Channels with KCNE Subunits: Conformational Dynamics

描述（由申请人提供）：这项工作的目标是确定KCNE亚基如何控制电压门控钾（Kv）通道。也被称为mink相关肽（MiRPs），这些单通道跨膜辅助亚基值得研究，因为它们是心脏和其他依赖Kv通道的器官正常功能所必需的。MiRPs通过与Kv通道孔隙形成亚基的组装发挥其强大的作用，从而直接定位和水平，电压敏感性，时间依赖性，单位电导，离子选择性以及对调节剂和药物的响应。鉴定和研究MiRPs对心脏疾病的诊断和治疗具有重要意义。这个应用程序的意义是双重的。首先，在过去的十年里，我们对MiRPs在心脏中的作用有了很多了解，但还不知道它们是如何做到的。其次，现在有工具可以描述构象动力学，即蛋白质实时操作的机制基础。在这里，强大的光学、电生理学和建模技术被用于研究细胞中形成的通道，这在十年前是不可想象的。结果不亚于这个：我们现在可以回答人类生理学和疾病中基本的、悬而未决的问题。这三个目标关注的是同一个成孔Kv亚基（Kv7.1 = KCNQ1 = Q1）和两个不同的MiRPs （MinK = E1和MiRP2 = E3）形成的两个重要通道的运作。这项研究解决了生理学的核心问题。也就是说：为什么心脏和耳朵的ik （Q1 + E1）对电压的反应很慢？心脏和结肠中发现的IK （Q1 + E3）对电压的瞬间反应如何？这些正常功能被遗传差异和获得性疾病所破坏。更重要的是，该研究可以揭示电压传感器和栅极工作的关键原理以及附属子单元的影响；这些见解与整个身体都有关联。

DESCRIPTION (provided by applicant): The goal of this work is to determine how voltage-gated potassium (Kv) channels are controlled by KCNE subunits. Also called MinK-related peptides (MiRPs), these single-pass transmembrane accessory subunits merit investigation because they are required for normal function of the heart and other organs that depend on Kv channels. MiRPs exert their powerful effects by assembly with Kv channel pore-forming subunits and thereby direct location and level, voltage-sensitivity, time- dependence, unitary conductance, ion selectivity, and response to regulators and pharmaceuticals. Identifying and studying MiRPs has advanced diagnosis and treatment of cardiac disease. The significance of this application is two-fold. First, we have learned a great deal about what MiRPs do in the heart over the last decade but not yet how they do it. Second, tools are now available to delineate conformational dynamics, that is, the mechanistic basis for protein operation in real-time. Here, powerful optical, electrophysiological and modeling techniques are brought to bear on channels as they form in cells, a capability unimaginable just a decade ago. The result is no less than this: we can now answer basic, outstanding questions in human physiology and disease. The three aims focus on operation of two important channels formed by the same pore-forming Kv subunit (Kv7.1 = KCNQ1 = Q1) and two different MiRPs (MinK = E1 and MiRP2 = E3). The study addresses questions at the core of physiology. To wit: why does IKs (Q1 + E1) in the heart and ear respond slowly to voltage? How does IK (Q1 + E3) found in heart and colon react instantaneously to voltage? These normal functions are disrupted by inherited differences and acquired disease. More basically, the study can reveal key principles of operation of voltage sensors and gates and the impact of accessory subunits; these insights have relevance throughout the body.