Fig. 3.

Gβγ enhancement of Kv7.4 channels in excised patches is prevented by PIP₂ depletion. A Representative inside-out patch recording showing stimulatory action of Gβγ. Expanded 1.75 s segments of channel openings in the absence (b) and presence of 2 ng/ml Gβγ (c) are taken from long-term recording (a). Closed state and multiple open states are denoted by C and O1–O2. B Mean concentration effect for Gβγ subunits (n = 4–7) fitted with a best-fit sigmoidal to the available data. C Representative inside-out patch recording from cell preincubated with wortmannin before (b) and after (c) Gβγ application. Subpanels b and c are expanded 2.5-s segments of channel openings taken from long-term recording (a). Closed state and multiple open states are denoted by C and O1–O2. D, Representative inside-out patch recording from cell preincubated with wortmannin before (b) and after (c) PIP₂ application. Subpanels b and c are expanded 1.35-s segments of channel openings taken from long-term recording (a). Closed state and open states are denoted by C and O1