Presley J F, Cole N B, Schroer T A, Hirschberg K, Zaal K J, Lippincott-Schwartz J
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, NIH, Bethesda, Maryland 20892, USA.
Nature. 1997 Sep 4;389(6646):81-5. doi: 10.1038/38001.
Newly synthesized proteins that leave the endoplasmic reticulum (ER) are funnelled through the Golgi complex before being sorted for transport to their different final destinations. Traditional approaches have elucidated the biochemical requirements for such transport and have established a role for transport intermediates. New techniques for tagging proteins fluorescently have made it possible to follow the complete life history of single transport intermediates in living cells, including their formation, path and velocity en route to the Golgi complex. We have now visualized ER-to-Golgi transport using the viral glycoprotein ts045 VSVG tagged with green fluorescent protein (VSVG-GFP). Upon export from the ER, VSVG-GFP became concentrated in many differently shaped, rapidly forming pre-Golgi structures, which translocated inwards towards the Golgi complex along microtubules by using the microtubule minus-end-directed motor complex of dynein/dynactin. No loss of fluorescent material from pre-Golgi structures occurred during their translocation to the Golgi complex and they frequently stretched into tubular shapes. Together, our results indicate that these pre-Golgi carrier structures moving unidirectionally along microtubule tracks are responsible for transporting VSVG-GFP through the cytoplasm to the Golgi complex. This contrasts with the traditional focus on small vesicles as the primary vehicles for ER-to-Golgi transport.
离开内质网（ER）的新合成蛋白质在被分类运输到不同的最终目的地之前，会通过高尔基体复合体。传统方法已经阐明了这种运输的生化要求，并确定了运输中间体的作用。荧光标记蛋白质的新技术使得追踪活细胞中单个运输中间体的完整生命历程成为可能，包括它们的形成、路径和前往高尔基体复合体途中的速度。我们现在使用标记有绿色荧光蛋白（VSVG-GFP）的病毒糖蛋白ts045 VSVG来观察内质网到高尔基体的运输。从内质网输出后，VSVG-GFP集中在许多形状各异、快速形成的高尔基体前结构中，这些结构利用动力蛋白/动力蛋白激活蛋白的微管负端定向运动复合体，沿着微管向内朝向高尔基体复合体移动。在高尔基体前结构向高尔基体复合体转运的过程中，没有荧光物质从这些结构中丢失，并且它们经常伸展成管状。总之，我们的结果表明，这些沿着微管轨道单向移动的高尔基体前载体结构负责将VSVG-GFP通过细胞质运输到高尔基体复合体。这与传统上把小囊泡作为内质网到高尔基体运输的主要载体的观点形成了对比。
