Phagocytosis in Dictyostelium discoideum is inhibited by antibodies directed primarily against common carbohydrate epitopes of a major cell-surface plasma membrane glycoprotein

1989 ◽  
Vol 181 (1) ◽  
pp. 11-26 ◽  
Author(s):  
Catherine P. Chia ◽  
Elizabeth J. Luna
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Membrane Glycoprotein ◽  
Surface Plasma ◽  
Carbohydrate Epitopes

The Effects of the Chelating Agent Ethylenediamine Tetra-acetic Acid on Cell Adhesion in the Slime Mould Dictyostelium discoideum

Development ◽  
1959 ◽  
Vol 7 (3) ◽  
pp. 335-343
Author(s):  
Robert L. Dehaan
Keyword(s):  
Acetic Acid ◽  
Plasma Membrane ◽  
Cell Adhesion ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Chelating Agent ◽  
Living Cells ◽  
Slime Mould ◽  
Chemical Mechanisms ◽  
Mechanical Separation

Certain properties of living cells appear to depend primarily on changes at, or characteristics of, the cell surface or plasma membrane. Among these ‘surfacelinked’ phenomena are to be classed adhesion of cells to their neighbours or substratum, pseudopodial activity and plasma membrane stability, and, frequently, cell and tissue movements. (Others which might be mentioned, such as pinocytosis, trans-membrane movements of substances, and vacoule formation, will not be considered here.) Attempts to examine these properties in terms of chemical mechanisms have not been notably successful, owing in part to the fact that the experimental material has traditionally been the tissues or embryos of metazoan forms. Thus, investigators have worked with heterogeneous and often constantly changing populations of cells, from which individual cells could be obtained only by the use of more or less deleterious methods such as mechanical separation or treatment with disaggregating agents.

Aβ starts to deposit on cell surface plasma membrane in diffuse plaques

2000 ◽  
Vol 21 ◽  
pp. 56
Author(s):  
Haruyasu Yamaguchi ◽  
Marion L.C. Maat-Schieman ◽  
Sjoerd G. van Duinen ◽  
Remco Natte ◽  
Frans A. Prins ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Surface Plasma ◽  
Diffuse Plaques

Interaction between intracellular vacuoles and the cell surface analysed by finite aperture theory interference reflection microscopy

1982 ◽  
Vol 54 (1) ◽  
pp. 287-298
Author(s):  
D. Gingell ◽  
I. Todd ◽  
N. Owens
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Surface Membrane ◽  
Contractile Vacuole ◽  
Contractile Mechanism ◽  
Cell Surface Membrane ◽  
Minimal Thickness ◽  
Finite Aperture ◽  
Mechanical Consequence

Using finite aperture theory we have shown that localized very dark areas in the interference reflection images of Dictyostelium discoideum amoebae are due to the close intracellular approach of vesicles and tubular elements of the contractile vacuole system to the plasma membrane adjacent to the substratum. Vesicles interacting in this way become locally deformed to the planar contour of the substratum and are separated from the cell surface membrane by a constant approximately less than 0.1 micron of cytoplasm. Lamellar processes formed by these cells on very adhesive surfaces have identical dimensions. This minimal thickness may be a mechanical consequence of a contractile mechanism which pulls membranes together.

Cell surface localization of 5′AMP nucleotidase in prestalk cells of Dictyostelium discoideum

1980 ◽  
Vol 45 (1) ◽  
pp. 119-129
Author(s):  
D.R. Armant ◽  
D.A. Stetler ◽  
C.L. Rutherford
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Model System ◽  
Nucleotidase Activity ◽  
Stage Of Development ◽  
Surface Localization ◽  
Cell Surface Localization ◽  
Enzyme Functions ◽  
Product Accumulation

5′AMP nucleotidase activity was localized by electron microscopy in Dictyostelium discoideum during cell differentiation. In addition, the activity was assayed by micro enzymic methods in sections dissected from specific cellular regions of lyophilized individuals. The results of the 2 procedures were in agreement, demonstrating that at the culmination stage of development the activity is strikingly localized in the prestalk cells adjacent to the prespore region. The cytochemically stained reaction product appeared only along the plasma membrane of the cells. As prestalk cells migrate into the stalk sheath and undergo differentiation, the activity is rapidly lost. Examination of stained cells at high magnification revealed the product accumulation to be primarily at the cell surface, suggesting that the enzyme functions extracellularly. Occasionally, cells having the morphological appearance of prestalk cells were found within the prespore region. These cells demonstrated 5′AMP nucleotidase activity at their plasma membrane in sharp contrast with neighbouring prespore cells. The strategic localization of 5′AMP nucleotidase may reflect a mechanism for establishing and maintaining regulatory levels of extracellular 5′AMP and/or adenosine during pattern formation in this model system.

scholarly journals Sorting of an apical plasma membrane glycoprotein occurs before it reaches the cell surface in cultured epithelial cells.

1984 ◽  
Vol 99 (6) ◽  
pp. 2131-2139 ◽  
Author(s):  
K S Matlin ◽  
K Simons
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Mdck Cells ◽  
Apical Plasma Membrane ◽  
Epithelial Cell Line ◽  
Membrane Glycoprotein ◽  
Apical Surface ◽  
Infected Cells ◽  
Surface Domains ◽  
Darby Canine Kidney

In Madin-Darby canine kidney (MDCK) cells (a polarized epithelial cell line) infected with influenza virus, the hemagglutinin behaves as an apical plasma membrane glycoprotein. To determine biochemically the domain on the plasma membrane, apical or basolateral, where newly synthesized hemagglutinin first appears, cells were cultured on Millipore filters to make both cell surface domains independently accessible. Hemagglutinin in virus-infected cells was pulse-labeled, chased, and detected on the plasma membrane with a sensitive trypsin assay. Under all conditions tested, newly made hemagglutinin appeared simultaneously on both domains, with the bulk found in the apical membrane. When trypsin was continuously present on the basolateral surface during the chase, little hemagglutinin was cleaved relative to the amount transported apically. In addition, specific antibodies against the hemagglutinin placed basolaterally had no effect on transport to the apical domain. These observations suggested that most newly synthesized hemagglutinin does not transiently appear on the basolateral surface but rather is delivered directly to the apical surface in amounts that account for its final polarized distribution.

scholarly journals Inhibition of Caveolae Contributes to Propofol Preconditioning-Suppressed Microvesicles Release and Cell Injury by Hypoxia-Reoxygenation

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Fan Deng ◽  
Shuang Wang ◽  
Shuyun Cai ◽  
Zhe Hu ◽  
Riping Xu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Plasma Membrane ◽  
Endothelial Cell ◽  
Cell Surface ◽  
Protective Effect ◽  
Cell Injury ◽  
Cellular Damage ◽  
Structural Protein ◽  
Surface Plasma ◽  
Antioxidative Stress

Endothelial microvesicles (EMVs), released after endothelial cell (EC) apoptosis or activation, may carry many adverse signals and propagate injury by intercellular transmission. Caveolae are 50–100 nm cell surface plasma membrane invaginations involved in many pathophysiological processes. Recent evidence has indicated EMVs and caveolae may have functional effects in cells undergoing H/R injury. Propofol, a widely used anaesthetic, confers antioxidative stress capability in the same process. But the connection between EMVs, H/R, and caveolae remains largely unclear. Here, we found that H/R significantly increased the release of EMVs, the expression of CAV-1 (the structural protein responsible for maintaining the shape of caveolae), oxidative stress, and the mitochondrial damage, and all these changes were inhibited by propofol preconditioning. Interestingly, the caveolae inhibitor Mβ-CD strengthened the protective effect of propofol preconditioning. We further found that the release of EMVs is more significantly reduced under propofol preconditioning in the presence of the caveolae inhibitor Mβ-CD. EMVs released from H/R-treated cells caused a substantially increased mitochondrial and cellular damage to normal HUVECs after 4 hours of coculture. Thus, we conclude that inhibition of caveolae contributes to propofol preconditioning-suppressed microvesicles release and cell injury by H/R.

scholarly journals A cell surface integral membrane glycoprotein of 85,000 mol wt (gp85) associated with triton X-100-insoluble cell skeleton.

1984 ◽  
Vol 99 (2) ◽  
pp. 512-519 ◽  
Author(s):  
G Tarone ◽  
R Ferracini ◽  
G Galetto ◽  
P Comoglio
Keyword(s):  
Monoclonal Antibody ◽  
Extracellular Matrix ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Membrane Glycoprotein ◽  
Surface Integral ◽  
Intact Cells ◽  
Bhk Cells ◽  
Triton X ◽  
Cell Skeleton

The Triton X-100-insoluble skeleton of baby hamster kidney BHK cells consists of the nucleus, intermediate-size filaments, and actin fibers. By transmission electron microscopy, membrane fragments were found to be associated with these insoluble structures. When radioiodinated or [3H]glucosamine-labeled cells were extracted with 0.5% Triton, most plasma membrane glycoproteins were solubilized except for a glycoprotein with a molecular weight of 85,000 (gp85) that remained associated with the insoluble skeletons. Immunoprecipitation with a specific antiserum indicated that the gp85 is not a proteolytic degradation product of fibronectin, an extracellular matrix glycoprotein insoluble in detergent. A monoclonal antibody of BHK cells specific for gp85 was produced. Immunofluorescence analysis with this monoclonal antibody indicated that gp85 is not associated with the extracellular matrix, but is confined to the cell membrane. Both in fixed and unfixed intact cells, fluorescence was concentrated in dots preferentially aligned in streaks on the cell surface. Gp85 was found to behave as an integral membrane protein interacting with the hydrophobic core of the lipid bilayer since it was extracted from membrane preparations by ionic detergents such as SDS, but not by 0.1 N NaOH (pH 12) in the absence of detergents, a condition known to release peripheral molecules. Association of gp85 with the cell skeleton was unaffected by increasing the Triton concentration up to 5%, but it was affected when actin filaments were dissociated or when a protein-denaturing agent (6 M urea) was used in the presence of Triton, suggesting that protein-protein interactions are involved in the association of gp85 with the cell skeleton. We conclude that gp85 is an integral plasma membrane glycoprotein that might have a role in cell surface-cytoskeleton interaction.

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