title: Interactions of lectins with CHO cell surface membranes. II. Differential effects of local anesthetics on endocytosis of Con A and WGA binding sites.
abstract: Using fibroblastic CHO cells, we have examined 1) the internalization and redistribution of surface binding sites for the lectins Concanavalin A and wheat germ agglutinin and 2) the sensitivity of these processes to putative inhibitors of cytoskeletal activity. Following initial exposure to fluorescein conjugated Con A (CAF) or WGA (WGAF) at 4 degrees C, kinetic analysis of internalization and intracellular aggregation of lectin at 37 degrees C indicated more rapid aggregate formation in the case of WGA than in the case of Con A. Treatment with tertiary amine local anesthetics (tetracaine, dibucaine, and xylocaine) or with a lysosomatrophic amine, m-dansyl cadaverine, blocked internalization of Con A but not of WGA. Similar differential effects on redistribution of Con A and WGA were not however observed with the antimicrotubule agents colchicine and nocodazole. Simultaneous treatment of cells with WGAF and with rhodamine labeled Con A (CAR) resulted in the accumulation of both labels in a central perinuclear aggregate; a similar experiment in the presence of local anesthetic resulted in a diffuse peripheral distribution of CAR and a central aggregate of WGAF. These results suggest 1) CHO cells possess at least two distinct pathways for lectin internalization and redistribution, which can be discriminated in terms of drug sensitivity; 2) CHO cells can sort out and independently internalize different populations of lectin binding sites; and 3) different pathways may be a manifestation of biochemically distinct linkages between cytoskeletal elements and various groups of surface glycoproteins. Present findings concur with our previous results concerning the mutual independence of the surface binding sites for Con A and WGA (Emerson and Juliano, 1982).
mesh_terms: D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000276:immunology; D006224:Cricetinae; D003412:Cricetulus; D004705:Endocytosis / Q000187:drug effects*; D005260:Female; D005455:Fluorescent Antibody Technique; D007700:Kinetics; D037102:Lectins; D010053:Ovary; D011952:Receptors, Concanavalin A / Q000187:drug effects / Q000378:metabolism*; D011975:Receptors, Mitogen / Q000187:drug effects / Q000378:metabolism*; D014909:Wheat Germ Agglutinins
chemical_list: D000779:Anesthetics, Local; D037102:Lectins; D011952:Receptors, Concanavalin A; D011975:Receptors, Mitogen; D014909:Wheat Germ Agglutinins; C027503:wheat germ agglutinin receptor