FIGURE 11.
Current-voltage relationships of E343Q-mediated uridine transport. Current-voltage (I-V) curves for representative E343Q-producing oocytes in 100 mm NaCl, pH 8.5 (solid squares), 100 mm ChCl, pH 5.5 (open circles), and 100 mm ChCl, pH 8.5 (solid circles) transport media were generated from the difference between steady-state currents recorded in the presence and absence of 100 μm uridine. Oocytes were clamped at a holding potential (Vh) of −50 mV and pulsed to test (Vt) ranging from −110 to +60 mV in 10-mV increments. Data points represent the mean ± S.E. from 6 to 8 oocytes. No uridine-induced currents were observed in control water-injected oocytes. Error bars are not shown where values were smaller than that represented by the symbols.