Fig. 6.

The StarD7 promoter is synergistically activated by SF-1 and β-catenin. The 938StarD7Luc (A), 938MutSF-1Luc (B), and 938MutSF-1-TCF4Luc (C) promoter constructs were transfected alone or in combination with S33Y β-catenin, SF-1 or SF-1 235-4A, or a combination of S33Y β-catenin with SF-1 or with SF-1 235-4A expression constructs (see Materials and Methods). Cells were lysed, and luciferase activity was determined 48 h after cotransfection. Relative luciferase reporter gene activity normalized against total proteins was calculated, and results were expressed as the fold increase related to the activity in cells cotransfected with the empty expression vector defined as 1-fold. The values represent the mean ± sem of triplicate experiments. *, P < 0.05; **, P < 0.01 compared with cells cotransfected with the empty expression vector; #, P < 0.05 as indicated.