Abstract
The Golgi complex plays a central role in the intracellular sorting of proteins. Transport through the Golgi in the anterograde direction has been explained by cisternal maturation, while transport in the retrograde direction is attributed to vesicles formed by the coat protein I (COPI) complex. A more detailed understanding of how COPI acts in Golgi transport is being achieved in recent years, due in large part to a COPI reconstitution system. Through this approach, the mechanistic complexities of COPI vesicle formation are being elucidated. This approach has also uncovered a new mode of anterograde transport through the Golgi, which involves COPI tubules connecting the Golgi cisternae. We describe in this chapter the reconstitution of COPI vesicle and tubule formation from Golgi membrane.