Sandvig Kirsten, Grimmer Stine, Lauvrak Silje Ugland, Torgersen Maria Lyngaas, Skretting Grethe, van Deurs Bo, Iversen Tore Geir
Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, 0310 Oslo, Norway.
Histochem Cell Biol. 2002 Feb;117(2):131-41. doi: 10.1007/s00418-001-0346-2. Epub 2001 Nov 20.
The plant toxin ricin and the bacterial toxin Shiga toxin belong to a group of protein toxins that inhibit protein synthesis in cells enzymatically after entry into the cytosol. Ricin and Shiga toxin, which both have an enzymatically active moiety that inactivates ribosomes and a moiety that binds to cell surface receptors, enter the cytosol after binding to the cell surface, endocytosis by different mechanisms, and retrograde transport to the Golgi apparatus and the endoplasmic reticulum (ER). The toxins can be used to investigate the various transport steps involved, both the endocytic mechanisms as well as pathways for retrograde transport to the ER. Recent studies show that not only do several endocytic mechanisms exist in the same cell, but they are not equally sensitive to removal of cholesterol. New data have revealed that there is also more than one pathway leading from endosomes to the Golgi apparatus and retrogradely from the Golgi to the ER. Trafficking of protein toxins along these pathways will be discussed in the present article.
植物毒素蓖麻毒素和细菌毒素志贺毒素属于一类蛋白质毒素，它们进入胞质溶胶后通过酶促作用抑制细胞内的蛋白质合成。蓖麻毒素和志贺毒素都有一个使核糖体失活的酶活性部分和一个与细胞表面受体结合的部分，它们在与细胞表面结合后，通过不同机制进行内吞作用，并逆行转运至高尔基体和内质网（ER）。这些毒素可用于研究所涉及的各种转运步骤，包括内吞机制以及逆行转运至内质网的途径。最近的研究表明，同一细胞中不仅存在多种内吞机制，而且它们对胆固醇去除的敏感性也不尽相同。新数据显示，从内体到高尔基体以及从高尔基体到内质网的逆行途径也不止一条。本文将讨论蛋白质毒素沿这些途径的运输情况。
