Leupeptin alters the proteolytic processing of P126, the major parasitophorous vacuole antigen of Plasmodium falciparum

1989 ◽  
Vol 33 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Alain Debrabant ◽  
Patrick Delplace
Keyword(s):  
Plasmodium Falciparum ◽  
Parasitophorous Vacuole ◽  
Proteolytic Processing

Protein–protein interaction studies reveal the Plasmodium falciparum merozoite surface protein-1 region involved in a complex formation that binds to human erythrocytes

2018 ◽  
Vol 475 (6) ◽  
pp. 1197-1209 ◽  
Author(s):  
Gourab Paul ◽  
Arunaditya Deshmukh ◽  
Bishwanath Kumar Chourasia ◽  
Md Kalamuddin ◽  
Ashutosh Panda ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Recombinant Proteins ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Human Erythrocytes ◽  
Proteolytic Processing ◽  
Protein Protein Interaction ◽  
Falciparum Merozoite ◽  
Vaccine Candidate Antigen ◽  
Serological Studies

Plasmodium falciparum merozoite surface protein (PfMSP) 1 has been studied extensively as a vaccine candidate antigen. PfMSP-1 undergoes proteolytic processing into four major products, such as p83, p30, p38, and p42, that are associated in the form of non-covalent complex(s) with other MSPs. To delineate MSP1 regions involved in the interaction with other MSPs, here we expressed recombinant proteins (PfMSP-165) encompassing part of p38 and p42 regions and PfMSP-119. PfMSP-165 interacted strongly with PfMSP-3, PfMSP-6, PfMSP-7, and PfMSP-9, whereas PfMSP-119 did not interact with any of these proteins. Since MSP-1 complex binds human erythrocytes, we examined the ability of these proteins to bind human erythrocyte. Among the proteins of MSP-1 complex, PfMSP-6 and PfMSP-9 bound to human erythrocytes. Serological studies showed that PfMSP-165 was frequently recognized by sera from malaria endemic regions, whereas this was not the case for PfMSP-119. In contrast, antibodies against PfMSP-119 showed much higher inhibition of merozoite invasion compared with antibodies against the larger PfMSP-165 fragment. Importantly, anti-PfMSP-119 antibodies recognized both recombinant proteins, PfMSP-119 and PfMSP-165; however, anti-PfMSP-165 antibody failed to recognize the PfMSP-119 protein. Taken together, these results demonstrate that PfMSP-1 sequences upstream of the 19 kDa C-terminal region are involved in molecular interactions with other MSPs, and these sequences may probably serve as a smoke screen to evade antibody response to the membrane-bound C-terminal 19 kDa region.

scholarly journals Skeleton-binding protein 1 functions at the parasitophorous vacuole membrane to traffic PfEMP1 to the Plasmodium falciparum–infected erythrocyte surface

Blood ◽  
2006 ◽  
Vol 109 (3) ◽  
pp. 1289-1297 ◽  
Author(s):  
Alexander G. Maier ◽  
Melanie Rug ◽  
Matthew T. O'Neill ◽  
James G. Beeson ◽  
Matthias Marti ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Transport ◽  
Infected Erythrocyte ◽  
Binding Protein ◽  
Parasitophorous Vacuole ◽  
Surface Protein ◽  
Severe Form ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane ◽  
Erythrocyte Surface

Abstract A key feature of Plasmodium falciparum, the parasite causing the most severe form of malaria in humans, is its ability to export parasite molecules onto the surface of the erythrocyte. The major virulence factor and variant surface protein PfEMP1 (P falciparum erythrocyte membrane protein 1) acts as a ligand to adhere to endothelial receptors avoiding splenic clearance. Because the erythrocyte is devoid of protein transport machinery, the parasite provides infrastructure for trafficking across membranes it traverses. In this study, we show that the P falciparum skeleton-binding protein 1 (PfSBP1) is required for transport of PfEMP1 to the P falciparum–infected erythrocyte surface. We present evidence that PfSBP1 functions at the parasitophorous vacuole membrane to load PfEMP1 into Maurer clefts during formation of these structures. Furthermore, the major reactivity of antibodies from malaria-exposed multigravid women is directed toward PfEMP1 because this is abolished in the absence of PfSBP1.

Protein p126: a parasitophorous vacuole antigen associated with the release of Plasmodium falciparum merozoites

1988 ◽  
Vol 64 (2) ◽  
pp. 215-221 ◽  
Author(s):  
Patrick Delplace ◽  
Aruna Bhatia ◽  
Maryvonne Cagnard ◽  
Daniel Camus ◽  
Guy Colombet ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Parasitophorous Vacuole

scholarly journals A revised mechanism for how Plasmodium falciparum recruits and exports proteins into its erythrocytic host cell.

2021 ◽  
Author(s):  
Mikha Gabriela ◽  
Kathryn Matthews ◽  
Cas Boshoven ◽  
Betty Kouskousis ◽  
David Steer ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Host Cell ◽  
Parasitophorous Vacuole ◽  
Specific Interactions ◽  
Parasitophorous Vacuole Membrane ◽  
Conducting Channel ◽  
Trophozoite Stage ◽  
Vacuole Membrane ◽  
N Terminus ◽  
Exported Protein

Plasmodium falciparum exports ~10% of its proteome into its host erythrocyte to modify the host cell’s physiology. The Plasmodium export element (PEXEL) motif contained within the N-terminus of most exported proteins directs the trafficking of those proteins into the erythrocyte. To reach the host cell, the PEXEL motif of exported proteins are processed by the endoplasmic reticulum (ER) resident aspartyl protease plasmepsin V. Then, following secretion into the parasite-encasing parasitophorous vacuole, the mature exported protein must be unfolded and translocated across the parasitophorous vacuole membrane by the Plasmodium translocon of exported proteins (PTEX). PTEX is a protein-conducting channel consisting of the pore-forming protein EXP2, the protein unfoldase HSP101, and structural component PTEX150. The mechanism of how exported proteins are specifically trafficked from the parasite’s ER following PEXEL cleavage to PTEX complexes on the parasitophorous vacuole membrane is currently not understood. Here, we present evidence that EXP2 and PTEX150 form a stable subcomplex that facilitates HSP101 docking. We also demonstrate that HSP101 localises both within the parasitophorous vacuole and within the parasite’s ER throughout the ring and trophozoite stage of the parasite, coinciding with the timeframe of protein export. Interestingly, we found that HSP101 can form specific interactions with model PEXEL proteins in the parasite ER, irrespective of their PEXEL processing status. Collectively, our data suggest that HSP101 recognises and chaperones PEXEL proteins from the ER to the parasitophorous vacuole and given HSP101’s specificity for the EXP2-PTEX150 subcomplex, this provides a mechanism for how exported proteins are specifically targeted to PTEX for translocation into the erythrocyte.

scholarly journals Plasmodium falciparum protein Pfs16 is a target for transmission-blocking antimalarial drug development

2021 ◽  
Author(s):  
Sabrina Yahiya ◽  
Charlie N Saunders ◽  
Ursula Straschil ◽  
Oliver J Fischer ◽  
Ainoa Rueda-Zubiaurre ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Parasitophorous Vacuole ◽  
Male Gamete ◽  
Immunoblot Analysis ◽  
Transmission Blocking ◽  
Lead Compounds ◽  
Phenotypic Screen ◽  
Starting Point ◽  
Cellular Target ◽  
Affinity Labelling

Phenotypic cell-based screens are critical to the discovery of new antimalarial lead compounds. However, identification and validation of cellular targets of lead compounds is required following discovery in a phenotypic screen. We recently discovered a Plasmodium transmission-blocking N-((4-hydroxychroman-4-yl)methyl)-sulfonamide (N-4HCS) compound, DDD01035881, in a phenotypic screen. DDD01035881 and its potent derivatives have been shown to block Plasmodium male gamete formation (microgametogenesis) with nanomolar activity. Here, we synthesised a photoactivatable N-4HCS derivative, probe 2, to identify the N-4HCS cellular target. Using probe 2 in photo-affinity labelling coupled with mass spectrometry, we identified the 16 kDa Plasmodium falciparum parasitophorous vacuole membrane protein Pfs16 as the likely cellular target of the N-4HCS series. Further validating Pfs16 as the cellular target of the N-4HCS series, the Cellular Thermal Shift Assay (CETSA) confirmed DDD01035881 stabilised Pfs16 in lysate from activated mature gametocytes. Additionally, photo-affinity labelling combined with in-gel fluorescence and immunoblot analysis confirmed the N-4HCS series interacted with Pfs16. High-resolution, widefield fluorescence and electron microscopy of N-4HCS-inhibited parasites was found to result in a cell morphology entirely consistent with targeted gene disruption of Pfs16. Taken together, these data strongly implicate Pfs16 as the target of DDD01035881 and establish the N-4HCS scaffold family as a powerful starting point from which future transmission-blocking antimalarials can be developed.

scholarly journals Origins of the parasitophorous vacuole membrane of the malaria parasite, Plasmodium falciparum, in human red blood cells

1992 ◽  
Vol 102 (3) ◽  
pp. 527-532 ◽  
Author(s):  
A.R. Dluzewski ◽  
G.H. Mitchell ◽  
P.R. Fryer ◽  
S. Griffiths ◽  
R.J. Wilson ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Cell Membrane ◽  
Host Cell ◽  
Malaria Parasite ◽  
Parasitophorous Vacuole ◽  
Parasitophorous Vacuole Membrane ◽  
Host Cell Membrane ◽  
Vacuole Membrane ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum

We have attempted to determine whether the parasitophorous vacuole membrane, in which the malaria parasite (merozoite) encapsulates itself when it enters a red blood cell, is derived from the host cell plasma membrane, as the appearance of the invasion process in the electron microscope has been taken to suggest, or from lipid material stored in the merozoite. We have incorporated into the red cell membrane a haptenic phospholipid, phosphatidylethanolamine, containing an NBD (N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)) group, substituted in the acyl chain, and allowed it to translocate into the inner bilayer leaflet. After invasion of these labelled cells by the parasite, Plasmodium falciparum, immuno-gold electron microscopy was used to follow the distribution of the labelled lipid; this was found to be overwhelmingly in favour of the host cell membrane relative to the parasitophorous vacuole. Merozoites of P. knowlesi were allowed to attach irreversibly to red cells without invasion, using the method of pretreatment with cytochalasin. The region of contact between the merozoite and the host cell membrane was in all cases devoid of the labelled phosphatidylethanolamine. These results lead us to infer that the parasitophorous vacuole membrane is derived wholly or partly from lipid preexisting in the merozoite.

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