The Mechanism of Spindle Assembly and Chromosome Alignment

摘要 通过分析我们在之前的资助期中定义的纺锤体基质蛋白质组，我们得到了 做了许多令人兴奋的观察。最重要的是，我们已经证明了主轴矩阵 蛋白质BuGZ在体外通过相变或凝聚形成液滴进行齐聚 部分由BuGZ固有无序区中发现的疏水残基介导。这个 BuGZ的凝聚活性是主轴与其基质组装所必需的。补肾活血方的体外凝聚作用 作为纯蛋白质或在纺锤体基质中，浓缩微管蛋白并促进MT的组装和捆绑。我们的 已发表和未发表的研究结果表明，BuGZ和另一种 主轴装配系数TPX2可促进主轴装配。在这里，我们建议使用生物物理、生化、 以及细胞生物学方法来剖析这些纺锤体组装因子的分子机制 协同调节Aurora A激活、微管组装和动粒-微管相互作用 有丝分裂。

ABSTRACT Through analyzing the spindle matrix proteome, which we defined in our previous funding periods, we have made a number of exciting observations. Most importantly we have demonstrated that the spindle matrix protein, BuGZ, undergoes oligomerization via phase transition or coacervation to form liquid droplets in vitro mediated in part by the hydrophobic residues found in the intrinsically disorder region of BuGZ. The coacervation activity of BuGZ is essential for assembly of the spindle and its matrix. BuGZ coacervation in vitro as pure protein or in the spindle matrix concentrates tubulin and promotes MT assembly and bundling. Our published and unpublished findings suggest that the interaction and/or coacervation of BuGZ and another spindle assembly factor, TPX2, promotes spindle assembly. Here we propose to use biophysical, biochemical, and cell biological approaches to dissect the molecular mechanism by which these spindle assembly factors synergize to regulate Aurora A activation, microtubule assembly, and kinetochore-microtubule interactions in mitosis.