EH domain-dependent interactions between Eps15 and clathrin-coated vesicle protein p95.

The endocytic protein Eps15 contains three copies of the EH domain, a protein module thought to function in protein-protein interactions. Using overlay assays with an Eps15 EH domain fusion protein, we have now identified a protein of 95 kDa (p95) as a major EH domain-binding partner in a wide variety of tissues. The amino acids asparagine-proline-phenylalanine (NPF) form the core of an EH domain-binding motif and three NPF repeats are found in the endocytic protein synaptojanin-170. We have confirmed previous studies indicating that synaptojanin-170 is an EH domain-binding protein, and have used peptide blocking experiments to demonstrate that the interaction is mediated through the NPF repeats. Interestingly, the same peptide also blocks EH domain-binding to p95. Finally, we have shown that p95 is enriched on clathrin-coated vesicles, suggesting an endocytic role for the protein. These data support an important role for EH domain-NPF motif interactions in endocytosis.