Fig. 2.

Stimulation of TRPC5 by Pb²⁺ depends on E543. Recordings were by whole-cell voltage-clamp from HEK 293 cells. (A) For a cell expressing wild type TRPC5 (WT) an example time course of current sampled at +80 mV and −80 mV during a voltage ramp and showing bath-application of 100 μM Gd³⁺. (B and C) For a cell expressing E543Q TRPC5, an example time course of current showing bath-application of 100 μM Gd³⁺ (B) or 10 μM Pb²⁺ (C) and 5 μM S1P in sequence. Methanol concentration was kept constant before and after S1P application. S1P, sphingosine-1-phosphate. (D) Mean change in current amplitudes at −80 mV and +80 mV evoked by 10 μM Pb²⁺ or 5 μM S1P in cells with wild type TRPC5 (n = 3; open bars) and E543Q mutant form of TRPC5 (n = 4) over-expression. (E) Current–voltage relationship (I–V) for the experiment in (C) showing the basal current, the current in the presence of Pb²⁺, and after S1P application.