Component of the DSC E3 ubiquitin ligase complexes that tag proteins present in Golgi, endosome and vacuole membranes and function in protein homeostasis under non-stress conditions and support a role in protein quality control (PubMed:25078903, PubMed:29355480). Involved in CDC48-dependent protein degradation through the ubiquitin/proteasome pathway. Involved in delivery of substrates to the 26S proteasome. Also required for membrane fusion (By similarity). Component of the DSC E3 ligase complexes composed of at least TUL1, DSC2, DSC3, UBX3, CDC48 as well as VLD1 for the vacuole-localized complex or GLD1 for the Golgi/endosome-localized complex (PubMed:29355480). Interacts with CDC48 (PubMed:15258615). Present with 233 molecules/cell in log phase SD medium.