CONTROL OF GENE ACTIVITY AND ORGANELLE BIOGENESIS

微管在真核细胞中普遍存在，在那里它们形成各种各样的微管。 细胞器参与细胞形态、细胞运动、细胞内 运动、有丝分裂和减数分裂。在最精致的微管中 细胞器是纤毛和鞭毛，在人类体内，发现于 呼吸道和女性生殖道、高密度组织 癌症发病率。纤毛功能障碍可导致呼吸系统和 生育问题。这项提议的长期目标是 了解微管多样性背后的分子机制， 特别强调纤毛的生物发生和功能。 关于微管蛋白初级序列作用的假设， 翻译后修饰、微管组织中心和 微管相关蛋白在产生微管多样性中的作用 接受测试。低等真核生物，嗜热四膜虫，被用作 模特。该系统的优点包括相对较小的微管 多基因超家族与质量分析方法的最新进展 体细胞核和生发核的转化使基因替换 和基因破坏。这些方法将用于详细的 α-微管蛋白、β-微管蛋白和γ-微管蛋白功能的突变分析 以及他们的二次修改。一种新的功能 发现的、异常多样的β-微管蛋白将被分析。基因 编码影响微管的微管相关蛋白 体内稳定性将被克隆、测序及其蛋白质产物 将被描述为。这些研究不仅应该阐明 正常纤毛的生物发生和微管蛋白的功能 细胞骨架功能和细胞分裂之间的相互关系， 对正常发展至关重要且经常发生的事件 肿瘤细胞异常。

Microtubules are ubiquitous in eukaryotic cells where they form diverse organelles involved in cell shape, cell motility, intracellular movements mitosis and meiosis. Among the most elaborate microtublar organelles are cilia and flagella, which, in humans, are found in the respiratory tract and the female reproductive tract, tissues with high incidences of cancer. Ciliary dysfunction can cause respiratory and fertility problems. The long term goals of this proposal are to understand the molecular mechanisms underlying microtubule diversity, with particular emphasis on the biogenesis and function of cilia. Hypotheses concerning the role of tubulin primary sequences, posttranslational modifications, microtubule organizing centers and microtubule-associated proteins in generating microtubule diversity will be tested. The lower eukaryote, Tetrahymena thermophila, is used as a model. Advantages of this system include the relatively small tubulin multigene superfamily and the recent development of methods for mass transformation of somatic and germinal nuclei enabling gene replacement and gene disruption. These methods will be used for a detailed mutagenic analysis of the function of alpha-and-beta-and gamma-tubulin and of their secondary modifications. The function of a newly discovered, unusually diverse beta-tubulin will be analyzed. Genes encoding microtubule associated proteins that affect microtubule stability in vivo will be clones, sequenced and their protein products will be characterized. These studies should not only shed light on normal cilia biogenesis and the function of tubulins, but also on interrelationships between cytoskeletal functions and cell division, events that are critical for normal development and that are frequently abnormal in neoplastic cells.