Fig. 7. PLC is localized in surface protrusions and becomes redistributed to a membrane-bound fraction of blebbistatin-treated epithelial cells. (A) Caco-2 cells growing for 72 hours on Matrigel-coated coverslips were treated for 12 hours with blebbistatin (100 µM), fixed, and double-labeled for F-actin (green) and either total or active Ser1248/1249-phosphorylated PLC1 (red). Both total and active PLC1 localize within blebbistatin-induced F-actin-rich protrusions (arrows). (B) Caco-2 cells were treated with either blebbistatin or vehicle, and the amounts of membrane-bound and cytosolic PLC1 were determined by cell fractionation and western blotting. A significant increase in the amount of membrane-bound PLC1 was observed after myosin II inhibition (^*P<0.05).