Figure 10.
Asp541 within the pore region is required for Mg2+ binding. (A–C) Current traces obtained with 1 mM intracellular Mg2+ for the indicated pore mutants using the protocol shown in Fig. 2 C, except that test pulses ranged from −120 to 80 mV. (D) Average normalized I-V relations of Iss for WT TRPV6 and the D541A mutant in the absence of intracellular Mg2+. (E) Comparison of the rectification scores for WT TRPV6 and four pore mutants in the presence and absence of 1 mM intracellular Mg2+. The rectification of Iss was calculated as described in Fig. 3 D. (F) Voltage dependence of the apparent Po with 1 mM intracellular Mg2+ for the four pore mutants. The solid line represents the data for WT TRPV6.