Microtubule/Actin Interactions in Cell Motility

细胞运动中的微管/肌动蛋白相互作用

• 批准号: 6970461
• 负责人: Clare Michal Waterman
• 金额: $ 35.99万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6970461
• 关键词: Urodela; actins; cell migration; cell motility; chickens; crosslink; cytoskeletal proteins; fluorescence microscopy; green fluorescent proteins; guanine nucleotide binding protein; guanosinetriphosphatases; image processing; laboratory rabbit; microtubules; molecular /cellular imaging; protein protein interaction; proteomics; respiratory epithelium; small interfering RNA; tissue /cell culture

DESCRIPTION (provided by applicant): Microtubules (MTs) and filamentous actin (f-actin), are required for directed tissue cell motility. Spatial control of f-actin polymerization and actomyosin contraction is essential to generate a self perpetuating asymmetry of lamellipodial protrusion in the front and retraction in the rear to drive cell motility. MTs provide spatial and temporal orchestration of these f-actin-based events, however the molecular basis is poorly understood. MTs and f-actin exhibit two mechanistic categories of interactions in migrating cells. "Structural Interactions" in which f-actin and MTs are physically cross linked, and thus directly affect each other's organization and dynamics. "Regulatory Interactions" are those in which the activities of Rho-family small GTPase signaling cascades are spatiotemporally controlled by the assembly and disassembly of MTs, and at the same time, Rho GTPases regionally co-regulate the dynamics of MTs and f-actin. It is critical for our understanding of the mechanisms of polarized cell motility to discover the molecular linkages between the microtubules and actin cytoskeletons and the molecular mechanisms that regulate these linkages and the feedback between the dynamics of the actin and MT cytoskeletal arrays. Specific Aims:A.1. Test the hypothesis that specific classes of structural interactions between MTs and f-actin are required to mediate directed cell motility.A.2. Dissect the molecular mechanism of Rac1 GTPase-induced MT growth and test the hypothesis that Rac1-mediated promotion of microtubule growth is required for cell motility.A.3. Test the hypothesis that the adenomatous polyposis coli protein (ARC) mediates MT growth- activation of lamellipodial protrusion and Rac1 GTPase. A.4. Develop automated image analysis tools to quantitate the assembly, disassembly and movement of large populations of MTs in living cells. The experiments proposed in this grant will provide significant advances in our understanding of the basic mechanism of cell motility and provide important new technology that will aid in the advancement of other areas of biological science if they are achieved.

描述（由申请人提供）：微管（MT）和丝状肌动蛋白（f-肌动蛋白）是定向组织细胞运动所必需的。 f-肌动蛋白聚合和肌动球蛋白收缩的空间控制对于产生片状足前部突出和后部回缩的自我延续不对称性以驱动细胞运动至关重要。 MT 为这些基于 f-肌动蛋白的事件提供了空间和时间编排，但其分子基础却知之甚少。 MT 和 f-肌动蛋白在迁移细胞中表现出两种相互作用的机制。 “结构相互作用”，其中 f-肌动蛋白和 MT 物理交联，从而直接影响彼此的组织和动态。 “调节相互作用”是指Rho家族小GTP酶信号级联的活性由MT的组装和解体在时空上控制，同时Rho GTP酶在区域上共同调节MT和f-肌动蛋白的动态。发现微管和肌动蛋白细胞骨架之间的分子联系以及调节这些联系的分子机制以及肌动蛋白和MT细胞骨架阵列动力学之间的反馈对于我们理解极化细胞运动的机制至关重要。具体目标：A.1．检验以下假设：MT 和 f-肌动蛋白之间需要特定类别的结构相互作用来介导定向细胞运动。A.2．剖析Rac1 GTPase诱导MT生长的分子机制，并检验细胞运动需要Rac1介导的促进微管生长的假设。A.3．检验腺瘤性息肉病大肠杆菌蛋白 (ARC) 介导 MT 生长-板状足突起和 Rac1 GTP 酶激活的假设。 A.4.开发自动图像分析工具来定量活细胞中大量 MT 的组装、拆卸和运动。这笔资助中提出的实验将为我们对细胞运动基本机制的理解提供重大进展，并提供重要的新技术，如果这些实验得以实现，将有助于生物科学其他领域的进步。