FIGURE 8.

Activation of Akt and p44/42 MAPK signaling by recombinant gCTRP12 and fCTRP12. A, immunoblot analysis of recombinant WT CTRP12 and its gCTRP12 isoform. gCTRP12 protein consists of residue 1–21 (signal peptide) and 92–308. B, immunoblot analysis of Akt (Thr³⁰⁸) and p44/42 MAPK (Thr²⁰²/Tyr²⁰⁴) phosphorylation in 3T3-L1 adipocytes stimulated with fCTRP12 (the uncleaved 3M mutant) and gCTRP12. C, immunoblot analysis of Akt (Thr³⁰⁸) and p44/42 MAPK (Thr²⁰²/Tyr²⁰⁴) phosphorylation in H4IIE hepatocytes stimulated with fCTRP12 (uncleaved 3M mutant) and gCTRP12. Cells were stimulated with vehicle control or recombinant fCTRP12 (10 μg/ml) or gCTRP12 (10 μg/ml) for 15 min. D, 3T3-L1 adipocytes were treated with control vehicle buffer, 5 μg/ml gCTRP12, 5 μg/ml fCTRP12, with or without 100 nm insulin, and assayed for glucose uptake (n = 3). g12, gCTRP12; 3M, the uncleaved triple mutant. #, p < 0.001; *, p < 0.05 (n = 3). Error bars, S.E.