Table 1

Effect of inhibitors and of adenosine 5′-[β, γ-imino] triphosphate (AMP-PNP) on MgATP-dependent DNP-GS uptake by vacuolar membrane-enriched vesicles purified from pYES3-transformed and pYES3-AtMRP1-transformed DTY168 cells

TreatmentMgATP-dependent DNP-[3H]GS uptake, nmol/mg per 10 min
DTY168/pYES3DTY168/pYES3-AtMRP1
Control2.46 ± 0.08 (100.0) 4.68 ± 0.31 (100.0)
MgAMP-PNP (−MgATP)0.03 ± 0.1 (1.2)0.0 (0.0)
Bafilomycin A11.73 ± 0.14 (70.3) 4.32 ± 0.33 (92.3)
FCCP1.41 ± 0.12 (57.3) 4.20 ± 0.30 (89.7)
Gramicidin D1.77 ± 0.09 (72.0) 4.38 ± 0.20 (93.6)
Gramicidin D + bafilomycin A11.58 ± 0.23 (64.2) 4.08 ± 0.34 (87.2)
  • MgATP-dependent DNP-[3H]GS uptake was measured as described in the legend to Fig. 5 at a MgATP concentration of 3 mM unless otherwise indicated. MgAMP-PNP, bafilomycin A1, carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP), and gramicidin D were added at concentrations of 3 mM, 0.5 μM, 5 μM, and 5 μM, respectively. Values outside parentheses are means ± SE (n = 3−6); values inside parentheses are mean rates of uptake expressed as percentage of control.