Negative regulator of epidermal growth factor receptor (EGFR) signaling. Acts by promoting EGFR degradation in endosomes when not monoubiquitinated (By similarity). Interacts with TRIM3. Localizes to early endosome membrane in absence of Lys-87 monoubiquitination. Localizes to cytosol when monoubiquitinated (By similarity). Enriched in brain (at protein level). 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.