Transbilayer phospholipid asymmetry in Plasmodium knowlesi-infected host cell membrane

Science ◽  
1981 ◽  
Vol 212 (4498) ◽  
pp. 1047-1049 ◽  
Author(s):  
C. Gupta ◽  
G. Mishra
Keyword(s):  
Cell Membrane ◽  
Host Cell ◽  
Plasmodium Knowlesi ◽  
Infected Host ◽  
Host Cell Membrane ◽  
Infected Host Cell ◽  
Phospholipid Asymmetry

scholarly journals Exaptation of Retroviral Syncytin for Development of Syncytialized Placenta, Its Limited Homology to the SARS-CoV-2 Spike Protein and Arguments against Disturbing Narrative in the Context of COVID-19 Vaccination

Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 238
Author(s):  
Malgorzata Kloc ◽  
Ahmed Uosef ◽  
Jacek Z. Kubiak ◽  
Rafik M. Ghobrial
Keyword(s):  
Cell Membrane ◽  
Host Cell ◽  
Envelope Glycoprotein ◽  
Mammalian Species ◽  
Viral Envelope ◽  
Spike Protein ◽  
Mammalian Evolution ◽  
Trophoblast Cells ◽  
Host Cell Membrane ◽  
Uterine Endometrium

Human placenta formation relies on the interaction between fused trophoblast cells of the embryo with uterine endometrium. The fusion between trophoblast cells, first into cytotrophoblast and then into syncytiotrophoblast, is facilitated by the fusogenic protein syncytin. Syncytin derives from an envelope glycoprotein (ENV) of retroviral origin. In exogenous retroviruses, the envelope glycoproteins coded by env genes allow fusion of the viral envelope with the host cell membrane and entry of the virus into a host cell. During mammalian evolution, the env genes have been repeatedly, and independently, captured by various mammalian species to facilitate the formation of the placenta. Such a shift in the function of a gene, or a trait, for a different purpose during evolution is called an exaptation (co-option). We discuss the structure and origin of the placenta, the fusogenic and non-fusogenic functions of syncytin, and the mechanism of cell fusion. We also comment on an alleged danger of the COVID-19 vaccine based on the presupposed similarity between syncytin and the SARS-CoV-2 spike protein.

scholarly journals Intracellular host cell membrane remodelling induced by SARS‐CoV‐2 infection in vitro

2021 ◽  
Author(s):  
Lucio Ayres Caldas ◽  
Fabiana Avila Carneiro ◽  
Fabio Luis Monteiro ◽  
Ingrid Augusto ◽  
Luiza Mendonça Higa ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Host Cell ◽  
Host Cell Membrane

scholarly journals Redistribution of Parasite and Host Cell Membrane Components during Toxoplasma gondii Invasion.

1998 ◽  
Vol 23 (3) ◽  
pp. 159-168 ◽  
Author(s):  
Cristina Pacheco-Soares ◽  
Wanderley De Souza
Keyword(s):  
Toxoplasma Gondii ◽  
Cell Membrane ◽  
Host Cell ◽  
Host Cell Membrane ◽  
Membrane Components

scholarly journals Entropic Forces Drive Clustering and Spatial Localization of Influenza A M2 During Viral Budding

2018 ◽  
Author(s):  
Jesper J. Madsen ◽  
John M. A. Grime ◽  
Jeremy S. Rossman ◽  
Gregory A. Voth
Keyword(s):  
Host Cell ◽  
Influenza A ◽  
Spatial Localization ◽  
Membrane Curvature ◽  
Infected Host ◽  
Membrane Remodeling ◽  
Infected Host Cell ◽  
Viral Budding ◽  
Virion Release ◽  
Liquid Ordered

ABSTRACTThe influenza A matrix 2 (M2) transmembrane protein facilitates virion release from the infected host cell. In particular, M2 plays a role in the induction of membrane curvature and/or in the scission process whereby the envelope is cut upon virion release. Here we show using coarse-grained computer simulations that various M2 assembly geometries emerge due to an entropic driving force, resulting in compact clusters or linearly extended aggregates as a direct consequence of the lateral membrane stresses. Conditions under which these protein assemblies will cause the lipid membrane to curve are explored and we predict that a critical cluster size is required for this to happen. We go on to demonstrate that under the stress conditions taking place in the cellular membrane as it undergoes large-scale membrane remodeling, the M2 protein will in principle be able to both contribute to curvature induction and sense curvature in order to line up in manifolds where local membrane line tension is high. M2 is found to exhibit linactant behavior in liquid-disordered/liquid-ordered phase-separated lipid mixtures and to be excluded from the liquid-ordered phase, in near-quantitative agreement with experimental observations. Our findings support a role for M2 in membrane remodeling during influenza viral budding both as an inducer and a sensor of membrane curvature, and they suggest a mechanism by which localization of M2 can occur as the virion assembles and releases from the host cell, independent of how the membrane curvature is produced.SIGNIFICANCE STATEMENTFor influenza virus to release from the infected host cell, controlled viral budding must finalize with membrane scission of the viral envelope. Curiously, influenza carries its own protein, M2, which can sever the membrane of the constricted budding neck. Here we elucidate the physical mechanism of clustering and spatial localization of the M2 scission proteins through a combined computational and experimental approach. Our results provide fundamental insights into how M2 clustering and localization interplays with membrane curvature, membrane lateral stresses, and lipid bilayer phase behavior during viral budding in order to contribute to virion release.

scholarly journals The Photorhabdus asymbiotica virulence cassettes deliver protein effectors directly into target eukaryotic cells

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Isabella Vlisidou ◽  
Alexia Hapeshi ◽  
Joseph RJ Healey ◽  
Katie Smart ◽  
Guowei Yang ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Host Cell ◽  
Small Molecule ◽  
Rho Gtpase ◽  
Eukaryotic Cells ◽  
Host Cell Membrane ◽  
Western Blots ◽  
Insect Pathogen ◽  
Protein Toxins ◽  
Delivery Mechanism

Photorhabdus is a highly effective insect pathogen and symbiont of insecticidal nematodes. To exert its potent insecticidal effects, it elaborates a myriad of toxins and small molecule effectors. Among these, the Photorhabdus Virulence Cassettes (PVCs) represent an elegant self-contained delivery mechanism for diverse protein toxins. Importantly, these self-contained nanosyringes overcome host cell membrane barriers, and act independently, at a distance from the bacteria itself. In this study, we demonstrate that Pnf, a PVC needle complex associated toxin, is a Rho-GTPase, which acts via deamidation and transglutamination to disrupt the cytoskeleton. TEM and Western blots have shown a physical association between Pnf and its cognate PVC delivery mechanism. We demonstrate that for Pnf to exert its effect, translocation across the cell membrane is absolutely essential.

scholarly journals Recombinant single chain antibodies as an instrument to search proteins involved in the interaction of microsporidia and other intracellular parasites with an infected host cell

Protistology ◽  
2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Alexander A. Tsarev ◽  
◽  
Igorj V Senderskiy ◽  
Sergei A. Timofeev ◽  
Vladimir S. Zhuravlyov ◽  
...  
Keyword(s):  
Host Cell ◽  
Infected Host ◽  
Single Chain ◽  
Single Chain Antibodies ◽  
Infected Host Cell ◽  
Intracellular Parasites

scholarly journals Membrane and luminal proteins reach the apicoplast by different trafficking pathways in the malaria parasite Plasmodium falciparum

2017 ◽  
Author(s):  
Rahul Chaudhari ◽  
Vishakha Dey ◽  
Aishwarya Narayan ◽  
Shobhona Sharma ◽  
Swati Patankar
Keyword(s):  
Plasmodium Falciparum ◽  
Cell Membrane ◽  
Membrane Protein ◽  
Host Cell ◽  
G Protein ◽  
Secretory Pathway ◽  
Protein Targeting ◽  
Acyl Carrier Protein ◽  
Secretory Proteins ◽  
Host Cell Membrane

The secretory pathway in Plasmodium falciparum has evolved to transport proteins to the host cell membrane and to an endosymbiotic organelle, the apicoplast. The latter can occur via the ER or the ER-Golgi route. Here, we study these three routes using proteins Erythrocyte Membrane Protein-1 (PfEMP1), Acyl Carrier Protein (ACP) and glutathione peroxidase-like thioredoxin peroxidase (PfTPxGl) and inhibitors of vesicular transport. As expected, the G protein dependent vesicular fusion inhibitor AlF4- and microtubule destabilizing drug vinblastine block the trafficking of PfEMP-1, a protein secreted to the host cell membrane. However, while both PfTPxGl and ACP are targeted to the apicoplast, only ACP trafficking remains unaffected by these treatments. This implies that G-protein dependent vesicles do not play a role in classical apicoplast protein targeting. Unlike the soluble protein ACP, we show that PfTPxGl is localized to the outermost membrane of the apicoplast. Thus, the parasite apicoplast acquires proteins via two different pathways: first, the vesicular trafficking pathway appears to handle not only secretory proteins, but an apicoplast membrane protein, PfTPxGl. Second, trafficking of apicoplast luminal proteins appear to be independent of G-protein coupled vesicles.

scholarly journals Membrane and luminal proteins reach the apicoplast by different trafficking pathways in the malaria parasite Plasmodium falciparum

2017 ◽  
Author(s):  
Rahul Chaudhari ◽  
Vishakha Dey ◽  
Aishwarya Narayan ◽  
Shobhona Sharma ◽  
Swati Patankar
Keyword(s):  
Plasmodium Falciparum ◽  
Cell Membrane ◽  
Membrane Protein ◽  
Host Cell ◽  
G Protein ◽  
Secretory Pathway ◽  
Protein Targeting ◽  
Acyl Carrier Protein ◽  
Secretory Proteins ◽  
Host Cell Membrane

The secretory pathway in Plasmodium falciparum has evolved to transport proteins to the host cell membrane and to an endosymbiotic organelle, the apicoplast. The latter can occur via the ER or the ER-Golgi route. Here, we study these three routes using proteins Erythrocyte Membrane Protein-1 (PfEMP1), Acyl Carrier Protein (ACP) and glutathione peroxidase-like thioredoxin peroxidase (PfTPxGl) and inhibitors of vesicular transport. As expected, the G protein dependent vesicular fusion inhibitor AlF4- and microtubule destabilizing drug vinblastine block the trafficking of PfEMP-1, a protein secreted to the host cell membrane. However, while both PfTPxGl and ACP are targeted to the apicoplast, only ACP trafficking remains unaffected by these treatments. This implies that G-protein dependent vesicles do not play a role in classical apicoplast protein targeting. Unlike the soluble protein ACP, we show that PfTPxGl is localized to the outermost membrane of the apicoplast. Thus, the parasite apicoplast acquires proteins via two different pathways: first, the vesicular trafficking pathway appears to handle not only secretory proteins, but an apicoplast membrane protein, PfTPxGl. Second, trafficking of apicoplast luminal proteins appear to be independent of G-protein coupled vesicles.

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