Fig. 4.

Copper loading increases FPN1 protein levels in J774 macrophages. J774 cells were incubated with CuSO₄ or Fe-NTA for 48 h. HeLa cells were transiently transfected with pSPORT2 CMV vector containing full-length mouse FPN1 cDNA. Total cell lysates were collected, and samples of 100 μg (J774) or 1 μg (HeLa) of protein were resolved by electrophoresis on a 10% SDS/polyacrylamide gel, then transferred to nitrocellulose. Western blot analysis was then carried out as described in Experimental Procedures. Lane 1, control (untreated) J774 cells; lane 2, J774 cells treated with 200 μM CuSO₄; lane 3, J774 cells treated with 200 μM Fe-NTA; lane 4, control (untreated) HeLa cells; and lane 5, HeLa cells transfected with full-length mouse FPN1 cDNA (HeLa-FPN1). A representative blot is shown with similar data obtained in at least three separate experiments.