Plasma membrane proteins, especally transmembrane receptors and transporters, play central roles in the maintenance of cell homeostasis and in the adaptation of the cells and organisms to changes in the environment.Besides transcriptional regulation, protein targeting, posttranslational modification, ligandbinding, protein-protein interactions, and protein degradation are all key regulatory processes that can influence the abundance and activity of these receptors and transporters.Intensive research in the last decades have shown that posttranslational modification with the small modifier protein ubiquitin is crucial for selective protein degradation.Ubiquitin-conjugated plasma membrane proteins are recognized by ubiquitin adaptors, which could work in parallel with or prior to transferring the cargo to endosomal sorting complexes required for transport (ESCRTs), a multisubunit trafficking machinery localized on endosomes (reviewed in Paez Valencia et al., 2016).ESCRT-Ⅰ and ESCRT-Ⅱ contain subunits with ubiquitin-binding domains (UBD) and are essential for ubiquitin-mediated endosomal degradation.At late endosomes, cargos are sorted into intraluminal vesicles (ILVs) of multivesicular bodies (MVBs) in an ESCRT-Ⅲ-dependent manner.Upon fusion of the limiting membrane of the MVBs with the tonoplast, ILVs are released to the lumen of the vacuole.Vacuolar proteases and lipases then break down the proteins and membranes to their building blocks so that these can be reused.Although many of the factors involved in the regulation of protein stability are conserved in eukaryotes, plants have acquired additional unique factors and mechanisms during the course of evolution.