测量增长微管子的力-速度关系
1Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, NJ 07974, USA.
概括
研究人员测量了单个微管在细胞分裂过程中产生的力. 微管的生长在增强力下显著放缓,下降速度比预期的更快.
科学领域:
- 细胞生物学 细胞生物学
- 生物物理学的生物物理.
- 细胞骨的动力学
背景情况:
- 蛋白质聚合驱动细胞运动.
- 微管是基因分裂期间染色体运动的关键.
- 了解微管力是细胞力学的关键.
研究的目的:
- 要量化单个微管所施加的力.
- 为了确定微管力和生长速度之间的关系.
- 将实验结果与微管力学理论模型进行比较.
主要方法:
- 微管在一个端固定在基板上.
- 微管子推向一个微型制造的刚性屏障.
- 分析了微管曲以测量力和生长速度.
主要成果:
- 微管的生长速度从零力时的1.2微米/分钟下降到下午3-4时的0.2微米/分钟.
- 强力-速度关系遵循一个呈指数递减的模式.
- 观察到的力-速度衰变率比理论预测更快.
结论:
- 微管体力产生显著影响生长速度.
- 实验结果与现有的理论模型保持一致,但却偏离现有理论模型.
- 微管聚合理论的进一步细化是有必要的.
相关概念视频
Microtubule Formation
Microtubules are dynamic structures that undergo continuous assembly and disassembly. They originate from specialized multi-protein complexes known as microtubule organizing centers or MTOCs. Within the MTOC, the point of origin of the microtubule is known as the minus end, while the end radiating outward is the plus end. Microtubules serve two primary functions — the organization of spindle complexes to separate sister chromatids during mitotic or meiotic cell division and the formation of...
Destabilization of Microtubules
The destabilization of microtubules can occur during different stages of the microtubule lifecycle, such as nucleation or elongation. It can take place at either end of the microtubule or in the microtubule lattices as a whole. The lifespan of individual microtubules within a cell varies according to the cell type and stage of the cell cycle. During interphase, the lifespan of the microtubule is about 30 minutes, while during cell division, it is about 15 minutes. In axonal microtubules of...
Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
Forces Acting on Chromosomes
During mitosis, chromosome movements occur through the interplay of multiple piconewton level forces. In prometaphase, these forces help in chromosome assembly or congression at the equatorial plane, eventually leading to their alignment at the metaphase plate. The forces acting on the chromosomes are space and time-dependent; therefore, they vary with the position of the chromosomes as the cell progresses through mitosis.
Microtubules and motor proteins exert two types of forces on...
Microtubules and motor proteins exert two types of forces on...
Anaphase A and B
Microtubules form through the end-to-end polymerization of tubulin heterodimers. Kinetochore microtubules originate from the spindle poles, and their plus-ends connect with the kinetochores on sister-chromatids. Ndc80 protein complexes, present on the kinetochore, form low-affinity links with the plus end of these kinetochore microtubules.
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...
Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...


