Deciphering the Mechanisms and Cellular Roles of Monomer-Driven Actin Dynamics

破译单体驱动的肌动蛋白动力学的机制和细胞作用

• 批准号: 10374507
• 负责人: Eric A Vitriol
• 金额: $ 22.65万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-12 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10374507
• 关键词: Deciphering; Mechanisms; Cellular; Roles; Monomer

Project Summary To divide, move, and communicate, cells rely on a dynamic actin cytoskeleton that can rapidly assemble and change. This is achieved by the polymerization of actin monomers into filaments, the construction of filament networks, and the disassembly of these networks back into monomers. Cells maintain a large monomer reserve to meet the demands of actin network assembly. Because of its size, the monomer pool was traditionally considered to be homogeneous. However, recent work by us and others has revealed distinct subgroups of monomers that can drive and modify actin dynamics in ways that profoundly influence cell behavior. These discoveries have shown us that the rules of monomer polymerization are much more complex than previously thought. Addressing this severe knowledge gap in one of the most fundamental aspects of cytoskeletal biology is paramount to understanding how actin functions in cells. It may also finally reveal why defects in monomer regulation are associated with neurodegeneration, inflammatory disorders, cardiac disease and cancer. Most of our current knowledge about actin monomer behavior comes from solution biochemistry. However, these types of experiments cannot reproduce the complex monomer-driven actin dynamics seen in cells. Therefore, we are devising strategies that merge biochemical principles with cellular imaging to reveal how monomeric actin regulates the cytoskeleton in living cells. This includes controlling protein levels with micromolar precision, using quantitative image analysis to extract rate constants and concentrations, and employing computational models to reveal how cellular geometry influences actin dynamics. Additionally, we are developing new tools to describe and quantify actin ultrastructure from super-resolution images. We will use these innovative approaches to address the following fundamental knowledge gaps about monomer-driven actin dynamics: 1) How monomers control the dynamics of complex actin networks, 2) How cell geometry contributes to monomer-regulated actin dynamics, and 3) Novel roles for monomers in the regulation of cellular processes.

项目摘要 为了划分，移动和交流，细胞依赖于可以快速组装和的动态肌动蛋白细胞骨架 改变。这是通过将肌动蛋白单体聚合到细丝中的聚合来实现的 网络，以及这些网络的拆卸回到单体。细胞保持大型单体储备 满足肌动蛋白网络组件的需求。由于其大小，单体池传统上是 被认为是同质的。但是，我们和其他人最近的工作揭示了 可以以深远影响细胞行为的方式驱动和修饰肌动蛋白动力学的单体。这些 发现表明，单体聚合规则比以前更为复杂 想法。在细胞骨骼生物学的最根本方面之一解决这一严重的知识差距 了解肌动蛋白如何在细胞中的功能至关重要。它也可能最终揭示了为什么单体缺陷 调节与神经退行性，炎症性疾病，心脏病和癌症有关。 我们当前关于肌动蛋白单体行为的知识都来自溶液生物化学。但是，这些 实验的类型无法再现细胞中看到的复杂单体驱动的肌动蛋白动力学。所以， 我们正在设计将生化原理与细胞成像合并的策略，以揭示单体肌动蛋白如何 调节活细胞中的细胞骨架。这包括使用微摩尔精度控制蛋白质水平 定量图像分析以提取速率常数和浓度，并采用计算模型 揭示细胞几何形状如何影响肌动蛋白动力学。此外，我们正在开发新工具来描述 并从超分辨率图像量化肌动蛋白超微结构。我们将使用这些创新的方法来 解决以下有关单体驱动肌动蛋白动力学的基本知识差距：1）单体如何 控制复杂肌动蛋白网络的动力学，2）细胞几何形状如何促进单体调节的肌动蛋白 动力学和3）单体在调节细胞过程中的新作用。