(A) Western blots of whole cell lysates from LPS-stimulated wild type and Syk deficient cells. Blots were probed with antibodies to phospho-p85 and total GAPDH as a loading control; (B) Densitometric quantification of the ratio of phospho-p85 to total-GAPDH; (C) Wild type and Syk deficient cells were stimulated for 30 min and 1 h with 1 μg/ml LPS. Subsequently, PI3K was immunoprecipitated from cell lysates and enzymatic activity was assessed. Data are presented as the mean ±SD from three biological replicates. Syk deficiency resulted in the significant (***, p<0.001) enhancement of PIP3 generation where indicated. (D) Blots in (A) were also probed with antibodies to phospho-Akt, GSK3β, and total GAPDH as a loading control; (E) Densitometric quantification of the ratio of phospho- Akt, -GSK3β to total-GAPDH.