Figure 6.

PI3KC2β is localized to lamellipodia in EGF-stimulated A-431 cells. (A) PI3KC2β-expressing cells were incubated for 24 h in a serum-free medium (top) or stimulated with 100 ng/ml EGF for 10 min (bottom). Cells were fixed and stained with phalloidin and anti-Myc antibody to visualize PI3KC2β. (B) A mutant of Eps8 unable to form a complex with Abi1, Eps8ΔSH3, impairs lamellipodia formation in A-431 PI3KC2β-expressing cells. PI3KC2β-expressing cells were transiently transfected with myc-Eps8ΔSH3. After 24 h, cells were fixed and stained with anti-Myc antibody and phalloidin. Lamellipodia, indicated by arrows, were inhibited in roughly 60% of Eps8ΔSH3-expressing cells.