During endocytosis the EPH-ephrin (EFN) intact complex and, possibly, associated cytoplasmic proteins, together with the surrounding plasma membrane, can be internalized into the EPH- or EFN-expressing cell. The clathrin pathway has been linked to EFNB endocytosis. C-terminal portion of EFNB1 encodes a putative endocytosis signal, a sequence that is recognized by the clathrin-associated adapter proteins required for loading molecules into clathrin-coated pits and vesicles. Treatment of cells expressing GFP-tagged EFNB1 with soluble, recombinant EPHB1/Fc fusion protein were internalized and observed in clathrin-coated vesicles. Internalized EFNB1 co-localizes with EEA1, an endosomal marker. EFNB1 internalization is inhibited by a dominant-negative dynamin mutant and potassium depletion. These results suggest that classical, clathrin-dependent endocytosis is responsible for EFNB internalization. (Parker at al. 2004).
Pat Cerretti, D,