Starkuviene Vytaute, Pepperkok Rainer
Cell Biology and Cell Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
Traffic. 2007 Aug;8(8):1035-51. doi: 10.1111/j.1600-0854.2007.00582.x. Epub 2007 Jun 5.
Emerging experimental evidence favours the existence of cargo sorting occurring upon the endoplasmic reticulum (ER) exit. Recent studies revealed that, in contrast to the conventional secretory marker ts-O45-G, procollagen (PC I) exits the ER at sites not coated with coat protein II and is transported to the Golgi complex in carriers devoid of coat protein I. Here, we investigated whether PC I trafficking requires a different molecular machinery in comparison with the ts-O45-G. By combining colocalization of the cargoes with endogenous markers, downregulation of transport machinery by RNA interference and knock-ins by complementary DNA over-expression, we provide strong evidence that PC I and ts-O45-G have common but also different molecular requirements during pre- and post-Golgi trafficking events.
新出现的实验证据支持在内质网（ER）出口处存在货物分选现象。最近的研究表明，与传统的分泌标记物ts-O45-G不同，原胶原（PC I）在内质网未被II型包被蛋白包被的位点处离开内质网，并通过缺乏I型包被蛋白的载体转运至高尔基体复合体。在此，我们研究了与ts-O45-G相比，PC I的运输是否需要不同的分子机制。通过将货物与内源性标记物共定位、利用RNA干扰下调运输机制以及通过互补DNA过表达进行敲入，我们提供了强有力的证据，表明PC I和ts-O45-G在高尔基体前和高尔基体后运输事件中具有共同但也不同的分子需求。
