在分子分辨率下,微管的组装动态
Jacob W J Kerssemakers1, E Laura Munteanu, Liedewij Laan
1Foundation for Fundamental Research on Matter (FOM) Institute for Atomic and Molecular Physics (AMOLF), Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
Nature
|June 27, 2006
概括
微管体的生长速度比以前想象的要快,增加了管素的寡合体,而不仅仅是单双体. 蛋白XMAP215显著增强了这种快速的微管组装过程.
科学领域:
- 细胞生物学 细胞生物学
- 生物物理学的生物物理.
- 细胞骨动力学 细胞骨动力学
背景情况:
- 微管是真核细胞中必不可少的动态聚合物.
- 之前的研究测量了平均微管组装速率,缺乏分子细节.
- 驱动微管体生长和收缩的精确分子事件仍然不清楚.
研究的目的:
- 以分子分辨率研究微管组装动态.
- 为了阐明管素寡合体在微管体延长中的作用.
- 为了确定XMAP215对微管体生长动力学的影响.
主要方法:
- 使用光学子用于高分辨率观察单个微管组件.
- 用纳米精度监测微管的长度变化.
主要成果:
- 观察到的瞬间微管长度增加超过了单个管二分体大小.
- 证明小的管素寡合体可以直接添加到生长的微管.
- 显示XMAP215通过促进添加更长的寡合物 (40-60 nm) 来显著增强生长.
结论:
- 微管组装涉及直接添加管类寡合物.
- 通过促进这些寡合物的结合,XMAP215加速了微管的延长.
- 这种分子层面的理解使得研究微管末端结合蛋白 in vivo.
相关概念视频
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Complex microtubule structures are present in resting cells and in dividing cells. In resting cells, they are responsible for maintaining the cellular architecture, tracks for intracellular transport, positioning of organelles, assembly of cilia and flagella. They mediate the bipolar spindle assembly for chromosomal segregation and positioning of the cell division plate in dividing cells. The formation of microtubule complex structures depends on the cell type, cell stage, and cell function.
Microtubule Instability
Microtubules are hollow cylindrical filaments having a diameter of approximately 25 nm and a length that varies from 200 nm to 25 μm. GTP-bound tubulin subunits form αβ-heterodimers for microtubule assembly. These core building blocks interact longitudinally, polymerizing into protofilaments. The protofilaments then interact with one another through lateral bonding forces to form stable cylindrical microtubules. These cylindrical filaments are dynamic as they undergo repeated assembly and...


