Figure 6.

GH induced reporter gene expression from the bovine HNF-3γ promoter through the identified STAT5 binding site. This was demonstrated by a cotransfection analysis. In this analysis, the plasmid pGL2B-bHNF3γP, in which the putative STAT5 binding site 2 was intact, or pGL2B-bHNF3γPm, in which the binding site was mutated, was cotransfected with a GHR expression plasmid and a STAT5b expression plasmid into CHO cells. Twenty-four hours after the transfection, the cells were serum starved for 16 h and then treated with 500 ng/ml GH or PBS (indicated as −GH) for 8 h before luciferase assay. Variation in transfection efficiency was controlled by cotransfecting the pRL-CMV plasmid. *, P < 0.05 (n =4) compared with −GH.