Abstract
The secretory and endocytic pathways in eukaryotic cells act as major routes for biomolecule transport out of andinto the cell. Transport from one organelle of these pathways to another is mediated by vesicular carriers, which are generated by coat protein complexes regulated by the small GTPases. The endoplasmic reticulum (ER)is the starting point for the secretory pathway, where newly synthesized membrane and soluble proteins are concentrated at specialized ER exit sites. In these distinct zones of the ER, the coat protein complex II (COPII) and the small GTPase Sar1 generate COPII vesicles through a sequence of events under the control of multiple regulatory mechanisms. In this review, the current knowledge of COPII–mediated vesicle formation from the ER, as well as highlighting non-canonical roles of COPII components are described.
