FIG. 2.

Identification of the Sp1(I) site for EAR2- and EAR3/COUP-TFI-mediated inhibition of the hLHR gene transcription. The wild-type (WT) or Sp1 site mutant hLHR promoter/reporter constructs [Sp1(I)X, Sp1(II)X, and Sp1(I,II)X] was cotransfected with pcDNA3.1 vector or with expression plasmids of EAR2 (A and B) or EAR3/COUP-TFI (C and D) in CV-1 cells. The luciferase activities are expressed as the percentage of the wild-type promoter activity in absence of the orphan receptors (100%, A and C), or as percentage of repression caused by EAR2 or EAR3/COUP-TFI for the individual promoter construct (B and D). The results were normalized by β-galactosidase activity and expressed as the means ± the SE of three independent experiments in triplicate wells.