FIGURE 4.

Pharmacological phosphatase inhibitor screening on ceramide-induced ERM dephosphorylation. HeLa cells were pretreated with vehicle or with the protein phosphatase inhibitors cyclosporine A (Cyclo A; 10 μm, 3 h), calyculin A (Caly A; 20 nm, 3 h), okadaic acid (Okad. Ac; 100 nm, 3 h), and tautomycin (Tauto; 200 nm, 3 h) and treated with bSMase (50 milliunits/ml, 5 min). Of the various inhibitors evaluated, calyculin A and tautomycin blocked ERM dephosphorylation induced by bSMase. tEzrin, total ezrin.