Signaling Networks in Neuronal Polarization
Signaling Networks in Neuronal Polarization
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DOI：
10.1523/jneurosci.3824-06.2006
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发表时间：
2006-10
期刊：
影响因子：
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通讯作者：
Takeshi Yoshimura;N. Arimura;K. Kaibuchi
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文献类型：
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作者：
Takeshi Yoshimura;N. Arimura;K. Kaibuchi
一个成熟的神经元在结构和功能上都是典型的极化，有一个长轴突和几个树突。神经元极性是信号从体细胞或树突向轴突单向流动的必要条件。建立极化神经元的初始事件是单个轴突的指定。在神经元发育早期，一个未成熟的神经突与其他神经突分化形成轴突。虽然过去二十年的研究已经产生了轴突和树突之间结构、分子和功能差异的目录，但我们现在才开始了解神经元极性建立的分子机制。在过去的几年里，神经元极性调节分子已经被发现。神经元极化有两个主要的信号级联。包括我们在内的几个研究小组报道了磷脂酰肌醇3-激酶（pi3 -激酶）/Akt/糖原合成酶激酶-3β (GSK-3β)/坍缩蛋白反应介质蛋白-2通路对轴突的规范和延伸很重要。最近的研究表明，由Rho家族小GTPases和Par3/Par6/非典型蛋白激酶C复合物组成的正反馈回路在pi3激酶下游神经元极化的初始事件中起作用。在这里，我们讨论信号分子在轴突规范中的作用。
A mature neuron is typically polarized both structurally and functionally, with a single long axon and several dendrites. Neuronal polarity is essential for unidirectional signal flow from somata or dendrites to axons. The initial event in establishing a polarized neuron is the specification of a single axon. Early in neuronal development, one immature neurite becomes differentiated from other neurites to form an axon. Although studies in the past two decades have yielded a catalog of structural, molecular, and functional differences between axons and dendrites, we are only now beginning to understand the molecular mechanisms involved in the establishment of neuronal polarity. In the last few years, neuronal polarity-regulating molecules have been revealed. There are two major signaling cascades in neuronal polarization. Several groups, including ours, reported that the phosphatidylinositol 3-kinase (PI3-kinase)/Akt/glycogen synthase kinase-3β (GSK-3β)/collapsin response mediator protein-2 pathway is important for axon specification and elongation. Recent studies have revealed that the positive feedback loop composed of Rho family small GTPases and the Par3/Par6/atypical protein kinase C complex plays a role in the initial events of neuronal polarization downstream of PI3-kinase. Here, we discuss the roles of signaling molecules for axon specification.