Multisubunit Tethering Complexes and Their Role in Membrane Fusion

Protein trafficking within eukaryotic cells depends on vesicular carriers that fuse with organelles to deliver their lipid and protein content. Cells have developed an elaborate system to capture vesicles at organelles that involves the action of Rab GTPases and tethers. Vesicle fusion then takes place with the help of SNARE proteins. In this review we focus on the role of multisubunit tethering complexes of eukaryotic cells. In particular, we discuss the tethering complexes of the secretory pathway and the endolysosomal system and highlight recent evidence for the role of these complexes in interaction with Rabs, coat recognition and cooperation with SNAREs during the fusion cascade.