Mice were injected with Ad β-gal or Ad GRP78, and livers were collected in the fed state 72 h later. Total liver extracts and total RNA were prepared and analyzed by Western blotting and qRT-PCR, respectively. (A) Total IRS-1 protein content and relative expression of IRS-1 mRNA. (B) IRS-2 total protein content and relative mRNA expression. (C and D) Tyrosine phosphorylation of IRS-1 (C) and IRS-2 (D). Shown are a representative blot and quantification of 3 independent injection series (n = 4–5 per group). (E) Serine phosphorylation of IRS-1. Shown are a representative blot and quantification of 3 independent injection series (n = 4–5 per group). (F) Total liver extracts were analyzed for phosphorylated and total JNK. (G and H) Association of the PI3K p85 subunit with IRS-1 (G) and IRS-2 (H). Shown are a representative blot and quantification of 3 independent injection series (n = 4–5 per group). *P < 0.05, **P < 0.01, ***P < 0.001 versus respective ob/+ value; #P < 0.05, ##P < 0.01, ###P < 0.001 versus respective Ad β-gal value.