SH3BP1 regulates EGF-induced dorsal ruffling and junction formation. (A) A431 cells were serum starved and then stimulated with EGF as indicated. Cells were then fixed, stained, and analyzed by epifluorescence. For the last time point, images from apical and basal focal planes are shown. (B and C) Serum-starved and siRNA-transfected A431 cells were stimulated with EGF and then stained with fluorescent phalloidin and antibodies against SH3BP1. Shown are epifluorescence images. C shows images from the dorsal aspects of the cells. Bars, 10 µm.