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Renaud EA, Maupin AJM, Bordat Y, Graindorge A, Berry L, Besteiro S. Iron depletion has different consequences on the growth and survival of Toxoplasma gondii strains. Virulence 2024; 15:2329566. [PMID: 38509723 PMCID: PMC10962585 DOI: 10.1080/21505594.2024.2329566] [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: 12/29/2023] [Accepted: 03/07/2024] [Indexed: 03/22/2024] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite responsible for a pathology called toxoplasmosis, which primarily affects immunocompromised individuals and developing foetuses. The parasite can scavenge essential nutrients from its host to support its growth and survival. Among them, iron is one of the most important elements needed to sustain basic cellular functions as it is involved in a number of key metabolic processes, including oxygen transport, redox balance, and electron transport. We evaluated the effects of an iron chelator on the development of several parasite strains and found that they differed in their ability to tolerate iron depletion. The growth of parasites usually associated with a model of acute toxoplasmosis was strongly affected by iron depletion, whereas cystogenic strains were less sensitive as they were able to convert into persisting developmental forms that are associated with the chronic form of the disease. Ultrastructural and biochemical characterization of the impact of iron depletion on parasites also highlighted striking changes in both their metabolism and that of the host, with a marked accumulation of lipid droplets and perturbation of lipid homoeostasis. Overall, our study demonstrates that although acute iron depletion has an important effect on the growth of T. gondii, it has a more profound impact on actively dividing parasites, whereas less metabolically active parasite forms may be able to avoid some of the most detrimental consequences.
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Affiliation(s)
- Eléa A. Renaud
- LPHI, University Montpellier, Inserm, CNRS, Montpellier, France
| | | | - Yann Bordat
- LPHI, University Montpellier, Inserm, CNRS, Montpellier, France
| | | | - Laurence Berry
- LPHI, University Montpellier, Inserm, CNRS, Montpellier, France
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Loveridge KM, Sigala PA. Identification of a divalent metal transporter required for cellular iron metabolism in malaria parasites. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.10.587216. [PMID: 38798484 PMCID: PMC11118319 DOI: 10.1101/2024.05.10.587216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Plasmodium falciparum malaria parasites invade and multiply inside red blood cells (RBCs), the most iron-rich compartment in humans. Like all cells, P. falciparum requires nutritional iron to support essential metabolic pathways, but the critical mechanisms of iron acquisition and trafficking during RBC infection have remained obscure. Parasites internalize and liberate massive amounts of heme during large-scale digestion of RBC hemoglobin within an acidic food vacuole (FV) but lack a heme oxygenase to release porphyrin-bound iron. Although most FV heme is sequestered into inert hemozoin crystals, prior studies indicate that trace heme escapes biomineralization and is susceptible to non-enzymatic degradation within the oxidizing FV environment to release labile iron. Parasites retain a homolog of divalent metal transporter 1 (DMT1), a known mammalian iron transporter, but its role in P. falciparum iron acquisition has not been tested. Our phylogenetic studies indicate that P. falciparum DMT1 (PfDMT1) retains conserved molecular features critical for metal transport. We localized this protein to the FV membrane and defined its orientation in an export-competent topology. Conditional knockdown of PfDMT1 expression is lethal to parasites, which display broad cellular defects in iron-dependent functions, including impaired apicoplast biogenesis and mitochondrial polarization. Parasites are selectively rescued from partial PfDMT1 knockdown by supplementation with exogenous iron, but not other metals. These results support a cellular paradigm whereby PfDMT1 is the molecular gatekeeper to essential iron acquisition by blood-stage malaria parasites and suggest that therapeutic targeting of PfDMT1 may be a potent antimalarial strategy.
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Affiliation(s)
- Kade M. Loveridge
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Paul A. Sigala
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, United States
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Fang T, Mohseni A, Lonardi S, Ben Mamoun C. Properties and predicted functions of large genes and proteins of apicomplexan parasites. NAR Genom Bioinform 2024; 6:lqae032. [PMID: 38584870 PMCID: PMC10993292 DOI: 10.1093/nargab/lqae032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/23/2024] [Accepted: 03/20/2024] [Indexed: 04/09/2024] Open
Abstract
Evolutionary constraints greatly favor compact genomes that efficiently encode proteins. However, several eukaryotic organisms, including apicomplexan parasites such as Toxoplasma gondii, Plasmodium falciparum and Babesia duncani, the causative agents of toxoplasmosis, malaria and babesiosis, respectively, encode very large proteins, exceeding 20 times their average protein size. Although these large proteins represent <1% of the total protein pool and are generally expressed at low levels, their persistence throughout evolution raises important questions about their functions and possible evolutionary pressures to maintain them. In this study, we examined the trends in gene and protein size, function and expression patterns within seven apicomplexan pathogens. Our analysis revealed that certain large proteins in apicomplexan parasites harbor domains potentially important for functions such as antigenic variation, erythrocyte invasion and immune evasion. However, these domains are not limited to or strictly conserved within large proteins. While some of these proteins are predicted to engage in conventional metabolic pathways within these parasites, others fulfill specialized functions for pathogen-host interactions, nutrient acquisition and overall survival.
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Affiliation(s)
- Tiffany Fang
- Department of Internal Medicine, Section of Infectious Diseases, Department of Microbial Pathogenesis and Department of Pathology, Yale School of Medicine, New Haven, CT, 06520 USA
| | - Amir Mohseni
- Department of Computer Science and Engineering, University of California, Riverside, CA, 92521 USA
| | - Stefano Lonardi
- Department of Computer Science and Engineering, University of California, Riverside, CA, 92521 USA
| | - Choukri Ben Mamoun
- Department of Internal Medicine, Section of Infectious Diseases, Department of Microbial Pathogenesis and Department of Pathology, Yale School of Medicine, New Haven, CT, 06520 USA
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Shrivastava D, Jha A, Kabrambam R, Vishwakarma J, Mitra K, Ramachandran R, Habib S. Plasmodium falciparum ZIP1 Is a Zinc-Selective Transporter with Stage-Dependent Targeting to the Apicoplast and Plasma Membrane in Erythrocytic Parasites. ACS Infect Dis 2024; 10:155-169. [PMID: 38163252 DOI: 10.1021/acsinfecdis.3c00426] [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] [Indexed: 01/03/2024]
Abstract
Replication of the malarial parasite in human erythrocytes requires massive zinc fluxes, necessitating the action of zinc transporters across the parasite plasma and organellar membranes. Although genetic knockout studies have been conducted on a few "orphan" zinc transporters in Plasmodium spp., none of them have been functionally characterized. We used the recombinant Plasmodium falciparum Zrt-/Irt-like protein (PfZIP1) and specific antibodies generated against it to explore the subcellular localization, function, metal-ion selectivity, and response to cellular zinc levels. PfZIP1 expression was enhanced upon the depletion of cytosolic Zn2+. The protein transitioned from the processed to unprocessed form through blood stages, localizing to the apicoplast in trophozoites and to the parasite plasma membrane in schizonts and gametocytes, indicating stage-specific functional role. The PfZIP1 dimer mediated Zn2+ influx in proteoliposomes. It exhibited preferential binding to Zn2+ compared to Fe2+, with the selectivity for zinc being driven by a C-terminal histidine-rich region conserved only in primate-infecting Plasmodium species.
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Affiliation(s)
- Deepti Shrivastava
- Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Lucknow 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Akanksha Jha
- Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Rajlakshmi Kabrambam
- Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Lucknow 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Jyoti Vishwakarma
- Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Kalyan Mitra
- Sophisticated Analytical Instrument Facility and Research Division, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Ravishankar Ramachandran
- Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Saman Habib
- Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Lucknow 226031, India
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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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Djoko K, Cavet J. Perspectives on Metals in Microbiology. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35786425 DOI: 10.1099/mic.0.001215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Karrera Djoko
- Department of Biosciences, Durham University, Durham, UK
| | - Jennifer Cavet
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
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Thomas GH. Microbial Musings – December 2021. Microbiology (Reading) 2021; 167. [PMID: 35099370 PMCID: PMC8914246 DOI: 10.1099/mic.0.001141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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