Research Article

The Peroxisomal 3-keto-acyl-CoA thiolase B Gene Expression Is under the Dual Control of PPARα and HNF4α in the Liver

Figure 5

Binding of HNF4α to TB PPRE3 is dispensable for the cooperation with PPARα/RXRα. (a) Positions of mutations used in this study. A scheme of HNF4α structure with the various domains is given: DBD, DNA-binding domain; LBD, ligand-binding domain; AF2, activation function 2 module. (b) Transactivation assays were performed in COS-7 cells with a Luc reporter vector containing isolated TB PPRE3 (b) or mouse ACOX-I PPRE (c). These constructs were cotransfected with expression vectors for both mouse PPARα (pSG5-mPPARα) and RXRα (pSG5-mRXRα) together with an expression vector encoding either wild-type HNF4α (HNF4α2 WT), a first (D126Y HNF4α2) or a second deficient form (DN HNF4) of HNF4α for DNA binding in absence (white bars) or presence (black bars) of Wy (10 μM). Values are mean of three independent experiments ±SEM. DMSO was used as vehicle. Significantly different between PPARα/RXRα and PPARα/RXRα + HNF4α with ** and *** by one-way ANOVA test.
352957.fig.005a
(a)
352957.fig.005b
(b)
352957.fig.005c
(c)