EEA1 localizes exclusively to early endosomes and has an important role in endosomal trafficking. EEA1 binds directly to the phospholipidphosphatidylinositol 3-phosphate through its C-terminal FYVE domain and forms a homodimer through a coiled coil. EEA1 acts as a tethering molecule that couples vesicle docking with SNAREs such as N-ethylmaleimide sensitive fusion protein, bringing the endosomes physically closer and ultimately resulting in the fusion and delivery of endosomal cargo.
EEA1 is a RAB5A effector protein which binds via an N-terminal zinc finger domain and is required for fusion of early and late endosomes and for sorting at the early endosome level.[5][6]
Involvement in pathogenesis[]
Due to the proteins importance in vesicular trafficking, a number of intracellular bacteria prevent EEA1 recruitment to the vacuole. Mycobacterium tuberculosis is known to inhibit the recruitment of EEA1 to the phagosomal membrane through CamKII.[7]Legionella pneumophila also prevents EEA1 recruitment through a currently unknown mechanism.[8] The related pathogen Legionella longbeachae recruits EEA1 and appears to replicate within a modified early endosome.[9]