FIG. 7.

Isoform-specific inhibitory effect of FIH-1 overexpression on transcriptional activity of HIF-1α and -2α. 293 cells (A), wild-type MEFs (B), and HIF-1α null MEFs (C) were transfected with the HRE-luciferase reporter and pRL-CMV along with either empty vector or the HIF-1α or -2α and FIH-1 expression vector. After recovery from transfection, the cells were incubated in 20% O₂ (normoxia) or 0.5% O₂ (hypoxia) for 22 h before being harvested. The y axis shows normalized firefly luciferase over Renilla luciferase activity relative to the wild-type normoxic response (bars represent the standard deviations of triplicate analyses).