Cell adhesion, signal transduction and cytoskeletal regulation in Drosophila

果蝇的细胞粘附、信号转导和细胞骨架调节

• 批准号: 7906599
• 负责人: Mark A. Peifer
• 金额: $ 8.16万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-31 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7906599
• 关键词: Actins; Address; Adherens Junction; Adhesions; Adult; Affect; Animal Model; Animals; Apical; Area; Autoimmune Process; Biological; Biological Models; Cadherins; Cell Adhesion; Cell Shape; Cells; Complex; Coupled; Coupling; Cues; Cytoskeleton; Data; Development; Developmental Biology; Disease; Drosophila genus; Embryo; Embryonic Development; Event; Filopodia; Foundations; Genetic; Heart Diseases; Homeostasis; Homologous Gene; Inherited; Link; Maintenance; Mechanics; Mediating; Modeling; Morphogenesis; Movement; Neoplasm Metastasis; Normal Cell; Organ; Play; Positioning Attribute; Process; Protein Tyrosine Kinase; Proteins; Receptor Protein-Tyrosine Kinases; Regulation; Role; Signal Transduction; Site; Skin; Staging; Structure; System; Testing; Textbooks; Time; Tissues; Work; Wound Healing; afadin; base; cell behavior; constriction; fly; insight; research study; scaffold; tool; tumor

DESCRIPTION (provided by applicant): The coordination of cell adhesion and cytoskeletal regulation is critical for tissue and organ assembly during embryogenesis, and also during wound repair and tissue homeostasis in adults. Disruption of cell adhesion is a critical step in tumor metastasis, and plays a role in skin and heart diseases. We have developed a model system to study coupling of cell adhesion and regulation of the actin cytoskeleton, using the fruit fly Drosophila. Tools available in this system allow us to combine very powerful genetic approaches with the ability to study cell biological events in the context of intact animals, often in real time. Work in many labs provided a static "textbook" model for how the core cadherin:catenin complex at adherens junctions (AJs) mediates adhesion and links adhesive junctions to actin. However, cells in embryos and adults are far from static. Further, certain key features of the textbook model have been called into question. Our current challenge is to revise this model, revealing how adhesion and cytoskeletal regulation are coordinated and regulated to enable the remarkably diverse cell behaviors found in developing embryos. Here we address two broad unanswered questions in this area, each providing the basis for one of our Specific Aims. Aim 1 Define mechanisms by which AJs are connected to the actin cytoskeleton and explore how these affect apical constriction, AJ remodeling and other processes. The canonical model suggests that there is a direct mechanical connection between AJs and actin, mediated by linked interactions between cadherins, ?-catenin, ??catenin, and actin. However, recent work called this into question. Defining whether and how AJs are linked to the actin cytoskeleton is a key question for our field. We hypothesize that a direct mechanical connection is critical in robust cell shape changes like those of apical constriction. Based on our preliminary data, we further hypothesize that Canoe and Rap1 help mediate this link. We will test this hypothesis, examining mechanisms by which Cno and Rap1 act, and exploring whether they play a more general role in apical constriction and AJ remodeling events. Aim 2 Define mechanisms by which adhesion and actin dynamics are coordinately regulated. To accomplish the complex cell behaviors of morphogenesis, cells must closely coordinate adhesion and actin dynamics. Defining mechanisms by which this occurs is a key task for the field. We identified critical roles for the tyrosine kinase Abl and the actin regulator Ena in morphogenesis. We use them as a model for understanding mechanisms coordinating cell adhesion and cytoskeletal regulation. We hypothesize actin regulators like Ena are stored in an inactive state at AJs. We hypothesize that Abl regulates actin assembly at AJs and nearby by regulating Ena localization and/or function, acting as a scaffold, and influencing actin directly. We hypothesize that Ena helps generate distinct actin structures using different domains and partners, and that Ena is integrated with other actin regulators in filopodia. We will test these hypotheses.

描述（由申请人提供）：细胞粘附和细胞骨架调节的协调对于胚胎发生过程中的组织和器官组装至关重要，在成人中的伤口修复和组织稳态期间也至关重要。细胞粘附的破坏是肿瘤转移的关键步骤，并且在皮肤和心脏病中起作用。我们已经开发了一种模型系统，以研究果蝇果蝇研究细胞粘附和肌动蛋白细胞骨架的调节的耦合。该系统中可用的工具使我们能够将非常强大的遗传方法与在完整动物的背景下（通常是实时的）研究细胞生物事件的能力。许多实验室的工作提供了一个静态的“教科书”模型，用于核心钙粘蛋白：粘附连接处的catenin复合物（AJS）如何介导粘附并将粘合剂连接到肌动蛋白。但是，胚胎和成人中的细胞远非静态。此外，教科书模型的某些关键特征已受到质疑。我们目前的挑战是修改该模型，揭示如何协调粘附和细胞骨架调节，并调节以使能够在发育胚胎中发现的明显多样化的细胞行为。在这里，我们解决了这个领域的两个广泛的未解决问题，每个问题为我们的特定目标之一提供了基础。 AIM 1定义了AJS连接到肌动蛋白细胞骨架的机制，并探讨了这些机制如何影响顶端收缩，AJ重塑和其他过程。 规范模型表明，AJS与肌动蛋白之间存在直接的机械连接，是由钙粘蛋白，？ - 蛋白酶，链氨酸蛋白酶和肌动蛋白之间的连接相互作用介导的。但是，最近的工作使这一问题质疑。定义AJ是否以及如何与肌动蛋白细胞骨架相关联是我们领域的关键问题。我们假设直接的机械连接在强大的细胞形状变化中至关重要，例如顶端收缩。根据我们的初步数据，我们进一步假设独木舟和RAP1有助于调解此链接。我们将检验该假设，研究CNO和RAP1的作用机制，并探索它们是否在顶端收缩和AJ重塑事件中起更一般的作用。 AIM 2定义了粘附和肌动蛋白动力学协调调节的机制。为了完成形态发生的复杂细胞行为，细胞必须紧密协调粘附和肌动蛋白动力学。定义发生这种情况的机制是该领域的关键任务。我们确定了酪氨酸激酶ABL和肌动蛋白调节剂ENA在形态发生中的关键作用。我们将它们用作理解协调细胞粘附和细胞骨架调节的机制的模型。我们假设像ENA这样的肌动蛋白调节剂存储在AJS的不活跃状态。我们假设ABL通过调节ENA定位和/或功能来调节AB的肌动蛋白组件，并直接充当脚手架，并直接影响肌动蛋白。我们假设ENA有助于使用不同的领域和伴侣生成不同的肌动蛋白结构，并且ENA与丝状肌动蛋白的其他肌动蛋白调节剂集成在一起。我们将检验这些假设。