Transient localization of the Arp2/3 complex initiates neuronal dendrite branching in vivo
Transient localization of the Arp2/3 complex initiates neuronal dendrite branching in vivo
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DOI：
10.1242/dev.171397
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发表时间：
2019-04-01
期刊：
影响因子：
4.6
通讯作者：
Tavosanis, Gaia
中科院分区：
文献类型：
--
作者：
Stuerner, Tomke;Tatarnikova, Anastasia;Tavosanis, Gaia
神经元树突分支的形成对神经系统的布线和功能至关重要。事实上，树突分支增强了神经元接受野的覆盖范围，并调节了传入刺激的初始处理。在体内，复杂的树突图案是通过一个动态的分支形成、分支伸展和收缩的过程来实现的。分支形成的第一步是产生一个动态的丝状小枝。因此，树突小枝形成的机制对树突的形成至关重要。通过对果蝇幼虫感觉神经元分支过程中肌动蛋白亚细胞定位的体内延时成像，结合遗传分析和电子断层扫描，我们确定在激活子WAVE和小GTPase Racl的控制下，肌动蛋白相关蛋白（Arp） 2/3复合体是参与树突小枝形成起始的主要肌动蛋白成核子。Arp2/3组分的瞬时募集标志着小枝在体内的起始位置。这些数据表明Arp2/3的激活是小枝形成起始的早期枢纽。
The formation of neuronal dendrite branches is fundamental for the wiring and function of the nervous system. Indeed, dendrite branching enhances the coverage of the neuron's receptive field and modulates the initial processing of incoming stimuli. Complex dendrite patterns are achieved in vivo through a dynamic process of de novo branch formation, branch extension and retraction. The first step towards branch formation is the generation of a dynamic filopodium-like branchlet. The mechanisms underlying the initiation of dendrite branchlets are therefore crucial to the shaping of dendrites. Through in vivo time-lapse imaging of the subcellular localization of actin during the process of branching of Drosophila larva sensory neurons, combined with genetic analysis and electron tomography, we have identified the Actin-related protein (Arp) 2/3 complex as the major actin nucleator involved in the initiation of dendrite branchlet formation, under the control of the activator WAVE and of the small GTPase Racl. Transient recruitment of an Arp2/3 component marks the site of branchlet initiation in vivo. These data position the activation of Arp2/3 as an early hub for the initiation of branchlet formation.