Fig. 7. PI 3-kinase-dependent phosphorylation of PtdIns(4,5)P2 is not significantly stimulated by internalized EGF receptors. The pleckstrin homology domain of Akt fused to enhanced GFP (GFP-AH) was used to visualize production of PtdIns(3,4,5)P3. GFP-AH-transfected NR6 WT cells were either (A) untreated or (B) stimulated with EGF-TR for 20 minutes. (C) The cell in B was subsequently treated with LY294002 (100 µM, Calbiochem) for 10 minutes and revisualized. (D) GFP-AH-transfected NR6 WT cells were simultaneously treated with Tf-TR and unlabeled EGF for 20 minutes. Cells were visualized by confocal fluorescence microscopy.
