Overexpression of Gβγ subunits results in decreased DAT uptake activity in HEK-293-DAT cells.

<p>(<b>A, B</b>) Specific [³H]-DA uptake and kinetic analysis for HEK293-DAT control cells (white bar, n = 6) or transfected with Gβ1γ2 (n = 3), Gα_i2 (n = 3), or Gα_i2Gβ1γ2 (n = 3). (<b>C</b>) Overexpression of Gβ4 (n = 5) or Gβ5 (n = 7) (gray bars), decreased [³H]-DA uptake in HEK293-DAT cells when compared to control (white bar, n = 19). Overexpression of the Gβγ scavengers (black bars), Gα_t (n = 6), or GRK2ct (n = 4) increased [³H]-DA uptake. (<b>D, E</b>) Overexpression of Gβ1γ2 (n = 4), Gβ4 (n = 5), or Gβ5 (n = 7) in HEK-DAT cells did not alter the plasma membrane levels of DAT as measured by biotinylation. T = total fraction, B = biotinylated fractions, **p<0.01.