Control of Gene Activity and Organelle Biogenesis

超出所提供的空间。微管（MTs）在真核细胞中普遍存在，它们形成各种细胞器，参与细胞形状，细胞运动，细胞内运动，有丝分裂和减数分裂。最精细的微管细胞器包括基体和纤毛和鞭毛的轴突，它们在人类的呼吸道、女性生殖道和癌症高发组织中都有发现。纤毛功能障碍会导致呼吸和生育问题。本研究的长期目标是了解微管多样性的分子机制，特别强调纤毛和基体的生物发生和功能。在确定了c_和_小管中特定的“轴突序列”作为糖基化位点之后，我们将确定和表征其他初级序列和小管的翻译后修饰（PTMs）在确定MT细胞器结构和功能方面的功能。低级真核生物，嗜热四膜虫，被用作模型。该系统的优点包括其相对较小的微管蛋白多基因超家族，以及最近发展的体细胞和生发细胞核大规模转化方法，使基因替代和基因破坏成为可能。这些方法将用于对o_-，[5-和_'-微管蛋白及其二次修饰的功能进行详细的诱变分析。新发现的异常多样化的15-微管蛋白靶向特定MT细胞器的机制将被分析。糖基化影响纤毛M-I功能的机制将通过使用遗传和生化方法来鉴定和表征与糖基化微管蛋白特异性相互作用的蛋白质来研究。这些研究应该揭示正常纤毛的生物发生和微管蛋白在产生MT多样性中的功能，这是理解细胞骨架功能所必需的，这些功能对正常发育至关重要，并且在肿瘤细胞中经常异常。网站性能 ======================================== 节结束 ===========================================

EXCEED THE SPACE PROVIDED. Microtubules (MTs) 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 microtubular organelles are basal bodies and the axonemes of cilia and flagella, which, in humans, are found in the respiratory tract, the female reproductive tract, and in 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 and basal bodies. Having identified specific "axonemal sequences" as the sites of glyclylation in both c_ and _ tubulins, we will identify and characterize the function of other primary sequences and post-translational modifications (PTMs) of tubulins in specifying the structure and function of MT organelles. The lower eukaryote, Tetrahymena thermophila, is used as a model. Advantages of this system include its 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 o_-, [5- and _'-tubulin and of their secondary modifications. The mechanisms by which a newly discovered, unusually diverse 15-tubulin is targeted to specific MT organelles will be analyzed. The mechanism by which glycylation affects ciliary M-I" function will be studied by using genetic and biochemical approaches to identify and characterize proteins that interact specifically with glycylated tubulin. These studies should shed light on normal cilia biogenesis and the function of tubulins in generating MT diversity, that are required to understand cytoskeletal functions that are critical for normal development and that are frequently abnormal in neoplastic cells. PERFORMANCE SITE ========================================Section End===========================================