Microbial mobilization of the actin cytoskeleton

项目摘要/摘要 肌动蛋白细胞骨架对细胞的性质和行为，包括形状、迁移和分裂都是至关重要的。它 对细胞-细胞、细胞-细胞外基质连接以及细胞-细胞融合也是至关重要的。正因为如此 细胞生理学中的许多基本功能，肌动蛋白功能障碍也是导致发病的共同因素， 例如，在炎症、心血管疾病、癌症转移和微生物感染方面。尽管有很多人 然而，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，以及 细胞内事件、细胞行为和细胞间相互作用的核仍然是一个关键的悬而未决的问题 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的问题 知识鸿沟，即研究微生物之间的相互作用，这些微生物不会对人类造成严重影响 疾病和宿主细胞肌动蛋白细胞骨架作为了解肌动蛋白调控和功能的窗口。我们的方法 利用这样一个事实，即微生物通过其靶向肌动蛋白的能力来定植宿主细胞，通常引起扩增 通过模仿或操纵宿主分子的细胞反应，使它们成为揭示 肌动蛋白调控和功能的分子机制。这一科学前提得到了许多例子的支持 研究微生物与宿主的相互作用如何增强了我们对基本细胞生物学过程的理解。 这项Mira申请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)肌动蛋白在膜上的聚合如何被调节和动员以驱动 运动？(2)肌动蛋白如何以及为什么运输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)肌动蛋白聚合是如何进行的 质膜突起被用来诱导细胞-细胞融合？我们将使用以下工具调查这些问题 三种感染细胞并动员肌动蛋白的模型微生物，使它们具有强大的细胞生物学能力 工具：海洋分枝杆菌作为工具来了解肌动蛋白在膜上组装的调节驱动 细胞内运动；加州链球杆状病毒多核型多角体病毒 了解肌动蛋白在细胞核中的调节和功能；以及泰兰伯克霍尔德氏菌作为工具 了解肌动蛋白在细胞-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， 以及部署微生物和宿主遗传方法、先进成像方法、 与生物化学方法相比，我们在这一领域具有独特的优势。我们的结果将增强我们的 了解肌动蛋白的调节机制，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.