Figure 3.

Affinity of TaALMT1 for Al³⁺ as demonstrated by the relationship between the magnitude of the TaALMT1-mediated inward current and the extracellular Al³⁺ activity present in ND96LA bath medium (ND96 containing 100 μm LaCl₃). A, I/V relationship obtained for control and TaALMT1-expressing cells preloaded with malate and bathed in ND96LA solution plus Al³⁺ (activities from 0 to 19 μm Al³⁺; n = 6). B, Normalized conductances were calculated as the ratio of the corrected conductance (G_{in the presence of Al3+} − G_{in the absence of Al3+}) and the maximum conductance (at 19 μm Al³⁺) plotted against the extracellular Al³⁺ activity and fitted to the Hill equation: G = G_max/(EC₅₀ⁿ/[Al³⁺]ⁿ+1), where n is the Hill coefficient, EC₅₀ is the concentration of half enhancement, and G_max is the corrected maximum conductance. Best fitting resulted in G_max = 1.1 ± 0.1, EC₅₀ = 5 ± 1 μm Al³⁺, and a Hill coefficient of n = 1.4 ± 0.4 (r² = 0.993). Values represent averages of at least six different TaALMT1-expressing and control cells.