Centre Médical Universitaire, Département de Physiologie Cellulaire et Métabolisme, 1, rue Michel Servet, CH1211 Geneva 4, Switzerland.
J Cell Sci. 2010 Oct 1;123(Pt 19):3329-35. doi: 10.1242/jcs.073031. Epub 2010 Sep 7.
Efficient sorting of proteins is essential to allow transport between intracellular compartments while maintaining their specific composition. During endocytosis, membrane proteins can be concentrated in endocytic vesicles by specific interactions between their cytoplasmic domains and cytosolic coat proteins. It is, however, unclear whether they can be excluded from transport vesicles and what the determinants for this sorting could be. Here, we show that in the absence of cytosolic sorting signals, transmembrane domains control the access of surface proteins to endosomal compartments. They act in particular by determining the degree of exclusion of membrane proteins from endocytic clathrin-coated vesicles. When cytosolic endocytosis signals are present, it is the combination of cytosolic and transmembrane determinants that ultimately controls the efficiency with which a given transmembrane protein is endocytosed.
蛋白质的有效分拣对于在维持其特定组成的同时允许它们在细胞内隔室之间运输是至关重要的。在胞吞作用期间，通过细胞质域和胞质外套蛋白之间的特定相互作用，膜蛋白可以在胞吞小泡中浓缩。然而，目前尚不清楚它们是否可以被排除在运输小泡之外，以及这种分拣的决定因素是什么。在这里，我们表明，在没有胞质分拣信号的情况下，跨膜结构域控制着表面蛋白进入内体隔室的途径。它们特别通过决定膜蛋白从胞吞网格蛋白包被小泡中的排除程度来起作用。当存在胞质内吞作用信号时，最终控制特定跨膜蛋白被胞吞作用的效率的是胞质和跨膜决定因素的组合。
