Figure 4

Reduction in phosphorylation/activation of Akt by GT1b. (A) Phosphorylation of Akt was detected by immunoblotting with phospho-Akt (Ser473) and phospho-Akt (Thr308) antibody in cultures treated with 20 μg/ml GT1b at indicated time points. (B) The histogram shows quantification of phospho-Akt levels. (C-F) The activity of Akt was measured using immunoprecipitated Akt, and then it was mixed with the GSK-3α/β fusion protein (1 μg/assay). Phosphorylated GSK-3α/β was detected by immunoblotting with phospho-GSK-3α/β antibody. (D,F) The histograms show quantification of phospho-GSK-3α/β levels of C and E, respectively. The values represent the mean ± SEM of four to five separate experiments; *P < 0.01, **P < 0.001, significant from non-treated control cultures (0 h) (ANOVA and Student-Newman-Keuls analyses).