EXPERIMENTAL FIGURE 14-7 Vesicle buds can be visualized during in vitro budding reactions. When purified COPII coat components are incubated with isolated ER vesicles or artificial phospholipid vesicles (liposomes), polymerization of the coat proteins on the vesicle surface induces emergence of highly curved buds. In this electron micrograph of an in vitro budding reaction, note the distinct membrane coat, visible as a dark protein layer, present on the vesicle buds.

[Republished with permission of Elsevier, from Matsuoka, K. et al., “COPII-coated vesicle formation reconstituted with purified coat proteins and chemically defined liposomes,” 1998, Cell 93(2):263–275; permission conveyed through the Copyright Clearance Center, Inc.]