Membrane protein transport between the endoplasmic reticulum and the golgi in tobacco leaves is energy dependent but cytoskeleton independent: Evidence from selective photobleaching
Membrane protein transport between the endoplasmic reticulum and the golgi in tobacco leaves is energy dependent but cytoskeleton independent: Evidence from selective photobleaching
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DOI：
10.1105/tpc.001586
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发表时间：
2002-06-01
期刊：
影响因子：
11.6
通讯作者：
Hawes, C
中科院分区：
文献类型：
--
作者：
Brandizzi, F;Snapp, EL;Hawes, C
控制蛋白质在植物内质网和高尔基体之间运输的机制尚不清楚。在这里，我们使用电子显微镜检查烟叶中高尔基体膜和内质网膜之间的结构关系，并证明高尔基体膜含有与内质网密切相关和/或直接接触的元素。我们使用绿色荧光蛋白标记的高尔基体标记蛋白进一步可视化内质网和高尔基体之间的蛋白质运输。利用光漂白技术，我们发现高尔基膜标记以能量依赖和n -乙基马来酰亚胺敏感的方式组成高尔基循环。我们发现膜蛋白向高尔基体的转运独立于细胞骨架发生，不需要高尔基体沿着内质网表面运动。Brefeldin A治疗阻断高尔基蛋白在重新分配到内质网之前的正向运输。我们的研究结果表明，在植物细胞中，高尔基体是一个动态的膜系统，其成分通过由brefeldin a -和n -乙基马来酰亚胺敏感机制调节的膜运输途径持续运输。
The mechanisms that control protein transport between the endoplasmic reticulum (ER) and the Golgi apparatus are poorly characterized in plants. Here, we examine in tobacco leaves the structural relationship between Golgi and ER membranes using electron microscopy and demonstrate that Golgi membranes contain elements that are in close association and/or in direct contact with the ER. We further visualized protein trafficking between the ER and the Golgi using Golgi marker proteins tagged with green fluorescent protein. Using photobleaching techniques, we showed that Golgi membrane markers constitutively cycle to and from the Golgi in an energy-dependent and N-ethylmaleimide-sensitive manner. We found that membrane protein transport toward the Golgi occurs independently of the cytoskeleton and does not require the Golgi to be motile along the surface of the ER. Brefeldin A treatment blocked forward trafficking of Golgi proteins before their redistribution into the ER. Our results indicate that in plant cells, the Golgi apparatus is a dynamic membrane system whose components continuously traffic via membrane trafficking pathways regulated by brefeldin A- and N-ethylmaleimide-sensitive machinery.