Microbial mobilization of the actin cytoskeleton

项目概要/摘要 肌动蛋白细胞骨架对于细胞特性和行为（包括形状、迁移和分裂）至关重要。它 对于细胞与细胞、细胞与细胞外基质的连接以及细胞与细胞的融合也至关重要。因为这些 肌动蛋白功能障碍是细胞生理学中的许多重要功能，也是发病机制的常见因素， 例如，炎症、心血管疾病、癌症转移和微生物感染。尽管许多 然而，经过多年的研究，了解肌动蛋白组装是如何在细胞质中调节和利用的， 细胞核对细胞内事件、细胞行为和细胞间相互作用的影响仍然是一个关键的突出问题 在细胞生物学中。在我们 NIGMS 资助的研究中，我的实验室采取了一种独特的方法来解决这个重要问题 知识差距，即检查不会对人类造成严重后果的微生物之间的相互作用 疾病和宿主细胞肌动蛋白细胞骨架作为肌动蛋白调节和功能的窗口。我们的方法 利用微生物通过其靶向肌动蛋白的能力定植宿主细胞的事实，通常会引起放大 通过模仿或操纵宿主分子来进行细胞反应，使它们成为揭示真相的强大工具 肌动蛋白调节和功能的分子机制。这个科学前提有很多例子支持 研究微生物与宿主相互作用如何增强我们对基本细胞生物学过程的理解。 MIRA 应用中描述的研究利用微生物作为工具来解决三个基本问题 细胞生物学问题：（1）膜上的肌动蛋白聚合如何调节和动员以驱动 运动？ (2) 肌动蛋白如何以及为何被转运到细胞核内并在细胞核内聚合以进行基因表达， 核组织、核内运动和核膜动力学？ (3)肌动蛋白如何聚合 利用质膜突起来诱导细胞与细胞融合？我们将使用以下方法来调查这些问题 三种模型微生物感染细胞并动员肌动蛋白，使其具有强大的细胞生物学能力 工具：海分枝杆菌作为了解膜上肌动蛋白组装调节的工具，以驱动 细胞内运动；杆状病毒苜蓿银纹夜蛾多核多角体病毒作为工具 了解肌动蛋白在细胞核中的调节和功能；和 Burkholderia thailandensis 作为工具 了解肌动蛋白在细胞与细胞融合中的作用。通过利用我们在细胞生物学和微生物学方面的专业知识， 并部署微生物和宿主遗传方法、先进成像方法的协同组合， 和生化方法，我们具有独特的优势来推进该领域的发展。我们的成果将增强我们的 了解肌动蛋白调节机制，并可能为诊断、治疗和治疗提供新的见解 预防与肌动蛋白功能障碍相关的疾病。

PROJECT SUMMARY/ABSTRACT The actin cytoskeleton is crucial for cellular properties and behaviors including shape, migration, and division. It is also critical for cell-cell and cell-extracellular matrix connections as well as cell-cell fusion. Because of these numerous essential functions in cell physiology, actin dysfunction is also a common contributor to pathogenesis, for example, in inflammation, cardiovascular disease, cancer metastasis, and microbial infection. Despite many years of study, however, understanding how actin assembly is regulated and harnessed in the cytoplasm and nucleus for intracellular events, cellular behaviors, and cell-cell interactions remains a key outstanding problem in cell biology. In our NIGMS-funded research, my lab has taken a distinctive approach to address this important gap in knowledge, which is to examine the interactions between microbes that do not cause serious human illness and the host cell actin cytoskeleton as a window into actin regulation and function. Our approach leverages the fact that microbes colonize host cells through their ability to target actin, often eliciting amplified cellular responses by mimicking or manipulating host molecules, making them powerful tools for revealing molecular mechanisms of actin regulation and function. This scientific premise is supported by many examples of how studying microbe-host interactions has enhanced our understanding of basic cell biological processes. The research described in this MIRA application makes use of microbes as tools to address three fundamental cell biological questions: (1) How is actin polymerization at membranes regulated and mobilized to drive movement? (2) How and why is actin transported into and polymerized within the nucleus for gene expression, nuclear organization, intranuclear movement, and nuclear envelope dynamics? (3) How is actin polymerization in plasma membrane protrusions harnessed to induce cell-cell fusion? We will investigate these questions using three model microbes that infect cells and mobilize actin in a manner that makes them powerful cell biological tools: Mycobacterium marinum as a tool to understand the regulation of actin assembly at membranes to drive intracellular movement; the baculovirus Autographa californica multiple nucleopolyhedrovirus as a tool to understand the regulation and function of actin in the nucleus; and Burkholderia thailandensis as a tool to understand the role of actin in cell-cell fusion. By leveraging our expertise in both cell biology and microbiology, and deploying a synergistic combination of microbial and host genetic methods, advanced imaging approaches, and biochemical methods, we are uniquely positioned to advance the field. Our results will enhance our understanding of the mechanisms of actin regulation and may provide new insights into diagnosing, treating, and preventing diseases associated with actin dysfunction.