scholarly journals Remodeling of the Host Cell Plasma Membrane by HIV-1 Nef and Vpu: A Strategy to Ensure Viral Fitness and Persistence

Viruses ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 67 ◽  
Author(s):  
Scott Sugden ◽  
Mariana Bego ◽  
Tram Pham ◽  
Éric Cohen
Keyword(s):  
Plasma Membrane ◽  
Host Cell ◽  
Viral Fitness ◽  
Cell Plasma Membrane ◽  
Cell Plasma ◽  
Hiv 1

scholarly journals Monitoring HIV-1 Assembly in Living Cells: Insights from Dynamic and Single Molecule Microscopy

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 72 ◽  
Author(s):  
Kaushik Inamdar ◽  
Charlotte Floderer ◽  
Cyril Favard ◽  
Delphine Muriaux
Keyword(s):  
Plasma Membrane ◽  
Host Cell ◽  
Single Molecule ◽  
High Speed ◽  
Time Course ◽  
Molecular Mechanisms ◽  
Living Cells ◽  
Cell Plasma Membrane ◽  
Cell Plasma ◽  
Hiv 1

The HIV-1 assembly process is a multi-complex mechanism that takes place at the host cell plasma membrane. It requires a spatio-temporal coordination of events to end up with a full mature and infectious virus. The molecular mechanisms of HIV-1 assembly have been extensively studied during the past decades, in order to dissect the respective roles of the structural and non-structural viral proteins of the viral RNA genome and of some host cell factors. Nevertheless, the time course of HIV-1 assembly was observed in living cells only a decade ago. The very recent revolution of optical microscopy, combining high speed and high spatial resolution, in addition to improved fluorescent tags for proteins, now permits study of HIV-1 assembly at the single molecule level within living cells. In this review, after a short description of these new approaches, we will discuss how HIV-1 assembly at the cell plasma membrane has been revisited using advanced super resolution microscopy techniques and how it can bridge the study of viral assembly from the single molecule to the entire host cell.

scholarly journals Host Cell Plasma Membrane Phosphatidylserine Regulates the Assembly and Budding of Ebola Virus

2015 ◽  
Vol 89 (18) ◽  
pp. 9440-9453 ◽  
Author(s):  
Emmanuel Adu-Gyamfi ◽  
Kristen A. Johnson ◽  
Mark E. Fraser ◽  
Jordan L. Scott ◽  
Smita P. Soni ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Host Cell ◽  
Human Cell ◽  
Mammalian Cells ◽  
Matrix Protein ◽  
Ebola Virus ◽  
Cell Plasma Membrane ◽  
Replication Process ◽  
Cell Plasma

ABSTRACTLipid-enveloped viruses replicate and bud from the host cell where they acquire their lipid coat. Ebola virus, which buds from the plasma membrane of the host cell, causes viral hemorrhagic fever and has a high fatality rate. To date, little has been known about how budding and egress of Ebola virus are mediated at the plasma membrane. We have found that the lipid phosphatidylserine (PS) regulates the assembly of Ebola virus matrix protein VP40. VP40 binds PS-containing membranes with nanomolar affinity, and binding of PS regulates VP40 localization and oligomerization on the plasma membrane inner leaflet. Further, alteration of PS levels in mammalian cells inhibits assembly and egress of VP40. Notably, interactions of VP40 with the plasma membrane induced exposure of PS on the outer leaflet of the plasma membrane at sites of egress, whereas PS is typically found only on the inner leaflet. Taking the data together, we present a model accounting for the role of plasma membrane PS in assembly of Ebola virus-like particles.IMPORTANCEThe lipid-enveloped Ebola virus causes severe infection with a high mortality rate and currently lacks FDA-approved therapeutics or vaccines. Ebola virus harbors just seven genes in its genome, and there is a critical requirement for acquisition of its lipid envelope from the plasma membrane of the human cell that it infects during the replication process. There is, however, a dearth of information available on the required contents of this envelope for egress and subsequent attachment and entry. Here we demonstrate that plasma membrane phosphatidylserine is critical for Ebola virus budding from the host cell plasma membrane. This report, to our knowledge, is the first to highlight the role of lipids in human cell membranes in the Ebola virus replication cycle and draws a clear link between selective binding and transport of a lipid across the membrane of the human cell and use of that lipid for subsequent viral entry.

scholarly journals Invasion by Toxoplasma gondii Establishes a Moving Junction That Selectively Excludes Host Cell Plasma Membrane Proteins on the Basis of Their Membrane Anchoring

1999 ◽  
Vol 190 (12) ◽  
pp. 1783-1792 ◽  
Author(s):  
Dana G. Mordue ◽  
Naishadh Desai ◽  
Michael Dustin ◽  
L. David Sibley
Keyword(s):  
Plasma Membrane ◽  
Toxoplasma Gondii ◽  
Host Cell ◽  
Transmembrane Domain ◽  
Membrane Lipids ◽  
Transmembrane Proteins ◽  
Host Cells ◽  
Cell Plasma Membrane ◽  
Cell Plasma ◽  
Membrane Anchoring

The protozoan parasite Toxoplasma gondii actively penetrates its host cell by squeezing through a moving junction that forms between the host cell plasma membrane and the parasite. During invasion, this junction selectively controls internalization of host cell plasma membrane components into the parasite-containing vacuole. Membrane lipids flowed past the junction, as shown by the presence of the glycosphingolipid GM1 and the cationic lipid label 1.1′-dihexadecyl-3-3′-3-3′-tetramethylindocarbocyanine (DiIC16). Glycosylphosphatidylinositol (GPI)-anchored surface proteins, such as Sca-1 and CD55, were also readily incorporated into the parasitophorous vacuole (PV). In contrast, host cell transmembrane proteins, including CD44, Na+/K+ ATPase, and β1-integrin, were excluded from the vacuole. To eliminate potential differences in sorting due to the extracellular domains, parasite invasion was examined in host cells transfected with recombinant forms of intercellular adhesion molecule 1 (ICAM-1, CD54) that differed in their mechanism of membrane anchoring. Wild-type ICAM-1, which contains a transmembrane domain, was excluded from the PV, whereas both GPI-anchored ICAM-1 and a mutant of ICAM-1 missing the cytoplasmic tail (ICAM-1–Cyt−) were readily incorporated into the PV membrane. Our results demonstrate that during host cell invasion, Toxoplasma selectively excludes host cell transmembrane proteins at the moving junction by a mechanism that depends on their anchoring in the membrane, thereby creating a nonfusigenic compartment.

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