Fig. 8. Electrophoretic mobility shift assays (EMSAs) for IRPs in HEK-293 cells in response to iron loading (FAC), iron chelation (DFO), treatment with hydrogen peroxide (100 µM for 30 minutes), and IL-1ß (10 ng/ml for 16 hours). The IRP/IRE interaction decreases with iron and IL-1ß treatments in both the cytosolic and membrane fractions, and IRP/IRE interaction increases with DFO and hydrogen peroxide treatments in both the cytosolic and membrane fractions. The data suggest IRPs localize to the cytosolic fraction with iron treatment and localize to the membrane fraction with H₂O₂ treatment. ^*P<0.05.