Enzymic dissection of embryonic cell adhesive mechanisms. III. Immunological identification of a component of the calcium-dependent adhesive system of embryonic chick neural retina cells.
Immunological probes and cell-surface biochemical analysis are combined to identify a cell-surface glycoprotein, which appears to be involved in the formation of calcium-dependent adhesions among embryonic chick neural retina cells. Comparison of radioiodinated cells shows that adhesive-competent cells have at their surface two glycoproteins not present on non-adhesive cells. These two components (with Mr 130 x 10(3), pI 4.8 and Mr 70 x 10(3), pI 4.8) are immunoprecipitable with adhesion-blocking antisera. A fraction derived from retina-conditioned medium, containing one major immunoprecipitable component, neutralizes the inhibitory activity of aggregation-inhibiting Fab' fragments and competes in immunoprecipitation for the two glycoprotein components. The evidence suggests that one or both of these components is involved in the formation of calcium-dependent adhesions among embryonic chick neural retina cells.
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002448:Cell Adhesion; D002449:Cell Aggregation; D002642:Chick Embryo; D004586:Electrophoresis; D005136:Eye Proteins / Q000032:analysis / Q000276:immunology; D006023:Glycoproteins / Q000032:analysis* / Q000276:immunology; D007140:Immunoglobulin Fab Fragments; D008565:Membrane Proteins / Q000032:analysis / Q000276:immunology; D012160:Retina / Q000032:analysis / Q000166:cytology / Q000196:embryology*
D005136:Eye Proteins; D006023:Glycoproteins; D007140:Immunoglobulin Fab Fragments; D008565:Membrane Proteins; D002118:Calcium