Fig. 2.
Expression and pharmacological properties of mutant DAT in the knockin mice. (A and B) Northern (A) and Western (B) blot analysis of total (Left) or cell surface (Right) proteins did not reveal any significant difference (P > 0.05, t test; n = 3–5) in DAT expression levels between WT and DAT-CI mice. DAT activity was measured in striatal synaptosomes in the presence of increasing concentrations of cocaine or unlabeled DA. (C) The mutant DAT was 89-fold more insensitive to cocaine inhibition than the WT DAT. (D) The maximum DA uptake activities (Vmax) did not differ significantly between DATs from WT and DAT-CI mice, but apparent affinity (Km) of the mutant DAT was significantly higher (t test; n = 7) than that of the WT DAT.