Figure 5.
YAP/TAZ mediate the effect of cAMP in adipogenesis. (A) 3T3-L1 cells were treated with 10 μM forskolin or 100 μM IBMX for 1 h, or serum-starved 3T3-L1 cells were treated with 5 μM KT5720 for 1 h, and YAP phosphorylation and TAZ protein levels were determined. (B) 3T3-L1 cells were incubated under adipocyte differentiation conditions with IBMX or KT5720. (Tro) Troglitazone. IBMX increased, whereas KT5720 repressed, adipogenesis, as assessed by oil red staining. (C,D) 3T3-L1 cells were transfected with control or YAP and TAZ siRNAs (siYT), and the knockdown efficiency was determined by immunoblotting (shown in C). (D) These cells are also subjected to adipogenesis. (E) 3T3-L1 cells were transfected with control or YAP and TAZ siRNAs. Cells were treated with Tro and IBMX in the presence of vehicle (DMSO) or KT5720 as indicated. Adipocyte differentiation was measured by oil red staining. (F) Overexpression of YAP abolished IBMX- or forskolin-induced adipogenesis. (G) Following differentiation (as in F), cells were lysed, and the expression of adipogenesis marker genes was determined by real-time RT–PCR; the mRNA level was normalized to that of cells incubated in growth medium.