Structural changes in the actin filament associated with tension sensing

与张力感应相关的肌动蛋白丝的结构变化

• 批准号: 23612003
• 负责人: TATSUMI Hitoshi
• 金额: $ 3.49万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2011
• 资助国家: 日本
• 起止时间: 2011 至 2013
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-23612003/
• 关键词: アクチン; コフィリン; 力学刺激; 切断; 光ピンセット; 一分子イメージング; 分子ゆらぎ; 近接場光; アクチン線維; 力受容; イメージング; 一分子操作; 分子ねじれ; ゆらぎ; mechanosensor; cofilin; actin

Molecular and biophysical mechanisms, including how mechanical forces are sensed, are totally unknown. ADF/cofilin proteins are the most preferable candidate for the stress fiber disassembly induced by tension decline in the fiber. Here, we propose a hypothesis that tension in an actin filament prevents the filament from being severed by cofilin. To test this, we prepared single actin filaments tensed with optical tweezers. When the fiber was tensed, it was severed after the application of cofilin with a significantly larger delay in comparison with the control filaments. Direct measurement of the torsional fluctuation of a single actin filament was made under different stresses, which indicated that the standard deviation of the fluctuation was reduced by an applied force of ca. 5 pN. These results demonstrate that tension in the actin filament reduces the binding of cofilin, resulting in a decrease in the effective severing activity of cofilin.

分子和生物物理机制，包括机械力是如何被感知的，都是完全未知的。ADF/cofilin蛋白是由纤维张力下降引起的应力纤维断裂的最佳候选蛋白。在这里，我们提出了一个假设，即肌动蛋白丝中的张力可以防止丝被cofilin切断。为了验证这一点，我们制备了用光学镊子拉紧的单个肌动蛋白丝。当纤维被拉紧时，与对照丝相比，应用cofilin后纤维被切断的延迟明显更大。在不同的应力下，对单个肌动蛋白丝的扭转波动进行了直接测量，结果表明，施加约5 pN的力可以减小波动的标准差。这些结果表明，肌动蛋白丝的张力降低了cofilin的结合，导致cofilin的有效切断活性降低。

项目成果

Mechanosensitive channels are activated by stress in the actin stress fibers, which could be involved in gravity sensing in plants

机械敏感通道由肌动蛋白应力纤维中的应力激活，这可能参与植物的重力感应

• DOI: 10.1111/plb.12095
• 发表时间: 2014
• 期刊: Plant Biology
• 影响因子: 3.9
• 作者: Hitoshi Tatsumi;Takuya Furuichi;Masataka Nakano;Masatsugu Toyota;Kimihide Hayakawa;Masahiro Sokabe;and Hidetoshi Iida
• 通讯作者: and Hidetoshi Iida

Real time imaging of enhanced cofilin dependent actin filament severing by actin interacting protein 1 (AIP1)

肌动蛋白相互作用蛋白 1 (AIP1) 增强肌丝蛋白丝切蛋白依赖性肌动蛋白丝切断的实时成像

• 发表时间: 2013
• 作者: Carina Sekiguchi;Kimihide Hayakawa;Shoichiro Ono; Masahiro Sokabe;and Hitoshi Tatsumi
• 通讯作者: and Hitoshi Tatsumi

Force- and Ca2+-dependent internalization of integrin in cultured endothelial cells

培养内皮细胞中整合素的力和 Ca2 依赖性内化

• 发表时间: 2011
• 期刊: J. Cell Science
• 作者: Kiyoshima D;Kawakami K;Hayakawa K;Tatsumi H and Sokabe M.
• 通讯作者: Tatsumi H and Sokabe M.

DIRECT MEASUREMENT OF THERMODYNAMIC PARAMETERS OF COFILIN-ACTIN FILAMENT INTERACTIONS AT THE SINGLE MOLECULE LEVEL

单分子水平直接测量丝切蛋白-肌动蛋白丝相互作用的热力学参数

• 发表时间: 2014
• 作者: Kimihide Hayakawa1;Shotaro Sakakibara2;Hitoshi Tatsumi2;Masahiro Sokabe1
• 通讯作者: Masahiro Sokabe1

Actin filaments function as a tension sensor by tension-dependent binding of cofilin to the filament.

• DOI: 10.1083/jcb.201102039
• 发表时间: 2011-11-28
• 期刊: The Journal of cell biology
• 作者: Hayakawa K;Tatsumi H;Sokabe M
• 通讯作者: Sokabe M