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DePasquale JA. A comparison of teleost rodlet cells with apicomplexan cells. Acta Histochem 2024; 126:152167. [PMID: 38733697 DOI: 10.1016/j.acthis.2024.152167] [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: 01/17/2024] [Revised: 04/05/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024]
Abstract
Rodlet cells are unique pear-shaped cells found primarily in the epithelium of the teleost fishes. The rodlet cell was first identified by Thèlohan in 1892 who named it Rhabdospora thelohani as it was believed to be a protozoan parasite of the phylum Apicomplexa. The rodlet cell as parasite paradigm persisted for several decades afterwards but has since faded in the last 20 years or so. The rodlet cell is now generally believed to be an immune cell, functioning as an early responder to parasite intrusion. This short review makes a detailed comparison of apicomplexan structure and behavior with that of the rodlet cell to further strengthen the argument against a parasitic nature for the fish cell. It is then proposed that apical microvilli of the rodlet cell serve as a mechanical trigger for rodlet discharge as possible defense against larger ectoparasites.
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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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Pasquarelli RR, Back PS, Sha J, Wohlschlegel JA, Bradley PJ. Identification of IMC43, a novel IMC protein that collaborates with IMC32 to form an essential daughter bud assembly complex in Toxoplasma gondii. PLoS Pathog 2023; 19:e1011707. [PMID: 37782662 PMCID: PMC10569561 DOI: 10.1371/journal.ppat.1011707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/12/2023] [Accepted: 09/23/2023] [Indexed: 10/04/2023] Open
Abstract
The inner membrane complex (IMC) of Toxoplasma gondii is essential for all phases of the parasite's life cycle. One of its most critical roles is to act as a scaffold for the assembly of daughter buds during replication by endodyogeny. While many daughter IMC proteins have been identified, most are recruited after bud initiation and are not essential for parasite fitness. Here, we report the identification of IMC43, a novel daughter IMC protein that is recruited at the earliest stages of daughter bud initiation. Using an auxin-inducible degron system we show that depletion of IMC43 results in aberrant morphology, dysregulation of endodyogeny, and an extreme defect in replication. Deletion analyses reveal a region of IMC43 that plays a role in localization and a C-terminal domain that is essential for the protein's function. TurboID proximity labelling and a yeast two-hybrid screen using IMC43 as bait identify 30 candidate IMC43 binding partners. We investigate two of these: the essential daughter protein IMC32 and a novel daughter IMC protein we named IMC44. We show that IMC43 is responsible for regulating the localization of both IMC32 and IMC44 at specific stages of endodyogeny and that this regulation is dependent on the essential C-terminal domain of IMC43. Using pairwise yeast two-hybrid assays, we determine that this region is also sufficient for binding to both IMC32 and IMC44. As IMC43 and IMC32 are both essential proteins, this work reveals the existence of a bud assembly complex that forms the foundation of the daughter IMC during endodyogeny.
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Affiliation(s)
- Rebecca R. Pasquarelli
- Molecular Biology Institute, University of California, Los Angeles, California, United States of America
| | - Peter S. Back
- Molecular Biology Institute, University of California, Los Angeles, California, United States of America
| | - Jihui Sha
- Department of Biological Chemistry and Institute of Genomics and Proteomics, University of California, Los Angeles, California, United States of America
| | - James A. Wohlschlegel
- Department of Biological Chemistry and Institute of Genomics and Proteomics, University of California, Los Angeles, California, United States of America
| | - Peter J. Bradley
- Molecular Biology Institute, University of California, Los Angeles, California, United States of America
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California, United States of America
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4
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Back PS, Senthilkumar V, Choi CP, Ly AM, Snyder AK, Lau JG, Ward GE, Bradley PJ. The Toxoplasma subpellicular network is highly interconnected and defines parasite shape for efficient motility and replication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.10.552545. [PMID: 37609316 PMCID: PMC10441382 DOI: 10.1101/2023.08.10.552545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Apicomplexan parasites possess several specialized structures to invade their host cells and replicate successfully. One of these is the inner membrane complex (IMC), a peripheral membrane-cytoskeletal system underneath the plasma membrane. It is composed of a series of flattened, membrane-bound vesicles and a cytoskeletal subpellicular network (SPN) comprised of intermediate filament-like proteins called alveolins. While the alveolin proteins are conserved throughout the Apicomplexa and the broader Alveolata, their precise functions and interactions remain poorly understood. Here, we describe the function of one of these alveolin proteins, TgIMC6. Disruption of IMC6 resulted in striking morphological defects that led to aberrant motility, invasion, and replication. Deletion analyses revealed that the alveolin domain alone is largely sufficient to restore localization and partially sufficient for function. As this highlights the importance of the IMC6 alveolin domain, we implemented unnatural amino acid photoreactive crosslinking to the alveolin domain and identified multiple binding interfaces between IMC6 and two other cytoskeletal proteins - IMC3 and ILP1. To our knowledge, this provides the first direct evidence of protein-protein interactions in the alveolin domain and supports the long-held hypothesis that the alveolin domain is responsible for filament formation. Collectively, our study features the conserved alveolin proteins as critical components that maintain the parasite's structural integrity and highlights the alveolin domain as a key mediator of SPN architecture.
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5
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Mansfield CR, Chirgwin ME, Derbyshire ER. Labeling strategies to track protozoan parasite proteome dynamics. Curr Opin Chem Biol 2023; 75:102316. [PMID: 37192562 PMCID: PMC10895934 DOI: 10.1016/j.cbpa.2023.102316] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/07/2023] [Accepted: 04/10/2023] [Indexed: 05/18/2023]
Abstract
Intracellular protozoan parasites are responsible for wide-spread infectious diseases. These unicellular pathogens have complex, multi-host life cycles, which present challenges for investigating their basic biology and for discovering vulnerabilities that could be exploited for disease control. Throughout development, parasite proteomes are dynamic and support stage-specific functions, but detection of these proteins is often technically challenging and complicated by the abundance of host proteins. Thus, to elucidate key parasite processes and host-pathogen interactions, labeling strategies are required to track pathogen proteins during infection. Herein, we discuss the application of bioorthogonal non-canonical amino acid tagging and proximity-dependent labeling to broadly study protozoan parasites and include outlooks for future applications to study Plasmodium, the causative agent of malaria. We highlight the potential of these technologies to provide spatiotemporal labeling with selective parasite protein enrichment, which could enable previously unattainable insight into the biology of elusive developmental stages.
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Affiliation(s)
| | | | - Emily R Derbyshire
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA; Department of Chemistry, Duke University, Durham, NC, USA.
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6
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Abstract
The biology of a cell, whether it is a unicellular organism or part of a multicellular network, is influenced by cell type, temporal changes in cell state, and the cell's environment. Spatial cues play a critical role in the regulation of microbial pathogenesis strategies. Information about where the pathogen is-in a tissue or in proximity to a host cell-regulates gene expression and the compartmentalization of gene products in the microbe and the host. Our understanding of host and pathogen identity has bloomed with the accessibility of transcriptomics and proteomics techniques. A missing piece of the puzzle has been our ability to evaluate global transcript and protein expression in the context of the subcellular niche, primary cell, or native tissue environment during infection. This barrier is now lower with the advent of new spatial omics techniques to understand how location regulates cellular functions. This review will discuss how recent advances in spatial proteomics and transcriptomics approaches can address outstanding questions in microbial pathogenesis.
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Affiliation(s)
- Samantha Lempke
- Department of Microbiology, Immunology, and Cancer Biology at the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Dana May
- Department of Microbiology, Immunology, and Cancer Biology at the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Sarah E. Ewald
- Department of Microbiology, Immunology, and Cancer Biology at the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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7
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O’Shaughnessy WJ, Hu X, Henriquez SA, Reese ML. Toxoplasma ERK7 protects the apical complex from premature degradation. J Cell Biol 2023; 222:e202209098. [PMID: 37027006 PMCID: PMC10083718 DOI: 10.1083/jcb.202209098] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 02/01/2023] [Accepted: 03/17/2023] [Indexed: 04/08/2023] Open
Abstract
Accurate cellular replication balances the biogenesis and turnover of complex structures. In the apicomplexan parasite Toxoplasma gondii, daughter cells form within an intact mother cell, creating additional challenges to ensuring fidelity of division. The apical complex is critical to parasite infectivity and consists of apical secretory organelles and specialized cytoskeletal structures. We previously identified the kinase ERK7 as required for maturation of the apical complex in Toxoplasma. Here, we define the Toxoplasma ERK7 interactome, including a putative E3 ligase, CSAR1. Genetic disruption of CSAR1 fully suppresses loss of the apical complex upon ERK7 knockdown. Furthermore, we show that CSAR1 is normally responsible for turnover of maternal cytoskeleton during cytokinesis, and that its aberrant function is driven by mislocalization from the parasite residual body to the apical complex. These data identify a protein homeostasis pathway critical for Toxoplasma replication and fitness and suggest an unappreciated role for the parasite residual body in compartmentalizing processes that threaten the fidelity of parasite development.
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Affiliation(s)
| | - Xiaoyu Hu
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - Sarah Ana Henriquez
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
| | - Michael L. Reese
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, TX, USA
- Department of Biochemistry, University of Texas, Southwestern Medical Center, Dallas, TX, USA
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8
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Koreny L, Mercado-Saavedra BN, Klinger CM, Barylyuk K, Butterworth S, Hirst J, Rivera-Cuevas Y, Zaccai NR, Holzer VJC, Klingl A, Dacks JB, Carruthers VB, Robinson MS, Gras S, Waller RF. Stable endocytic structures navigate the complex pellicle of apicomplexan parasites. Nat Commun 2023; 14:2167. [PMID: 37061511 PMCID: PMC10105704 DOI: 10.1038/s41467-023-37431-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 03/17/2023] [Indexed: 04/17/2023] Open
Abstract
Apicomplexan parasites have immense impacts on humanity, but their basic cellular processes are often poorly understood. Where endocytosis occurs in these cells, how conserved this process is with other eukaryotes, and what the functions of endocytosis are across this phylum are major unanswered questions. Using the apicomplexan model Toxoplasma, we identified the molecular composition and behavior of unusual, fixed endocytic structures. Here, stable complexes of endocytic proteins differ markedly from the dynamic assembly/disassembly of these machineries in other eukaryotes. We identify that these endocytic structures correspond to the 'micropore' that has been observed throughout the Apicomplexa. Moreover, conserved molecular adaptation of this structure is seen in apicomplexans including the kelch-domain protein K13 that is central to malarial drug-resistance. We determine that a dominant function of endocytosis in Toxoplasma is plasma membrane homeostasis, rather than parasite nutrition, and that these specialized endocytic structures originated early in infrakingdom Alveolata likely in response to the complex cell pellicle that defines this medically and ecologically important ancient eukaryotic lineage.
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Affiliation(s)
- Ludek Koreny
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
| | | | - Christen M Klinger
- Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | | | - Simon Butterworth
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Jennifer Hirst
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Yolanda Rivera-Cuevas
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Nathan R Zaccai
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Victoria J C Holzer
- Plant Development, Ludwig-Maximilians-University Munich, Planegg-Martinsried, 82152, Germany
| | - Andreas Klingl
- Plant Development, Ludwig-Maximilians-University Munich, Planegg-Martinsried, 82152, Germany
| | - Joel B Dacks
- Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, AB, T6G 2R3, Canada
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czech Republic
| | - Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Margaret S Robinson
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Simon Gras
- Experimental Parasitology, Department for Veterinary Sciences, Ludwig-Maximilians-University Munich, Planegg-Martinsried, 82152, Germany.
| | - Ross F Waller
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK.
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9
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Back PS, Moon AS, Pasquarelli RR, Bell HN, Torres JA, Chen AL, Sha J, Vashisht AA, Wohlschlegel JA, Bradley PJ. IMC29 Plays an Important Role in Toxoplasma Endodyogeny and Reveals New Components of the Daughter-Enriched IMC Proteome. mBio 2023; 14:e0304222. [PMID: 36622147 PMCID: PMC9973257 DOI: 10.1128/mbio.03042-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 12/07/2022] [Indexed: 01/10/2023] Open
Abstract
The Toxoplasma inner membrane complex (IMC) is a unique organelle that plays critical roles in parasite motility, invasion, egress, and replication. The IMC is delineated into the apical, body, and basal regions, defined by proteins that localize to these distinct subcompartments. The IMC can be further segregated by proteins that localize specifically to the maternal IMC, the daughter bud IMC, or both. While the function of the maternal IMC has been better characterized, the precise roles of most daughter IMC components remain poorly understood. Here, we demonstrate that the daughter protein IMC29 plays an important role in parasite replication. We show that Δimc29 parasites exhibit severe replication defects, resulting in substantial growth defects and loss of virulence. Deletion analyses revealed that IMC29 localization is largely dependent on the N-terminal half of the protein containing four predicted coiled-coil domains while IMC29 function requires a short C-terminal helical region. Using proximity labeling, we identify eight novel IMC proteins enriched in daughter buds, significantly expanding the daughter IMC proteome. We additionally report four novel proteins with unique localizations to the interface between two parasites or to the outer face of the IMC, exposing new subregions of the organelle. Together, this work establishes IMC29 as an important early daughter bud component of replication and uncovers an array of new IMC proteins that provides important insights into this organelle. IMPORTANCE The inner membrane complex (IMC) is a conserved structure across the Apicomplexa phylum, which includes obligate intracellular parasites that cause toxoplasmosis, malaria, and cryptosporidiosis. The IMC is critical for the parasite to maintain its intracellular lifestyle, particularly in providing a scaffold for daughter bud formation during parasite replication. While many IMC proteins in the later stages of division have been identified, components of the early stages of division remain unknown. Here, we focus on the early daughter protein IMC29, demonstrating that it is crucial for faithful parasite replication and identifying specific regions of the protein that are important for its localization and function. We additionally use proximity labeling to reveal a suite of daughter-enriched IMC proteins, which represent promising candidates to further explore this IMC subcompartment.
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Affiliation(s)
- Peter S. Back
- Molecular Biology Institute, University of California, Los Angeles, California, USA
| | - Andy S. Moon
- Department of Molecular Microbiology and Immunology, University of California, Los Angeles, California, USA
| | | | - Hannah N. Bell
- Department of Molecular Microbiology and Immunology, University of California, Los Angeles, California, USA
| | - Juan A. Torres
- Department of Molecular Microbiology and Immunology, University of California, Los Angeles, California, USA
| | - Allan L. Chen
- Department of Molecular Microbiology and Immunology, University of California, Los Angeles, California, USA
| | - Jihui Sha
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Ajay A. Vashisht
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - James A. Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Peter J. Bradley
- Department of Molecular Microbiology and Immunology, University of California, Los Angeles, California, USA
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10
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Huet D, Moreno SNJ. Interorganellar Communication Through Membrane Contact Sites in Toxoplasma Gondii. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2023; 6:25152564231189064. [PMID: 37560622 PMCID: PMC10408353 DOI: 10.1177/25152564231189064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 08/11/2023]
Abstract
Apicomplexan parasites are a group of protists that cause disease in humans and include pathogens like Plasmodium spp., the causative agent of malaria, and Toxoplasma gondii, the etiological agent of toxoplasmosis and one of the most ubiquitous human parasites in the world. Membrane contact sites (MCSs) are widespread structures within eukaryotic cells but their characterization in apicomplexan parasites is only in its very beginnings. Basic biological features of the T. gondii parasitic cycle support numerous organellar interactions, including the transfer of Ca2+ and metabolites between different compartments. In T. gondii, Ca2+ signals precede a series of interrelated molecular processes occurring in a coordinated manner that culminate in the stimulation of key steps of the parasite life cycle. Calcium transfer from the endoplasmic reticulum to other organelles via MCSs would explain the precision, speed, and efficiency that is needed during the lytic cycle of T. gondii. In this short review, we discuss the implications of these structures in cellular signaling, with an emphasis on their potential role in Ca2+ signaling.
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Affiliation(s)
- Diego Huet
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
- Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA, USA
| | - Silvia N. J. Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
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11
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Roumégous C, Abou Hammoud A, Fuster D, Dupuy JW, Blancard C, Salin B, Robinson DR, Renesto P, Tardieux I, Frénal K. Identification of new components of the basal pole of Toxoplasma gondii provides novel insights into its molecular organization and functions. Front Cell Infect Microbiol 2022; 12:1010038. [PMID: 36310866 PMCID: PMC9613666 DOI: 10.3389/fcimb.2022.1010038] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
The Toxoplasma gondii tachyzoite is a singled-cell obligate intracellular parasite responsible for the acute phase of toxoplasmosis. This polarized cell exhibits an apical complex, a hallmark of the phylum Apicomplexa, essential for motility, invasion, and egress from the host cell. Located on the opposite end of the cell is the basal complex, an elaborated cytoskeletal structure that also plays critical roles in the lytic cycle of the parasite, being involved in motility, cell division, constriction and cytokinesis, as well as intravacuolar cell-cell communication. Nevertheless, only a few proteins of this structure have been described and functionally assessed. In this study, we used spatial proteomics to identify new basal complex components (BCC), and in situ imaging, including ultrastructure expansion microscopy, to position them. We thus confirmed the localization of nine BCCs out of the 12 selected candidates and assigned them to different sub-compartments of the basal complex, including two new domains located above the basal ring and below the posterior cup. Their functional investigation revealed that none of these BCCs are essential for parasite growth in vitro. However, one BCC is critical for constricting of the basal complex, likely through direct interaction with the class VI myosin heavy chain J (MyoJ), and for gliding motility. Four other BCCs, including a phosphatase and a guanylate-binding protein, are involved in the formation and/or maintenance of the intravacuolar parasite connection, which is required for the rosette organization and synchronicity of cell division.
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Affiliation(s)
- Chloé Roumégous
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Aya Abou Hammoud
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Damien Fuster
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | | | - Corinne Blancard
- Univ. Bordeaux, CNRS, Institut de Biochimie et Génétique Cellulaires, UMR 5095, Bordeaux, France
| | - Bénédicte Salin
- Univ. Bordeaux, CNRS, Institut de Biochimie et Génétique Cellulaires, UMR 5095, Bordeaux, France
| | - Derrick R. Robinson
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Patricia Renesto
- IAB, Team Biomechanics of Host-Apicomplexa Parasite, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, Grenoble, France
| | - Isabelle Tardieux
- IAB, Team Biomechanics of Host-Apicomplexa Parasite, INSERM U1209, CNRS UMR5309, Grenoble Alpes University, Grenoble, France
| | - Karine Frénal
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
- *Correspondence: Karine Frénal,
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12
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Engelberg K, Bechtel T, Michaud C, Weerapana E, Gubbels MJ. Proteomic characterization of the Toxoplasma gondii cytokinesis machinery portrays an expanded hierarchy of its assembly and function. Nat Commun 2022; 13:4644. [PMID: 35941170 PMCID: PMC9360017 DOI: 10.1038/s41467-022-32151-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 07/15/2022] [Indexed: 12/01/2022] Open
Abstract
The basal complex (BC) is essential for T. gondii cell division but mechanistic details are lacking. Here we report a reciprocal proximity based biotinylation approach to map the BC’s proteome. We interrogate the resulting map for spatiotemporal dynamics and function by disrupting the expression of components. This highlights four architecturally distinct BC subcomplexes, the compositions of which change dynamically in correlation with changes in BC function. We identify BCC0 as a protein undergirding BC formation in five foci that precede the same symmetry seen in the apical annuli and IMC sutures. Notably, daughter budding from BCC0 progresses bidirectionally: the apical cap in apical and the rest of the IMC in basal direction. Furthermore, the essential role of the BC in cell division is contained in BCC4 and MORN1 that form a ‘rubber band’ to sequester the basal end of the assembling daughter cytoskeleton. Finally, we assign BCC1 to the non-essential, final BC constriction step. The basal complex is orchestrating Toxoplasma gondii cell division steps. Here, the authors use proximity biotinylation to map the proteome of this contractile ring, identify components acting on its formation, stability and constriction, and reveal bidirectional daughter budding.
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Affiliation(s)
| | - Tyler Bechtel
- Department of Chemistry, Boston College, Chestnut Hill, MA, USA
| | - Cynthia Michaud
- Department of Biology, Boston College, Chestnut Hill, MA, USA
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13
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Cryo-ET of Toxoplasma parasites gives subnanometer insight into tubulin-based structures. Proc Natl Acad Sci U S A 2022; 119:2111661119. [PMID: 35121661 PMCID: PMC8832990 DOI: 10.1073/pnas.2111661119] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2021] [Indexed: 11/18/2022] Open
Abstract
Tubulin polymers are essential for a variety of cellular functions. Using cryo-ET, we reveal the 3D organization of the apical complex in Toxoplasma gondii, an intracellular eukaryote with tubulin-based structures, including an apical “conoid” involved in host cell invasion. Our development of an advanced subtomogram averaging protocol for filamentous structures enabled us to accurately assign tubulins in cellular context. At the subnanometer resolution achieved, tubulins were confirmed to assemble into two major forms: canonical subpellicular microtubules (SPMTs) and noncanonical conoid fibrils (CFs). The data further revealed associated proteins in both structures, a dominant orientation of SPMTs, and a unique patterning of the CFs. This work demonstrates an approach that can be used to determine cellular filamentous structures at multiscale resolutions. Tubulin is a conserved protein that polymerizes into different forms of filamentous structures in Toxoplasma gondii, an obligate intracellular parasite in the phylum Apicomplexa. Two key tubulin-containing cytoskeletal components are subpellicular microtubules (SPMTs) and conoid fibrils (CFs). The SPMTs help maintain shape and gliding motility, while the CFs are implicated in invasion. Here, we use cryogenic electron tomography to determine the molecular structures of the SPMTs and CFs in vitrified intact and detergent-extracted parasites. Subvolume densities from detergent-extracted parasites yielded averaged density maps at subnanometer resolutions, and these were related back to their architecture in situ. An intralumenal spiral lines the interior of the 13-protofilament SPMTs, revealing a preferred orientation of these microtubules relative to the parasite’s long axis. Each CF is composed of nine tubulin protofilaments that display a comma-shaped cross-section, plus additional associated components. Conoid protrusion, a crucial step in invasion, is associated with an altered pitch of each CF. The use of basic building blocks of protofilaments and different accessory proteins in one organism illustrates the versatility of tubulin to form two distinct types of assemblies, SPMTs and CFs.
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14
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Dos Santos Pacheco N, Tosetti N, Krishnan A, Haase R, Maco B, Suarez C, Ren B, Soldati-Favre D. Revisiting the Role of Toxoplasma gondii ERK7 in the Maintenance and Stability of the Apical Complex. mBio 2021; 12:e0205721. [PMID: 34607461 PMCID: PMC8546650 DOI: 10.1128/mbio.02057-21] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/02/2021] [Indexed: 12/02/2022] Open
Abstract
Toxoplasma gondii extracellular signal-regulated kinase 7 (ERK7) is known to contribute to the integrity of the apical complex and to participate in the final step of conoid biogenesis. In the absence of ERK7, mature parasites lose their conoid complex and are unable to glide, invade, or egress from host cells. In contrast to a previous report, we show here that the depletion of ERK7 phenocopies the depletion of the apical cap protein AC9 or AC10. The absence of ERK7 leads to the loss of the apical polar ring (APR), the disorganization of the basket of subpellicular microtubules (SPMTs), and a severe impairment in microneme secretion. Ultrastructure expansion microscopy (U-ExM), coupled to N-hydroxysuccinimide ester (NHS-ester) staining on intracellular parasites, offers an unprecedented level of resolution and highlights the disorganization of the rhoptries as well as the dilated plasma membrane at the apical pole in the absence of ERK7. Comparative proteomics analysis of wild-type and ERK7-depleted parasites confirmed the disappearance of known apical complex proteins, including markers of the apical polar ring and a new apical cap named AC11. Concomitantly, the absence of ERK7 led to an accumulation of microneme proteins, resulting from the defect in the exocytosis of the organelles. AC9-depleted parasites were included as controls and exhibited an increase in inner membrane complex proteins, with two new proteins assigned to this compartment, namely, IMC33 and IMC34. IMPORTANCE The conoid is an enigmatic, dynamic organelle positioned at the apical tip of the coccidian subgroup of the Apicomplexa, close to the apical polar ring (APR) from which the subpellicular microtubules (SPMTs) emerge and through which the secretory organelles (micronemes and rhoptries) reach the plasma membrane for exocytosis. In Toxoplasma gondii, the conoid protrudes concomitantly with microneme secretion, during egress, motility, and invasion. The conditional depletion of the apical cap structural protein AC9 or AC10 leads to a disorganization of SPMTs as well as the loss of the APR and conoid, resulting in a microneme secretion defect and a block in motility, invasion, and egress. We show here that the depletion of the kinase ERK7 phenocopies AC9 and AC10 mutants. The combination of ultrastructure expansion microscopy and NHS-ester staining revealed that ERK7-depleted parasites exhibit a dilated apical plasma membrane and an altered positioning of the rhoptries, while electron microscopy images unambiguously highlight the loss of the APR.
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Affiliation(s)
- Nicolas Dos Santos Pacheco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Nicolò Tosetti
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Aarti Krishnan
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Romuald Haase
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Bohumil Maco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Catherine Suarez
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Bingjian Ren
- 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
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15
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A Novel Toxoplasma Inner Membrane Complex Suture-Associated Protein Regulates Suture Protein Targeting and Colocalizes with Membrane Trafficking Machinery. mBio 2021; 12:e0245521. [PMID: 34634933 PMCID: PMC8510555 DOI: 10.1128/mbio.02455-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The cytoskeleton of Toxoplasma gondii is composed of the inner membrane complex (IMC) and an array of underlying microtubules that provide support at the periphery of the parasite. Specific subregions of the IMC carry out distinct roles in replication, motility, and host cell invasion. Building on our previous in vivo biotinylation (BioID) experiments of the IMC, we identified here a novel protein that localizes to discrete puncta that are embedded in the parasite’s cytoskeleton along the IMC sutures. Gene knockout analysis showed that loss of the protein results in defects in cytoskeletal suture protein targeting, cytoskeletal integrity, parasite morphology, and host cell invasion. We then used deletion analyses to identify a domain in the N terminus of the protein that is critical for both localization and function. Finally, we used the protein as bait for in vivo biotinylation, which identified several other proteins that colocalize in similar spot-like patterns. These putative interactors include several proteins that are implicated in membrane trafficking and are also associated with the cytoskeleton. Together, these data reveal an unexpected link between the IMC sutures and membrane trafficking elements of the parasite and suggest that the suture puncta are likely a portal for trafficking cargo across the IMC.
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16
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Kimmel J, Kehrer J, Frischknecht F, Spielmann T. Proximity-dependent biotinylation approaches to study apicomplexan biology. Mol Microbiol 2021; 117:553-568. [PMID: 34587292 DOI: 10.1111/mmi.14815] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 09/20/2021] [Indexed: 11/28/2022]
Abstract
In the last 10 years, proximity-dependent biotinylation (PDB) techniques greatly expanded the ability to study protein environments in the living cell that range from specific protein complexes to entire compartments. This is achieved by using enzymes such as BirA* and APEX that are fused to proteins of interest and biotinylate proteins in their proximity. PDB techniques are now also increasingly used in apicomplexan parasites. In this review, we first give an overview of the main PDB approaches and how they compare with other techniques that address similar questions. PDB is particularly valuable to detect weak or transient protein associations under physiological conditions and to study cellular structures that are difficult to purify or have a poorly understood protein composition. We also highlight new developments such as novel smaller or faster-acting enzyme variants and conditional PDB approaches, providing improvements in both temporal and spatial resolution which may offer broader application possibilities useful in apicomplexan research. In the second part, we review work using PDB techniques in apicomplexan parasites and how this expanded our knowledge about these medically important parasites.
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Affiliation(s)
- Jessica Kimmel
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jessica Kehrer
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany.,German Center for Infectious Disease Research, DZIF, Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany.,German Center for Infectious Disease Research, DZIF, Heidelberg, Germany
| | - Tobias Spielmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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17
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Plasmodium falciparum goes bananas for sex. Mol Biochem Parasitol 2021; 244:111385. [PMID: 34062177 DOI: 10.1016/j.molbiopara.2021.111385] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 05/19/2021] [Accepted: 05/27/2021] [Indexed: 11/22/2022]
Abstract
The sexual blood stages of the human malaria parasite Plasmodium falciparum undergo a remarkable transformation from a roughly spherical shape to an elongated crescent or "falciform" morphology from which the species gets its name. In this review, the molecular events that drive this spectacular shape change are discussed and some questions that remain regarding the mechanistic underpinnings are posed. We speculate on the role of the shape changes in promoting sequestration and release of the developing gametocyte, thereby facilitating parasite survival in the host and underpinning transmission to the mosquito vector.
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18
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Wichers JS, Wunderlich J, Heincke D, Pazicky S, Strauss J, Schmitt M, Kimmel J, Wilcke L, Scharf S, von Thien H, Burda PC, Spielmann T, Löw C, Filarsky M, Bachmann A, Gilberger TW. Identification of novel inner membrane complex and apical annuli proteins of the malaria parasite Plasmodium falciparum. Cell Microbiol 2021; 23:e13341. [PMID: 33830607 DOI: 10.1111/cmi.13341] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/29/2021] [Accepted: 04/05/2021] [Indexed: 02/06/2023]
Abstract
The inner membrane complex (IMC) is a defining feature of apicomplexan parasites, which confers stability and shape to the cell, functions as a scaffolding compartment during the formation of daughter cells and plays an important role in motility and invasion during different life cycle stages of these single-celled organisms. To explore the IMC proteome of the malaria parasite Plasmodium falciparum we applied a proximity-dependent biotin identification (BioID)-based proteomics approach, using the established IMC marker protein Photosensitized INA-Labelled protein 1 (PhIL1) as bait in asexual blood-stage parasites. Subsequent mass spectrometry-based peptide identification revealed enrichment of 12 known IMC proteins and several uncharacterized candidate proteins. We validated nine of these previously uncharacterized proteins by endogenous GFP-tagging. Six of these represent new IMC proteins, while three proteins have a distinct apical localization that most likely represents structures described as apical annuli in Toxoplasma gondii. Additionally, various Kelch13 interacting candidates were identified, suggesting an association of the Kelch13 compartment and the IMC in schizont and merozoite stages. This work extends the number of validated IMC proteins in the malaria parasite and reveals for the first time the existence of apical annuli proteins in P. falciparum. Additionally, it provides evidence for a spatial association between the Kelch13 compartment and the IMC in late blood-stage parasites.
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Affiliation(s)
- Jan Stephan Wichers
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Juliane Wunderlich
- Centre for Structural Systems Biology, Hamburg, Germany.,European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Dorothee Heincke
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Samuel Pazicky
- Centre for Structural Systems Biology, Hamburg, Germany.,European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Jan Strauss
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Marius Schmitt
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jessica Kimmel
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Louisa Wilcke
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Sarah Scharf
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Heidrun von Thien
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Paul-Christian Burda
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Tobias Spielmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Christian Löw
- Centre for Structural Systems Biology, Hamburg, Germany.,European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Michael Filarsky
- Centre for Structural Systems Biology, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
| | - Anna Bachmann
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany.,German Centre for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Braunschweig, Germany
| | - Tim W Gilberger
- Centre for Structural Systems Biology, Hamburg, Germany.,Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,University of Hamburg, Hamburg, Germany
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19
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Pyrih J, Žárský V, Fellows JD, Grosche C, Wloga D, Striepen B, Maier UG, Tachezy J. The iron-sulfur scaffold protein HCF101 unveils the complexity of organellar evolution in SAR, Haptista and Cryptista. BMC Ecol Evol 2021; 21:46. [PMID: 33740894 PMCID: PMC7980591 DOI: 10.1186/s12862-021-01777-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/08/2021] [Indexed: 11/22/2022] Open
Abstract
Background Nbp35-like proteins (Nbp35, Cfd1, HCF101, Ind1, and AbpC) are P-loop NTPases that serve as components of iron-sulfur cluster (FeS) assembly machineries. In eukaryotes, Ind1 is present in mitochondria, and its function is associated with the assembly of FeS clusters in subunits of respiratory Complex I, Nbp35 and Cfd1 are the components of the cytosolic FeS assembly (CIA) pathway, and HCF101 is involved in FeS assembly of photosystem I in plastids of plants (chHCF101). The AbpC protein operates in Bacteria and Archaea. To date, the cellular distribution of these proteins is considered to be highly conserved with only a few exceptions. Results We searched for the genes of all members of the Nbp35-like protein family and analyzed their targeting sequences. Nbp35 and Cfd1 were predicted to reside in the cytoplasm with some exceptions of Nbp35 localization to the mitochondria; Ind1was found in the mitochondria, and HCF101 was predicted to reside in plastids (chHCF101) of all photosynthetically active eukaryotes. Surprisingly, we found a second HCF101 paralog in all members of Cryptista, Haptista, and SAR that was predicted to predominantly target mitochondria (mHCF101), whereas Ind1 appeared to be absent in these organisms. We also identified a few exceptions, as apicomplexans possess mHCF101 predicted to localize in the cytosol and Nbp35 in the mitochondria. Our predictions were experimentally confirmed in selected representatives of Apicomplexa (Toxoplasma gondii), Stramenopila (Phaeodactylum tricornutum, Thalassiosira pseudonana), and Ciliophora (Tetrahymena thermophila) by tagging proteins with a transgenic reporter. Phylogenetic analysis suggested that chHCF101 and mHCF101 evolved from a common ancestral HCF101 independently of the Nbp35/Cfd1 and Ind1 proteins. Interestingly, phylogenetic analysis supports rather a lateral gene transfer of ancestral HCF101 from bacteria than its acquisition being associated with either α-proteobacterial or cyanobacterial endosymbionts. Conclusion Our searches for Nbp35-like proteins across eukaryotic lineages revealed that SAR, Haptista, and Cryptista possess mitochondrial HCF101. Because plastid localization of HCF101 was only known thus far, the discovery of its mitochondrial paralog explains confusion regarding the presence of HCF101 in organisms that possibly lost secondary plastids (e.g., ciliates, Cryptosporidium) or possess reduced nonphotosynthetic plastids (apicomplexans). Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01777-x.
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Affiliation(s)
- Jan Pyrih
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25250, Vestec, Czech Republic
| | - Vojtěch Žárský
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25250, Vestec, Czech Republic
| | - Justin D Fellows
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Christopher Grosche
- Laboratory for Cell Biology, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35032, Marburg, Germany.,LOEWE Center for Synthetic Microbiology (Synmikro), Hans-Meerwein-Str. 6, 35032, Marburg, Germany
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warsaw, Poland
| | - Boris Striepen
- Department of Cellular Biology, University of Georgia, Athens, GA, USA.,Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 380 South University Avenue, Philadelphia, PA, 19104, USA
| | - Uwe G Maier
- Laboratory for Cell Biology, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35032, Marburg, Germany.,LOEWE Center for Synthetic Microbiology (Synmikro), Hans-Meerwein-Str. 6, 35032, Marburg, Germany
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25250, Vestec, Czech Republic.
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20
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Koreny L, Zeeshan M, Barylyuk K, Tromer EC, van Hooff JJE, Brady D, Ke H, Chelaghma S, Ferguson DJP, Eme L, Tewari R, Waller RF. Molecular characterization of the conoid complex in Toxoplasma reveals its conservation in all apicomplexans, including Plasmodium species. PLoS Biol 2021; 19:e3001081. [PMID: 33705380 PMCID: PMC7951837 DOI: 10.1371/journal.pbio.3001081] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/17/2020] [Indexed: 12/14/2022] Open
Abstract
The apical complex is the instrument of invasion used by apicomplexan parasites, and the conoid is a conspicuous feature of this apparatus found throughout this phylum. The conoid, however, is believed to be heavily reduced or missing from Plasmodium species and other members of the class Aconoidasida. Relatively few conoid proteins have previously been identified, making it difficult to address how conserved this feature is throughout the phylum, and whether it is genuinely missing from some major groups. Moreover, parasites such as Plasmodium species cycle through 3 invasive forms, and there is the possibility of differential presence of the conoid between these stages. We have applied spatial proteomics and high-resolution microscopy to develop a more complete molecular inventory and understanding of the organisation of conoid-associated proteins in the model apicomplexan Toxoplasma gondii. These data revealed molecular conservation of all conoid substructures throughout Apicomplexa, including Plasmodium, and even in allied Myzozoa such as Chromera and dinoflagellates. We reporter-tagged and observed the expression and location of several conoid complex proteins in the malaria model P. berghei and revealed equivalent structures in all of its zoite forms, as well as evidence of molecular differentiation between blood-stage merozoites and the ookinetes and sporozoites of the mosquito vector. Collectively, we show that the conoid is a conserved apicomplexan element at the heart of the invasion mechanisms of these highly successful and often devastating parasites.
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Affiliation(s)
- Ludek Koreny
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Mohammad Zeeshan
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Konstantin Barylyuk
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Eelco C. Tromer
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Jolien J. E. van Hooff
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, Orsay, France
| | - Declan Brady
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Huiling Ke
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Sara Chelaghma
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - David J. P. Ferguson
- Nuffield Department of Clinical Laboratory Science, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford, United Kingdom
| | - Laura Eme
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, Orsay, France
| | - Rita Tewari
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Ross F. Waller
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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21
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Multivalent Interactions Drive the Toxoplasma AC9:AC10:ERK7 Complex To Concentrate ERK7 in the Apical Cap. mBio 2021; 13:e0286421. [PMID: 35130732 PMCID: PMC8822341 DOI: 10.1128/mbio.02864-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The Toxoplasma inner membrane complex (IMC) is a specialized organelle that is crucial for the parasite to establish an intracellular lifestyle and ultimately cause disease. The IMC is composed of both membrane and cytoskeletal components, further delineated into the apical cap, body, and basal subcompartments. The apical cap cytoskeleton was recently demonstrated to govern the stability of the apical complex, which controls parasite motility, invasion, and egress. While this role was determined by individually assessing the apical cap proteins AC9, AC10, and the mitogen-activated protein kinase ERK7, how the three proteins collaborate to stabilize the apical complex is unknown. In this study, we use a combination of deletion analyses and yeast two-hybrid experiments to establish that these proteins form an essential complex in the apical cap. We show that AC10 is a foundational component of the AC9:AC10:ERK7 complex and demonstrate that the interactions among them are critical to maintaining the apical complex. Importantly, we identify multiple independent regions of pairwise interaction between each of the three proteins, suggesting that the AC9:AC10:ERK7 complex is organized by multivalent interactions. Together, these data support a model in which multiple interacting domains enable the oligomerization of the AC9:AC10:ERK7 complex and its assembly into the cytoskeletal IMC, which serves as a structural scaffold that concentrates ERK7 kinase activity in the apical cap. IMPORTANCE The phylum Apicomplexa consists of obligate, intracellular parasites, including the causative agents of toxoplasmosis, malaria, and cryptosporidiosis. Hallmarks of these parasites are the IMC and the apical complex, both of which are unique structures that are conserved throughout the phylum and required for parasite survival. The apical cap portion of the IMC has previously been shown to stabilize the apical complex. Here, we expand on those studies to determine the precise protein-protein interactions of the apical cap complex that confer this essential function. We describe the multivalent nature of these interactions and show that the resulting protein oligomers likely tether ERK7 in the apical cap. This study represents the first description of the architecture of the apical cap at a molecular level, expanding our understanding of the unique cell biology that drives Toxoplasma infections.
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22
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Identification and Molecular Dissection of IMC32, a Conserved Toxoplasma Inner Membrane Complex Protein That Is Essential for Parasite Replication. mBio 2021; 12:mBio.03622-20. [PMID: 33593973 PMCID: PMC8545131 DOI: 10.1128/mbio.03622-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The inner membrane complex (IMC) is a unique organelle of apicomplexan parasites that plays critical roles in parasite motility, host cell invasion, and replication. Despite the common functions of the organelle, relatively few IMC proteins are conserved across the phylum and the precise roles of many IMC components remain to be characterized. Here, we identify a novel component of the Toxoplasma gondii IMC (IMC32) that localizes to the body portion of the IMC and is recruited to developing daughter buds early during endodyogeny. IMC32 is essential for parasite survival, as its conditional depletion results in a complete collapse of the IMC that is lethal to the parasite. We demonstrate that localization of IMC32 is dependent on both an N-terminal palmitoylation site and a series of C-terminal coiled-coil domains. Using deletion analyses and functional complementation, we show that two conserved regions within the C-terminal coiled-coil domains play critical roles in protein function during replication. Together, this work reveals an essential component of parasite replication that provides a novel target for therapeutic intervention of T. gondii and related apicomplexan parasites.IMPORTANCE The IMC is an important organelle that apicomplexan parasites use to maintain their intracellular lifestyle. While many IMC proteins have been identified, only a few central players that are essential for internal budding have been described and even fewer are conserved across the phylum. Here, we identify IMC32, a novel component of the Toxoplasma gondii IMC that localizes to very early daughter buds, indicating a role in the early stages of parasite replication. We then demonstrate that IMC32 is essential for parasite survival and pinpoint conserved regions within the protein that are important for membrane association and daughter cell formation. As IMC32 is unique to these parasites and not present in their mammalian hosts, it serves as a new target for the development of drugs that exclusively affect these important intracellular pathogens.
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23
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Wang C, Hu D, Tang X, Song X, Wang S, Zhang S, Duan C, Sun P, Suo J, Ma H, Suo X, Liu X. Internal daughter formation of Toxoplasma gondii tachyzoites is coordinated by transcription factor TgAP2IX-5. Cell Microbiol 2020; 23:e13291. [PMID: 33217129 DOI: 10.1111/cmi.13291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 02/06/2023]
Abstract
Toxoplasma gondii rapidly propagates through endodyogeny of tachyzoites, a process in which daughter parasites divide within the cell of the mother parasite. Recent studies have revealed that transcription factors with AP2-domain participate in the process of cell division in T. gondii. However, the concise regulation of the division cycles by AP2 proteins is poorly understood. In this study, we evaluated the effect of the transcription factor TgAP2IX-5 on the daughter cell formation in T. gondii. TgAP2IX-5 is a nuclear protein and is highly expressed during the S phase of the cell cycle of tachyzoites. TgAP2IX-5-disrupted strain showed a severe defect in replication and completely blocked lytic parasite growth. Following 3-indoleacetic acid treatment or without treatment of AP2IX-5-AID-3HA tagged strain for 30 min, 1 and 2 hr, the differentially expressed genes were 8, 54 and 202, respectively. Among these genes, the significantly downregulated ones were AP2 proteins, inner membrane complex (IMC) proteins and SAG-related proteins. Interestingly, loss of TgAP2IX-5 leads to a defect in internal daughter IMC formation and abnormalities in the morphology of organelles during cell division. Together, our study suggests that TgAP2IX-5 is crucial in regulating IMC formation of daughter cells in T. gondii.
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Affiliation(s)
- Chaoyue Wang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Dandan Hu
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xinming Tang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xingju Song
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Si Wang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Sixin Zhang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Chunhui Duan
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Pei Sun
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jingxia Suo
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Huiming Ma
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xun Suo
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xianyong Liu
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
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24
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The Riveting Cellular Structures of Apicomplexan Parasites. Trends Parasitol 2020; 36:979-991. [PMID: 33011071 DOI: 10.1016/j.pt.2020.09.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/31/2020] [Accepted: 09/03/2020] [Indexed: 12/21/2022]
Abstract
Parasitic protozoa of the phylum Apicomplexa cause a range of human and animal diseases. Their complex life cycles - often heteroxenous with sexual and asexual phases in different hosts - rely on elaborate cytoskeletal structures to enable morphogenesis and motility, organize cell division, and withstand diverse environmental forces. This review primarily focuses on studies using Toxoplasma gondii and Plasmodium spp. as the best studied apicomplexans; however, many cytoskeletal adaptations are broadly conserved and predate the emergence of the parasitic phylum. After decades cataloguing the constituents of such structures, a dynamic picture is emerging of the assembly and maintenance of apicomplexan cytoskeletons, illuminating how they template and orient critical processes during infection. These observations impact our view of eukaryotic diversity and offer future challenges for cell biology.
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25
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Dos Santos Pacheco N, Tosetti N, Koreny L, Waller RF, Soldati-Favre D. Evolution, Composition, Assembly, and Function of the Conoid in Apicomplexa. Trends Parasitol 2020; 36:688-704. [DOI: 10.1016/j.pt.2020.05.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 12/14/2022]
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26
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Gubbels MJ, Keroack CD, Dangoudoubiyam S, Worliczek HL, Paul AS, Bauwens C, Elsworth B, Engelberg K, Howe DK, Coppens I, Duraisingh MT. Fussing About Fission: Defining Variety Among Mainstream and Exotic Apicomplexan Cell Division Modes. Front Cell Infect Microbiol 2020; 10:269. [PMID: 32582569 PMCID: PMC7289922 DOI: 10.3389/fcimb.2020.00269] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 05/06/2020] [Indexed: 12/17/2022] Open
Abstract
Cellular reproduction defines life, yet our textbook-level understanding of cell division is limited to a small number of model organisms centered around humans. The horizon on cell division variants is expanded here by advancing insights on the fascinating cell division modes found in the Apicomplexa, a key group of protozoan parasites. The Apicomplexa display remarkable variation in offspring number, whether karyokinesis follows each S/M-phase or not, and whether daughter cells bud in the cytoplasm or bud from the cortex. We find that the terminology used to describe the various manifestations of asexual apicomplexan cell division emphasizes either the number of offspring or site of budding, which are not directly comparable features and has led to confusion in the literature. Division modes have been primarily studied in two human pathogenic Apicomplexa, malaria-causing Plasmodium spp. and Toxoplasma gondii, a major cause of opportunistic infections. Plasmodium spp. divide asexually by schizogony, producing multiple daughters per division round through a cortical budding process, though at several life-cycle nuclear amplifications stages, are not followed by karyokinesis. T. gondii divides by endodyogeny producing two internally budding daughters per division round. Here we add to this diversity in replication mechanisms by considering the cattle parasite Babesia bigemina and the pig parasite Cystoisospora suis. B. bigemina produces two daughters per division round by a “binary fission” mechanism whereas C. suis produces daughters through both endodyogeny and multiple internal budding known as endopolygeny. In addition, we provide new data from the causative agent of equine protozoal myeloencephalitis (EPM), Sarcocystis neurona, which also undergoes endopolygeny but differs from C. suis by maintaining a single multiploid nucleus. Overall, we operationally define two principally different division modes: internal budding found in cyst-forming Coccidia (comprising endodyogeny and two forms of endopolygeny) and external budding found in the other parasites studied (comprising the two forms of schizogony, binary fission and multiple fission). Progressive insights into the principles defining the molecular and cellular requirements for internal vs. external budding, as well as variations encountered in sexual stages are discussed. The evolutionary pressures and mechanisms underlying apicomplexan cell division diversification carries relevance across Eukaryota.
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Affiliation(s)
- Marc-Jan Gubbels
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Caroline D Keroack
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, United States
| | - Sriveny Dangoudoubiyam
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, KY, United States
| | - Hanna L Worliczek
- Department of Biology, Boston College, Chestnut Hill, MA, United States.,Institute of Parasitology, University of Veterinary Medicine, Vienna, Austria
| | - Aditya S Paul
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, United States
| | - Ciara Bauwens
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Brendan Elsworth
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, United States.,School of Biosciences, University of Melbourne, Melbourne, VIC, Australia
| | - Klemens Engelberg
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Daniel K Howe
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, KY, United States
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, United States
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27
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Dogga SK, Frénal K. Two palmitoyl acyltransferases involved sequentially in the biogenesis of the inner membrane complex of Toxoplasma gondii. Cell Microbiol 2020; 22:e13212. [PMID: 32329212 DOI: 10.1111/cmi.13212] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/16/2020] [Accepted: 04/18/2020] [Indexed: 01/05/2023]
Abstract
The phylum Apicomplexa includes a number of significant human pathogens like Toxoplasma gondii and Plasmodium species. These obligate intracellular parasites possess a membranous structure, the inner membrane complex (IMC), composed of flattened vesicles apposed to the plasma membrane. Numerous proteins associated with the IMC are anchored via a lipid post-translational modification termed palmitoylation. This acylation is catalysed by multi-membrane spanning protein S-acyl-transferases (PATs) containing a catalytic Asp-His-His-Cys (DHHC) motif, commonly referred to as DHHCs. Contrasting the redundancy observed in other organisms, several PATs are essential for T. gondii tachyzoite survival; 2 of them, TgDHHC2 and TgDHHC14 being IMC-resident. Disruption of either of these TgDHHCs results in a rapid collapse of the IMC in the developing daughter cells leading to dramatic morphological defects of the parasites while the impact on the other organelles is limited to their localisation but not to their biogenesis. The acyl-transferase activity of TgDHHC2 and TgDHHC14 is involved sequentially in the formation of the sub-compartments of the IMC. Investigation of proteins known to be palmitoylated and localised to these sub-compartments identified TgISP1/3 as well as TgIAP1/2 to lose their membrane association revealing them as likely substrates of TgDHHC2, while these proteins are not impacted by TgDHHC14 depletion.
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Affiliation(s)
- Sunil Kumar Dogga
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Karine Frénal
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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28
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Ancient MAPK ERK7 is regulated by an unusual inhibitory scaffold required for Toxoplasma apical complex biogenesis. Proc Natl Acad Sci U S A 2020; 117:12164-12173. [PMID: 32409604 PMCID: PMC7275706 DOI: 10.1073/pnas.1921245117] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Apicomplexan parasites include organisms that cause widespread and devastating human diseases such as malaria, cryptosporidiosis, and toxoplasmosis. These parasites are named for a structure, called the “apical complex,” that organizes their invasion and secretory machinery. We found that two proteins, apical cap protein 9 (AC9) and an enzyme called ERK7, work together to facilitate apical complex assembly. Intriguingly, ERK7 is an ancient molecule that is found throughout Eukaryota, though its regulation and function are poorly understood. AC9 is a scaffold that concentrates ERK7 at the base of the developing apical complex. In addition, AC9 binding likely confers substrate selectivity upon ERK7. This simple competitive regulatory model may be a powerful but largely overlooked mechanism throughout biology. Apicomplexan parasites use a specialized cilium structure called the apical complex to organize their secretory organelles and invasion machinery. The apical complex is integrally associated with both the parasite plasma membrane and an intermediate filament cytoskeleton called the inner-membrane complex (IMC). While the apical complex is essential to the parasitic lifestyle, little is known about the regulation of apical complex biogenesis. Here, we identify AC9 (apical cap protein 9), a largely intrinsically disordered component of the Toxoplasma gondii IMC, as essential for apical complex development, and therefore for host cell invasion and egress. Parasites lacking AC9 fail to successfully assemble the tubulin-rich core of their apical complex, called the conoid. We use proximity biotinylation to identify the AC9 interaction network, which includes the kinase extracellular signal-regulated kinase 7 (ERK7). Like AC9, ERK7 is required for apical complex biogenesis. We demonstrate that AC9 directly binds ERK7 through a conserved C-terminal motif and that this interaction is essential for ERK7 localization and function at the apical cap. The crystal structure of the ERK7–AC9 complex reveals that AC9 is not only a scaffold but also inhibits ERK7 through an unusual set of contacts that displaces nucleotide from the kinase active site. ERK7 is an ancient and autoactivating member of the mitogen-activated kinase (MAPK) family and its regulation is poorly understood in all organisms. We propose that AC9 dually regulates ERK7 by scaffolding and concentrating it at its site of action while maintaining it in an “off” state until the specific binding of a true substrate.
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29
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Tosetti N, Dos Santos Pacheco N, Bertiaux E, Maco B, Bournonville L, Hamel V, Guichard P, Soldati-Favre D. Essential function of the alveolin network in the subpellicular microtubules and conoid assembly in Toxoplasma gondii. eLife 2020; 9:56635. [PMID: 32379047 PMCID: PMC7228768 DOI: 10.7554/elife.56635] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 05/06/2020] [Indexed: 12/14/2022] Open
Abstract
The coccidian subgroup of Apicomplexa possesses an apical complex harboring a conoid, made of unique tubulin polymer fibers. This enigmatic organelle extrudes in extracellular invasive parasites and is associated to the apical polar ring (APR). The APR serves as microtubule-organizing center for the 22 subpellicular microtubules (SPMTs) that are linked to a patchwork of flattened vesicles, via an intricate network composed of alveolins. Here, we capitalize on ultrastructure expansion microscopy (U-ExM) to localize the Toxoplasma gondii Apical Cap protein 9 (AC9) and its partner AC10, identified by BioID, to the alveolin network and intercalated between the SPMTs. Parasites conditionally depleted in AC9 or AC10 replicate normally but are defective in microneme secretion and fail to invade and egress from infected cells. Electron microscopy revealed that the mature parasite mutants are conoidless, while U-ExM highlighted the disorganization of the SPMTs which likely results in the catastrophic loss of APR and conoid.
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Affiliation(s)
- Nicolò Tosetti
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Nicolas Dos Santos Pacheco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Eloïse Bertiaux
- Department of Cell Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Bohumil Maco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Lorène Bournonville
- Department of Cell Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Virginie Hamel
- Department of Cell Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Paul Guichard
- Department of Cell Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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30
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May DG, Scott KL, Campos AR, Roux KJ. Comparative Application of BioID and TurboID for Protein-Proximity Biotinylation. Cells 2020; 9:cells9051070. [PMID: 32344865 PMCID: PMC7290721 DOI: 10.3390/cells9051070] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 12/21/2022] Open
Abstract
BioID is a well-established method for identifying protein–protein interactions and has been utilized within live cells and several animal models. However, the conventional labeling period requires 15–18 h for robust biotinylation which may not be ideal for some applications. Recently, two new ligases termed TurboID and miniTurbo were developed using directed evolution of the BioID ligase and were able to produce robust biotinylation following a 10 min incubation with excess biotin. However, there is reported concern about inducibility of biotinylation, cellular toxicity, and ligase stability. To further investigate the practical applications of TurboID and ascertain strengths and weaknesses compared to BioID, we developed several stable cell lines expressing BioID and TurboID fusion proteins and analyzed them via immunoblot, immunofluorescence, and biotin-affinity purification-based proteomics. For TurboID we observed signs of protein instability, persistent biotinylation in the absence of exogenous biotin, and an increase in the practical labeling radius. However, TurboID enabled robust biotinylation in the endoplasmic reticulum lumen compared to BioID. Induction of biotinylation could be achieved by combining doxycycline-inducible expression with growth in biotin depleted culture media. These studies should help inform investigators utilizing BioID-based methods as to the appropriate ligase and experimental protocol for their particular needs.
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Affiliation(s)
- Danielle G. May
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD 57104, USA; (D.G.M.); (K.L.S.)
| | - Kelsey L. Scott
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD 57104, USA; (D.G.M.); (K.L.S.)
| | - Alexandre R. Campos
- Proteomics Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA;
| | - Kyle J. Roux
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD 57104, USA; (D.G.M.); (K.L.S.)
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57105, USA
- Correspondence: ; Tel.: +1-605-312-6418
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31
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Boothroyd JC. What a Difference 30 Years Makes! A Perspective on Changes in Research Methodologies Used to Study Toxoplasma gondii. Methods Mol Biol 2020; 2071:1-25. [PMID: 31758444 DOI: 10.1007/978-1-4939-9857-9_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Toxoplasma gondii is a remarkable species with a rich cell, developmental, and population biology. It is also sometimes responsible for serious disease in animals and humans and the stages responsible for such disease are relatively easy to study in vitro or in laboratory animal models. As a result of all this, Toxoplasma has become the subject of intense investigation over the last several decades, becoming a model organism for the study of the phylum of which it is a member, Apicomplexa. This has led to an ever-growing number of investigators applying an ever-expanding set of techniques to dissecting how Toxoplasma "ticks" and how it interacts with its many hosts. In this perspective piece I first wind back the clock 30 years and then trace the extraordinary pace of methodologies that have propelled the field forward to where we are today. In keeping with the theme of this collection, I focus almost exclusively on the parasite, rather than host side of the equation. I finish with a few thoughts about where the field might be headed-though if we have learned anything, the only sure prediction is that the pace of technological advance will surely continue to accelerate and the future will give us still undreamed of methods for taking apart (and then putting back together) this amazing organism with all its intricate biology. We have so far surely just scratched the surface.
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Affiliation(s)
- John C Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA.
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32
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Hammarton TC. Who Needs a Contractile Actomyosin Ring? The Plethora of Alternative Ways to Divide a Protozoan Parasite. Front Cell Infect Microbiol 2019; 9:397. [PMID: 31824870 PMCID: PMC6881465 DOI: 10.3389/fcimb.2019.00397] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/06/2019] [Indexed: 01/21/2023] Open
Abstract
Cytokinesis, or the division of the cytoplasm, following the end of mitosis or meiosis, is accomplished in animal cells, fungi, and amoebae, by the constriction of an actomyosin contractile ring, comprising filamentous actin, myosin II, and associated proteins. However, despite this being the best-studied mode of cytokinesis, it is restricted to the Opisthokonta and Amoebozoa, since members of other evolutionary supergroups lack myosin II and must, therefore, employ different mechanisms. In particular, parasitic protozoa, many of which cause significant morbidity and mortality in humans and animals as well as considerable economic losses, employ a wide diversity of mechanisms to divide, few, if any, of which involve myosin II. In some cases, cell division is not only myosin II-independent, but actin-independent too. Mechanisms employed range from primitive mechanical cell rupture (cytofission), to motility- and/or microtubule remodeling-dependent mechanisms, to budding involving the constriction of divergent contractile rings, to hijacking host cell division machinery, with some species able to utilize multiple mechanisms. Here, I review current knowledge of cytokinesis mechanisms and their molecular control in mammalian-infective parasitic protozoa from the Excavata, Alveolata, and Amoebozoa supergroups, highlighting their often-underappreciated diversity and complexity. Billions of people and animals across the world are at risk from these pathogens, for which vaccines and/or optimal treatments are often not available. Exploiting the divergent cell division machinery in these parasites may provide new avenues for the treatment of protozoal disease.
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Affiliation(s)
- Tansy C Hammarton
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
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33
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Choi CP, Moon AS, Back PS, Jami‐Alahmadi Y, Vashisht AA, Wohlschlegel JA, Bradley PJ. A photoactivatable crosslinking system reveals protein interactions in the Toxoplasma gondii inner membrane complex. PLoS Biol 2019; 17:e3000475. [PMID: 31584943 PMCID: PMC6795473 DOI: 10.1371/journal.pbio.3000475] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/16/2019] [Accepted: 09/13/2019] [Indexed: 11/18/2022] Open
Abstract
The Toxoplasma gondii inner membrane complex (IMC) is an important organelle involved in parasite motility and replication. The IMC resides beneath the parasite’s plasma membrane and is composed of both membrane and cytoskeletal components. Although the protein composition of the IMC is becoming better understood, the protein–protein associations that enable proper functioning of the organelle remain largely unknown. Determining protein interactions in the IMC cytoskeletal network is particularly challenging, as disrupting the cytoskeleton requires conditions that disrupt protein complexes. To circumvent this problem, we demonstrate the application of a photoreactive unnatural amino acid (UAA) crosslinking system to capture protein interactions in the native intracellular environment. In addition to identifying binding partners, the UAA approach maps the binding interface of the bait protein used for crosslinking, providing structural information of the interacting proteins. We apply this technology to the essential IMC protein ILP1 and demonstrate that distinct regions of its C-terminal coiled-coil domain crosslink to the alveolins IMC3 and IMC6, as well as IMC27. We also show that the IMC3 C-terminal domain and the IMC6 N-terminal domain are necessary for binding to ILP1, further mapping interactions between ILP1 and the cytoskeleton. Together, this study develops a new approach to study protein–protein interactions in Toxoplasma and provides the first insight into the architecture of the cytoskeletal network of the apicomplexan IMC. The inner membrane complex of the human parasite Toxoplasma gondii is an important organelle involved in motility and replication. This study expands the genetic code of Toxoplasma, allowing the use of photoactivatable unnatural amino acids to uncover interactions within the apicomplexan inner membrane complex.
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Affiliation(s)
- Charles Paul Choi
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Andy Seong Moon
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Peter Sungmin Back
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Yasaman Jami‐Alahmadi
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Ajay Amar Vashisht
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - James Akira Wohlschlegel
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Peter John Bradley
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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34
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Engelberg K, Chen CT, Bechtel T, Sánchez Guzmán V, Drozda AA, Chavan S, Weerapana E, Gubbels MJ. The apical annuli of Toxoplasma gondii are composed of coiled-coil and signalling proteins embedded in the inner membrane complex sutures. Cell Microbiol 2019; 22:e13112. [PMID: 31470470 DOI: 10.1111/cmi.13112] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 07/16/2019] [Accepted: 08/15/2019] [Indexed: 02/06/2023]
Abstract
The apical annuli are among the most intriguing and understudied structures in the cytoskeleton of the apicomplexan parasite Toxoplasma gondii. We mapped the proteome of the annuli in Toxoplasma by reciprocal proximity biotinylation (BioID), and validated five apical annuli proteins (AAP1-5), Centrin2, and an apical annuli methyltransferase. Moreover, inner membrane complex (IMC) suture proteins connecting the alveolar vesicles were also detected and support annuli residence within the sutures. Super-resolution microscopy identified a concentric organisation comprising four rings with diameters ranging from 200 to 400 nm. The high prevalence of domain signatures shared with centrosomal proteins in the AAPs together with Centrin2 suggests that the annuli are related and/or derived from the centrosomes. Phylogenetic analysis revealed that the AAPs are conserved narrowly in coccidian, apicomplexan parasites that multiply by an internal budding mechanism. This suggests a role in replication, for example, to provide pores in the mother IMC permitting exchange of building blocks and waste products. However, presence of multiple signalling domains and proteins are suggestive of additional functions. Knockout of AAP4, the most conserved compound forming the largest ring-like structure, modestly decreased parasite fitness in vitro but had no significant impact on acute virulence in vivo. In conclusion, the apical annuli are composed of coiled-coil and signalling proteins assembled in a pore-like structure crossing the IMC barrier maintained during internal budding.
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Affiliation(s)
| | - Chun-Ti Chen
- Department of Biology, Boston College, Chestnut Hill, Massachusetts.,Precision Medicine Center, Department of Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Tyler Bechtel
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts
| | - Victoria Sánchez Guzmán
- Department of Biology, Boston College, Chestnut Hill, Massachusetts.,Department of Biology, University of Puerto Rico, San Juan, Puerto Rico
| | - Allison A Drozda
- Department of Biology, Boston College, Chestnut Hill, Massachusetts
| | - Suyog Chavan
- Department of Biology, Boston College, Chestnut Hill, Massachusetts
| | | | - Marc-Jan Gubbels
- Department of Biology, Boston College, Chestnut Hill, Massachusetts
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35
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Yang C, Broncel M, Dominicus C, Sampson E, Blakely WJ, Treeck M, Arrizabalaga G. A plasma membrane localized protein phosphatase in Toxoplasma gondii, PPM5C, regulates attachment to host cells. Sci Rep 2019; 9:5924. [PMID: 30976120 PMCID: PMC6459975 DOI: 10.1038/s41598-019-42441-1] [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: 12/27/2018] [Accepted: 03/25/2019] [Indexed: 11/17/2022] Open
Abstract
The propagation of Toxoplasma gondii is accomplished by repeated lytic cycles of parasite attachment to a host cell, invasion, replication within a parasitophorous vacuole, and egress from the cell. This lytic cycle is delicately regulated by calcium-dependent reversible phosphorylation of the molecular machinery that drives invasion and egress. While much progress has been made elucidating the protein kinases and substrates central to parasite propagation, little is known about the relevant protein phosphatases. In this study, we focused on the five protein phosphatases that are predicted to be membrane-associated either integrally or peripherally. We have determined that of these only PPM5C, a PP2C family member, localizes to the plasma membrane of Toxoplasma. Disruption of PPM5C results in a slow propagation phenotype in tissue culture. Interestingly, parasites lacking PPM5C divide and undergo egress at a normal rate, but have a deficiency in attaching to host cells. Both membrane localization and phosphatase activity are required for PPM5C’s role in attachment. Phosphoproteomic analysis show relatively few phosphorylation sites being affected by PPM5C deletion in extracellular parasites of which several are found on proteins involved in signaling cascades. This implies that PPM5C is part of a wider regulatory network important for attachment to host cells.
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Affiliation(s)
- Chunlin Yang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Malgorzata Broncel
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Caia Dominicus
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Emily Sampson
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - William J Blakely
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Gustavo Arrizabalaga
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA. .,Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA.
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36
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The dense granule protein 8 (GRA8) is a component of the sub-pellicular cytoskeleton in Toxoplasma gondii. Parasitol Res 2019; 118:1899-1918. [PMID: 30949853 DOI: 10.1007/s00436-019-06298-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/18/2019] [Indexed: 12/24/2022]
Abstract
After host cell invasion, Toxoplasma secretes a variety of dense granule proteins (GRA proteins) from its secretory dense granules, which are involved in the biogenesis of the parasitophorous vacuole (PV). TgGRA8I is predicted to contain proline-rich domains, which are structural features of some cytoskeleton-related proteins. In agreement with this observation, previous proteomic analyses revealed the presence of TgGRA8I in the Toxoplasma sub-pellicular cytoskeleton. In the present study, we show (1) by docking analyses that TgGRA8I may interact with both Toxoplasma β-tubulin and actin; (2) by immunoelectron microscopy, proteomic, biochemical, and cellular approaches that TgGRA8I associates with sub-pellicular microtubules and actin at the parasite sub-pellicular cytoskeleton; (3) that type I parasites (RH strain) lacking the GRA8 gene (RHΔku80Δgra8) exhibit loss of conoid extrusion, diminished cell infection, and egress capabilities, and that these motility impairments were likely due to important alterations in their sub-pellicular cytoskeleton, in particular their sub-pellicular microtubules and meshwork. Parasites lacking the GRA4 gene (RHΔku80Δgra4) did not show modifications in the organization of the sub-pellicular cytoskeleton. Collectively, these results demonstrated that TgGRA8I is a dense granule protein that, besides its role in the formation of the PV, contributes to the organization of the parasite sub-pellicular cytoskeleton and motility. This is the first proline-rich protein described in the Toxoplasma cytoskeleton, which is a key organelle for both the parasite motility and the invasion process. Knowledge about the function of cytoskeleton components in Toxoplasma is fundamental to understand the motility process and the host cell invasion mechanism. Refining this knowledge should lead to the design of novel pharmacological strategies for the treatment against toxoplasmosis.
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37
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Harding CR, Gow M, Kang JH, Shortt E, Manalis SR, Meissner M, Lourido S. Alveolar proteins stabilize cortical microtubules in Toxoplasma gondii. Nat Commun 2019; 10:401. [PMID: 30674885 PMCID: PMC6344517 DOI: 10.1038/s41467-019-08318-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 01/04/2019] [Indexed: 12/21/2022] Open
Abstract
Single-celled protists use elaborate cytoskeletal structures, including arrays of microtubules at the cell periphery, to maintain polarity and rigidity. The obligate intracellular parasite Toxoplasma gondii has unusually stable cortical microtubules beneath the alveoli, a network of flattened membrane vesicles that subtends the plasmalemma. However, anchoring of microtubules along alveolar membranes is not understood. Here, we show that GAPM1a, an integral membrane protein of the alveoli, plays a role in maintaining microtubule stability. Degradation of GAPM1a causes cortical microtubule disorganisation and subsequent depolymerisation. These changes in the cytoskeleton lead to parasites becoming shorter and rounder, which is accompanied by a decrease in cellular volume. Extended GAPM1a depletion leads to severe defects in division, reminiscent of the effect of disrupting other alveolar proteins. We suggest that GAPM proteins link the cortical microtubules to the alveoli and are required to maintain the shape and rigidity of apicomplexan zoites. Cortical microtubules of Toxoplasma gondii are exceptionally stable, but it isn’t known how they are anchored along membranes. Here, Harding et al. show that GAPM proteins localize to the inner membrane complex and are essential for maintaining the structural stability of parasites.
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Affiliation(s)
- Clare R Harding
- Whitehead Institute for Biomedical Research, Cambridge, 02142, MA, USA.
| | - Matthew Gow
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - Joon Ho Kang
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Emily Shortt
- Whitehead Institute for Biomedical Research, Cambridge, 02142, MA, USA
| | - Scott R Manalis
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA.,Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Markus Meissner
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, G12 8TA, UK.,Department of Veterinary Sciences, Ludwig-Maximilians-Universität, Munich, 80539, Germany
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, 02142, MA, USA. .,Biology Department, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA.
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38
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Goodenough U, Roth R, Kariyawasam T, He A, Lee JH. Epiplasts: Membrane Skeletons and Epiplastin Proteins in Euglenids, Glaucophytes, Cryptophytes, Ciliates, Dinoflagellates, and Apicomplexans. mBio 2018; 9:e02020-18. [PMID: 30377285 PMCID: PMC6212826 DOI: 10.1128/mbio.02020-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 01/03/2023] Open
Abstract
Animals and amoebae assemble actin/spectrin-based plasma membrane skeletons, forming what is often called the cell cortex, whereas euglenids and alveolates (ciliates, dinoflagellates, and apicomplexans) have been shown to assemble a thin, viscoelastic, actin/spectrin-free membrane skeleton, here called the epiplast. Epiplasts include a class of proteins, here called the epiplastins, with a head/medial/tail domain organization, whose medial domains have been characterized in previous studies by their low-complexity amino acid composition. We have identified two additional features of the medial domains: a strong enrichment of acid/base amino acid dyads and a predicted β-strand/random coil secondary structure. These features have served to identify members in two additional unicellular eukaryotic radiations-the glaucophytes and cryptophytes-as well as additional members in the alveolates and euglenids. We have analyzed the amino acid composition and domain structure of 219 epiplastin sequences and have used quick-freeze deep-etch electron microscopy to visualize the epiplasts of glaucophytes and cryptophytes. We define epiplastins as proteins encoded in organisms that assemble epiplasts, but epiplastin-like proteins, of unknown function, are also encoded in Insecta, Basidiomycetes, and Caulobacter genomes. We discuss the diverse cellular traits that are supported by epiplasts and propose evolutionary scenarios that are consonant with their distribution in extant eukaryotes.IMPORTANCE Membrane skeletons associate with the inner surface of the plasma membrane to provide support for the fragile lipid bilayer and an elastic framework for the cell itself. Several radiations, including animals, organize such skeletons using actin/spectrin proteins, but four major radiations of eukaryotic unicellular organisms, including disease-causing parasites such as Plasmodium, have been known to construct an alternative and essential skeleton (the epiplast) using a class of proteins that we term epiplastins. We have identified epiplastins in two additional radiations and present images of their epiplasts using electron microscopy. We analyze the sequences and secondary structure of 219 epiplastins and present an in-depth overview and analysis of their known and posited roles in cellular organization and parasite infection. An understanding of epiplast assembly may suggest therapeutic approaches to combat infectious agents such as Plasmodium as well as approaches to the engineering of useful viscoelastic biofilms.
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Affiliation(s)
- Ursula Goodenough
- Department of Biology, Washington University, St. Louis, Missouri, USA
| | - Robyn Roth
- Center for Cellular Imaging, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Thamali Kariyawasam
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amelia He
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jae-Hyeok Lee
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
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39
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Branon TC, Bosch JA, Sanchez AD, Udeshi ND, Svinkina T, Carr SA, Feldman JL, Perrimon N, Ting AY. Efficient proximity labeling in living cells and organisms with TurboID. Nat Biotechnol 2018; 36:880-887. [PMID: 30125270 PMCID: PMC6126969 DOI: 10.1038/nbt.4201] [Citation(s) in RCA: 922] [Impact Index Per Article: 153.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 07/02/2018] [Indexed: 12/11/2022]
Abstract
Protein interaction networks and protein compartmentalization underlie all signaling and regulatory processes in cells. Enzyme-catalyzed proximity labeling (PL) has emerged as a new approach to study the spatial and interaction characteristics of proteins in living cells. However, current PL methods require over 18 h of labeling time or utilize chemicals with limited cell permeability or high toxicity. We used yeast display-based directed evolution to engineer two promiscuous mutants of biotin ligase, TurboID and miniTurbo, which catalyze PL with much greater efficiency than BioID or BioID2, and enable 10-min PL in cells with non-toxic and easily deliverable biotin. Furthermore, TurboID extends biotin-based PL to flies and worms.
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Affiliation(s)
- Tess C. Branon
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Departments of Genetics, Stanford University, Stanford, California, USA
- Departments of Chemistry, Stanford University, Stanford, California, USA
- Department of Biology, Stanford University, Stanford, California, USA
| | - Justin A. Bosch
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Ariana D. Sanchez
- Department of Biology, Stanford University, Stanford, California, USA
| | | | - Tanya Svinkina
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Steven A. Carr
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | | | - Norbert Perrimon
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Boston, Massachusetts, USA
| | - Alice Y. Ting
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Departments of Genetics, Stanford University, Stanford, California, USA
- Departments of Chemistry, Stanford University, Stanford, California, USA
- Department of Biology, Stanford University, Stanford, California, USA
- Howard Hughes Medical Institute, Boston, Massachusetts, USA
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40
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Boucher MJ, Ghosh S, Zhang L, Lal A, Jang SW, Ju A, Zhang S, Wang X, Ralph SA, Zou J, Elias JE, Yeh E. Integrative proteomics and bioinformatic prediction enable a high-confidence apicoplast proteome in malaria parasites. PLoS Biol 2018; 16:e2005895. [PMID: 30212465 PMCID: PMC6155542 DOI: 10.1371/journal.pbio.2005895] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 09/25/2018] [Accepted: 08/28/2018] [Indexed: 12/20/2022] Open
Abstract
Malaria parasites (Plasmodium spp.) and related apicomplexan pathogens contain a nonphotosynthetic plastid called the apicoplast. Derived from an unusual secondary eukaryote-eukaryote endosymbiosis, the apicoplast is a fascinating organelle whose function and biogenesis rely on a complex amalgamation of bacterial and algal pathways. Because these pathways are distinct from the human host, the apicoplast is an excellent source of novel antimalarial targets. Despite its biomedical importance and evolutionary significance, the absence of a reliable apicoplast proteome has limited most studies to the handful of pathways identified by homology to bacteria or primary chloroplasts, precluding our ability to study the most novel apicoplast pathways. Here, we combine proximity biotinylation-based proteomics (BioID) and a new machine learning algorithm to generate a high-confidence apicoplast proteome consisting of 346 proteins. Critically, the high accuracy of this proteome significantly outperforms previous prediction-based methods and extends beyond other BioID studies of unique parasite compartments. Half of identified proteins have unknown function, and 77% are predicted to be important for normal blood-stage growth. We validate the apicoplast localization of a subset of novel proteins and show that an ATP-binding cassette protein ABCF1 is essential for blood-stage survival and plays a previously unknown role in apicoplast biogenesis. These findings indicate critical organellar functions for newly discovered apicoplast proteins. The apicoplast proteome will be an important resource for elucidating unique pathways derived from secondary endosymbiosis and prioritizing antimalarial drug targets.
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Affiliation(s)
- Michael J. Boucher
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
| | - Sreejoyee Ghosh
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
| | - Lichao Zhang
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Avantika Lal
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Se Won Jang
- Department of Computer Science, Stanford University, Stanford, California, United States of America
| | - An Ju
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Shuying Zhang
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Xinzi Wang
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Stuart A. Ralph
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Vic, Australia
| | - James Zou
- Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, California, United States of America
- Chan Zuckerberg Biohub, San Francisco, California, United States of America
| | - Joshua E. Elias
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Ellen Yeh
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
- Chan Zuckerberg Biohub, San Francisco, California, United States of America
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41
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Long S, Brown KM, Sibley LD. CRISPR-mediated Tagging with BirA Allows Proximity Labeling in Toxoplasma gondii. Bio Protoc 2018; 8:e2768. [PMID: 29644258 DOI: 10.21769/bioprotoc.2768] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Defining protein interaction networks can provide key insights into how protein complexes govern complex biological problems. Here we define a method for proximity based labeling using permissive biotin ligase to define protein networks in the intracellular parasite Toxoplasma gondii. When combined with CRISPR/Cas9 based tagging, this method provides a robust approach to defining protein networks. This approach detects interaction within intact cells, it is applicable to both soluble and insoluble components, including large proteins complexes that interact with the cytoskeleton and unique microtubule organizing center that comprises the apical complex in apicomplexan parasites.
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Affiliation(s)
- Shaojun Long
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Kevin M Brown
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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42
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LaFavers KA, Márquez Nogueras KM, Coppens I, Moreno SN, Arrizabalaga G. A novel dense granule protein, GRA41, regulates timing of egress and calcium sensitivity in Toxoplasma gondii. Cell Microbiol 2017; 19:10.1111/cmi.12749. [PMID: 28436089 PMCID: PMC5787377 DOI: 10.1111/cmi.12749] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/06/2017] [Accepted: 04/16/2017] [Indexed: 12/31/2022]
Abstract
Toxoplasma gondii is an obligate intracellular apicomplexan parasite with high seroprevalence in humans. Repeated lytic cycles of invasion, replication, and egress drive both the propagation and the virulence of this parasite. Key steps in this cycle, including invasion and egress, depend on tightly regulated calcium fluxes and, although many of the calcium-dependent effectors have been identified, the factors that detect and regulate the calcium fluxes are mostly unknown. To address this knowledge gap, we used a forward genetic approach to isolate mutants resistant to extracellular exposure to the calcium ionophore A23187. Through whole genome sequencing and complementation, we have determined that a nonsense mutation in a previously uncharacterised protein is responsible for the ionophore resistance of one of the mutants. The complete loss of this protein recapitulates the resistance phenotype and importantly shows defects in calcium regulation and in the timing of egress. The affected protein, GRA41, localises to the dense granules and is secreted into the parasitophorous vacuole where it associates with the tubulovesicular network. Our findings support a connection between the tubulovesicular network and ion homeostasis within the parasite, and thus a novel role for the vacuole of this important pathogen.
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Affiliation(s)
- Kaice A. LaFavers
- Department of Pharmacology and Toxicology, Indiana University School of Medicine
| | | | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Indiana University School of Medicine, Departments of Pharmacology and Toxicology and Microbiology and Immunology, Indianapolis, IN, USA
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