Extended Data Fig. 6: Whole-cell current responses in TRPM5-WT and E337A: Effects of CBTA and varying intracellular calcium concentrations.
From: A single allosteric site merges activation, modulation and inhibition in TRPM5
a, Representative plot showing currents measured at +100 mV and −100 mV during CBTA application (0.3 to 100 μM) and washout in TRPM5-E337A. b, Representative current-voltage relationships obtained using a ramp protocol from −100 mV to +100 mV during CBTA application (0.3 to 100 μM). In a and b, whole-cell recordings were performed with pipette solution containing 5 mM EGTA. c-h, Whole-cell current recordings in WT and E337A groups, with the pipette solution containing 1, 3, and 10 μM intracellular free calcium. Panels c, e, and g show the current-voltage relationships for TRPM5-WT(1 µM free Ca2+, n = 9; 3 µM free Ca2+, n = 11; 10 µM free Ca2+, n = 10) and E337A(1 µM free Ca2+, n = 6; 3 µM free Ca2+, n = 4; 10 µM free Ca2+, n = 4) obtained by applying step voltage protocols from −200 mV to +200 mV for 1 μM Ca2+ (c), 3 μM Ca2+ (e), and 10 μM Ca2+ (g) intracellular free calcium. Circles represent mean currents, and error bars represent s.e.m. Panels d, f, and h show representative current traces in response to step voltage protocols for 1 μM (d), 3 μM (f), and 10 μM (h) calcium groups in TRPM5-WT and E337A. 1 µM intracellular free calcium (WT: n = 9, E337A: n = 6), 3 µM (WT: n = 11, E337A: n = 4), and 10 µM (WT: n = 10, E337A: n = 4).
