scholarly journals The parasitophorous vacuole membrane surrounding intracellular Toxoplasma gondii functions as a molecular sieve.

1994 ◽  
Vol 91 (2) ◽  
pp. 509-513 ◽  
Author(s):  
J. C. Schwab ◽  
C. J. Beckers ◽  
K. A. Joiner
Keyword(s):  
Toxoplasma Gondii ◽  
Molecular Sieve ◽  
Parasitophorous Vacuole ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane

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.

scholarly journals The Toxoplasma gondii protein ROP2 mediates host organelle association with the parasitophorous vacuole membrane

2001 ◽  
Vol 154 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Anthony P. Sinai ◽  
Keith A. Joiner
Keyword(s):  
Toxoplasma Gondii ◽  
Fluorescent Protein ◽  
Parasitophorous Vacuole ◽  
Host Cells ◽  
In Vitro Assays ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Targeting ◽  
Parasitophorous Vacuole Membrane ◽  
Parasite Protein ◽  
Vacuole Membrane

Toxoplasma gondii replicates within a specialized vacuole surrounded by the parasitophorous vacuole membrane (PVM). The PVM forms intimate interactions with host mitochondria and endoplasmic reticulum (ER) in a process termed PVM–organelle association. In this study we identify a likely mediator of this process, the parasite protein ROP2. ROP2, which is localized to the PVM, is secreted from anterior organelles termed rhoptries during parasite invasion into host cells. The NH2-terminal domain of ROP2 (ROP2hc) within the PVM is exposed to the host cell cytosol, and has characteristics of a mitochondrial targeting signal. In in vitro assays, ROP2hc is partially translocated into the mitochondrial outer membrane and behaves like an integral membrane protein. Although ROP2hc does not translocate across the ER membrane, it does exhibit carbonate-resistant binding to this organelle. In vivo, ROP2hc expressed as a soluble fragment in the cytosol of uninfected cells associates with both mitochondria and ER. The 30–amino acid (aa) NH2-terminal sequence of ROP2hc, when fused to green fluorescent protein (GFP), is sufficient for mitochondrial targeting. Deletion of the 30-aa NH2-terminal signal from ROP2hc results in robust localization of the truncated protein to the ER. These results demonstrate a new mechanism for tight association of different membrane-bound organelles within the cell cytoplasm.

Molecular structure of a Toxoplasma gondii dense granule antigen (GRA 5) associated with the parasitophorous vacuole membrane

1993 ◽  
Vol 59 (1) ◽  
pp. 143-153 ◽  
Author(s):  
Laurence Lecordier ◽  
Corinne Mercier ◽  
Gérard Torpier ◽  
Béatrice Tourvieille ◽  
Francoise Darcy ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Toxoplasma Gondii ◽  
Parasitophorous Vacuole ◽  
Dense Granule ◽  
Parasitophorous Vacuole Membrane ◽  
Vacuole Membrane

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 Guanylate binding proteins directly attack Toxoplasma gondii via supramolecular complexes

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Elisabeth Kravets ◽  
Daniel Degrandi ◽  
Qijun Ma ◽  
Thomas-Otavio Peulen ◽  
Verena Klümpers ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Parasitophorous Vacuole ◽  
Supramolecular Complexes ◽  
Parasitophorous Vacuole Membrane ◽  
Gtp Hydrolysis ◽  
Fluorescence Image ◽  
Vacuole Membrane ◽  
Live Cell Microscopy ◽  
Image Spectroscopy ◽  
Cell Microscopy

GBPs are essential for immunity against intracellular pathogens, especially for Toxoplasma gondii control. Here, the molecular interactions of murine GBPs (mGBP1/2/3/5/6), homo- and hetero-multimerization properties of mGBP2 and its function in parasite killing were investigated by mutational, Multiparameter Fluorescence Image Spectroscopy, and live cell microscopy methodologies. Control of T. gondii replication by mGBP2 requires GTP hydrolysis and isoprenylation thus, enabling reversible oligomerization in vesicle-like structures. mGBP2 undergoes structural transitions between monomeric, dimeric and oligomeric states visualized by quantitative FRET analysis. mGBPs reside in at least two discrete subcellular reservoirs and attack the parasitophorous vacuole membrane (PVM) as orchestrated, supramolecular complexes forming large, densely packed multimers comprising up to several thousand monomers. This dramatic mGBP enrichment results in the loss of PVM integrity, followed by a direct assault of mGBP2 upon the plasma membrane of the parasite. These discoveries provide vital dynamic and molecular perceptions into cell-autonomous immunity.

Sign in / Sign up

Export Citation Format

Share Document