Figure 5.

The TaALMT1 inward current does not cotransport Na⁺. The top panel shows examples of families of currents from TaALMT1-expressing cells preloaded with malate (left) or water (right) in response to voltage pulses ranging from −140 to +60 mV (see “Materials and Methods” for detailed protocol). Currents were first recorded in ND96LA lacking or containing 100 μm AlCl₃ (10 μm Al³⁺ activity). The bath solution was then changed to a solution in which NaCl was replaced by choline chloride (see Table I for detailed composition of the bath solution) lacking or containing AlCl₃ at an identical concentration as described above. The bottom panel shows the mean I/V relationships for TaALMT1 (circles) and control (triangles) cells preloaded with malate or water (as indicated at the top of the panel) recorded when the bath solution consisted of choline chloride in the absence (white symbols) or presence (black symbols) of 100 μm AlCl₃ in the bath solution. The inset for each set of I/V curves highlights the net inward TaALMT1-mediated current obtained after subtraction of the endogenous currents recorded in control cells bathed in solution of identical ionic composition. The arrows indicate the E_rev (n = 8).