Fig. 4.
Effect of glutathione depletion on copper uptake in HEK293 cells overexpressing hCTR1. A: glutathione concentrations (mM) averaged from 3 experiments in HEK293 cells overexpressing hCTR1 and treated with l-buthionine-sulfoximine (BSO). Cells were incubated for 48 h in media containing increasing concentrations of BSO before being assayed for GSH content. B: 64Cu uptake after 48 h incubation in media containing increasing concentrations of BSO, expressed as % uptake of control cells without BSO. C: Western blot showing biotinylated hCTR1 protein (and Na-K-ATPase α-subunit loading control from the same Western blot gel) from cells treated for 48 h with indicated concentrations of BSO in the medium. D: quantification of hCTR1 levels (%untreated cells) in cells incubated in medium containing indicated amounts of BSO for 48 h. The average of 5 experiments is shown.