The Yeast Centrosome - Structure Assembly & Function

描述(由申请人提供)：Grant(PPG)将创建一个协作环境，以协调中心体结构、力学、动态平衡和功能的研究。六名研究人员将研究酿酒酵母中心体作为一个类似于脊椎动物中心体的模型微管组织中心(MTOC)，它共享关键的同源成分和调节因子。中心体/SPB是细胞的主要微管组织中心，对两极纺锤体的组装和有丝分裂染色体的准确分离至关重要。中心体复制是一个重要的细胞周期事件，是纺锤体形成的第一步；复制或功能缺陷会导致基因组不稳定和细胞转化。准确的染色体分离依赖于纺锤体组装的适当调节以及纺锤体微管和染色体之间的精确连接。PPG特别关注形成晶格和微管成核位点的10个核心SPB组分，包括Y-微管蛋白复合体。这些蛋白质的作用类似于脊椎动物中心体的中心周围物质，中心体对微管的成核和组织至关重要，但人们对此知之甚少。我们建议阐明酵母中心体的分子结构，并探索其组装、维持和在微管成核中的作用机制。研究这一问题不同方面的多学科方法将被协调起来，以包括：确定Y-微管蛋白复合体和相关蛋白质的结构和机制如何协作完成微管成核；调查SPB核心组件是如何组装的以及它们如何招募Y-微管蛋白复合体；确定维持这种动态细胞器的动态平衡的关键内在和外部因素；解决SPB组件和复合体的原子结构，并致力于整个SPB核心的综合结构模型。这一PPG建立在加州大学旧金山分校的David Agard和华盛顿大学的Trisha Davis在g-微管蛋白复合体方面的现有合作，以及威斯康星州大学的Ivan Rayment和科罗拉多州大学的Mark Winey在SPB核心组件方面的现有合作基础上。这四个小组将共同研究这10种蛋白质。他们的项目将受益于SPB的结构建模(安德烈·萨利，加州大学旧金山分校)和使用生物物理技术量化SPB的机械性能(奇普·阿斯伯里，华盛顿大学)。有巨大的潜力来对中心体进行前所未有的分子描述，揭示组装、稳定性和功能的机制。这项工作将作为未来分析更复杂的人类中心体的模型。

DESCRIPTION (provided by applicant): Grant (PPG) will create a collaborative environment to coordinate research on centrosome structure, mechanics, homeostasis and function. Six investigators will study the Saccharomyces cerevisiae centrosome as a model microtubule-organizing center (MTOC) analogous to the vertebrate centrosome, which shares key homologous components and regulators. A centrosome/SPB is the primary microtubule-organizing center of the cell and is critical for bipolar spindle assembly and accurate mitotic chromosome segregation. Centrosome duplication is an essential cell cycle event being the first step in spindle formation; defects in duplication or function lead to genomic instability and cellular transformation. Accurate chromosome segregation depends on both proper regulation of spindle assembly and precise connections between spindle microtubules and chromosomes. The PPG is focused specifically on 10 core SPB components that form the lattice and microtubule nucleation sites including the y-tubulin complexes. These proteins act similarly to the pericentriolar material of vertebrate centrosomes, which is crucial for microtubule nucleation and organization, but poorly understood. We propose to elucidate the molecular architecture of the yeast centrosome and to probe the mechanisms, by which it is assembled, maintained and functions in nucleating microtubules. A multidisciplinary approach examining different aspects of the problem will be coordinated to include: determining how the structure and mechanics of the y-tubulin complex and associated proteins collaborate to accomplish microtubule nucleation; investigating how core SPB components are assembled and how they recruit y-tubulin complexes; identifying the critical intrinsic and extrinsic factors for maintaining homeostasis of this dynamic organelle; solving the atomic structure of SPB components and complexes, and working toward an integrated structural model of the entire SPB core. This PPG builds on existing collaborations between David Agard (UCSF) and Trisha Davis (U. Washington) on g- tubulin complexes, and Ivan Rayment (U. Wisconsin) and Mark Winey (U. Colorado) on core SPB components. These four groups will work together on the 10 proteins. Their projects will profit from structural modeling of the SPB (Andrej Sali, UCSF) and quantifying the mechanical properties of the SPB using biophysical techniques (Chip Asbury, U. Washington). There is tremendous potential to produce an unprecedented molecular description of a centrosome revealing mechanisms of assembly, stability and function. This work will serve as a model for future analysis of the much more complex human centrosome.