Structural Basis of “Force from Lipids” Activation in Mechanosensitive Channels

机械敏感通道中“脂质力”激活的结构基础

• 批准号: 10216309
• 负责人: Eduardo A Perozo
• 金额: $ 35.64万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10216309
• 关键词: Address; Antibiotics; Archaea; Architecture; Automobile Driving; Bacteria; Behavior; Biological; Biomedical Engineering; Cells; Communication; Computing Methodologies; Coupling; Cryoelectron Microscopy; Crystallization; Data; Data Set; Detergents; Development; Disease; Drug Delivery Systems; Elements; Environment; Event; Family; Goals; Growth; Health; Hearing; Heterogeneity; Hydrophobicity; Ion Channel; Ion Channel Gating; Libraries; Light; Lipid Bilayers; Lipids; Location; Mechanics; Membrane; Membrane Proteins; Methods; Modeling; Molecular; Molecular Conformation; Motion; Mutagenesis; Mutation; N-terminal; Nature; Nociception; Organism; Orthologous Gene; Osmoregulation; Pathway interactions; Pattern; Physiological; Physiological Processes; Plants; Play; Population; Positioning Attribute; Prokaryotic Cells; Proprioception; Proteins; Resolution; Roentgen Rays; Role; Sensory; Signal Transduction; Spin Labels; Stimulus; Structure; System; Thermodynamics; Thick; Touch sensation; base; deep sequencing; design; experience; extracellular; fascinate; feasibility research; gain of function; interfacial; mechanotransduction; member; monolayer; mutant; nanodisk; next generation sequencing; novel; particle; patch clamp; physical property; physical state; protein function; reconstitution; response; vapor

Project Summary/Abstract Mechanosensitive (MS) channels are oligomeric membrane proteins that function as mechano-electrical sensory switches in a wide range physiological processes. These include touch, hearing, proprioception, turgor control in plant cells and osmoregulation in bacteria. Among these, a fundamental class of MS channels responds to changes in the physical properties of the lipid bilayer by undergoing major structural transitions in response to membrane tension, thus fulfilling a major role in the response of living organisms to mechanical stimuli. This has been referred to as the “force from lipid” principle of mechanosensitivity. The overall, long-term goal of this project is to understand the molecular mechanism of “force from lipid” gating in mechanosensitive channels. Specifically, we will focus on the MscS family of MS channels found in most prokaryotes and plants. These channels are of fundamental importance in various physiological events, can been engineered for biomedical applications, and display fascinating intramembrane heterogeneity among family orthologs. More importantly, the MscS family Affords us the possibility of studying the functional behavior, high resolution structure and dynamics in the same MS system. Although MscL and MscS channels have been studied extensively and crystal structures have been available in multiple conformations, there are still major mechanistic questions that remain to be solved. This is particularly true for the molecular events underlying channel gating, in light of exciting new preliminary data at the core of this proposal. In this respect, we plan to experimentally address several fundamental questions: What is the physical basis of the energy transduction steps, starting with trans-bilayer tension and culminating in protein motion? What are the structures of the key functional states in its native, bilayer-embedded form? Where in the molecule does mechanical transduction occur? And how? Functional studies will be designed to understand the physical basis of energy transduction. Information on the architecture, dynamics and energetic relationship of MscS (plus other related members of the superfamily) with its surrounding lipid bilayer will be obtained from cryo-EM, EPR analysis of spin labeled mutants and computational methods. The data will be interpreted to generate high resolution structures of the different stages of the gating pathway in each type of channel. We suggest that the advent of new cryo-EM approaches to the analysis of structure and dynamics in membrane proteins in their native environment shall open an exciting new experimental avenue that will contribute to the understanding of biologically important events such as ion channel gating, nociception and signal transduction.

项目摘要/摘要 机械敏感（MS）通道是寡聚膜蛋白，可作为机械电气发挥作用 感觉开关在广泛的物理过程中。这些包括触摸，听力，本体感受，turgor 控制植物细胞和细菌中的渗透调节。其中，MS频道的基本类别 通过在重大结构过渡中进行脂质双层物理特性变化的响应 对膜张力的反应，从而在生物对机械的反应中扮演重要作用 刺激。这被称为机理敏感性原理的“力”原理。 该项目的总体长期目标是了解“脂质力”的分子机制 机械敏感通道中的门控。具体而言，我们将重点关注MSS的MSC家族。 大多数原核生物和植物。这些渠道在各种物理事件中至关重要， 可以针对生物医学应用进行设计，并显示出迷人的膜内异质性 家庭直系同源物。更重要的是，MSC家族为我们提供了研究功能的可能性 同一MS系统中的行为，高分辨率结构和动态。 尽管MSCL和MSCS通道已经进行了广泛研究，并且晶体结构已经 在多个考虑因素中可用，仍然有一些主要的机械问题要解决。这是 鉴于令人兴奋的新初步数据 该提议的核心。在这方面，我们计划在实验中解决几个基本问​​题： 从跨双层张力和最终形式开始的能量转移步骤的物理基础是什么 在蛋白质运动中？主要功能状态在其本机，双层包裹的形式中的结构是什么？ 机械转移在分子中的何处发生？以及如何？ 功能研究将旨在理解能量转移的物理基础。信息 关于MSC的体系结构，动态和充满活力的关系（加上其他相关成员 超家族）及其周围的脂质双层将从Cryo-EM获得旋转标记的EPR分析 突变体和计算方法。数据将被解释为生成高分辨率结构 每种类型的通道中门控途径的不同阶段。我们建议新的低温EM冒险 在其本地环境中膜蛋白中结构和动态分析的方法 打开一个令人兴奋的新实验途径，这将有助于理解生物学上重要的 离子通道门控，伤害感受和信号转导等事件。