Fig. 6.

PIP₂ and Gβγ are synergistic regulators of Kv7.4 channels. A Representative inside-out patch recording showing lack of effect of 1 ng/ml Gβγ on channel activity. Subpanel b is an expanded 1.65-s segment of channel openings taken from long-term recording (a). Closed and open states are denoted by C and O1. B Application of 3 μM PIP₂ in the presence of 1 ng/ml Gβγ (patch from (A)) significantly increased channel activity. Subpanel b is an expanded 1.65-s segment of channel openings taken from long-term recording (a). Closed state and multiple open states are denoted by C and O1–O3. C Mean apparent open probability for Kv7.4 in control conditions (n = 16), after application of low concentrations of Gβγ (n = 8) and PIP₂ alone (n = 8) and in combination (n = 6). D Mean apparent open probability for Kv7.4 activated by PIP₂ alone (n = 4–11, dark blue columns) and in the presence of 1 ng/ml Gβγ (cyan columns, n = 4–10)