Fig. 3. Role of S785 in cell spreading. F9 and GD25 cell lines were assayed for their ability to spread on laminin coated substrates. All F9 cell lines are able to spread on laminin in the absence of the ß1 specific antibody CD29 HA2/5 (A). In the presence of the antibody, untransfected F9 and F9-S785D fail to spread. By contrast, F9-S785S and F9-S785M cells are able to spread (A). Spreading of F9-S785S cells is inhibited if cells are incubated with both anti-chicken-ß1 (W1B10) and anti-mouse-ß1 antibodies (CD29 HA2/5) (B). Untransfected GD25 cells and GD25-S785D2 cells are unable to spread on laminin. Cells expressing either wild-type mouse ß1 or S785S, S785A or S785M spread on laminin (C).