Control of axonal sprouting and dendrite branching by the Nrg-Ank complex at the neuron-glia interface
Control of axonal sprouting and dendrite branching by the Nrg-Ank complex at the neuron-glia interface
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DOI：
10.1016/j.cub.2006.06.061
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发表时间：
2006-08-22
期刊：
影响因子：
9.2
通讯作者：
Uemura, Tadashi
中科院分区：
文献类型：
--
作者：
Yamamoto, Misato;Ueda, Ryu;Uemura, Tadashi
神经元是高度极化的细胞，具有不同的亚细胞区室，包括树突状乔木和轴突。神经系统的正常功能不仅依赖于轴突的正确靶向，还依赖于树突状乔木的神经元类特异性几何形状的发育[1-4]。为了研究体内树突树形成的细胞间控制，我们寻找果蝇树突状树枝化（da）神经元表达的细胞表面蛋白[5-7]。其中之一是神经胶质细胞（Nrg），它是IG超家族的成员[8]; Nrg和脊椎动物L1家族分子涉及神经元布线的各个方面，如轴突导向、轴突髓鞘形成和突触形成[9-12]。在nrg突变胚胎中的一个da神经元亚群表现出畸形的树突和异常的轴突发芽。我们的功能分析中的细胞类型选择性的方式强烈建议，这些DA神经元采用NRG与周围的胶质细胞抑制轴突发芽，形成二级树突状分支。至少对于前一种作用，Nrg与细胞内衔接蛋白Ankyrin（Ank）协同作用[13]。因此，Nrg介导的神经元-胶质细胞相互作用，在某些情况下与Ank一起，有助于轴突和树突的形态发生。
Neurons are highly polarized cells with distinct subcellular compartments, including dendritic arbors and an axon. The proper function of the nervous system relies not only on correct targeting of axons, but also on development of neuronal-class-specific geometry of dendritic arbors [1-4]. To study the intercellular control of the shaping of dendritic trees in vivo, we searched for cell-surface proteins expressed by Drosophila dendritic arborization (da) neurons [5-7]. One of them was Neuroglian (Nrg), a member of the Ig superfamily [8]; Nrg and vertebrate L1-family molecules have been implicated in various aspects of neuronal wiring, such as axon guidance, axonal myelination, and synapse formation [9-12]. A subset of the da neurons in nrg mutant embryos exhibited deformed dendritic arbors and abnormal axonal sprouting. Our functional analysis in a cell-type-selective manner strongly suggested that those da neurons employed Nrg to interact with the peripheral glia for suppressing axonal sprouting and for forming second-order dendritic branches. At least for the former role, Nrg functioned in concert with the intracellular adaptor protein Ankyrin (Ank) [13]. Thus, the neuron-glia interaction that is mediated by Nrg, together with Ank under some situations, contributes to axonal and dendritic morphogenesis.