FIG. 4.
Hemin-dependent decrease of IRP1S138E expression in HEK293 cells. The cells were either transiently transfected with pSG5-hIRP1 or stably transfected with pSG5-hIRP1S138A or pSG5-hIRP1S138E to express chimeric wild-type IRP1 (IRP1wt) (A), IRP1S138A (B), or IRP1S138E (C), respectively. All chimeric proteins are tagged with a FLAG epitope at their C termini. The cells were treated with 100 μM hemin for the indicated time intervals, and cell lysates were analyzed by Western blotting (WB) with antibodies (Ab) against IRP1 (top), FLAG (middle), or β-actin (bottom). end., endogenous; transf., transfected.