Mecanismos reguladores del tráfico en la interfaz retículo endoplasmático/Golgi

Abstract

The secretory pathway transports proteins and lipids from the Endoplasmatic Reticulum (ER) to the plasma membrane and extracellular millieu, or to the membranebound compartments of the endosomal-lysosomal system. The first step of this pathway is the incorporation to vesicles bound for the Golgi of the proteins synthetized by the ER associated ribosomes, once these have been properly folded and the necessary posttranslational modifications added [1, 2]. In their journey throughout the Golgi cisternae, these proteins, collectively known as cargo, are subjected to further modifications in their N- and O-glycosilation patterns [3, 4]. Finally, cargo arrives to the Trans-Golgi Network (TGN), where is sorted and concentrated into specialized domains, and subsequently exported by membrane carriers bound for the PM or the endosomallysosomal system [5]. Transit through the different pathways of intracellular trafficking is regulated at the molecular level by several mechanisms that, on the one hand, secure that cargo reaches its destination, and on the other, maintain the identity of the different compartments that constitute the endomembrane system [6, 7]...