The activation of AMPK by LKB1. A) LKB1 activation. Immunoblot analyses were performed on lysates of HepG2, H4IIE and AML12 cells that had been treated with RGE for the indicated time period. B) Phosphorylation of AMPKα by LKB1. Immunoblot analyses were performed on lysates of LKB1 null HeLa cell and LKB1 wild-type HepG2 cells following treatment of RGE for 30 mins. Results were confirmed by repeated experiments. C) Reduction of AMPKα phosphorylation by knock-down LKB1. D) The effect of CaMKK-β inhibitor on the activation of AMPK by RGE. After treatment with 1 μg/ml STO-609, HepG2 cells were continuously incubated with RGE.