Dynamic PIP2 interactions with voltage sensor elements contribute to KCNQ2 channel gating.

ABSTRACT: The S4 segment and the S4-S5 linker of voltage-gated potassium (Kv) channels are crucial for voltage sensing. Previous studies on the Shaker and Kv1.2 channels have shown that phosphatidylinositol-4,5-bisphosphate (PIP2) exerts opposing effects on Kv channels, up-regulating the current amplitude, while decreasing the voltage sensitivity. Interactions between PIP2 and the S4 segment or the S4-S5 linker in the closed state have been highlighted to explain the effects of PIP2 on voltage sensitivity. Here, we show that PIP2 preferentially interacts with the S4-S5 linker in the open-state KCNQ2 (Kv7.2) channel, whereas it contacts the S2-S3 loop in the closed state. These interactions are different from the PIP2-Shaker and PIP2-Kv1.2 interactions. Consistently, PIP2 exerts different effects on

SUBMITTER: Zhang Q 

PROVIDER: S-EPMC3864334 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature