Figure 2.

PAK1 WT enhances and PAK1 Y3F inhibits PRL-induced membrane ruffling. A, T47D cells stably expressing GFP alone [vector (vctr)], or GFP plus myc-tagged PAK1 WT or PAK1 Y3F were treated with or without PRL. Filamentous actin was visualized by staining with Texas Red-phalloidin (shown). Scale bar, 50 μm. C, MCF-7 cells were transfected with plasmid encoding GFP (vctr), myc-tagged PAK1 WT, or PAK1 Y3F and treated as in panel A. Scale bar, 50 μm. Arrows indicate representative ruffles in both transfected and untransfected cells, and asterisks denote transfected cells. B and D, Cells positive for GFP or antimyc were scored for the presence of ruffles for each experimental condition. The ruffling index as a number of ruffles per cell was counted. Bars represent mean ± SE. ^# P < 0.05 compared with cells expressing GFP (vctr) with the same treatment. Each experiment was repeated three times with 100 cells each time. n = 3 for each experimental condition.