Structure and Mechanics of Smooth Muscle Thin Filaments

平滑肌细丝的结构和力学

• 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
• 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

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，有人提出 在细胞收缩和扩张过程中进行重塑。细胞骨架重塑需要以下方面的协调行动 肌动蛋白结合蛋白 (ABP) 可稳定、交联、加帽和/或切断肌动蛋白丝。正常情况下 在生理条件下，血管系统承受着广泛的机械力，它是 细胞骨架的相互作用使血管平滑肌细胞能够感知和响应 机械扩张和压缩（以及这些力的任何与疾病相关的改变）。目标是 该提案旨在确定 ABP 对血管细胞骨架的结构和机械影响 平滑肌细胞，以了解这种重要细胞器的特性。阐明效果 对 ABP 结合的力以及 ABP 对细胞骨架力学的影响，有关 需要单个细胞骨架微丝的分子结构和力学。我们的方法将 利用螺旋和单粒子分析来确定肌动蛋白上 ABP 结合位点的位置， 从而揭示了肌动蛋白丝上 ABP 之间协同作用或“停放问题”的潜力。 此外，我们将把原子分辨率结构纳入我们的重建中，从而精确定位关键的 ABP 和肌动蛋白之间的分子间相互作用。由于 ABP 可能会改变细丝结构和 力学方面，ABP 结合对肌动蛋白弯曲和扭转刚度的影响将被确定。同样， 将评估施加到 F-肌动蛋白的力对 ABP 与细丝结合的机械效应。这些 结构和物理研究将表征调节细胞骨架的 ABP 分子结构域 动力学和机械行为。这些信息使我们能够 1) 定义必要的残基 细胞骨架丝传递和感知力，2) 设计 PPG 使用的诱饵肽 成员研究血管细胞制剂的生理功能。平躺总结：收缩和 血管内的血管平滑肌细胞的维持作用是关键因素 用于控制血压和流向人体器官的血液。我们将确定 由微观细丝组成的细胞内骨架的结构和力学，它控制着 血管平滑肌细胞的形状，因此有助于调节血压和血流。