Structure and Mechanics of Smooth Muscle Thin Filaments

平滑肌细丝的结构和力学

基本信息

批准号：
7329704
负责人：
WILLIAM J LEHMAN
金额：
$ 42.51万
依托单位：
BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-07-01 至 2012-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7329704
关键词：
Actin-Binding Protein Actinin Actins Adaptor Signaling Protein Affect Affinity Amino Acids Behavior Binding Binding Sites Blood Pressure Blood Vessels Blood flow Cardiovascular Agents Cell Line Cell membrane Cell physiology Cells Class Complex Condition Coupled Crosslinker Crystallography Cytoskeletal Filaments Cytoskeletal Proteins Cytoskeleton Data Disease Dystrophin Electron Microscopy Elements Extracellular Matrix F-Actin Filament Fluorescence Microscopy Goals Helix (Snails)Hot Spot Human body Hybrids In Situ Intermediate Filaments Lasers Lead Link Location Lung Maintenance Mechanics Methods Microfilaments Microscopic Molecular Molecular Conformation Molecular Structure Muscle Muscle Rigidity Numbers Organ Organelles Outcome Peptides Physiological Property Protein Binding Protein Family Proteins Range Research Personnel Resistance Resolution Role Shapes Signaling Protein Smooth Muscle Smooth Muscle Actin Staining Method Smooth Muscle Myocytes Spectrin Structure Tertiary Protein Structure Testing Thin Filament Transducers Tropomyosin Vascular System Visceral blood pressure regulation caldesmon calponin cell preparation crosslink density design ear helix experience intermolecular interaction member molecular domain molecular rearrangement monomer optical traps particle plectin programs protein B protein structure reconstruction stoichiometry transmission process

项目摘要

The actin-cytoskeleton is a major determinant of the shape of vascular smooth muscle cells and is proposed to remodel during cell contraction and distension. Cytoskeletal remodeling requires the coordinated action of actin binding proteins (ABPs) that stabilize, crosslink, cap and/or sever actin filaments. Under normal physiological conditions the vascular system experiences a wide range of mechanical forces, and it is the interactions of the cytoskeleton that enable vascular smooth muscle cells to sense and respond to mechanical distension and compression (and any disease related alterations in these forces). The goal of this proposal is to determine structural and mechanical effects of ABPs on the cytoskeleton of vascular smooth muscle cells in order to understand the properties of this essential organelle. To elucidate the effects of force on ABP binding as well as the effects of ABPs on cytoskeletal mechanics, information about the molecular structure and mechanics of the single cytoskeletal microfilaments is required. Our approach will take advantage of helical and single-particle analysis to define the location of ABP binding sites on actin, thus revealing the potential for synergy or alternatively "parking problems" between ABPs on actin filaments. In addition, we will fit atomic resolution structures into our reconstructions, thus pinpointing critical intermolecular interactions between ABPs and actin. Since ABPs may alter both filament structure and mechanics, the effects of ABP binding on actin flexural and torsional rigidity will be determined. Likewise, the mechanical effect of force applied to F-actin on the binding of ABP to filaments will be assessed. These structural and physical studies will characterize the molecular domains of ABPs that regulate cytoskeletal dynamics and mechanical behavior. This information allows us to 1) define residues that are necessary for cytoskeletal filaments to transmit and perceive forces and 2) design decoy peptides to be used by PPG members to investigate physiological function in vascular cell preparations. Lay summary: Contraction and the maintenance offeree by vascular smooth muscle cells that line blood vessels are key factors responsible for controlling blood pressure and blood flow to the organs.of the human body. We will determine the structure and mechanics of an intracellular skeleton composed of microscopic filaments, which control the shape of vascular smooth muscle cells and hence help to regulate blood pressure and blood flow.

肌动蛋白 - 细胞骨架是血管平滑肌细胞形状的主要决定因素，并提出在细胞收缩和扩张期间进行重塑。细胞骨架重塑需要协调的作用稳定，交联，盖和/或切断肌动蛋白丝的肌动蛋白结合蛋白（ABP）。在正常情况下生理条件血管系统经历了广泛的机械力，这是使血管平滑肌细胞能够感知和反应的细胞骨架的相互作用机械扩张和压缩（以及这些力的任何与疾病有关的变化）。目标该建议是确定ABP对血管细胞骨架的结构和机械作用平滑肌细胞以了解该必需细胞器的特性。阐明效果对ABP结合的力以及ABP对细胞骨架力学的影响需要单个细胞骨架微丝的分子结构和力学。我们的做法意愿利用螺旋和单粒子分析来定义ABP结合位点在肌动蛋白上的位置，从而揭示了肌动蛋白丝上ABP之间的协同作用或“停车问题”的潜力。此外，我们将将原子分辨率结构拟合到我们的重建中，从而确定关键 ABP与肌动蛋白之间的分子间相互作用。由于ABP可能会改变灯丝结构，并且力学，将确定ABP结合对肌动蛋白弯曲和扭转刚度的影响。同样，将评估应用于F-肌动蛋白对ABP与细丝结合的力的机械效应。这些结构和物理研究将表征调节细胞骨架的ABP的分子结构域动力学和机械行为。此信息允许我们到1）定义残留物所必需的残留物细胞骨架丝传递和感知力以及2）设计被PPG使用的诱饵肽成员研究血管细胞制剂中的生理功能。摘要：收缩和血管平滑肌细胞的维持量是血管的关键因素控制人体的血压和血液流向器官。我们将确定由微观细丝组成的细胞内骨骼的结构和力学，该骨骼控制着血管平滑肌细胞的形状，因此有助于调节血压和血液流动。