Fig. 8. Kinetic analysis of phosphorylation of DDR1 receptors. (A) Control cells grown on collagen for various periods of time. The cells were lysed and immunoprecipitated with an anti-DDR1 antibody, and the tyrosine phosphorylation status of the DDR1 receptors was determined by immunoblotting with an anti-tyrosine antibody (4G10). (B) DDR1 phosphorylation during the indicated periods of time. The values represent the mean and standard deviation of determinations done on triplicate wells assayed in parallel.