FIG. 2.

Sorting of proteins from the late Golgi to the vacuole. Vacuolar proteins are sorted in vesicles bound for the vacuole at the level of the TGN. The soluble hydrolase, CPY, binds to its membrane receptor (Vps10p) in this compartment, and the receptor-ligand complex is delivered to the PVC. In the PVC, CPY dissociates from its receptor and travels on to the vacuole while Vps10p returns to the Golgi to bind more ligand. A second pathway from the TGN to the vacuole does not pass through this compartment and is taken by the vacuolar membrane proteins ALP and Vam3p. Interestingly, the two pathways converge at, or before, the vacuolar membrane.