Localization of the Lys, Asp, Glu, Leu tetrapeptide receptor to the Golgi complex and the intermediate compartment in mammalian cells

There is now a general consensus that the IC is indeed distal to the rough ER but distinct from the Man I compartment, and that the anterograde traffic into the Golgi complex is mediated by vesicles (Balch, 1990; Hauri and Schweizer, 1992; Schekman, 1992) . Nevertheless, considerable controversy remains about the nature of the connections between the rough ER and the IC. One model proposes that the IC is physically distinct from the rough ER, with a different lumenal environment, and that traffic between the two organelles would be mediated by vesicular traffic (i.e., two vesicular steps from rough ER to Golgi) (Warren, 1987; Pelham, 1989; Lippincott-Schwartz et al., 1990; Balch, 1990) .