Components responsible for transport between successive Golgi cisternae are highly conserved in evolution.

Transport of a glycoprotein between compartments of the Golgi has been reconstituted in an in vitro system (Balch, W. E., Dunphy, W. G., Braell, W. A., and Rothman, J. E. (1984) Cell 39, 405-416). Cytosolic components and ATP are absolutely required for transport. Here, we have tested the acceptor activity of Golgi fractions and of cytosolic fractions prepared from a variety of organisms. All mammalian Golgi fractions can act as "acceptor" in the in vitro assay. Similarly, the cytosol fractions obtained from plants as well as animals and a lower eukaryote substitute for the homologous CHO cytosol normally used. Moreover, a cytosol subfraction prepared from wheat germ complements a different cytosolic fraction obtained from bovine brain. Apparently, the essential components involved in the post-translational protein transport are remarkably conserved between plants, animals, and lower eukaryotes.