Figure 8.

PDGF-induced Ras activation stimulates motility of Ras-GAP mutant cells. Wild-type cells (A and A′), Ras-GAP mutant cells (B and B′) and Ras-GAP mutant cells stably expressing GAP-N (C and C′), migrate into the denuded zone (A′–C′) more efficiently after PDGF stimulation than unstimulated cells (A–C). Ras activation after wounding and PDGF stimulation at the indicated times was visualized in wild-type cells (d–f and d′–f′) and in Ras-GAP mutant cells (g–i and g′–i′) by labeling with GST-Raf-RBD fusion protein followed by anti-GST antibodies (d–f and g–i). Cultures were also double-labeled for activated MAP kinase using antibodies to phosphorylated ERK1 and 2. Bars: (A–C′) 100 μm; (d–i′) 100 μm.