FIGURE 6.
Preventing AMPKSer-485 hyperphosphorylation by mutating Ser-485 restored AICAR-induced Tau dephosphorylation by insulin pretreatment. A, HK-532 cell were infected with a lentiviral vector expressing S485A AMPK mutants or control for 5 days. S485A mutant transfection reduced both basal and AICAR-induced Ser-485 phosphorylation by AICAR. The cells were treated without or with 50 nm insulin overnight and then treated with 1 mm AICAR for 2 h. B and C, cell lysates were examined for AMPK (B) and Tau (C) phosphorylation. D, HK-532 cells were transfected with S485A or S485D AMPK mutant, and the stable clones were selected by puromycin. AICAR-induced Tau dephosphorylation was examined after without or with 50 nm overnight insulin pretreatment. E, densitometry of the result of stable AMPK mutant transfection. *, p < 0.05; #, p < 0.005.