(A) Purified recombinant PTEN, wild-type (wt), T366A mutant or S370A mutant, was phosphorylated in vitro using CK2, GSK3β or both kinases. PTEN protein was then analysed by Western blotting using the general (Total PTEN) and phospho-specific (P-PTEN) PTEN antibodies indicated. (B) Stoichiometry of phosphorylation by CK2 and GSK3. The stoichiometry of phosphate incorporation was calculated after phosphorylation in vitro of wild-type PTEN, PTEN T366A or PTEN S370A with CK2 or GSK3.