Figure 3.

Insertion of YFP protein into the N-terminus of ABCG2 did not significantly affect its nucleotide-dependent MTX transport. The MTX uptake assays were carried out, according to the method described in Experimental Procedures, in triplicate with 3 μg of membrane vesicles shown in Figure 2B and 2C in the presence of varying concentrations of ATP or dATP and 10 mM DTT. A. ATP-dependent MTX transport by YFP/ABCG2. B. dATP-dependent MTX transport by YFP/ABCG2. C. ATP-dependent MTX transport by YFP/ABCG2 + E211Q. D. dATP-dependent MTX transport by YFP/ABCG2 + E211Q.