Figure 4. Hepatic PKCβ deficiency alters insulin signaling to promote FoxO1 degradation and keep GS activated postprandially.

(A and D) Immunoblot analyses of indicated phospho- and total proteins in the liver of HFHC-fed PKCβ^fl/fl and PKCβ^Hep–/– mice injected either with saline or insulin (5 U/kg body weight). Liver was harvested after 12 minutes, and liver extracts were subjected to SDS-PAGE and immunoblotted with indicated antibodies. Western blots are representative of 2 separate experiments performed with tissue from 4 mice. Percentage relative decrease shows the band intensity ratio of PKCβ^Hep–/– over PKCβ^fl/fl. (B and C) GS activity was measured in liver lysates + 10 mmol/L G6P and are presented as total GS activity (B) or the –/+G6P ratio (C). Each reaction was performed in triplicate. Each value represents the mean ± SEM. n = 4–6 mice/genotype; *P < 0.05 and **P < 0.005 for 2-way ANOVA followed by Bonferroni’s multiple-comparison test.