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Affiliation(s)
- Michael J. Boucher
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
| | - Ellen Yeh
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
- Chan Zuckerberg Biohub, San Francisco, California, United States of America
- * E-mail:
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Chaudhari R, Dey V, Narayan A, Sharma S, Patankar S. Membrane and luminal proteins reach the apicoplast by different trafficking pathways in the malaria parasite Plasmodium falciparum. PeerJ 2017; 5:e3128. [PMID: 28462015 PMCID: PMC5410153 DOI: 10.7717/peerj.3128] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 02/27/2017] [Indexed: 01/12/2023] Open
Abstract
The secretory pathway in Plasmodium falciparum has evolved to transport proteins to the host cell membrane and to an endosymbiotic organelle, the apicoplast. The latter can occur via the ER or the ER-Golgi route. Here, we study these three routes using proteins Erythrocyte Membrane Protein-1 (PfEMP1), Acyl Carrier Protein (ACP) and glutathione peroxidase-like thioredoxin peroxidase (PfTPxGl) and inhibitors of vesicular transport. As expected, the G protein-dependent vesicular fusion inhibitor AlF4− and microtubule destabilizing drug vinblastine block the trafficking of PfEMP-1, a protein secreted to the host cell membrane. However, while both PfTPxGl and ACP are targeted to the apicoplast, only ACP trafficking remains unaffected by these treatments. This implies that G protein-dependent vesicles do not play a role in classical apicoplast protein targeting. Unlike the soluble protein ACP, we show that PfTPxGl is localized to the outermost membrane of the apicoplast. Thus, the parasite apicoplast acquires proteins via two different pathways: first, the vesicular trafficking pathway appears to handle not only secretory proteins, but an apicoplast membrane protein, PfTPxGl; second, trafficking of apicoplast luminal proteins appear to be independent of G protein-coupled vesicles.
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Affiliation(s)
- Rahul Chaudhari
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Vishakha Dey
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Mumbai, Maharashtra, India
| | - Aishwarya Narayan
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Mumbai, Maharashtra, India
| | - Shobhona Sharma
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Swati Patankar
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Mumbai, Maharashtra, India
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Lim L, Sayers CP, Goodman CD, McFadden GI. Targeting of a Transporter to the Outer Apicoplast Membrane in the Human Malaria Parasite Plasmodium falciparum. PLoS One 2016; 11:e0159603. [PMID: 27442138 PMCID: PMC4956234 DOI: 10.1371/journal.pone.0159603] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/05/2016] [Indexed: 01/08/2023] Open
Abstract
Apicoplasts are vestigial plastids in apicomplexan parasites like Plasmodium, the causative agent of malaria. Apicomplexan parasites are dependant on their apicoplasts for synthesis of various molecules that they are unable to scavenge in sufficient quantity from their host, which makes apicoplasts attractive drug targets. Proteins known as plastid phosphate translocators (pPTs) are embedded in the outer apicoplast membrane and are responsible for the import of carbon, energy and reducing power to drive anabolic synthesis in the organelle. We investigated how a pPT is targeted into the outer apicoplast membrane of the human malaria parasite P. falciparum. We showed that a transmembrane domain is likely to act as a recessed signal anchor to direct the protein into the endomembrane system, and that a tyrosine in the cytosolic N-terminus of the protein is essential for targeting, but one or more, as yet unidentified, factors are also essential to direct the protein into the outer apicoplast membrane.
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Affiliation(s)
- Liting Lim
- School of BioSciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Claire P. Sayers
- School of BioSciences, University of Melbourne, Melbourne, Victoria, Australia
| | | | - Geoffrey I. McFadden
- School of BioSciences, University of Melbourne, Melbourne, Victoria, Australia
- * E-mail:
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Toxoplasma gondii nucleus coding apicoplast protein ACP synthesis and trafficking in delayed death. Parasitol Res 2015; 114:1099-105. [PMID: 25563610 DOI: 10.1007/s00436-014-4281-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 12/16/2014] [Indexed: 01/14/2023]
Abstract
This study aimed to explore Toxoplasma gondii nucleus coding apicoplast protein acyl carrier protein (ACP) synthesis and trafficking in delayed death. The recombinant T. gondii ACP was expressed by prokaryotic expression method, and anti-ACP polyclonal antibody was obtained from rabbit immune. T. gondii "delayed death" was induced by clindamycin (CLDM), and ACP transcription was determined by real-time PCR assay. The expression of ACP with transit type (t-ACP) and mature type (m-ACP) was determined by Western blotting with anti-ACP polyclonal antibody. The mutant-expressed ACP fused with green fluorescent protein (GFP) tag was constructed by pHX-ACP-GFP. The distribution of ACP in "delayed death" was observed by ACP-GFP fusion protein with a confocal microscope. T. gondii ACP transcription and t-ACP expression had no significant decrease in the early 4 h of "delayed death," but there has been a significant decrease in 6 h. The expression of m-ACP had a significant decrease in 4 h which occurred earlier than the t-ACP expression. The number of brightly dot green fluorescence in ACP-GFP mutant decreased with prolonged time. There was very little brightly dot green fluorescence in ACP-GFP mutant when treated with CLDM for 6 h. CLDM could suppress apicoplast proliferation and induce T. gondii "delayed death"; however, it could not directly suppress nucleus coding ACP transcription and expression. T. gondii lacking of apicoplast had a barrier of transit peptide cleavage and t-ACP could not be transformed into m-ACP. The reason for the decrease in ACP expression could be due to excessive t-ACP synthesis in tachyzoites resulting in a negative feedback for the ACP coding gene transcription.
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Tawk L, Dubremetz JF, Montcourrier P, Chicanne G, Merezegue F, Richard V, Payrastre B, Meissner M, Vial HJ, Roy C, Wengelnik K, Lebrun M. Phosphatidylinositol 3-Monophosphate Is Involved in Toxoplasma Apicoplast Biogenesis. PLoS Pathog 2011; 7:e1001286. [PMID: 21379336 PMCID: PMC3040667 DOI: 10.1371/journal.ppat.1001286] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 01/10/2011] [Indexed: 12/14/2022] Open
Abstract
Apicomplexan parasites cause devastating diseases including malaria and toxoplasmosis. They harbour a plastid-like, non-photosynthetic organelle of algal origin, the apicoplast, which fulfils critical functions for parasite survival. Because of its essential and original metabolic pathways, the apicoplast has become a target for the development of new anti-apicomplexan drugs. Here we show that the lipid phosphatidylinositol 3-monophosphate (PI3P) is involved in apicoplast biogenesis in Toxoplasma gondii. In yeast and mammalian cells, PI3P is concentrated on early endosomes and regulates trafficking of endosomal compartments. Imaging of PI3P in T. gondii showed that the lipid was associated with the apicoplast and apicoplast protein-shuttling vesicles. Interference with regular PI3P function by over-expression of a PI3P specific binding module in the parasite led to the accumulation of vesicles containing apicoplast peripheral membrane proteins around the apicoplast and, ultimately, to the loss of the organelle. Accordingly, inhibition of the PI3P-synthesising kinase interfered with apicoplast biogenesis. These findings point to an unexpected implication for this ubiquitous lipid and open new perspectives on how nuclear encoded proteins traffic to the apicoplast. This study also highlights the possibility of developing specific pharmacological inhibitors of the parasite PI3-kinase as novel anti-apicomplexan drugs. Phosphatidyinositol 3-monophosphate (PI3P) is important for endocytic fusion events in eukaryotic cells. Despite the importance of this lipid in cell biology, its localization and function in apicomplexan parasites has not yet been extensively explored. In this study, we attribute for the first time a role for PI3P in Toxoplasma and identify a function different from classical endosomal trafficking. We show that the perturbation of PI3P function in T. gondii induced a morphological alteration of vesicles containing proteins destined for the outermost apicoplast membrane, which accumulated abnormally around the organelle, resulting ultimately in the loss of apicoplasts. These findings suggest a new role for PI3P in a vesicular trafficking process necessary for apicoplast biogenesis and provide an attractive model in which PI3P allows the fusion of vesicles containing nuclear-encoded apicoplast proteins with the apicoplast. As the outermost membrane of the apicoplast is originally derived from the endocytic compartment during the ancestral secondary endosymbiosis event, a fascinating question arises about whether apicomplexan parasites have reshaped the classical PI3P-dependent endocytic machinery to target proteins to the apicoplast.
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Affiliation(s)
- Lina Tawk
- UMR 5235 CNRS, Université Montpellier 1 & 2, Montpellier, France
| | | | | | - Gaëtan Chicanne
- INSERM U563, Université Toulouse III Paul-Sabatier, CHU Toulouse, Hôpital Purpan, Toulouse, France
| | | | - Véronique Richard
- Service Commun de Microscopie Electronique, Université de Montpellier 1 & 2, Montpellier, France
| | - Bernard Payrastre
- INSERM U563, Université Toulouse III Paul-Sabatier, CHU Toulouse, Hôpital Purpan, Toulouse, France
| | - Markus Meissner
- Faculty of Biomedical & Life Sciences, Parasitology, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, Scotland, United Kingdom
| | - Henri J. Vial
- UMR 5235 CNRS, Université Montpellier 1 & 2, Montpellier, France
| | - Christian Roy
- UMR 5235 CNRS, Université Montpellier 1 & 2, Montpellier, France
| | - Kai Wengelnik
- UMR 5235 CNRS, Université Montpellier 1 & 2, Montpellier, France
- * E-mail: (ML); (KW)
| | - Maryse Lebrun
- UMR 5235 CNRS, Université Montpellier 1 & 2, Montpellier, France
- * E-mail: (ML); (KW)
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Phosphatidylinositol 3-phosphate, an essential lipid in Plasmodium, localizes to the food vacuole membrane and the apicoplast. EUKARYOTIC CELL 2010; 9:1519-30. [PMID: 20709789 DOI: 10.1128/ec.00124-10] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phosphoinositides are important regulators of diverse cellular functions, and phosphatidylinositol 3-monophosphate (PI3P) is a key element in vesicular trafficking processes. During its intraerythrocytic development, the malaria parasite Plasmodium falciparum establishes a sophisticated but poorly characterized protein and lipid trafficking system. Here we established the detailed phosphoinositide profile of P. falciparum-infected erythrocytes and found abundant amounts of PI3P, while phosphatidylinositol 3,5-bisphosphate was not detected. PI3P production was parasite dependent, sensitive to a phosphatidylinositol-3-kinase (PI3-kinase) inhibitor, and predominant in late parasite stages. The Plasmodium genome encodes a class III PI3-kinase of unusual size, containing large insertions and several repetitive sequence motifs. The gene could not be deleted in Plasmodium berghei, and in vitro growth of P. falciparum was sensitive to a PI3-kinase inhibitor, indicating that PI3-kinase is essential in Plasmodium blood stages. For intraparasitic PI3P localization, transgenic P. falciparum that expressed a PI3P-specific fluorescent probe was generated. Fluorescence was associated mainly with the membrane of the food vacuole and with the apicoplast, a four-membrane bounded plastid-like organelle derived from an ancestral secondary endosymbiosis event. Electron microscopy analysis confirmed these findings and revealed, in addition, the presence of PI3P-positive single-membrane vesicles. We hypothesize that these vesicles might be involved in transport processes, likely of proteins and lipids, toward the essential and peculiar parasite compartment, which is the apicoplast. The fact that PI3P metabolism and function in Plasmodium appear to be substantially different from those in its human host could offer new possibilities for antimalarial chemotherapy.
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Abstract
Most Apicomplexans possess a relic plastid named apicoplast, originating from secondary endosymbiosis of a red algae. This non-photosynthetic organelle fulfils important metabolic functions and confers sensitivity to antibiotics. The tasks of this organelle is compared across the phylum of Apicomplexa, highlighting its role in metabolic adaptation to different intracellular niches.
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Seeber F, Soldati-Favre D. Metabolic Pathways in the Apicoplast of Apicomplexa. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 281:161-228. [DOI: 10.1016/s1937-6448(10)81005-6] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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