ZFYVE28 is an 887 amino acid protein that contains one FYVE-type zinc finger, which mediates the interaction with PI3P (phosphatidylinositol 3-phosphate). ZFYVE28 functions as a negative regulator of EGFR (epidermal growth factor receptor) by promoting its degradation in endosomes when not monoubiquinated on Lys-87. In the absence of monoubiquination, ZFYVE28 localizes to the early endosome membrane, while it localizes to the cytosol when it is monoubiquinated. There are five isoforms of ZFYVE28 that are produced as a result of alternative splicing events.