Conformational Dynamics of hERG Potassium Channels

人类乙醚-GO相关基因(HERG，KCNH2)钾通道具有非凡的临床意义 之所以重要，是因为它们在心脏中扮演着重要的角色，在那里它们产生一种电流，使心脏重新极化 动作电位。HERG通道突变和药物抑制导致HERG和Account减少 对于一种称为长QT综合征(LQTS)的遗传性和获得性心脏病 强调这些通道在正常生理功能中的重要性。LQT的收购形式为 由于处方药的非现场作用，抑制了HERG，是一种流行和严重的临床 有问题。HERG通道具有高度专业化的门控(打开和关闭)属性，可对其进行优化 因为它们在心脏中的细胞作用以及也控制通道门控的专门亚单位组装特性。 HERG与其他调节蛋白或辅助蛋白的关联也是研究的一个主要领域 了解HERG通道是如何被监管的。提议的实验的目标是了解 这些特化背后的分子机制以及它们如何控制Herg电流。我们会的 测试我们首次展示的显示HERG的N-末端和C-末端结构域直接相互作用的最新结构 使用生化、电生理和荧光测量，以及这些结构域如何相互作用 控制通道的选通。我们的方法是尖端的，因为我们将使用电生理记录来 研究通道构象变化和荧光显微镜，以研究结构相互作用 控制通道选通和调节。我们将利用非规范氨基酸生物学的优势来介绍 HERG的小探针并在由结构引导的位置引入金属结合部位 带有过渡金属振荡器和电压的机芯。这些研究的完成将导致更大的 了解HERG通道门控的基本机制，并深入了解HERG通道门控的细胞内域是如何 通道调节开启和关闭。我们的结果有望导致理性的生物医学 心律失常的治疗策略和新的分子靶点。

Human ether á go-go related gene (hERG, KCNH2) potassium channels are of extraordinary clinical importance because they play a prominent role in heart where they generate a current that repolarizes cardiac action potentials. Mutations in hERG channels and inhibition by drugs cause a reduction in hERG and account for inherited and acquired forms of a type of heart disease known as long QT syndrome (LQTS) which emphasizes the importance of these channels in normal physiological function. The acquired form of LQT is due to the off-site effects of prescription drugs which inhibit hERG, and are a prevalent and serious clinical problem. hERG channels have highly specialized gating (opening and closing) properties that optimize them for their cellular roles in the heart and specialized subunit assembly properties that also control channel gating. The association of hERG with other regulatory or accessory proteins is also a major area of interest for understanding how hERG channels are regulated. The goal of the proposed experiments is to understand the molecular mechanisms that underlie these specializations and how they control hERG current. We will be testing recent structures showing direct N- and C-terminal domain interactions of hERG that we first showed using biochemical, electrophysiological and fluorescence measurements, and how these domain interactions control gating of the channels. Our approach is cutting-edge as we will use electrophysiological recordings to investigate channel conformational changes and fluorescence microscopy to study how structural interactions control channel gating and regulation. We will take advantage of non-canonical amino acid biology to introduce small probes to hERG and introduce metal binding sites at locations guided by structures and probe for movements with transition metal FRET and voltage. Completion of these studies will lead to a greater understanding of the basic mechanisms for hERG channel gating and insight into how intracellular domains of the channel regulate opening and closing. Our outcomes are anticipated to lead to rational biomedical strategies and new molecular target for the treatment of cardiac arrhythmias.