Figure 4.

Reduced nuclear content of Foxo1 protein at ZT6 and ZT18 in Mc3r^−/− mice subjected to RF relative to controls (A) and reduced rhythmicity of CS activity in Mc3r^−/− mice (B). A) Levels of Foxo1 protein were determined by Western blot in cytoplasmic and nuclear extracts of WT and Mc3r^−/− mice subjected to 7d of RF. Nuclear levels of Foxo1 were lower in Mc3r^−/− mice; however, there was no difference in cytosolic Foxo1 protein levels. B) Liver CS activity levels exhibit a rhythmic pattern in WT mice fed ad libitum (left panel) that is attenuated in Mc3r^−/− mice. RF is associated with increased CS activity, irrespective of genotype (P<0.01; right panel). However, CS activity remains lower in Mc3r^−/− mice.