Model illustrating ubiquitin-mediated vacuolar transport of membrane proteins. Ubiquitin acts as an internalization signal at the PM for the endocytic route but also redirects Golgi-localized membrane proteins into the vacuolar degradation pathway. Both pathways merge at the TGN/EE. The ESCRT-I subunit VPS28 localizes to the Golgi and the TGN/EE but not to the MVB/LE . This could suggest that ESCRT-mediated sorting is initiated at these compartments.