Fig. 7.

Reciprocal regulation of the RAF-ERK feedback loop by Cav-1. a Validation of the RAF-ERK feedback regulation. Cells were treated with the MEK inhibitor UO126 and its effect on the inhibitory phosphorylation level of C-RAF was determined. b, c Effect of ERK depletion on Cav-1 regulation of RAF, MEK, and ERK. Cells were co-transfected with si-ERK2 and WT-Cav-1 or si-Cav-1. d, e Effect of ERK depletion on Cav-1 regulation of EGF-induced cell growth. WT-Cav-1- or shCav-1-expressing sublines were transfected with si-ERK2 and incubated with EGF (10 ng/ml). Data represent means of triplicate assays (Bars, SD). f Schematic representation of the opposite functions of Cav-1 in the regulation of the RAF-ERK feedback phosphorylation loop in gastric cancer cells