论文标题
流体动力的不稳定性驱动微管上的蛋白液滴形成成核分支
A hydrodynamic instability drives protein droplet formation on microtubules to nucleate branches
论文作者
论文摘要
液 - 液相分离不仅发生在散装液体中，而且在表面上发生。在生理学中，冷凝水在细胞结构上的性质和功能仍未探索。在这里，我们研究了凝结的蛋白TPX2在微管上的表现如何启动分支微管成核，这对于真核细胞中的纺锤体组装至关重要。使用荧光，电子和原子力显微镜和流体动力学理论，我们表明，微管上的TPX2根据雷利 - 普拉托不稳定性进行了重新组织，例如使蜘蛛网的露滴。均匀涂层微管后，TPX2形成了定期间隔的液滴。液滴间距随着较高的TPX2浓度而增加。随机模型表明，液滴通过限制沿着微管的空间来使分支成核更有效，其中多个必要因素共定位以核定A分支。
Liquid-liquid phase separation occurs not only in bulk liquid, but also on surfaces. In physiology, the nature and function of condensates on cellular structures remain unexplored. Here, we study how the condensed protein TPX2 behaves on microtubules to initiate branching microtubule nucleation, which is critical for spindle assembly in eukaryotic cells. Using fluorescence, electron, and atomic force microscopies and hydrodynamic theory, we show that TPX2 on a microtubule reorganizes according to the Rayleigh-Plateau instability, like dew droplets patterning a spider web. After uniformly coating microtubules, TPX2 forms regularly spaced droplets from which branches nucleate. Droplet spacing increases with greater TPX2 concentration. A stochastic model shows that droplets make branching nucleation more efficient by confining the space along the microtubule where multiple necessary factors colocalize to nucleate a branch.
