REPS1 is a RalBP1-associated EH-homology domain containing protein. The sequence of REPS1 has an EH domain, followed by two proline-rich segments, and a C-terminal coiled-coil domain for binding to RalBP1. The EH domain of REPS1 interacts with the NPF motif of Rab11-FIP2, mediates their colocalization to endosome vesicles, and influences EGFR endocytosis. The two proline-rich regions of REPS1 are important for binding to the SH3 domain of GRK/GRB2 and further regulate EGFR downstream signaling. The proline-rich regions of REPS1 have also been shown to interact with the SH3 domain of intersectin1 (ITSN1) and contribute to ITSN1/SGIP1/REPS1 complex formation on clathrin-coated pits. Three alternatively spliced isoforms of REPS1 have been identified. |