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Maclean AE, Sloan MA, Renaud EA, Argyle BE, Lewis WH, Ovciarikova J, Demolombe V, Waller RF, Besteiro S, Sheiner L. The Toxoplasma gondii mitochondrial transporter ABCB7L is essential for the biogenesis of cytosolic and nuclear iron-sulfur cluster proteins and cytosolic translation. mBio 2024:e0087224. [PMID: 39207139 DOI: 10.1128/mbio.00872-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 07/26/2024] [Indexed: 09/04/2024] Open
Abstract
Iron-sulfur (Fe-S) clusters are ubiquitous inorganic cofactors required for numerous essential cellular pathways. Since they cannot be scavenged from the environment, Fe-S clusters are synthesized de novo in cellular compartments such as the apicoplast, mitochondrion, and cytosol. The cytosolic Fe-S cluster biosynthesis pathway relies on the transport of an intermediate from the mitochondrial pathway. An ATP-binding cassette (ABC) transporter called ABCB7 is responsible for this role in numerous commonly studied organisms, but its role in the medically important apicomplexan parasites has not yet been studied. Here we identify and characterize a Toxoplasma gondii ABCB7 homolog, which we name ABCB7-like (ABCB7L). Genetic depletion shows that it is essential for parasite growth and that its disruption triggers partial stage conversion. Characterization of the knock-down line highlights a defect in the biogenesis of cytosolic and nuclear Fe-S proteins leading to defects in protein translation and other pathways including DNA and RNA replication and metabolism. Our work provides support for a broad conservation of the connection between mitochondrial and cytosolic pathways in Fe-S cluster biosynthesis and reveals its importance for parasite survival. IMPORTANCE Iron-sulfur (Fe-S) clusters are inorganic cofactors of proteins that play key roles in numerous essential biological processes, for example, respiration and DNA replication. Cells possess dedicated biosynthetic pathways to assemble Fe-S clusters, including a pathway in the mitochondrion and cytosol. A single transporter, called ABCB7, connects these two pathways, allowing an essential intermediate generated by the mitochondrial pathway to be used in the cytosolic pathway. Cytosolic and nuclear Fe-S proteins are dependent on the mitochondrial pathway, mediated by ABCB7, in numerous organisms studied to date. Here, we study the role of a homolog of ABCB7, which we name ABCB7-like (ABCB7L), in the ubiquitous unicellular apicomplexan parasite Toxoplasma gondii. We generated a depletion mutant of Toxoplasma ABCB7L and showed its importance for parasite fitness. Using comparative quantitative proteomic analysis and experimental validation of the mutants, we show that ABCB7L is required for cytosolic and nuclear, but not mitochondrial, Fe-S protein biogenesis. Our study supports the conservation of a protein homologous to ABCB7 and which has a similar function in apicomplexan parasites and provides insight into an understudied aspect of parasite metabolism.
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Affiliation(s)
- Andrew E Maclean
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
- School of Infection and Immunity, University of Glasgow, Glasgow, United Kingdom
| | - Megan A Sloan
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
- School of Infection and Immunity, University of Glasgow, Glasgow, United Kingdom
| | - Eléa A Renaud
- LPHI, Univ Montpellier, CNRS, INSERM, Montpellier, France
| | - Blythe E Argyle
- School of Infection and Immunity, University of Glasgow, Glasgow, United Kingdom
| | - William H Lewis
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Jana Ovciarikova
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
- School of Infection and Immunity, University of Glasgow, Glasgow, United Kingdom
| | - Vincent Demolombe
- IPSiM, Univ Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Ross F Waller
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | | | - Lilach Sheiner
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
- School of Infection and Immunity, University of Glasgow, Glasgow, United Kingdom
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2
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Li ZH, Asady B, Chang L, Hortua Triana MA, Li C, Coppens I, Moreno SNJ. Calcium tunneling through the ER and transfer to other organelles for optimal signaling in Toxoplasma gondii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.15.608087. [PMID: 39185237 PMCID: PMC11343207 DOI: 10.1101/2024.08.15.608087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Ca 2+ signaling in cells begins with the opening of Ca 2+ channels in either the plasma membrane (PM) or the endoplasmic reticulum (ER) and results in a dramatic increase in the physiologically low (<100 nM) cytosolic Ca 2+ level. The temporal and spatial Ca 2+ levels are well regulated to enable precise and specific activation of critical biological processes. Ca 2+ signaling regulates pathogenic features of apicomplexan parasites like Toxoplasma gondii which infects approximately one-third of the world's population. T. gondii relies on Ca 2+ signals to stimulate traits of its infection cycle and several Ca 2+ signaling elements play essential roles in its parasitic cycle. Active egress, an essential step for the infection cycle of T. gondii is preceded by a large increase in cytosolic Ca 2+ most likely by release from intracellular stores. Intracellular parasites take up Ca 2+ from the host cell during host Ca 2+ signaling events to replenish intracellular stores. In this work, we investigated the mechanism by which intracellular stores are replenished with Ca 2+ and demonstrated a central role for the SERCA-Ca 2+ -ATPase to keep not only the ER filled with Ca 2+ but also acidic stores. We also show mitochondrial Ca 2+ uptake, by transfer of Ca 2+ from the ER most likely through membrane contact sites. We propose a central role for the ER in tunneling of calcium from the extracellular milieu through the ER to other organelles. HIGHLIGHTS The T. gondii ER efficiently takes up Ca 2+ that enters the cytosol from the extracellular milieu. Filling of acidic stores in T. gondii appears to be dependent on the filling of the ER The mitochondrion of T. gondii has no direct access to extracellular calcium but is able to take up Ca 2+ by transfer from the ER and/or acidic stores.
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3
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Usey MM, Ruberto AA, Huet D. The Toxoplasma gondii homolog of ATPase inhibitory factor 1 is critical for mitochondrial cristae maintenance and stress response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.09.607411. [PMID: 39149366 PMCID: PMC11326266 DOI: 10.1101/2024.08.09.607411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
The production of energy in the form of ATP by the mitochondrial ATP synthase must be tightly controlled. One well-conserved form of regulation is mediated via ATPase inhibitory factor 1 (IF1), which governs ATP synthase activity and gene expression patterns through a cytoprotective process known as mitohormesis. In apicomplexans, the processes regulating ATP synthase activity are not fully elucidated. Using the model apicomplexan Toxoplasma gondii, we found that knockout and overexpression of TgIF1, the structural homolog of IF1, significantly affected gene expression. Additionally, TgIF1 overexpression resulted in the formation of a stable TgIF1 oligomer that increased the presence of higher order ATP synthase oligomers. We also show that parasites lacking TgIF1 exhibit reduced mitochondrial cristae density, and that while TgIF1 levels do not affect growth in conventional culture conditions, they are crucial for parasite survival under hypoxia. Interestingly, TgIF1 overexpression enhances recovery from oxidative stress, suggesting a mitohormetic function. In summary, while TgIF1 does not appear to play a role in metabolic regulation under conventional growth conditions, our work highlights its importance for adapting to stressors faced by T. gondii and other apicomplexans throughout their intricate life cycles.
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Affiliation(s)
- Madelaine M. Usey
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Anthony A. Ruberto
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | - Diego Huet
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA, USA
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
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4
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Zwahlen SM, Hayward JA, Maguire CS, Qin AR, van Dooren GG. A myzozoan-specific protein is an essential membrane-anchoring component of the succinate dehydrogenase complex in Toxoplasma parasites. Open Biol 2024; 14:230463. [PMID: 38835243 DOI: 10.1098/rsob.230463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 01/15/2024] [Indexed: 06/06/2024] Open
Abstract
Succinate dehydrogenase (SDH) is a protein complex that functions in the tricarboxylic acid cycle and the electron transport chain of mitochondria. In most eukaryotes, SDH is highly conserved and comprises the following four subunits: SdhA and SdhB form the catalytic core of the complex, while SdhC and SdhD anchor the complex in the membrane. Toxoplasma gondii is an apicomplexan parasite that infects one-third of humans worldwide. The genome of T. gondii encodes homologues of the catalytic subunits SdhA and SdhB, although the physiological role of the SDH complex in the parasite and the identity of the membrane-anchoring subunits are poorly understood. Here, we show that the SDH complex contributes to optimal proliferation and O2 consumption in the disease-causing tachyzoite stage of the T. gondii life cycle. We characterize a small membrane-bound subunit of the SDH complex called mitochondrial protein ookinete developmental defect (MPODD), which is conserved among myzozoans, a phylogenetic grouping that incorporates apicomplexan parasites and their closest free-living relatives. We demonstrate that TgMPODD is essential for SDH activity and plays a key role in attaching the TgSdhA and TgSdhB proteins to the membrane anchor of the complex. Our findings highlight a unique and important feature of mitochondrial energy metabolism in apicomplexan parasites and their relatives.
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Affiliation(s)
- Soraya M Zwahlen
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
| | - Jenni A Hayward
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
| | - Capella S Maguire
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
| | - Alex R Qin
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
| | - Giel G van Dooren
- Research School of Biology, Australian National University , Canberra, Australian Capital Territory, Australia
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5
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Hawkins LM, Wang C, Chaput D, Batra M, Marsilia C, Awshah D, Suvorova ES. The Crk4-Cyc4 complex regulates G 2/M transition in Toxoplasma gondii. EMBO J 2024; 43:2094-2126. [PMID: 38600241 PMCID: PMC11148040 DOI: 10.1038/s44318-024-00095-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/12/2024] [Accepted: 03/26/2024] [Indexed: 04/12/2024] Open
Abstract
A versatile division of apicomplexan parasites and a dearth of conserved regulators have hindered the progress of apicomplexan cell cycle studies. While most apicomplexans divide in a multinuclear fashion, Toxoplasma gondii tachyzoites divide in the traditional binary mode. We previously identified five Toxoplasma CDK-related kinases (Crk). Here, we investigated TgCrk4 and its cyclin partner TgCyc4. We demonstrated that TgCrk4 regulates conventional G2 phase processes, such as repression of chromosome rereplication and centrosome reduplication, and acts upstream of the spindle assembly checkpoint. The spatial TgCyc4 dynamics supported the TgCrk4-TgCyc4 complex role in the coordination of chromosome and centrosome cycles. We also identified a dominant TgCrk4-TgCyc4 complex interactor, TgiRD1 protein, related to DNA replication licensing factor CDT1 but played no role in licensing DNA replication in the G1 phase. Our results showed that TgiRD1 also plays a role in controlling chromosome and centrosome reduplication. Global phosphoproteome analyses identified TgCrk4 substrates, including TgORC4, TgCdc20, TgGCP2, and TgPP2ACA. Importantly, the phylogenetic and structural studies suggest the Crk4-Cyc4 complex is limited to a minor group of the binary dividing apicomplexans.
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Affiliation(s)
- Lauren M Hawkins
- Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Chengqi Wang
- College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Dale Chaput
- Proteomics Core, College of Arts and Sciences, University of South Florida, Tampa, FL, 33612, USA
| | - Mrinalini Batra
- Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Clem Marsilia
- Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Danya Awshah
- Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Elena S Suvorova
- Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
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6
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Baptista CG, Hosking S, Gas-Pascual E, Ciampossine L, Abel S, Hakimi MA, Jeffers V, Le Roch K, West CM, Blader IJ. The Toxoplasma gondii F-Box Protein L2 Functions as a Repressor of Stage Specific Gene Expression. PLoS Pathog 2024; 20:e1012269. [PMID: 38814984 PMCID: PMC11166348 DOI: 10.1371/journal.ppat.1012269] [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: 12/18/2023] [Revised: 06/11/2024] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
Toxoplasma gondii is a foodborne pathogen that can cause severe and life-threatening infections in fetuses and immunocompromised patients. Felids are its only definitive hosts, and a wide range of animals, including humans, serve as intermediate hosts. When the transmissible bradyzoite stage is orally ingested by felids, they transform into merozoites that expand asexually, ultimately generating millions of gametes for the parasite sexual cycle. However, bradyzoites in intermediate hosts differentiate exclusively to disease-causing tachyzoites, which rapidly disseminate throughout the host. Though tachyzoites are well-studied, the molecular mechanisms governing transitioning between developmental stages are poorly understood. Each parasite stage can be distinguished by a characteristic transcriptional signature, with one signature being repressed during the other stages. Switching between stages require substantial changes in the proteome, which is achieved in part by ubiquitination. F-box proteins mediate protein poly-ubiquitination by recruiting substrates to SKP1, Cullin-1, F-Box protein E3 ubiquitin ligase (SCF-E3) complexes. We have identified an F-box protein named Toxoplasma gondii F-Box Protein L2 (TgFBXL2), which localizes to distinct perinucleolar sites. TgFBXL2 is stably engaged in an SCF-E3 complex that is surprisingly also associated with a COP9 signalosome complex that negatively regulates SCF-E3 function. At the cellular level, TgFBXL2-depleted parasites are severely defective in centrosome replication and daughter cell development. Most remarkable, RNAseq data show that TgFBXL2 conditional depletion induces the expression of stage-specific genes including a large cohort of genes necessary for sexual commitment. Together, these data suggest that TgFBXL2 is a latent guardian of stage specific gene expression in Toxoplasma and poised to remove conflicting proteins in response to an unknown trigger of development.
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Affiliation(s)
- Carlos G. Baptista
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
| | - Sarah Hosking
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
| | - Elisabet Gas-Pascual
- Department of Biochemistry & Molecular Biology, Center for Tropical & Emerging Global Diseases, University of Georgia, Athens, Georgia United States of America
| | - Loic Ciampossine
- Department of Molecular, Cell, and Systems Biology, University of California Riverside, Riverside, California, United States of America
| | - Steven Abel
- Department of Molecular, Cell, and Systems Biology, University of California Riverside, Riverside, California, United States of America
| | - Mohamed-Ali Hakimi
- Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences (IAB), INSERM U1209, CNRS UMR 5309, Grenoble Alpes University, Grenoble, France
| | - Victoria Jeffers
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Karine Le Roch
- Department of Molecular, Cell, and Systems Biology, University of California Riverside, Riverside, California, United States of America
| | - Christopher M. West
- Department of Biochemistry & Molecular Biology, Center for Tropical & Emerging Global Diseases, University of Georgia, Athens, Georgia United States of America
| | - Ira J. Blader
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
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7
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Ovciarikova J, Shikha S, Lacombe A, Courjol F, McCrone R, Hussain W, Maclean A, Lemgruber L, Martins-Duarte ES, Gissot M, Sheiner L. Two ancient membrane pores mediate mitochondrial-nucleus membrane contact sites. J Cell Biol 2024; 223:e202304075. [PMID: 38456969 PMCID: PMC10923651 DOI: 10.1083/jcb.202304075] [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: 04/22/2023] [Revised: 11/28/2023] [Accepted: 01/29/2024] [Indexed: 03/09/2024] Open
Abstract
Coordination between nucleus and mitochondria is essential for cell survival, and thus numerous communication routes have been established between these two organelles over eukaryotic cell evolution. One route for organelle communication is via membrane contact sites, functional appositions formed by molecular tethers. We describe a novel nuclear-mitochondrial membrane contact site in the protozoan Toxoplasma gondii. We have identified specific contacts occurring at the nuclear pore and demonstrated an interaction between components of the nuclear pore and the mitochondrial protein translocon, highlighting them as molecular tethers. Genetic disruption of the nuclear pore or the TOM translocon components, TgNup503 or TgTom40, respectively, result in contact site reduction, supporting their potential involvement in this tether. TgNup503 depletion further leads to specific mitochondrial morphology and functional defects, supporting a role for nuclear-mitochondrial contacts in mediating their communication. The discovery of a contact formed through interaction between two ancient mitochondrial and nuclear complexes sets the ground for better understanding of mitochondrial-nuclear crosstalk in eukaryotes.
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Affiliation(s)
- Jana Ovciarikova
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Shikha Shikha
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Alice Lacombe
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Flavie Courjol
- CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, University of Lille, Lille, France
| | - Rosalind McCrone
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Wasim Hussain
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Andrew Maclean
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Leandro Lemgruber
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Erica S. Martins-Duarte
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Mathieu Gissot
- CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, University of Lille, Lille, France
| | - Lilach Sheiner
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
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8
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Chelaghma S, Ke H, Barylyuk K, Krueger T, Koreny L, Waller RF. Apical annuli are specialised sites of post-invasion secretion of dense granules in Toxoplasma. eLife 2024; 13:e94201. [PMID: 38270431 PMCID: PMC10857790 DOI: 10.7554/elife.94201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 12/05/2023] [Indexed: 01/26/2024] Open
Abstract
Apicomplexans are ubiquitous intracellular parasites of animals. These parasites use a programmed sequence of secretory events to find, invade, and then re-engineer their host cells to enable parasite growth and proliferation. The secretory organelles micronemes and rhoptries mediate the first steps of invasion. Both secrete their contents through the apical complex which provides an apical opening in the parasite's elaborate inner membrane complex (IMC) - an extensive subpellicular system of flattened membrane cisternae and proteinaceous meshwork that otherwise limits access of the cytoplasm to the plasma membrane for material exchange with the cell exterior. After invasion, a second secretion programme drives host cell remodelling and occurs from dense granules. The site(s) of dense granule exocytosis, however, has been unknown. In Toxoplasma gondii, small subapical annular structures that are embedded in the IMC have been observed, but the role or significance of these apical annuli to plasma membrane function has also been unknown. Here, we determined that integral membrane proteins of the plasma membrane occur specifically at these apical annular sites, that these proteins include SNARE proteins, and that the apical annuli are sites of vesicle fusion and exocytosis. Specifically, we show that dense granules require these structures for the secretion of their cargo proteins. When secretion is perturbed at the apical annuli, parasite growth is strongly impaired. The apical annuli, therefore, represent a second type of IMC-embedded structure to the apical complex that is specialised for protein secretion, and reveal that in Toxoplasma there is a physical separation of the processes of pre- and post-invasion secretion that mediate host-parasite interactions.
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Affiliation(s)
- Sara Chelaghma
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Huiling Ke
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | | | - Thomas Krueger
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Ludek Koreny
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Ross F Waller
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
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9
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Houngue R, Sangaré LO, Alayi TD, Dieng A, Bitard-Feildel T, Boulogne C, Slomianny C, Atindehou CM, Fanou LA, Hathout Y, Callebaut I, Tomavo S. Toxoplasma membrane inositol phospholipid binding protein TgREMIND is essential for secretory organelle function and host infection. Cell Rep 2024; 43:113601. [PMID: 38157297 DOI: 10.1016/j.celrep.2023.113601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 10/25/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024] Open
Abstract
Apicomplexan parasites possess specialized secretory organelles called rhoptries, micronemes, and dense granules that play a vital role in host infection. In this study, we demonstrate that TgREMIND, a protein found in Toxoplasma gondii, is necessary for the biogenesis of rhoptries and dense granules. TgREMIND contains a Fes-CIP4 homology-Bin/Amphiphysin/Rvs (F-BAR) domain, which binds to membrane phospholipids, as well as a novel uncharacterized domain that we have named REMIND (regulator of membrane-interacting domain). Both the F-BAR domain and the REMIND are crucial for TgREMIND functions. When TgREMIND is depleted, there is a significant decrease in the abundance of dense granules and abnormal transparency of rhoptries, leading to a reduction in protein secretion from these organelles. The absence of TgREMIND inhibits host invasion and parasite dissemination, demonstrating that TgREMIND is essential for the proper function of critical secretory organelles required for successful infection by Toxoplasma.
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Affiliation(s)
- Rodrigue Houngue
- Université Paris Saclay, CNRS UMR 9198-CEA, Institute for Integrative Biology of the Cell (I2BC), 91190 Gif sur Yvette, France
| | - Lamba Omar Sangaré
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - Tchilabalo Dilezitoko Alayi
- Department of Pharmaceutical Science, School of Pharmacy and Pharmaceutical Sciences, Binghamton University-SUNY, Johnson City, NY 13790, USA
| | - Aissatou Dieng
- Université Paris Saclay, CNRS UMR 9198-CEA, Institute for Integrative Biology of the Cell (I2BC), 91190 Gif sur Yvette, France
| | - Tristan Bitard-Feildel
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005 Paris, France
| | - Claire Boulogne
- Université Paris Saclay, CNRS UMR 9198-CEA, Institute for Integrative Biology of the Cell (I2BC), 91190 Gif sur Yvette, France; Plateforme Imagerie-Gif, Institut de Biologie Intégrative de la Cellule (I2BC), 91190 Gif sur Yvette, France
| | - Christian Slomianny
- University of Lille, Laboratory of Cell Physiology, INSERM U 1003, 59655 Villeneuve d'Ascq, France
| | - Cynthia Menonve Atindehou
- Université d'Abomey Calavi, Laboratoire de Biochimie et de Biologie Moléculaire, Faculté des Sciences et Technologies, Cotonou, Bénin
| | - Lucie Ayi Fanou
- Université d'Abomey Calavi, Laboratoire de Biochimie et de Biologie Moléculaire, Faculté des Sciences et Technologies, Cotonou, Bénin
| | - Yetrib Hathout
- Department of Pharmaceutical Science, School of Pharmacy and Pharmaceutical Sciences, Binghamton University-SUNY, Johnson City, NY 13790, USA
| | - Isabelle Callebaut
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005 Paris, France
| | - Stanislas Tomavo
- Université Paris Saclay, CNRS UMR 9198-CEA, Institute for Integrative Biology of the Cell (I2BC), 91190 Gif sur Yvette, France.
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10
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Wu M, Ying J, Lin X, Xu C, Zheng X, Zheng Y, Fang Z, Yan B, Zhang N, Mou Y, Tan F. Toxoplasma gondii autophagy-related protein ATG7 maintains apicoplast inheritance by stabilizing and lipidating ATG8. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166891. [PMID: 37739091 DOI: 10.1016/j.bbadis.2023.166891] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/12/2023] [Accepted: 09/19/2023] [Indexed: 09/24/2023]
Abstract
ATG8/LC3-mediated autophagosome formation is a key rate-limiting step in the process of autophagy. The parasitic protist Toxoplasma gondii possesses a single ATG8 homolog (TgATG8), which can localize to either cytosolic autophagosome involved in delivery of autophagic material in bradyzoites, or the outermost membrane of apicoplast, a nonphotosynthetic plastid-like organelle, responsible for maintaining homeostasis in tachyzoites. However, mechanisms that regulate TgATG8 remain insufficiently understood. Here, a TgATG7 conditional knockdown line that we have generated is severely impaired in parasite's growth and exhibits significant defects in the organelle level, strikingly with a fragmentation of the mitochondrial network and a loss of the apicoplast. Specific TgATG7C1133S point mutant complemented line showed that these defects were associated with its E1-type enzyme activity. Both depletion of TgATG7 and mutation of its catalytic cysteine 1133 hindered TgATG8 lipidation and apicoplast localization. Unexpectedly, we also found that depletion of TgATG7 reduced the unlipidated TgATG8 protein level. Subsequently, we determined that TgATG7 was able to interact with TgATG8 directly via its C-terminal domain and multi-monoubiquitination stimulated proteasome-dependent degradation of TgATG8, while TgATG7 could inhibit the degradation through stabilization of TgATG8. Additionally, we identified a putative TgATG8 interacting fragment of TgATG7, 1281-1290aa. Depletion of the fragment impaired the parasite growth and apicoplast inheritance. To our knowledge, our study is the first to elucidate the role of TgATG7 and the ubiquitin-proteasome system in synergistically regulating the non-lipidated pool of TgATG8, suggesting a potential homeostatic mechanism responsible for balancing autophagic activity in T. gondii.
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Affiliation(s)
- Mimi Wu
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jiaqi Ying
- School of the Second Clinical Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xuejing Lin
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Chao Xu
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaozi Zheng
- Teaching Center of Morphological Experiment, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yi Zheng
- Laser Confocal Microscope Lab, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zhouxi Fang
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Baolong Yan
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Nu Zhang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, China.
| | - Yani Mou
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China.
| | - Feng Tan
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China.
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11
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Baptista CG, Hosking S, Gas-Pascual E, Ciampossine L, Abel S, Hakimi MA, Jeffers V, Le Roch K, West CM, Blader IJ. Toxoplasma gondii F-Box Protein L2 Silences Feline-Restricted Genes Necessary for Sexual Commitment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.18.572150. [PMID: 38187549 PMCID: PMC10769283 DOI: 10.1101/2023.12.18.572150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Toxoplasma gondii is a foodborne pathogen that can cause severe and life-threatening infections in fetuses and immunocompromised patients. Felids are its only definitive hosts, and a wide range of animals, including humans, serve as intermediate hosts. When the transmissible bradyzoite stage is orally ingested by felids, they transform into merozoites that expand asexually, ultimately generating millions of gametes for the parasite sexual cycle. However, bradyzoites in intermediate hosts differentiate exclusively to disease-causing tachyzoites, which rapidly disseminate throughout the host. Though tachyzoites are well-studied, the molecular mechanisms governing transitioning between developmental stages are poorly understood. Each parasite stage can be distinguished by a characteristic transcriptional signature, with one signature being repressed during the other stages. Switching between stages requires substantial changes in the proteome, which is achieved in part by ubiquitination. F-box proteins mediate protein poly-ubiquitination by recruiting substrates to SKP1, Cullin-1, F-Box protein E3 ubiquitin ligase (SCF-E3) complexes. We have identified an F-box protein named Toxoplasma gondii F-Box Protein L2 (TgFBXL2), which localizes to distinct nuclear sites. TgFBXL2 is stably engaged in an SCF-E3 complex that is surprisingly also associated with a COP9 signalosome complex that negatively regulates SCF-E3 function. At the cellular level, TgFBXL2-depleted parasites are severely defective in centrosome replication and daughter cell development. Most remarkable, RNA seq data show that TgFBXL2 conditional depletion induces the expression of genes necessary for sexual commitment. We suggest that TgFBXL2 is a latent guardian of sexual stage development in Toxoplasma and poised to remove conflicting proteins in response to an unknown trigger of sexual development.
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Affiliation(s)
- Carlos G. Baptista
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, NY 14203 USA
| | - Sarah Hosking
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, NY 14203 USA
| | - Elisabet Gas-Pascual
- Department of Biochemistry & Molecular Biology, Center for Tropical & Emerging Global Diseases, University of Georgia, Athens, GA 30602 USA
| | - Loic Ciampossine
- Department of Molecular, Cell, and Systems Biology, University of California Riverside, Riverside, CA, 92521USA
| | - Steven Abel
- Department of Molecular, Cell, and Systems Biology, University of California Riverside, Riverside, CA, 92521USA
| | - Mohamed-Ali Hakimi
- Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences (IAB), INSERM U1209, CNRS UMR 5309, Grenoble Alpes University, Grenoble, France
| | - Victoria Jeffers
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824 USA
| | - Karine Le Roch
- Department of Molecular, Cell, and Systems Biology, University of California Riverside, Riverside, CA, 92521USA
| | - Christopher M. West
- Department of Biochemistry & Molecular Biology, Center for Tropical & Emerging Global Diseases, University of Georgia, Athens, GA 30602 USA
| | - Ira J. Blader
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, NY 14203 USA
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12
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Liffner B, Cepeda Diaz AK, Blauwkamp J, Anaguano D, Frolich S, Muralidharan V, Wilson DW, Dvorin JD, Absalon S. Atlas of Plasmodium falciparum intraerythrocytic development using expansion microscopy. eLife 2023; 12:RP88088. [PMID: 38108809 PMCID: PMC10727503 DOI: 10.7554/elife.88088] [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] [Indexed: 12/19/2023] Open
Abstract
Apicomplexan parasites exhibit tremendous diversity in much of their fundamental cell biology, but study of these organisms using light microscopy is often hindered by their small size. Ultrastructural expansion microscopy (U-ExM) is a microscopy preparation method that physically expands the sample by ~4.5×. Here, we apply U-ExM to the human malaria parasite Plasmodium falciparum during the asexual blood stage of its lifecycle to understand how this parasite is organized in three dimensions. Using a combination of dye-conjugated reagents and immunostaining, we have cataloged 13 different P. falciparum structures or organelles across the intraerythrocytic development of this parasite and made multiple observations about fundamental parasite cell biology. We describe that the outer centriolar plaque and its associated proteins anchor the nucleus to the parasite plasma membrane during mitosis. Furthermore, the rhoptries, Golgi, basal complex, and inner membrane complex, which form around this anchoring site while nuclei are still dividing, are concurrently segregated and maintain an association to the outer centriolar plaque until the start of segmentation. We also show that the mitochondrion and apicoplast undergo sequential fission events while maintaining an association with the outer centriolar plaque during cytokinesis. Collectively, this study represents the most detailed ultrastructural analysis of P. falciparum during its intraerythrocytic development to date and sheds light on multiple poorly understood aspects of its organelle biogenesis and fundamental cell biology.
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Affiliation(s)
- Benjamin Liffner
- Department of Pharmacology and Toxicology, Indiana University School of MedicineIndianapolisUnited States
| | - Ana Karla Cepeda Diaz
- Biological and Biomedical Sciences, Harvard Medical SchoolBostonUnited States
- Division of Infectious Diseases, Boston Children’s HospitalBostonUnited States
| | - James Blauwkamp
- Department of Pharmacology and Toxicology, Indiana University School of MedicineIndianapolisUnited States
| | - David Anaguano
- Center for Tropical and Emerging Global Diseases, University of GeorgiaAthensUnited States
- Department of Cellular Biology, Franklin College of Arts and Sciences, University of GeorgiaAthensUnited States
| | - Sonja Frolich
- Research Centre for Infectious Diseases, School of Biological Sciences, University of AdelaideAdelaideAustralia
- Institute for Photonics and Advanced Sensing, University of AdelaideAdelaideAustralia
| | - Vasant Muralidharan
- Center for Tropical and Emerging Global Diseases, University of GeorgiaAthensUnited States
- Department of Cellular Biology, Franklin College of Arts and Sciences, University of GeorgiaAthensUnited States
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, University of AdelaideAdelaideAustralia
- Institute for Photonics and Advanced Sensing, University of AdelaideAdelaideAustralia
- Burnet Institute, 85 Commercial RoadMelbourneAustralia
| | - Jeffrey D Dvorin
- Division of Infectious Diseases, Boston Children’s HospitalBostonUnited States
- Department of Pediatrics, Harvard Medical SchoolBostonUnited States
| | - Sabrina Absalon
- Department of Pharmacology and Toxicology, Indiana University School of MedicineIndianapolisUnited States
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13
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Elati HAA, Goerner AL, Martorelli Di Genova B, Sheiner L, de Koning HP. Pyrimidine salvage in Toxoplasma gondii as a target for new treatment. Front Cell Infect Microbiol 2023; 13:1320160. [PMID: 38162577 PMCID: PMC10755004 DOI: 10.3389/fcimb.2023.1320160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 12/01/2023] [Indexed: 01/03/2024] Open
Abstract
Toxoplasmosis is a common protozoan infection that can have severe outcomes in the immunocompromised and during pregnancy, but treatment options are limited. Recently, nucleotide metabolism has received much attention as a target for new antiprotozoal agents and here we focus on pyrimidine salvage by Toxoplasma gondii as a drug target. Whereas uptake of [3H]-cytidine and particularly [3H]-thymidine was at most marginal, [3H]-uracil and [3H]-uridine were readily taken up. Kinetic analysis of uridine uptake was consistent with a single transporter with a Km of 3.3 ± 0.8 µM, which was inhibited by uracil with high affinity (Ki = 1.15 ± 0.07 µM) but not by thymidine or 5-methyluridine, showing that the 5-Me group is incompatible with uptake by T. gondii. Conversely, [3H]-uracil transport displayed a Km of 2.05 ± 0.40 µM, not significantly different from the uracil Ki on uridine transport, and was inhibited by uridine with a Ki of 2.44 ± 0.59 µM, also not significantly different from the experimental uridine Km. The reciprocal, complete inhibition, displaying Hill slopes of approximately -1, strongly suggest that uridine and uracil share a single transporter with similarly high affinity for both, and we designate it uridine/uracil transporter 1 (TgUUT1). While TgUUT1 excludes 5-methyl substitutions, the smaller 5F substitution was tolerated, as 5F-uracil inhibited uptake of [3H]-uracil with a Ki of 6.80 ± 2.12 µM (P > 0.05 compared to uracil Km). Indeed, we found that 5F-Uridine, 5F-uracil and 5F,2'-deoxyuridine were all potent antimetabolites against T. gondii with EC50 values well below that of the current first line treatment, sulfadiazine. In vivo evaluation also showed that 5F-uracil and 5F,2'-deoxyuridine were similarly effective as sulfadiazine against acute toxoplasmosis. Our preliminary conclusion is that TgUUT1 mediates potential new anti-toxoplasmosis drugs with activity superior to the current treatment.
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Affiliation(s)
- Hamza A. A. Elati
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Department of Pharmacology and Toxicology, Pharmacy College, University of Elmergib, Al Khums, Libya
| | - Amber L. Goerner
- Larner College of Medicine at The University of Vermont, Department of Microbiology and Molecular Genetics, Burlington, VT, United States
| | - Bruno Martorelli Di Genova
- Larner College of Medicine at The University of Vermont, Department of Microbiology and Molecular Genetics, Burlington, VT, United States
| | - Lilach Sheiner
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Harry P. de Koning
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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14
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Silva MF, Douglas K, Sandalli S, Maclean AE, Sheiner L. Functional and biochemical characterization of the Toxoplasma gondii succinate dehydrogenase complex. PLoS Pathog 2023; 19:e1011867. [PMID: 38079448 PMCID: PMC10735183 DOI: 10.1371/journal.ppat.1011867] [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: 07/12/2023] [Revised: 12/21/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023] Open
Abstract
The mitochondrial electron transport chain (mETC) is a series of membrane embedded enzymatic complexes critical for energy conversion and mitochondrial metabolism. In commonly studied eukaryotes, including humans and animals, complex II, also known as succinate dehydrogenase (SDH), is an essential four-subunit enzyme that acts as an entry point to the mETC, by harvesting electrons from the TCA cycle. Apicomplexa are pathogenic parasites with significant impact on human and animal health. The phylum includes Toxoplasma gondii which can cause fatal infections in immunocompromised people. Most apicomplexans, including Toxoplasma, rely on their mETC for survival, yet SDH remains largely understudied. Previous studies pointed to a divergent apicomplexan SDH with nine subunits proposed for the Toxoplasma complex, compared to four in humans. While two of the nine are homologs of the well-studied SDHA and B, the other seven have no homologs in SDHs of other systems. Moreover, SDHC and D, that anchor SDH to the membrane and participate in substrate bindings, have no homologs in Apicomplexa. Here, we validated five of the seven proposed subunits as bona fide SDH components and demonstrated their importance for SDH assembly and activity. We further find that all five subunits are important for parasite growth, and that disruption of SDH impairs mitochondrial respiration and results in spontaneous initiation of differentiation into bradyzoites. Finally, we provide evidence that the five subunits are membrane bound, consistent with their potential role in membrane anchoring, and we demonstrate that a DY motif in one of them, SDH10, is essential for complex formation and function. Our study confirms the divergent composition of Toxoplasma SDH compared to human, and starts exploring the role of the lineage-specific subunits in SDH function, paving the way for future mechanistic studies.
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Affiliation(s)
- Mariana F. Silva
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Kiera Douglas
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Sofia Sandalli
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Andrew E. Maclean
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Lilach Sheiner
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
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15
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Namasivayam S, Sun C, Bah AB, Oberstaller J, Pierre-Louis E, Etheridge RD, Feschotte C, Pritham EJ, Kissinger JC. Massive invasion of organellar DNA drives nuclear genome evolution in Toxoplasma. Proc Natl Acad Sci U S A 2023; 120:e2308569120. [PMID: 37917792 PMCID: PMC10636329 DOI: 10.1073/pnas.2308569120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 09/26/2023] [Indexed: 11/04/2023] Open
Abstract
Toxoplasma gondii is a zoonotic protist pathogen that infects up to one third of the human population. This apicomplexan parasite contains three genome sequences: nuclear (65 Mb); plastid organellar, ptDNA (35 kb); and mitochondrial organellar, mtDNA (5.9 kb of non-repetitive sequence). We find that the nuclear genome contains a significant amount of NUMTs (nuclear integrants of mitochondrial DNA) and NUPTs (nuclear integrants of plastid DNA) that are continuously acquired and represent a significant source of intraspecific genetic variation. NUOT (nuclear DNA of organellar origin) accretion has generated 1.6% of the extant T. gondii ME49 nuclear genome-the highest fraction ever reported in any organism. NUOTs are primarily found in organisms that retain the non-homologous end-joining repair pathway. Significant movement of organellar DNA was experimentally captured via amplicon sequencing of a CRISPR-induced double-strand break in non-homologous end-joining repair competent, but not ku80 mutant, Toxoplasma parasites. Comparisons with Neospora caninum, a species that diverged from Toxoplasma ~28 mya, revealed that the movement and fixation of five NUMTs predates the split of the two genera. This unexpected level of NUMT conservation suggests evolutionary constraint for cellular function. Most NUMT insertions reside within (60%) or nearby genes (23% within 1.5 kb), and reporter assays indicate that some NUMTs have the ability to function as cis-regulatory elements modulating gene expression. Together, these findings portray a role for organellar sequence insertion in dynamically shaping the genomic architecture and likely contributing to adaptation and phenotypic changes in this important human pathogen.
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Affiliation(s)
| | - Cheng Sun
- Department of Biology, University of Texas at Arlington, Arlington, TX76019
| | - Assiatu B. Bah
- Department of Biology, University of Texas at Arlington, Arlington, TX76019
| | | | - Edwin Pierre-Louis
- Department of Cellular Biology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA30602
| | - Ronald Drew Etheridge
- Department of Cellular Biology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA30602
| | - Cedric Feschotte
- Department of Biology, University of Texas at Arlington, Arlington, TX76019
| | - Ellen J. Pritham
- Department of Biology, University of Texas at Arlington, Arlington, TX76019
| | - Jessica C. Kissinger
- Department of Genetics, Institute of Bioinformatics, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA30602
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16
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Usey MM, Huet D. ATP synthase-associated coiled-coil-helix-coiled-coil-helix (CHCH) domain-containing proteins are critical for mitochondrial function in Toxoplasma gondii. mBio 2023; 14:e0176923. [PMID: 37796022 PMCID: PMC10653836 DOI: 10.1128/mbio.01769-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 08/21/2023] [Indexed: 10/06/2023] Open
Abstract
IMPORTANCE Members of the coiled-coil-helix-coiled-coil-helix (CHCH) domain protein family are transported into the mitochondrial intermembrane space, where they play important roles in the biogenesis and function of the organelle. Unexpectedly, the ATP synthase of the apicomplexan Toxoplasma gondii harbors CHCH domain-containing subunits of unknown function. As no other ATP synthase studied to date contains this class of proteins, characterizing their function will be of broad interest to the fields of molecular parasitology and mitochondrial evolution. Here, we demonstrate that that two T. gondii ATP synthase subunits containing CHCH domains are required for parasite survival and for stability and function of the ATP synthase. We also show that knockdown disrupts multiple aspects of the mitochondrial morphology of T. gondii and that mutation of key residues in the CHCH domains caused mis-localization of the proteins. This work provides insight into the unique features of the apicomplexan ATP synthase, which could help to develop therapeutic interventions against this parasite and other apicomplexans, such as the malaria-causing parasite Plasmodium falciparum.
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Affiliation(s)
- Madelaine M. Usey
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Diego Huet
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia, USA
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17
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Liffner B, Cepeda Diaz AK, Blauwkamp J, Anaguano D, Frölich S, Muralidharan V, Wilson DW, Dvorin J, Absalon S. Atlas of Plasmodium falciparum intraerythrocytic development using expansion microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.22.533773. [PMID: 36993606 PMCID: PMC10055389 DOI: 10.1101/2023.03.22.533773] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Apicomplexan parasites exhibit tremendous diversity in much of their fundamental cell biology, but study of these organisms using light microscopy is often hindered by their small size. Ultrastructural expansion microscopy (U-ExM) is a microscopy preparation method that physically expands the sample ~4.5x. Here, we apply U-ExM to the human malaria parasite Plasmodium falciparum during the asexual blood stage of its lifecycle to understand how this parasite is organized in three-dimensions. Using a combination of dye-conjugated reagents and immunostaining, we have catalogued 13 different P. falciparum structures or organelles across the intraerythrocytic development of this parasite and made multiple observations about fundamental parasite cell biology. We describe that the outer centriolar plaque and its associated proteins anchor the nucleus to the parasite plasma membrane during mitosis. Furthermore, the rhoptries, Golgi, basal complex, and inner membrane complex, which form around this anchoring site while nuclei are still dividing, are concurrently segregated and maintain an association to the outer centriolar plaque until the start of segmentation. We also show that the mitochondrion and apicoplast undergo sequential fission events while maintaining an association with the outer centriolar plaque during cytokinesis. Collectively, this study represents the most detailed ultrastructural analysis of P. falciparum during its intraerythrocytic development to date, and sheds light on multiple poorly understood aspects of its organelle biogenesis and fundamental cell biology.
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Affiliation(s)
- Benjamin Liffner
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ana Karla Cepeda Diaz
- Biological and Biomedical Sciences, Harvard Medical School, Boston MA, USA
- Division of Infectious Diseases, Boston Children’s Hospital, Boston MA, USA
| | - James Blauwkamp
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - David Anaguano
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
- Department of Cellular Biology, Franklin College of Arts and Sciences, University of Georgia, Athens, GA, USA
| | - Sonja Frölich
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Vasant Muralidharan
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
- Department of Cellular Biology, Franklin College of Arts and Sciences, University of Georgia, Athens, GA, USA
| | - Danny W. Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
- Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, SA, Australia
- Burnet Institute, 85 Commercial Road, Melbourne, VIC, Australia
| | - Jeffrey Dvorin
- Division of Infectious Diseases, Boston Children’s Hospital, Boston MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Sabrina Absalon
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
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18
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Fleck K, McNutt S, Chu F, Jeffers V. An apicomplexan bromodomain protein, TgBDP1, associates with diverse epigenetic factors to regulate essential transcriptional processes in Toxoplasma gondii. mBio 2023; 14:e0357322. [PMID: 37350586 PMCID: PMC10470533 DOI: 10.1128/mbio.03573-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 04/18/2023] [Indexed: 06/24/2023] Open
Abstract
The protozoan pathogen Toxoplasma gondii relies on tight regulation of gene expression to invade and establish infection in its host. The divergent gene regulatory mechanisms of Toxoplasma and related apicomplexan pathogens rely heavily on regulators of chromatin structure and histone modifications. The important contribution of histone acetylation for Toxoplasma in both acute and chronic infection has been demonstrated, where histone acetylation increases at active gene loci. However, the direct consequences of specific histone acetylation marks and the chromatin pathway that influences transcriptional regulation in response to the modification are unclear. As a reader of lysine acetylation, the bromodomain serves as a mediator between the acetylated histone and transcriptional regulators. Here we show that the bromodomain protein, TgBDP1, which is conserved among Apicomplexa and within the Alveolata superphylum, is essential for Toxoplasma asexual proliferation. Using cleavage under targets and tagmentation, we demonstrate that TgBDP1 is recruited to transcriptional start sites of a large proportion of parasite genes. Transcriptional profiling during TgBDP1 knockdown revealed that loss of TgBDP1 leads to major dysregulation of gene expression, implying multiple roles for TgBDP1 in both gene activation and repression. This is supported by interactome analysis of TgBDP1 demonstrating that TgBDP1 forms a core complex with two other bromodomain proteins and an ApiAP2 factor. This core complex appears to interact with other epigenetic factors such as nucleosome remodeling complexes. We conclude that TgBDP1 interacts with diverse epigenetic regulators to exert opposing influences on gene expression in the Toxoplasma tachyzoite. IMPORTANCE Histone acetylation is critical for proper regulation of gene expression in the single-celled eukaryotic pathogen Toxoplasma gondii. Bromodomain proteins are "readers" of histone acetylation and may link the modified chromatin to transcription factors. Here, we show that the bromodomain protein TgBDP1 is essential for parasite survival and that loss of TgBDP1 results in global dysregulation of gene expression. TgBDP1 is recruited to the promoter region of a large proportion of parasite genes, forms a core complex with two other bromodomain proteins, and interacts with different transcriptional regulatory complexes. We conclude that TgBDP1 is a key factor for sensing specific histone modifications to influence multiple facets of transcriptional regulation in Toxoplasma gondii.
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Affiliation(s)
- Krista Fleck
- Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
| | - Seth McNutt
- Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
| | - Feixia Chu
- Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
| | - Victoria Jeffers
- Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
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19
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Wang QQ, Sun M, Tang T, Lai DH, Liu J, Maity S, He K, Wu XT, Yang J, Li YB, Tang XY, Ding HY, Hide G, Distefano M, Lun ZR, Zhu XQ, Long S. Functional screening reveals Toxoplasma prenylated proteins required for endocytic trafficking and rhoptry protein sorting. mBio 2023; 14:e0130923. [PMID: 37548452 PMCID: PMC10470541 DOI: 10.1128/mbio.01309-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 06/12/2023] [Indexed: 08/08/2023] Open
Abstract
In the apicomplexans, endocytosed cargos (e.g., hemoglobin) are trafficked to a specialized organelle for digestion. This follows a unique endocytotic process at the micropore/cytostome in these parasites. However, the mechanism underlying endocytic trafficking remains elusive, due to the repurposing of classical endocytic proteins for the biogenesis of apical organelles. To resolve this issue, we have exploited the genetic tractability of the model apicomplexan Toxoplasma gondii, which ingests host cytosolic materials (e.g., green fluorescent protein[GFP]). We determined an association between protein prenylation and endocytic trafficking, and using an alkyne-labeled click chemistry approach, the prenylated proteome was characterized. Genome editing, using clustered regularly interspaced short palindromic repaet/CRISPR-associated nuclease 9 (CRISPR/Cas9), was efficiently utilized to generate genetically modified lines for the functional screening of 23 prenylated candidates. This identified four of these proteins that regulate the trafficking of endocytosed GFP vesicles. Among these proteins, Rab1B and YKT6.1 are highly conserved but are non-classical endocytic proteins in eukaryotes. Confocal imaging analysis showed that Rab1B and Ras are substantially localized to both the trans-Golgi network and the endosome-like compartments in the parasite. Conditional knockdown of Rab1B caused a rapid defect in secretory trafficking to the rhoptry bulb, suggesting a trafficking intersection role for the key regulator Rab1B. Further experiments confirmed a critical role for protein prenylation in regulating the stability/activity of these proteins (i.e., Rab1B and YKT6.1) in the parasite. Our findings define the molecular basis of endocytic trafficking and reveal a potential intersection function of Rab1B on membrane trafficking in T. gondii. This might extend to other related protists, including the malarial parasites. IMPORTANCE The protozoan Toxoplasma gondii establishes a permissive niche, in host cells, that allows parasites to acquire large molecules such as proteins. Numerous studies have demonstrated that the parasite repurposes the classical endocytic components for secretory sorting to the apical organelles, leaving the question of endocytic transport to the lysosome-like compartment unclear. Recent studies indicated that endocytic trafficking is likely to associate with protein prenylation in malarial parasites. This information promoted us to examine this association in the model apicomplexan T. gondii and to identify the key components of the prenylated proteome that are involved. By exploiting the genetic tractability of T. gondii and a host GFP acquisition assay, we reveal four non-classical endocytic proteins that regulate the transport of endocytosed cargos (e.g., GFP) in T. gondii. Thus, we extend the principle that protein prenylation regulates endocytic trafficking and elucidate the process of non-classical endocytosis in T. gondii and potentially in other related protists.
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Affiliation(s)
- Qiang-Qiang Wang
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Ming Sun
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Tao Tang
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - De-Hua Lai
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jing Liu
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Sanjay Maity
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Kai He
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xi-Ting Wu
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jiong Yang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yue-Bao Li
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiao-Yan Tang
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hui-Yong Ding
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Geoff Hide
- Biomedical Research and Innovation Centre and Environmental Research and Innovation Centre, School of Science, Engineering and Environment, University of Salford, Salford, United Kingdom
| | - Mark Distefano
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Zhao-Rong Lun
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xing-Quan Zhu
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi Province, China
| | - Shaojun Long
- National Key Laboratory of Veterinary Public Health Security and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
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20
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Leonard RA, Tian Y, Tan F, van Dooren GG, Hayward JA. An essential role for an Fe-S cluster protein in the cytochrome c oxidase complex of Toxoplasma parasites. PLoS Pathog 2023; 19:e1011430. [PMID: 37262100 DOI: 10.1371/journal.ppat.1011430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 05/17/2023] [Indexed: 06/03/2023] Open
Abstract
The mitochondrial electron transport chain (ETC) of apicomplexan parasites differs considerably from the ETC of the animals that these parasites infect, and is the target of numerous anti-parasitic drugs. The cytochrome c oxidase complex (Complex IV) of the apicomplexan Toxoplasma gondii ETC is more than twice the mass and contains subunits not found in human Complex IV, including a 13 kDa protein termed TgApiCox13. TgApiCox13 is homologous to a human iron-sulfur (Fe-S) cluster-containing protein called the mitochondrial inner NEET protein (HsMiNT) which is not a component of Complex IV in humans. Here, we establish that TgApiCox13 is a critical component of Complex IV in T. gondii, required for complex activity and stability. Furthermore, we demonstrate that TgApiCox13, like its human homolog, binds two Fe-S clusters. We show that the Fe-S clusters of TgApiCox13 are critical for ETC function, having an essential role in mediating Complex IV integrity. Our study provides the first functional characterisation of an Fe-S protein in Complex IV.
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Affiliation(s)
- Rachel A Leonard
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Yuan Tian
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Feng Tan
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Giel G van Dooren
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Jenni A Hayward
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
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21
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Namasivayam S, Sun C, Bah AB, Oberstaller J, Pierre-Louis E, Etheridge RD, Feschotte C, Pritham EJ, Kissinger JC. Massive invasion of organellar DNA drives nuclear genome evolution in Toxoplasma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.539837. [PMID: 37293002 PMCID: PMC10245829 DOI: 10.1101/2023.05.22.539837] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Toxoplasma gondii is a zoonotic protist pathogen that infects up to 1/3 of the human population. This apicomplexan parasite contains three genome sequences: nuclear (63 Mb); plastid organellar, ptDNA (35 kb); and mitochondrial organellar, mtDNA (5.9 kb of non-repetitive sequence). We find that the nuclear genome contains a significant amount of NUMTs (nuclear DNA of mitochondrial origin) and NUPTs (nuclear DNA of plastid origin) that are continuously acquired and represent a significant source of intraspecific genetic variation. NUOT (nuclear DNA of organellar origin) accretion has generated 1.6% of the extant T. gondii ME49 nuclear genome; the highest fraction ever reported in any organism. NUOTs are primarily found in organisms that retain the non-homologous end-joining repair pathway. Significant movement of organellar DNA was experimentally captured via amplicon sequencing of a CRISPR-induced double-strand break in non-homologous end-joining repair competent, but not ku80 mutant, Toxoplasma parasites. Comparisons with Neospora caninum, a species that diverged from Toxoplasma ~28 MY ago, revealed that the movement and fixation of 5 NUMTs predates the split of the two genera. This unexpected level of NUMT conservation suggests evolutionary constraint for cellular function. Most NUMT insertions reside within (60%) or nearby genes (23% within 1.5 kb) and reporter assays indicate that some NUMTs have the ability to function as cis-regulatory elements modulating gene expression. Together these findings portray a role for organellar sequence insertion in dynamically shaping the genomic architecture and likely contributing to adaptation and phenotypic changes in this important human pathogen.
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Affiliation(s)
- Sivaranjani Namasivayam
- Department of Genetics, University of Georgia, Athens, GA 30602, USA; Present address: Clinical Microbiome Unit, Laboratory of Host Immunity and Microbiome, NIAID, NIH, Bethesda, MD 20892, USA
| | - Cheng Sun
- Department of Biology, University of Texas at Arlington, Arlington, TX 76019, USA; Present address: College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Assiatu B Bah
- Department of Biology, University of Texas at Arlington, Arlington, TX 76019
| | - Jenna Oberstaller
- Department of Genetics, University of Georgia, Athens, GA 30602, USA; Present address: Department of Global Health, University of South Florida, Tampa, FL 33620, USA
| | - Edwin Pierre-Louis
- Department of Cellular Biology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Ronald Drew Etheridge
- Department of Cellular Biology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Cedric Feschotte
- Department of Biology, University of Texas at Arlington, Arlington, TX 76019; Present address: Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703, USA
| | - Ellen J. Pritham
- Department of Biology, University of Texas at Arlington, Arlington, TX 76019
| | - Jessica C. Kissinger
- Department of Genetics, Institute of Bioinformatics, and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
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22
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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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23
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Howieson VM, Zeng J, Kloehn J, Spry C, Marchetti C, Lunghi M, Varesio E, Soper A, Coyne AG, Abell C, van Dooren GG, Saliba KJ. Pantothenate biosynthesis in Toxoplasma gondii tachyzoites is not a drug target. INTERNATIONAL JOURNAL FOR PARASITOLOGY: DRUGS AND DRUG RESISTANCE 2023; 22:1-8. [PMID: 37004488 PMCID: PMC10102396 DOI: 10.1016/j.ijpddr.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 03/08/2023] [Accepted: 03/12/2023] [Indexed: 03/17/2023]
Abstract
Toxoplasma gondii is a pervasive apicomplexan parasite that can cause severe disease and death in immunocompromised individuals and the developing foetus. The treatment of toxoplasmosis often leads to serious side effects and novel drugs and drug targets are therefore actively sought. In 2014, Mageed and colleagues suggested that the T. gondii pantothenate synthetase, the enzyme responsible for the synthesis of the vitamin B5 (pantothenate), the precursor of the important cofactor, coenzyme A, is a good drug target. Their conclusion was based on the ability of potent inhibitors of the M. tuberculosis pantothenate synthetase to inhibit the proliferation of T. gondii tachyzoites. They also reported that the inhibitory effect of the compounds could be antagonised by supplementing the medium with pantothenate, supporting their conclusion that the compounds were acting on the intended target. Contrary to these observations, we find that compound SW314, one of the compounds used in the Mageed et al. study and previously shown to be active against M. tuberculosis pantothenate synthetase in vitro, is inactive against the T. gondii pantothenate synthetase and does not inhibit tachyzoite proliferation, despite gaining access into the parasite in situ. Furthermore, we validate the recent observation that the pantothenate synthetase gene in T. gondii can be disrupted without detrimental effect to the survival of the tachyzoite-stage parasite in the presence or absence of extracellular pantothenate. We conclude that the T. gondii pantothenate synthetase is not essential during the tachyzoite stage of the parasite and it is therefore not a target for drug discovery against T. gondii tachyzoites.
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24
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Walczak M, Meister TR, Nguyen HM, Zhu Y, Besteiro S, Yeh E. Structure-Function Relationship for a Divergent Atg8 Protein Required for a Nonautophagic Function in Apicomplexan Parasites. mBio 2023; 14:e0364221. [PMID: 36625582 PMCID: PMC9973341 DOI: 10.1128/mbio.03642-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Atg8 family proteins are highly conserved eukaryotic proteins with diverse autophagy and nonautophagic functions in eukaryotes. While the structural features required for conserved autophagy functions of Atg8 are well established, little is known about the molecular changes that facilitated acquisition of divergent, nonautophagic functions of Atg8. The malaria parasite Plasmodium falciparum offers a unique opportunity to study nonautophagic functions of Atg8 family proteins because it encodes a single Atg8 homolog whose only essential function is in the inheritance of an unusual secondary plastid called the apicoplast. Here, we used functional complementation to investigate the structure-function relationship for this divergent Atg8 protein. We showed that the LC3-interacting region (LIR) docking site (LDS), the major interaction interface of the Atg8 protein family, is required for P. falciparum Atg8 (PfAtg8) apicoplast localization and function, likely via Atg8 lipidation. On the other hand, another region previously implicated in canonical Atg8 interactions, the N-terminal helix, is not required for apicoplast-specific PfAtg8 function. Finally, our investigations at the cellular level demonstrate that the unique apicomplexan-specific loop, previously implicated in interaction with membrane conjugation machinery in recombinant protein-based in vitro assays, is not required for membrane conjugation nor for the apicoplast-specific effector function of Atg8 in both P. falciparum and related Apicomplexa member Toxoplasma gondii. These results suggest that the effector function of apicomplexan Atg8 is mediated by structural features distinct from those previously identified for macroautophagy and selective autophagy functions. IMPORTANCE The most extensively studied role of Atg8 proteins is in autophagy. However, it is clear that they have other nonautophagic functions critical to cell function and disease pathogenesis that are so far understudied compared to their canonical role in autophagy. Mammalian cells contain multiple Atg8 paralogs that have diverse, specialized functions. Gaining molecular insight into their nonautophagic functions is difficult because of redundancy between the homologs and their role in both autophagy and nonautophagic pathways. Malaria parasites such as Plasmodium falciparum are a unique system to study a novel, nonautophagic function of Atg8 separate from its role in autophagy: they have only one Atg8 protein whose only essential function is in the inheritance of the apicoplast, a unique secondary plastid organelle. Insights into the molecular basis of PfAtg8's function in apicoplast biogenesis will have important implications for the evolution of diverse nonautophagic functions of the Atg8 protein family.
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Affiliation(s)
- Marta Walczak
- Department of Pathology, Stanford School of Medicine, Stanford, California, USA
| | - Thomas R. Meister
- Department of Molecular and Cellular Physiology, Stanford School of Medicine, Stanford, California, USA
| | - Hoa Mai Nguyen
- LPHI UMR5235, University of Montpellier, CNRS, Montpellier, France
| | - Yili Zhu
- Department of Pathology, Stanford School of Medicine, Stanford, California, USA
| | | | - Ellen Yeh
- Department of Pathology, Stanford School of Medicine, Stanford, California, USA
- Department of Microbiology & Immunology, Stanford School of Medicine, Stanford, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
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25
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Invasion of Toxoplasma gondii bradyzoites: Molecular dissection of the moving junction proteins and effective vaccination targets. Proc Natl Acad Sci U S A 2023; 120:e2219533120. [PMID: 36693095 PMCID: PMC9945962 DOI: 10.1073/pnas.2219533120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Toxoplasmosis is a neglected parasitic disease necessitating public health control. Host cell invasion by Toxoplasma occurs at different stages of the parasite's life cycle and is crucial for survival and establishment of infection. In tachyzoites, which are responsible for acute toxoplasmosis, invasion involves the formation of a molecular bridge between the parasite and host cell membranes, referred to as the moving junction (MJ). The MJ is shaped by the assembly of AMA1 and RON2, as part of a complex involving additional RONs. While this essential process is well characterized in tachyzoites, the invasion process remains unexplored in bradyzoites, which form cysts and are responsible for chronic toxoplasmosis and contribute to the dissemination of the parasite between hosts. Here, we show that bradyzoites invade host cells in an MJ-dependent fashion but differ in protein composition from the tachyzoite MJ, relying instead on the paralogs AMA2 and AMA4. Functional characterization of AMA4 reveals its key role for cysts burden during the onset of chronic infection, while being dispensable for the acute phase. Immunizations with AMA1 and AMA4, alone or in complex with their rhoptry neck respective partners RON2 and RON2L1, showed that the AMA1-RON2 pair induces strong protection against acute and chronic infection, while the AMA4-RON2L1 complex targets more selectively the chronic form. Our study provides important insights into the molecular players of bradyzoite invasion and indicates that invasion of cyst-forming bradyzoites contributes to cyst burden. Furthermore, we validate AMA-RON complexes as potential vaccine candidates to protect against toxoplasmosis.
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26
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Sparvoli D, Delabre J, Penarete‐Vargas DM, Kumar Mageswaran S, Tsypin LM, Heckendorn J, Theveny L, Maynadier M, Mendonça Cova M, Berry‐Sterkers L, Guérin A, Dubremetz J, Urbach S, Striepen B, Turkewitz AP, Chang Y, Lebrun M. An apical membrane complex for triggering rhoptry exocytosis and invasion in Toxoplasma. EMBO J 2022; 41:e111158. [PMID: 36245278 PMCID: PMC9670195 DOI: 10.15252/embj.2022111158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 09/13/2022] [Accepted: 09/19/2022] [Indexed: 01/13/2023] Open
Abstract
Apicomplexan parasites possess secretory organelles called rhoptries that undergo regulated exocytosis upon contact with the host. This process is essential for the parasitic lifestyle of these pathogens and relies on an exocytic machinery sharing structural features and molecular components with free-living ciliates. However, how the parasites coordinate exocytosis with host interaction is unknown. Here, we performed a Tetrahymena-based transcriptomic screen to uncover novel exocytic factors in Ciliata and conserved in Apicomplexa. We identified membrane-bound proteins, named CRMPs, forming part of a large complex essential for rhoptry secretion and invasion in Toxoplasma. Using cutting-edge imaging tools, including expansion microscopy and cryo-electron tomography, we show that, unlike previously described rhoptry exocytic factors, TgCRMPs are not required for the assembly of the rhoptry secretion machinery and only transiently associate with the exocytic site-prior to the invasion. CRMPs and their partners contain putative host cell-binding domains, and CRMPa shares similarities with GPCR proteins. Collectively our data imply that the CRMP complex acts as a host-molecular sensor to ensure that rhoptry exocytosis occurs when the parasite contacts the host cell.
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Affiliation(s)
- Daniela Sparvoli
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Jason Delabre
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | | | - Shrawan Kumar Mageswaran
- Department of Biochemistry and Biophysics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Lev M Tsypin
- Department of Molecular Genetics and Cell BiologyUniversity of ChicagoChicagoILUSA
- Present address:
Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCAUSA
| | - Justine Heckendorn
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Liam Theveny
- Department of Biochemistry and Biophysics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Marjorie Maynadier
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Marta Mendonça Cova
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Laurence Berry‐Sterkers
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Amandine Guérin
- Department of Pathobiology, School of Veterinary MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Jean‐François Dubremetz
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
| | - Serge Urbach
- IGFUniversité de Montpellier, CNRS, INSERMMontpellierFrance
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Aaron P Turkewitz
- Department of Molecular Genetics and Cell BiologyUniversity of ChicagoChicagoILUSA
| | - Yi‐Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Maryse Lebrun
- Laboratory of Pathogen Host InteractionsUMR 5235 CNRS, Université de MontpellierMontpellierFrance
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27
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Sleda MA, Li ZH, Behera R, Baierna B, Li C, Jumpathong J, Malwal SR, Kawamukai M, Oldfield E, Moreno SNJ. The Heptaprenyl Diphosphate Synthase (Coq1) Is the Target of a Lipophilic Bisphosphonate That Protects Mice against Toxoplasma gondii Infection. mBio 2022; 13:e0196622. [PMID: 36129297 PMCID: PMC9600589 DOI: 10.1128/mbio.01966-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 08/15/2022] [Indexed: 11/20/2022] Open
Abstract
Prenyldiphosphate synthases catalyze the reaction of allylic diphosphates with one or more isopentenyl diphosphate molecules to form compounds such as farnesyl diphosphate, used in, e.g., sterol biosynthesis and protein prenylation, as well as longer "polyprenyl" diphosphates, used in ubiquinone and menaquinone biosynthesis. Quinones play an essential role in electron transport and are associated with the inner mitochondrial membrane due to the presence of the polyprenyl group. In this work, we investigated the synthesis of the polyprenyl diphosphate that alkylates the ubiquinone ring precursor in Toxoplasma gondii, an opportunistic pathogen that causes serious disease in immunocompromised patients and the unborn fetus. The enzyme that catalyzes this early step of the ubiquinone synthesis is Coq1 (TgCoq1), and we show that it produces the C35 species heptaprenyl diphosphate. TgCoq1 localizes to the mitochondrion and is essential for in vitro T. gondii growth. We demonstrate that the growth defect of a T. gondii TgCoq1 mutant is rescued by complementation with a homologous TgCoq1 gene or with a (C45) solanesyl diphosphate synthase from Trypanosoma cruzi (TcSPPS). We find that a lipophilic bisphosphonate (BPH-1218) inhibits T. gondii growth at low-nanomolar concentrations, while overexpression of the TgCoq1 enzyme dramatically reduced growth inhibition by the bisphosphonate. Both the severe growth defect of the mutant and the inhibition by BPH-1218 were rescued by supplementation with a long-chain (C30) ubiquinone (UQ6). Importantly, BPH-1218 also protected mice against a lethal T. gondii infection. TgCoq1 thus represents a potential drug target that could be exploited for improved chemotherapy of toxoplasmosis. IMPORTANCE Millions of people are infected with Toxoplasma gondii, and the available treatment for toxoplasmosis is not ideal. Most of the drugs currently used are only effective for the acute infection, and treatment can trigger serious side effects requiring changes in the therapeutic approach. There is, therefore, a compelling need for safe and effective treatments for toxoplasmosis. In this work, we characterize an enzyme of the mitochondrion of T. gondii that can be inhibited by an isoprenoid pathway inhibitor. We present evidence that demonstrates that inhibition of the enzyme is linked to parasite death. In addition, the inhibitor can protect mice against a lethal dose of T. gondii. Our results thus reveal a promising chemotherapeutic target for the development of new medicines for toxoplasmosis.
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Affiliation(s)
- Melissa A. Sleda
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
| | - Zhu-Hong Li
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Ranjan Behera
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Baihetiya Baierna
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
| | - Catherine Li
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Jomkwan Jumpathong
- Department of Life Sciences, Faculty of Life and Environmental Sciences, Shimane University, Matsue, Japan
| | - Satish R. Malwal
- Department of Chemistry, University of Illinois at Urbana Champaign, Urbana, Illinois, USA
| | - Makoto Kawamukai
- Department of Life Sciences, Faculty of Life and Environmental Sciences, Shimane University, Matsue, Japan
| | - Eric Oldfield
- Department of Chemistry, University of Illinois at Urbana Champaign, Urbana, Illinois, USA
| | - Silvia N. J. Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
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Dos Santos Pacheco N, Brusini L, Haase R, Tosetti N, Maco B, Brochet M, Vadas O, Soldati-Favre D. Conoid extrusion regulates glideosome assembly to control motility and invasion in Apicomplexa. Nat Microbiol 2022; 7:1777-1790. [DOI: 10.1038/s41564-022-01212-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 07/22/2022] [Indexed: 12/18/2022]
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A distinct class of GTP-binding proteins mediates chloroplast protein import in Rhodophyta. Proc Natl Acad Sci U S A 2022; 119:e2208277119. [PMID: 35969755 PMCID: PMC9407449 DOI: 10.1073/pnas.2208277119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Chloroplast protein import is mediated by translocons named TOC and TIC on the outer and inner envelope membranes, respectively. Translocon constituents are conserved among green lineages, including plants and green algae. However, it remains unclear whether Rhodophyta (red algae) share common chloroplast protein import mechanisms with the green lineages. We show that in the rhodophyte Cyanidioschyzon merolae, plastome-encoded Tic20pt localized to the chloroplast envelope and was transiently associated with preproteins during import, suggesting its conserved function as a TIC constituent. Besides plastome-encoded FtsHpt and several chaperones, a class of GTP (guanosine 5′-triphosphate)-binding proteins distinct from the Toc34/159 GTPase family associated transiently with preproteins. This class of proteins resides mainly in the cytosol and shows sequence similarities with Sey1/RHD3, required for endoplasmic reticulum membrane fusion, and with the periplastid-localized import factor PPP1, previously identified in the Apicomplexa and diatoms. These GTP-binding proteins, named plastid targeting factor for protein import 1 (PTF1) to PTF3, may act as plastid targeting factors in Rhodophyta.
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30
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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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31
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Disrupting the plastidic iron-sulfur cluster biogenesis pathway in Toxoplasma gondii has pleiotropic effects irreversibly impacting parasite viability. J Biol Chem 2022; 298:102243. [PMID: 35810787 PMCID: PMC9386495 DOI: 10.1016/j.jbc.2022.102243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 11/27/2022] Open
Abstract
Like many other apicomplexan parasites, Toxoplasma gondii contains a plastid harboring key metabolic pathways, including the sulfur utilization factor (SUF) pathway that is involved in the biosynthesis of iron-sulfur clusters. These cofactors are crucial for a variety of proteins involved in important metabolic reactions, potentially including plastidic pathways for the synthesis of isoprenoid and fatty acids. It was shown previously that impairing the NFS2 cysteine desulfurase, involved in the first step of the SUF pathway, leads to an irreversible killing of intracellular parasites. However, the metabolic impact of disrupting the pathway remained unexplored. Here, we generated another mutant of this pathway, deficient in the SUFC ATPase, and investigated in details the phenotypic consequences of TgNFS2 and TgSUFC depletion on the parasites. Our analysis confirms that Toxoplasma SUF mutants are severely and irreversibly impacted in division and membrane homeostasis, and suggests a defect in apicoplast-generated fatty acids. However, we show that increased scavenging from the host or supplementation with exogenous fatty acids do not fully restore parasite growth, suggesting that this is not the primary cause for the demise of the parasites and that other important cellular functions were affected. For instance, we also show that the SUF pathway is key for generating the isoprenoid-derived precursors necessary for the proper targeting of GPI-anchored proteins and for parasite motility. Thus, we conclude plastid-generated iron-sulfur clusters support the functions of proteins involved in several vital downstream cellular pathways, which implies the SUF machinery may be explored for new potential anti-Toxoplasma targets.
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32
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Possenti A, Di Cristina M, Nicastro C, Lunghi M, Messina V, Piro F, Tramontana L, Cherchi S, Falchi M, Bertuccini L, Spano F. Functional Characterization of the Thrombospondin-Related Paralogous Proteins Rhoptry Discharge Factors 1 and 2 Unveils Phenotypic Plasticity in Toxoplasma gondii Rhoptry Exocytosis. Front Microbiol 2022; 13:899243. [PMID: 35756016 PMCID: PMC9218915 DOI: 10.3389/fmicb.2022.899243] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
To gain access to the intracellular cytoplasmic niche essential for their growth and replication, apicomplexan parasites such as Toxoplasma gondii rely on the timely secretion of two types of apical organelles named micronemes and rhoptries. Rhoptry proteins are key to host cell invasion and remodeling, however, the molecular mechanisms underlying the tight control of rhoptry discharge are poorly understood. Here, we report the identification and functional characterization of two novel T. gondii thrombospondin-related proteins implicated in rhoptry exocytosis. The two proteins, already annotated as MIC15 and MIC14, were renamed rhoptry discharge factor 1 (RDF1) and rhoptry discharge factor 2 (RDF2) and found to be exclusive of the Coccidia class of apicomplexan parasites. Furthermore, they were shown to have a paralogous relationship and share a C-terminal transmembrane domain followed by a short cytoplasmic tail. Immunofluorescence analysis of T. gondii tachyzoites revealed that RDF1 presents a diffuse punctate localization not reminiscent of any know subcellular compartment, whereas RDF2 was not detected. Using a conditional knockdown approach, we demonstrated that RDF1 loss caused a marked growth defect. The lack of the protein did not affect parasite gliding motility, host cell attachment, replication and egress, whereas invasion was dramatically reduced. Notably, while RDF1 depletion did not result in altered microneme exocytosis, rhoptry discharge was found to be heavily impaired. Interestingly, rhoptry secretion was reversed by spontaneous upregulation of the RDF2 gene in knockdown parasites grown under constant RDF1 repression. Collectively, our results identify RDF1 and RDF2 as additional key players in the pathway controlling rhoptry discharge. Furthermore, this study unveils a new example of compensatory mechanism contributing to phenotypic plasticity in T. gondii.
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Affiliation(s)
- Alessia Possenti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Manlio Di Cristina
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Chiara Nicastro
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Matteo Lunghi
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Valeria Messina
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Federica Piro
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Lorenzo Tramontana
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Simona Cherchi
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Mario Falchi
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy
| | | | - Furio Spano
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
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33
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Gubbels MJ, Ferguson DJP, Saha S, Romano JD, Chavan S, Primo VA, Michaud C, Coppens I, Engelberg K. Toxoplasma gondii's Basal Complex: The Other Apicomplexan Business End Is Multifunctional. Front Cell Infect Microbiol 2022; 12:882166. [PMID: 35573773 PMCID: PMC9103881 DOI: 10.3389/fcimb.2022.882166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/30/2022] [Indexed: 01/08/2023] Open
Abstract
The Apicomplexa are famously named for their apical complex, a constellation of organelles at their apical end dedicated to invasion of their host cells. In contrast, at the other end of the cell, the basal complex (BC) has been overshadowed since it is much less prominent and specific functions were not immediately obvious. However, in the past decade a staggering array of functions have been associated with the BC and strides have been made in understanding its structure. Here, these collective insights are supplemented with new data to provide an overview of the understanding of the BC in Toxoplasma gondii. The emerging picture is that the BC is a dynamic and multifunctional complex, with a series of (putative) functions. The BC has multiple roles in cell division: it is the site where building blocks are added to the cytoskeleton scaffold; it exerts a two-step stretch and constriction mechanism as contractile ring; and it is key in organelle division. Furthermore, the BC has numerous putative roles in 'import', such as the recycling of mother cell remnants, the acquisition of host-derived vesicles, possibly the uptake of lipids derived from the extracellular medium, and the endocytosis of micronemal proteins. The latter process ties the BC to motility, whereas an additional role in motility is conferred by Myosin C. Furthermore, the BC acts on the assembly and/or function of the intravacuolar network, which may directly or indirectly contribute to the establishment of chronic tissue cysts. Here we provide experimental support for molecules acting in several of these processes and identify several new BC proteins critical to maintaining the cytoplasmic bridge between divided parasites. However, the dispensable nature of many BC components leaves many questions unanswered regarding its function. In conclusion, the BC in T. gondii is a dynamic and multifunctional structure at the posterior end of the parasite.
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Affiliation(s)
- Marc-Jan Gubbels
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - 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
| | - Sudeshna Saha
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Julia D. Romano
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Suyog Chavan
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Vincent A. Primo
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Cynthia Michaud
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Klemens Engelberg
- Department of Biology, Boston College, Chestnut Hill, MA, United States
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34
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Identification and Validation of Toxoplasma gondii Mitoribosomal Large Subunit Components. Microorganisms 2022; 10:microorganisms10050863. [PMID: 35630308 PMCID: PMC9145746 DOI: 10.3390/microorganisms10050863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 12/10/2022] Open
Abstract
Mitochondrial ribosomes are fundamental to mitochondrial function, and thus survival, of nearly all eukaryotes. Despite their common ancestry, mitoribosomes have evolved divergent features in different eukaryotic lineages. In apicomplexans, the mitochondrial rRNA is extremely fragmented raising questions about its evolution, protein composition and structure. Apicomplexan mitochondrial translation and the mitoribosomes are essential in all parasites and life stages studied, highlighting mitoribosomes as a promising target for drugs. Still, the apicomplexan mitoribosome is understudied, with one of the obstacles being that its composition is unknown. Here, to facilitate the study of apicomplexan mitoribosomes, we identified and validated components of the mitoribosomal large subunit in the model apicomplexan Toxoplasma gondii.
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35
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Toxoplasma TgAtg8-TgAtg3 Interaction Primarily Contributes to Apicoplast Inheritance and Parasite Growth in Tachyzoite. Microbiol Spectr 2022; 10:e0149521. [PMID: 35196797 PMCID: PMC8865545 DOI: 10.1128/spectrum.01495-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The apicoplast, which harbors key pathways involved in biosynthesis of vital metabolites, is a unique and essential nonphotosynthetic plastid organelle in apicomplexan parasites. Intriguingly, autophagy-related protein 8 (Atg8), a highly conserved eukaryotic protein, can localize to the outermost membrane of the apicoplast and modulate its inheritance in both Toxoplasma and Plasmodium parasites. The Atg8-Atg3 interaction plays a key role in Atg8 lipidation and localization, and our previously work in Toxoplasma has suggested that the core Atg8-family interacting motif (AIM) in TgAtg3, 239FADI242, and the R27 residue of TgAtg8 contribute to TgAtg8-TgAtg3 interaction in vitro. However, little is known about the function of this interaction or its importance in tachyzoite growth in Toxoplasma gondii. Here, we generated two complemented cell lines, TgAtg3F239A/I242A and TgAtg8R27E, based on the TgAtg3 and TgAtg8 conditional knockdown cell lines, respectively. We found that both mutant complemented cell lines were severely affected in terms of tachyzoite growth and displayed delayed death upon conditional knockdown of endogenous TgAtg3 or TgAtg8. Intriguingly, both complemented lines appeared to be defective in TgAtg8 lipidation and apicoplast inheritance. Moreover, we showed that the interaction of TgAtg8 and TgAtg3 is critical for TgAtg8 apicoplast localization. In addition, we found that the TgAtg3F239A/I242A complemented line exhibits an integral mitochondrial network upon ablation of endogenous TgAtg3, which is distinct from TgAtg3-depleted parasites with a fragmented mitochondrial network. Taken together, this work solidifies the contribution of the TgAtg8-TgAtg3 interaction to apicoplast inheritance and the growth of T. gondii tachyzoites. IMPORTANCEToxoplasma gondiiis a widespread intracellular parasite infecting a variety of warm-blooded animals, including humans. Current frontline treatment of toxoplasmosis suffers many drawbacks, including toxicity, drug resistance, and failure to eradicate tissue cysts, underscoring the need to identify novel drug targets for suppression or treatment of toxoplasmosis. TgAtg8 is thought to serve multiple functions in lipidation and is considered essential to the growth and development of both tachyzoites and bradyzoites. Here, we show that Toxoplasma gondii has adapted a conserved Atg8-Atg3 interaction, required for canonical autophagy in other eukaryotes, to function specifically in apicoplast inheritance. Our finding not only highlights the importance of TgAtg8-TgAtg3 interaction in tachyzoite growth but also suggests that this interaction is a promising drug target for the therapy of toxoplasmosis.
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36
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Pamukcu S, Cerutti A, Bordat Y, Hem S, Rofidal V, Besteiro S. Differential contribution of two organelles of endosymbiotic origin to iron-sulfur cluster synthesis and overall fitness in Toxoplasma. PLoS Pathog 2021; 17:e1010096. [PMID: 34793583 PMCID: PMC8639094 DOI: 10.1371/journal.ppat.1010096] [Citation(s) in RCA: 9] [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: 09/01/2021] [Revised: 12/02/2021] [Accepted: 11/05/2021] [Indexed: 11/21/2022] Open
Abstract
Iron-sulfur (Fe-S) clusters are one of the most ancient and ubiquitous prosthetic groups, and they are required by a variety of proteins involved in important metabolic processes. Apicomplexan parasites have inherited different plastidic and mitochondrial Fe-S clusters biosynthesis pathways through endosymbiosis. We have investigated the relative contributions of these pathways to the fitness of Toxoplasma gondii, an apicomplexan parasite causing disease in humans, by generating specific mutants. Phenotypic analysis and quantitative proteomics allowed us to highlight notable differences in these mutants. Both Fe-S cluster synthesis pathways are necessary for optimal parasite growth in vitro, but their disruption leads to markedly different fates: impairment of the plastidic pathway leads to a loss of the organelle and to parasite death, while disruption of the mitochondrial pathway trigger differentiation into a stress resistance stage. This highlights that otherwise similar biochemical pathways hosted by different sub-cellular compartments can have very different contributions to the biology of the parasites, which is something to consider when exploring novel strategies for therapeutic intervention.
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Affiliation(s)
| | - Aude Cerutti
- LPHI, Univ Montpellier, CNRS, Montpellier, France
| | - Yann Bordat
- LPHI, Univ Montpellier, CNRS, Montpellier, France
| | - Sonia Hem
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Valérie Rofidal
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
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37
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Mallo N, Ovciarikova J, Martins-Duarte ES, Baehr SC, Biddau M, Wilde ML, Uboldi AD, Lemgruber L, Tonkin CJ, Wideman JG, Harding CR, Sheiner L. Depletion of a Toxoplasma porin leads to defects in mitochondrial morphology and contacts with the endoplasmic reticulum. J Cell Sci 2021; 134:272536. [PMID: 34523684 PMCID: PMC8572010 DOI: 10.1242/jcs.255299] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 09/06/2021] [Indexed: 01/21/2023] Open
Abstract
The voltage-dependent anion channel (VDAC) is a ubiquitous channel in the outer membrane of the mitochondrion with multiple roles in protein, metabolite and small molecule transport. In mammalian cells, VDAC protein, as part of a larger complex including the inositol triphosphate receptor, has been shown to have a role in mediating contacts between the mitochondria and endoplasmic reticulum (ER). We identify VDAC of the pathogenic apicomplexan Toxoplasma gondii and demonstrate its importance for parasite growth. We show that VDAC is involved in protein import and metabolite transfer to mitochondria. Further, depletion of VDAC resulted in significant morphological changes in the mitochondrion and ER, suggesting a role in mediating contacts between these organelles in T. gondii. This article has an associated First Person interview with the first author of the paper. Summary: Depletion of the Toxoplasma voltage-dependent anion channel highlights the importance of endoplasmic reticulum–mitochondria membrane contact sites in maintaining organelle morphology.
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Affiliation(s)
- Natalia Mallo
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8TA, UK
| | - Jana Ovciarikova
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8TA, UK
| | - Erica S Martins-Duarte
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 486 31270-901, Brazil
| | - Stephan C Baehr
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Marco Biddau
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8TA, UK
| | - Mary-Louise Wilde
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC 3086, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Alessandro D Uboldi
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC 3086, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Leandro Lemgruber
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8TA, UK.,Glasgow Imaging Facility, University of Glasgow, Glasgow G12 8TA, UK
| | - Christopher J Tonkin
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC 3086, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Jeremy G Wideman
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Clare R Harding
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8TA, UK
| | - Lilach Sheiner
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8TA, UK
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38
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Li ZH, King TP, Ayong L, Asady B, Cai X, Rahman T, Vella SA, Coppens I, Patel S, Moreno SNJ. A plastid two-pore channel essential for inter-organelle communication and growth of Toxoplasma gondii. Nat Commun 2021; 12:5802. [PMID: 34608145 PMCID: PMC8490419 DOI: 10.1038/s41467-021-25987-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/06/2021] [Indexed: 01/04/2023] Open
Abstract
Two-pore channels (TPCs) are a ubiquitous family of cation channels that localize to acidic organelles in animals and plants to regulate numerous Ca2+-dependent events. Little is known about TPCs in unicellular organisms despite their ancient origins. Here, we characterize a TPC from Toxoplasma gondii, the causative agent of toxoplasmosis. TgTPC is a member of a novel clad of TPCs in Apicomplexa, distinct from previously identified TPCs and only present in coccidians. We show that TgTPC localizes not to acidic organelles but to the apicoplast, a non-photosynthetic plastid found in most apicomplexan parasites. Conditional silencing of TgTPC resulted in progressive loss of apicoplast integrity, severely affecting growth and the lytic cycle. Isolation of TPC null mutants revealed a selective role for TPCs in replication independent of apicoplast loss that required conserved residues within the pore-lining region. Using a genetically-encoded Ca2+ indicator targeted to the apicoplast, we show that Ca2+ signals deriving from the ER but not from the extracellular space are selectively transmitted to the lumen. Deletion of the TgTPC gene caused reduced apicoplast Ca2+ uptake and membrane contact site formation between the apicoplast and the ER. Fundamental roles for TPCs in maintaining organelle integrity, inter-organelle communication and growth emerge.
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Affiliation(s)
- Zhu-Hong Li
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Thayer P King
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Lawrence Ayong
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Beejan Asady
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Heath, Baltimore, MD, 21205, USA
| | - Xinjiang Cai
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, USA
| | - Stephen A Vella
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Heath, Baltimore, MD, 21205, USA
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Silvia N J Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA. .,Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA.
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39
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Briquet S, Gissot M, Silvie O. A toolbox for conditional control of gene expression in apicomplexan parasites. Mol Microbiol 2021; 117:618-631. [PMID: 34564906 PMCID: PMC9293482 DOI: 10.1111/mmi.14821] [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] [Received: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 01/29/2023]
Abstract
Apicomplexan parasites encompass diverse pathogens for humans and animals, including the causative agents of malaria and toxoplasmosis, Plasmodium spp. and Toxoplasma gondii. Genetic manipulation of these parasites has become central to explore parasite biology, unravel gene function and identify new targets for therapeutic strategies. Tremendous progress has been achieved over the past years with the advent of next generation sequencing and powerful genome editing methods. In particular, various methods for conditional gene expression have been developed in both Plasmodium and Toxoplasma to knockout or knockdown essential genes, or for inducible expression of master developmental regulators or mutant versions of proteins. Conditional gene expression can be achieved at three distinct levels. At the DNA level, inducible site‐specific recombinases allow conditional genome editing. At the RNA level, regulation can be achieved during transcription, using stage‐specific or regulatable promoters, or post‐transcriptionally through alteration of mRNA stability or translation. At the protein level, several systems have been developed for inducible degradation or displacement of a protein of interest. In this review, we provide an overview of current systems for conditional control of gene expression in Plasmodium and Toxoplasma parasites, highlighting the advantages and limitations of each approach.
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Affiliation(s)
- Sylvie Briquet
- INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, Sorbonne Université, Paris, France
| | - Mathieu Gissot
- CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, Center for Infection and Immunity of Lille, CIIL, Univ. Lille, Lille, France
| | - Olivier Silvie
- INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, Sorbonne Université, Paris, France
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40
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Fairweather SJ, Rajendran E, Blume M, Javed K, Steinhöfel B, McConville MJ, Kirk K, Bröer S, van Dooren GG. Coordinated action of multiple transporters in the acquisition of essential cationic amino acids by the intracellular parasite Toxoplasma gondii. PLoS Pathog 2021; 17:e1009835. [PMID: 34432856 PMCID: PMC8423306 DOI: 10.1371/journal.ppat.1009835] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 09/07/2021] [Accepted: 07/23/2021] [Indexed: 02/07/2023] Open
Abstract
Intracellular parasites of the phylum Apicomplexa are dependent on the scavenging of essential amino acids from their hosts. We previously identified a large family of apicomplexan-specific plasma membrane-localized amino acid transporters, the ApiATs, and showed that the Toxoplasma gondii transporter TgApiAT1 functions in the selective uptake of arginine. TgApiAT1 is essential for parasite virulence, but dispensable for parasite growth in medium containing high concentrations of arginine, indicating the presence of at least one other arginine transporter. Here we identify TgApiAT6-1 as the second arginine transporter. Using a combination of parasite assays and heterologous characterisation of TgApiAT6-1 in Xenopus laevis oocytes, we demonstrate that TgApiAT6-1 is a general cationic amino acid transporter that mediates both the high-affinity uptake of lysine and the low-affinity uptake of arginine. TgApiAT6-1 is the primary lysine transporter in the disease-causing tachyzoite stage of T. gondii and is essential for parasite proliferation. We demonstrate that the uptake of cationic amino acids by TgApiAT6-1 is ‘trans-stimulated’ by cationic and neutral amino acids and is likely promoted by an inwardly negative membrane potential. These findings demonstrate that T. gondii has evolved overlapping transport mechanisms for the uptake of essential cationic amino acids, and we draw together our findings into a comprehensive model that highlights the finely-tuned, regulated processes that mediate cationic amino acid scavenging by these intracellular parasites. The causative agent of toxoplasmosis, Toxoplasma gondii, is a versatile intracellular parasite that can proliferate within nucleated cells of warm-blooded organisms. In order to survive, T. gondii parasites must scavenge the cationic amino acids lysine and arginine from their hosts. In a previous study, we demonstrated that a plasma membrane-localized protein called TgApiAT1 facilitates the uptake of arginine into the parasite. We found that parasites lacking TgApiAT1 could proliferate when cultured in medium containing high concentrations of arginine, suggesting the existence of an additional uptake pathway for arginine. In the present study, we demonstrate that this second uptake pathway is mediated by TgApiAT6-1, a protein belonging to the same solute transporter family as TgApiAT1. We show that TgApiAT6-1 is the major lysine transporter of the parasite, and that it is critical for parasite proliferation. Furthermore, we demonstrate that TgApiAT6-1 can transport arginine into parasites under conditions in which arginine concentrations are high and lysine concentrations are comparatively lower. These data support a model for the finely-tuned acquisition of essential cationic amino acids that involves multiple transporters, and which likely contributes to these parasites being able to survive and proliferate within a wide variety of host cell types.
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Affiliation(s)
- Stephen J. Fairweather
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- * E-mail: (SJF); (GGvD)
| | - Esther Rajendran
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Martin Blume
- Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
- Robert Koch Institute, Berlin, Germany
| | - Kiran Javed
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Birte Steinhöfel
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- Humboldt University Berlin, Berlin, Germany
| | - Malcolm J. McConville
- Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Kiaran Kirk
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Stefan Bröer
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Giel G. van Dooren
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- * E-mail: (SJF); (GGvD)
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41
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Rajendran E, Clark M, Goulart C, Steinhöfel B, Tjhin ET, Gross S, Smith NC, Kirk K, van Dooren GG. Substrate-mediated regulation of the arginine transporter of Toxoplasma gondii. PLoS Pathog 2021; 17:e1009816. [PMID: 34352043 PMCID: PMC8370653 DOI: 10.1371/journal.ppat.1009816] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/17/2021] [Accepted: 07/22/2021] [Indexed: 12/13/2022] Open
Abstract
Intracellular parasites, such as the apicomplexan Toxoplasma gondii, are adept at scavenging nutrients from their host. However, there is little understanding of how parasites sense and respond to the changing nutrient environments they encounter during an infection. TgApiAT1, a member of the apicomplexan ApiAT family of amino acid transporters, is the major uptake route for the essential amino acid L-arginine (Arg) in T. gondii. Here, we show that the abundance of TgApiAT1, and hence the rate of uptake of Arg, is regulated by the availability of Arg in the parasite's external environment, increasing in response to decreased [Arg]. Using a luciferase-based 'biosensor' strain of T. gondii, we demonstrate that the expression of TgApiAT1 varies between different organs within the host, indicating that parasites are able to modulate TgApiAT1-dependent uptake of Arg as they encounter different nutrient environments in vivo. Finally, we show that Arg-dependent regulation of TgApiAT1 expression is post-transcriptional, mediated by an upstream open reading frame (uORF) in the TgApiAT1 transcript, and we provide evidence that the peptide encoded by this uORF is critical for mediating regulation. Together, our data reveal the mechanism by which an apicomplexan parasite responds to changes in the availability of a key nutrient.
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Affiliation(s)
- Esther Rajendran
- Research School of Biology, Australian National University, Canberra, Australia
| | - Morgan Clark
- Research School of Biology, Australian National University, Canberra, Australia
| | - Cibelly Goulart
- Research School of Biology, Australian National University, Canberra, Australia
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Birte Steinhöfel
- Research School of Biology, Australian National University, Canberra, Australia
| | - Erick T. Tjhin
- Research School of Biology, Australian National University, Canberra, Australia
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Simon Gross
- Research School of Biology, Australian National University, Canberra, Australia
| | - Nicholas C. Smith
- Research School of Biology, Australian National University, Canberra, Australia
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Kiaran Kirk
- Research School of Biology, Australian National University, Canberra, Australia
| | - Giel G. van Dooren
- Research School of Biology, Australian National University, Canberra, Australia
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42
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Using Diatom and Apicomplexan Models to Study the Heme Pathway of Chromera velia. Int J Mol Sci 2021; 22:ijms22126495. [PMID: 34204357 PMCID: PMC8233740 DOI: 10.3390/ijms22126495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/11/2021] [Accepted: 06/12/2021] [Indexed: 12/20/2022] Open
Abstract
Heme biosynthesis is essential for almost all living organisms. Despite its conserved function, the pathway’s enzymes can be located in a remarkable diversity of cellular compartments in different organisms. This location does not always reflect their evolutionary origins, as might be expected from the history of their acquisition through endosymbiosis. Instead, the final subcellular localization of the enzyme reflects multiple factors, including evolutionary origin, demand for the product, availability of the substrate, and mechanism of pathway regulation. The biosynthesis of heme in the apicomonad Chromera velia follows a chimeric pathway combining heme elements from the ancient algal symbiont and the host. Computational analyses using different algorithms predict complex targeting patterns, placing enzymes in the mitochondrion, plastid, endoplasmic reticulum, or the cytoplasm. We employed heterologous reporter gene expression in the apicomplexan parasite Toxoplasma gondii and the diatom Phaeodactylum tricornutum to experimentally test these predictions. 5-aminolevulinate synthase was located in the mitochondria in both transfection systems. In T. gondii, the two 5-aminolevulinate dehydratases were located in the cytosol, uroporphyrinogen synthase in the mitochondrion, and the two ferrochelatases in the plastid. In P. tricornutum, all remaining enzymes, from ALA-dehydratase to ferrochelatase, were placed either in the endoplasmic reticulum or in the periplastidial space.
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43
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Márquez-Nogueras KM, Hortua Triana MA, Chasen NM, Kuo IY, Moreno SN. Calcium signaling through a transient receptor channel is important for Toxoplasma gondii growth. eLife 2021; 10:63417. [PMID: 34106044 PMCID: PMC8216714 DOI: 10.7554/elife.63417] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 06/08/2021] [Indexed: 12/24/2022] Open
Abstract
Transient receptor potential (TRP) channels participate in calcium ion (Ca2+) influx and intracellular Ca2+ release. TRP channels have not been studied in Toxoplasma gondii or any other apicomplexan parasite. In this work, we characterize TgGT1_310560, a protein predicted to possess a TRP domain (TgTRPPL-2), and determined its role in Ca2+ signaling in T. gondii, the causative agent of toxoplasmosis. TgTRPPL-2 localizes to the plasma membrane and the endoplasmic reticulum (ER) of T. gondii. The ΔTgTRPPL-2 mutant was defective in growth and cytosolic Ca2+ influx from both extracellular and intracellular sources. Heterologous expression of TgTRPPL-2 in HEK-3KO cells allowed its functional characterization. Patching of ER-nuclear membranes demonstrates that TgTRPPL-2 is a non-selective cation channel that conducts Ca2+. Pharmacological blockers of TgTRPPL-2 inhibit Ca2+ influx and parasite growth. This is the first report of an apicomplexan ion channel that conducts Ca2+ and may initiate a Ca2+ signaling cascade that leads to the stimulation of motility, invasion, and egress. TgTRPPL-2 is a potential target for combating toxoplasmosis.
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Affiliation(s)
- Karla Marie Márquez-Nogueras
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, United States.,Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, United States
| | | | - Nathan M Chasen
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, United States
| | - Ivana Y Kuo
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, United States
| | - Silvia Nj Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, United States.,Department of Cellular Biology, University of Georgia, Athens, United States
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44
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Dass S, Shunmugam S, Berry L, Arnold CS, Katris NJ, Duley S, Pierrel F, Cesbron-Delauw MF, Yamaryo-Botté Y, Botté CY. Toxoplasma LIPIN is essential in channeling host lipid fluxes through membrane biogenesis and lipid storage. Nat Commun 2021; 12:2813. [PMID: 34001876 PMCID: PMC8129101 DOI: 10.1038/s41467-021-22956-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 03/24/2021] [Indexed: 01/20/2023] Open
Abstract
Apicomplexa are obligate intracellular parasites responsible for major human diseases. Their intracellular survival relies on intense lipid synthesis, which fuels membrane biogenesis. Parasite lipids are generated as an essential combination of fatty acids scavenged from the host and de novo synthesized within the parasite apicoplast. The molecular and metabolic mechanisms allowing regulation and channeling of these fatty acid fluxes for intracellular parasite survival are currently unknown. Here, we identify an essential phosphatidic acid phosphatase in Toxoplasma gondii, TgLIPIN, as the central metabolic nexus responsible for controlled lipid synthesis sustaining parasite development. Lipidomics reveal that TgLIPIN controls the synthesis of diacylglycerol and levels of phosphatidic acid that regulates the fine balance of lipids between storage and membrane biogenesis. Using fluxomic approaches, we uncover the first parasite host-scavenged lipidome and show that TgLIPIN prevents parasite death by 'lipotoxicity' through effective channeling of host-scavenged fatty acids to storage triacylglycerols and membrane phospholipids.
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Affiliation(s)
- Sheena Dass
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Serena Shunmugam
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Laurence Berry
- Laboratory of Pathogen Host Interactions, UMR 5235, Université de Montpellier, Montpellier, France
| | - Christophe-Sebastien Arnold
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Nicholas J Katris
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Samuel Duley
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Fabien Pierrel
- Université Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France
| | - Marie-France Cesbron-Delauw
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France
| | - Yoshiki Yamaryo-Botté
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France.
| | - Cyrille Y Botté
- Apicolipid Team, Institute for Advanced Biosciences, CNRS UMR5309, Université Grenoble Alpes, INSERM U1209, Grenoble, France.
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45
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Berná L, Marquez P, Cabrera A, Greif G, Francia ME, Robello C. Reevaluation of the Toxoplasma gondii and Neospora caninum genomes reveals misassembly, karyotype differences, and chromosomal rearrangements. Genome Res 2021; 31:823-833. [PMID: 33906964 PMCID: PMC8092007 DOI: 10.1101/gr.262832.120] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 12/16/2020] [Indexed: 12/14/2022]
Abstract
Neosporacaninum primarily infects cattle, causing abortions, with an estimated impact of a billion dollars on the worldwide economy annually. However, the study of its biology has been unheeded by the established paradigm that it is virtually identical to its close relative, the widely studied human pathogen Toxoplasma gondii. By revisiting the genome sequence, assembly, and annotation using third-generation sequencing technologies, here we show that the N. caninum genome was originally incorrectly assembled under the presumption of synteny with T. gondii. We show that major chromosomal rearrangements have occurred between these species. Importantly, we show that chromosomes originally named Chr VIIb and VIII are indeed fused, reducing the karyotype of both N. caninum and T. gondii to 13 chromosomes. We reannotate the N. caninum genome, revealing more than 500 new genes. We sequence and annotate the nonphotosynthetic plastid and mitochondrial genomes and show that although apicoplast genomes are virtually identical, high levels of gene fragmentation and reshuffling exist between species and strains. Our results correct assembly artifacts that are currently widely distributed in the genome database of N. caninum and T. gondii and, more importantly, highlight the mitochondria as a previously oversighted source of variability and pave the way for a change in the paradigm of synteny, encouraging rethinking the genome as basis of the comparative unique biology of these pathogens.
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Affiliation(s)
- Luisa Berná
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay
| | - Pablo Marquez
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay
| | - Andrés Cabrera
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay
| | - Gonzalo Greif
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay
| | - María E Francia
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay.,Departamento de Parasitología y Micología, Facultad de Medicina-Universidad de la República, 11600 Montevideo, Uruguay
| | - Carlos Robello
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay.,Departamento de Bioquímica, Facultad de Medicina-Universidad de la República, 11300 Montevideo, Uruguay
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46
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Stasic AJ, Dykes EJ, Cordeiro CD, Vella SA, Fazli MS, Quinn S, Docampo R, Moreno SNJ. Ca 2+ entry at the plasma membrane and uptake by acidic stores is regulated by the activity of the V-H + -ATPase in Toxoplasma gondii. Mol Microbiol 2021; 115:1054-1068. [PMID: 33793004 DOI: 10.1111/mmi.14722] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/21/2021] [Accepted: 03/26/2021] [Indexed: 12/14/2022]
Abstract
Ca2+ is a universal intracellular signal that regulates many cellular functions. In Toxoplasma gondii, the controlled influx of extracellular and intracellular Ca2+ into the cytosol initiates a signaling cascade that promotes pathogenic processes like tissue destruction and dissemination. In this work, we studied the role of proton transport in cytosolic Ca2+ homeostasis and the initiation of Ca2+ signaling. We used a T. gondii mutant of the V-H+ -ATPase, a pump previously shown to transport protons to the extracellular medium, and to control intracellular pH and membrane potential and we show that proton gradients are important for maintaining resting cytosolic Ca2+ at physiological levels and for Ca2+ influx. Proton transport was also important for Ca2+ storage by acidic stores and, unexpectedly, the endoplasmic reticulum. Proton transport impacted the amount of polyphosphate (polyP), a phosphate polymer that binds Ca2+ and concentrates in acidocalcisomes. This was supported by the co-localization of the vacuolar transporter chaperone 4 (VTC4), the catalytic subunit of the VTC complex that synthesizes polyP, with the V-ATPase in acidocalcisomes. Our work shows that proton transport regulates plasma membrane Ca2+ transport and control acidocalcisome polyP and Ca2+ content, impacting Ca2+ signaling and downstream stimulation of motility and egress in T. gondii.
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Affiliation(s)
- Andrew J Stasic
- Center for Tropical and Emerging Global Diseases, University of Georgia, Georgia, GA, USA
| | - Eric J Dykes
- Center for Tropical and Emerging Global Diseases, University of Georgia, Georgia, GA, USA.,Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Ciro D Cordeiro
- Center for Tropical and Emerging Global Diseases, University of Georgia, Georgia, GA, USA.,Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Stephen A Vella
- Center for Tropical and Emerging Global Diseases, University of Georgia, Georgia, GA, USA
| | - Mojtaba S Fazli
- Department of Computer Sciences, University of Georgia, Athens, GA, USA
| | - Shannon Quinn
- Department of Cellular Biology, University of Georgia, Athens, GA, USA.,Department of Computer Sciences, University of Georgia, Athens, GA, USA
| | - Roberto Docampo
- Center for Tropical and Emerging Global Diseases, University of Georgia, Georgia, GA, USA.,Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Silvia N J Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Georgia, GA, USA.,Department of Cellular Biology, University of Georgia, Athens, GA, USA
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47
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Aquilini E, Cova MM, Mageswaran SK, Dos Santos Pacheco N, Sparvoli D, Penarete-Vargas DM, Najm R, Graindorge A, Suarez C, Maynadier M, Berry-Sterkers L, Urbach S, Fahy PR, Guérin AN, Striepen B, Dubremetz JF, Chang YW, Turkewitz AP, Lebrun M. An Alveolata secretory machinery adapted to parasite host cell invasion. Nat Microbiol 2021; 6:425-434. [PMID: 33495622 PMCID: PMC8886610 DOI: 10.1038/s41564-020-00854-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 12/14/2020] [Indexed: 01/29/2023]
Abstract
Apicomplexa are unicellular eukaryotes and obligate intracellular parasites, including Plasmodium (the causative agent of malaria) and Toxoplasma (one of the most widespread zoonotic pathogens). Rhoptries, one of their specialized secretory organelles, undergo regulated exocytosis during invasion1. Rhoptry proteins are injected directly into the host cell to support invasion and subversion of host immune function2. The mechanism by which they are discharged is unclear and appears distinct from those in bacteria, yeast, animals and plants. Here, we show that rhoptry secretion in Apicomplexa shares structural and genetic elements with the exocytic machinery of ciliates, their free-living relatives. Rhoptry exocytosis depends on intramembranous particles in the shape of a rosette embedded into the plasma membrane of the parasite apex. Formation of this rosette requires multiple non-discharge (Nd) proteins conserved and restricted to Ciliata, Dinoflagellata and Apicomplexa that together constitute the superphylum Alveolata. We identified Nd6 at the site of exocytosis in association with an apical vesicle. Sandwiched between the rosette and the tip of the rhoptry, this vesicle appears as a central element of the rhoptry secretion machine. Our results describe a conserved secretion system that was adapted to provide defence for free-living unicellular eukaryotes and host cell injection in intracellular parasites.
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Affiliation(s)
- Eleonora Aquilini
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
| | - Marta Mendonça Cova
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
| | - Shrawan Kumar Mageswaran
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nicolas Dos Santos Pacheco
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
| | - Daniela Sparvoli
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | | | - Rania Najm
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
| | - Arnault Graindorge
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
| | - Catherine Suarez
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
| | - Marjorie Maynadier
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
| | - Laurence Berry-Sterkers
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
| | - Serge Urbach
- Institut de Génomique Fonctionnelle (IGF), Université de Montpellier, CNRS and INSERM, Montpellier, France
| | - Pilar Ruga Fahy
- Pôle Facultaire de Microscopie Ultrastructurale, Geneva, Switzerland
| | - Amandine N Guérin
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jean-François Dubremetz
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Aaron P Turkewitz
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | - Maryse Lebrun
- Laboratory of Pathogen Host Interactions UMR 5235, Université de Montpellier and CNRS, Montpellier, France.
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48
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Identifying the major lactate transporter of Toxoplasma gondii tachyzoites. Sci Rep 2021; 11:6787. [PMID: 33762657 PMCID: PMC7991638 DOI: 10.1038/s41598-021-86204-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 03/10/2021] [Indexed: 11/09/2022] Open
Abstract
Toxoplasma gondii and Plasmodium falciparum parasites both extrude l-lactate, a byproduct of glycolysis. The P. falciparum Formate Nitrite Transporter, PfFNT, mediates l-lactate transport across the plasma membrane of P. falciparum parasites and has been validated as a drug target. The T. gondii genome encodes three FNTs that have been shown to transport l-lactate, and which are proposed to be the targets of several inhibitors of T. gondii proliferation. Here, we show that each of the TgFNTs localize to the T. gondii plasma membrane and are capable of transporting l-lactate across it, with TgFNT1 making the primary contribution to l-lactate transport during the disease-causing lytic cycle of the parasite. We use the Xenopus oocyte expression system to provide direct measurements of l-lactate transport via TgFNT1. We undertake a genetic analysis of the importance of the tgfnt genes for parasite proliferation, and demonstrate that all three tgfnt genes can be disrupted individually and together without affecting the lytic cycle under in vitro culture conditions. Together, our experiments identify the major lactate transporter in the disease causing stage of T. gondii, and reveal that this transporter is not required for parasite proliferation, indicating that TgFNTs are unlikely to be targets for anti-Toxoplasma drugs.
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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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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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