Current amplitudes in WT and residue-substituted channels. (A) Current amplitude of WT and TM10 alanine-substituted RyR2s at 60 mV after activation by 20 µM EMD 41000. (B) Equivalent current amplitudes after channel modification by 1 µM ryanodine. Data are plotted as mean values (±SEM; n = 4–7; *, P < 0.05; **, P < 0.01).