scholarly journals Plasmodium falciparum PF10_0164 (ETRAMP10.3) Is an Essential Parasitophorous Vacuole and Exported Protein in Blood Stages

2010 ◽  
Vol 9 (5) ◽  
pp. 784-794 ◽  
Author(s):  
Drew C. MacKellar ◽  
Matthew T. O'Neill ◽  
Ahmed S. I. Aly ◽  
John B. Sacci ◽  
Alan F. Cowman ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Parasitophorous Vacuole ◽  
Structural Similarity ◽  
Plasmodium Yoelii ◽  
Parasitophorous Vacuole Membrane ◽  
Liver Stage ◽  
Content Type ◽  
Vacuole Membrane ◽  
Stage Development ◽  
Gene 4

ABSTRACT Upregulated in infectious sporozoites gene 4 (UIS4) encodes a parasitophorous vacuole membrane protein expressed in the sporozoite and liver stages of rodent malaria parasites. Parasites that lack UIS4 arrest in early liver-stage development, and vaccination of mice with uis4 − sporozoites confers sterile protection against challenge with infectious sporozoites. Currently, it remains unclear whether an ortholog of UIS4 is carried in the human malaria parasite Plasmodium falciparum, although the gene PF10_0164 has been identified as a candidate ortholog for UIS4 on the basis of synteny and structural similarity of the encoded protein. We show that PF10_0164 is expressed in sporozoites and blood stages of P. falciparum, where it localizes to the parasitophorous vacuole, and is also exported to the host erythrocyte. PF10_0164 is refractory to disruption in asexual blood stages. Functional complementation was tested in Plasmodium yoelii by replacing the endogenous copy of UIS4 with PF10_0164. PF10_0164 localized to the parasitophorous vacuole membrane of liver stages, but transgenic parasites did not complete liver-stage development in mice. We conclude that PF10_0164 is a parasitophorous vacuole protein that is essential in asexual blood stages and that does not complement P. yoelii UIS4, and it is thus likely not a functional ortholog of UIS4.

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.

scholarly journals A Plasmodium yoelii Mei2-Like RNA Binding Protein Is Essential for Completion of Liver Stage Schizogony

2016 ◽  
Vol 84 (5) ◽  
pp. 1336-1345 ◽  
Author(s):  
Dorender A. Dankwa ◽  
Marshall J. Davis ◽  
Stefan H. I. Kappe ◽  
Ashley M. Vaughan
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Plasmodium Yoelii ◽  
Parasite Development ◽  
Mammalian Host ◽  
Mosquito Vector ◽  
Wild Type ◽  
Liver Stage ◽  
Content Type ◽  
Stage Development

Plasmodiumparasites employ posttranscriptional regulatory mechanisms as their life cycle transitions between host cell invasion and replication within both the mosquito vector and mammalian host. RNA binding proteins (RBPs) provide one mechanism for modulation of RNA function. To explore the role ofPlasmodiumRBPs during parasite replication, we searched for RBPs that might play a role during liver stage development, the parasite stage that exhibits the most extensive growth and replication. We identified a parasite ortholog of theMei2(Meiosisinhibited 2) RBP that is conserved amongPlasmodiumspecies (PlasMei2) and exclusively transcribed in liver stage parasites. Epitope-taggedPlasmodium yoeliiPlasMei2 was expressed only during liver stage schizogony and showed an apparent granular cytoplasmic location. Knockout ofPlasMei2(plasmei2−) inP. yoeliionly affected late liver stage development. TheP. yoeliiplasmei2−liver stage size increased progressively until late in development, similar to wild-type parasite development. However,P. yoeliiplasmei2−liver stage schizonts exhibited an abnormal DNA segregation phenotype and failed to form exoerythrocytic merozoites. Consequently the cellular integrity ofP. yoeliiplasmei2−liver stages became increasingly compromised late in development and the majority ofP. yoeliiplasmei2−underwent cell death by the time wild-type liver stages mature and release merozoites. This resulted in a complete block ofP. yoeliiplasmei2−transition from liver stage to blood stage infection in mice. Our results show for the first time the importance of aPlasmodiumRBP in the coordinated progression of late liver stage schizogony and maturation of new invasive forms.

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 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.

scholarly journals Rab5b-Associated Arf1 GTPase Regulates Export of N-Myristoylated Adenylate Kinase 2 From the Endoplasmic Reticulum in Plasmodium falciparum

2021 ◽  
Vol 10 ◽  
Author(s):  
Izumi Taku ◽  
Tomohiro Hirai ◽  
Takashi Makiuchi ◽  
Naoaki Shinzawa ◽  
Shiroh Iwanaga ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasmodium Falciparum ◽  
Membrane Trafficking ◽  
Adenylate Kinase ◽  
Parasitophorous Vacuole ◽  
Super Resolution ◽  
Immunofluorescence Assay ◽  
Rab Gtpases ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane

Plasmodium falciparum extensively remodels human erythrocytes by exporting hundreds of parasite proteins. This remodeling is closely linked to the Plasmodium virulence-related functions and immune evasion. The N-terminal export signal named PEXEL (Plasmodium export element) was identified to be important for the export of proteins beyond the PVM, however, the issue of how these PEXEL-positive proteins are transported and regulated by Rab GTPases from the endoplasmic reticulum (ER) to the cell surface has remained poorly understood. Previously, we identified new aspects of the trafficking of N-myristoylated adenylate kinase 2 (PfAK2), which lacks the PEXEL motif and is regulated by the PfRab5b GTPase. Overexpression of PfRab5b suppressed the transport of PfAK2 to the parasitophorous vacuole membrane and PfAK2 was accumulated in the punctate compartment within the parasite. Here, we report the identification of PfRab5b associated proteins and dissect the pathway regulated by PfRab5b. We isolated two membrane trafficking GTPases PfArf1 and PfRab1b by coimmunoprecipitation with PfRab5b and via mass analysis. PfArf1 and PfRab1b are both colocalized with PfRab5b adjacent to the ER in the early erythrocytic stage. A super-resolution microgram of the indirect immunofluorescence assay using PfArf1 or PfRab1b- expressing parasites revealed that PfArf1 and PfRab1b are localized to different ER subdomains. We used a genetic approach to expresses an active or inactive mutant of PfArf1 that specifically inhibited the trafficking of PfAK2 to the parasitophorous vacuole membrane. While expression of PfRab1b mutants did not affect in the PfAK2 transport. In contrast, the export of the PEXEL-positive protein Rifin was decreased by the expression of the inactive mutant of PfRab1b or PfArf1. These data indicate that the transport of PfAK2 and Rifin were recognized at the different ER subdomain by the two independent GTPases: PfAK2 is sorted by PfArf1 into the pathway for the PV, and the export of Rifin might be sequentially regulated by PfArf1 and PfRab1b.

scholarly journals Exp2 in the Role of the Small Molecule Pore in the Parasitophorous Vacuole Membrane of Plasmodium falciparum

2018 ◽  
Vol 114 (3) ◽  
pp. 492a ◽  
Author(s):  
Matthias Garten ◽  
Josh R. Beck ◽  
Svetlana Glushakova ◽  
Armiyaw S. Nasamu ◽  
Jacquin C. Niles ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Small Molecule ◽  
Parasitophorous Vacuole ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane

scholarly journals In VitroAlterations Do Not Reflect a Requirement for Host Cell Cycle Progression during Plasmodium Liver Stage Infection

2014 ◽  
Vol 14 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Kirsten K. Hanson ◽  
Sandra March ◽  
Shengyong Ng ◽  
Sangeeta N. Bhatia ◽  
Maria M. Mota
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Hepatoma Cells ◽  
Plasmodium Yoelii ◽  
Host Cells ◽  
Cycle Progression ◽  
Liver Stage ◽  
Content Type ◽  
Stage Development ◽  
Stage Infection

ABSTRACTPrior to invading nonreplicative erythrocytes,Plasmodiumparasites undergo their first obligate step in the mammalian host inside hepatocytes, where each sporozoite replicates to generate thousands of merozoites. While normally quiescent, hepatocytes retain proliferative capacity and can readily reenter the cell cycle in response to diverse stimuli. Many intracellular pathogens, including protozoan parasites, manipulate the cell cycle progression of their host cells for their own benefit, but it is not known whether the hepatocyte cell cycle plays a role duringPlasmodiumliver stage infection. Here, we show thatPlasmodiumparasites can be observed in mitotic hepatoma cells throughout liver stage development, where they initially reduce the likelihood of mitosis and ultimately lead to significant acquisition of a binucleate phenotype. However, hepatoma cells pharmacologically arrested in S phase still support robust and completePlasmodiumliver stage development, which thus does not require cell cycle progression in the infected cellin vitro. Furthermore, murine hepatocytes remain quiescent throughoutin vivoinfection with eitherPlasmodium bergheiorPlasmodium yoelii, as doPlasmodium falciparum-infected primary human hepatocytes, demonstrating that the rapid and prodigious growth of liver stage parasites is accomplished independent of host hepatocyte cell cycle progression during natural infection.

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