Molecular mechanism of the selective recognition of growing microtubule ends by vertebrate +TIPs

脊椎动物TIP选择性识别生长微管末端的分子机制

• 批准号: 85931720
• 负责人: Dr. Thomas Surrey
• 金额: --
• 依托单位: The Francis Crick Institute
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/85931720?language=en
• 关键词: Molecular; mechanism; selective; recognition; growing

The microtubule cytoskeleton is crucial for the internal organization of eukaryotic cells. Several microtubule-associated proteins modulate the dynamics of microtubules and provide a link to chromosomes, membrane organelles or the cell cortex. A subclass of these proteins, the so-called microtubule plus-end binding proteins (+TIPs), have the remarkable property of selectively binding to the growing plus ends of microtubules. These proteins have several essential functions. They are crucial for proper cell division, involved in signalling or responsible for the establishment of cell polarity. Defective forms of these proteins can lead to cancer. The molecular mechanism, however, by which these proteins recognize the dynamic microtubule end and how they affect microtubule dynamics is not understood. This is a result of the complexity of the microtubule plus-end tracking system that consists of several interacting proteins in vivo. Another problem has been that plus-end tracking could not be reconstituted in vitro. Here we will reconstitute with several vertebrate +TIPs dynamic plus-end tracking in vitro. Using biochemical techniques and time-lapse fluorescence microscopy down to the single molecule level, we will analyze quantitatively in a minimal and well-controlled system the molecular interactions and the dynamics underlying the phenomenon of microtubule plus-end tracking. We aim at elucidating how combinatorial effects between mutually interacting +TIPs define the functioning of the multi-component plus-end tracking system at a molecular level. This work will lead to a molecular understanding of the functioning of a dynamic protein interaction network showing complex dynamic behavior.

微管细胞骨架对于真核细胞的内部组织是至关重要的。几种微管相关蛋白调节微管的动态，并提供与染色体、膜细胞器或细胞皮质的联系。这些蛋白质的一个亚类，即所谓的微管正端结合蛋白(+TIPS)，具有选择性地与微管生长的正端结合的显著特性。这些蛋白质有几个基本功能。它们对正常的细胞分裂至关重要，参与信号传递或负责细胞极性的建立。这些蛋白质的缺陷形式可能会导致癌症。然而，这些蛋白质识别动态微管末端的分子机制以及它们如何影响微管动力学尚不清楚。这是由于微管正端跟踪系统的复杂性，该系统由体内几个相互作用的蛋白质组成。另一个问题是，正端跟踪不能在体外重建。在这里，我们将重建几个脊椎动物+末端的动态正端跟踪在体外。利用生化技术和延时荧光显微镜，我们将在一个最小和控制良好的系统中，对微管+末端跟踪现象背后的分子相互作用和动力学进行定量分析。我们的目的是阐明相互作用的+末端之间的组合效应如何在分子水平上定义多组分+末端跟踪系统的功能。这项工作将导致分子理解呈现复杂动态行为的动态蛋白质相互作用网络的功能。