Structures and gating mechanisms of TRP ion channels

TRP离子通道的结构和门控机制

基本信息

批准号：
9149283
负责人：
Yifan Cheng
金额：
$ 30.89万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-01 至 2019-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9149283
关键词：
Address Agonist Binding Binding Sites Biochemistry Biophysics Burning Pain Cations Chemicals Child Chili Pepper Collaborations Complex Coupling Cryoelectron Microscopy Crystallization Development Family Freezing Funding Goals Grant Health Heating High temperature of physical object Integral Membrane Protein Ion Channel Ions Irritants Knowledge Laboratories Ligand Binding Ligands Lipids Methods Molecular Biology Molecular Conformation Motion Nature Neurons Peptides Physiological Play Potassium Channel Process Protein Kinase Proteins Resolution Role Sampling Signal Transduction Sodium Channel Stimulus Structure TRP channel TRPV1 gene Technology Temperature Toxin Vanilloid Work X-Ray Crystallography afferent nerve base biological systems capsaicin receptor capsazepine cell type improved macromolecule member new technology particle posters protein structure receptor reconstruction somatosensory structural biology tool voltage voltage gated channel

项目摘要

DESCRIPTION (provided by applicant): TRP channels represent a group of non-selective cation channels that respond to a wide range of chemical and physical stimuli. It is a large and diverse superfamily, second only to potassium channels. TRP Vanilloid (TRPV) is a subfamily of thermosensitive TRP channels that enable somatosensory neurons to detect changes in ambient temperature. They are expressed in sensory nerves and/or other cell types, where they play important roles in sensing environmental noxious stimuli such as high temperature, acidic pH and natural or synthetic irritants. However, despite their intriguing roles in a number of physiological and pathophysiological processes, structural studies of TRP ion channels have been very challenging. A major bottleneck has been the difficulties in obtaining well-ordered three-dimensional (3D) crystals for any member of the TRP channel superfamily, which is a prerequisite for structure determination by X-ray crystallography as the most successful and well-established method for protein structure determination. Recent technological breakthroughs in single particle electron cryomicroscopy (cryoEM) have enabled near atomic resolution structure determination of macromolecules of various sizes and symmetry, no longer limited to highly symmetrical large object. It also enabled atomic structure determination of integral membrane proteins without requiring formation of 3D crystals. We determined the atomic structure of TRPV1 ion channel, which is the first atomic structure of the entire TRP channel family and the first atomic structure of an integral membrane protein determined by single particle cryoEM. We will use near atomic resolution single particle cryoEM as our main structural analysis tool, together with other methods in molecular biology, biochemistry and biophysics, to elucidate the mechanism that governs the functions of a subfamily of TRP channels, TRPV. We will address following specific questions: (1) what is the mechanism of polymodal activation of TRPV1 ion channel, a receptor for capsaicin; (2) what is the mechanism of thermosensitivity of TRPV channels; and (3) to improve the resolution of single particle cryoEM further to visualize ligands and ions binding. Substantial completion of these aims will advance our knowledge about the TRP channel function as well as advancing the technology of single particle cryoEM.

描述（由适用提供）：TRP通道代表一组非选择性阳离子通道，这些通道对广泛的化学和物理刺激做出了反应。它是一个大型和潜水员的超家族，仅次于钾通道。 TRP香草素（TRPV）是热敏性TRP通道的亚家族，使体感神经元能够检测到环境温度的变化。它们在感觉神经和/或其他细胞类型中表达，在这些细胞类型中，它们在感应环境有害刺激（例如高温，酸性pH，天然或合成刺激物）中起着重要作用。但是，他们在许多物理和病理生理过程中扮演着重要的角色，TRP离子通道的结构研究非常挑战。为了获得TRP通道超家族的任何成员的井井有排序的三维（3D）晶体的困难，这也是一个主要的瓶颈，还启用了整体膜的原子结构测定。它还启用了积分膜的原子结构测定。蛋白质不需要形成3D晶体。我们确定了TRPV1离子通道的原子结构，这是整个TRP通道家族的第一个原子结构，也是由单个粒子冷冻确定的整体膜蛋白的第一个原子结构。我们将使用近近原子分辨率单粒子冷冻作为我们的主要结构分析工具，以及分子生物学，生物化学和生物物理学中的其他方法，以阐明控制TRP通道亚家族功能（TRPV）功能的机制。我们将解决以下特定问题：（1）TRPV1离子通道（辣椒素接收器）的多峰激活的机理；（2）TRPV通道的热敏性机理是什么？（3）进一步改善单个粒子冷冻的分辨率以可视化配体和离子结合。这些目标的实质性完成将提高我们对TRP通道函数的了解，并提高单个粒子冷冻的技术。