Studies on the function of cell surface glycoproteins. I. Use of antisera to surface membranes in the identification of membrane components relevant to cell-substrate adhesion.
An antiserum prepared against purified surface membranes of transformed BHK21/C13 cells (C13/B4) reversibly rounded and detached hamster cells from plastic tissue culture plates but did not affect cells of other species. Antiserum treatment did not alter the growth rate of C13/B4 or BHK21/C13 cells; however, NIL-8 cells exposed to the antiserum detached from the substrate and stopped growing, but remained viable for up to 72 h in the presence of the antiserum. Rounding and detachment were not inhibited by DNP or cycloheximide. Antiserum-detached cells did not reattach in the presence of these inhibitors. F(ab)' fragments also induced rounding, thus ruling out the involvement of complement and ligand-induced rearrangement of surface antigens in rounding and detachment. Three different surface-reactive immunoglobulin preparations were used in indirect immunoprecipitation studies in an attempt to identify cell surface antigens involved in regulating adhesion and morphology. Antiserum against surface membranes (anti-M) and against material shed by the cells into serum-free medium (anti-SFM) caused rounding and detachment, but a third antiserum (anti-LIS) prepared against a partially purified glycoprotein did not. All three immunoglobulin preparations precipitated glycoproteins with an apparent mol wt of 120,000 daltons from a crude membrane preparation solubilized by Nonidet NP-40. The two immunoglobulin preparations that caused rounding precipitated an additional glycoprotein peak of 140,000 daltons. Extensive preabsorption of the extract with anti-LIS immunoglobulin enriched the anti-membrane and antiserum-free medium precipitates for the 140,000-dalton peak. Anti-M immunoglobulin eluted from intact cells and subsequently used to precipitate NP-40 solubilized membrane constituents also reacted with a group of glycoproteins of approximately 140,000 mol wt. Therefore, this group of glycoproteins was considered most likely to be the glycoproteins involved in substrate adhesion and maintenance of cellular morphology.
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis*; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology*; D002471:Cell Transformation, Neoplastic; D006224:Cricetinae; D005347:Fibroblasts / Q000276:immunology*; D006023:Glycoproteins / Q000276:immunology*; D007106:Immune Sera / Q000494:pharmacology; D007668:Kidney; D008565:Membrane Proteins / Q000276:immunology*; D009363:Neoplasm Proteins / Q000276:immunology*; D013045:Species Specificity
D000954:Antigens, Surface; D006023:Glycoproteins; D007106:Immune Sera; D008565:Membrane Proteins; D009363:Neoplasm Proteins