Cellular control of cortical actin nucleation.
Cellular control of cortical actin nucleation.
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DOI：
10.1016/j.cub.2014.05.069
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发表时间：
2014-07-21
期刊：
影响因子：
--
通讯作者：
Charras G
中科院分区：
文献类型：
--
作者：
Bovellan M;Romeo Y;Biro M;Boden A;Chugh P;Yonis A;Vaghela M;Fritzsche M;Moulding D;Thorogate R;Jégou A;Thrasher AJ;Romet-Lemonne G;Roux PP;Paluch EK;Charras G
可收缩的肌动蛋白皮层是一层薄薄的肌动蛋白、肌球蛋白和肌动蛋白结合蛋白，覆盖在动物细胞膜上。皮层是细胞形状的主要决定因素，在细胞分裂、迁移和组织形态发生中起着重要作用。例如，皮质收缩性在转移细胞的变形虫迁移和分裂过程中起着至关重要的作用，其调节不当可导致非整倍体。尽管它很重要，但我们对皮层的了解很少，即使是使其成核的蛋白质也仍然未知，尽管基于间接证据已经提出了一些候选。在这里，我们使用了两种独立的方法来鉴定皮质肌动蛋白成核子：使用富含皮质的分离泡进行蛋白质组学分析，以及使用定位/小发夹RNA （shRNA）筛选寻找皮质减弱或收缩性改变的表型。这项无偏见的研究表明，两种蛋白质产生了大部分的皮质肌动蛋白：formin mDia1和Arp2/3复合物。每个成核体向皮层贡献了相似数量的f -肌动蛋白，但积累动力学却大不相同。电镜检查显示，每种核子对皮层网络结构的影响不同。mDia1耗竭导致分裂失败，而Arp2/3耗竭则不会。有趣的是，尽管Arp2/3抑制本身不影响分裂，但却增强了mDia1耗竭的作用。我们的研究结果表明，大部分肌动蛋白皮层是由mDia1和Arp2/3成核的，并提出了一种通过调节每个成核子的相对贡献来快速微调皮层结构和力学的机制。由mDia1成核的肌动蛋白比由Arp2/3成核的肌动蛋白积累得更快。mDia1的缺失导致有丝分裂失败，这一效应被Arp2/3抑制所增强。Bovellan等人发现，两种肌动蛋白成核因子，formin mDia1和Arp2/3复合物，产生了膜下皮层f -肌动蛋白的大部分。这些核子具有非常不同的肌动蛋白积累动力学，在皮层肌动蛋白组织中起着不同的作用，它们的消耗不同地影响细胞周期的进展。
The contractile actin cortex is a thin layer of actin, myosin, and actin-binding proteins that subtends the membrane of animal cells. The cortex is the main determinant of cell shape and plays a fundamental role in cell division, migration, and tissue morphogenesis. For example, cortex contractility plays a crucial role in amoeboid migration of metastatic cells and during division, where its misregulation can lead to aneuploidy. Despite its importance, our knowledge of the cortex is poor, and even the proteins nucleating it remain unknown, though a number of candidates have been proposed based on indirect evidence. Here, we used two independent approaches to identify cortical actin nucleators: a proteomic analysis using cortex-rich isolated blebs, and a localization/small hairpin RNA (shRNA) screen searching for phenotypes with a weakened cortex or altered contractility. This unbiased study revealed that two proteins generated the majority of cortical actin: the formin mDia1 and the Arp2/3 complex. Each nucleator contributed a similar amount of F-actin to the cortex but had very different accumulation kinetics. Electron microscopy examination revealed that each nucleator affected cortical network architecture differently. mDia1 depletion led to failure in division, but Arp2/3 depletion did not. Interestingly, despite not affecting division on its own, Arp2/3 inhibition potentiated the effect of mDia1 depletion. Our findings indicate that the bulk of the actin cortex is nucleated by mDia1 and Arp2/3 and suggest a mechanism for rapid fine-tuning of cortex structure and mechanics by adjusting the relative contribution of each nucleator. The Arp2/3 complex and the formin mDia1 nucleate the bulk of cortical F-actin Nucleator depletion alters the cortex ultrastructural organization Actin nucleated by mDia1 accumulates faster than actin nucleated by Arp2/3 mDia1 depletion leads to mitosis failure, an effect potentiated by Arp2/3 inhibition Bovellan et al. show that two actin nucleators, the formin mDia1 and the Arp2/3 complex, generate the bulk of the submembranous cortical F-actin. These nucleators have very different actin accumulation kinetics and play distinct roles in cortical actin organization, and their depletion differentially affects progression through the cell cycle.
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DOI：
10.1083/jcb.200706196
发表时间：
2007-10-08
期刊：
The Journal of cell biology
影响因子：
--
作者：
Quinlan ME;Hilgert S;Bedrossian A;Mullins RD;Kerkhoff E
通讯作者：
Kerkhoff E
DOI：
10.1073/pnas.1207968109
发表时间：
2012-09-04
影响因子：
11.1
作者：
Bergert, Martin;Chandradoss, Stanley D.;Paluch, Ewa
通讯作者：
Paluch, Ewa
影响因子：
64.8
作者：
Mayer, Mirjam;Depken, Martin;Grill, Stephan W.
通讯作者：
Grill, Stephan W.
影响因子：
2.9
作者：
Biro，Mate;Romeo，Yves;Paluch，Ewa K.
通讯作者：
Paluch，Ewa K.
影响因子：
3.7
作者：
Ang, Su-Fen;Zhao, Zhuo-shen;Manser, Ed
通讯作者：
Manser, Ed