Visualization of translated tau protein in the axons of neuronal P19 cells and characterization of tau RNP granules
Visualization of translated tau protein in the axons of neuronal P19 cells and characterization of tau RNP granules
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DOI：
10.1242/jcs.00058
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发表时间：
2002-10-01
影响因子：
4
通讯作者：
Ginzburg, I
中科院分区：
文献类型：
--
作者：
Aronov, S;Aranda, G;Ginzburg, I
tau mRNA 定位到轴突需要轴突定位顺式信号 (ALS)（位于 3' 非翻译区域内）和反式作用结合蛋白（是神经元细胞中观察到的颗粒结构的一部分）。在这项研究中，我们使用生化和形态学方法，证明颗粒含有 tau mRNA、稳定 mRNA 的 HuD RNA 结合蛋白，以及参与顺行运输的驱动蛋白微管相关运动蛋白家族的成员 KIF3A。沿着轴突检测到颗粒并积聚在生长锥中。抑制 KIF3A 表达会导致神经突收缩并抑制 tau mRNA 轴突靶向。总而言之，这些结果表明 HuD 和 KIF3A 蛋白存在于 tau mRNA 轴突颗粒中，并表明驱动蛋白运动家族在 RNA 颗粒的微管依赖性易位中具有额外的功能。局部 tau-GFP 表达被蛋白质合成抑制剂阻断，抑制解除后，在轴突和生长锥中直接观察到新生 tau-GFP“热点”。这些观察结果与轴突中由运输的 tau mRNA 产生的局部蛋白质合成一致。
Localization of tau mRNA to the axon requires the axonal localization cis signal (ALS), which is located within the 3' untranslated region, and trans-acting binding proteins, which are part of the observed granular structures in neuronal cells. In this study, using both biochemical and morphological methods, we show that the granules contain tau mRNA, HuD RNA-binding protein, which stabilizes mRNA, and KIF3A, a member of the kinesin microtubule-associated motor protein family involved in anterograde transport. The granules are detected along the axon and accumulate in the growth cone. Inhibition of KIF3A expression caused neurite retraction and inhibited tau mRNA axonal targeting. Taken together, these results suggest that HuD and KIF3A proteins are present in the tau mRNA axonal granules and suggest an additional function for the kinesin motor family in the microtubule-dependent translocation of RNA granules. Localized tau-GFP expression was blocked by a protein synthesis inhibitor, and upon release from inhibition, nascent tau-GFP 'hot spots' were directly observed in the axon and growth cones. These observations are consistent with local protein synthesis in the axon resulting from the transported tau mRNA.