(A) Representative immunoblots demonstrating the levels of phosphorylated and total AMPK protein in TA muscle of Tak1^fl/fl and Tak1^mKO mice. (B) Densitometry quantification of the ratio of phosphorylated and total AMPK protein. (C) Fold change in enzymatic activity of AMPK in TA muscle of Tak1^fl/fl and Tak1^mKO mice. (D) Representative immunoblots demonstrating the levels of phosphorylated and total Akt, mTOR, p38 MAPK, and unrelated protein GAPDH in TA muscle of Tak1^fl/fl and Tak1^mKO mice. Phosphorylated and total p38 MAPK and GAPDH were run on a separate gel. (E) Densitometry quantification of the ratio of phosphorylated vs. total protein levels of Akt, mTOR, and p38 MAPK. n = 6 in each group. (F) Representative EMSA gel demonstrating DNA-binding activity of NF-κB in quadriceps muscle of Tak1^fl/fl and Tak1^mKO mice. (G) Immunoblots presented here show levels of phosphorylated and total IκBα, total p100, and total p52 protein in TA muscle of Tak1^fl/fl and Tak1^mKO mice. (H) Densitometry quantification of the ratio of phosphorylated vs. total IκBα and total p100 and p52 bands in immunoblots. n = 4 or 5 in each group. Fully differentiated mouse primary myotubes were transduced with Ad.Control shRNA or Ad.TAK1 shRNA at MOI 1:50. After 48 hours, the cells were collected and analyzed. (I) Representative immunoblots demonstrating the levels of phosphorylated and total AMPK, mTOR, and p38 MAPK protein and levels of p100 and p52, TAK1, and unrelated protein GAPDH. (J) EMSA gel demonstrating DNA-binding activity of NF-κB in control and TAK1-knockdown myotube cultures. (K) Densitometry quantification of DNA-binding activity in Ad.TAK1 shRNA and Ad.Control shRNA myotube cultures. Error bars represent ± SEM. *P < 0.05, values significantly different from corresponding Tak1^fl/fl mice or control myotubes by unpaired 2-tailed t test.