Figure 1.

Regulation of TRPC3 by STIM1. HEK cells were transfected with TRPC3 alone or TRPC3 and the indicated constructs of STIM1. (a) The experimental protocol involves incubation of cells in media containing 150 mM Na⁺ to measure the monovalent current before and after cell stimulation with 100 μM carbachol. Na⁺ was then replaced with NMDG⁺ to determine the zero current level (dashed line). Whole-cell currents measured in cells transfected with TRPC3 alone or with STIM1^D76A, STIM1^CT or ΔERM–STIM1^D76A are shown. (b) The I/V relationships of HEK cells expressing TRPC3 before (grey trace) and after stimulation with carbachol (carb), cells transfected with TRPC3 and STIM1^D76A before (blue trace) and after stimulation with carbachol and cells transfected with ΔERM–STIM1^D76A and stimulated with carbachol. Note the typical TRPC3 I/V. (c) Summary of the results of TRPC3 alone (n = 8) and experiments with the indicated conditions (n = 5). The spontaneous current density measured before cell stimulation, the current activated by carbachol and the total current are shown. The error bars represent mean ± s.e.m.