FIG. 3.

Effects of insulin and isoproterenol on the phosphorylation of various mutant PDE3B proteins. CHO-IR/PDE3B-WT, CHO-IR/PDE3B-S273A, and CHO-IR/PDE3B-S274A cells (A and B) and 3T3-L1 adipocytes that had been infected with AxCAPDE3B-WT, AxCAPDE3B-S273A, or AxCAPDE3B-S274A at an MOI of 20 PFU/cell (C and D) or with AxCAPDE3B-WT, AxCAPDE3B-S273A, AxCAPDE3B-S296A, or AxCAPDE3B-S421A at an MOI of 20 PFU/cell (E and F) were labeled with [³²P]orthophosphate, incubated (or not) with 100 nM insulin (A to D) or with 1 μM isoproterenol (E and F) for 15 min, and lysed. The lysates were subjected to immunoprecipitation with antibodies to HA, the immunoprecipitates were subjected to SDS-PAGE, and ³²P incorporation into PDE3B was visualized (A, C, and E) or quantitated (B, D, and F) with an image analyzer. Data are representative of three independent experiments.