Studies on Microtubule Binding Proteins

描述（由申请人提供）：驱动蛋白沿沿着微管移动或从末端将其解旋。在过去的12年里，我们已经使用冷冻电子显微镜和图像分析来研究这些运动和解聚活动。基于我们的发现，以及许多其他实验室的工作，我们已经概述了设计原则，统一了我们对驱动蛋白和肌球蛋白的思考，并为这两个分子马达超家族的机械理解提供了一个通用框架。我们现在有一个很好的总体了解的核苷酸介导的构象变化的基础进行性，正端定向运动的传统驱动蛋白，非进行性，负端定向运动的驱动蛋白14，和驱动蛋白13介导的解聚的许多方面。微管相关蛋白的其他工作提供了这些蛋白质的选择性微管稳定的机制的见解。我们过去的成果为目前的提案奠定了基础。这里所描述的实验分为两大主题领域。首先，我们描述的实验，将回答我们所看到的驱动蛋白介导的运动和解聚的一些剩余的突出的一般性问题。第二，我们建立在我们的调查地图，扩大这方面的研究计划，并纳入研究微管加末端跟踪蛋白和动粒复合物的微管动力学和染色体微管附件的调制的结构基础。在我们所有的工作中，我们寻求回答基本的生物学问题，我们的发现与健康和疾病状态都有关联。

DESCRIPTION (provided by applicant): Kinesins move along microtubules or depolymerize them from the ends. Over the last 12 years, we have used cryo-electron microscopy and image analysis to investigate these motility and depolymerization activities. Based on our findings, as well as work from many other laboratories, we have outlined design principles that unify our thinking about kinesins and myosins and provide a general framework for a mechanistic understanding of these two superfamilies of molecular motors. We now have a good general understanding of the nucleotide-mediated conformational changes underlying processive, plus-end-directed motion by conventional kinesin, non-processive, minus-end-directed motion by kinesin 14s, and many aspects of kinesin 13-mediated depolymerization. Additional work on microtubule associated proteins has provided insights into the mechanisms of selective microtubule stabilization by these proteins. Our past results set the stage for the current proposal. The experiments described here fall into two broad subject areas. First, we describe experiments that will answer what we see as some of the remaining outstanding general questions about kinesin-mediated motility and depolymerization. Second, we build upon our investigations on MAPs, expanding this aspect of our research program and incorporating studies on microtubule plus-end-tracking proteins and kinetochore complexes to investigate the structural basis for modulation of microtubule dynamics and chromosome-microtubule attachments. In all our work, we seek to answer fundamental biological questions and our findings have relevance for both the healthy and diseased states.