DAAM1 Is a Formin Required for Centrosome Re-Orientation during Cell Migration
DAAM1 Is a Formin Required for Centrosome Re-Orientation during Cell Migration
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DOI：
10.1371/journal.pone.0013064
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发表时间：
2010-09-29
期刊：
影响因子：
3.7
通讯作者：
Manser, Ed
中科院分区：
文献类型：
--
作者：
Ang, Su-Fen;Zhao, Zhuo-shen;Manser, Ed
背景资料：形态发生紊乱相关激活因子1（DAAM 1）是Wnt信号下游的一种抑制剂，对平面细胞极性非常重要。它已被证明在非洲爪蟾和果蝇的胚胎发育过程中促进适当的细胞极化。重要的是，DAAM 1与Disheveled（Dvl）结合，因此在Frizzled受体的下游发挥作用。DAAM 1在哺乳动物细胞中的定位和功能知之甚少。我们在这里调查DAAM 1如何影响培养细胞的迁移和极化，并得出结论，它在中心体polarity.Methodology/主要发现中起着关键作用：使用特异性抗体DAAM 1，我们发现，该蛋白定位到肌动蛋白-肌球蛋白系统和共定位与腹侧肌球蛋白IIB含肌动蛋白应力纤维。这些纤维在亚核区域特别明显。DAAM 1的N-末端区域负责这种靶向，并且DAAM 1（1-440）蛋白可以独立于F-肌动蛋白或RhoA结合与肌球蛋白IIB纤维相互作用。我们还证明，DAAM 1耗竭抑制伤口愈合试验中的高尔基体重定向。伤口边缘细胞表现出非极化细胞迁移特征的多个突起。最后，在U2 OS细胞系稳定表达DAAM 1，我们观察到一个增强的肌球蛋白IIB应力纤维网络，反对cell migration.Conclusions/Significance：这项工作突出了DAAM 1的重要性，在过程中潜在的细胞极性，并表明它的行为部分通过影响肌动蛋白IIB系统的功能。它还强调了DAAM 1的N-末端一半的重要性。DAAM 1耗竭强烈阻断中心体再极化，支持DAAM 1信号传导与已建立的Cdc 42相关极性复合物合作的概念。这些发现也与观察结果一致，即消融肌球蛋白IIB而不是肌球蛋白IIA导致Wnt信号下游的极性缺陷。DAAM 1在培养细胞中的结构-功能分析与发育中胚胎中更复杂的形态学事件平行。
Background: Disheveled-associated activator of morphogenesis 1 (DAAM1) is a formin acting downstream of Wnt signaling that is important for planar cell polarity. It has been shown to promote proper cell polarization during embryonic development in both Xenopus and Drosophila. Importantly, DAAM1 binds to Disheveled (Dvl) and thus functions downstream of the Frizzled receptors. Little is known of how DAAM1 is localized and functions in mammalian cells. We investigate here how DAAM1 affects migration and polarization of cultured cells and conclude that it plays a key role in centrosome polarity.Methodology/Principal Findings: Using a specific antibody to DAAM1, we find that the protein localizes to the acto-myosin system and co-localizes with ventral myosin IIB-containing actin stress fibers. These fibers are particularly evident in the sub-nuclear region. An N-terminal region of DAAM1 is responsible for this targeting and the DAAM1(1-440) protein can interact with myosin IIB fibers independently of either F-actin or RhoA binding. We also demonstrate that DAAM1 depletion inhibits Golgi reorientation in wound healing assays. Wound-edge cells exhibit multiple protrusions characteristic of unpolarized cell migration. Finally, in U2OS cells lines stably expressing DAAM1, we observe an enhanced myosin IIB stress fiber network which opposes cell migration.Conclusions/Significance: This work highlights the importance of DAAM1 in processes underlying cell polarity and suggests that it acts in part by affecting the function of acto-myosin IIB system. It also emphasizes the importance of the N-terminal half of DAAM1. DAAM1 depletion strongly blocks centrosomal re-polarization, supporting the concept that DAAM1 signaling cooperates with the established Cdc42 associated polarity complex. These findings are also consistent with the observation that ablation of myosin IIB but not myosin IIA results in polarity defects downstream of Wnt signaling. The structure-function analysis of DAAM1 in cultured cells parallels more complex morphological events in the developing embryo.