Fig. 1.

Localization of COPII in mammalian cells. a Sec24C (COPII, green) and giantin (a marker of the cis-/medial-Golgi, red) in HeLa cells. Note the close proximity of the two structures in the juxtanuclear region results in apparent colocalization and yellow colouring in the merge. Bar 10 μm. b Sec24C (red) and calnexin (green) show the presence of ERES on ER membranes. Bar 10 μm. c Immunofluorescence labelling of methanol fixed HeLa cell shows the close apposition but distinct localization of Sec24C (COPII, green) and ERGIC-53 (red, a marker of the ER-Golgi intermediate compartment). Arrowheads highlight the clear separation of the two structures. Bar 5 μm. Individual green and red channels are shown alongside the merge for clarity