective therapeutics and prophylactics, including both antimalarials and vaccines. Plasmodium is a protozoan organism that is intracellular for most of its life cycle. However, to complete its complex life cycle and to allow for both amplification and transmission, the parasite must egress out of the host cell in a highly regulated manner. This review discusses the major pathways and proteins involved in the egress events during the Plasmodium life cycle-merozoite and gametocyte egress out of red blood cells, sporozoite egress out of the oocyst, and merozoite egress out of the hepatocyte. The similarities, as well as the differences, between the various egress pathways of the parasite highlight both novel cell biology and potential therapeutic targets to arrest its life cycle.
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Affiliation(s)
- Jeffrey D Dvorin
- Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, USA;
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Daniel E Goldberg
- Division of Infectious Diseases, Department of Medicine; and Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA;
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16
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McDonald J, Merrick CJ. DNA replication dynamics during erythrocytic schizogony in the malaria parasites Plasmodium falciparum and Plasmodium knowlesi. PLoS Pathog 2022; 18:e1010595. [PMID: 35731838 PMCID: PMC9255763 DOI: 10.1371/journal.ppat.1010595] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 07/05/2022] [Accepted: 05/13/2022] [Indexed: 12/01/2022] Open
Abstract
Malaria parasites are unusual, early-diverging protozoans with non-canonical cell cycles. They do not undergo binary fission, but divide primarily by schizogony. This involves the asynchronous production of multiple nuclei within the same cytoplasm, culminating in a single mass cytokinesis event. The rate and efficiency of parasite reproduction is fundamentally important to malarial disease, which tends to be severe in hosts with high parasite loads. Here, we have studied for the first time the dynamics of schizogony in two human malaria parasite species, Plasmodium falciparum and Plasmodium knowlesi. These differ in their cell-cycle length, the number of progeny produced and the genome composition, among other factors. Comparing them could therefore yield new information about the parameters and limitations of schizogony. We report that the dynamics of schizogony differ significantly between these two species, most strikingly in the gap phases between successive nuclear multiplications, which are longer in P. falciparum and shorter, but more heterogenous, in P. knowlesi. In both species, gaps become longer as schizogony progresses, whereas each period of active DNA replication grows shorter. In both species there is also extreme variability between individual cells, with some schizonts producing many more nuclei than others, and some individual nuclei arresting their DNA replication for many hours while adjacent nuclei continue to replicate. The efficiency of schizogony is probably influenced by a complex set of factors in both the parasite and its host cell. Malaria parasites are unusual, early-diverging single-celled organisms. One of their atypical features is their mode of producing new cells. Most cells replicate their genome, segregate the copies into two nuclei and then split the whole cell in two: a process called binary fission. Malaria parasites, by contrast, multiply primarily by schizogony. Each cell replicates its genome several times over, asynchronously, generating many nuclei within the same cytoplasm, before splitting into many new daughter cells in a single mass event. All malaria species do this, but there are stark differences between species in how long schizogony takes and how many progeny each cell can produce. Understanding this is important because the rate of parasite reproduction is fundamentally important to malarial disease: humans who have a high burden of parasites in their blood are most likely to suffer severe malaria. Here we compare the process of schizogony in two different species, by developing cell lines in which we can follow de novo DNA replication at high spatial and temporal resolution, at both whole-cell and single-molecule levels. We establish the dynamics of schizogony, highlighting similarities and differences between two species and setting parameters for future studies of interventions that could interfere with parasite reproduction.
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Affiliation(s)
- Jennifer McDonald
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
| | - Catherine J. Merrick
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
- * E-mail:
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17
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Liang S, Zhao Q, Ye Y, Zhu S, Dong H, Yu Y, Huang B, Han H. Characteristics analyses of Eimeria tenella 14-3-3 protein and verification of its interaction with calcium-dependent protein kinase 4. Eur J Protistol 2022; 85:125895. [DOI: 10.1016/j.ejop.2022.125895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 04/23/2022] [Accepted: 05/11/2022] [Indexed: 11/27/2022]
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18
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Rinkenberger N, Abrams ME, Matta SK, Schoggins JW, Alto NM, Sibley LD. Over-expression screen of interferon-stimulated genes identifies RARRES3 as a restrictor of Toxoplasma gondii infection. eLife 2021; 10:73137. [PMID: 34871166 PMCID: PMC8789288 DOI: 10.7554/elife.73137] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/05/2021] [Indexed: 12/26/2022] Open
Abstract
Toxoplasma gondii is an important human pathogen infecting an estimated one in three people worldwide. The cytokine interferon gamma (IFNγ) is induced during infection and is critical for restricting T. gondii growth in human cells. Growth restriction is presumed to be due to the induction of interferon-stimulated genes (ISGs) that are upregulated to protect the host from infection. Although there are hundreds of ISGs induced by IFNγ, their individual roles in restricting parasite growth in human cells remain somewhat elusive. To address this deficiency, we screened a library of 414 IFNγ induced ISGs to identify factors that impact T. gondii infection in human cells. In addition to IRF1, which likely acts through the induction of numerous downstream genes, we identified RARRES3 as a single factor that restricts T. gondii infection by inducing premature egress of the parasite in multiple human cell lines. Overall, while we successfully identified a novel IFNγ induced factor restricting T. gondii infection, the limited number of ISGs capable of restricting T. gondii infection when individually expressed suggests that IFNγ-mediated immunity to T. gondii infection is a complex, multifactorial process.
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Affiliation(s)
- Nicholas Rinkenberger
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, United States
| | - Michael E Abrams
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Sumit K Matta
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, United States
| | - John W Schoggins
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Neal M Alto
- Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, United States
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19
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Alder A, Struck NS, Xu M, Johnson JW, Wang W, Pallant D, Cook MA, Rambow J, Lemcke S, Gilberger TW, Wright GD. A non-reactive natural product precursor of the duocarmycin family has potent and selective antimalarial activity. Cell Chem Biol 2021; 29:840-853.e6. [PMID: 34710358 DOI: 10.1016/j.chembiol.2021.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/15/2021] [Accepted: 10/02/2021] [Indexed: 11/27/2022]
Abstract
We identify a selective nanomolar inhibitor of blood-stage malarial proliferation from a screen of microbial natural product extracts. The responsible compound, PDE-I2, is a precursor of the anticancer duocarmycin family that preserves the class's sequence-specific DNA binding but lacks its signature DNA alkylating cyclopropyl warhead. While less active than duocarmycin, PDE-I2 retains comparable antimalarial potency to chloroquine. Importantly, PDE-I2 is >1,000-fold less toxic to human cell lines than duocarmycin, with mitigated impacts on eukaryotic chromosome stability. PDE-I2 treatment induces severe defects in parasite nuclear segregation leading to impaired daughter cell formation during schizogony. Time-of-addition studies implicate parasite DNA metabolism as the target of PDE-I2, with defects observed in DNA replication and chromosome integrity. We find the effect of duocarmycin and PDE-I2 on parasites is phenotypically indistinguishable, indicating that the DNA binding specificity of duocarmycins is sufficient and the genotoxic cyclopropyl warhead is dispensable for the parasite-specific selectivity of this compound class.
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Affiliation(s)
- Arne Alder
- Centre for Structural Systems Biology, 22607 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; University of Hamburg, Department of Biology, 20146 Hamburg, Germany
| | - Nicole S Struck
- Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada; German Centre for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Min Xu
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Jarrod W Johnson
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Wenliang Wang
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Daniel Pallant
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Michael A Cook
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Janis Rambow
- Centre for Structural Systems Biology, 22607 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; University of Hamburg, Department of Biology, 20146 Hamburg, Germany
| | - Sarah Lemcke
- Centre for Structural Systems Biology, 22607 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; University of Hamburg, Department of Biology, 20146 Hamburg, Germany
| | - Tim W Gilberger
- Centre for Structural Systems Biology, 22607 Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Department of Cellular Parasitology, 20359 Hamburg, Germany; University of Hamburg, Department of Biology, 20146 Hamburg, Germany.
| | - Gerard D Wright
- M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada.
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20
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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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21
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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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22
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Baker DA, Matralis AN, Osborne SA, Large JM, Penzo M. Targeting the Malaria Parasite cGMP-Dependent Protein Kinase to Develop New Drugs. Front Microbiol 2020; 11:602803. [PMID: 33391223 PMCID: PMC7773720 DOI: 10.3389/fmicb.2020.602803] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/23/2020] [Indexed: 12/17/2022] Open
Abstract
The single-celled apicomplexan parasite Plasmodium falciparum is responsible for the majority of deaths due to malaria each year. The selection of drug resistance has been a recurring theme over the decades with each new drug that is developed. It is therefore crucial that future generations of drugs are explored to tackle this major public health problem. Cyclic GMP (cGMP) signaling is one of the biochemical pathways that is being explored as a potential target for new antimalarial drugs. It has been shown that this pathway is essential for all of the key developmental stages of the complex malaria parasite life cycle. This gives hope that targeting cGMP signaling might give rise to drugs that treat disease, block its transmission and even prevent the establishment of infection. Here we review previous work that has been carried out to develop and optimize inhibitors of the cGMP-dependent protein kinase (PKG) which is a critical regulator of the malaria parasite life cycle.
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Affiliation(s)
- David A Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | - Simon A Osborne
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, United Kingdom
| | - Jonathan M Large
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, United Kingdom
| | - Maria Penzo
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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23
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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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24
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Souza Silva JA, Tunes LG, Coimbra RS, Ascher DB, Pires DEV, Monte-Neto RL. Unveiling six potent and highly selective antileishmanial agents via the open source compound collection 'Pathogen Box' against antimony-sensitive and -resistant Leishmania braziliensis. Biomed Pharmacother 2020; 133:111049. [PMID: 33378956 DOI: 10.1016/j.biopha.2020.111049] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/15/2020] [Accepted: 11/19/2020] [Indexed: 02/06/2023] Open
Abstract
Despite all efforts to provide new chemical entities to tackle leishmaniases, we are still dependent on a the limited drug arsenal, together with drawbacks like toxicity and drug-resistant parasites. Collaborative drug discovery emerged as an option to speed up the way to find alternative antileishmanial agents. This is the case of Medicines for Malaria Ventures - MMV, that promotes an open source drug discovery initiative to fight diseases worldwide. Here, we screened 400 compounds from 'Pathogen Box' (PBox) collection against Leishmania braziliensis, the main etiological agent of cutaneous leishmaniasis in Brazil. Twenty-three compounds were able to inhibit ≥ 80 % L. braziliensis growth at 5 μM. Six out of the PBox selected 23 compounds were found to be highly selective against L. braziliensis intracellular amastigotes with selectivity index varying from > 104 to > 746 and IC50s ranging from 47 to 480 nM. The compounds were also active against antimony-resistant L. braziliensis isolated from the field or laboratory selected mutants, revealing the potential on treating patients infected with drug resistant parasites. Most of the selected compounds were known to be active against kinetoplastids, however, two compounds (MMV688703 and MMV676477) were part of toxoplasmosis and tuberculosis 'PBox' disease set, reinforcing the potential of phenotyping screening to unveil drug repurposing. Here we applied a computational prediction of pharmacokinetic properties using the ADMET predictor pkCSM (http://biosig.unimelb.edu.au/pkcsm/). The tool offered clues on potential drug development needs and can support further in vivo studies. Molecular docking analysis identified CRK3 (LbrM.35.0660), CYP450 (LbrM.30.3580) and PKA (LbrM.18.1180) as L. braziliensis targets for MMV676604, MMV688372 and MMV688703, respectively. Compounds from 'Pathogen Box' thus represents a new hope for novel (or repurposed) small molecules source to tackle leishmaniases.
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Affiliation(s)
- Juliano A Souza Silva
- Instituto René Rachou - Fiocruz Minas, Av. Augusto de Lima, 1715, Belo Horizonte, 30190-009, MG, Brazil.
| | - Luiza G Tunes
- Instituto René Rachou - Fiocruz Minas, Av. Augusto de Lima, 1715, Belo Horizonte, 30190-009, MG, Brazil.
| | - Roney S Coimbra
- Instituto René Rachou - Fiocruz Minas, Av. Augusto de Lima, 1715, Belo Horizonte, 30190-009, MG, Brazil.
| | - David B Ascher
- Structural Biology and Bioinformatics, Department of Biochemistry and Molecular Biology, The University of Melbourne, Bio21 Institute, 30 Flemington Rd, Parkville, VIC 3052, Melbourne, Australia; Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, VIC 3004, Melbourne, Australia.
| | - Douglas E V Pires
- Instituto René Rachou - Fiocruz Minas, Av. Augusto de Lima, 1715, Belo Horizonte, 30190-009, MG, Brazil; School of Computing and Information Systems, The University of Melbourne, Doug McDonell Building, VIC 3010, Parkville, Melbourne, Australia.
| | - Rubens L Monte-Neto
- Instituto René Rachou - Fiocruz Minas, Av. Augusto de Lima, 1715, Belo Horizonte, 30190-009, MG, Brazil.
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25
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Abstract
Malaria is one of the most impacting public health problems in tropical and subtropical areas of the globe, with approximately 200 million cases worldwide annually. In the absence of an effective vaccine, rapid treatment is vital for effective malaria control. However, parasite resistance to currently available drugs underscores the urgent need for identifying new antimalarial therapies with new mechanisms of action. Among potential drug targets for developing new antimalarial candidates, protein kinases are attractive. These enzymes catalyze the phosphorylation of several proteins, thereby regulating a variety of cellular processes and playing crucial roles in the development of all stages of the malaria parasite life cycle. Moreover, the large phylogenetic distance between Plasmodium species and its human host is reflected in marked differences in structure and function of malaria protein kinases between the homologs of both species, indicating that selectivity can be attained. In this review, we describe the functions of the different types of Plasmodium kinases and highlight the main recent advances in the discovery of kinase inhibitors as potential new antimalarial drug candidates.
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26
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Ressurreição M, Thomas JA, Nofal SD, Flueck C, Moon RW, Baker DA, van Ooij C. Use of a highly specific kinase inhibitor for rapid, simple and precise synchronization of Plasmodium falciparum and Plasmodium knowlesi asexual blood-stage parasites. PLoS One 2020; 15:e0235798. [PMID: 32673324 PMCID: PMC7365400 DOI: 10.1371/journal.pone.0235798] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/22/2020] [Indexed: 12/15/2022] Open
Abstract
During the course of the asexual erythrocytic stage of development, Plasmodium spp. parasites undergo a series of morphological changes and induce alterations in the host cell. At the end of this stage, the parasites egress from the infected cell, after which the progeny invade a new host cell. These processes are rapid and occur in a time-dependent manner. Of particular importance, egress and invasion of erythrocytes by the parasite are difficult to capture in an unsynchronized culture, or even a culture that has been synchronized within a window of one to several hours. Therefore, precise synchronization of parasite cultures is of paramount importance for the investigation of these processes. Here we describe a method for synchronizing Plasmodium falciparum and Plasmodium knowlesi asexual blood stage parasites with ML10, a highly specific inhibitor of the cGMP-dependent protein kinase (PKG) that arrests parasite growth approximately 15 minutes prior to egress. This inhibitor allows parasite cultures to be synchronized so that all parasites are within a window of development of several minutes, with a simple wash step. Furthermore, we show that parasites remain viable for several hours after becoming arrested by the compound and that ML10 has advantages, owing to its high specificity and low EC50, over the previously used PKG inhibitor Compound 2. Here, we demonstrate that ML10 is an invaluable tool for the study of Plasmodium spp. asexual blood stage biology and for the routine synchronization of P. falciparum and P. knowlesi cultures.
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Affiliation(s)
- Margarida Ressurreição
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - James A. Thomas
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Stephanie D. Nofal
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christian Flueck
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Robert W. Moon
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David A. Baker
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christiaan van Ooij
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
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27
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Dantzler KW, Ma S, Ngotho P, Stone WJR, Tao D, Rijpma S, De Niz M, Nilsson Bark SK, Jore MM, Raaijmakers TK, Early AM, Ubaida-Mohien C, Lemgruber L, Campo JJ, Teng AA, Le TQ, Walker CL, Hermand P, Deterre P, Davies DH, Felgner P, Morlais I, Wirth DF, Neafsey DE, Dinglasan RR, Laufer M, Huttenhower C, Seydel K, Taylor T, Bousema T, Marti M. Naturally acquired immunity against immature Plasmodium falciparum gametocytes. Sci Transl Med 2020; 11:11/495/eaav3963. [PMID: 31167926 DOI: 10.1126/scitranslmed.aav3963] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 04/05/2019] [Indexed: 12/11/2022]
Abstract
The recent decline in global malaria burden has stimulated efforts toward Plasmodium falciparum elimination. Understanding the biology of malaria transmission stages may provide opportunities to reduce or prevent onward transmission to mosquitoes. Immature P. falciparum transmission stages, termed stages I to IV gametocytes, sequester in human bone marrow before release into the circulation as mature stage V gametocytes. This process likely involves interactions between host receptors and potentially immunogenic adhesins on the infected red blood cell (iRBC) surface. Here, we developed a flow cytometry assay to examine immune recognition of live gametocytes of different developmental stages by naturally exposed Malawians. We identified strong antibody recognition of the earliest immature gametocyte-iRBCs (giRBCs) but not mature stage V giRBCs. Candidate surface antigens (n = 30), most of them shared between asexual- and gametocyte-iRBCs, were identified by mass spectrometry and mouse immunizations, as well as correlations between responses by protein microarray and flow cytometry. Naturally acquired responses to a subset of candidate antigens were associated with reduced asexual and gametocyte density, and plasma samples from malaria-infected individuals were able to induce immune clearance of giRBCs in vitro. Infected RBC surface expression of select candidate antigens was validated using specific antibodies, and genetic analysis revealed a subset with minimal variation across strains. Our data demonstrate that humoral immune responses to immature giRBCs and shared iRBC antigens are naturally acquired after malaria exposure. These humoral immune responses may have consequences for malaria transmission potential by clearing developing gametocytes, which could be leveraged for malaria intervention.
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Affiliation(s)
- Kathleen W Dantzler
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Siyuan Ma
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Priscilla Ngotho
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Will J R Stone
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands.,Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Dingyin Tao
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and the Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Sanna Rijpma
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands
| | - Mariana De Niz
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Sandra K Nilsson Bark
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Matthijs M Jore
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands
| | - Tonke K Raaijmakers
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands
| | | | | | - Leandro Lemgruber
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | | | | | | | | | - Patricia Hermand
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), UMR 1135, ERL CNRS 8255, F-75013 Paris, France
| | - Philippe Deterre
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), UMR 1135, ERL CNRS 8255, F-75013 Paris, France
| | - D Huw Davies
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine, CA, USA
| | - Phil Felgner
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine, CA, USA
| | - Isabelle Morlais
- UMR MIVEGEC UM1-CNRS 5290-IRD 224, Institut de Recherche pour le Développement, Montpellier Cedex, France
| | - Dyann F Wirth
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Rhoel R Dinglasan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and the Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Emerging Pathogens Institute, Department of Infectious Diseases and Immunology, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
| | - Miriam Laufer
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Curtis Huttenhower
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Karl Seydel
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA.,Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Terrie Taylor
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA.,Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands. .,Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Matthias Marti
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA. .,Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
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28
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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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29
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Villalobo A, González-Muñoz M, Berchtold MW. Proteins with calmodulin-like domains: structures and functional roles. Cell Mol Life Sci 2019; 76:2299-2328. [PMID: 30877334 PMCID: PMC11105222 DOI: 10.1007/s00018-019-03062-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 02/26/2019] [Accepted: 03/07/2019] [Indexed: 12/21/2022]
Abstract
The appearance of modular proteins is a widespread phenomenon during the evolution of proteins. The combinatorial arrangement of different functional and/or structural domains within a single polypeptide chain yields a wide variety of activities and regulatory properties to the modular proteins. In this review, we will discuss proteins, that in addition to their catalytic, transport, structure, localization or adaptor functions, also have segments resembling the helix-loop-helix EF-hand motifs found in Ca2+-binding proteins, such as calmodulin (CaM). These segments are denoted CaM-like domains (CaM-LDs) and play a regulatory role, making these CaM-like proteins sensitive to Ca2+ transients within the cell, and hence are able to transduce the Ca2+ signal leading to specific cellular responses. Importantly, this arrangement allows to this group of proteins direct regulation independent of other Ca2+-sensitive sensor/transducer proteins, such as CaM. In addition, this review also covers CaM-binding proteins, in which their CaM-binding site (CBS), in the absence of CaM, is proposed to interact with other segments of the same protein denoted CaM-like binding site (CLBS). CLBS are important regulatory motifs, acting either by keeping these CaM-binding proteins inactive in the absence of CaM, enhancing the stability of protein complexes and/or facilitating their dimerization via CBS/CLBS interaction. The existence of proteins containing CaM-LDs or CLBSs substantially adds to the enormous versatility and complexity of Ca2+/CaM signaling.
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Affiliation(s)
- Antonio Villalobo
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Arturo Duperier 4, 28029, Madrid, Spain.
- Instituto de Investigaciones Sanitarias, Hospital Universitario La Paz, Edificio IdiPAZ, Paseo de la Castellana 261, 28046, Madrid, Spain.
| | - María González-Muñoz
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Arturo Duperier 4, 28029, Madrid, Spain
| | - Martin W Berchtold
- Department of Biology, University of Copenhagen, 13 Universitetsparken, 2100, Copenhagen, Denmark.
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30
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To kill a piroplasm: genetic technologies to advance drug discovery and target identification in Babesia. Int J Parasitol 2019; 49:153-163. [DOI: 10.1016/j.ijpara.2018.09.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 09/07/2018] [Accepted: 09/19/2018] [Indexed: 12/26/2022]
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31
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Tsagris DJ, Birchall K, Bouloc N, Large JM, Merritt A, Smiljanic-Hurley E, Wheldon M, Ansell KH, Kettleborough C, Whalley D, Stewart LB, Bowyer PW, Baker DA, Osborne SA. Trisubstituted thiazoles as potent and selective inhibitors of Plasmodium falciparum protein kinase G (PfPKG). Bioorg Med Chem Lett 2018; 28:3168-3173. [PMID: 30174152 DOI: 10.1016/j.bmcl.2018.08.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 01/28/2023]
Abstract
A series of trisubstituted thiazoles have been identified as potent inhibitors of Plasmodium falciparum (Pf) cGMP-dependent protein kinase (PfPKG) through template hopping from known Eimeria PKG (EtPKG) inhibitors. The thiazole series has yielded compounds with improved potency, kinase selectivity and good in vitro ADME properties. These compounds could be useful tools in the development of new anti-malarial drugs in the fight against drug resistant malaria.
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Affiliation(s)
- Denise J Tsagris
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK.
| | - Kristian Birchall
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | - Nathalie Bouloc
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | - Jonathan M Large
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | - Andy Merritt
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | | | - Mary Wheldon
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | - Keith H Ansell
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | | | - David Whalley
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | - Lindsay B Stewart
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Paul W Bowyer
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - David A Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Simon A Osborne
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
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32
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Baker DA, Drought LG, Flueck C, Nofal SD, Patel A, Penzo M, Walker EM. Cyclic nucleotide signalling in malaria parasites. Open Biol 2018; 7:rsob.170213. [PMID: 29263246 PMCID: PMC5746546 DOI: 10.1098/rsob.170213] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/28/2017] [Indexed: 12/22/2022] Open
Abstract
The cyclic nucleotides 3′, 5′-cyclic adenosine monophosphate (cAMP) and 3′, 5′-cyclic guanosine monophosphate (cGMP) are intracellular messengers found in most animal cell types. They usually mediate an extracellular stimulus to drive a change in cell function through activation of their respective cyclic nucleotide-dependent protein kinases, PKA and PKG. The enzymatic components of the malaria parasite cyclic nucleotide signalling pathways have been identified, and the genetic and biochemical studies of these enzymes carried out to date are reviewed herein. What has become very clear is that cyclic nucleotides play vital roles in controlling every stage of the complex malaria parasite life cycle. Our understanding of the involvement of cyclic nucleotide signalling in orchestrating the complex biology of malaria parasites is still in its infancy, but the recent advances in our genetic tools and the increasing interest in signalling will deliver more rapid progress in the coming years.
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Affiliation(s)
- David A Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Laura G Drought
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Christian Flueck
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Stephanie D Nofal
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Avnish Patel
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Maria Penzo
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.,Tres Cantos Medicines Development Campus, Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain
| | - Eloise M Walker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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33
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Jeffers V, Tampaki Z, Kim K, Sullivan WJ. A latent ability to persist: differentiation in Toxoplasma gondii. Cell Mol Life Sci 2018; 75:2355-2373. [PMID: 29602951 PMCID: PMC5988958 DOI: 10.1007/s00018-018-2808-x] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/01/2018] [Accepted: 03/26/2018] [Indexed: 01/08/2023]
Abstract
A critical factor in the transmission and pathogenesis of Toxoplasma gondii is the ability to convert from an acute disease-causing, proliferative stage (tachyzoite), to a chronic, dormant stage (bradyzoite). The conversion of the tachyzoite-containing parasitophorous vacuole membrane into the less permeable bradyzoite cyst wall allows the parasite to persist for years within the host to maximize transmissibility to both primary (felids) and secondary (virtually all other warm-blooded vertebrates) hosts. This review presents our current understanding of the latent stage, including the factors that are important in bradyzoite induction and maintenance. Also discussed are the recent studies that have begun to unravel the mechanisms behind stage switching.
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Affiliation(s)
- Victoria Jeffers
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
| | - Zoi Tampaki
- Departments of Medicine, Microbiology and Immunology, and Pathology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Kami Kim
- Departments of Medicine, Microbiology and Immunology, and Pathology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - William J Sullivan
- 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
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34
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Franz E, Knape MJ, Herberg FW. cGMP Binding Domain D Mediates a Unique Activation Mechanism in Plasmodium falciparum PKG. ACS Infect Dis 2018; 4:415-423. [PMID: 29251493 DOI: 10.1021/acsinfecdis.7b00222] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
cGMP-dependent protein kinase from Plasmodium falciparum ( PfPKG) plays a crucial role in the sexual as well as the asexual proliferation of this human malaria causing parasite. However, function and regulation of PfPKG are largely unknown. Previous studies showed that the domain organization of PfPKG significantly differs from human PKG ( hPKG) and indicated a critical role of the cyclic nucleotide binding domain D (CNB-D). We identified a novel mechanism, where the CNB-D controls activation and regulation of the parasite specific protein kinase. Here, kinase activity is not dependent on a pseudosubstrate autoinhibitory sequence (IS), as reported for human PKG. A construct lacking the putative IS and containing only the CNB-D and the catalytic domain is inactive in the absence of cGMP and can efficiently be activated with cGMP. On the basis of structural evidence, we describe a regulatory mechanism, whereby cGMP binding to CNB-D induces a conformational change involving the αC-helix of the CNB-D. The inactive state is defined by a unique interaction between Asp597 of the catalytic domain and Arg528 of the αC-helix. The same arginine (R528), however, stabilizes cGMP binding by interacting with Tyr480 of the phosphate binding cassette (PBC). This represents the active state of PfPKG. Our results unveil fundamental differences in the activation mechanism between PfPKG and hPKG, building the basis for the development of strategies for targeted drug design in fighting malaria.
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Affiliation(s)
- Eugen Franz
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
| | - Matthias J. Knape
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
| | - Friedrich W. Herberg
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
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Jia Y, Marq JB, Bisio H, Jacot D, Mueller C, Yu L, Choudhary J, Brochet M, Soldati-Favre D. Crosstalk between PKA and PKG controls pH-dependent host cell egress of Toxoplasma gondii. EMBO J 2017; 36:3250-3267. [PMID: 29030485 PMCID: PMC5666616 DOI: 10.15252/embj.201796794] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 09/08/2017] [Accepted: 09/12/2017] [Indexed: 12/27/2022] Open
Abstract
Toxoplasma gondii encodes three protein kinase A catalytic (PKAc1-3) and one regulatory (PKAr) subunits to integrate cAMP-dependent signals. Here, we show that inactive PKAc1 is maintained at the parasite pellicle by interacting with acylated PKAr. Either a conditional knockdown of PKAr or the overexpression of PKAc1 blocks parasite division. Conversely, down-regulation of PKAc1 or stabilisation of a dominant-negative PKAr isoform that does not bind cAMP triggers premature parasite egress from infected cells followed by serial invasion attempts leading to host cell lysis. This untimely egress depends on host cell acidification. A phosphoproteome analysis suggested the interplay between cAMP and cGMP signalling as PKAc1 inactivation changes the phosphorylation profile of a putative cGMP-phosphodiesterase. Concordantly, inhibition of the cGMP-dependent protein kinase G (PKG) blocks egress induced by PKAc1 inactivation or environmental acidification, while a cGMP-phosphodiesterase inhibitor circumvents egress repression by PKAc1 or pH neutralisation. This indicates that pH and PKAc1 act as balancing regulators of cGMP metabolism to control egress. These results reveal a crosstalk between PKA and PKG pathways to govern egress in T. gondii.
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Affiliation(s)
- Yonggen Jia
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva 4, Switzerland
| | - Jean-Baptiste Marq
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva 4, Switzerland
| | - Hugo Bisio
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva 4, Switzerland
| | - Damien Jacot
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva 4, Switzerland
| | - Christina Mueller
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva 4, Switzerland
| | - Lu Yu
- Proteomic Mass-spectrometry Team, Wellcome Trust Sanger Institute, Hinxton, UK
| | - Jyoti Choudhary
- Proteomic Mass-spectrometry Team, Wellcome Trust Sanger Institute, Hinxton, UK
| | - Mathieu Brochet
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva 4, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva 4, Switzerland
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Baker DA, Stewart LB, Large JM, Bowyer PW, Ansell KH, Jiménez-Díaz MB, El Bakkouri M, Birchall K, Dechering KJ, Bouloc NS, Coombs PJ, Whalley D, Harding DJ, Smiljanic-Hurley E, Wheldon MC, Walker EM, Dessens JT, Lafuente MJ, Sanz LM, Gamo FJ, Ferrer SB, Hui R, Bousema T, Angulo-Barturén I, Merritt AT, Croft SL, Gutteridge WE, Kettleborough CA, Osborne SA. A potent series targeting the malarial cGMP-dependent protein kinase clears infection and blocks transmission. Nat Commun 2017; 8:430. [PMID: 28874661 PMCID: PMC5585294 DOI: 10.1038/s41467-017-00572-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 07/10/2017] [Indexed: 01/08/2023] Open
Abstract
To combat drug resistance, new chemical entities are urgently required for use in next generation anti-malarial combinations. We report here the results of a medicinal chemistry programme focused on an imidazopyridine series targeting the Plasmodium falciparum cyclic GMP-dependent protein kinase (PfPKG). The most potent compound (ML10) has an IC50 of 160 pM in a PfPKG kinase assay and inhibits P. falciparum blood stage proliferation in vitro with an EC50 of 2.1 nM. Oral dosing renders blood stage parasitaemia undetectable in vivo using a P. falciparum SCID mouse model. The series targets both merozoite egress and erythrocyte invasion, but crucially, also blocks transmission of mature P. falciparum gametocytes to Anopheles stephensi mosquitoes. A co-crystal structure of PvPKG bound to ML10, reveals intimate molecular contacts that explain the high levels of potency and selectivity we have measured. The properties of this series warrant consideration for further development to produce an antimalarial drug. Protein kinases are promising drug targets for treatment of malaria. Here, starting with a medicinal chemistry approach, Baker et al. generate an imidazopyridine that selectively targets Plasmodium falciparum PKG, inhibits blood stage parasite growth in vitro and in mice and blocks transmission to mosquitoes.
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Affiliation(s)
- David A Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Lindsay B Stewart
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Jonathan M Large
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Paul W Bowyer
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Keith H Ansell
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - María B Jiménez-Díaz
- Tres Cantos Medicines Development Campus-Diseases of the Developing World, GlaxoSmithKline, Tres Cantos,, 28760, Madrid, Spain
| | - Majida El Bakkouri
- Structural Genomics Consortium, University of Toronto, MaRS South Tower, 101 College Street, Toronto, ON, Canada, M5G 1L7.,Toronto General Hospital Research Institute, 610 University Avenue, Toronto, ON, Canada, M5G 2M9
| | - Kristian Birchall
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Koen J Dechering
- TropIQ Health Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Nathalie S Bouloc
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Peter J Coombs
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - David Whalley
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Denise J Harding
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | | | - Mary C Wheldon
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Eloise M Walker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Johannes T Dessens
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - María José Lafuente
- Tres Cantos Medicines Development Campus-Diseases of the Developing World, GlaxoSmithKline, Tres Cantos,, 28760, Madrid, Spain
| | - Laura M Sanz
- Tres Cantos Medicines Development Campus-Diseases of the Developing World, GlaxoSmithKline, Tres Cantos,, 28760, Madrid, Spain
| | - Francisco-Javier Gamo
- Tres Cantos Medicines Development Campus-Diseases of the Developing World, GlaxoSmithKline, Tres Cantos,, 28760, Madrid, Spain
| | - Santiago B Ferrer
- Tres Cantos Medicines Development Campus-Diseases of the Developing World, GlaxoSmithKline, Tres Cantos,, 28760, Madrid, Spain
| | - Raymond Hui
- Structural Genomics Consortium, University of Toronto, MaRS South Tower, 101 College Street, Toronto, ON, Canada, M5G 1L7.,Toronto General Hospital Research Institute, 610 University Avenue, Toronto, ON, Canada, M5G 2M9
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, 6525 HP, Nijmegen, The Netherlands
| | - Iñigo Angulo-Barturén
- Tres Cantos Medicines Development Campus-Diseases of the Developing World, GlaxoSmithKline, Tres Cantos,, 28760, Madrid, Spain
| | - Andy T Merritt
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Simon L Croft
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Winston E Gutteridge
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | | | - Simon A Osborne
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
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37
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Abstract
Cyclic GMP (cGMP)-dependent protein kinase (protein kinase G [PKG]) is essential for microneme secretion, motility, invasion, and egress in apicomplexan parasites, However, the separate roles of two isoforms of the kinase that are expressed by some apicomplexans remain uncertain. Despite having identical regulatory and catalytic domains, PKGI is plasma membrane associated whereas PKGII is cytosolic in Toxoplasma gondii. To determine whether these isoforms are functionally distinct or redundant, we developed an auxin-inducible degron (AID) tagging system for conditional protein depletion in T. gondii. By combining AID regulation with genome editing strategies, we determined that PKGI is necessary and fully sufficient for PKG-dependent cellular processes. Conversely, PKGII is functionally insufficient and dispensable in the presence of PKGI. The difference in functionality mapped to the first 15 residues of PKGI, containing a myristoylated Gly residue at position 2 that is critical for membrane association and PKG function. Collectively, we have identified a novel requirement for cGMP signaling at the plasma membrane and developed a new system for examining essential proteins in T. gondii. Toxoplasma gondii is an obligate intracellular apicomplexan parasite and important clinical and veterinary pathogen that causes toxoplasmosis. Since apicomplexans can only propagate within host cells, efficient invasion is critically important for their life cycles. Previous studies using chemical genetics demonstrated that cyclic GMP signaling through protein kinase G (PKG)-controlled invasion by apicomplexan parasites. However, these studies did not resolve functional differences between two compartmentalized isoforms of the kinase. Here we developed a conditional protein regulation tool to interrogate PKG isoforms in T. gondii. We found that the cytosolic PKG isoform was largely insufficient and dispensable. In contrast, the plasma membrane-associated isoform was necessary and fully sufficient for PKG function. Our studies identify the plasma membrane as a key location for PKG activity and provide a broadly applicable system for examining essential proteins in T. gondii.
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38
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Stewart RJ, Whitehead L, Nijagal B, Sleebs BE, Lessene G, McConville MJ, Rogers KL, Tonkin CJ. Analysis of Ca 2+ mediated signaling regulating Toxoplasma infectivity reveals complex relationships between key molecules. Cell Microbiol 2017; 19. [PMID: 27781359 DOI: 10.1111/cmi.12685] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 10/14/2016] [Indexed: 12/28/2022]
Abstract
Host cell invasion, exit and parasite dissemination is critical to the pathogenesis of apicomplexan parasites such as Toxoplasma gondii and Plasmodium spp. These processes are regulated by intracellular Ca2+ signaling although the temporal dynamics of Ca2+ fluxes and down-stream second messenger pathways are poorly understood. Here, we use a genetically encoded biosensor, GFP-Calmodulin-M13-6 (GCaMP6), to capture Ca2+ flux in live Toxoplasma and investigate the role of Ca2+ signaling in egress and motility. Our analysis determines how environmental cues and signal activation influence intracellular Ca2+ flux, allowing placement of effector molecules within this pathway. Importantly, we have identified key interrelationships between cGMP and Ca2+ signaling that are required for activation of egress and motility. Furthermore, we extend this analysis to show that the Ca2+ Dependent Protein Kinases-TgCDPK1 and TgCDPK3-play a role in signal quenching before egress. This work highlights the interrelationships of second messenger pathways of Toxoplasma in space and time, which is likely required for pathogenesis of all apicomplexan species.
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Affiliation(s)
- Rebecca J Stewart
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Lachlan Whitehead
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Brunda Nijagal
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Brad E Sleebs
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Guillaume Lessene
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia.,Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Victoria, Australia
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Australia
| | - Kelly L Rogers
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Christopher J Tonkin
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
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39
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Wang Z, Huang B, Dong H, Zhao Q, Zhu S, Xia W, Xu S, Xie Y, Cui X, Tang M, Men Q, Yang Z, Li C, Zhu X, Han H. Molecular Characterization and Functional Analysis of a Novel Calcium-Dependent Protein Kinase 4 from Eimeria tenella. PLoS One 2016; 11:e0168132. [PMID: 27977727 PMCID: PMC5158193 DOI: 10.1371/journal.pone.0168132] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 11/26/2016] [Indexed: 11/19/2022] Open
Abstract
Eimeria tenella is an obligate intracellular parasite that actively invades cecal epithelial cells of chickens. The basis of cell invasion is not completely understood, but some key molecules of host cell invasion have been discovered. This paper investigated the characteristics of calcium-dependent protein kinase 4 (EtCDPK4), a critical molecule in E. tenella invasion of host cells. A full-length EtCDPK4 cDNA was identified from E. tenella using rapid amplification of cDNA ends. EtCDPK4 had an open reading frame of 1803 bp encoding a protein of 600 amino acids. Quantitative real-time PCR and western blotting were used to explore differences in EtCDPK4 transcription and translation in four developmental stages of E. tenella. EtCDPK4 was expressed at higher levels in sporozoites, but translation was higher in second-generation merozoites. In vitro invasion inhibition assays explored whether EtCDPK4 was involved in invasion of DF-1 cells by E. tenella sporozoites. Polyclonal antibodies against recombinant EtCDPK4 (rEtCDPK4) inhibited parasite invasion, decreasing it by approximately 52%. Indirect immunofluorescence assays explored EtCDPK4 distribution during parasite development after E. tenella sporozoite invasion of DF-1 cells in vitro. The results showed that EtCDPK4 might be important in sporozoite invasion and development. To analyze EtCDPK4 functional domains according to the structural characteristics of EtCDPK4 and study the kinase activity of rEtCDPK4, an in vitro phosphorylation system was established. We verified that rEtCDPK4 was a protein kinase that was completely dependent on Ca2+ for enzyme activity. Specific inhibitors of rEtCDPK4 activity were screened by kinase activity in vitro. Some specific inhibitors were applied to assays of DF-1 cell invasion by E. tenella sporozoites to confirm that the inhibitors functioned in vitro. W-7, H-7, H-89, and myristoylated peptide inhibited DF-1 invasion by E. tenella sporozoites. The experimental results showed that EtCDPK4 may be involved in E. tenella invasion of chicken cecal epithelial cells.
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Affiliation(s)
- Ziwen Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Bing Huang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, PR China
| | - Hui Dong
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Qiping Zhao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Shunhai Zhu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Weili Xia
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Shuaibin Xu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Yuxiang Xie
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Xiaoxia Cui
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Min Tang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Qifei Men
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Zhiyuang Yang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Cong Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Xuelong Zhu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
| | - Hongyu Han
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Minhang, Shanghai, PR China
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Targeted disruption of CK1α in Toxoplasma gondii increases acute virulence in mice. Eur J Protistol 2016; 56:90-101. [PMID: 27567091 DOI: 10.1016/j.ejop.2016.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 07/18/2016] [Accepted: 07/18/2016] [Indexed: 01/02/2023]
Abstract
Toxoplasma gondii, the causative agent of toxoplasmosis, encodes two casein kinase 1 (CK1) isoforms, CK1α and CK1β, with only CK1α having enzyme activity. Here we investigated the biological role of CK1α by construction of a CK1α deletion mutant (Δck1α) based on the type I parasite, and complement the mutant with restored expression of CK1α. Deletion of CK1α resulted in markedly defective parasite replication in vitro. Infected mice with Δck1α parasite caused suppression of IL-12 production, severe liver damage, higher tissue burdens, and short survival time relative to the CK1α-positive parental strain. Western blot analysis revealed that deletion of CK1α led to increased activation of the signal transducer and activator of transcription (STAT)-3 in infected mice and bone marrow-derived microphages. The transcriptome analysis showed that deletion of CK1α may increase expression of rhoptry proteins (ROPs). Western blot showed enhanced expression of ROP16 in the Δck1α parasite as compared with the wild-type and complemented parasites. These findings demonstrated that deletion of CK1α may increase acute virulence of T. gondii in mice by increased expression of ROPs, activation of STAT3, and suppression of IL-12 production, which have important implications for elucidating regulation mechanism of virulence factors for T. gondii.
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Kato K, Sugi T, Takemae H, Takano R, Gong H, Ishiwa A, Horimoto T, Akashi H. Characterization of a Toxoplasma gondii calcium calmodulin-dependent protein kinase homolog. Parasit Vectors 2016; 9:405. [PMID: 27444499 PMCID: PMC4957278 DOI: 10.1186/s13071-016-1676-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 06/30/2016] [Indexed: 12/04/2022] Open
Abstract
Background Toxoplasma gondii is an obligate intracellular parasite of the phylum Apicomplexa and a major pathogen of animals and immunocompromised humans, in whom it causes encephalitis. Understanding the mechanism of tachyzoite invasion is important for the discovery of new drug targets and may serve as a model for the study of other apicomplexan parasites. We previously showed that Plasmodium falciparum expresses a homolog of human calcium calmodulin-dependent protein kinase (CaMK) that is important for host cell invasion. In this study, to identify novel targets for the treatment of Toxoplasma gondii infection (another apicomplexan parasite), we sought to identify a CaMK-like protein in the T. gondii genome and to characterize its role in the life-cycle of this parasite. Methods An in vitro kinase assay was performed to assess the phosphorylation activities of a novel CaMK-like protein in T. gondii by using purified proteins with various concentrations of calcium, calmodulin antagonists, or T. gondii glideosome proteins. Indirect immunofluorescence microscopy was performed to detect the localization of this protein kinase by using the antibodies against this protein and organellar maker proteins of T. gondii. Results We identified a novel CaMK homolog in T. gondii, T. gondii CaMK-related kinase (TgCaMKrk), which exhibits calmodulin-independent autophosphorylation and substrate phosphorylation activity. However, calmodulin antagonists had no effect on its kinase activity. In T. gondii-infected cells, TgCaMKrk localized to the apical ends of extracellular and intracellular tachyzoites. TgCaMKrk phosphorylated TgGAP45 for phosphorylation in vitro. Conclusions Our data improve our understanding of T. gondii motility and infection, the interaction between parasite protein kinases and glideosomes, and drug targets for protozoan diseases.
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Affiliation(s)
- Kentaro Kato
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan. .,Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
| | - Tatsuki Sugi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.,Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Hitoshi Takemae
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.,Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Ryo Takano
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan
| | - Haiyan Gong
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Akiko Ishiwa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.,Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Taisuke Horimoto
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Hiroomi Akashi
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
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Sidik SM, Hortua Triana MA, Paul AS, El Bakkouri M, Hackett CG, Tran F, Westwood NJ, Hui R, Zuercher WJ, Duraisingh MT, Moreno SNJ, Lourido S. Using a Genetically Encoded Sensor to Identify Inhibitors of Toxoplasma gondii Ca2+ Signaling. J Biol Chem 2016; 291:9566-80. [PMID: 26933036 PMCID: PMC4850295 DOI: 10.1074/jbc.m115.703546] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Indexed: 11/27/2022] Open
Abstract
The life cycles of apicomplexan parasites progress in accordance with fluxes in cytosolic Ca2+. Such fluxes are necessary for events like motility and egress from host cells. We used genetically encoded Ca2+ indicators (GCaMPs) to develop a cell-based phenotypic screen for compounds that modulate Ca2+ signaling in the model apicomplexan Toxoplasma gondii. In doing so, we took advantage of the phosphodiesterase inhibitor zaprinast, which we show acts in part through cGMP-dependent protein kinase (protein kinase G; PKG) to raise levels of cytosolic Ca2+. We define the pool of Ca2+ regulated by PKG to be a neutral store distinct from the endoplasmic reticulum. Screening a library of 823 ATP mimetics, we identify both inhibitors and enhancers of Ca2+ signaling. Two such compounds constitute novel PKG inhibitors and prevent zaprinast from increasing cytosolic Ca2+. The enhancers identified are capable of releasing intracellular Ca2+ stores independently of zaprinast or PKG. One of these enhancers blocks parasite egress and invasion and shows strong antiparasitic activity against T. gondii. The same compound inhibits invasion of the most lethal malaria parasite, Plasmodium falciparum. Inhibition of Ca2+-related phenotypes in these two apicomplexan parasites suggests that depletion of intracellular Ca2+ stores by the enhancer may be an effective antiparasitic strategy. These results establish a powerful new strategy for identifying compounds that modulate the essential parasite signaling pathways regulated by Ca2+, underscoring the importance of these pathways and the therapeutic potential of their inhibition.
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Affiliation(s)
- Saima M Sidik
- From the Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142
| | - Miryam A Hortua Triana
- the Center for Tropical and Emerging Global Diseases, Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Aditya S Paul
- the Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Majida El Bakkouri
- the Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Caroline G Hackett
- From the Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142
| | - Fanny Tran
- the School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, North Haugh, St. Andrews, Fife KY16 9ST, Scotland, United Kingdom, and
| | - Nicholas J Westwood
- the School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, North Haugh, St. Andrews, Fife KY16 9ST, Scotland, United Kingdom, and
| | - Raymond Hui
- the Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - William J Zuercher
- the Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Manoj T Duraisingh
- the Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Silvia N J Moreno
- the Center for Tropical and Emerging Global Diseases, Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Sebastian Lourido
- From the Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142,
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Brown KM, Lourido S, Sibley LD. Serum Albumin Stimulates Protein Kinase G-dependent Microneme Secretion in Toxoplasma gondii. J Biol Chem 2016; 291:9554-65. [PMID: 26933037 DOI: 10.1074/jbc.m115.700518] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Indexed: 11/06/2022] Open
Abstract
Microneme secretion is essential for motility, invasion, and egress in apicomplexan parasites. Although previous studies indicate that Ca(2+) and cGMP control microneme secretion, little is known about how these pathways are naturally activated. Here we have developed genetically encoded indicators for Ca(2+) and microneme secretion to better define the signaling pathways that regulate these processes in Toxoplasma gondii We found that microneme secretion was triggered in vitro by exposure to a single host protein, serum albumin. The natural agonist serum albumin induced microneme secretion in a protein kinase G-dependent manner that correlated with increased cGMP levels. Surprisingly, serum albumin acted independently of elevated Ca(2+) and yet it was augmented by artificial agonists that raise Ca(2+), such as ethanol. Furthermore, although ethanol elevated intracellular Ca(2+), it alone was unable to trigger secretion without the presence of serum or serum albumin. This dichotomy was recapitulated by zaprinast, a phosphodiesterase inhibitor that elevated cGMP and separately increased Ca(2+) in a protein kinase G-independent manner leading to microneme secretion. Taken together, these findings reveal that microneme secretion is centrally controlled by protein kinase G and that this pathway is further augmented by elevation of intracellular Ca(2.)
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Affiliation(s)
- Kevin M Brown
- From the Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Sebastian Lourido
- From the Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - L David Sibley
- From the Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
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44
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Graindorge A, Frénal K, Jacot D, Salamun J, Marq JB, Soldati-Favre D. The Conoid Associated Motor MyoH Is Indispensable for Toxoplasma gondii Entry and Exit from Host Cells. PLoS Pathog 2016; 12:e1005388. [PMID: 26760042 PMCID: PMC4711953 DOI: 10.1371/journal.ppat.1005388] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 12/17/2015] [Indexed: 11/23/2022] Open
Abstract
Many members of the phylum of Apicomplexa have adopted an obligate intracellular life style and critically depend on active invasion and egress from the infected cells to complete their lytic cycle. Toxoplasma gondii belongs to the coccidian subgroup of the Apicomplexa, and as such, the invasive tachyzoite contains an organelle termed the conoid at its extreme apex. This motile organelle consists of a unique polymer of tubulin fibres and protrudes in both gliding and invading parasites. The class XIV myosin A, which is conserved across the Apicomplexa phylum, is known to critically contribute to motility, invasion and egress from infected cells. The MyoA-glideosome is anchored to the inner membrane complex (IMC) and is assumed to translocate the components of the circular junction secreted by the micronemes and rhoptries, to the rear of the parasite. Here we comprehensively characterise the class XIV myosin H (MyoH) and its associated light chains. We show that the 3 alpha-tubulin suppressor domains, located in MyoH tail, are necessary to anchor this motor to the conoid. Despite the presence of an intact MyoA-glideosome, conditional disruption of TgMyoH severely compromises parasite motility, invasion and egress from infected cells. We demonstrate that MyoH is necessary for the translocation of the circular junction from the tip of the parasite, where secretory organelles exocytosis occurs, to the apical position where the IMC starts. This study attributes for the first time a direct function of the conoid in motility and invasion, and establishes the indispensable role of MyoH in initiating the first step of motility along this unique organelle, which is subsequently relayed by MyoA to enact effective gliding and invasion. The Apicomplexa phylum groups important pathogens that infect humans and animals. Host cell invasion and egress from infected cells are key events in the lytic cycle of these obligate intracellular parasites. Host cell entry is powered by gliding motility and initiated by the discharge of apical secretory organelles at the site of contact with the host cell. Anchored to the parasite pellicle, the glideosome composed of myosin A and the gliding associated proteins is the molecular machine which translocates the secreted adhesins from the apical to the posterior pole of the parasite and hence propels the parasite into the host cell. Toxoplasma gondii exhibits a helical form of gliding motility and as member of the coccidian-subgroup of Apicomplexa possesses an apical organelle called the conoid, which protrudes during invasion and egress and consists in helically organized polymer of tubulin fibers. We have deciphered here the function of a novel myosin associated to the microtubules composing the conoid. Myosin H is essential and prerequisite for motility, invasion and egress from infected cells. This unusual motor links actin- and tubulin-based cytoskeletons and uncovers a direct role of the conoid in motility and invasion.
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Affiliation(s)
- Arnault Graindorge
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Karine Frénal
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Damien Jacot
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Julien Salamun
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Jean Baptiste Marq
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- * E-mail:
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45
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Shrestha A, Abd-Elfattah A, Freudenschuss B, Hinney B, Palmieri N, Ruttkowski B, Joachim A. Cystoisospora suis - A Model of Mammalian Cystoisosporosis. Front Vet Sci 2015; 2:68. [PMID: 26664994 PMCID: PMC4672278 DOI: 10.3389/fvets.2015.00068] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/17/2015] [Indexed: 11/13/2022] Open
Abstract
Cystoisospora suis is a coccidian species that typically affects suckling piglets. Infections occur by oral uptake of oocysts and are characterized by non-hemorrhagic transient diarrhea, resulting in poor weight gain. Apparently, primary immune responses to C. suis cannot readily be mounted by neonates, which contributes to the establishment and rapid development of the parasite, while in older pigs age-resistance prevents disease development. However, the presence of extraintestinal stages, although not unequivocally demonstrated, is suspected to enable parasite persistence together with the induction and maintenance of immune response in older pigs, which in turn may facilitate the transfer of C. suis-specific factors from sow to offspring. It is assumed that neonates are particularly prone to clinical disease because infections with C. suis interfere with the establishment of the gut microbiome. Clostridia have been especially inferred to profit from the altered intestinal environment during parasite infection. New tools, particularly in the area of genomics, might illustrate the interactions between C. suis and its host and pave the way for the development of new control methods not only for porcine cystoisosporosis but also for other mammalian Cystoisospora infections. The first reference genome for C. suis is under way and will be a fertile ground to discover new drugs and vaccines. At the same time, the establishment and refinement of an in vivo model and an in vitro culture system, supporting the complete life cycle of C. suis, will underpin the functional characterization of the parasite and shed light on its biology and control.
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Affiliation(s)
- Aruna Shrestha
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna , Vienna , Austria
| | - Ahmed Abd-Elfattah
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna , Vienna , Austria
| | - Barbara Freudenschuss
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna , Vienna , Austria
| | - Barbara Hinney
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna , Vienna , Austria
| | - Nicola Palmieri
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna , Vienna , Austria
| | - Bärbel Ruttkowski
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna , Vienna , Austria
| | - Anja Joachim
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna , Vienna , Austria
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46
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Inhibition of Calcium-Dependent Protein Kinase 1 (CDPK1) In Vitro by Pyrazolopyrimidine Derivatives Does Not Correlate with Sensitivity of Cryptosporidium parvum Growth in Cell Culture. Antimicrob Agents Chemother 2015; 60:570-9. [PMID: 26552986 DOI: 10.1128/aac.01915-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 11/06/2015] [Indexed: 11/20/2022] Open
Abstract
Cryptosporidiosis is a serious diarrheal disease in immunocompromised patients and malnourished children, and treatment is complicated by a lack of adequate drugs. Recent studies suggest that the natural occurrence of a small gatekeeper residue in serine threonine calcium-dependent protein kinase 1 (CDPK1) of Cryptosporidium parvum might be exploited to target this enzyme and block parasite growth. Here were explored the potency with which a series of pyrazolopyrimidine analogs, which are selective for small gatekeeper kinases, inhibit C. parvum CDPK1 and block C. parvum growth in tissue culture in vitro. Although these compounds potently inhibited kinase activity in vitro, most had no effect on parasite growth. Moreover, among those that were active against parasite growth, there was a very poor correlation with their 50% inhibitory concentrations against the enzyme. Active compounds also had no effect on cell invasion, unlike the situation in Toxoplasma gondii, where these compounds block CDPK1, prevent microneme secretion, and disrupt cell invasion. These findings suggest that CPDK1 is not essential for C. parvum host cell invasion or growth and therefore that it is not the optimal target for therapeutic intervention. Nonetheless, several inhibitors with low micromolar 50% effective concentrations were identified, and these may affect other essential targets in C. parvum that are worthy of further exploration.
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47
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Gaji RY, Johnson DE, Treeck M, Wang M, Hudmon A, Arrizabalaga G. Phosphorylation of a Myosin Motor by TgCDPK3 Facilitates Rapid Initiation of Motility during Toxoplasma gondii egress. PLoS Pathog 2015; 11:e1005268. [PMID: 26544049 PMCID: PMC4636360 DOI: 10.1371/journal.ppat.1005268] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 10/20/2015] [Indexed: 12/20/2022] Open
Abstract
Members of the family of calcium dependent protein kinases (CDPK’s) are abundant in certain pathogenic parasites and absent in mammalian cells making them strong drug target candidates. In the obligate intracellular parasite Toxoplasma gondii TgCDPK3 is important for calcium dependent egress from the host cell. Nonetheless, the specific substrate through which TgCDPK3 exerts its function during egress remains unknown. To close this knowledge gap we applied the proximity-based protein interaction trap BioID and identified 13 proteins that are either near neighbors or direct interactors of TgCDPK3. Among these was Myosin A (TgMyoA), the unconventional motor protein greatly responsible for driving the gliding motility of this parasite, and whose phosphorylation at serine 21 by an unknown kinase was previously shown to be important for motility and egress. Through a non-biased peptide array approach we determined that TgCDPK3 can specifically phosphorylate serines 21 and 743 of TgMyoA in vitro. Complementation of the TgmyoA null mutant, which exhibits a delay in egress, with TgMyoA in which either S21 or S743 is mutated to alanine failed to rescue the egress defect. Similarly, phosphomimetic mutations in the motor protein overcome the need for TgCDPK3. Moreover, extracellular Tgcdpk3 mutant parasites have motility defects that are complemented by expression of S21+S743 phosphomimetic of TgMyoA. Thus, our studies establish that phosphorylation of TgMyoA by TgCDPK3 is responsible for initiation of motility and parasite egress from the host-cell and provides mechanistic insight into how this unique kinase regulates the lytic cycle of Toxoplasma gondii. Toxoplasma gondii can cause severe disease and death in the immunocompromised and in those infected congenitally. Due to limitations of existing drugs there is a need for studying proteins that are unique and essential to the parasite. We recently established that TgCDPK3, a member of a family of calcium dependent protein kinase present in plants and some parasites but absent in human cells, regulates parasite egress from the host cell. While it has been hypothesized that TgCDPK3 controls rapid exit from the host by phosphorylating proteins needed for activating motility, the particular substrates of this kinase remained unknown. We have now applied an interaction trap system to identify the proteins that are modified by this kinase, which include a parasite motor protein Myosin A (TgMyoA). We show that TgCDPK3 specifically phosphorylates TgMyoA and this phosphorylation is important for parasite egress and motility.
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Affiliation(s)
- Rajshekhar Y. Gaji
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Derrick E. Johnson
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Stark Neuroscience Research Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | | | - Mu Wang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Andy Hudmon
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Stark Neuroscience Research Center, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Gustavo Arrizabalaga
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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48
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Phosphoproteomics reveals malaria parasite Protein Kinase G as a signalling hub regulating egress and invasion. Nat Commun 2015; 6:7285. [PMID: 26149123 PMCID: PMC4507021 DOI: 10.1038/ncomms8285] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 04/26/2015] [Indexed: 12/19/2022] Open
Abstract
Our understanding of the key phosphorylation-dependent signalling pathways in the human malaria parasite, Plasmodium falciparum, remains rudimentary. Here we address this issue for the essential cGMP-dependent protein kinase, PfPKG. By employing chemical and genetic tools in combination with quantitative global phosphoproteomics, we identify the phosphorylation sites on 69 proteins that are direct or indirect cellular targets for PfPKG. These PfPKG targets include proteins involved in cell signalling, proteolysis, gene regulation, protein export and ion and protein transport, indicating that cGMP/PfPKG acts as a signalling hub that plays a central role in a number of core parasite processes. We also show that PfPKG activity is required for parasite invasion. This correlates with the finding that the calcium-dependent protein kinase, PfCDPK1, is phosphorylated by PfPKG, as are components of the actomyosin complex, providing mechanistic insight into the essential role of PfPKG in parasite egress and invasion.
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49
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Mitcheson DF, Tobin AB, Alam MM. Applying chemical genetic tools to the study of phospho-signalling pathways in malaria parasites. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1650-6. [PMID: 26143498 DOI: 10.1016/j.bbapap.2015.06.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 06/25/2015] [Accepted: 06/30/2015] [Indexed: 12/27/2022]
Abstract
Until very recently there has been very little information about the phospho-signalling pathways in apicomplexan parasites including the most virulent species of human malaria parasite, Plasmodium falciparum. With the advancement of mass spectrometry-based phosphoproteomics and the development of chemical genetic approaches to target specific parasite protein kinases, the complexity of the essential role played by phosphorylation in maintaining the viability of apicomplexan parasites is now being revealed. This review will describe these recent advances and will discuss how these approaches can be used to validate parasite protein kinases as drug targets and to determine the on- and off-target action of protein kinase inhibitors. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases.
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Affiliation(s)
- Deborah F Mitcheson
- Department of Cell Physiology and Pharmacology, University of Leicester, Hodgkin Building, Lancaster Road, Leicester LE1 9HN, UK
| | - Andrew B Tobin
- MRC Toxicology Unit, University of Leicester, Hodgkin Building, Lancaster Road, Leicester LE1 9HN, UK
| | - Mahmood M Alam
- MRC Toxicology Unit, University of Leicester, Hodgkin Building, Lancaster Road, Leicester LE1 9HN, UK.
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50
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Odell AV, Tran F, Foderaro JE, Poupart S, Pathak R, Westwood NJ, Ward GE. Yeast three-hybrid screen identifies TgBRADIN/GRA24 as a negative regulator of Toxoplasma gondii bradyzoite differentiation. PLoS One 2015; 10:e0120331. [PMID: 25789621 PMCID: PMC4366382 DOI: 10.1371/journal.pone.0120331] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 02/06/2015] [Indexed: 12/17/2022] Open
Abstract
Differentiation of the protozoan parasite Toxoplasma gondii into its latent bradyzoite stage is a key event in the parasite's life cycle. Compound 2 is an imidazopyridine that was previously shown to inhibit the parasite lytic cycle, in part through inhibition of parasite cGMP-dependent protein kinase. We show here that Compound 2 can also enhance parasite differentiation, and we use yeast three-hybrid analysis to identify TgBRADIN/GRA24 as a parasite protein that interacts directly or indirectly with the compound. Disruption of the TgBRADIN/GRA24 gene leads to enhanced differentiation of the parasite, and the TgBRADIN/GRA24 knockout parasites show decreased susceptibility to the differentiation-enhancing effects of Compound 2. This study represents the first use of yeast three-hybrid analysis to study small-molecule mechanism of action in any pathogenic microorganism, and it identifies a previously unrecognized inhibitor of differentiation in T. gondii. A better understanding of the proteins and mechanisms regulating T. gondii differentiation will enable new approaches to preventing the establishment of chronic infection in this important human pathogen.
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Affiliation(s)
- Anahi V Odell
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
| | - Fanny Tran
- School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, United Kingdom
| | - Jenna E Foderaro
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
| | - Séverine Poupart
- School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, United Kingdom
| | - Ravi Pathak
- School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, United Kingdom
| | - Nicholas J Westwood
- School of Chemistry and Biomedical Sciences Research Complex, University of St. Andrews and EaStCHEM, St Andrews, Fife, Scotland, United Kingdom
| | - Gary E Ward
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
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