Figure 9: PD98059 inhibits ERK1/2 activation in a dose-dependent manner. Cells were cultured on the –NH2- and –CH3-modified substrates containing 0, 10, 25, and 50 μM of PD98059 for 10 days. (a) –NH2-modified substrate and (b) –CH3-modified substrate. Cell lysates were analyzed by immunoblots using phospho-ERK-specific and nonactivated ERK1/2 antibodies; GAPDH was used as a control.