scholarly journals Characterization of the Neospora caninum NcROP40 and NcROP2Fam-1 rhoptry proteins during the tachyzoite lytic cycle

Parasitology ◽  
2015 ◽  
Vol 143 (1) ◽  
pp. 97-113 ◽  
Author(s):  
IVÁN PASTOR-FERNÁNDEZ ◽  
JAVIER REGIDOR-CERRILLO ◽  
ELENA JIMÉNEZ-RUIZ ◽  
GEMA ÁLVAREZ-GARCÍA ◽  
VIRGINIA MARUGÁN-HERNÁNDEZ ◽  
...  
Keyword(s):  
Neospora Caninum ◽  
Parasitophorous Vacuole ◽  
Lytic Cycle ◽  
Mrna Levels ◽  
Amphipathic Helix ◽  
Parasitophorous Vacuole Membrane ◽  
Vaccine Candidates ◽  
Vacuole Membrane

SUMMARYVirulence factors from the ROP2-family have been extensively studied in Toxoplasma gondii, but in the closely related Neospora caninum only NcROP2Fam-1 has been partially characterized to date. NcROP40 is a member of this family and was found to be more abundantly expressed in virulent isolates. Both NcROP2Fam-1 and NcROP40 were evaluated as vaccine candidates and exerted a synergistic effect in terms of protection against vertical transmission in mouse models, which suggests that they may be relevant for parasite pathogenicity. NcROP40 is localized in the rhoptry bulbs of tachyzoites and bradyzoites, but in contrast to NcROP2Fam-1, the protein does not associate with the parasitophorous vacuole membrane due to the lack of arginine-rich amphipathic helix in its sequence. Similarly to NcROP2Fam-1, NcROP40 mRNA levels are highly increased during tachyzoite egress and invasion. However, NcROP40 up-regulation does not appear to be linked to the mechanisms triggering egress. In contrast to NcROP2Fam-1, phosphorylation of NcROP40 was not observed during egress. Besides, NcROP40 secretion into the host cell was not successfully detected by immunofluorescence techniques. These findings indicate that NcROP40 and NcROP2Fam-1 carry out different functions, and highlight the need to elucidate the role of NcROP40 within the lytic cycle and to explain its relative abundance in tachyzoites.

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

Chemical characterization of the parasitophorous vacuole membrane antigen QF 116 from Plasmodium falciparum

1990 ◽  
Vol 38 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Ursula Kara ◽  
Brendan Murray ◽  
Christine Pam ◽  
Jelle Lahnstein ◽  
Heather Gould ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Parasitophorous Vacuole ◽  
Chemical Characterization ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane

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

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.

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.

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