Figure 4. SIRT3-deficient mice have lower phosphorylation levels of AMPK and CREB, as well as decreased PGC-1α mRNA.

(A) AMPK T-172 phosphorylation and AMPK total protein in the EDL muscles of the male wild-type mice or mice with heterozygous or homozygous SIRT3 gene deficiency were determined by Western blot analysis. AMPK phosphorylation was determined as phospho-AMPK normalized by total AMPK. N=3, *P < 0.05. (B) CREB phosphorylation and CREB total protein in the EDL muscles of the wild-type mice or mice with heterozygous or homozygous SIRT3 gene deficiency were determined by Western blotting analysis. CREB phosphorylation was determined as phospho-CREB normalized by total CREB. N=3, *P < 0.05, **P<0.01. (C) Quatitative RT-PCR shows pgc-1α mRNA level reduced in the gastrocnemius of SIRT3 knockout mice. *P < 0.05, **P<0.01.