The Yeast Centrosome - Structure Assembly & Function

描述（由申请人提供）：赠款（PPG）将创建一个协作环境，以协调中心体结构，力学，稳态和功能的研究。六名研究人员将研究酿酒酵母中心体作为类似于脊椎动物中心体的微管组织中心（MTOC）模型，它们具有关键的同源成分和调控因子。中心体/SPB是细胞的主要微管组织中心，对双极纺锤体组装和有丝分裂染色体的精确分离至关重要。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正确调节和纺锤体微管与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-微管蛋白复合物。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，对微管成核和组织至关重要，但人们对其知之甚少。我们建议阐明酵母中心体的分子结构，并探讨其在微管成核中组装、维持和功能的机制。一个多学科的方法检查问题的不同方面将协调包括：确定y-微管蛋白复合物和相关蛋白的结构和机制如何协同完成微管成核；研究SPB核心组分如何组装以及它们如何招募γ-微管蛋白复合物；识别维持这一动态细胞器稳态的关键内在和外在因素；求解SPB组分和配合物的原子结构，并致力于建立整个SPB核心的集成结构模型。该PPG建立在David Agard （UCSF）和Trisha Davis （U. Washington）在g-微管蛋白复合物上的现有合作，以及Ivan Rayment （U. Wisconsin）和Mark Winey （U. Colorado）在核心SPB组件上的合作基础上。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（Andrej Sali， UCSF）和使用生物物理技术量化SPB的机械特性（Chip Asbury， U. Washington）。对中心体进行前所未有的分子描述，揭示其组装、稳定性和功能的机制，具有巨大的潜力。这项工作将作为未来分析更复杂的人类中心体的一个模型。

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 γ-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.