Figure 3.
pH dependence of native TRPM7 channels in WT- and C363S VSP–expressing cells. A, time courses of TRPM7 current reduction obtained when the pH of the internal solution was 8.2 (blue) and 6.5 (red) in cells expressing WT (filled) and C363S VSP (hollow). Currents measured at +84.84 mV were normalized to Imax for each cell. Only the decay phase of the current is plotted against time. B and C, current inhibition at 2 min (B) and 6 min (C) for pH 8.2 and 6.5 obtained from A. *, p < 0.001. The exponential decay time constant (τ) for WT VSP at 6.5 was 76.17 ± 1.49 s, R2 = 0.99. Internal [Mg2+] was ∼80 nm in all recordings. The membrane potential was held at −60 mV between ramps.