STRUCTURE AND MECHANISM OF A POLYMODAL TRP ION CHANNEL

多模式Trp离子通道的结构和机制瞬时受体电位(Trp)离子通道对感觉转导和细胞信号转导至关重要，Trp通道功能障碍与一系列遗传性和获得性疾病有关，包括癌症、慢性疼痛、高血压和神经疾病。由于其在生理学和病理生理学中的核心作用，色氨酸通道已被广泛研究，并成为最积极追求的药物靶点之一。然而，我们对Trp通道功能和治疗干预的了解取得了进展 由于缺乏大多数Trp通道的三维高分辨率结构信息而受到阻碍。我们的长期目标是发展结构和生化方法，在原子水平上阐明Trp通道的分子机制。通过发展新的方法来系统地评价色氨酸通道同源物的异源表达、纯化和优化，我们最近已经结晶了几乎全长的功能通道，并获得了初步的X-射线衍射到4.8？分辨率。有了这一技术突破和进一步的优化，我们现在能够结合X射线结晶学、单粒子冷冻电子显微镜(Cryo-EM)、膜片钳电生理学和定点突变来解决基本的分子机制。具体地说，我们的目标是确定与激动剂或拮抗剂结合的通道的高分辨率X射线和冷冻-EM结构，以及在与 调节通道活动的膜脂，并剖析与疾病相关的突变的潜在机制。我们的工作将提供Trp通道在多种功能状态下的X射线和低温EM结构，并揭示结构和分子机制。通过这样做，我们不仅将对Trp通道的功能有一个基本的了解，而且还将为合理设计治疗多种经络相关疾病的新疗法奠定基础。

Structure and Mechanism of a Polymodal TRP Ion Channel Transient receptor potential (TRP) ion channels are crucial for sensory transduction and cellular signaling, and TRP channel dysfunction is associated with a vast array of hereditary and acquired diseases including cancer, chronic pain, hypertension, and neurological disorders. Because of their central roles in physiology and pathophysiology, TRP channels have been intensively studied and are among the most aggressively pursued drug targets. However, advances in our understanding of TRP channel function and therapeutic interventions have been hindered by a lack of three-dimensional high-resolution structural information for most TRP channels. Our long-term goal is to develop structural and biochemical approaches to elucidate molecular mechanisms of TRP channels at the atomic level. By developing new methods to systematically evaluate heterologous expression, purification, and optimization of TRP channel homologs, we have recently crystallized a nearly full-length functional channel and obtained preliminary X-ray diffraction to 4.8 Å resolution. With this technical breakthrough and further optimization, we are now able to combine X-ray crystallography, single-particle cryo-electron microscopy (cryo-EM), patch-clamp electrophysiology, and site-directed mutagenesis to address fundamental molecular mechanisms. Specifically, we aim to determine high-resolution X-ray and cryo-EM structures of the channel bound with agonists or antagonists, and in complex with membrane lipids that regulate channel activity, and to dissect the underlying mechanisms of disease-associated mutations. Our proposed work will provide X-ray and cryo-EM structures of a TRP channel in multiple functional states and uncover structural and molecular mechanisms. In doing so, we will not only bring fundamental insights into TRP channel function, but also establish a foundation for rational design of new therapeutics for the treatment of many channel-associated diseases.