RUI: The Role of Myosin Heads in Muscle Assembly

肌球蛋白头部在肌球蛋白和肌节组装过程中的作用将被研究。正在进行的研究表明，缺乏杆状序列的肌球蛋白头部的表达破坏了线虫秀丽线虫的肌节组织。有人建议进行实验，以确定肌球蛋白头部负责肌肉破坏效应的区域，并确定截断的肌球蛋白分子的门。将产生表达全长肌球蛋白或肌球蛋白头部片段的转基因线虫。将比较对照和实验转基因蠕虫的运动性和肌肉超微结构缺陷。将描述破坏肌肉组织的最小肌球蛋白片段的特征。肌肉组织的收缩机制由两种主要蛋白质--肌球蛋白和肌动蛋白组成，它们(与其他辅助蛋白质一起)排列在紧密排列的、高度有序的阵列中，称为肌节，使得肌球蛋白分子的线性阵列(收缩运动的“马达”，将化学能转化为机械能的肌动蛋白)沿肌动蛋白细丝(作为“轨迹”)移动，导致肌节缩短(从而缩短肌肉本身)。这个项目涉及肌球蛋白分子在收缩装置组装中的作用。基因操作的力量将被用来设计带有肌球蛋白分子的线虫，这些线虫在特定的位置带有突变，以确定这些特定突变的功能后果。了解收缩机械装配的结构要求是生物分子马达生物技术应用的必要前提。鉴于整个动物界肌球蛋白的高度保守性，预计线虫模型系统获得的结果将普遍适用于其他动物。

The role of myosin heads in the process of myosin and sarcomere assembly will be investigated. Work in progress indicates that expression of myosin heads lacking rod sequence disrupts sarcomere organization in the nematode, Caenorhabditis elegans. Experiments are proposed to define regions of the myosin head responsible for the muscle-disruptive effect and to determine the gate of truncated myosin molecules. Transgenic nematodes expressing full-length myosin or myosin head fragments will be produced. The motility and muscle ultrastructural defects of control and experimental transgenic worms will be compared. The smallest myosin fragment which disrupts muscle organization will be characterized. %%% The contractile mechanism of muscle tissue consists of two major proteins, myosin and actin, which are arranged (along with other auxiliary proteins) in densely packed, highly ordered arrays termed sarcomeres, such that linear arrays of myosin molecules (the "motor" for contractile movement, which transduces chemical energy into mechanical energy) move along actin filaments (which serve as the "track"), resulting in shortening of the sarcomere (and hence of the muscle itself). This project is concerned with the role of the myosin molecules in the assembly of the contractile apparatus. The power of genetic manipulations will be employed to engineer nematodes with myosin molecules bearing mutations at specific sites, to determine the functional consequence of these specific mutations. An understanding of the structural requirements for contractile machinery assembly is a necessary prerequisite to biotechnological applications of biomolecular motors. Given the high degree of conservation among myosins throughout the animal kingdom, it is expected that the results obtained with the nematode model system will be generally applicable to other animals.