Fig. 1: Overall architecture of the TRPC1/C5 with a 1:3 stoichiometry.

a, b Cryo-EM density map (a) and atomic model (b) of the TRPC1/C5 heteromer viewed from the side (left) and the top (right). c Schematic illustrations of the concatemer constructs used for electrophysiology experiments (TRPC5–TRPC5, TRPC5–TRPC1, and TRPC1–TRPC1) are presented, together with the possible tetramer combinations under the specified expression conditions, shown in separate boxes. The linker sequences are AELKLRILQSTVP for the TRPC5–TRPC5 concatemer, SAGSGGSGSLIEPG for the TRPC5–TRPC1 concatemer, and GSGGSGSLIS for the TRPC1–TRPC1 concatemer. d Representative (−)-Englerin A (EA)-induced current traces (left; inward and outward traces represent current responses from ± 100 mV, respectively, from every ramp pulse) and I–V relationships (right) obtained from the time point marked by a triangle are displayed using the same color scheme in (c). e Summary of the statistical data for inward and outward current responses induced by EA (positive data points represent current amplitudes at + 100 mV; negative data points represent current amplitudes at − 100 mV). f Diagrammatic representation of potential TRPC channel assemblies. ECFP or EYFP tags were attached to the amino termini of the channels (left). On the right, the tetrameric configurations of ECFP- or EYFP-tagged TRPC1 with TRPC5 (top), ECFP-tagged TRPC1 with EYFP-tagged TRPC5 (middle), and ECFP- or EYFP-tagged TRPC5  with TRPC5 are shown (bottom). g Quantitative summary of the FRET efficiency (E_FRET) measurements obtained through the donor-centric method across all tested subunit combinations (n = 12, ECFP + EYFP; n = 9, ECFP–TRPC1 + EYFP–TRPC1; n = 9, TRPC5 + ECFP–TRPC1 + EYFP–TRPC1; n = 12, ECFP–TRPC1 + EYFP–TRPC5; n = 15, ECFP–TRPC5 + EYFP–TRPC5; n = 22, TRPC5 + ECFP–TRPC5 + EYFP–TRPC5). n represents a number of independent cells. Comparisons between groups were conducted using a two-sided Student’s t test. Bars represent the mean ± s.e.m. **p  <  0.01, ****p  < 0.0001.