The role of motor proteins in establishing the microtubule arrays of axons and dendrites
The role of motor proteins in establishing the microtubule arrays of axons and dendrites
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DOI：
10.1016/s0891-0618(98)00012-x
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发表时间：
1998-06-01
影响因子：
2.8
通讯作者：
Baas, PW
中科院分区：
文献类型：
--
作者：
Baas, PW
神经元产生两种不同类型的过程，称为轴突和树突，两者都依赖于高度组织化的微管阵列来生长和维持。轴突微管的正末端在细胞体的远端，方向一致，而树突状微管的方向不一致。在这两种情况下，微管都没有附着在中心体上，也没有任何可检测到的结构可以建立它们独特的极性取向模式。在这里，我描述了几条线的证据，从我的实验室，支持这些微管阵列的基础上微管运输的马达蛋白的建立模型。用于轴突和树突的微管在神经元细胞体内的中心体处成核，并迅速释放。然后释放的微管被运送到发育过程中。在神经元发育的早期，微管以其正端运输进入发育中的a？(on进入发育成树突的未成熟突起。在发育中的树突的情况下，正末端远端微管后来被一群微管连接，这些微管被运输到这些过程中，它们的负末端领先，在这个模型中隐含的是，有分子马达蛋白将微管以适当的方向运输到每种类型的过程中。有先例的分子马达蛋白运输微管在有丝分裂过程中，我们的研究结果表明，相同或相似的电机被利用后，神经母细胞成为终末有丝分裂后的轴突和树突的发展过程中。(C)1998 Elsevier Science B.V.保留所有权利。
Neurons generate two distinct types of processes called axons and dendrites, both of which rely on highly organized arrays of microtubules for their growth and maintenance. Axonal microtubules are uniformly oriented with their plus-ends distal to the cell body, while dendritic microtubules are nonuniformly oriented. In neither case are the microtubules attached to the centrosome or any detectable structure that could establish their distinct patterns of polarity orientation. Here I describe several lines of evidence from my laboratory that support a model for the establishment of these microtubule arrays based on microtubule transport by motor proteins. Microtubules destined for axons and dendrites are nucleated at the centrosome within the cell body of the neuron, and rapidly released. The released microtubules are then transported into the developing processes. Early in neuronal development, the microtubules are transported with their plus-ends-leading into the developing a?(on and into the immature processes that will develop into dendrites. In the case of the developing dendrites, the plus-end-distal microtubules are later joined by a population of microtubules that are transported into these processes with their minus-ends-leading, Implicit in this model is that there are molecular motor proteins that transport microtubules with the appropriate orientation into each type of process. There is precedent for molecular motor proteins transporting microtubules during mitosis, and our results suggest that the same or similar motors are utilized during the development of axons and dendrites after a neuroblast becomes terminally postmitotic. (C) 1998 Elsevier Science B.V. All rights reserved.