Epidermal growth factor-stimulated Akt phosphorylation requires clathrin or ErbB2 but not receptor endocytosis.

摘要: Epidermal growth factor (EGF) binding to its receptor (EGFR) activates several signaling intermediates, including Akt, leading control of cell survival and metabolism. Concomitantly, ligand-bound EGFR is incorporated into clathrin-coated pits--membrane structures containing clathrin other proteins--eventually internalization. Whether might regulate at the plasma membrane before vesicle scission poorly understood. We compared effect perturbation (preventing formation of, or recruitment to, structures) that dynamin2 (allowing but preventing internalization) under conditions in which endocytosis dependent. Clathrin by siRNA gene silencing, with inhibitor pitstop2, knocksideways silencing inhibited EGF-simulated Gab1 Akt phosphorylation ARPE-19 cells. In contrast, inhibitors did not affect EGF-stimulated phosphorylation. EGF stimulation enriched phospho-Gab1 within structures. cells have low ErbB2 expression, overexpression knockdown experiments revealed robust expression bypassed requirement for Thus scaffolds may represent unique microdomains required certain receptors, a function can be separated from formation.