May contribute to the sorting of ubiquitinated proteins and transfer them for further sorting/trafficking processes to the endosomal multivesicular bodies (MVBs) pathway. Binds to phospholipids, such as phosphatidylinositol PtdIns(3)P and PtdIns(3,5)P2. These phospholipids are involved in the recruitment of the ESCRT machinery to endosomal membranes (By similarity). Interacts (via GAT domain) with ubiquitin. Interacts with eps15 and chcA. Interacts with tsg101 (via UEV domain). Localized to discrete punctae throughout the cytoplasm which are distinct from endocytic vacuoles expressing endosomal protein p80. The VHS domain binds phosphatidylinositol PtdIns(3)P and PtdIns(4)P. The GAT domain binds phosphatidylinositol PtdIns(3)P, PtdIns(4)P, PI(3,5)P2 and PtdIns(4,5)P2. The Asn-Pro-Phe (NPF) motifs, which are found in proteins involved in the endocytic pathway, are known to interact with the EH domain. Cells show no change in the morphology of endocytic compartments.