STAT3 or USF2 Contributes to HIF Target Gene Specificity
Figure 1
STAT3 or USF2 alone or with HIF1α or HIF2α to activate the cloned promoters of HIF1 or HIF2 target genes in 293T cells.
A) Schematic presentation of the promoters of HIF1 target genes PGK1 and CA9. B) Schematic presentation of the promoters/enhancers of HIF2 target genes PAI1 and EPO. Predicted STAT3 {TT(N) 4-6AA} binding sites (black solid boxes), USF binding sites (CANNTG) (gray boxes), and HIF binding sites (HBS, ACGTG) (white boxes) are indicated. Previously validated HIF and USF2 binding sites are indicated by bold boxes. C) Western blot analysis of Flag-tagged STAT3C, USF2, HIF1αTM and HIF2αTM to monitor the expression of these plasmids in reporter gene assays for Figure 1D-E. Anti-beta actin was for loading control of total protein for this figure and others in the study. D) Fold of induction of CA9/Luc and PGK1/Luc reporters activated by the indicated plasmids. E) Fold of induction of PAI1/Luc and EPO/Luc reporters activated by the indicated plasmids.