Microbial mobilization of the actin cytoskeleton

项目概要/摘要 肌动蛋白细胞骨架对细胞的性质和行为，包括形状，迁移和分裂至关重要。它 对于细胞-细胞和细胞-细胞外基质连接以及细胞-细胞融合也是关键的。因为这些 在细胞生理学中的许多基本功能，肌动蛋白功能障碍也是发病机制的常见贡献者， 例如炎症、心血管疾病、癌症转移和微生物感染。尽管有许多 然而，多年的研究，了解肌动蛋白组装如何在细胞质中调节和利用， 细胞内事件、细胞行为和细胞间相互作用的核心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一重要问题。 知识差距，即检查不会引起严重人类疾病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一个窗口肌动蛋白调节和功能。我们的方法 利用微生物通过其靶向肌动蛋白的能力来定殖宿主细胞的事实， 通过模仿或操纵宿主分子，使它们成为揭示 肌动蛋白调节和功能的分子机制。这一科学前提得到了许多实例的支持 微生物与宿主相互作用的研究如何增强了我们对基本细胞生物学过程的理解。 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）细胞膜上的肌动蛋白聚合是如何调节和动员的， 运动？(2)肌动蛋白是如何以及为什么被转运到细胞核内并在细胞核内聚合以进行基因表达的， 核组织、核内运动和核膜动力学？(3)肌动蛋白聚合是怎样的 质膜突起诱导细胞间融合我们将调查这些问题使用 三种模式微生物感染细胞并动员肌动蛋白，使其成为强大的细胞生物学 工具：海洋分枝杆菌作为一种工具，以了解肌动蛋白组装在膜上的调节， 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;以及Burkholderia thailandensis作为一种工具， 了解肌动蛋白在细胞融合中的作用。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，先进的成像方法， 和生物化学方法，我们处于独特的地位，以推进该领域。我们的成果将提高我们的 了解肌动蛋白调节的机制，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有关的疾病。

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.