INTRAFLAGELLAR TRANSPORT IN CHLAMYDOMONAS REINHARDTII

莱因衣藻的鞭内运输

• 批准号: 7033161
• 负责人: DOUGLAS GENE COLE
• 金额: $ 20.29万
• 依托单位: UNIVERSITY OF IDAHO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7033161
• 关键词: Chlamydomonas; cell component structure /function; cell cycle; cilium; dynein ATPase; flagellum; genetic library; intracellular transport; kinesin; plant genetics; plant proteins; protein protein interaction; protein purification; protein transport; transposon /insertion element

DESCRIPTION (provided by applicant): Eukaryotic cilia and flagella are ancient cellular appendages that have been adapted for motile and sensory functions. Motile forms of these organelles are capable of propelling some cells like sperm and protozoa through a liquid environment while other cells like the ciliated trachea of man use the coordinated beating of many cilia to propel a liquid or mucous environment over the surface of the cells. Nonmotile cilia have been adapted to sense a wide range of stimuli. Classic examples include the photoreceptors which are highly modified cilia that can sense visible light and the olfactory cilia which are highly enriched in odorant receptors. Because of their important roles in both motility and sensory transduction, defects in cilia and flagella have been intimately linked with a number of human diseases including retinal degeneration, immotilie cilia and Kartagener's syndromes, male and female infertility, hydrocephalus and anosmia, Bardet-Beidl syndrome and 1 of the most common genetic diseases in man, polycystic kidney disease. Focusing on how cells build these organelles, we study intraflagellar transport (IFT) which is required for the assembly and maintenance of these structures. IFT is characterized by the movement of protein particles along the long axis of the organelle, both out to the tip (anterograde IFT driven by kinesin-2) and back to the cell body (retrograde IFT driven by cytoplasmic dynein 1b/2). A primary function of IFT is to transport axonemal building blocks out to the distal tip which serves as the site of assembly for the organelle. The model organism for the study of IFT is the unicellular biflagellate green alga, Chlamydomonas reinhardtii. Biochemical analysis of the 17 proteins found in the Chlamydomonas IFT particles has begun to reveal their complex oligomeric organization. Continuing on our previous study of the IFT particles, our specific aims are: (1) to further characterize the architecture of IFT particles; to identify how the 17 proteins assemble into complexes; (2) to characterize the interaction of the IFT particles with the IFT motor proteins, kinesin-2 and cytoplasmic dynein 1b; (3) to directly visualize the transport of hypothesized IFT cargo including tubulin and radial spoke complexes; and (4) to address the function of separate IFT particle proteins. An important aspect of Aim 4 will involve the creation of 900 or more motility mutants; currently we lack mutants in more than 1/2 of the IFT particle proteins.

描述（由申请人提供）：真核纤毛和鞭毛是古老的细胞附属物，已适应运动和感觉功能。这些细胞器的运动形式能够推动一些细胞（如精子和原生动物）通过液体环境，而其他细胞（如人类的纤毛气管）利用许多纤毛的协调跳动来推动细胞表面的液体或粘液环境。不动的纤毛已经适应了感知各种刺激。典型的例子包括光感受器和嗅觉纤毛，它们是高度修饰的纤毛，可以感知可见光，嗅觉纤毛富含气味受体。由于纤毛和鞭毛在运动和感觉传导中的重要作用，纤毛和鞭毛的缺陷与许多人类疾病密切相关，包括视网膜变性、纤毛不动和卡塔格纳综合征、男性和女性不孕症、脑积水和嗅觉丧失、巴代-贝德尔综合征以及人类最常见的遗传病之一——多囊肾病。我们专注于细胞如何构建这些细胞器，研究组装和维护这些结构所需的鞭毛内运输（IFT）。 IFT 的特点是蛋白质颗粒沿着细胞器的长轴运动，既向外运动至尖端（由驱动蛋白 2 驱动的顺行 IFT），又返回细胞体（由细胞质动力蛋白 1b/2 驱动的逆行 IFT）。 IFT 的主要功能是将轴丝构件运输到远端，作为细胞器的组装部位。 IFT 研究的模式生物是单细胞双鞭毛绿藻莱茵衣藻 (Chlamydomonas Reinhardtii)。对衣藻 IFT 颗粒中发现的 17 种蛋白质的生化分析已开始揭示其复杂的寡聚组织。继续我们之前对IFT粒子的研究，我们的具体目标是：（1）进一步表征IFT粒子的结构；确定 17 种蛋白质如何组装成复合物； (2) 表征 IFT 颗粒与 IFT 运动蛋白、驱动蛋白 2 和细胞质动力蛋白 1b 的相互作用； (3) 直接可视化假设的 IFT 货物的运输，包括微管蛋白和径向辐条复合物； (4) 解决单独的 IFT 颗粒蛋白的功能。目标 4 的一个重要方面将涉及创建 900 个或更多的运动突变体；目前我们超过 1/2 的 IFT 颗粒蛋白缺乏突变体。