PROPERTIES OF AXONAL TUBULIN RELATED TO NEURONAL GROWTH

该提议集中于两个主要目标：1）轴突的表征 微管蛋白和微管; 2）评价微管蛋白所起的作用 以及轴突的生长和再生。 微管蛋白是一种主要的蛋白质 大脑和知识的性质，神经元微管蛋白和 微管对于理解微管蛋白在 神经元功能 轴突运输研究表明， 轴突微管蛋白是冷不溶性的，并且在生物化学上不同于 微管中的微管蛋白通过从全脑循环制备。 的 冷不溶性微管蛋白的形态学相关性被证明是稳定的 微管的片段。 这种稳定的微管片段会影响 轴突细胞骨架的动力学，可以作为局部的功能， 轴突中微管聚合的调节剂。 研究计划 将涉及开发冷不溶物的纯化程序 神经组织中的微管蛋白。 两种轴突微管蛋白均被轴突标记 将分析运输和纯化的冷不溶性微管蛋白以确定 轴突微管冷稳定性的生化基础。 特别 重点将放在可能的翻译后修改上， 微管相关蛋白的差异。 的属性和 冷稳定微管的生物学功能将通过 检测不溶性微管蛋白对微管组装的影响， 体外 冷不溶物的量、形态和变化 微管蛋白在不同的神经元和再生的神经突起将被评估 生物化学和免疫化学。 这些研究将提供更好的 了解微管蛋白和微管在细胞凋亡中的作用， 神经元的功能，以及确定分子机制， 调节神经元微管蛋白的性质。

This proposal focuses on two major goals: 1) characterization of axonal tubulin and microtubules; and 2) evaluation of the roles played by tubulin and axonal growth and regeneration. Tubulin is one of the major proteins of brain and knowledge about the properties of neuronal tubulin and microtubules is essential for understanding the roles played by tubulin in neuronal function. Axonal transport studies have shown that the bulk of axonal tubulin is cold insoluble and biochemically distinct from the tubulin in microtubules prepared by cycling from whole brain. The morphological correlate of cold insoluble tubulin was shown to be stable segments of microtubules. Such stable microtubule segments would affect the dynamics of the axonal cytoskeleton and could function as local regulators of microtubule polymerization in the axon. The plan of research will involve development of procedures for purification of cold insoluble tubulin from nervous tissue. Both axonal tubulin labeled by axonal transport and purified cold insoluble tubulin will be analyzed to determine the biochemical basis of cold stability in axonal microtubules. Particular emphasis will be placed on possible posttranslation modification and differences in microtubule associated proteins. The properties and biological function of cold stable microtubules will be evaluated by examination of the effects of insoluble tubulin on microtubule assembly in vitro. The amount, morphological form, and changes in cold insoluble tubulin in different neurons and regenerating neurites will be evauated biochemically and immunochemically. These studies will provide a better understanding of the roles that tubulin and microtubules play in the function of neurons as well as identifying molecular mechanisms for modulating the properties of neuronal tubulin.