MECHANISMS OF FUNCTIONAL SPECIALIZATION OF MICROTUBULES

描述：这项建议是为了研究后 纤毛虫四膜虫中微管蛋白的翻译修饰 嗜热菌。该项目是基于 首席研究员，当他是博士后研究员时，这允许 同源整合的四膜虫遗传转化研究。两者都有 宏观和微观核转型现在是可能的，允许 基因置换研究基因替换后的表型。四膜虫 拥有一个α微管蛋白基因和两个贝塔微管蛋白基因。这项提议将 检测α-微管蛋白等位基因的表型 被设计成阻止每一个已知的微管蛋白的翻译后 修改。其他工作将寻求目前未知的职位- 翻译修饰(PTM)，以及它们的表型 将对消除进行研究。需要检验的假设是PTMS 与微管蛋白的分化有关，并且对微管蛋白的分化有重要意义。这 这种想法在四膜虫中当然是可信的，因为同样的阿尔法 微管蛋白用于体内几个不同的微管系统。 细胞：纤毛、皮质微管、有丝分裂纺锤体等。 将对纤毛α微管蛋白进行生物化学 四膜虫以确定其他可能对 微管蛋白在这个细胞器中起作用。有人建议，这一分析 将阐明PTMS在微管中的作用 其他真核系统的分化。

DESCRIPTION: This proposal is to study the significance of post- translational modifications of tubulin in the ciliate, Tetrahymena thermophila. The project is based upon a recent achievement by the principal investigator, while he was a postdoctoral fellow, that permits genetic transformation of Tetrahymena by homologous integration. Both macro- and micro-nuclear transformation are now possible, allowing for the study of phenotype following gene replacement. Tetrahymena possesses a single alpha and two beta tubulin genes. This proposal will examine the phenotype of alleles of alpha tubulin that have been engineered to block each of tubulin's known post-translational modifications. Additional work will seek currently unknown post- translational modifications (PTMs), and again, the phenotype of their elimination will be studied. The hypothesis to be tested is that PTMs are associated with and significant for tubulin differentiation. This idea is certainly plausible in Tetrahymena, given that the same alpha tubulin is employed for several distinct microtubule systems within the cell: cilia, cortical microtubules, the mitotic spindle, etc. Biochemistry will be carried out on ciliary alpha tubulins of Tetrahymena to identify additional PTMs that may be important for tubulin function in this organelle. It is proposed that this analysis in Tetrahymena will elucidate the role of PTMs in microtubules differentiation for other eukaryotic systems.