ETYA mimics the inhibition profile of AA with different Ca_Vβ subunits. Inhibition was measured 1 min after the application of 30 µM ETYA from a holding potential of −60 mV. (A) Representative traces for Ca_V1.3b currents with β_1b, β_2a, β₃, or β₄ in the absence (CTL; black line) and presence of 30 µM ETYA (gray line) or 30 µM ETYA + 10 µM AA (blue line, for β₃). (B) Normalized representative traces from A. (C) Summary bar graphs of percent inhibition (n = 5–8). No statistical difference occurred with percent inhibition at 1 min by ETYA (gray bars) compared with AA (red bars; from Fig. 3 B). For Ca_V1.3b, β₃ currents, ETYA was bath applied for 1 min, and then ETYA + AA was added for another minute (blue bar; n = 4; *, P < 0.05).