FIGURE 7:

DIF-1–regulated phosphorylation sites in ERK2 and its substrate EppA. (A) Temporal profile for DIF-1–induced phosphorylation changes in class I sites on ERK2 (DDB0191457) and EppA (DDB0233660). Solid lines represent averaged data for class I sites and dashed lines from class III sites from a single experiment. (B) ERK2 T176/Y178 phosphorylation in response to DIF-1. Ax2 cells starved for 5 h in KK2 were treated with 5 mM caffeine (10 min) and then washed out before cells (1 × 10⁷ cells/ml) were treated with 1 μM cAMP for 2 min before addition of 100 nM DIF-1. Samples were collected at the times indicated and then immunoblotted using anti–phospho p44/42 MAPK antibody. Blots were stripped and reprobed with anti-actin antibody as a loading control. Results are representative of at least three independent experiments.