Figure 3.

Voltage-dependent relief reflects transient dissociation of Gβγ from the channel at depolarized membrane potentials. Recombinant Ca_V2.2 channels expressed with β₁b and α₂δ in HEK293 cells. Gβγ was also co-expressed and produced tonic inhibition of I_Ca that could be reversed by a step to +100 mV. Lower part shows a series of superimposed currents. The interval between the conditioning prepulse to +100 mV and the following test pulse to +10 mV was increased from 10 ms to 200 ms. With longer intervals the increase in current amplitude becomes less as Gβγ rebinds to the channel. The blue line shows an exponential fit to the peak current amplitudes.