title: Specificity and valency of concanavalin A in neuron-substratum adhesion and redistribution of cell surface receptors.
abstract: Neurons seeded in culture as spherical cells flatten partially to form lamellipodia by which they adhere to the substratum. Lamellipodium formation is stimulated specifically by concanavalin A (Con A) and other mannose-binding lectins in several types of neuronal cells, but not in similarly treated fibroblasts. Conditions that block much of the adsorption of Con A to the substratum have no effect on stimulation of lamellipodium formation by Con A. This suggests that Con A acts in solution on neurons and does not directly bind them to their substrata. Succinylated-Con A (bivalent) binds to the same receptors as native Con A (tetravalent) but does not elicit lamellipodium extension unless crosslinked with anti-Con A IgG. Treatment of neurons with Con A produces local changes in the composition of the cell surface resulting from redistribution of lectin receptor complexes. This redistribution is not as great with SCon A and, like lamellipodium formation, is sensitive to the valency of Con A. A variety of treatments (4 degrees C, trifluoperazine, nordihydroguaiaretic acid, 4-bromphenacyl bromide, and cytochalasin D), inhibit both Con A-receptor redistribution and lamellipodium extension by neurons. Other treatments (colchicine and cycloheximide) prevented neither lamellipodium formation nor redistribution.
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000276:immunology; D002642:Chick Embryo; D003208:Concanavalin A / Q000378:metabolism / Q000494:pharmacology*; D005727:Ganglia, Spinal / Q000166:cytology / Q000276:immunology; D005728:Ganglia, Sympathetic / Q000166:cytology / Q000276:immunology; D007700:Kinetics; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D011952:Receptors, Concanavalin A / Q000378:metabolism; D013696:Temperature
chemical_list: D011952:Receptors, Concanavalin A; D003208:Concanavalin A