title: Molecular nature of the calcium-dependent cell-cell adhesion system in mouse teratocarcinoma and embryonic cells studied with a monoclonal antibody.
abstract: The molecular nature of the Ca2+-dependent cell-cell adhesion system in mouse teratocarcinoma (t-CDS) was studied using a monoclonal antibody recognizing t-CDS. We isolated a hybridoma clone producing a monoclonal antibody (ECCD-1) able to disrupt cell-cell adhesion when added to monolayer cultures of teratocarcinoma cells. This antibody bound to the cells with intact t-CDS, resulting in an inhibition of their aggregation, but did not bind to cells from which t-CDS was removed by trypsin treatment in the absence of Ca2+. The binding of ECCD-1 to cell surfaces required Ca2+ but not other ions. Western blot analysis showed that ECCD-1 recognizes multiple cell surface proteins, the major one of which is a component with a molecular weight of 124,000. The binding of ECCD-1 to these antigens was Ca2+-dependent even in cell-free systems, suggesting that the molecules involved in t-CDS undergo conformational changes by binding with Ca2+, leading to conversion of their molecular structure into an active form. ECCD-1 also reacted with 8-cell stage mouse embryos and with certain types of epithelial cells (excluding fibroblastic cells) in various differentiated tissues collected from mouse fetuses, again affecting their cell-cell adhesion. We also showed that a monoclonal antibody (DE1) raised against gp84 (F. Hyafil et al., 1981, Cell 26, 447-454) recognizes the same antigens as ECCD-1.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000276:immunology / Q000502:physiology*; D002118:Calcium / Q000502:physiology*; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules; D002449:Cell Aggregation; D008565:Membrane Proteins / Q000276:immunology / Q000502:physiology*; D051379:Mice / Q000196:embryology*; D013724:Teratoma; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D008565:Membrane Proteins; D002118:Calcium