Figure 9

Substrate specificity of MagT1 following application of test cations, 2.0 mM, in the absence of external Mg²⁺. For clarity, only Mg²⁺,Cu²⁺, Mn²⁺, and Sr²⁺ are represented in panel A. Oocytes were clamped at a holding potential of -15 mV and stepped from -150 mV to +25 mV in 25 mV increments for 2 s for each of the cations. Values are mean ± SEM of currents measured at the end of each voltage sweep for the respective divalent cation. B, summary of permeabilities of the tested divalent cations. Figure illustrates average permeability ratios (E_rev for tested cation relative to E_rev for Mg²⁺) given in Fig. 9A.