Biophysical mechanisms of mechanical tension sensing at cellular integrin complexes

细胞整合素复合物机械张力传感的生物物理机制

基本信息

批准号：
8800174
负责人：
Alexander R Dunn
金额：
$ 28.82万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-05-01 至 2019-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8800174
关键词：
Address Adhesions Award Binding Biological Biology Biophysical Process Blood flow Cancer Biology Cardiovascular Diseases Cell Adhesion Cell physiology Cells Cellular Mechanotransduction Cellular Structures Cellular biology Clinical Trials Complex Cues Cytoskeleton Data Disease Embryonic Development Energy Transfer Exercise Extracellular Matrix Focal Adhesions Goals Growth Health Health Benefit Human Image Individual Integral Membrane Protein Integrins Knowledge Laboratories Life Link Malignant Neoplasms Maps Measures Mechanics Mediating Medical Microscopy Molecular Muscle Neoplasm Metastasis Physiological Play Process Property Proteins Publishing Reporting Research Research Personnel Resolution Rest Role Signal Transduction Signal Transduction Pathway Social Welfare Stimulus Stretching Structural Models Structure Techniques Testing Therapeutic Time Tissues Transducers Tumor Angiogenesis United States National Institutes of Health Work Wound Healing base biophysical properties cancer cell cell motility experience immune function interest light microscopy macromolecular assembly migration molecular assembly/self assembly molecular scale nanometer nanoscale physical property public health relevance response sensor single molecule stem cell biology stem cell differentiation tool transmission process unpublished works

项目摘要

DESCRIPTION (provided by applicant): Our goal is to discover the molecular mechanisms by which integrins sense and transduce mechanical cues. Integrins are heterodimeric transmembrane proteins that link the cell's cytoskeleton to the extracellular matrix (ECM). Cells use integrins to migrate, exert force on their surroundings, and to sense the physical properties of the ECM. This latter property, termed mechanotransduction, is particularly important in human health and disease. Physical tension transmitted through integrins activates intracellular signaling that in turn exerts profound effects on processes as diverse as immune function, stem cell differentiation, and cancer cell metastasis. Despite this great physiological and medical importance, the physical mechanisms by which integrins sense mechanical force are not known. We aim to close this fundamental gap in our understanding of cell biology. In published work, we have developed F�rster resonance energy transfer (FRET) based molecular tension sensors (MTSs) that report on the mechanical tensions experienced by individual integrins in living cells. We have since combined MTSs and superresolution light microscopy to, for the first time, map force transmission within integrin adhesions with nanometer spatial resolution. The qualitatively new capabilities of MTS-based imaging allow us to tackle two fundamental questions in integrin biology that until now could not be directly addressed. In Aim 1, we will determine the physical mechanisms by which integrins sense mechanical tension. In particular, we will examine the overarching hypothesis that different integrin classes sense tension via fundamentally different mechanisms, and that these differences allow the cell to sense mechanical stimuli over a wide range of forces and timescales. In Aim 2, we will characterize the force transducing and sensing machinery in micron-sized integrin assemblies, termed focal adhesions (FAs), for the first time. Specifically, we will test the hypothesis that FAs contain highly coordinated, force-sensing microdomains, a prediction that cannot be tested using conventional techniques. This work will transform our understanding of cellular mechanotransduction by uncovering the molecular assemblies and biophysical mechanisms by which cells sense and transduce mechanical signals. More broadly, the mechano-responsiveness and compositional complexity that characterize FAs are also present in many other cellular structures. The conceptual and technical approaches developed in this project have the capacity to transform multiple fields of research by introducing powerful new single-molecule biophysical measurements in the context of intact, living cells.

描述（由适用提供）：我们的目标是发现整联蛋白感知和传递机械提示的分子机制。整联蛋白是将细胞的细胞骨架与细胞外基质（ECM）联系起来的异二聚体跨膜蛋白。细胞使用整联蛋白迁移，对周围环境施加力，并感知ECM的物理特性。后来称为机械转导的该财产在人类健康和疾病中尤为重要。通过整合素传播的物理张力激活细胞内信号传导，进而对像免疫功能，干细胞分化和癌细胞转移等潜水员的过程产生深远影响。尽管身体和医学上的重要性非常重要，但尚不清楚整合素的物理机制。我们的目标是弥合对细胞生物学的理解。在已发表的工作中，我们开发了基于FRSTER共振能量转移（FRET）的分子张力传感器（MTSS），该传感器（MTSS）报告了活细胞中各个整合素所经历的机械张力。从那以后，我们将MTS和超分辨率光学显微镜组合在一起，首次与纳米空间分辨率的整联蛋白粘附座中的映射力传递。基于MTS的成像的定性新功能使我们能够解决整合素生物学中的两个基本问题，这些问题到目前为止无法直接解决。在AIM 1中，我们将确定整联蛋白感知机械张力的物理机制。特别是，我们将研究以下总体假设，即不同的整合素类通过根本不同的机制感知张力，并且这些差异使细胞可以在各种力量和时间尺度上感知机械刺激。在AIM 2中，我们将首次在微米大小的整合素组件中表征力转导和灵敏度机制，称为焦点广告（FAS）。具体而言，我们将检验以下假设：FAS包含高度协调的力量微分域，该预测无法使用常规技术进行测试。这项工作将通过揭示细胞感知和传递机械信号的分子组件和生物物理机制来改变我们对细胞机制的理解。更广泛地说，在许多其他细胞结构中也存在着表征FA的机械反应性和复合复杂性。该项目中开发的概念和技术方法具有通过在完整的活细胞的背景下引入强大的新单分子生物物理测量来改变多个研究领域的能力。