Figure 2.

GAP induces the formation of COPI vesicles. (A) COPI vesicles reconstituted with GAP appear similar to those formed by previous methods of reconstituting COPI vesicles. Supernatant either from the second-stage incubation for conditions involving GAP or palmitoyl-CoA, or from incubating Golgi membrane with cytosol in the presence of GTPγS was applied onto EM grids followed by immunogold labeling using antibodies directed against ɛ- or ζ-COP. Magnification, 120,000. Bar, 50 nm. (B) The level of COPI vesicles formed by reconstitution with GAP is similar to levels formed by previously established methods. A fraction (10% by volume) of the supernatant from the different incubations was applied onto EM grids for immunogold labeling using antibodies direct against ɛ- or ζ-COP, followed by quantitation for vesicles with gold particles.