The binding of AP-1 clathrin adaptor particles to Golgi membranes requires ADP-ribosylation factor, a small GTP-binding protein.

The small GTP-binding protein, ADP-ribosylation factor (ARF), has previously been shown to mediate the binding to Golgi membranes of the coatomer of non-cathrin-coated (COP-coated) vesicles. We now report that ARF is also required for the binding of the AP-1 adaptor protein of clathrin-coated vesicles to Golgi membranes. The binding of coat proteins from both clathrin- and COP-coated vesicles requires an additional Golgi membrane-associated factor. These results suggest that a mechanistic similarity underlies diverse types of vesicle coats.