Movement of endoplasmic reticulum in the living axon is distinct from other membranous vesicles in its rate, form, and sensitivity to microtubule inhibitors
Movement of endoplasmic reticulum in the living axon is distinct from other membranous vesicles in its rate, form, and sensitivity to microtubule inhibitors
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DOI：
10.1002/jnr.1147
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发表时间：
2001-08-01
影响因子：
4.2
通讯作者：
Mikoshiba, K
中科院分区：
文献类型：
--
作者：
Aihara, Y;Inoue, T;Mikoshiba, K
内质网（ER）是贯穿整个轴突的主要膜性成分。虽然已知其他膜结构如突触囊泡通过快速轴突运输移动，但轴突内内质网的动力学仍然未知。为了研究内质网内质钙atp酶和肌醇1,4,5-三磷酸受体这两种内质网内质钙atp酶特异性膜蛋白在轴突内的动态变化，我们用绿色荧光蛋白（GFP）标记这两种膜蛋白，并在培养的鸡背根神经节神经元中表达。gfp标记的突触素以1 μ m/s的速度以典型的快速轴突运输方式在顺行方向上以囊泡形式移动，与之相反，这两种ER蛋白并没有以离散的囊泡形式移动。光漂白技术后荧光恢复测定的它们的运动是双向的，速度慢10倍（类似于0.1妈/秒），并且对温度敏感。ER的运动速率对低剂量长春花碱和诺可唑也很敏感，但不影响synaptophysin-GFP的速率，这进一步表明它也不同于有充分记载的膜泡运动与微管的关系。j . >。Res. 65:236-246, 2001。(C) 2001 Wiley-Liss, Inc。
The endoplasmic reticulum (ER) is the major membranous component present throughout the axon. Although other membranous structures such as synaptic vesicles are known to move via fast axonal transport, the dynamics of ER in the axon still remains unknown. To study the dynamics of ER in the axon, we have directly visualized the movement of two ER-specific membrane proteins, the sarcoplasmic/endoplasmic reticulum calcium-ATPase and the inositol 1,4,5-trisphosphate receptor, both of which were tagged with green fluorescence protein (GFP) and expressed in cultured chick dorsal root ganglion neurons. In contrast to GFP-tagged synaptophysin that moved as vesicles at 1 mum/sec predominantly in the anterograde direction in the typical style of fast axonal transport, the two ER proteins did not move in a discrete vesicular form. Their movement determined by the fluorescence recovery after photobleaching technique was bi-directional, 10-fold slower (similar to0.1 mum/sec), and temperature-sensitive. The rate of movement of ER was also sensitive to low doses of vinblastine and nocodazole that did not affect the rate of synaptophysin-GFP, further suggesting that it is also distinct from the well-documented movement of membranous vesicles in its relation with microtubules. J. Neurosci. Res. 65:236-246, 2001. (C) 2001 Wiley-Liss, Inc.