Surface-bound Regulation of Actin Polymerization

肌动蛋白聚合的表面结合调控

• 批准号: 7029517
• 负责人: SCOT CHARLES KUO
• 金额: $ 29.84万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7029517
• 关键词: Dictyostelium; actin binding protein; actins; biomechanics; biophysics; cell motility; chemotaxis; confocal scanning microscopy; crosslink; cytoskeleton; electron microscopy; green fluorescent proteins; nonblood rheology; phagocytosis; technology /technique development; tissue /cell culture; viscosity

DESCRIPTION (provided by applicant): Changes in cell shape are important for immunological defense against pathogens and for normal tissue development, including cell migration. Aberrant regulation is a key point in some disease processes, including metastases of cancer. Because the actin cortex is responsible for these changes in cell shape, our long-term goal is to understand its regulation and its mechanisms for changing shape. We have pioneered new biophysical approaches and novel nanotechnology for probing the mechanical functions of the actin cortex. Cortical regulation often occurs with membrane-bound factors controlling a patch of cortex containing many barbed ends. By examining ARP2/3 and Ena/VASP-dependent reactions, we will probe the physicochemical constraints of membrane-surface catalysis in two modes of regulating cortical actin: lamellae and filopodia protrusions. Essentially building a model of the leading edges of cells, our longer-term Aim is to reconstitute these representative reactions for direct visualization on nanofabricated surfaces. Even without visualization, surface-adsorption already reveals biochemical interactions unexpected from solution studies. Surface-activation of ARP2/3 reveals a novel mechanical role for capping protein, whereas surface-activation of Ena/VASP suggests that certain proposed biochemical associations are not required to speed protrusion. Constituting our first two Specific Aims, understanding these two effects also requires biophysical measurements to monitor mechanical properties. In addition, understanding these two representative processes will provide a rational basis to guide development of the third, longer-term Aim of visualizing cortical dynamics.

描述（由申请人提供）：细胞形状的变化对于针对病原体和正常组织发展（包括细胞迁移）的免疫防御很重要。异常调节是某些疾病过程中的关键点，包括癌症的转移。由于肌动蛋白皮质是导致细胞形状变化的原因，因此我们的长期目标是了解其调节及其改变形状的机制。我们开创了新的生物物理方法和新型纳米技术，用于探测肌动蛋白皮质的机械功能。皮质调节通常是通过控制包含许多铁丝网末端的皮质斑块的膜结合因子进行的。通过检查ARP2/3和ENA/VASP依赖性反应，我们将在调节皮质肌动蛋白的两种模式下探测膜表面催化的物理化学约束：薄片和丝状突起。从本质上讲，建立一个细胞领先边缘的模型，我们的长期目的是重建这些代表性的反应，以直接可视化纳米制动表面。即使没有可视化，表面吸附也已经揭示了溶液研究中意外的生化相互作用。 ARP2/3的表面激活揭示了上限蛋白质的新型机械作用，而ENA/VASP的表面激活表明，某些提出的生化关联并不需要加快速度突出。构成我们的前两个特定目标，了解这两种效果还需要生物物理测量以监测机械性能。此外，理解这两个代表性过程将提供合理的基础，以指导可视化皮质动态的第三，长期目标的发展。