Luminal material in microtubules of frog olfactory axons: structure and distribution.
Luminal material in microtubules of frog olfactory axons: structure and distribution.
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DOI：
10.1083/jcb.99.2.520
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发表时间：
1984-08
期刊：
影响因子：
--
通讯作者：
Burton PR
中科院分区：
文献类型：
--
作者：
Burton PR
对牛蛙嗅轴突微管腔内物质的亚结构和分布进行了研究。通过使用多种固定方法，有或没有四氧化锇，luminal成分被证明不是固定的工件。该材料由直径4-5纳米的球状元素组成，松散地排列在管腔内，呈不连续的柱状。嗅觉神经近端和远端轴突显示管腔物质的微管计数，发现远端显示管腔成分的微管多16-18%。这增加了物质可能在微管腔内易位的可能性，并倾向于在向远端轴突末端移动时积累。与嗅觉轴突相比，由青蛙脑微管蛋白在体外组装的微管没有显示管腔物质。嗅觉轴突微管经低温和钙处理原位解聚后再诱导重组后，新生形成的微管多出现空腔。这些证据表明，管腔物质不是微管的组成部分。讨论了物质可能在微管腔内移位的假设。此外，在神经元微管的情况下，它们可能作为自己的壁亚基的管道。
The substructure and distribution of luminal material in microtubules of olfactory axons were studied in the bullfrog, Rana catesbeiana. By using numerous fixation methods, with and without osmium tetroxide, the luminal component was shown not to be an artifact of fixation. The material consists of globular elements 4-5 nm in diameter loosely arranged within the lumen in a discontinuous column. Counts of microtubules showing luminal material were obtained for axons in the proximal and distal ends of the olfactory nerve, and it was found that 16-18% more of the microtubules in the distal regions showed the luminal component. This raises the possibility that the material might be translocated within the microtubule lumen and tends to accumulate as it moves distally toward the axon terminal. In contrast to those of the olfactory axons, microtubules assembled in vitro from frog brain tubulin did not show luminal material. When microtubules in olfactory axons were depolymerized in situ by cold and calcium treatment and then induced to reassemble, most of those that were formed de novo showed empty lumina. Such evidence suggests that the luminal material is not an integral component of the microtubule. The hypothesis is discussed that material may be translocated within the lumina of microtubules. Furthermore, in the case of neuronal microtubules, the possibility is raised that they may serve as conduits for their own wall subunits.