Short- and long-term roles of phosphatidylinositol 4, 5-bisphosphate PIP2 on Cav3.1- and Cav3.2-T-type calcium channel current. Issue 1 (March 2019)

• Record Type: Journal Article
• Authors: Liu, Yangong; Iwano, Tomohiro; Ma, Fangfang; Wang, Pu; Wang, Yan; Zheng, Mingqi; Liu, Gang; Ono, Katsushige
• Is Part Of: Pathophysiology. Volume 26:Issue 1(2019)
• Page Start: 31
• Page End: 38
• Publication Date: 2019-03
• Subjects: Phosphatidylinositol-4 -- 5-bisphosphate (PIP2) -- T-type calcium channel -- CaV3.1 -- CaV3.2; Physiology, Pathological -- Periodicals; 571.9
• DOI: 10.1016/j.pathophys.2018.12.001
• Languages: English
• ISSNs: 0928-4680

Abstract

Abstract: T-type calcium (Ca 2+ ) channels play important physiological functions in excitable cells including cardiomyocyte. Phosphatidylinositol-4, 5-bisphosphate (PIP2 ) has recently been reported to modulate various ion channels' function. However the actions of PIP2 on the T-type Ca 2+ channel remain unclear. To elucidate possible effects of PIP2 on the T-type Ca 2+ channel, we applied patch clamp method to investigate recombinant CaV 3.1- and CaV 3.2-T-type Ca 2+ channels expressed in mammalian cell lines with PIP2 in acute- and long-term potentiation. Short- and long-term potentiation of PIP2 shifted the activation and the steady-state inactivation curve toward the hyperpolarization direction of CaV 3.1-ICa.T without affecting the maximum inward current density. Short- and long-term potentiation of PIP2 also shifted the activation curve toward the hyperpolarization direction of CaV 3.2-ICa.T without affecting the maximum inward current density. Conversely, long-term but not short-term potentiation of PIP2 shifted the steady-state inactivation curve toward the hyperpolarization direction of CaV 3.2-ICa.T . Long-term but not short-term potentiation of PIP2 blunted the voltage-dependency of current decay CaV 3.1-ICa.T . PIP2 modulates CaV 3.1- and CaV 3.2-ICa.T not by their current density but by their channel gating properties possibly through its membrane-delimited actions.