Helical rotation of the diaphanous-related formin mDia1 generates actin filaments resistant to cofilin.
Helical rotation of the diaphanous-related formin mDia1 generates actin filaments resistant to cofilin.
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DOI：
10.1073/pnas.1803415115
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发表时间：
2018-05-29
影响因子：
11.1
通讯作者：
Watanabe N
中科院分区：
文献类型：
--
作者：
Mizuno H;Tanaka K;Yamashiro S;Narita A;Watanabe N
肌动蛋白聚合和解聚活动如何协同控制多种肌动蛋白动力学仍然不清楚。在肌动蛋白进行性延伸过程中，形成蛋白沿着F-肌动蛋白的长螺距螺旋沿着旋转（螺旋旋转），这可能会以与cofilin诱导的扭曲相反的方向扭曲F-肌动蛋白。在这项研究中，我们表明，哺乳动物的madia 1产生的F-肌动蛋白抗cofilin。在EM分析中，从固定的mDia 1延伸的拴系的F-肌动蛋白包含较少的扭曲部分，并表现出对cofilin切割活性的抗性。在细胞中，过表达一个活跃的mDia 1突变体，它含有N-末端调节结构域，延长F-肌动蛋白的寿命和加速cofilin的解离。因此，螺旋旋转的formin可能有助于形成稳定的F-肌动蛋白抵抗肌动蛋白切割活动的cofilin。肌动蛋白调节蛋白之间复杂的相互作用促进了不同细胞肌动蛋白结构的形成。形成蛋白同源蛋白（形成蛋白）在肌动蛋白应力纤维和酵母肌动蛋白电缆的形成中发挥重要作用，主要的肌动蛋白解聚因子cofilin几乎没有关联。在体外，用cofilin修饰的F-肌动蛋白表现出明显的丝扭曲增加。另一方面，在进行性肌动蛋白伸长（螺旋旋转）过程中，哺乳动物的肌动蛋白直径1沿着长节距肌动蛋白螺旋旋转。螺旋旋转可以在与cofilin诱导的扭转相反的方向上对F-肌动蛋白施加扭转力。在这里，我们表明，螺旋旋转的mDia 1转换F-肌动蛋白耐cofilin在体内和体外。没有旋转自由的mDia 1组装的F-肌动蛋白比自由旋转的F-肌动蛋白更能抵抗cofilin的切割和结合活性。电子显微镜分析显示解扭的长螺距螺旋F-肌动蛋白从mDia 1上的mDia 1和尖端侧的细丝的拴系延长。在细胞中，mDia 1 ΔC63（一种含有N端调控结构域的激活突变体）的单分子比自抑制野生型mDia 1和缺乏N端结构域的mDia 1更频繁地显示出与细胞结构的束缚。过表达mDia 1 ΔC63可诱导F-actin的形成，从而延长cofilin的寿命，加速cofilin的解离。因此，formin的螺旋旋转可以作为一种F-肌动蛋白稳定机制，通过这种机制，末端有倒刺的分子可以在很长的范围内增强细丝的稳定性。
It remains obscure how actin polymerizing and depolymerizing activities cooperate to control diverse actin dynamics. Formins rotate along the long-pitch helix of F-actin during processive actin elongation (helical rotation), which may twist F-actin in the opposite direction of the cofilin-induced twisting. In this study, we show that a mammalian formin mDia1 generates F-actin resistant to cofilin. Tethered F-actin elongating from immobilized mDia1 contained a less twisted portion in EM analysis and exhibited resistance to the severing activity of cofilin. In cells, overexpression of an active mDia1 mutant, which harbors N-terminal regulatory domains, prolonged F-actin lifetime and accelerated dissociation of cofilin. Helical rotation of formins may thus facilitate the formation of stabilized F-actin resistant to actin severing activities of cofilin. The complex interplay between actin regulatory proteins facilitates the formation of diverse cellular actin structures. Formin homology proteins (formins) play an essential role in the formation of actin stress fibers and yeast actin cables, to which the major actin depolymerizing factor cofilin barely associates. In vitro, F-actin decorated with cofilin exhibits a marked increase in the filament twist. On the other hand, a mammalian formin mDia1 rotates along the long-pitch actin helix during processive actin elongation (helical rotation). Helical rotation may impose torsional force on F-actin in the opposite direction of the cofilin-induced twisting. Here, we show that helical rotation of mDia1 converts F-actin resistant to cofilin both in vivo and in vitro. F-actin assembled by mDia1 without rotational freedom became more resistant to the severing and binding activities of cofilin than freely rotatable F-actin. Electron micrographic analysis revealed untwisting of the long-pitch helix of F-actin elongating from mDia1 on tethering of both mDia1 and the pointed end side of the filament. In cells, single molecules of mDia1ΔC63, an activated mutant containing N-terminal regulatory domains, showed tethering to cell structures more frequently than autoinhibited wild-type mDia1 and mDia1 devoid of N-terminal domains. Overexpression of mDia1ΔC63 induced the formation of F-actin, which has prolonged lifetime and accelerates dissociation of cofilin. Helical rotation of formins may thus serve as an F-actin stabilizing mechanism by which a barbed end-bound molecule can enhance the stability of a filament over a long range.
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acanthamoeba castellanii的肌动蛋白丝的肌动蛋白丝的表征。
DOI：
10.1083/jcb.115.6.1611
发表时间：
1991-12
期刊：
The Journal of cell biology
影响因子：
--
作者：
Maciver SK;Zot HG;Pollard TD
通讯作者：
Pollard TD
影响因子：
4.8
作者：
Kureishi, Y;Kobayashi, S;Ito, M
通讯作者：
Ito, M
影响因子：
16
作者：
Andrianantoandro, Ernesto;Pollard, Thomas D.
通讯作者：
Pollard, Thomas D.
影响因子：
3.5
作者：
Ishizaki, T;Naito, M;Narumiya, S
通讯作者：
Narumiya, S
影响因子：
9.2
作者：
Michelot, Alphee;Berro, Julien;Blanchoin, Laurent
通讯作者：
Blanchoin, Laurent