Acts as a gatekeeper for degradative protein sorting to the vacuole. Plays a role in recognition of ubiquitinated PIN2 auxin carrier at the plasma membrane and further to its endocytic sorting. Binds ubiquitin in vitro (PubMed:24316203). Might contribute to the loading of the ESCRT machinery (Probable). Ubiquitously expressed. Belongs to the TOM1 family.