Figure 4.

Kinetic analysis of AtSUC9-mediated Suc transport in Xenopus oocytes. Currents were recorded at pH 5.0. A, Currents recorded before, during, and after application of 5 mm Suc. B, Suc-dependent currents recorded at different Suc concentrations. Background currents before and after Suc application (as in A) were averaged and subtracted from currents recorded during Suc application. C, Suc-dependent currents at a membrane potential of −137 mV (as in B) are plotted against Suc concentration. Line indicates a fit of the Michaelis-Menten equation to the data; error bars are se (n = 3 oocytes).