Figure 11.

Model of transport pathways in vps52, vps53, and vps54 mutants. Resident late Golgi membrane proteins such as Kex2p and the marker protein A-ALP are transported along the CPY pathway and maintain their Golgi distribution by recycling from the PVC. Loss of retrograde transport from the PVC back to the late Golgi in vps52, vps53, or vps54 mutants leads to the slow delivery of TGN proteins, including the CPY receptor Vps10p, to the vacuole. This results in the vacuolar degradation of Golgi proteins and the secretion of CPY.