Fig. 5.
Bidentate model of CaV2.2 channel regulation by PI(4,5)P2 with different coexpressed CaV β subunits. A) Interactions between CaV2.2 and β2a subunit. The two palmitoyl fatty acyl chains of CaV β2a compete with the those of PI(4,5)P2 at the channel, reducing the need for PI(4,5)P2. See text. B). Interactions between CaV2.2, PI(4,5)P2, and β3 subunit. Non lipidated CaV β3 subunits do not compete with PI(4,5)P2 binding. The electrostatic interaction of PI(4,5)P2 with the channel is disturbed after dephosphorylation by a lipid PI(4,5)P2 5-phosphatase. See text.