Figure 4

Coup-TFII transactivates the Ucp3 promoter in cotransfection reporter gene assays. (A) Activity of reporter gene construct -2244UCP3 luc in cotransfection experiments with various transcription factors (fold change relative to basal -2244UCP3 luc level). Coup-TFII coactivates the Ucp3 promoter in all combinations. It is especially effective together with MyoD, RXRα and p300. Coup-TFI does not activate reporter gene expression demonstrating a specific effect of Coup-TFII. (B) Identification of the region mediating Coup-TFII transctivation by analysis of deletion reporter gene constructs. Shown in the upper panel is the basal activity and induction by Coup-TFII of all constructs, in the lower panel the experiment was repeated on a background of MyoD, RXRα and p300 (note the different axis scaling). The shaded area highlights the region that is exclusively found on -2244UCP3 luc and is responsible for the Coup-TFII effect in both setups.