EEA1, an early endosome-associated protein. EEA1 is a conserved α- helical peripheral membrane protein flanked by cysteine 'fingers' and contains a calmodulin-binding IQ motif

Abstract

Early endosomes are cellular compartments receiving endocytosed material and sorting them for vesicular transport to late endosomes and lysosomes or for recycling to the plasma membrane. We have cloned a human cDNA encoding an evolutionarily conserved 180-kDa protein on early endosomes named EEA1 (Early Endosome Antigen1). EEA1 is associated with early endosomes since it co- localizes by immunofluorescence with the transferrin receptor and with Rab5 but not with Rab7. Immunoelectron microscopy shows that it is associated with tubulovesicular early endosomes containing internalized bovine serum albumin- gold. EEA1 is a hydrophilic peripheral membrane protein present in cytosol and membrane fr..