scholarly journals Membrane Trafficking Proteins: A New Target to Identify Resistance to Viruses in Plants

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2139
Author(s):  
Aimeric Agaoua ◽  
Abdelhafid Bendahmane ◽  
Frédéric Moquet ◽  
Catherine Dogimont
Keyword(s):  
Membrane Trafficking ◽  
Virus Resistance ◽  
Viral Proteins ◽  
Published Data ◽  
Vesicle Formation ◽  
Plant Proteins ◽  
Associated Proteins ◽  
Variant Alleles ◽  
Endomembrane Trafficking ◽  
Resistance To Viruses

Replication cycles from most simple-stranded positive RNA viruses infecting plants involve endomembrane deformations. Recent published data revealed several interactions between viral proteins and plant proteins associated with vesicle formation and movement. These plant proteins belong to the COPI/II, SNARE, clathrin and ESCRT endomembrane trafficking mechanisms. In a few cases, variations of these plant proteins leading to virus resistance have been identified. In this review, we summarize all known interactions between these plant cell mechanisms and viruses and highlight strategies allowing fast identification of variant alleles for membrane-associated proteins.

scholarly journals Lava Lamp, a Novel Peripheral Golgi Protein, Is Required for Drosophila melanogaster Cellularization

2000 ◽  
Vol 151 (4) ◽  
pp. 905-918 ◽  
Author(s):  
John C. Sisson ◽  
Christine Field ◽  
Richard Ventura ◽  
Anne Royou ◽  
William Sullivan
Keyword(s):  
Membrane Trafficking ◽  
Biochemical Analysis ◽  
Potent Inhibitor ◽  
Animal Cell ◽  
Coiled Coil ◽  
Brefeldin A ◽  
Microtubule Associated Proteins ◽  
Golgi Bodies ◽  
Associated Proteins ◽  
Golgi Protein

Drosophila cellularization and animal cell cytokinesis rely on the coordinated functions of the microfilament and microtubule cytoskeletal systems. To identify new proteins involved in cellularization and cytokinesis, we have conducted a biochemical screen for microfilament/microtubule-associated proteins (MMAPs). 17 MMAPs were identified; seven have been previously implicated in cellularization and/or cytokinesis, including KLP3A, Anillin, Septins, and Dynamin. We now show that a novel MMAP, Lava Lamp (Lva), is also required for cellularization. Lva is a coiled-coil protein and, unlike other proteins previously implicated in cellularization or cytokinesis, it is Golgi associated. Our functional analysis shows that cellularization is dramatically inhibited upon injecting anti–Lva antibodies (IgG and Fab) into embryos. In addition, we show that brefeldin A, a potent inhibitor of membrane trafficking, also inhibits cellularization. Biochemical analysis demonstrates that Lva physically interacts with the MMAPs Spectrin and CLIP190. We suggest that Lva and Spectrin may form a Golgi-based scaffold that mediates the interaction of Golgi bodies with microtubules and facilitates Golgi-derived membrane secretion required for the formation of furrows during cellularization. Our results are consistent with the idea that animal cell cytokinesis depends on both actomyosin-based contraction and Golgi-derived membrane secretion.

The ClC-3 chloride channel promotes acidification of lysosomes in CHO-K1 and Huh-7 cells

2002 ◽  
Vol 282 (6) ◽  
pp. C1483-C1491 ◽  
Author(s):  
Xinhua Li ◽  
Ting Wang ◽  
Zhifang Zhao ◽  
Steven A. Weinman
Keyword(s):  
Cathepsin D ◽  
Chinese Hamster ◽  
Proton Pumping ◽  
Vesicle Formation ◽  
Channel Activity ◽  
Permeable Membrane ◽  
Considerable Debate ◽  
Associated Proteins ◽  
Intracellular Vesicles ◽  
Intracellular Channel

ClC-3 is a voltage-gated Cl−channel that is highly conserved and widely expressed, although its function, localization, and properties remain a matter of considerable debate. In this study, we have shown that heterologous expression of ClC-3 in either Chinese hamster ovary (CHO-K1) or human hepatoma (Huh-7) cells results in the formation of large, acidic vesicular structures within cells. Vesicle formation is prevented by bafilomycin, an inhibitor of the vacuolar ATPase, and is not induced by an E224A mutant of ClC-3 with altered channel activity. This demonstrates that vesicle formation requires both proton pumping and Cl−channel activity. Manipulation of the intracellular Cl−concentration demonstrated that the ClC-3-associated vesicles shrink and swell consistent with a highly Cl−-permeable membrane. The ClC-3 vesicles were identified as lysosomes based on their colocalization with the lysosome-associated proteins lamp-1, lamp-2, and cathepsin D and on their failure to colocalize with fluorescently labeled endosomes. We conclude that ClC-3 is an intracellular channel that conducts Cl− when it is present in intracellular vesicles. Its overexpression results in its appearance in enlarged lysosome-like structures where it contributes to acidification by charge neutralization.

scholarly journals Hijacking of Lipid Droplets by Hepatitis C, Dengue and Zika Viruses—From Viral Protein Moonlighting to Extracellular Release

2020 ◽  
Vol 21 (21) ◽  
pp. 7901 ◽  
Author(s):  
Alexandra P.M. Cloherty ◽  
Andrea D. Olmstead ◽  
Carla M.S. Ribeiro ◽  
François Jean
Keyword(s):  
Hepatitis C ◽  
Viral Infection ◽  
Host Cell ◽  
Lipid Droplets ◽  
Viral Proteins ◽  
Biological Properties ◽  
Protein Functions ◽  
Associated Proteins ◽  
Viral Lifecycle ◽  
Moonlighting Functions

Hijacking and manipulation of host cell biosynthetic pathways by human enveloped viruses are essential for the viral lifecycle. Flaviviridae members, including hepatitis C, dengue and Zika viruses, extensively manipulate host lipid metabolism, underlining the importance of lipid droplets (LDs) in viral infection. LDs are dynamic cytoplasmic organelles that can act as sequestration platforms for a unique subset of host and viral proteins. Transient recruitment and mobilization of proteins to LDs during viral infection impacts host-cell biological properties, LD functionality and canonical protein functions. Notably, recent studies identified LDs in the nucleus and also identified that LDs are transported extracellularly via an autophagy-mediated mechanism, indicating a novel role for autophagy in Flaviviridae infections. These developments underline an unsuspected diversity and localization of LDs and potential moonlighting functions of LD-associated proteins during infection. This review summarizes recent breakthroughs concerning the LD hijacking activities of hepatitis C, dengue and Zika viruses and potential roles of cytoplasmic, nuclear and extracellular LD-associated viral proteins during infection.

Screening for Down syndrome in the first trimester

1995 ◽  
Vol 7 (6) ◽  
pp. 1413 ◽  
Author(s):  
KJ Powell ◽  
JG Grudzinskas
Keyword(s):  
Down Syndrome ◽  
First Trimester ◽  
Maternal Blood ◽  
Maternal Serum ◽  
Published Data ◽  
Maternal Serum Screening ◽  
Ultrasound Findings ◽  
Serum Screening ◽  
Associated Proteins ◽  
Trimester Screening

Second-trimester maternal serum screening for Down syndrome is now well established, and permits detection of up to 70% of cases. The disadvantage of this sort of screening is that the timing of maternal blood sampling is relatively late (after 15 weeks). There is an accumulating body of evidence to suggest that in the first trimester concentrations of a number of pregnancy-associated proteins and hormones differ in chromosomally normal and abnormal pregnancies. A first-trimester maternal serum screening test for Down syndrome may therefore be possible. In addition, new methods of screening have recently been described based on ultrasound findings at 11 to 13 weeks of gestation. This review article presents a discussion of published data on the feasibility of first-trimester screening for Down syndrome.

scholarly journals Plasma Membrane-Associated Restriction Factors and Their Counteraction by HIV-1 Accessory Proteins

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1020 ◽  
Author(s):  
Ramirez ◽  
Sharma ◽  
Singh ◽  
Stoneham ◽  
Vollbrecht ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Trafficking ◽  
Immune Surveillance ◽  
Viral Envelope ◽  
Accessory Proteins ◽  
Host Defenses ◽  
Restriction Factors ◽  
Associated Proteins ◽  
Infected Cells ◽  
Hiv 1

The plasma membrane is a site of conflict between host defenses and many viruses. One aspect of this conflict is the host’s attempt to eliminate infected cells using innate and adaptive cell-mediated immune mechanisms that recognize features of the plasma membrane characteristic of viral infection. Another is the expression of plasma membrane-associated proteins, so-called restriction factors, which inhibit enveloped virions directly. HIV-1 encodes two countermeasures to these host defenses: The membrane-associated accessory proteins Vpu and Nef. In addition to inhibiting cell-mediated immune-surveillance, Vpu and Nef counteract membrane-associated restriction factors. These include BST-2, which traps newly formed virions at the plasma membrane unless counteracted by Vpu, and SERINC5, which decreases the infectivity of virions unless counteracted by Nef. Here we review key features of these two antiviral proteins, and we review Vpu and Nef, which deplete them from the plasma membrane by co-opting specific cellular proteins and pathways of membrane trafficking and protein-degradation. We also discuss other plasma membrane proteins modulated by HIV-1, particularly CD4, which, if not opposed in infected cells by Vpu and Nef, inhibits viral infectivity and increases the sensitivity of the viral envelope glycoprotein to host immunity.

scholarly journals Arenavirus budding resulting from viral-protein-associated cell membrane curvature

2013 ◽  
Vol 10 (86) ◽  
pp. 20130403 ◽  
Author(s):  
David Schley ◽  
Robert J. Whittaker ◽  
Benjamin W. Neuman
Keyword(s):  
Experimental Data ◽  
Cell Membrane ◽  
Viral Protein ◽  
Viral Proteins ◽  
Membrane Curvature ◽  
Vesicle Formation ◽  
Lipid Layer ◽  
Virus Budding ◽  
Plausible Mechanism ◽  
Membrane Stiffness

Viral replication occurs within cells, with release (and onward infection) primarily achieved through two alternative mechanisms: lysis, in which virions emerge as the infected cell dies and bursts open; or budding, in which virions emerge gradually from a still living cell by appropriating a small part of the cell membrane. Virus budding is a poorly understood process that challenges current models of vesicle formation. Here, a plausible mechanism for arenavirus budding is presented, building on recent evidence that viral proteins embed in the inner lipid layer of the cell membrane. Experimental results confirm that viral protein is associated with increased membrane curvature, whereas a mathematical model is used to show that localized increases in curvature alone are sufficient to generate viral buds. The magnitude of the protein-induced curvature is calculated from the size of the amphipathic region hypothetically removed from the inner membrane as a result of translation, with a change in membrane stiffness estimated from observed differences in virion deformation as a result of protein depletion. Numerical results are based on experimental data and estimates for three arenaviruses, but the mechanisms described are more broadly applicable. The hypothesized mechanism is shown to be sufficient to generate spontaneous budding that matches well both qualitatively and quantitatively with experimental observations.

scholarly journals Forced association of SARS-CoV-2 proteins with the yeast proteome perturb vesicle trafficking

2021 ◽  
Vol 8 (12) ◽  
pp. 280-296
Author(s):  
Cinzia Klemm ◽  
Henry Wood ◽  
Grace Heredge Thomas ◽  
Guðjón Ólafsson ◽  
Mara Teixeira ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Mammalian Cells ◽  
Drug Targets ◽  
Viral Proteins ◽  
Vesicle Docking ◽  
Growth Defects ◽  
Yeast Proteome ◽  
Physical Interactions ◽  
Intermediate Compartment ◽  
Potential Drug Targets

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the highly infectious coronavirus disease COVID-19. Extensive research has been performed in recent months to better understand how SARS-CoV-2 infects and manipulates its host to identify potential drug targets and support patient recovery from COVID-19. However, the function of many SARS-CoV-2 proteins remains uncharacterised. Here we used the Synthetic Physical Interactions (SPI) method to recruit SARS-CoV-2 proteins to most of the budding yeast proteome to identify conserved pathways which are affected by SARS-CoV-2 proteins. The set of yeast proteins that result in growth defects when associated with the viral proteins have homologous functions that overlap those identified in studies performed in mammalian cells. Specifically, we were able to show that recruiting the SARS-CoV-2 NSP1 protein to HOPS, a vesicle-docking complex, is sufficient to perturb membrane trafficking in yeast consistent with the hijacking of the endoplasmic-reticulum–Golgi intermediate compartment trafficking pathway during viral infection of mammalian cells. These data demonstrate that the yeast SPI method is a rapid way to identify potential functions of ectopic viral proteins.

scholarly journals Mapping protein interactions of sodium channel NaV1.7 using epitope-tagged gene targeted mice

2017 ◽  
Author(s):  
Alexandros H. Kanellopoulos ◽  
Jennifer Koenig ◽  
Honglei Huang ◽  
Martina Pyrski ◽  
Queensta Millet ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Protein Interactions ◽  
Membrane Trafficking ◽  
Neurotransmitter Release ◽  
Critical Role ◽  
Pain Mechanisms ◽  
Collapsin Response Mediator Protein ◽  
Pain Pathways ◽  
Mediator Protein ◽  
Associated Proteins

AbstractThe voltage-gated sodium channel NaV1.7 plays a critical role in pain pathways. Besides action potential propagation, NaV1.7 regulates neurotransmitter release, integrates depolarizing inputs over long periods and regulates transcription. In order to better understand these functions, we generated an epitope-tagged NaV1.7 mouse that showed normal pain behavior. Analysis of NaV1.7 complexes affinity-purified under native conditions by mass spectrometry revealed 267 NaV1.7 associated proteins including known interactors, such as the sodium channel β3 subunit (Scn3b) and collapsin response mediator protein (Crmp2), and novel interactors. Selected novel NaV1.7 protein interactors membrane-trafficking protein synapototagmin-2 (Syt2), G protein-regulated inducer of neurite outgrowth 1 (Gprin1), L-type amino acid transporter 1 (Lat1) and transmembrane P24 trafficking protein 10 (Tmed10) together with Scn3b and Crmp2 were validated using co-immunoprecipitation and functional assays. The information provided with this physiologically normal epitope-tagged mouse should provide useful insights into the pain mechanisms associated with NaV1.7 channel function.

scholarly journals Phosphoinositides in Retinal Function and Disease

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 866 ◽  
Author(s):  
Theodore G. Wensel
Keyword(s):  
Membrane Trafficking ◽  
New Technologies ◽  
Second Messengers ◽  
Regulatory Pathways ◽  
Peripheral Membrane Proteins ◽  
New Information ◽  
Mammalian Retina ◽  
Pigmented Epithelium ◽  
Associated Proteins ◽  
And Control

Phosphatidylinositol and its phosphorylated derivatives, the phosphoinositides, play many important roles in all eukaryotic cells. These include modulation of physical properties of membranes, activation or inhibition of membrane-associated proteins, recruitment of peripheral membrane proteins that act as effectors, and control of membrane trafficking. They also serve as precursors for important second messengers, inositol (1,4,5) trisphosphate and diacylglycerol. Animal models and human diseases involving defects in phosphoinositide regulatory pathways have revealed their importance for function in the mammalian retina and retinal pigmented epithelium. New technologies for localizing, measuring and genetically manipulating them are revealing new information about their importance for the function and health of the vertebrate retina.

GGA proteins: new players in the sorting game

2001 ◽  
Vol 114 (19) ◽  
pp. 3413-3418 ◽  
Author(s):  
Annette L. Boman
Keyword(s):  
Membrane Trafficking ◽  
Sequence Homology ◽  
Mammalian Cells ◽  
Gene Knockout ◽  
Protein Domains ◽  
Vesicle Formation ◽  
Trans Golgi Network ◽  
And Function ◽  
Golgi Network ◽  
Cargo Sorting

The GGA proteins are a novel family of proteins that were discovered nearly simultaneously by several labs studying very different aspects of membrane trafficking. Since then, several studies have described the GGA proteins and their functions in yeast and mammalian cells. Four protein domains are present in all GGA proteins, as defined by sequence homology and function. These different domains interact directly with ARF proteins, cargo and clathrin. Alteration of the levels of GGA proteins by gene knockout or overexpression affects specific trafficking events between the trans-Golgi network and endosomes. These data suggest that GGAs function as ARF-dependent, monomeric clathrin adaptors to facilitate cargo sorting and vesicle formation at the trans-Golgi network.

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