Actin filaments function as a tension sensor by tension-dependent binding of cofilin to the filament.
Actin filaments function as a tension sensor by tension-dependent binding of cofilin to the filament.
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DOI：
10.1083/jcb.201102039
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发表时间：
2011-11-28
期刊：
影响因子：
--
通讯作者：
Sokabe M
中科院分区：
文献类型：
--
作者：
Hayakawa K;Tatsumi H;Sokabe M
在体外，肌动蛋白丝张力与粘附性切断蛋白cofilin的结合和表观活性相关，这表明细胞对机械力变化做出反应的分子机制。细胞内外的机械力影响肌动蛋白细胞骨架的结构和动力学。然而，基本的分子和生物物理机制，包括机械力是如何感知的，在很大程度上是未知的。肌动蛋白解聚因子/cofilin蛋白是一种广泛存在于真核生物中的肌动蛋白调节蛋白，是最有可能在纤维张力变化时驱动应力纤维解体的蛋白质。在这项研究中，我们提出了一个新的假设，在肌动蛋白丝的张力防止丝被切断cofilin。为了测试这一点，我们使用光镊将单个肌动蛋白丝置于张力下。当纤维被拉紧时，与悬浮在溶液中的对照细丝相比，在应用cofilin后纤维被切断，延迟显著更大。当肌动蛋白束被拉紧时，cofilin与肌动蛋白束的结合率降低。这些结果表明，在肌动蛋白丝的张力减少了cofilin的结合，导致其有效的切断活性的降低。
In vitro, actin filament tension correlates with the binding and apparent activity of the filament-severing protein cofilin, suggesting a molecular mechanism by which cells respond to changes in mechanical force. Intracellular and extracellular mechanical forces affect the structure and dynamics of the actin cytoskeleton. However, the underlying molecular and biophysical mechanisms, including how mechanical forces are sensed, are largely unknown. Actin-depolymerizing factor/cofilin proteins are actin-modulating proteins that are ubiquitously distributed in eukaryotes, and they are the most likely candidate as proteins to drive stress fiber disassembly in response to changes in tension in the fiber. In this study, we propose a novel hypothesis that tension in an actin filament prevents the filament from being severed by cofilin. To test this, we placed single actin filaments under tension using optical tweezers. When a fiber was tensed, it was severed after the application of cofilin with a significantly larger delay in comparison with control filaments suspended in solution. The binding rate of cofilin to an actin bundle decreased when the bundle was tensed. These results suggest that tension in an actin filament reduces the cofilin binding, resulting in a decrease in its effective severing activity.
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影响因子：
5.6
作者：
HUXLEY, HE;BROWN, W
通讯作者：
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影响因子：
16
作者：
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DOI：
10.1073/pnas.94.3.849
发表时间：
1997-02-04
影响因子：
11.1
作者：
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通讯作者：
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影响因子：
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通讯作者：
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1.5
作者：
Ono, S;Abe, H;Obinata, T
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