| Background | Early endosomal antigen 1 (EEA1) is a 162 kDa membrane bound protein component specific to the early endosome and is essential for fusion between early endocytic vesicles. Early endosomes are cytoplasmic compartments which fuse with endocytic vesicles for redistribution of extracellular compounds to alternate destinations. Zinc-finger-like domains, reminiscent of those found in nucleic acid binding proteins, are located in the amino and carboxyl-terminal domains of EEA1. The carboxyl-terminal zinc-finger-like-domain is conserved in several other non-nuclear proteins, some of which are also involved in intracellular protein trafficking. In addition, this domain is an authentic zinc-binding domain and is critical to the intracellular localization of EEA1. Membrane association of EEA1 has been shown dependent on phosphatidyl 3-kinase activity, inhibitors of which cause EEA1 to dissociate from early endosomes. |