Crosstalk between cholesterol and PIP2 in the regulation of Kv7.2/Kv7.3 channels

Abstract

Abstract It is well known that Kv7 channels activation is critically dependent on the lipid phosphatidylinositol 4,5-bisphosphate (PIP2). Furthermore, we have recently shown that Kv7.2/Kv7.3 channels are finely modulated by cholesterol. In this study, we have investigated the crosstalk between cholesterol and PIP2 in the regulation of Kv7.2/Kv7.3 channels transiently expressed in HEK-293 cells. To evaluate the effect of cholesterol on PIP2-mediated regulation of Kv7.2/Kv7.3 channels, methyl-β-cyclodextrin was acutely applied to decrease the plasma membrane cholesterol level. Currents passing through Kv7.2/Kv7.3 channels in cholesterol-depleted cells were less sensitive to PIP2 dephosphorylation strategies, either via the voltage-sensitive phosphatase Dr-VSP or the rapamycin-translocatable lipid 5-phosphatase system, compared to control cells, suggesting that cholesterol depletion limits the action of these phosphatases, probably by strengthening the interaction between Kv7.2/Kv7.3 channels and PIP2. In contrast, the sensitivity of the Kv7.2/Kv7.3 channels to acute membrane cholesterol depletion by methyl-β-cyclodextrin was not modified in channels with different apparent affinities for PIP2. Taken together, our results reveal a novel functional crosstalk between cholesterol and PIP2 in the regulation of Kv7.2/Kv7.3 channels.