FIG. 6.

PP2A interacts with Akt in transfected fibroblasts in vivo. (A) Human primary fibroblasts were transfected with Fugene 6 reagent and 6 μg of plasmid encoding the HA-tagged PP2A catalytic subunit (HA-PP2Ac) or with empty plasmid (HA vector). After 1 h inside collagen or on fibronectin, the cells were harvested, lysed, and immunoprecipitated (i.p.) with anti-HA antibody. The immunoprecipitates were analyzed by Western blotting with antibodies against Akt or the PP2A catalytic subunit. (B) Immunoblots from whole-cell lysates (nontransfected) using the same antibodies, indicating that the antibodies against Akt and PP2A recognize the corresponding wild-type proteins and that the anti-HA antibody shows no unspecific binding to cellular proteins.