Botanical Institute, Lehrstuhl III, Biozentrum Köln, Zülpicher Strasse 47b, Cologne, Germany.
Plant Mol Biol. 2011 May;76(1-2):85-96. doi: 10.1007/s11103-011-9770-4. Epub 2011 Mar 26.
In yeast, endosomal sorting of monoubiquitylated transmembrane proteins is performed by a subset of the 19 "class E vacuolar protein sorting" proteins. The core machinery consists of 11 proteins that are organised in three complexes termed ESCRT I-III (endosomal sorting complex required for transport I-III) and is conserved in eukaryotic cells. While the pathway is well understood in yeast and animals, the plant ESCRT system is largely unexplored. At least one sequence homolog for each ESCRT component can be found in the Arabidopsis genome. Generally, sequence conservation between yeast/animals and the Arabidopsis proteins is low. To understand details about participating proteins and complex organization we have performed a systematic pairwise yeast two hybrid analysis of all Arabidopsis proteins showing homology to the ESCRT core machinery. Positive interactions were validated using bimolecular fluorescence complementation. In our experiments, most putative ESCRT components exhibited interactions with other ESCRT components that could be shown to occur on endosomes suggesting that despite their low homology to their yeast and animal counterparts they represent functional components of the plant ESCRT pathway.
在酵母中，单泛素化跨膜蛋白的内体分选是由一组 19 种“E 类液泡蛋白分选”蛋白中的一部分完成的。核心机制由组织在三个复合物中的 11 种蛋白组成，称为 ESCRT I-III（内体分选复合物需要运输 I-III），并在真核细胞中保守。虽然该途径在酵母和动物中得到了很好的理解，但植物 ESCRT 系统在很大程度上尚未被探索。拟南芥基因组中至少可以找到每个 ESCRT 成分的一个序列同源物。通常，酵母/动物和拟南芥蛋白之间的序列保守性较低。为了了解参与蛋白和复合物组织的详细信息，我们对所有显示与 ESCRT 核心机制同源的拟南芥蛋白进行了系统的两两酵母双杂交分析。使用双分子荧光互补验证了阳性相互作用。在我们的实验中，大多数假定的 ESCRT 成分与其他 ESCRT 成分相互作用，这些相互作用可以在内涵体上显示出来，这表明尽管它们与酵母和动物对应物的同源性较低，但它们代表了植物 ESCRT 途径的功能成分。
