scholarly journals Implication of Potential Differential Roles of the Two Phosphoglucomutase Isoforms in the Protozoan Parasite Cryptosporidium parvum

Pathogens ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Jiawen Nie ◽  
Jigang Yin ◽  
Dongqiang Wang ◽  
Chenchen Wang ◽  
Guan Zhu
Keyword(s):  
Enzyme Activity ◽  
Recombinant Proteins ◽  
Cryptosporidium Parvum ◽  
Plasma Membranes ◽  
Parasitophorous Vacuole ◽  
Protozoan Parasite ◽  
Immunofluorescence Assay ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane ◽  
Intracellular Parasites

Phosphoglucomutase 1 (PGM1) catalyzes the conversion between glucose-1-phosphate and glucose-6-phosphate in the glycolysis/glucogenesis pathway. PGM1s are typically cytosolic enzymes in organisms lacking chloroplasts. However, the protozoan Cryptosporidium parasites possess two tandemly duplicated PGM1 genes evolved by a gene duplication after their split from other apicomplexans. Moreover, the downstream PGM1 isoform contains an N-terminal signal peptide, predicting a non-cytosolic location. Here we expressed recombinant proteins of the two PGM1 isoforms from the zoonotic Cryptosporidium parvum, namely CpPGM1A and CpPGM1B, and confirmed their enzyme activity. Both isoforms followed Michaelis–Menten kinetics towards glucose-1-phosphate (Km = 0.17 and 0.13 mM, Vmax = 7.30 and 2.76 μmol/min/mg, respectively). CpPGM1A and CpPGM1B genes were expressed in oocysts, sporozoites and intracellular parasites at a similar pattern of expression, however CpPGM1A was expressed at much higher levels than CpPGM1B. Immunofluorescence assay showed that CpPGM1A was present in the cytosol of sporozoites, however this was enriched towards the plasma membranes in the intracellular parasites; whereas CpPGM1B was mainly present under sporozoite pellicle, although relocated to the parasitophorous vacuole membrane in the intracellular development. These observations indicated that CpPGM1A played a house-keeping function, while CpPGM1B played a different biological role that remains to be defined by future investigations.

Association of host cell endoplasmic reticulum and mitochondria with the Toxoplasma gondii parasitophorous vacuole membrane: a high affinity interaction

1997 ◽  
Vol 110 (17) ◽  
pp. 2117-2128 ◽  
Author(s):  
A.P. Sinai ◽  
P. Webster ◽  
K.A. Joiner
Keyword(s):  
Endoplasmic Reticulum ◽  
Toxoplasma Gondii ◽  
Host Cell ◽  
Parasitophorous Vacuole ◽  
Protozoan Parasite ◽  
Host Cells ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane ◽  
Protein Protein Interaction ◽  
High Affinity

The parasitophorous vacuole membrane (PVM) of the obligate intracellular protozoan parasite Toxoplasma gondii forms tight associations with host mitochondria and the endoplasmic reticulum (ER). We have used a combination of morphometric and biochemical approaches to characterize this unique phenomenon, which we term PVM-organelle association. The PVM is separated from associated mitochondria and ER by a mean distance of 12 and 18 nm, respectively. The establishment of PVM-organelle association is dependent on active parasite entry, but does not require parasite viability for its maintenance. Association is not a consequence of spatial constraints imposed on the growing vacuole. Morphometric analysis indicates that the extent of mitochondrial association with the PVM stays constant as the vacuole enlarges, whereas the extent of ER association decreases. Disruption of host cell microtubules partially blocks the establishment but not the maintenance of PVM-mitochondrial association, and has no significant effect on PVM-ER association. PVM-organelle association is maintained following disruption of infected host cells, as assessed by electron microscopy and by sub-cellular fractionation showing co-migration of fixed PVM and organelle markers. Taken together, the data suggest that a high affinity, potentially protein-protein interaction between parasite and organelle components is responsible for PVM-organelle association.

Toxoplasma Mechanisms for Delivery of Proteins and Uptake of Nutrients Across the Host-Pathogen Interface

2020 ◽  
Vol 74 (1) ◽  
pp. 567-586 ◽  
Author(s):  
Yifan Wang ◽  
Lamba Omar Sangaré ◽  
Tatiana C. Paredes-Santos ◽  
Jeroen P. J. Saeij
Keyword(s):  
Pattern Recognition ◽  
Toxoplasma Gondii ◽  
Parasitophorous Vacuole ◽  
Protozoan Parasite ◽  
Intracellular Pathogens ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane ◽  
Pathogen Effectors ◽  
Host Pathogen ◽  
Uptake Of Nutrients

Many intracellular pathogens, including the protozoan parasite Toxoplasma gondii, live inside a vacuole that resides in the host cytosol. Vacuolar residence provides these pathogens with a defined niche for replication and protection from detection by host cytosolic pattern recognition receptors. However, the limiting membrane of the vacuole, which constitutes the host-pathogen interface, is also a barrier for pathogen effectors to reach the host cytosol and for the acquisition of host-derived nutrients. This review provides an update on the specialized secretion and trafficking systems used by Toxoplasma to overcome the barrier of the parasitophorous vacuole membrane and thereby allow the delivery of proteins into the host cell and the acquisition of host-derived nutrients.

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 Cryptosporidium parvum gp40/15 Is Associated with the Parasitophorous Vacuole Membrane and Is a Potential Vaccine Target

2020 ◽  
Vol 8 (3) ◽  
pp. 363
Author(s):  
Zhaohui Cui ◽  
Luyang Wang ◽  
Yuexin Wang ◽  
Juan Li ◽  
Rongjun Wang ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Molecular Mechanisms ◽  
Protein Localization ◽  
Parasitophorous Vacuole ◽  
Expression Patterns ◽  
Surface Proteins ◽  
Host Cells ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane

Cryptosporidium parvum is a zoonotic intracellular protozoan responsible for the diarrheal illness cryptosporidiosis in humans and animals. Although a number of zoite surface proteins are known to be expressed during, and believed to be involved in, attachment and invasion of host cells, the molecular mechanisms by which C. parvum invades the host epithelial cells are not well understood. In the present study, we investigated the gene expression patterns, protein localization in developmental stages in culture, and in vitro neutralization characteristics of Cpgp40/15 and Cpgp40. Indirect immunofluorescence assay showed that Cpgp40/15 is associated with the parasitophorous vacuole membrane (PVM) during intracellular development. Both anti-gp40/15 and anti-gp40 antibodies demonstrated the ability to neutralize C. parvum infection in vitro. Further studies are needed to fully understand the specific role and functional mechanism of Cpgp40/15 (or gp40/15 complex) in the invasion of the host or in the PVM and to determine the feasibility of gp40/15 as a vaccine candidate for cryptosporidiosis in vivo.

scholarly journals EXP1 is critical for nutrient uptake across the parasitophorous vacuole membrane of malaria parasites

PLoS Biology ◽  
2019 ◽  
Vol 17 (9) ◽  
pp. e3000473 ◽  
Author(s):  
Paolo Mesén-Ramírez ◽  
Bärbel Bergmann ◽  
Thuy Tuyen Tran ◽  
Matthias Garten ◽  
Jan Stäcker ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Parasitophorous Vacuole ◽  
Parasitophorous Vacuole Membrane ◽  
Malaria Parasites ◽  
Vacuole Membrane

Differential targeting of dense granule proteins in the parasitophorous vacuole ofToxoplasma gondii

Parasitology ◽  
1991 ◽  
Vol 103 (3) ◽  
pp. 321-329 ◽  
Author(s):  
A. Achbarou ◽  
O. Mercereau-Puijalon ◽  
A. Sadak ◽  
B. Fortier ◽  
M. A. Leriche ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Parasitophorous Vacuole ◽  
Dense Granule ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane ◽  
Molecular Weights ◽  
Dense Granules ◽  
Metabolic Labelling ◽  
Infected Cells ◽  
Granule Proteins

The biosynthesis and fate of 4 different dense granule proteins ofToxoplasma gondiiwere studied with 3 monoclonal antibodies raised against tachyzoites and 1 polyclonal antibody raised against a recombinant protein. These proteins have the following molecular weights: 27 kDa (GRA 1), 28 kDa (GRA 2), 30 kDa (GRA 3) and 40 kDa (GRA 4). All four proteins were found in dense granules by immunoelectron microscopy; inT. gondii-infected cells, they were found in the vacuolar network but, in addition, GRA 3 was also detected on the parasitophorous vacuole membrane. Therefore, dense granule contents undergo differential targeting when exocytosed in the parasitophorous vacuole. Metabolic labelling and immunoprecipitation showed that GRA 2 and GRA 3 were processed from lower molecular weight precursors, and that GRA 2 and GRA 4 incorporated [3H] glucosamine and are thus likely to be glycosylated.

scholarly journals Plasmodium berghei Δp52&p36 Parasites Develop Independent of a Parasitophorous Vacuole Membrane in Huh-7 Liver Cells

PLoS ONE ◽  
2012 ◽  
Vol 7 (12) ◽  
pp. e50772 ◽  
Author(s):  
Ivo H. J. Ploemen ◽  
Huib J. Croes ◽  
Geert-Jan J. van Gemert ◽  
Mietske Wijers-Rouw ◽  
Cornelus C. Hermsen ◽  
...  
Keyword(s):  
Plasmodium Berghei ◽  
Parasitophorous Vacuole ◽  
Liver Cells ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane
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