PIP2 mediates functional coupling and pharmacology of neuronal KCNQ channels.
PIP2 mediates functional coupling and pharmacology of neuronal KCNQ channels.
复制标题
DOI：
10.1073/pnas.1705802114
复制
发表时间：
2017-11-07
影响因子：
11.1
通讯作者：
Kurata HT
中科院分区：
文献类型：
--
作者：
Kim RY;Pless SA;Kurata HT
尽管有许多药物可用于治疗癫痫，但近三分之一的患者对药物治疗无反应。Retigabine（RTG）是第一个批准的抗癫痫药物，其通过促进钾通道的激活起作用，特别针对受电压和膜磷脂PIP 2调节的神经元KCNQ通道。对RTG作用机制的深入了解将使这一独特药物类别的未来发展成为可能。在这项研究中，我们结合联合收割机电生理记录与荧光测量KCNQ通道构象，揭示通道功能，有助于RTG的戏剧性影响。我们的研究结果表明，PIP 2依赖性的通道的成孔和电压传感组件之间的相互作用是需要最佳的RTG行动。Retigabine（RTG）是一种一流的抗癫痫药物，通过激活电压门控KCNQ 2 -5钾通道抑制神经元兴奋性。瑞替加滨与成孔结构域结合，导致通道激活的电压依赖性超极化转变。为了阐明瑞替加滨结合位点是如何与电压感知的变化相结合的，我们使用电压钳荧光法来跟踪KCNQ 3电压感知结构域（VSD）对电压、瑞替加滨和PIP 2的响应的构象变化。稳态离子电导和电压传感器荧光密切重叠基础PIP 2条件下。瑞替加滨稳定孔的传导构象和活化的电压传感器构象，导致电流和荧光失活的急剧减速，但这些作用在通道：PIP 2相互作用破坏后减弱。这些发现揭示了PIP 2在偶联瑞替加滨结合改变VSD功能中的重要作用。我们确定了一个多元基序在近端C末端的瑞替加滨敏感的KCNQ通道，有助于VSD孔耦合通过PIP 2，从而影响独特的门控效应的瑞替加滨。
Despite the availability of many drugs to treat epilepsy, nearly one-third of patients are not responsive to pharmacotherapy. Retigabine (RTG) is the first approved antiepileptic drug that acts by promoting activation of potassium channels, specifically targeting neuronal KCNQ channels that are regulated by both voltage and the membrane phospholipid PIP2. A deeper understanding of the mechanism of action of RTG will enable future development of this unique drug class. In this study, we combine electrophysiology recordings with fluorometric measurements of KCNQ channel conformation to reveal channel features that contribute to the dramatic effects of RTG. Our findings demonstrate that a PIP2-dependent interaction between the pore-forming and voltage-sensing components of the channel is required for optimal RTG action. Retigabine (RTG) is a first-in-class antiepileptic drug that suppresses neuronal excitability through the activation of voltage-gated KCNQ2–5 potassium channels. Retigabine binds to the pore-forming domain, causing a hyperpolarizing shift in the voltage dependence of channel activation. To elucidate how the retigabine binding site is coupled to changes in voltage sensing, we used voltage-clamp fluorometry to track conformational changes of the KCNQ3 voltage-sensing domains (VSDs) in response to voltage, retigabine, and PIP2. Steady-state ionic conductance and voltage sensor fluorescence closely overlap under basal PIP2 conditions. Retigabine stabilizes the conducting conformation of the pore and the activated voltage sensor conformation, leading to dramatic deceleration of current and fluorescence deactivation, but these effects are attenuated upon disruption of channel:PIP2 interactions. These findings reveal an important role for PIP2 in coupling retigabine binding to altered VSD function. We identify a polybasic motif in the proximal C terminus of retigabine-sensitive KCNQ channels that contributes to VSD–pore coupling via PIP2, and thereby influences the unique gating effects of retigabine.
登录
查看更多内容
影响因子：
5.5
作者：
Murata, Yoshimichi;Okamura, Yasushi
通讯作者：
Okamura, Yasushi
影响因子：
9.9
作者：
Porter, R. J.;Partiot, A.;Alves, W. M.
通讯作者：
Alves, W. M.
影响因子：
30.8
作者：
Charlier, C;Singh, NA;Leppert, M
通讯作者：
Leppert, M
DOI：
10.1073/pnas.1016300108
发表时间：
2010-12-28
影响因子：
11.1
作者：
Osteen, Jeremiah D.;Gonzalez, Carlos;Kass, Robert S.
通讯作者：
Kass, Robert S.
影响因子：
16.6
作者：
Kim RY;Yau MC;Galpin JD;Seebohm G;Ahern CA;Pless SA;Kurata HT
通讯作者：
Kurata HT