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（由申请方提供）：细胞形状的变化对于针对病原体的免疫防御和正常组织发育（包括细胞迁移）非常重要。异常调节是一些疾病过程中的关键点，包括癌症的转移。由于肌动蛋白皮质负责细胞形状的这些变化，我们的长期目标是了解其调节和改变形状的机制。我们开创了新的生物物理方法和新的纳米技术，用于探测肌动蛋白皮质的机械功能。皮质调节通常发生在膜结合因子控制一片含有许多倒刺末端的皮质。通过检查ARP 2/3和Ena/VASP依赖的反应，我们将探测两种模式的调节皮质肌动蛋白的膜表面催化的物理化学约束：lameproxia和丝状伪足突起。从本质上讲，建立细胞前缘的模型，我们的长期目标是重建这些代表性的反应，以便在纳米制造的表面上直接可视化。即使没有可视化，表面吸附也已经揭示了溶液研究中意想不到的生化相互作用。ARP 2/3的表面活化揭示了加帽蛋白的一种新的机械作用，而Ena/VASP的表面活化表明，某些拟议的生化协会不需要加速突起。构成我们的前两个具体目标，了解这两个影响还需要生物物理测量，以监测机械性能。此外，了解这两个代表性的过程将提供一个合理的基础，以指导发展的第三个，更长期的目的可视化皮质动力学。