Figure 5. Functional effect of the CC domain of ERK2.

(a) HeLa cells were transfected with pcDNA3 or FLAG–ERK2(del CC) for 24 h and resuspended in DMEM with 0.5 µg/ml trypsin inhibitor. Cells were washed three times and seeded on to fibronectin coated-dishes (10 µg/ml) and cell spreading was measured at 10 min. Cells were fixed with 4% formaldehyde. Then, 100 attached cells were randomly selected to measure the cell area using ImageJ software (*P<0.01; mean±S.E.M.; n=6). The cell area for pcDNA3 was arbitrarily set to 100. (b) HeLa cells transfected with pcDNA3 or FLAG–ERK2(del CC) for 24 h, were serum-starved for 6 h and then seeded in the upper portion of a Boyden chamber on collagen precoated PVP-free polycarbonate membranes. EGF was added to the lower chamber. Cells were incubated for 6 h at 37 °C in a 5% CO₂ humidified incubator. The membranes were removed and cells were stained. The relative increases in cell density were determined by quantitative densitometry (*P<0.01; mean±S.E.M.; n=6).