Dissecting Mechanics of Contractile Ring Assembly

收缩环组件的剖析力学

• 批准号: 0424897
• 负责人: Dahong Zhang
• 金额: $ 50.5万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0424897&HistoricalAwards=false
• 关键词: Dissecting; Mechanics; Contractile; Ring; Assembly

Assembly of an actomyosin contractile ring that constricts the cell around the spindle equator is essential for cell cleavage. The molecular basis underlying the organization and constriction of the contractile ring is well documented, yet the mechanics of how actin filaments redistribute and assemble into the ring remains largely unknown. Accumulating evidence suggests that spindle microtubules may mediate equatorial distribution of actin filaments. However, it is unclear how microtubules interact with actin filaments in living cells. The long-term goal is to understand the mechanics of the contractile ring assembly by focusing on the interaction of microtubules with actin filaments and the incorporation of filaments into the ring. The hypothesis is that radiating spindle microtubules mediate transport of actin filaments and that pre-accumulated myosin II motors drive the incorporation of actin filaments into the contractile ring. The specific aims of this project are to mechanically create an optically clear environment in living cells and dissect the mechanism of microtubule-mediated transport of actin filaments and the mechanism of actin filament incorporation into the contractile ring. These aims will be accomplished by using a newly-developed approach that employs multimode micro-techniques to surgically remodel spindles and cells so as to mechanically dissect microtubule-mediated assembly of the contractile ring. This unique approach combines classic micromanipulation and microinjection with modern laser microbeam surgery using digital-enhanced polarization/fluorescence microscopy and spinning disc confocal microscopy. Thus, the approach permits direct micromanipulations of both non-labeled and fluorescently-labeled cytoskeleton in living cells and in vitro. This project will provide research training for undergraduate and graduate students.

肌动球蛋白收缩环的组装使细胞围绕纺锤体赤道收缩，这对细胞分裂至关重要。收缩环的组织和收缩的分子基础是有充分文献记载的，然而肌动蛋白丝如何重新分配和组装成环的机制仍然很大程度上未知。越来越多的证据表明纺锤体微管可能介导肌动蛋白丝的赤道分布。然而，目前尚不清楚微管如何与活细胞中的肌动蛋白丝相互作用。长期目标是通过关注微管与肌动蛋白丝的相互作用以及丝与环的结合来了解收缩环组装的机制。假设是辐射的纺锤体微管介导肌动蛋白丝的运输，而预先积累的肌凝蛋白II马达驱动肌动蛋白丝进入收缩环。该项目的具体目标是在活细胞中机械地创造一个光学透明的环境，并剖析微管介导的肌动蛋白丝运输机制和肌动蛋白丝融入收缩环的机制。这些目标将通过使用一种新开发的方法来实现，该方法采用多模微技术对纺锤体和细胞进行手术改造，以便机械地解剖微管介导的收缩环组装。这种独特的方法将经典的显微操作和显微注射与现代激光微束手术结合起来，使用数字增强偏振/荧光显微镜和旋转圆盘共聚焦显微镜。因此，该方法允许在活细胞和体外对非标记和荧光标记的细胞骨架进行直接微操作。该项目将为本科生和研究生提供研究培训。