Figure 6.

Effect of jasplakinolide or okadaic acid on coimmunoprecipitation of myosin and PP1/PP2A. Adherent monolayers of RBL-2H3 cells that had been incubated overnight with DNP-specific IgE were incubated in a buffer containing either 5 μM jasplakinolide (A) for 3 h or 1 μM OA (B) for 45 min. Cells were subsequently left in buffer alone or activated with antigen (100 ng/ml DNP-BSA) for 2.5 min, lysed, and myosin immunoprecipitated using the anti-myosin polyclonal antibody as detailed in MATERIALS AND METHODS. Myosin immunoprecipitates were probed for PP1c, PP2Ac, and actin by Western blotting. The images are representative of those seen in two separate experiments.