Mechanism of filament nucleation and branch stability revealed by the structure of the Arp2/3 complex at actin branch junctions.
Mechanism of filament nucleation and branch stability revealed by the structure of the Arp2/3 complex at actin branch junctions.
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DOI：
10.1371/journal.pbio.0030383
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发表时间：
2005-11
期刊：
影响因子：
9.8
通讯作者：
Hanein D
中科院分区：
文献类型：
--
作者：
Egile C;Rouiller I;Xu XP;Volkmann N;Li R;Hanein D
肌动蛋白分支连接是保守的细胞骨架元件，在肌动蛋白聚合驱动的细胞运动过程中对产生突出力至关重要。肌动蛋白分支连接的组装需要Arp2/3复合体在激活时从现有的(母)细丝一侧发起一个新的肌动蛋白(子)细丝分支，导致形成树状肌动蛋白网络，快速生长的(带刺的)末端面向运动方向。利用遗传标记和电子显微镜，我们以1纳米的精度确定了体外组装的肌动蛋白分支连接的结构组织。我们在这里表明，除Cortactin外，Arp2/3复合体的激活剂在分支形成后解离。Arp2/3复合体通过一个全面的相互作用网络与母丝结合，复合体的长轴几乎垂直于母丝。肌动蛋白相关蛋白Arp2和Arp3位于其带刺末端朝向子丝生长的方向。这个亚基图谱为肌动蛋白分支连接的组装和机械稳定性的机制带来了直接的结构洞察。用遗传标记和电子显微镜观察肌动蛋白在体外组装的分支连接。获得的亚基图谱为这些保守的细胞骨架元件的组装提供了洞察力。
Actin branch junctions are conserved cytoskeletal elements critical for the generation of protrusive force during actin polymerization-driven cellular motility. Assembly of actin branch junctions requires the Arp2/3 complex, upon activation, to initiate a new actin (daughter) filament branch from the side of an existing (mother) filament, leading to the formation of a dendritic actin network with the fast growing (barbed) ends facing the direction of movement. Using genetic labeling and electron microscopy, we have determined the structural organization of actin branch junctions assembled in vitro with 1-nm precision. We show here that the activators of the Arp2/3 complex, except cortactin, dissociate after branch formation. The Arp2/3 complex associates with the mother filament through a comprehensive network of interactions, with the long axis of the complex aligned nearly perpendicular to the mother filament. The actin-related proteins, Arp2 and Arp3, are positioned with their barbed ends facing the direction of daughter filament growth. This subunit map brings direct structural insights into the mechanism of assembly and mechanical stability of actin branch junctions. Genetic labeling and electron microscopy were used to examine actin branch junctions assembled in vitro. The subunit map obtained offers insights into the assembly of these conserved cytoskeletal elements.
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影响因子：
21.3
作者：
Amann, KJ;Pollard, TD
通讯作者：
Pollard, TD
影响因子：
56.9
作者：
Otterbein, LR;Graceffa, P;Dominguez, R
通讯作者：
Dominguez, R
影响因子：
21.3
作者：
Pantaloni, D;Boujemaa, R;Carlier, MF
通讯作者：
Carlier, MF
影响因子：
3.3
作者：
Yarar, D;D'Alessio, JA;Welch, MD
通讯作者：
Welch, MD
DOI：
10.1083/jcb.146.6.1319
发表时间：
1999-09-20
期刊：
The Journal of cell biology
影响因子：
--
作者：
Egile C;Loisel TP;Laurent V;Li R;Pantaloni D;Sansonetti PJ;Carlier MF
通讯作者：
Carlier MF