Figure 3.

GroPIns affects the LPS-induced activation of Erk1/2, JNK, p38, and the IKKα–β complex. A, GroPIns affects the phosphorylation of Erk1/2, JNK, and p38. B, GroPIns affects both the phosphorylation of the IKK complex and the degradation of IκBα. C, GroPIns does not affect the TNF-α-induced phosphorylation of the IKK complex and degradation of IκBα. A–C, blots, left side of the panel, monocytes were treated without or with either GroPIns or GroPIns4P (300 μm) for 20 min and for an additional 5, 10, 20, and 30 min in the presence of 0.1 μg/ml LPS (A and B) or 50 ng/ml TNF-α (C). Representative Western blots resolved using 10% SDS-PAGE and revealing phosphorylated (p-) Erk1/2 (Thr-202/Tyr-204), phosphorylated JNK (Thr-183/Tyr-185), phosphorylated p38 (Thr-180/Tyr-182), and total levels of Erk1/2, JNK, and p38 are shown. The phosphorylated IKKα–β complex (Ser-176/180 on IKKα and Ser-177/181 on IKKβ), the phosphorylated IκBα (Ser-32/36), and the total levels of IκBα are also shown. These blots are representative of three independent experiments performed with cells purified from three independent donors. A–C, bar graphs, right side of the panel, densitometric analysis of the bands was performed with ImageJ software. The protein abundance has been expressed relative to the housekeeping signal (vinculin or GAPDH).