| Infection with adenovirus 5 expressing PP2Calpha WT increased phosphatidylinositol 3 kinase ( PI3K ) activities in the immunoprecipitate using antibody against the p 85 or p 110 subunit under both basal and insulin stimulated conditions , followed by activation of downstream steps in the PI3K pathway , such as phosphorylation of Akt , glycogen synthase kinase 3 , and atypical protein kinase C . ^^^ Moreover , knockdown of PP2Calpha by transfection of small interfering RNA led to a significant decrease in Akt phosphorylation . ^^^ |