Laboratory of Chemistry and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
Cell. 2011 Jun 24;145(7):1062-74. doi: 10.1016/j.cell.2011.05.038.
The microtubule-based metaphase spindle is subjected to forces that act in diverse orientations and over a wide range of timescales. Currently, we cannot explain how this dynamic structure generates and responds to forces while maintaining overall stability, as we have a poor understanding of its micromechanical properties. Here, we combine the use of force-calibrated needles, high-resolution microscopy, and biochemical perturbations to analyze the vertebrate metaphase spindle's timescale- and orientation-dependent viscoelastic properties. We find that spindle viscosity depends on microtubule crosslinking and density. Spindle elasticity can be linked to kinetochore and nonkinetochore microtubule rigidity, and also to spindle pole organization by kinesin-5 and dynein. These data suggest a quantitative model for the micromechanics of this cytoskeletal architecture and provide insight into how structural and functional stability is maintained in the face of forces, such as those that control spindle size and position, and can result from deformations associated with chromosome movement.
基于微管的中期纺锤体受到各种方向和时间尺度的力的作用。目前，我们无法解释这种动态结构如何在保持整体稳定性的同时产生并响应力，因为我们对其微观力学性质的了解还很有限。在这里，我们结合使用力校准针、高分辨率显微镜和生化扰动来分析脊椎动物中期纺锤体的时间尺度和方向依赖性粘弹性性质。我们发现纺锤体的粘性取决于微管的交联和密度。纺锤体的弹性可以与动粒和非动粒微管的刚性相关联，也可以与由 kinesin-5 和 dynein 组成的纺锤体极组织相关联。这些数据为这种细胞骨架结构的微观力学提供了一个定量模型，并深入了解在面对力时如何维持结构和功能的稳定性，例如那些控制纺锤体大小和位置的力，以及与染色体运动相关的变形所产生的力。
