The Mechanism of Spindle Assembly and Chromosome Alignment

摘要 通过分析纺锤体基质蛋白质组，我们在以前的资助期间定义，我们有 提出了一些令人兴奋的观察结果。最重要的是，我们已经证明， BuGZ蛋白在体外通过相变或凝聚作用发生寡聚化，形成液滴 部分由BuGZ内在无序区中发现的疏水残基介导。的 BuGZ的凝聚活性对于纺锤体及其基质的组装是必不可少的。BuGZ体外凝聚 作为纯蛋白或在纺锤体基质中浓缩微管蛋白并促进MT组装和成束。我们 已发表和未发表的研究结果表明，BuGZ和另一种药物的相互作用和/或凝聚作用， 主轴组装因子TPX 2促进主轴组装。在这里，我们建议使用生物物理，生物化学， 和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活化、微管组装和激动素-微管相互作用， 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 Our published and unpublished findings suggest that the interaction and/or coacervation of BuGZ and another spindle assembly factor, TPX2, promotes spindle assembly.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.