Membrane phosphatidylinostol 4,5-bisphosphates (PtdIns(4,5)P2, PIP2) is fundamentally important for maintaining function of a large number of ion channels and transporters.We showed in our previous study that membrane depolarization induced elevation of membrane PIP2 and subsequently increased KCNQ2/Q3 currents expressed in Xenopus oocytes through increased activity of PI4 kinase.The underlying mechanism for this depolarization-induced enhancement of PIP2 synthesis was further investigated.The present results indicated that activation of protein kinase C (PKC), specifically activation of PKC isozymes βⅡ was responsible for the enhanced PIP2 synthesis.We found phorbol-12-myristate, 13-acetate (PMA), an activator of PKC, mimicked effects of the membrane depolarization by increasing KCNQ2/Q3 activity, elevating membrane PIP2 level and increasing activity of PI4 kinase.On the other hand, the membrane depolarization enhanced PKC activity.The effects of both depolarization and PMA were blocked by PKC inhibitor or PI4K RNA interference.Further results demonstrated that the depolarization selectively activated PKC βⅡ isoform and enhanced the PKC interaction with PI4 kinase.These results reveal that depolarization-induced elevation of membrane PIP2 is through activation of PKC and subsequently increased activity of PI4 kinase.