EEA1 is essential for the tethering and fusion of early endosomes. It interacts with Rab5, a small GTPase, to facilitate the docking of transport vesicles coming from the plasma membrane. This interaction is critical for the maturation of early endosomes and the sorting of endocytosed materials. Without EEA1, the efficiency of endocytosis and the subsequent intracellular trafficking would be significantly impaired.
