Depletion of keratins activates AMPK and Raptor as the result of impaired glucose transport. (A and C) 14-3-3, chaperones Hsc70/Hsp70 (A), and P (Thr)-MAPK/Cdk substrate levels (C) were found to be similar, comparing protein lysates of keratin WT and KtyII^−/− E9.5 embryos by immunoblotting. (B and D) Detection of total and phosphorylated (P) proteins in protein lysates of keratin WT and KtyII^−/− E9.5 embryos by immunoblotting of three independent pools of embryo lysates. (E and F) E9.5 lysates were analyzed by Western blotting for changes in P-AMPK and Raptor in both genotypes. Total protein and phosphoprotein levels of AMPK and Raptor were quantified by densitometry and normalized to tubulin (n = 3; F). (G) E9.5 embryos were incubated at 37°C for 10 min in M2⁻ medium containing 5.5 mM glucose or 5.5 mM deoxyglucose or left untreated. E9.5 lysates were Western blotted for changes in the phosphoprotein levels of AMPK in KtyII^−/− and WT littermates. Total phosphoprotein levels of AMPK were quantified by densitometry and normalized to tubulin (n = 3). *, P < 0.05 (two-tailed t test). Error bars represent SEM.