Coordinated Cytoskeletal Dynamics and Membrane Remodeling in Cellular Shape Change

计划说明 我的实验室的首要研究目标是确定调节细胞形状的细胞和分子机制 变化。细胞形状变化是后生动物细胞的一个基本特征，是发育的关键， 生理学和病理学。神经网络的形成和可塑性是细胞形状的关键例子 在发育和生理过程中的变化，而细胞的形态和运动在病理上是错误的 条件，如黑色素瘤。我们研究了细胞形状变化过程中的两个主要主题：细胞形状变化的主动控制 细胞骨架，它被认为是细胞形状变化的关键，以及同时发生的 质膜，这可能不是很好的评价。尽管许多细胞骨架和膜 重塑成分已知，它们的生化和结构特征已描述，我们缺乏 系统地了解如何调节和协调这些不同的系统以协调细胞 形状改变。也许细胞形态发生中最重要的问题是理解细胞如何感知 并通过协调将这些细胞外信息转化为形状变化 细胞骨架动力学和质膜重塑；这是本提案的重点。Small的功能 GTP酶和激酶在调节细胞骨架动力学和膜方面已被广泛研究。 改建。我的实验室工作确定了E3泛素连接酶在调节细胞形状中的新角色 变化。我们鉴定了两种E3泛素连接酶，TRIM9和TRIM67，它们调节细胞骨架和胞外 蛋白质和细胞形状变化对网状蛋白的响应。细胞外形态发生蛋白Netrin促进神经细胞 形态发生与癌症进展。尽管有这些重要的后果，我们对细胞如何 将网状蛋白解释为形状变化。TRIM9和TRIM67为研究 泛素化在细胞骨架和膜重塑中的作用，以及这些功能是如何协调的 在此过程中，netrin引发了细胞形状的改变和运动。TRIM9和TRIM67具有相似的序列、定位、 和相互作用伙伴，然而我们的研究发现这些相关蛋白和 与其缺失相关的拮抗表型。该程序的主要目标是测试 TRIM9和TRIM67在Netrin依赖过程中协调细胞骨架动力学和胞吐作用的假说 多种细胞类型的形态发生。由于网织蛋白在神经元发育和癌症中都起着作用 在发病机制方面，我们的工作将利用发育中的神经元和迁移的黑色素瘤细胞作为模型系统。我们的 初步和已发表的数据表明，这两种细胞类型都对netrin有反应，并表达TRIM9和TRIM67。我们的 工作将阐明形状变化的基本一般性和细胞类型特定的机制，提供 细胞骨架和膜运输在发育过程中协调的机制认识 和转移。

PROGRAM DESCRIPTION The overarching research goal of my lab is to define cellular and molecular mechanisms mediating cellular shape change. Cellular shape change is a fundamental characteristic of metazoan cells, key to development, physiology, and pathology. The formation and plasticity of neural networks are key examples of cell shape change during development and physiology, whereas cell shape and motility goes awry in pathological conditions, such as melanoma. We study two main themes during cellular shape change: The active control of the cytoskeleton, which is acknowledged as critical to cellular shape change, and the concurrent remodeling of the plasma membrane, which is perhaps less well appreciated. Although many cytoskeletal and membrane remodeling components are known and their biochemical and structural characteristics described, we lack a systematic understanding of how these disparate systems are regulated and coordinated to orchestrate cellular shape change. Perhaps the most important problem in cell morphogenesis is understanding how cells perceive cues in their environment and convert this extracellular information into shape changes through coordinated cytoskeletal dynamics and plasma membrane remodeling; this is the focus of this proposal. Functions of small GTPases and kinases have been extensively studied in regulating cytoskeletal dynamics and membrane remodeling. Work from my lab identified an emerging role for E3 ubiquitin ligases in regulated cellular shape change. We identified two E3 ubiquitin ligases, TRIM9 and TRIM67, which regulate cytoskeletal and exocytic proteins and cellular shape changes in response to netrin. The extracellular morphogen netrin promotes neuronal morphogenesis and cancer progression. Despite these important consequences, we know little about how cells interpret netrin into shape changes. TRIM9 and TRIM67 provide an excellent opportunity to investigate the function of ubiquitination in cytoskeletal and membrane remodeling, and how these functions are coordinated during netrin triggered cell shape change and motility. TRIM9 and TRIM67 share similar sequences, localization, and interaction partners, however our studies identified distinct functions of these related proteins and antagonistic phenotypes associated with their deletion. The overarching goal of this program is to test the hypothesis that TRIM9 and TRIM67 coordinate cytoskeletal dynamics and exocytosis during netrin-dependent morphogenesis in multiple cell types. Since netrin plays roles in both neuronal development and cancer pathogenesis, our work will exploit developing neurons and migrating melanoma cells as model systems. Our preliminary and published data indicate both cell types respond to netrin and express TRIM9 and TRIM67. Our work will illuminate fundamental generalities and cell type specific mechanisms of shape change, providing mechanistic understanding of the coordination of the cytoskeleton and membrane trafficking during development and metastasis.