Target cell surface glycoconjugates and neural induction in an amphibian

Development ◽  
1985 ◽  
Vol 86 (1) ◽  
pp. 39-51
Author(s):  
Lydie Gualandris ◽  
Pierre Rouge ◽  
Anne-Marie Duprat
Keyword(s):  
Cell Surface ◽  
Binding Sites ◽  
Neural Induction ◽  
Specific Receptor ◽  
Con A ◽  
Neural Signal ◽  
Electrophysiological Properties ◽  
Ionic Fluxes ◽  
Target Membrane ◽  
Cell Surface Glycoconjugates

The possible involvement of target membrane specific receptor(s) in the transmission of the neural signal leading to activation of the intracellular machinery involved in the process of neural determination, has been examined using lectin probes (Con A, succinylated-ConA, LcA, PsA and SBA). Not only Con A binding sites but many different glycoconjugated molecules (α-Dgalactose, N-acetyl-D-galactosamine, α-D-fucose, N-acetyl-D-glucosamine, etc.) would have to be involved, if neural receptor(s) are invoked to explain initiation of neural induction. We show here that the close involvement of such receptor molecules in neural induction is so far hypothetical and remains to be demonstrated. Moreover we are inclined to the view of Barth and others who suggested that ionic fluxes and physicochemical and electrophysiological properties of the target membrane could play a crucial role in neural induction.

Trypanosoma cruzi: cell surface dynamics in trypomastigotes of different strains

Parasitology ◽  
2019 ◽  
Vol 147 (3) ◽  
pp. 310-321
Author(s):  
Roberta Ferreira Cura das Neves ◽  
Camila Marques Adade ◽  
Anne Cristine Silva Fernandes ◽  
Angela Hampshire Lopes ◽  
Thaïs Souto-Padrón
Keyword(s):  
Cell Surface ◽  
Trypanosoma Cruzi ◽  
Binding Sites ◽  
Host Cells ◽  
Cationized Ferritin ◽  
Surface Dynamics ◽  
Con A ◽  
Low Intensity ◽  
Intense Labelling ◽  
Different Strains

AbstractCapping and shedding of ectodomains in Trypanosoma cruzi may be triggered by different ligands. Here, we analysed the mobility and shedding of cell surface components of living trypomastigotes of the Y strain and the CL Brener clone in the presence of poly-L-lysine, cationized ferritin (CF) and Concanavalin A (Con A). Poly-L-lysine and CF caused intense shedding in Y strain parasites. Shedding was less intense in CL Brener trypomastigotes, and approximately 10% of these parasites did not show any decrease in poly L-lysine or CF labelling. Binding of Con A induced low-intensity shedding in Y strain and redistribution of Con A-binding sites in CL Brener parasites. Trypomastigotes of the Y strain showed intense labelling with anti-〈-galactosyl antibodies, resulting in the lysis of approximately 30% of their population, in contrast with what was observed in CL Brener parasites. Incubation with Con A and CF protected trypomastigotes of the Y strain from lysis by anti-αGal. The last treatment did not interfere with the survival of the CL Brener parasites. This study corroborates with the idea that a ligand can differentially modulate the cell surface of T. cruzi, depending on the strain used, resulting in variable immune system responses and recognition by host cells.

scholarly journals Distribution of concanavalin A binding sites on the surface of dissociated rat submandibular gland acinar cells.

1975 ◽  
Vol 23 (8) ◽  
pp. 607-617 ◽  
Author(s):  
T Amakawa ◽  
T Barka
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Surface ◽  
Concanavalin A ◽  
Binding Sites ◽  
Lectin Binding ◽  
Single Cells ◽  
Apical Cell ◽  
Acinar Cells ◽  
Con A ◽  
Dissociated Cells

The submandibular glands of 4-week-old rats were dissociated by a procedure involving digestions with collagenase and hyaluronidase, chelation of divalent cations and mechanical force. A suspension of single cells was obtained in low yield by centrifugation in a Ficoll-containing medium. Immediately after dissociation and after a culture period of 16-18 hr the dissociated cells were tested for agglutinability by concanavalin A (Con A). Using ferritin (tfer)-conjugated Con A the lectin binding by the isolated acinar cells was also studied. The dissociated cells were agglutinated by low concentrations of Con A and bound Fer-Con A molecules on their entire surface without any indication of polarization of the cell membrane. There was a considerable cell to cell variation in the amount of Fer-Con A binding which was, in general, sparse and patchy. The contact surfaces between agglutinated cells revealed a dense binding of Fer-Con A molecules irrespective of the types of cells participating in the agglutination reaction. Cells cultured for 16-18 hr were no longer agglutinated by Con A. As compared to the freshly dissociated cells the cultured acinar cells revealed a more uniform and denser binding of Fer-Con A molecules. Furthermore, there were more lectin molecules bound to the cell surface corresponding to the basal part of the cell, where the nucleus and most of the rough surface endoplasmic reticulum were located, than to the apical cell surface. It is suggested that the higher density of lectin-binding sites on the cell surface in the vicinity of the cisternae of the rough endoplasmic reticulum indicates insertion sites of newly synthesized membrane glycoproteins.

scholarly journals Reversibility of cell surface label rearrangement.

1976 ◽  
Vol 68 (3) ◽  
pp. 629-641 ◽  
Author(s):  
S S Brown ◽  
J P Revel
Keyword(s):  
Electron Microscopy ◽  
Cell Surface ◽  
Binding Sites ◽  
Random Distribution ◽  
Cytochalasin B ◽  
Con A ◽  
Original Distribution ◽  
Sensitive Structure ◽  
Membrane Components ◽  
Scanning Electron

Cell surface labeling can cause rearrangements of randomly distributed membrane components. Removal of the label bound to the cell surface allows the membrane components to return to their original random distribution, demonstrating that label is necessary to maintain as well as to induce rearrangements. With scanning electron microscopy, the rearrangement of concanavalin A (con A) and ricin binding sites on LA-9 cells has been followed by means of hemocyanin, a visual label. The removal of con A from its binding sites at the cell surface with alpha-methyl mannoside, and the return of these sites to their original distribution are also followed in this manner. There are labeling differences with con A and ricin. Under some conditions, however, the same rearrangements are seen with both lectins. The disappearance of labeled sites from areas of ruffling activity is a major feature of the rearrangements seen. Both this ruffling activity and the rearrangement of label are sensitive to cytochalasin B, and ruffling activity, perhaps along with other cytochalasin-sensitive structure, may play a role in the rearrangements of labeled sites.

scholarly journals Membrane structure and surface coat of Entamoeba histolytica. Topochemistry and dynamics of the cell surface: cap formation and microexudate.

1975 ◽  
Vol 64 (3) ◽  
pp. 538-550 ◽  
Author(s):  
P P Silva ◽  
A Martínez-Palomo ◽  
A Gonzalez-Robles
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Binding Sites ◽  
Membrane Structure ◽  
Ruthenium Red ◽  
Iron Binding ◽  
Con A ◽  
Colloidal Iron ◽  
Acidic Sites ◽  
Membrane Components

Treatment of living entamoeba histolytica cells with low concentrations of concanavalin A (con A) and peroxidase results in redistribution of the plasma membrane con A receptors to one pole of the cell where a morphologically distinct region--the uroid--is formed. Capping of con A receptors is not accompanied by parallel accumulation of ruthenium red-stainable components. In capped cells, the pattern of distribution of acidic sites ionized at pH 1.8 (labeled by colloidal iron) at the outer surface and of membrane particles (integral membrane components revealed by freeze-fracture) is not altered over the uroid region. Cytochemistry of substrate-attached microexudate located in regions adjacent to E. histolytica cells demonstrates the presence of con A binding sites and ruthenium red- and alcian blue-stainable components and the absent of colloidal iron binding sites. In a previous report we demonstrated that glycerol-induced aggregation of the plasma membrane particles is accompanied by a discontinuous distribution of colloidal iron binding sites, while con A receptors and acidic sites ionized at pH 4.0 remain uniformly distributed over the cell surface. Taken together, our experiments show that, in E. histolytica cells, peripheral membrane components may move independently of integral components and, also, that certain surface determinants may redistribute independently of others. These results point to the complexity of the membrane structure-cell surface relationship in E. histolytica plasma membranes relative to the membrane of the erythrocyte ghost where integral components (the membrane-intercalated particles) contain all antigens, receptors, and anionic sites labeled so far. We conclude that fluidity of integral membrane components (integral membrane fluidity) cannot be inferred from the demonstration of the mobility of surface components nor, conversely, can the fluidity of peripheral membrane components (peripheral membrane fluidity) be assumed from demonstration of the mobility of integral membrane components.

Cell Agglutination Mediated by Concanavalin A and the Dynamic State of the Cell Surface

1974 ◽  
Vol 14 (1) ◽  
pp. 197-202
Author(s):  
M. INOUE
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Binding Sites ◽  
Dynamic Condition ◽  
Dynamic State ◽  
Con A ◽  
Cell Agglutination ◽  
Surface Receptors ◽  
Topographical Distribution ◽  
Ehrlich Ascites Tumour

The binding of 131I-labelled concanavalin A (131I-Con A) to the cell surface has been studied in Ehrlich ascites tumour cells (EATC) and beef erythrocytes under various conditions. The binding of concanavalin A (Con A) to the cell surface was very specific and the available binding sites were saturated within a few minutes. The amount of 131I-Con A bound to EATC was 4.14 x 107 molecules/cell at 37 °C and 2.12 x 107 molecules/cell at 0 °C. Under these conditions, cell agglutination was observed only at 37 °C and not at 0 °C. However, the binding sites measured at 0 °C were also effective for agglutination at 37 °C. Beef erythrocytes were agglutinated by Con A only after treatment of cells with papain. The number of binding sites for Con A on the cell surface was decreased by this treatment to about half the number present on untreated cells. Various reagents such as colchicine, monoiodoacetic acid, dinitrophenol, rotenone, sodium azide and carboxyl cyanide-m-fluorophenylhydrazone (FCCP) had no effect on Con A-mediated cell agglutination. In contrast, periodate treatment produced a remarkable decrease in the agglutinability of cells. From these data, it is concluded that the cell agglutination induced by Con A was due to the topographical distribution of the surface receptors for the lectin, and not the result of energy-dependent or microtubule-dependent reaction processes. The number and the state of Con A receptors on the cell surface were in a dynamic condition, their conformation, orientation, and/or topographical distribution changing under different conditions.

Utilization of replicas to show gold-probe binding to sperm cells for SEM and TEM

1987 ◽  
Vol 45 ◽  
pp. 958-959
Author(s):  
C. J. Battjes ◽  
J. L. Adams ◽  
D. A. Buthala
Keyword(s):  
Cell Surface ◽  
Binding Sites ◽  
Three Dimensional ◽  
Ultrastructural Level ◽  
Surface Binding ◽  
Con A ◽  
Gold Particles ◽  
Glass Slides ◽  
Thin Sectioning ◽  
Gold Probe

The introduction of gold particles bound to various probes has facilitated studies of cell surface and intracellular tracing. One problem has been the inability to show surface binding of small gold particles without embedding and thin-sectioning the sample. Our work has shown that small gold probes of 10-15 nm diameter attached to lectins can be detected at surface sites by the use of replicas. The replica retains the three-dimensional aspect of the cell surface while fixing the gold-probe in place. Murine spermatazoa labelled with gold-Con A were replicated directly or replicated following a silver intensification. Results showed that the probes remained at their binding sites and were clearly visible at the ultrastructural level.Murine epididymal and caudal sperm were collected in PBS pH=7.4. Sperm were sedimented twice through PBS, then spread onto clean glass slides and fixed with 3% glutaraldehyde in Millonig's buffer.

scholarly journals Double labeling study of anionic sites and concanavalin A binding sites in monkey macrophages.

1981 ◽  
Vol 29 (7) ◽  
pp. 858-863 ◽  
Author(s):  
K Takata ◽  
F Nishiyama ◽  
H Hirano
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Binding Sites ◽  
Peritoneal Macrophages ◽  
Independent Mobility ◽  
Anionic Sites ◽  
Con A ◽  
Double Labeling ◽  
Double Technique ◽  
Hrp Method

Cationized ferritin (CF) binding, and its effect on the concanavalin A (Con A) binding pattern were studied by the double technique in monkey peritoneal macrophages. CF particles formed clumps and were internalized when cells were incubated at 37 degrees C. Such cells were fixed, and the Con A binding sites were visualized by the Con A-horseradish peroxidase (HRP) method. Using the same specimen, the distribution of CF particles and the Con A-HRP product was observed under an electron microscope. The redistribution and internalization of CF particles did not affect the continuous label of the cell surface Con A binding sites. These observations suggest the independent mobility of cell surface anionic sites and Con A binding sites.

Lectin Binding Studies on RNA Tumor Virus-Infected Cells

1975 ◽  
Vol 33 ◽  
pp. 326-327
Author(s):  
D. C. Hixson
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Culture Conditions ◽  
3T3 Cells ◽  
Binding Studies ◽  
Con A ◽  
Microscopic Studies ◽  
Tumor Virus ◽  
Infected Cells ◽  
Cell Culture Conditions

The abilities of plant lectins to preferentially agglutinate malignant cells and to bind to specific monosaccharide or oligosaccharide sequences of glycoproteins and glycolipids make them a new and important biochemical probe for investigating alterations in plasma membrane structure which may result from malignant transformation. Electron and light microscopic studies have demonstrated clustered binding sites on surfaces of SV40-infected or tryp- sinized 3T3 cells when labeled with concanavalin A (con A). No clustering of con A binding sites was observed in normal 3T3 cells. It has been proposed that topological rearrangement of lectin binding sites into clusters enables con A to agglutinate SV40-infected or trypsinized 3T3 cells (1). However, observations by other investigators have not been consistent with this proposal (2) perhaps due to differences in reagents used, cell culture conditions, or labeling techniques. The present work was undertaken to study the lectin binding properties of normal and RNA tumor virus-infected cells and their associated viruses using lectins and ferritin-conjugated lectins of five different specificities.

scholarly journals The preendosomal compartment comprises distinct coated and noncoated endocytic vesicle populations.

1991 ◽  
Vol 113 (4) ◽  
pp. 731-741 ◽  
Author(s):  
S H Hansen ◽  
K Sandvig ◽  
B van Deurs
Keyword(s):  
Cell Surface ◽  
Coated Vesicles ◽  
Minor Role ◽  
Specific Marker ◽  
Con A ◽  
Early Endosomes ◽  
Gold Conjugate ◽  
Entire Cell ◽  
A Minor ◽  
Endocytic Vesicles

The transfer of molecules from the cell surface to the early endosomes is mediated by preendosomal vesicles. These vesicles, which have pinched off completely from the plasma membrane but not yet fused with endosomes, form the earliest compartment along the endocytic route. Using a new assay to distinguish between free and cell surface connected vesicle profiles, we have characterized the preedosomal compartment ultrastructurally. Our basic experimental setup was labeling of the entire cell surface at 4 degrees C with Con A-gold, warming of the cells to 37 degrees C to allow endocytosis, followed by replacing incubation medium with fixative, all within either 30 or 60 s. Then the fixed cells were incubated with anti-Con A-HRP to distinguish truly free (gold labeled) endocytic vesicles from surface-connected structures. Finally, analysis of thin (20-30 nm) serial sections and quantification of vesicle diameters were carried out. Based on this approach it is shown that the preendosomal compartment comprises both clathrin-coated and non-coated endocytic vesicles with approximately the same frequency but with distinct diameter distributions, the average noncoated vesicle being smaller (95 nm) than the average coated one (110 nm). In parallel experiments, using an anti-transferrin receptor gold-conjugate as a specific marker for clathrin-dependent endocytosis it is also shown that uncoating of coated vesicles plays only a minor role for the total frequency of noncoated vesicles. Furthermore, after perturbation of clathrin-dependent endocytosis by potassium depletion where uptake of transferrin is blocked, noncoated endocytic vesicles with Con A-gold, but not coated vesicles, exist already after 30 and 60 s. Finally, it is shown that the existence of small, free vesicles in the short-time experiments cannot be ascribed to recycling from the early endosomes.

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