PI5KI isoform silencing impairs receptor-triggered PLCγ activity. (A) Uninfected, shRNA-ctr, shRNA-PI5KIα, or shRNA-PI5KIγ NK92 populations were left unstimulated or were stimulated with anti-2B4-coated polystyrene beads for the indicated times. Lipids were extracted and IP3 levels were measured. Data are expressed as mean plus or minus SD from 3 independent experiments. (B) The same cell populations were left unstimulated or were stimulated with anti-2B4 mAb. PLCγ1 and PLCγ2 immunoprecipitates were analyzed by immunoblotting with anti-pTyr mAb. The same membranes were reprobed with anti-PLCγ1 or PLCγ2 Ab for sample normalization. One representative experiment of 4 performed is shown.