Structural Studies of Ion Channel Assembly and Signaling Complexes

描述(由申请人提供)：本项目的长期目标是对离子通道的功能和调节有一个高分辨率的了解。我们重点了解电压门控离子通道(VGIC)超家族的两个样本类别KV7和TRPM通道的调制和组装所基于的体系结构基础。这些通道的大分子复合体在贯穿神经、感觉、听觉和心血管系统的生物电信号中发挥着关键作用。努力的目的是了解这些通道的细胞内模块如何与调控蛋白相互作用，以及作为这两种类型的共同特征的螺旋线圈组装域如何指导组装和组装特异性决定因素。我们集中在两个核心问题上：1)KV7 C末端尾部的钙调蛋白结合装置的结构性质是什么，疾病突变是如何影响钙调蛋白与C末端尾部的相互作用的？2)TRPM和KV7通道的细胞内组装结构域的结构性质是什么，是否有指导异构体复合体组装的共同主题？阐述潜在的KV7和TRPM结构框架对于了解这些和其他VGIC如何整合到细胞内信号通路中，以及开发新的干预方式来控制通道功能至关重要。我们的努力包括多学科的方法，包括生化、生物物理、X射线结晶学和电生理测量来解剖功能。由于其在人体生理中的重要作用，VGICs成为治疗心律失常、高血压、充血性心力衰竭、癫痫和慢性疼痛的药物靶点。因此，在原子水平上详细了解它们的结构和作用机制将极大地帮助开发出治疗各种人类疾病的有价值的治疗剂。

DESCRIPTION (provided by applicant): The long-term goals of this project are to develop a high-resolution understanding of ion channel function and regulation. We are focused on understanding the architectural foundations that underlie the modulation and assembly of two exemplar classes of the voltage-gated ion channel (VGIC) superfamily, Kv7 and TRPM channels. Macromolecular complexes of these channels play pivotal roles in bioelectrical signaling throughout the nervous, sensory, auditory, and cardiovascular systems. Efforts are directed at understanding how intracellular modules from these channels interact with regulatory proteins and how the coiled-coil assembly domains that are a common feature of both classes direct assembly and assembly specificity determinants. We focus on two central questions: 1) What is the structural nature of the calmodulin binding apparatus in the Kv7 C-terminal tail and how do disease mutations affect calmodulin interactions with the C-terminal tail? 2) What is the structural nature of the intracellular assembly domains of TRPM and Kv7 channels and are there common themes directing heteromeric complex assembly? Elaboration of the underlying Kv7 and TRPM structural framework is essential for understanding how these and other VGICs are integrated into intracellular signaling pathways and for developing novel ways to intervene to control channel function. Our efforts encompass a multidisciplinary approach that includes biochemical, biophysical, X-ray crystallographic, and electrophysiological measurements to dissect function. Because of their important role in human physiology, VGICs are the targets for drugs with great utility for the treatment of cardiac arrhythmias, hypertension, congestive heart failure, epilepsy, and chronic pain. Thus, understanding their structures and mechanisms of action at atomic level detail should greatly assist the development of valuable therapeutic agents for a wide range of human ailments.