FIGURE 2.

Sirt7 inhibits HIF transcriptional activity. A and B, Hep3B (A) or HeLa (B) cells were cotransfected with the indicated firefly luciferase reporter gene, which contained the ENO1 hypoxia response element upstream of a basal SV40 promoter (p2.1) or an intact promoter from the EPO, SOD2, or VEGFA gene; control Renilla luciferase reporter gene pSV-RL; HIF-1α expression vector; and either an empty vector (EV) or Sirt7 expression vector. 24 h post-transfection, cells were lysed, and the ratio of firefly to Renilla luciferase activity was determined. C and D, Hep3B (C) or HeLa (D) cells were cotransfected with the indicated luciferase promoter construct, HIF-2α expression vector, and either EV or Sirt7 expression vector. 24 h post-transfection, cells were lysed, and luciferase activity was determined. Results are shown as means ± S.E. #, p < 0.05; *, p < 0.01 versus HIF-1α or HIF-2α alone.