FIG. 8.

Sustained activation of insulin signaling in Nfatc2^−/− Nfatc4^−/− mice. Activation of insulin receptor (IR) in adipose tissue (A), skeletal muscle (B), and liver (C) of 8-week-old Nfatc2^−/− Nfatc4^−/− (DKO) and control mice fed ad libitum with regular chow was determined at times indicated after insulin challenge (0.75 U/kg). Activation of insulin receptor downstream effectors, such as Akt protein kinase and ribosomal S6 kinase (S6K), was also determined by using phospho-Akt (P-Akt) and phospho-S6K (P-S6K) antibodies. Activation of IR was assessed by immunoprecipitation (IP) and subsequent immunoblotting (IB) analysis using phospho-Tyr antibody (P-Tyr). Time course analysis of insulin receptor activation and quantitation of insulin receptor phosphorylation were also illustrated (D).