Negative regulator of epidermal growth factor receptor (EGFR) signaling. Acts by promoting EGFR degradation in endosomes when not monoubiquitinated (By similarity). Localizes to early endosome membrane in absence of Lys-87 monoubiquitination. Localizes to cytosol when monoubiquitinated (By similarity). The FYVE-type zinc finger mediates the interaction with phosphatidylinositol 3-phosphate (PI3P) and localization to early endosome membranes when not monoubiquitinated at Lys-87. Monoubiquitination at Lys-87 prevents binding to phosphatidylinositol 3-phosphate (PI3P) and localization to early endosome membranes. Belongs to the lst-2 family.