RhoA Regulates Calcium-Independent Periodic Contractions of the Cell Cortex
RhoA Regulates Calcium-Independent Periodic Contractions of the Cell Cortex
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DOI：
10.1016/j.bpj.2010.06.010
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发表时间：
2010-08-18
影响因子：
3.4
通讯作者：
Jacobson, Ken
中科院分区：
文献类型：
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作者：
Costigliola, Nancy;Kapustina, Maryna T.;Jacobson, Ken
当微管在铺展的细胞中解聚时，它们经历了大约一分钟的形态振荡，表明微丝和微管系统之间的正常相互作用已经显著改变。这个实验系统为开发复杂运动过程的细粒度和粗粒度模型提供了一个试验台，但这样的模型需要通过实验得到充分的信息。使用基于傅里叶变换分析的判据，我们检测到扩展细胞中的自发振荡。然而，微管解聚大大增强了它们的幅度和以单一频率工作的趋势。敲除RhoA和加入RhoA下游效应物的各种抑制剂Rho激酶，可以阻断振荡行为。抑制来自内质网库和细胞外介质的钙流动不会显著影响细胞的振荡能力，表明与Rho相比，钙起着从属的调节作用。我们用光、荧光和电子显微镜表征了振荡细胞的动态结构，显示了振荡细胞的整体形态、f-肌动蛋白和磷酸化肌球蛋白轻链分布以及核的位置和形状是如何动态极化的。这些研究不仅将指导未来的实验，还将为开发振荡过程的精细数学模型提供一个框架。
When microtubules are depolymerized in spreading cells, they experience morphological oscillations characterized by a period of about a minute, indicating that normal interactions between the microfilament and microtubule systems have been significantly altered. This experimental system provides a test bed for the development of both fine- and coarse-grained models of complex motile processes, but such models need to be adequately informed by experiment. Using criteria based on Fourier transform analysis, we detect spontaneous oscillations in spreading cells. However, their amplitude and tendency to operate at a single frequency are greatly enhanced by microtubule depolymerization. Knockdown of RhoA and addition of various inhibitors of the downstream effector of RhoA, Rho kinase, block oscillatory behavior. Inhibiting calcium fluxes from endoplasmic reticulum stores and from the extracellular medium does not significantly affect the ability of cells to oscillate, indicating that calcium plays a subordinate regulatory role compared to Rho. We characterized the dynamic structure of the oscillating cell by light, fluorescence, and electron microscopy, showing how oscillating cells are dynamically polarized in terms of their overall morphology, f-actin and phosphorylated myosin light chain distribution, and nuclear position and shape. Not only will these studies guide future experiments, they will also provide a framework for the development of refined mathematical models of the oscillatory process.