Fig. 7. (A) Schematic model of ER-Golgi transport mediated by EGTC. COPII vesicles that bud from the ERES quickly coalesce to form clusters. These could either fuse with an existing EGTC or aggregate with each other to form a nascent EGTC (I). This process is apparently inhibited or slowed at 15°C. Within the EGTC, anterograde cargo is segregated from retrograde cargo via the action of COPI, and the EGTC `matures' by COPI-mediated retrograde transport of its components back to the ER (II). `Mature' EGTCs travel to the perinuclear region via microtubule tracks where it eventually fuses with the Golgi (III).