Fig. 2.

Immunoblotting analysis of the expression levels of wild-type and mutant BCRP. The protein levels of wild-type and mutant BCRP in stably transfected human embryonic kidney-293 (HEK-293) cells were determined by immunoblotting and densitometric analysis. A: representative immunoblot of whole cell lysates for wild-type and mutant BCRP. The numbers below the blot refer to the average protein levels of the mutants relative to wild-type BCRP after normalization to β-actin. B: the relative protein levels of wild-type and mutant BCRP determined by immunoblotting of whole cell lysates are presented as means ± SD of 5 experiments. C: a representative immunoblot of plasma membrane preparations for wild-type and mutant BCRP. The numbers below the blot refer to the average protein levels of the mutants relative to wild-type BCRP. D: the relative protein levels of wild-type and mutant BCRP determined by immunoblotting of plasma membrane preparations are presented as means ± SD of 3 experiments.