3D STRUCTURE OF MITOTIC MICROTUBULES

有丝分裂微管的 3D 结构

• 批准号: 3568432
• 负责人: JOHN M. MURRAY
• 金额: $ 9.47万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 1996-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3568432
• 关键词: computer simulation; electron microscopy; gel electrophoresis; high performance liquid chromatography; mathematical model; microtubules; molecular shape; sea urchins

Microtubules are engaged in many important activities in eukaryotic cells. They form the scaffolding that helps determine overall cell shape, as well as the arrangement of interior organelles. Intracellular communication and the traffic of vesicles depend upon the microtubule network. In dividing cells, the microtubules cycle between the generalized multifunctional interphase network that provides access to every corner of the cell, and a mitotic apparatus that is centrally located and specialized for the task of separating chromosomes. As would be expected for such a heavily used object, agents that interfere with microtubule function strike at the heart of many cellular activities and often have profound physiological effects. Some of these agents have therapeutic applications in humans: colchicine, used for its anti-inflammatory properties in gouty arthritis; vincristine, vinblastine, and taxol, used for their anti-mitotic effects against a variety of neoplasms; griseofulvin, an anti-fungal agent; and others. Besides these medicinal uses, agents that affect microtubules are significant for human health in equally important, though non-therapeutic ways, such as their widespread use as pesticides and fungicides. Basic information about microtubules therefore has an unusually direct and immediate connection to the mission of the NIH. As expected from their diverse activities, microtubules interact with many other cellular proteins. To understand these interactions in a way that will allow rational manipulation of microtubule-based phenomena, which would certainly be a potent therapeutic and diagnostic capability, we must know the structure of microtubules in great detail. We must also know the structure of the supramolecular assemblies that use microtubules to provide the motion-producing, shape-determining, and organelle-positioning functions within cells. Fortunately, and remarkably, the basic structure of the microtubule seems to be constant regardless of the particular assembly in which it is involved. Thus if we can determine the structure of any one of the functional classes of microtubule, we will have learned a lot about all microtubules. This proposal describes our successful preparation of native cellular microtubules suitable for structure determination by cryo-electron microscopy of unfixed, unstained, frozen hydrated samples. We report some preliminary results from examining these microtubules by cryo-electron microscopy, and propose a set of experiments that will yield a high resolution 3D structure of the native microtubule.

微管从事真核细胞中的许多重要活动。 它们形成脚手架，有助于确定整体细胞形状 作为内部细胞器的布置。细胞内沟通和 囊泡的流量取决于微管网络。在分裂 细胞，微管在广义多功能之间循环 相间网络，可访问单元格的每个角落，并且 丝裂设备，位于中心且专门用于任务 分离染色体。正如如此大量使用的那样 对象，干扰微管功能在 许多细胞活动的心脏，通常具有深刻的生理 效果。这些代理中的一些在人类中具有治疗应用： 秋水仙碱，用于痛风关节炎中的抗炎特性； 长春新碱，文素和紫杉醇用于其抗隔离作用 反对各种肿瘤； Griseofulvin，抗真菌剂；和 其他的。除了这些药用外，影响微管的药物是 对人类健康对同样重要的人类健康意义很重要，尽管非治疗性 方法，例如它们广泛用作农药和杀菌剂。基本的 因此，有关微管的信息具有异常直接的 与NIH任务的直接联系。 正如他们从各种活动中预期的那样，微管与许多人相互作用 其他细胞蛋白。以某种方式理解这些互动 将允许对基于微管的现象进行合理操纵，这 肯定是一种有效的治疗和诊断能力，我们必须 非常详细地了解微管的结构。我们还必须知道 使用微管的超分子组件的结构 提供运动产生，确定形状和细胞器位置 细胞内的功能。幸运的是，值得注意的是基本结构 微管似乎是恒定的 它参与其中的组装。因此，如果我们可以确定结构 在微管的任何功能类别中，我们都会学会 关于所有微管的很多。 该建议描述了我们成功准备天然细胞的准备 微管适合通过冷冻电子测定的结构 未固定，未染色的冷冻水合样品的显微镜。我们报告一些 通过冷冻电子检查这些微管的初步结果 显微镜，并提出了一组将产生高的实验 本机微管的分辨率3D结构。