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Gilson PR, Chisholm SA, Crabb BS, de Koning-Ward TF. Host cell remodelling in malaria parasites: a new pool of potential drug targets. Int J Parasitol 2016; 47:119-127. [PMID: 27368610 DOI: 10.1016/j.ijpara.2016.06.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/02/2016] [Accepted: 06/04/2016] [Indexed: 12/01/2022]
Abstract
When in their human hosts, malaria parasites spend most of their time housed within vacuoles inside erythrocytes and hepatocytes. The parasites extensively modify their host cells to obtain nutrients, prevent host cell breakdown and avoid the immune system. To perform these modifications, malaria parasites export hundreds of effector proteins into their host cells and this process is best understood in the most lethal species to infect humans, Plasmodium falciparum. The effector proteins are synthesized within the parasite and following a proteolytic cleavage event in the endoplasmic reticulum and sorting of mature proteins into the correct vesicular trafficking pathway, they are transported to the parasite surface and released into the vacuole. The effector proteins are then unfolded before extrusion across the vacuole membrane by a unique translocon complex called Plasmodium translocon of exported proteins. After gaining access to the erythrocyte cytoplasm many effector proteins continue their journey to the erythrocyte surface by utilising various membranous structures established by the parasite. This complex trafficking pathway and a large number of the effector proteins are unique to Plasmodium parasites. This pathway could, therefore, be developed as new drug targets given that protein export and the functional role of these proteins are essential for parasite survival. This review explores known and potential drug targetable steps in the protein export pathway and strategies for discovering novel drug targets.
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Affiliation(s)
- Paul R Gilson
- Burnet Institute, Melbourne, Victoria, Australia; Monash University, Melbourne, Victoria, Australia.
| | | | - Brendan S Crabb
- Burnet Institute, Melbourne, Victoria, Australia; Monash University, Melbourne, Victoria, Australia; University of Melbourne, Melbourne, Victoria, Australia
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Petersen W, Külzer S, Engels S, Zhang Q, Ingmundson A, Rug M, Maier AG, Przyborski JM. J-dot targeting of an exported HSP40 in Plasmodium falciparum-infected erythrocytes. Int J Parasitol 2016; 46:519-25. [PMID: 27063072 DOI: 10.1016/j.ijpara.2016.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 03/14/2016] [Accepted: 03/16/2016] [Indexed: 10/22/2022]
Abstract
Plasmodium falciparum exports a large number of proteins to its host cell, the mature human erythrocyte, where they are involved in host cell modification. Amongst the proteins trafficked to the host cell, many are heat shock protein (HSP)40 homologues. We previously demonstrated that at least two exported PfHSP40s (referred to as PFE55 and PFA660) localise to mobile structures in the P. falciparum-infected erythrocyte (Kulzer et al., 2010), termed J-dots. The complete molecular content of these structures has not yet been completely resolved, however it is known that they also contain an exported HSP70, PfHSP70x, and are potentially involved in transport of the major cytoadherance ligand, PfEMP1, through the host cell. To understand more about the nature of the association of exported HSP40s with J-dots, here we have studied the signal requirements for recruitment of the proteins to these structures. By expressing various exported GFP chimeras, we can demonstrate that the predicted substrate binding domain is necessary and sufficient for J-dot targeting. This targeting only occurs in human erythrocytes infected with P. falciparum, as it is not conserved when expressing a P. falciparum HSP40 in Plasmodium berghei-infected murine red blood cells, suggesting that J-dots are P. falciparum-specific. This data reveals a new mechanism for targeting of exported proteins to intracellular structures in the P. falciparum-infected erythrocyte.
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Affiliation(s)
- Wiebke Petersen
- Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany; Parasitology, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany; Molecular Parasitology, Humboldt University, Philippstrasse 13, 10115 Berlin, Germany
| | - Simone Külzer
- Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany; Research School of Biology, 134 Linnaeus Way, The Australian National University, Canberra, ACT 2601, Australia
| | - Sonja Engels
- Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany
| | - Qi Zhang
- Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany
| | - Alyssa Ingmundson
- Parasitology, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany; Molecular Parasitology, Humboldt University, Philippstrasse 13, 10115 Berlin, Germany
| | - Melanie Rug
- Centre for Advanced Microscopy, 131 Garran Road, The Australian National University, Canberra, ACT 2601, Australia
| | - Alexander G Maier
- Research School of Biology, 134 Linnaeus Way, The Australian National University, Canberra, ACT 2601, Australia
| | - Jude M Przyborski
- Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany.
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Moreira CK, Naissant B, Coppi A, Bennett BL, Aime E, Franke-Fayard B, Janse CJ, Coppens I, Sinnis P, Templeton TJ. The Plasmodium PHIST and RESA-Like Protein Families of Human and Rodent Malaria Parasites. PLoS One 2016; 11:e0152510. [PMID: 27022937 PMCID: PMC4811531 DOI: 10.1371/journal.pone.0152510] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 03/15/2016] [Indexed: 11/19/2022] Open
Abstract
The phist gene family has members identified across the Plasmodium genus, defined by the presence of a domain of roughly 150 amino acids having conserved aromatic residues and an all alpha-helical structure. The family is highly amplified in P. falciparum, with 65 predicted genes in the genome of the 3D7 isolate. In contrast, in the rodent malaria parasite P. berghei 3 genes are identified, one of which is an apparent pseudogene. Transcripts of the P. berghei phist genes are predominant in schizonts, whereas in P. falciparum transcript profiles span different asexual blood stages and gametocytes. We pursued targeted disruption of P. berghei phist genes in order to characterize a simplistic model for the expanded phist gene repertoire in P. falciparum. Unsuccessful attempts to disrupt P. berghei PBANKA_114540 suggest that this phist gene is essential, while knockout of phist PBANKA_122900 shows an apparent normal progression and non-essential function throughout the life cycle. Epitope-tagging of P. falciparum and P. berghei phist genes confirmed protein export to the erythrocyte cytoplasm and localization with a punctate pattern. Three P. berghei PEXEL/HT-positive exported proteins exhibit at least partial co-localization, in support of a common vesicular compartment in the cytoplasm of erythrocytes infected with rodent malaria parasites.
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Affiliation(s)
- Cristina K. Moreira
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10021, United States of America
| | - Bernina Naissant
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10021, United States of America
| | - Alida Coppi
- Department of Medical Parasitology, NYU School of Medicine, New York, NY, 10010, United States of America
| | - Brandy L. Bennett
- Department of Medical Parasitology, NYU School of Medicine, New York, NY, 10010, United States of America
| | - Elena Aime
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Blandine Franke-Fayard
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Chris J. Janse
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, United States of America
| | - Photini Sinnis
- Department of Medical Parasitology, NYU School of Medicine, New York, NY, 10010, United States of America
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, United States of America
| | - Thomas J. Templeton
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10021, United States of America
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki 852-8523, Japan
- * E-mail:
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Clinical manifestations and molecular mechanisms in the changing paradigm of vivax malaria in India. INFECTION GENETICS AND EVOLUTION 2016; 39:317-324. [PMID: 26876067 DOI: 10.1016/j.meegid.2016.02.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/14/2016] [Accepted: 02/09/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND Plasmodium vivax once considered benign is now being increasingly associated with complicated malaria where the spectrum of complications is vast and like Plasmodium falciparum. The clinical data is important with respect to the immunopathological status of the patient. Several genes like the vir genes and pvcrt-o are speculated to be attributing to the severity of P. vivax malaria. METHODS In the present study we carried out the transcription analysis of five vir genes (vir 14-related, vir 12, vir 17-like, putative vir 14 and vir 10-related) and pvcrt-o gene in severe (n=12) and non-severe (n=7) P. vivax clinical infections and studied the correlation of these genes with clinical disease severity. RESULTS This study revealed multiorgan involvement in severe vivax cases with severe thrombocytopenia and anemia, the predominantly occurring symptoms. Four out of five vir genes and pvcrt-o showed a significant increase in expression levels of severe infections compared to the non-severe infections indicating their possible role in the changing pathogenesis of P. vivax. CONCLUSIONS The increased virulence in vivax malaria seems to be the result of multifactorial parameters changing it phenotypically as well as genotypically. However more studies are needed to understand the still nascent severity of P. vivax malaria.
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Daniyan MO, Boshoff A, Prinsloo E, Pesce ER, Blatch GL. The Malarial Exported PFA0660w Is an Hsp40 Co-Chaperone of PfHsp70-x. PLoS One 2016; 11:e0148517. [PMID: 26845441 PMCID: PMC4742251 DOI: 10.1371/journal.pone.0148517] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 01/19/2016] [Indexed: 11/18/2022] Open
Abstract
Plasmodium falciparum, the human pathogen responsible for the most dangerous malaria infection, survives and develops in mature erythrocytes through the export of proteins needed for remodelling of the host cell. Molecular chaperones of the heat shock protein (Hsp) family are prominent members of the exportome, including a number of Hsp40s and a Hsp70. PFA0660w, a type II Hsp40, has been shown to be exported and possibly form a complex with PfHsp70-x in the infected erythrocyte cytosol. However, the chaperone properties of PFA0660w and its interaction with human and parasite Hsp70s are yet to be investigated. Recombinant PFA0660w was found to exist as a monomer in solution, and was able to significantly stimulate the ATPase activity of PfHsp70-x but not that of a second plasmodial Hsp70 (PfHsp70-1) or a human Hsp70 (HSPA1A), indicating a potential specific functional partnership with PfHsp70-x. Protein binding studies in the presence and absence of ATP suggested that the interaction of PFA0660w with PfHsp70-x most likely represented a co-chaperone/chaperone interaction. Also, PFA0660w alone produced a concentration-dependent suppression of rhodanese aggregation, demonstrating its chaperone properties. Overall, we have provided the first biochemical evidence for the possible role of PFA0660w as a chaperone and as co-chaperone of PfHsp70-x. We propose that these chaperones boost the chaperone power of the infected erythrocyte, enabling successful protein trafficking and folding, and thereby making a fundamental contribution to the pathology of malaria.
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Affiliation(s)
- Michael O. Daniyan
- Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
- Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Aileen Boshoff
- Biotechnology Innovation Centre, Rhodes University, Grahamstown, South Africa
| | - Earl Prinsloo
- Biotechnology Innovation Centre, Rhodes University, Grahamstown, South Africa
| | - Eva-Rachele Pesce
- Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- * E-mail: (GLB); (E-RP)
| | - Gregory L. Blatch
- Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- * E-mail: (GLB); (E-RP)
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Lo Presti L, López Díaz C, Turrà D, Di Pietro A, Hampel M, Heimel K, Kahmann R. A conserved co-chaperone is required for virulence in fungal plant pathogens. THE NEW PHYTOLOGIST 2016; 209:1135-1148. [PMID: 26487566 DOI: 10.1111/nph.13703] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/04/2015] [Indexed: 06/05/2023]
Abstract
The maize pathogenic fungus Ustilago maydis experiences endoplasmic reticulum (ER) stress during plant colonization and relies on the unfolded protein response (UPR) to cope with this stress. We identified the U. maydis co-chaperone, designated Dnj1, as part of this conserved cellular response to ER stress. ∆dnj1 cells are sensitive to the ER stressor tunicamycin and display a severe virulence defect in maize infection assays. A dnj1 mutant allele unable to stimulate the ATPase activity of chaperones phenocopies the null allele. A Dnj1-mCherry fusion protein localizes in the ER and interacts with the luminal chaperone Bip1. The Fusarium oxysporum Dnj1 ortholog contributes to the virulence of this fungal pathogen in tomato plants. Unlike the human ortholog, F. oxysporum Dnj1 partially rescues the virulence defect of the Ustilago dnj1 mutant. By enabling the fungus to restore ER homeostasis and maintain a high secretory activity, Dnj1 contributes to the establishment of a compatible interaction with the host. Dnj1 orthologs are present in many filamentous fungi, but are absent in budding and fission yeasts. We postulate a conserved and essential role during virulence for this class of co-chaperones.
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Affiliation(s)
- Libera Lo Presti
- Max Planck Institute for Terrestrial Microbiology, Karl-von Frisch-Strasse 10, 35043, Marburg, Germany
| | - Cristina López Díaz
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071, Cordoba, Spain
| | - David Turrà
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071, Cordoba, Spain
| | - Antonio Di Pietro
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, 14071, Cordoba, Spain
| | - Martin Hampel
- Department of Molecular Microbiology and Genetics, Georg-August-Universität Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany
| | - Kai Heimel
- Department of Molecular Microbiology and Genetics, Georg-August-Universität Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany
| | - Regine Kahmann
- Max Planck Institute for Terrestrial Microbiology, Karl-von Frisch-Strasse 10, 35043, Marburg, Germany
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Malaria Parasite Proteins and Their Role in Alteration of the Structure and Function of Red Blood Cells. ADVANCES IN PARASITOLOGY 2015; 91:1-86. [PMID: 27015947 DOI: 10.1016/bs.apar.2015.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Malaria, caused by Plasmodium spp., continues to be a major threat to human health and a significant cause of socioeconomic hardship in many countries. Almost half of the world's population live in malaria-endemic regions and many of them suffer one or more, often life-threatening episodes of malaria every year, the symptoms of which are attributable to replication of the parasite within red blood cells (RBCs). In the case of Plasmodium falciparum, the species responsible for most malaria-related deaths, parasite replication within RBCs is accompanied by striking alterations to the morphological, biochemical and biophysical properties of the host cell that are essential for the parasites' survival. To achieve this, the parasite establishes a unique and extensive protein export network in the infected RBC, dedicating at least 6% of its genome to the process. Understanding the full gamut of proteins involved in this process and the mechanisms by which P. falciparum alters the structure and function of RBCs is important both for a more complete understanding of the pathogenesis of malaria and for development of new therapeutic strategies to prevent or treat this devastating disease. This review focuses on what is currently known about exported parasite proteins, their interactions with the RBC and their likely pathophysiological consequences.
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Abstract
Plasmodium falciparum is the protozoan parasite that causes most malaria-associated morbidity and mortality in humans with over 500,000 deaths annually. The disease symptoms are associated with repeated cycles of invasion and asexual multiplication inside red blood cells of the parasite. Partial, non-sterile immunity to P. falciparum malaria develops only after repeated infections and continuous exposure. The successful evasion of the human immune system relies on the large repertoire of antigenically diverse parasite proteins displayed on the red blood cell surface and on the merozoite membrane where they are exposed to the human immune system. Expression switching of these polymorphic proteins between asexual parasite generations provides an efficient mechanism to adapt to the changing environment in the host and to maintain chronic infection. This chapter discusses antigenic diversity and variation in the malaria parasite and our current understanding of the molecular mechanisms that direct the expression of these proteins.
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Affiliation(s)
- Michaela Petter
- Department of Medicine Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, 792 Elizabeth Street, Melbourne, VIC, 3010, Australia.
| | - Michael F Duffy
- Department of Medicine Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, 792 Elizabeth Street, Melbourne, VIC, 3010, Australia.
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Spielmann T, Gilberger TW. Critical Steps in Protein Export of Plasmodium falciparum Blood Stages. Trends Parasitol 2015; 31:514-525. [DOI: 10.1016/j.pt.2015.06.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/16/2015] [Accepted: 06/24/2015] [Indexed: 11/29/2022]
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Baumeister S, Gangopadhyay P, Repnik U, Lingelbach K. Novel insights into red blood cell physiology using parasites as tools. Eur J Cell Biol 2015; 94:332-9. [DOI: 10.1016/j.ejcb.2015.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Przyborski JM, Diehl M, Blatch GL. Plasmodial HSP70s are functionally adapted to the malaria parasite life cycle. Front Mol Biosci 2015; 2:34. [PMID: 26167469 PMCID: PMC4481151 DOI: 10.3389/fmolb.2015.00034] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 06/12/2015] [Indexed: 11/13/2022] Open
Abstract
The human malaria parasite, Plasmodium falciparum, encodes a minimal complement of six heat shock protein 70s (PfHSP70s), some of which are highly expressed and are thought to play an important role in the survival and pathology of the parasite. In addition to canonical features of molecular chaperones, these HSP70s possess properties that reflect functional adaptation to a parasitic life style, including resistance to thermal insult during fever periods and host–parasite interactions. The parasite even exports an HSP70 to the host cell where it is likely to be involved in host cell modification. This review focuses on the features of the PfHSP70s, particularly with respect to their adaptation to the malaria parasite life cycle.
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Affiliation(s)
| | - Mathias Diehl
- Parasitology, Philipps University Marburg Marburg, Germany
| | - Gregory L Blatch
- Centre for Chronic Disease Prevention and Management, College of Health and Biomedicine, Victoria University Melbourne, VIC, Australia ; Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes University Grahamstown, South Africa
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Cockburn IL, Boshoff A, Pesce ER, Blatch GL. Selective modulation of plasmodial Hsp70s by small molecules with antimalarial activity. Biol Chem 2015; 395:1353-62. [PMID: 24854538 DOI: 10.1515/hsz-2014-0138] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Accepted: 04/12/2014] [Indexed: 11/15/2022]
Abstract
Plasmodial heat shock protein 70 (Hsp70) chaperones represent a promising new class of antimalarial drug targets because of the important roles they play in the survival and pathogenesis of the malaria parasite Plasmodium falciparum. This study assessed a set of small molecules (lapachol, bromo-β-lapachona and malonganenones A, B and C) as potential modulators of two biologically important plasmodial Hsp70s, the parasite-resident PfHsp70-1 and the exported PfHsp70-x. Compounds of interest were assessed for modulatory effects on the steady-state basal and heat shock protein 40 (Hsp40)-stimulated ATPase activities of PfHsp70-1, PfHsp70-x and human Hsp70, as well as on the protein aggregation suppression activity of PfHsp70-x. The antimalarial marine alkaloid malonganenone A was of particular interest, as it was found to have limited cytotoxicity to mammalian cell lines and exhibited the desired properties of an effective plasmodial Hsp70 modulator. This compound was found to inhibit plasmodial and not human Hsp70 ATPase activity (Hsp40-stimulated), and hindered the aggregation suppression activity of PfHsp70-x. Furthermore, malonganenone A was shown to disrupt the interaction between PfHsp70-x and Hsp40. This is the first report to show that PfHsp70-x has chaperone activity, is stimulated by Hsp40 and can be specifically modulated by small molecule compounds.
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63
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Kaushansky A, Kappe SH. Selection and refinement: the malaria parasite's infection and exploitation of host hepatocytes. Curr Opin Microbiol 2015; 26:71-8. [PMID: 26102161 DOI: 10.1016/j.mib.2015.05.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/16/2015] [Accepted: 05/22/2015] [Indexed: 01/23/2023]
Abstract
Plasmodium parasites belong to the Apicomplexan phylum, which consists mostly of obligate intracellular pathogens that vary dramatically in host cell tropism. Plasmodium sporozoites are highly hepatophilic. The specific molecular mechanisms, which facilitate sporozoite selection and successful infection of hepatocytes, remain poorly defined. Here, we discuss the parasite and host factors which are critical to hepatocyte infection. We derive a model where sporozoites initially select host cells that constitute a permissive environment and then further refine the chosen hepatocyte during liver stage development, ensuring life cycle progression. While many unknowns of pre-erythrocytic infection remain, advancing models and technologies that enable analysis of human malaria parasites and of single infected cells will catalyze a comprehensive understanding of the interaction between the malaria parasite and its hepatocyte host.
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Affiliation(s)
- Alexis Kaushansky
- Center for Infectious Disease Research, Formerly Seattle Biomedical Research Institute, 307 Westlake Ave. N, #500, Seattle, WA 98109, United States.
| | - Stefan Hi Kappe
- Center for Infectious Disease Research, Formerly Seattle Biomedical Research Institute, 307 Westlake Ave. N, #500, Seattle, WA 98109, United States; Department of Global Health, University of Washington, Seattle, WA, United States.
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Schulze J, Kwiatkowski M, Borner J, Schlüter H, Bruchhaus I, Burmester T, Spielmann T, Pick C. The Plasmodium falciparum exportome contains non-canonical PEXEL/HT proteins. Mol Microbiol 2015; 97:301-14. [PMID: 25850860 DOI: 10.1111/mmi.13024] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2015] [Indexed: 11/29/2022]
Abstract
The pathogenicity of Plasmodium falciparum is partly due to parasite-induced host cell modifications. These modifications are facilitated by exported P. falciparum proteins, collectively referred to as the exportome. Export of several hundred proteins is mediated by the PEXEL/HT, a protease cleavage site. The PEXEL/HT is usually comprised of five amino acids, of which R at position 1, L at position 3 and E, D or Q at position 5 are conserved and important for export. Non-canonical PEXEL/HTs with K or H at position 1 and/or I at position 3 are presently considered non-functional. Here, we show that non-canonical PEXEL/HT proteins are overrepresented in P. falciparum and other Plasmodium species. Furthermore, we show that non-canonical PEXEL/HTs can be cleaved and can promote export in both a REX3 and a GBP reporter, but not in a KAHRP reporter, indicating that non-canonical PEXEL/HTs are functional in concert with a supportive sequence environment. We then selected P. falciparum proteins with a non-canonical PEXEL/HT and show that some of these proteins are exported and that their export depends on non-canonical PEXEL/HTs. We conclude that PEXEL/HT plasticity is higher than appreciated and that non-canonical PEXEL/HT proteins cannot categorically be excluded from Plasmodium exportome predictions.
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Affiliation(s)
- Jana Schulze
- University of Hamburg, Institute of Zoology, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany
| | - Marcel Kwiatkowski
- Department of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, D-20246, Hamburg, Germany
| | - Janus Borner
- University of Hamburg, Institute of Zoology, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany
| | - Hartmut Schlüter
- Department of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, D-20246, Hamburg, Germany
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359, Hamburg, Germany
| | - Thorsten Burmester
- University of Hamburg, Institute of Zoology, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany
| | - Tobias Spielmann
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359, Hamburg, Germany
| | - Christian Pick
- University of Hamburg, Institute of Zoology, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany
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65
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Mbengue A, Vialla E, Berry L, Fall G, Audiger N, Demettre-Verceil E, Boteller D, Braun-Breton C. New Export Pathway inPlasmodium falciparum-Infected Erythrocytes: Role of the Parasite Group II Chaperonin, PfTRiC. Traffic 2015; 16:461-75. [DOI: 10.1111/tra.12266] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 01/20/2015] [Accepted: 01/21/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Alassane Mbengue
- University Montpellier II; CNRS UMR 5235, University Montpellier I; Dynamique des Interactions Membranaires Normales et Pathologiques 34095 Montpellier Cedex 5 France
| | - Emilie Vialla
- University Montpellier II; CNRS UMR 5235, University Montpellier I; Dynamique des Interactions Membranaires Normales et Pathologiques 34095 Montpellier Cedex 5 France
| | - Laurence Berry
- University Montpellier II; CNRS UMR 5235, University Montpellier I; Dynamique des Interactions Membranaires Normales et Pathologiques 34095 Montpellier Cedex 5 France
| | - Gamou Fall
- University Montpellier II; CNRS UMR 5235, University Montpellier I; Dynamique des Interactions Membranaires Normales et Pathologiques 34095 Montpellier Cedex 5 France
| | - Nicolas Audiger
- University Montpellier II; CNRS UMR 5235, University Montpellier I; Dynamique des Interactions Membranaires Normales et Pathologiques 34095 Montpellier Cedex 5 France
| | - Edith Demettre-Verceil
- Plate-forme de Protéomique Fonctionnelle - FPP; UMS CNRS 3426 - US 009 INSERM - UMI - UMII, IGF; 141 rue de la Cardonille 34094 Montpellier Cedex 5 France
| | - David Boteller
- University Montpellier II; CNRS UMR 5235, University Montpellier I; Dynamique des Interactions Membranaires Normales et Pathologiques 34095 Montpellier Cedex 5 France
| | - Catherine Braun-Breton
- University Montpellier II; CNRS UMR 5235, University Montpellier I; Dynamique des Interactions Membranaires Normales et Pathologiques 34095 Montpellier Cedex 5 France
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66
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Njunge JM, Mandal P, Przyborski JM, Boshoff A, Pesce ER, Blatch GL. PFB0595w is a Plasmodium falciparum J protein that co-localizes with PfHsp70-1 and can stimulate its in vitro ATP hydrolysis activity. Int J Biochem Cell Biol 2015; 62:47-53. [PMID: 25701168 DOI: 10.1016/j.biocel.2015.02.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 02/05/2015] [Accepted: 02/10/2015] [Indexed: 12/01/2022]
Abstract
Heat shock proteins, many of which function as molecular chaperones, play important roles in the lifecycle and pathogenesis of the malaria parasite, Plasmodium falciparum. The P. falciparum heat shock protein 70 (PfHsp70) family of chaperones is potentially regulated by a large complement of J proteins that localize to various intracellular compartments including the infected erythrocyte cytosol. While PfHsp70-1 has been shown to be an abundant cytosolic chaperone, its regulation by J proteins is poorly understood. In this study, we characterized the J protein PFB0595w, a homologue of the well-studied yeast cytosolic J protein, Sis1. PFB0595w, similarly to PfHsp70-1, was localized to the parasite cytosol and its expression was upregulated by heat shock. Additionally, recombinant PFB0595w was shown to be dimeric and to stimulate the in vitro ATPase activity of PfHsp70-1. Overall, the expression, localization and biochemical data for PFB0595w suggest that it may function as a cochaperone of PfHsp70-1, and advances current knowledge on the chaperone machinery of the parasite.
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Affiliation(s)
- James M Njunge
- Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes, Rhodes University, Grahamstown 6140, South Africa
| | - Pradipta Mandal
- Parasitology, Philipps University Marburg, 35043 Marburg, Germany
| | | | - Aileen Boshoff
- Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes, Rhodes University, Grahamstown 6140, South Africa
| | - Eva-Rachele Pesce
- College of Health and Biomedicine, Victoria University, Melbourne 8001, VIC, Australia
| | - Gregory L Blatch
- Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes, Rhodes University, Grahamstown 6140, South Africa; College of Health and Biomedicine, Victoria University, Melbourne 8001, VIC, Australia.
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67
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Host erythrocyte environment influences the localization of exported protein 2, an essential component of the Plasmodium translocon. EUKARYOTIC CELL 2015; 14:371-84. [PMID: 25662767 DOI: 10.1128/ec.00228-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/28/2015] [Indexed: 11/20/2022]
Abstract
Malaria parasites replicating inside red blood cells (RBCs) export a large subset of proteins into the erythrocyte cytoplasm to facilitate parasite growth and survival. PTEX, the parasite-encoded translocon, mediates protein transport across the parasitophorous vacuolar membrane (PVM) in Plasmodium falciparum-infected erythrocytes. Proteins exported into the erythrocyte cytoplasm have been localized to membranous structures, such as Maurer's clefts, small vesicles, and a tubovesicular network. Comparable studies of protein trafficking in Plasmodium vivax-infected reticulocytes are limited. With Plasmodium yoelii-infected reticulocytes, we identified exported protein 2 (Exp2) in a proteomic screen of proteins putatively transported across the PVM. Immunofluorescence studies showed that P. yoelii Exp2 (PyExp2) was primarily localized to the PVM. Unexpectedly, PyExp2 was also associated with distinct, membrane-bound vesicles in the reticulocyte cytoplasm. This is in contrast to P. falciparum in mature RBCs, where P. falciparum Exp2 (PfExp2) is exclusively localized to the PVM. Two P. yoelii-exported proteins, PY04481 (encoded by a pyst-a gene) and PY06203 (PypAg-1), partially colocalized with these PyExp2-positive vesicles. Further analysis revealed that with P. yoelii, Plasmodium berghei, and P. falciparum, cytoplasmic Exp2-positive vesicles were primarily observed in CD71(+) reticulocytes versus mature RBCs. In transgenic P. yoelii 17X parasites, the association of hemagglutinin-tagged PyExp2 with the PVM and cytoplasmic vesicles was retained, but the pyexp2 gene was refractory to deletion. These data suggest that the localization of Exp2 in mouse and human RBCs can be influenced by the host cell environment. Exp2 may function at multiple points in the pathway by which parasites traffic proteins into and through the reticulocyte cytoplasm.
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68
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Spillman NJ, Beck JR, Goldberg DE. Protein export into malaria parasite-infected erythrocytes: mechanisms and functional consequences. Annu Rev Biochem 2015; 84:813-41. [PMID: 25621510 DOI: 10.1146/annurev-biochem-060614-034157] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phylum Apicomplexa comprises a large group of obligate intracellular parasites of high medical and veterinary importance. These organisms succeed intracellularly by effecting remarkable changes in a broad range of diverse host cells. The transformation of the host erythrocyte is particularly striking in the case of the malaria parasite Plasmodium falciparum. P. falciparum exports hundreds of proteins that mediate a complex cellular renovation marked by changes in the permeability, rigidity, and cytoadherence properties of the host erythrocyte. The past decade has seen enormous progress in understanding the identity and function of these exported effectors, as well as the mechanisms by which they are trafficked into the host cell. Here we review these advances, place them in the context of host manipulation by related apicomplexans, and propose key directions for future research.
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69
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Pesce ER, Blatch GL, Edkins AL. Hsp40 Co-chaperones as Drug Targets: Towards the Development of Specific Inhibitors. TOPICS IN MEDICINAL CHEMISTRY 2015. [DOI: 10.1007/7355_2015_92] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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70
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Export of virulence proteins by malaria-infected erythrocytes involves remodeling of host actin cytoskeleton. Blood 2014; 124:3459-68. [PMID: 25139348 DOI: 10.1182/blood-2014-06-583054] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Following invasion of human red blood cells (RBCs) by the malaria parasite, Plasmodium falciparum, a remarkable process of remodeling occurs in the host cell mediated by trafficking of several hundred effector proteins to the RBC compartment. The exported virulence protein, P falciparum erythrocyte membrane protein 1 (PfEMP1), is responsible for cytoadherence of infected cells to host endothelial receptors. Maurer clefts are organelles essential for protein trafficking, sorting, and assembly of protein complexes. Here we demonstrate that disruption of PfEMP1 trafficking protein 1 (PfPTP1) function leads to severe alterations in the architecture of Maurer's clefts. Furthermore, 2 major surface antigen families, PfEMP1 and STEVOR, are no longer displayed on the host cell surface leading to ablation of cytoadherence to host receptors. PfPTP1 functions in a large complex of proteins and is required for linking of Maurer's clefts to the host actin cytoskeleton.
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71
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Dietz O, Rusch S, Brand F, Mundwiler-Pachlatko E, Gaida A, Voss T, Beck HP. Characterization of the small exported Plasmodium falciparum membrane protein SEMP1. PLoS One 2014; 9:e103272. [PMID: 25062022 PMCID: PMC4111544 DOI: 10.1371/journal.pone.0103272] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 06/26/2014] [Indexed: 12/03/2022] Open
Abstract
Survival and virulence of the human malaria parasite Plasmodium falciparum during the blood stage of infection critically depend on extensive host cell refurbishments mediated through export of numerous parasite proteins into the host cell. The parasite-derived membranous structures called Maurer's clefts (MC) play an important role in protein trafficking from the parasite to the red blood cell membrane. However, their specific function has yet to be determined. We identified and characterized a new MC membrane protein, termed small exported membrane protein 1 (SEMP1). Upon invasion it is exported into the RBC cytosol where it inserts into the MCs before it is partly translocated to the RBC membrane. Using conventional and conditional loss-of-function approaches we showed that SEMP1 is not essential for parasite survival, gametocytogenesis, or PfEMP1 export under culture conditions. Co-IP experiments identified several potential interaction partners, including REX1 and other membrane-associated proteins that were confirmed to co-localize with SEMP1 at MCs. Transcriptome analysis further showed that expression of a number of exported parasite proteins was up-regulated in SEMP1-depleted parasites. By using Co-IP and transcriptome analysis for functional characterization of an exported parasite protein we provide a new starting point for further detailed dissection and characterisation of MC-associated protein complexes.
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Affiliation(s)
- Olivier Dietz
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sebastian Rusch
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Françoise Brand
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Esther Mundwiler-Pachlatko
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Annette Gaida
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Till Voss
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Hans-Peter Beck
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
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72
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Beck JR, Muralidharan V, Oksman A, Goldberg DE. PTEX component HSP101 mediates export of diverse malaria effectors into host erythrocytes. Nature 2014; 511:592-5. [PMID: 25043010 PMCID: PMC4130291 DOI: 10.1038/nature13574] [Citation(s) in RCA: 197] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 06/11/2014] [Indexed: 12/02/2022]
Affiliation(s)
- Josh R Beck
- 1] Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri 63110, USA [2]
| | - Vasant Muralidharan
- 1] Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA [2] Howard Hughes Medical Institute, Washington University School of Medicine, St Louis, Missouri 63110, USA [3] [4] Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Anna Oksman
- 1] Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri 63110, USA [2] Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA [3] Howard Hughes Medical Institute, Washington University School of Medicine, St Louis, Missouri 63110, USA
| | - Daniel E Goldberg
- 1] Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri 63110, USA [2] Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA [3] Howard Hughes Medical Institute, Washington University School of Medicine, St Louis, Missouri 63110, USA
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73
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Proellocks NI, Herrmann S, Buckingham DW, Hanssen E, Hodges EK, Elsworth B, Morahan BJ, Coppel RL, Cooke BM. A lysine-rich membrane-associated PHISTb protein involved in alteration of the cytoadhesive properties of Plasmodium falciparum-infected red blood cells. FASEB J 2014; 28:3103-13. [PMID: 24706359 DOI: 10.1096/fj.14-250399] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The genomes of malaria parasites (Plasmodium spp.) contain a family of genes encoding proteins with a Plasmodium helical interspersed subtelomeric (PHIST) domain, most of which are predicted to be exported into the parasite-infected human red blood cell (iRBC). Here, using transgenic parasites and a combination of cellular, biochemical, and biophysical assays, we have characterized and determined the function of a novel member of the PHIST protein family in Plasmodium falciparum, termed lysine-rich membrane-associated PHISTb (LyMP). LyMP was shown to associate directly with the cytoskeleton of iRBCs where it plays a role in their abnormal ability to adhere to a protein expressed on vascular endothelial cells, resulting in sequestration. Deletion of LyMP dramatically reduced adhesion of iRBCs to CD36 by 55%, which was completely restored to wild-type levels on complementation. Intriguingly, in the absence of LyMP, formation of RBC membrane knobs and the level of surface exposure of the parasites' major cytoadhesive ligand, PfEMP1, were identical to those for the parental parasite line, demonstrating for the first time an additional mechanism that enhances cytoadherence of iRBCs beyond those already recognized. Our findings identify LyMP as a previously unknown RBC cytoskeletal-binding protein that is likely to be of major significance in the complex pathophysiology of falciparum malaria.-Proellocks, N. I., Herrmann, S., Buckingham, D. W., Hanssen, E., Hodges, E. K., Elsworth, B., Morahan, B. J., Coppel, R. L., Cooke, B. M. A lysine-rich membrane-associated PHISTb protein involved in alteration of the cytoadhesive properties of Plasmodium falciparum infected red blood cells.
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Affiliation(s)
| | - Susann Herrmann
- Department of Microbiology, Monash University, Victoria, Australia; and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia
| | | | - Eric Hanssen
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia
| | - Emma K Hodges
- Department of Microbiology, Monash University, Victoria, Australia; and
| | - Brendan Elsworth
- Department of Microbiology, Monash University, Victoria, Australia; and
| | - Belinda J Morahan
- Department of Microbiology, Monash University, Victoria, Australia; and
| | - Ross L Coppel
- Department of Microbiology, Monash University, Victoria, Australia; and
| | - Brian M Cooke
- Department of Microbiology, Monash University, Victoria, Australia; and
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74
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Kats LM, Fernandez KM, Glenister FK, Herrmann S, Buckingham DW, Siddiqui G, Sharma L, Bamert R, Lucet I, Guillotte M, Mercereau-Puijalon O, Cooke BM. An exported kinase (FIKK4.2) that mediates virulence-associated changes in Plasmodium falciparum-infected red blood cells. Int J Parasitol 2014; 44:319-28. [DOI: 10.1016/j.ijpara.2014.01.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 01/22/2014] [Accepted: 01/22/2014] [Indexed: 11/28/2022]
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75
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Abstract
SUMMARYPlasmodium falciparumdisplays a large and remarkable variety of heat shock protein 40 family members (PfHsp40s). The majority of the PfHsp40s are poorly characterized, and although the functions of some of them have been suggested, their exact mechanism of action is still elusive and their interacting partners and client proteins are unknown. TheP. falciparumheat shock protein 70 family members (PfHsp70s) have been more extensively characterized than the PfHsp40s, with certain members shown to function as molecular chaperones. However, little is known about the PfHsp70-PfHsp40 chaperone partnerships. There is mounting evidence that these chaperones are important not only in protein homoeostasis and cytoprotection, but also in protein trafficking across the parasitophorous vacuole (PV) and into the infected erythrocyte. We propose that certain members of these chaperone families work together to maintain exported proteins in an unfolded state until they reach their final destination. In this review, we critically evaluate what is known and not known about PfHsp40s and PfHsp70s.
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76
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Elsworth B, Crabb BS, Gilson PR. Protein export in malaria parasites: an update. Cell Microbiol 2014; 16:355-63. [PMID: 24418476 DOI: 10.1111/cmi.12261] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 01/04/2014] [Accepted: 01/06/2014] [Indexed: 11/30/2022]
Abstract
Symptomatic malaria is caused by the infection of human red blood cells (RBCs) with Plasmodium parasites. The RBC is a peculiar environment for parasites to thrive in as they lack many of the normal cellular processes and resources present in other cells. Because of this, Plasmodium spp. have adapted to extensively remodel the host cell through the export of hundreds of proteins that have a range of functions, the best known of which are virulence-associated. Many exported parasite proteins are themselves involved in generating a novel trafficking system in the RBC that further promotes export. In this review we provide an overview of the parasite synthesized export machinery as well as recent developments in how different classes of exported proteins are recognized by this machinery.
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Affiliation(s)
- Brendan Elsworth
- Burnet Institute, 85 Commercial Road, Melbourne, Vic., 3004, Australia; Monash University, Clayton, Vic., Australia
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77
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Abstract
Plasmodium falciparum, the causative agent of malaria, completely remodels the infected human erythrocyte to acquire nutrients and to evade the immune system. For this process, the parasite exports more than 10% of all its proteins into the host cell cytosol, including the major virulence factor PfEMP1 (P. falciparum erythrocyte surface protein 1). This unusual protein trafficking system involves long-known parasite-derived membranous structures in the host cell cytosol, called Maurer's clefts. However, the genesis, role, and function of Maurer's clefts remain elusive. Similarly unclear is how proteins are sorted and how they are transported to and from these structures. Recent years have seen a large increase of knowledge but, as yet, no functional model has been established. In this perspective we review the most important findings and conclude with potential possibilities to shed light into the enigma of Maurer's clefts. Understanding the mechanism and function of these structures, as well as their involvement in protein export in P. falciparum, might lead to innovative control strategies and might give us a handle with which to help to eliminate this deadly parasite.
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78
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van Ooij C, Withers-Martinez C, Ringel A, Cockcroft S, Haldar K, Blackman MJ. Identification of a Plasmodium falciparum phospholipid transfer protein. J Biol Chem 2013; 288:31971-83. [PMID: 24043620 PMCID: PMC3814793 DOI: 10.1074/jbc.m113.474189] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Infection of erythrocytes by the human malaria parasite Plasmodium falciparum results in dramatic modifications to the host cell, including changes to its antigenic and transport properties and the de novo formation of membranous compartments within the erythrocyte cytosol. These parasite-induced structures are implicated in the transport of nutrients, metabolic products, and parasite proteins, as well as in parasite virulence. However, very few of the parasite effector proteins that underlie remodeling of the host erythrocyte are functionally characterized. Using bioinformatic examination and modeling, we have found that the exported P. falciparum protein PFA0210c belongs to the START domain family, members of which mediate transfer of phospholipids, ceramide, or fatty acids between membranes. In vitro phospholipid transfer assays using recombinant PFA0210 confirmed that it can transfer phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine, and sphingomyelin between phospholipid vesicles. Furthermore, assays using HL60 cells containing radiolabeled phospholipids indicated that orthologs of PFA0210c can also transfer phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine. Biochemical and immunochemical analysis showed that PFA0210c associates with membranes in infected erythrocytes at mature stages of intracellular parasite growth. Localization studies in live parasites revealed that the protein is present in the parasitophorous vacuole during growth and is later recruited to organelles in the parasite. Together these data suggest that PFA0210c plays a role in the formation of the membranous structures and nutrient phospholipid transfer in the malaria-parasitized erythrocyte.
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Affiliation(s)
- Christiaan van Ooij
- From the Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, United Kingdom
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79
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Hatherley R, Blatch GL, Bishop ÖT. Plasmodium falciparumHsp70-x: a heat shock protein at the host–parasite interface. J Biomol Struct Dyn 2013; 32:1766-79. [DOI: 10.1080/07391102.2013.834849] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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80
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Boddey JA, Cowman AF. PlasmodiumNesting: Remaking the Erythrocyte from the Inside Out. Annu Rev Microbiol 2013; 67:243-69. [DOI: 10.1146/annurev-micro-092412-155730] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Justin A. Boddey
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; ,
| | - Alan F. Cowman
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; ,
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81
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Marti M, Spielmann T. Protein export in malaria parasites: many membranes to cross. Curr Opin Microbiol 2013; 16:445-51. [PMID: 23725671 DOI: 10.1016/j.mib.2013.04.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 04/24/2013] [Accepted: 04/30/2013] [Indexed: 11/19/2022]
Abstract
The continuous multiplication of Plasmodium parasites in red blood cells leads to a rapid increase in parasite numbers and is responsible for the disease symptoms of malaria. Survival and virulence of the parasite are linked to parasite-induced changes of the host red blood cells. These alterations require export of a large number of parasite proteins that are trafficked across multiple membranes to reach the host cell. Two classes of exported proteins are known, those with a conserved Plasmodium export element (PEXEL/HT) or those without this motif (PNEPs). Recent work has revealed new aspects of the determinants required for export of these 2 protein classes, shedding new light on the mode of trafficking during the different transport steps en route to the host cell.
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Affiliation(s)
- Matthias Marti
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA
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82
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Regev-Rudzki N, Wilson DW, Carvalho TG, Sisquella X, Coleman BM, Rug M, Bursac D, Angrisano F, Gee M, Hill AF, Baum J, Cowman AF. Cell-cell communication between malaria-infected red blood cells via exosome-like vesicles. Cell 2013; 153:1120-33. [PMID: 23683579 DOI: 10.1016/j.cell.2013.04.029] [Citation(s) in RCA: 417] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 03/12/2013] [Accepted: 04/16/2013] [Indexed: 12/27/2022]
Abstract
Cell-cell communication is an important mechanism for information exchange promoting cell survival for the control of features such as population density and differentiation. We determined that Plasmodium falciparum-infected red blood cells directly communicate between parasites within a population using exosome-like vesicles that are capable of delivering genes. Importantly, communication via exosome-like vesicles promotes differentiation to sexual forms at a rate that suggests that signaling is involved. Furthermore, we have identified a P. falciparum protein, PfPTP2, that plays a key role in efficient communication. This study reveals a previously unidentified pathway of P. falciparum biology critical for survival in the host and transmission to mosquitoes. This identifies a pathway for the development of agents to block parasite transmission from the human host to the mosquito.
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Affiliation(s)
- Neta Regev-Rudzki
- Division of Infection and Immunity, the Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
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83
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The exported protein PbCP1 localises to cleft-like structures in the rodent malaria parasite Plasmodium berghei. PLoS One 2013; 8:e61482. [PMID: 23658610 PMCID: PMC3637216 DOI: 10.1371/journal.pone.0061482] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 03/11/2013] [Indexed: 02/02/2023] Open
Abstract
Protein export into the host red blood cell is one of the key processes in the pathobiology of the malaria parasite Plasmodiumtrl falciparum, which extensively remodels the red blood cell to ensure its virulence and survival. In this study, we aimed to shed further light on the protein export mechanisms in the rodent malaria parasite P. berghei and provide further proof of the conserved nature of host cell remodeling in Plasmodium spp. Based on the presence of an export motif (R/KxLxE/Q/D) termed PEXEL (Plasmodium export element), we have generated transgenic P. berghei parasite lines expressing GFP chimera of putatively exported proteins and analysed one of the newly identified exported proteins in detail. This essential protein, termed PbCP1 (P. berghei Cleft-like Protein 1), harbours an atypical PEXEL motif (RxLxY) and is further characterised by two predicted transmembrane domains (2TMD) in the C-terminal end of the protein. We have functionally validated the unusual PEXEL motif in PbCP1 and analysed the role of the 2TMD region, which is required to recruit PbCP1 to discrete membranous structures in the red blood cell cytosol that have a convoluted, vesico-tubular morphology by electron microscopy. Importantly, this study reveals that rodent malaria species also induce modifications to their host red blood cell.
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84
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McMillan PJ, Millet C, Batinovic S, Maiorca M, Hanssen E, Kenny S, Muhle RA, Melcher M, Fidock DA, Smith JD, Dixon MWA, Tilley L. Spatial and temporal mapping of the PfEMP1 export pathway in Plasmodium falciparum. Cell Microbiol 2013; 15:1401-18. [PMID: 23421990 DOI: 10.1111/cmi.12125] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 02/01/2013] [Accepted: 02/07/2013] [Indexed: 01/24/2023]
Abstract
The human malaria parasite, Plasmodium falciparum, modifies the red blood cells (RBCs) that it infects by exporting proteins to the host cell. One key virulence protein, P. falciparum Erythrocyte Membrane Protein-1 (PfEMP1), is trafficked to the surface of the infected RBC, where it mediates adhesion to the vascular endothelium. We have investigated the organization and development of the exomembrane system that is used for PfEMP1 trafficking. Maurer's cleft cisternae are formed early after invasion and proteins are delivered to these (initially mobile) structures in a temporally staggered and spatially segregated manner. Membrane-Associated Histidine-Rich Protein-2 (MAHRP2)-containing tether-like structures are generated as early as 4 h post invasion and become attached to Maurer's clefts. The tether/Maurer's cleft complex docks onto the RBC membrane at ~20 h post invasion via a process that is not affected by cytochalasin D treatment. We have examined the trafficking of a GFP chimera of PfEMP1 expressed in transfected parasites. PfEMP1B-GFP accumulates near the parasite surface, within membranous structures exhibiting a defined ultrastructure, before being transferred to pre-formed mobile Maurer's clefts. Endogenous PfEMP1 and PfEMP1B-GFP are associated with Electron-Dense Vesicles that may be responsible for trafficking PfEMP1 from the Maurer's clefts to the RBC membrane.
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Affiliation(s)
- Paul J McMillan
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Victoria, Australia
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85
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Gohil S, Kats LM, Seemann T, Fernandez KM, Siddiqui G, Cooke BM. Bioinformatic prediction of the exportome of Babesia bovis and identification of novel proteins in parasite-infected red blood cells. Int J Parasitol 2013; 43:409-16. [PMID: 23395698 DOI: 10.1016/j.ijpara.2013.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/15/2013] [Accepted: 01/16/2013] [Indexed: 10/27/2022]
Abstract
Babesia bovis is a pathogen of considerable economic significance to the livestock industry worldwide but the precise mechanisms by which this parasite causes disease in susceptible cattle remain poorly understood. It is clear, however, that alterations to the structure and function of red blood cells in which the parasites reside and replicate play an important role in pathogenesis and that these are secondary to the export of numerous, currently unknown and uncharacterised parasite-encoded proteins. Using a rational bioinformatic approach, we have identified a set of 362 proteins (117 of which are hypothetical) that we predict encompasses the B. bovis exportome. These exported proteins are likely to be trafficked to various cellular locations, with a subset destined for the red blood cell cytosol or the red blood cell cytoskeleton. These proteins are likely to play important roles in mediating the pathogenesis of babesiosis. We have selected three novel proteins and confirmed their predicted export and localisation within the host red blood cell by immunofluorescence using specific antibodies raised against these proteins. Complete characterisation of these novel exported parasite proteins will help elucidate their function within the host red blood cell and assist in identification of new therapeutic targets for babesiosis.
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Affiliation(s)
- Sejal Gohil
- Department of Microbiology, Monash University, Victoria 3800, Australia
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86
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Grover M, Chaubey S, Ranade S, Tatu U. Identification of an exported heat shock protein 70 in Plasmodium falciparum. ACTA ACUST UNITED AC 2013; 20:2. [PMID: 23340228 PMCID: PMC3718529 DOI: 10.1051/parasite/2012002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 10/26/2012] [Indexed: 11/15/2022]
Abstract
Host cell remodelling is a hallmark of malaria pathogenesis. It involves protein folding, unfolding and trafficking events and thus participation of chaperones such as Hsp70s and Hsp40s is well speculated. Until recently, only Hsp40s were thought to be the sole representative of the parasite chaperones in the exportome. However, based on the re-annotated Plasmodium falciparum genome sequence, a putative candidate for exported Hsp70 has been reported, which otherwise was known to be a pseudogene. We raised a specific antiserum against a C-terminal peptide uniquely present in PfHsp70-x. Immunoblotting and immunofluorescence-based approaches in combination with sub-cellular fractionation by saponin and streptolysin-O have been taken to determine the expression and localization of PfHsp70-x in infected erythrocyte. The re-annotated sequence of PfHsp70-x reveals it to be a functional protein with an endoplasmic reticulum signal peptide. It gets maximally expressed at the schizont stage of intra-erythrocytic life cycle. Majority of the protein localizes to the parasitophorous vacuole and some of it gets exported to the erythrocyte compartment where it associates with Maurer's clefts. The identification of an exported parasite Hsp70 chaperone presents us with the fact that the parasite has evolved customized chaperones which might be playing crucial roles in aspects of trafficking and host cell remodelling.
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87
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Külzer S, Petersen W, Baser A, Mandel K, Przyborski JM. Use of self-assembling GFP to determine protein topology and compartmentalisation in the Plasmodium falciparum-infected erythrocyte. Mol Biochem Parasitol 2012; 187:87-90. [PMID: 23271009 DOI: 10.1016/j.molbiopara.2012.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Revised: 11/12/2012] [Accepted: 11/21/2012] [Indexed: 11/18/2022]
Abstract
In recent years, and largely supported by the increasing use of transfection technology, much research attention has been given to protein trafficking in the Plasmodium falciparum infected red blood cell. By expression of fluorescent reporter proteins, much information has been gained on both the signals and mechanisms directing proteins to their correct sub-cellular localisation within the parasite and infected host cell. Generally however, verification of the observed fluorescent phenotype is carried out using more traditional techniques such as co-immunofluorescence, protease protection, and cell fractionation followed by Western blot. Here we apply a self-assembling split GFP (saGFP) system and show that this can be used to determine both membrane topology and compartmentalisation using transfection technology alone. As an example, we verify the topology of an ER membrane protein, hDer1-1, and of an exported parasite Hsp40 co-chaperone, PFE55. Additionally, we can demonstrate that this system has the potential to be applied to analysis of organellar proteins.
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Affiliation(s)
- Simone Külzer
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
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88
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Bullen HE, Crabb BS, Gilson PR. Recent insights into the export of PEXEL/HTS-motif containing proteins in Plasmodium parasites. Curr Opin Microbiol 2012; 15:699-704. [DOI: 10.1016/j.mib.2012.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 09/22/2012] [Accepted: 09/25/2012] [Indexed: 10/27/2022]
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89
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Deponte M, Hoppe HC, Lee MC, Maier AG, Richard D, Rug M, Spielmann T, Przyborski JM. Wherever I may roam: Protein and membrane trafficking in P. falciparum-infected red blood cells. Mol Biochem Parasitol 2012; 186:95-116. [DOI: 10.1016/j.molbiopara.2012.09.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/21/2012] [Accepted: 09/24/2012] [Indexed: 11/27/2022]
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90
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Pasini EM, Braks JA, Fonager J, Klop O, Aime E, Spaccapelo R, Otto TD, Berriman M, Hiss JA, Thomas AW, Mann M, Janse CJ, Kocken CHM, Franke-Fayard B. Proteomic and genetic analyses demonstrate that Plasmodium berghei blood stages export a large and diverse repertoire of proteins. Mol Cell Proteomics 2012. [PMID: 23197789 PMCID: PMC3567864 DOI: 10.1074/mcp.m112.021238] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Malaria parasites actively remodel the infected red blood cell (irbc) by exporting proteins into the host cell cytoplasm. The human parasite Plasmodium falciparum exports particularly large numbers of proteins, including proteins that establish a vesicular network allowing the trafficking of proteins onto the surface of irbcs that are responsible for tissue sequestration. Like P. falciparum, the rodent parasite P. berghei ANKA sequesters via irbc interactions with the host receptor CD36. We have applied proteomic, genomic, and reverse-genetic approaches to identify P. berghei proteins potentially involved in the transport of proteins to the irbc surface. A comparative proteomics analysis of P. berghei non-sequestering and sequestering parasites was used to determine changes in the irbc membrane associated with sequestration. Subsequent tagging experiments identified 13 proteins (Plasmodium export element (PEXEL)-positive as well as PEXEL-negative) that are exported into the irbc cytoplasm and have distinct localization patterns: a dispersed and/or patchy distribution, a punctate vesicle-like pattern in the cytoplasm, or a distinct location at the irbc membrane. Members of the PEXEL-negative BIR and PEXEL-positive Pb-fam-3 show a dispersed localization in the irbc cytoplasm, but not at the irbc surface. Two of the identified exported proteins are transported to the irbc membrane and were named erythrocyte membrane associated proteins. EMAP1 is a member of the PEXEL-negative Pb-fam-1 family, and EMAP2 is a PEXEL-positive protein encoded by a single copy gene; neither protein plays a direct role in sequestration. Our observations clearly indicate that P. berghei traffics a diverse range of proteins to different cellular locations via mechanisms that are analogous to those employed by P. falciparum. This information can be exploited to generate transgenic humanized rodent P. berghei parasites expressing chimeric P. berghei/P. falciparum proteins on the surface of rodent irbc, thereby opening new avenues for in vivo screening adjunct therapies that block sequestration.
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Affiliation(s)
- Erica M Pasini
- Biomedical Primate Research Centre, 2288 GJ Rijswijk, The Netherlands
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91
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Nilsson S, Angeletti D, Wahlgren M, Chen Q, Moll K. Plasmodium falciparum antigen 332 is a resident peripheral membrane protein of Maurer's clefts. PLoS One 2012. [PMID: 23185236 PMCID: PMC3502387 DOI: 10.1371/journal.pone.0046980] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During the intraerythrocytic development of Plasmodium falciparum, the malaria parasite remodels the host cell cytosol by inducing membranous structures termed Maurer's clefts and inserting parasite proteins into the red blood cell cytoskeleton and plasma membrane. Pf332 is the largest known asexual malaria antigen that is exported into the red blood cell cytosol where it associates with Maurer's clefts. In the current work, we have utilized a set of different biochemical assays to analyze the solubility of the endogenous Pf332 molecule during its trafficking from the endoplasmic reticulum within the parasite to the host cell cytosol. Solubilization studies demonstrate that Pf332 is synthesized and trafficked within the parasite as a peripheral membrane protein, which after export into the host cell cytosol associates with the cytoplasmic side of Maurer's clefts in a peripheral manner. By immunofluorescence microscopy and flow cytometry, we show that Pf332 persists in close association with Maurer's clefts throughout trophozoite maturation and schizogony, and does not become exposed at the host cell surface. Our data also indicate that Pf332 interacts with the host cell cytoskeleton, but only in very mature parasite stages. Thus, the present study describes Pf332 as a resident peripheral membrane protein of Maurer's clefts and suggests that the antigen participates in host cytoskeleton modifications at completion of the intraerythrocytic developmental cycle.
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Affiliation(s)
- Sandra Nilsson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- * E-mail: (SN); (KM)
| | - Davide Angeletti
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Mats Wahlgren
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Qijun Chen
- Laboratory of Parasitology, Institute of Pathogen Biology, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Kirsten Moll
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- * E-mail: (SN); (KM)
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92
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Uncovering Common Principles in Protein Export of Malaria Parasites. Cell Host Microbe 2012; 12:717-29. [DOI: 10.1016/j.chom.2012.09.010] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 08/16/2012] [Accepted: 09/04/2012] [Indexed: 11/21/2022]
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93
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An exported heat shock protein 40 associates with pathogenesis-related knobs in Plasmodium falciparum infected erythrocytes. PLoS One 2012; 7:e44605. [PMID: 22970262 PMCID: PMC3436795 DOI: 10.1371/journal.pone.0044605] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 08/03/2012] [Indexed: 11/19/2022] Open
Abstract
Cell surface structures termed knobs are one of the most important pathogenesis related protein complexes deployed by the malaria parasite Plasmodium falciparum at the surface of the infected erythrocyte. Despite their relevance to the disease, their structure, mechanisms of traffic and their process of assembly remain poorly understood. In this study, we have explored the possible role of a parasite-encoded Hsp40 class of chaperone, namely PFB0090c/PF3D7_0201800 (KAHsp40) in protein trafficking in the infected erythrocyte. We found the gene coding for PF3D7_0201800 to be located in a chromosomal cluster together with knob components KAHRP and PfEMP3. Like the knob components, KAHsp40 too showed the presence of PEXEL motif required for transport to the erythrocyte compartment. Indeed, sub-cellular fractionation and immunofluorescence analysis (IFA) showed KAHsp40 to be exported in the erythrocyte cytoplasm in a stage dependent manner localizing as punctuate spots in the erythrocyte periphery, distinctly from Maurer’s cleft, in structures which could be the reminiscent of knobs. Double IFA analysis revealed co-localization of PF3D7_0201800 with the markers of knobs (KAHRP, PfEMP1 and PfEMP3) and components of the PEXEL translocon (Hsp101, PTEX150). KAHsp40 was also found to be in a complex with KAHRP, PfEMP3 and Hsp101 as confirmed by co-immunoprecipitation assay. Our results suggest potential involvement of a parasite encoded Hsp40 in chaperoning knob assembly in the erythrocyte compartment.
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94
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Külzer S, Charnaud S, Dagan T, Riedel J, Mandal P, Pesce ER, Blatch GL, Crabb BS, Gilson PR, Przyborski JM. Plasmodium falciparum-encoded exported hsp70/hsp40 chaperone/co-chaperone complexes within the host erythrocyte. Cell Microbiol 2012; 14:1784-95. [PMID: 22925632 DOI: 10.1111/j.1462-5822.2012.01840.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 07/17/2012] [Accepted: 07/17/2012] [Indexed: 01/20/2023]
Abstract
Malaria parasites modify their host cell, the mature human erythrocyte. We are interested in the molecules mediating these processes, and have recently described a family of parasite-encoded heat shock proteins (PfHsp40s) that are targeted to the host cell, and implicated in host cell modification. Hsp40s generally function as co-chaperones of members of the Hsp70 family, and until now it was thought that human Hsp70 acts as the PfHsp40 interaction partner within the host cell. Here we revise this hypothesis, and identify and characterize an exported parasite-encoded Hsp70, referred to as PfHsp70-x. PfHsp70-x is exported to the host erythrocyte where it forms a complex with PfHsp40s in structures known as J-dots, and is closely associated with PfEMP1. Interestingly, Hsp70-x is encoded only by parasite species that export the major virulence factor EMP1, implying a possible role for Hsp70-x in EMP1 presentation at the surface of the infected erythrocyte. Our data strongly support the presence of parasite-encoded chaperone/co-chaperone complexes within the host erythrocyte, which are involved in protein traffic through the host cell. The host-pathogen interaction within the infected erythrocyte is more complex than previously thought, and is driven notonly by parasite co-chaperones, but also by the parasite-encoded chaperone Hsp70-x itself.
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Affiliation(s)
- Simone Külzer
- Parasitology, Philipps University Marburg, Marburg, Germany
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95
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Ingmundson A, Nahar C, Brinkmann V, Lehmann MJ, Matuschewski K. The exported Plasmodium berghei protein IBIS1 delineates membranous structures in infected red blood cells. Mol Microbiol 2012; 83:1229-43. [PMID: 22329949 PMCID: PMC3502748 DOI: 10.1111/j.1365-2958.2012.08004.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2012] [Indexed: 12/01/2022]
Abstract
The importance of pathogen-induced host cell remodelling has been well established for red blood cell infection by the human malaria parasite Plasmodium falciparum. Exported parasite-encoded proteins, which often possess a signature motif, termed Plasmodium export element (PEXEL) or host-targeting (HT) signal, are critical for the extensive red blood cell modifications. To what extent remodelling of erythrocyte membranes also occurs in non-primate hosts and whether it is in fact a hallmark of all mammalian Plasmodium parasites remains elusive. Here we characterize a novel Plasmodium berghei PEXEL/HT-containing protein, which we term IBIS1. Temporal expression and spatial localization determined by fluorescent tagging revealed the presence of IBIS1 at the parasite/host interface during both liver and blood stages of infection. Targeted deletion of the IBIS1 protein revealed a mild impairment of intra-erythrocytic growth indicating a role for these structures in the rapid expansion of the parasite population in the blood in vivo. In red blood cells, the protein localizes to dynamic, punctate structures external to the parasite. Biochemical and microscopic data revealed that these intra-erythrocytic P. berghei-induced structures (IBIS) are membranous indicating that P. berghei, like P. falciparum, creates an intracellular membranous network in infected red blood cells.
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Affiliation(s)
- Alyssa Ingmundson
- Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany.
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96
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Mbengue A, Yam XY, Braun-Breton C. Human erythrocyte remodelling during Plasmodium falciparum malaria parasite growth and egress. Br J Haematol 2012; 157:171-9. [PMID: 22313394 DOI: 10.1111/j.1365-2141.2012.09044.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The intra-erythrocyte growth and survival of the malarial parasite Plasmodium falciparum is responsible for both uncomplicated and severe malaria cases and depends on the parasite's ability to remodel its host cell. Host cell remodelling has several functions for the parasite, such as acquiring nutrients from the extracellular milieu because of the loss of membrane transporters upon erythrocyte differentiation, avoiding splenic clearance by conferring cytoadhesive properties to the infected erythrocyte, escaping the host immune response by exporting antigenically variant proteins at the red blood cell surface. In addition, parasite-induced changes at the red blood cell membrane and sub-membrane skeleton are also necessary for the efficient release of the parasite progeny from the host cell. Here we review these cellular and molecular changes, which might not only sustain parasite growth but also prepare, at a very early stage, the last step of egress from the host cell.
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Affiliation(s)
- Alassane Mbengue
- CNRS UMR 5235, University Montpellier II, Dynamique des Interactions Membranaires Normales et Pathologiques, Montpellier, France
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97
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Bernabeu M, Lopez FJ, Ferrer M, Martin-Jaular L, Razaname A, Corradin G, Maier AG, Del Portillo HA, Fernandez-Becerra C. Functional analysis of Plasmodium vivax VIR proteins reveals different subcellular localizations and cytoadherence to the ICAM-1 endothelial receptor. Cell Microbiol 2011; 14:386-400. [PMID: 22103402 DOI: 10.1111/j.1462-5822.2011.01726.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The subcellular localization and function of variant subtelomeric multigene families in Plasmodium vivax remain vastly unknown. Among them, the vir superfamily is putatively involved in antigenic variation and in mediating adherence to endothelial receptors. In the absence of a continuous in vitro culture system for P. vivax, we have generated P. falciparum transgenic lines expressing VIR proteins to infer location and function. We chose three proteins pertaining to subfamilies A (VIR17), C (VIR14) and D (VIR10), with domains and secondary structures that predictably traffic these proteins to different subcellular compartments. Here, we showed that VIR17 remained inside the parasite and around merozoites, whereas VIR14 and VIR10 were exported to the membrane of infected red blood cells (iRBCs) in an apparent independent pathway of Maurer's clefts. Remarkably, VIR14 was exposed at the surface of iRBCs and mediated adherence to different endothelial receptors expressed in CHO cells under static conditions. Under physiological flow conditions, however, cytoadherence was only observed to ICAM-1, which was the only receptor whose adherence was specifically and significantly inhibited by antibodies against conserved motifs of VIR proteins. Immunofluorescence studies using these antibodies also showed different subcellular localizations of VIR proteins in P. vivax-infected reticulocytes from natural infections. These data suggest that VIR proteins are trafficked to different cellular compartments and functionally demonstrates that VIR proteins can specifically mediate cytoadherence to the ICAM-1 endothelial receptor.
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Affiliation(s)
- M Bernabeu
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
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98
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Rug M, Maier AG. The heat shock protein 40 family of the malaria parasite Plasmodium falciparum. IUBMB Life 2011; 63:1081-6. [DOI: 10.1002/iub.525] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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99
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Botha M, Chiang AN, Needham PG, Stephens LL, Hoppe HC, Külzer S, Przyborski JM, Lingelbach K, Wipf P, Brodsky JL, Shonhai A, Blatch GL. Plasmodium falciparum encodes a single cytosolic type I Hsp40 that functionally interacts with Hsp70 and is upregulated by heat shock. Cell Stress Chaperones 2011; 16:389-401. [PMID: 21191678 PMCID: PMC3118825 DOI: 10.1007/s12192-010-0250-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 12/10/2010] [Accepted: 12/13/2010] [Indexed: 10/18/2022] Open
Abstract
Heat shock protein 70 (Hsp70) and heat shock protein 40 (Hsp40) function as molecular chaperones during the folding and trafficking of proteins within most cell types. However, the Hsp70-Hsp40 chaperone partnerships within the malaria parasite, Plasmodium falciparum, have not been elucidated. Only one of the 43 P. falciparum Hsp40s is predicted to be a cytosolic, canonical Hsp40 (termed PfHsp40) capable of interacting with the major cytosolic P. falciparum-encoded Hsp70, PfHsp70. Consistent with this hypothesis, we found that PfHsp40 is upregulated under heat shock conditions in a similar pattern to PfHsp70. In addition, PfHsp70 and PfHsp40 reside mainly in the parasite cytosol, as assessed using indirect immunofluorescence microscopy. Recombinant PfHsp40 stimulated the ATP hydrolytic rates of both PfHsp70 and human Hsp70 similar to other canonical Hsp40s of yeast (Ydj1) and human (Hdj2) origin. In contrast, the Hsp40-stimulated plasmodial and human Hsp70 ATPase activities were differentially inhibited in the presence of pyrimidinone-based small molecule modulators. To further probe the chaperone properties of PfHsp40, protein aggregation suppression assays were conducted. PfHsp40 alone suppressed protein aggregation, and cooperated with PfHsp70 to suppress aggregation. Together, these data represent the first cellular and biochemical evidence for a PfHsp70-PfHsp40 partnership in the malaria parasite, and furthermore that the plasmodial and human Hsp70-Hsp40 chaperones possess unique attributes that are differentially modulated by small molecules.
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Affiliation(s)
- Melissa Botha
- Biomedical Biotechnology Research Unit, Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown, South Africa
| | - Annette N. Chiang
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA USA
| | - Patrick G. Needham
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA USA
| | - Linda L. Stephens
- Biomedical Biotechnology Research Unit, Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown, South Africa
| | - Heinrich C. Hoppe
- Council for Scientific and Industrial Research, Pretoria, South Africa
| | - Simone Külzer
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
| | - Jude M. Przyborski
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
| | - Klaus Lingelbach
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA USA
| | - Jeffrey L. Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA USA
| | - Addmore Shonhai
- Department of Biochemistry and Microbiology, University of Zululand, Kwadlangezwa, South Africa
| | - Gregory L. Blatch
- Biomedical Biotechnology Research Unit, Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown, South Africa
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100
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P. falciparum modulates erythroblast cell gene expression in signaling and erythrocyte production pathways. PLoS One 2011; 6:e19307. [PMID: 21573240 PMCID: PMC3087761 DOI: 10.1371/journal.pone.0019307] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 03/28/2011] [Indexed: 01/18/2023] Open
Abstract
Global, genomic responses of erythrocytes to infectious agents have been difficult to measure because these cells are e-nucleated. We have previously demonstrated that in vitro matured, nucleated erythroblast cells at the orthochromatic stage can be efficiently infected by the human malaria parasite Plasmodium falciparum. We now show that infection of orthochromatic cells induces change in 609 host genes. 592 of these transcripts are up-regulated and associated with metabolic and chaperone pathways unique to P. falciparum infection, as well as a wide range of signaling pathways that are also induced in related apicomplexan infections of mouse hepatocytes or human fibroblast cells. Our data additionally show that polychromatophilic cells, which precede the orthochromatic stage and are not infected when co-cultured with P. falciparum, up-regulate a small set of genes, at least two of which are associated with pathways of hematopoiesis and/or erythroid cell development. These data support the idea that P. falciparum affects erythropoiesis at multiple stages during erythroblast differentiation. Further P. falciparum may modulate gene expression in bystander erythroblasts and thus influence pathways of erythrocyte development. This study provides a benchmark of the host erythroblast cell response to infection by P. falciparum.
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