Hypoxic regulation of Ft and IRP2 protein levels is reversible upon ReO₂. (A-B) HEK293 cells were grown under hypoxic conditions for 21 hours followed by ReO₂ for the indicated times or under normoxia with Df (200 μM for 16 hours) or FAC (150 μg/mL for 5 hours). (A) RNA supershift analysis of cytosolic cell extracts as described in Figure 1A. Con indicates normoxic control. Experiment was performed 3 times with a representative blot shown. (B) Immunoblot analysis of the cytosolic cell extracts used in panel A using antibodies against the indicated proteins. Con indicates normoxic control. Experiments were performed 2 (IRP1, IRP2, TfR, and m-Aco) or 3 (Ft) times with representative blots shown.