[Creation of artificial receptors activated by coiled-coil peptides and cellular regulation]

Exploiting the ability of coiled-coil peptides to induce dimer formation, we designed an artificial epidermal growth factor receptor (EGFR) in which dimerization is essential for increasing the tyrosine kinase activity of its intracellular domain. Using leucine-zipper coiled-coil peptides, the surface-exposed E3 ((EIAALEK)3) tag sequence was fused with EGFR (E3-EGFR) lacking domains I-III and a part of IV, which participate in dimerization of EGFR after binding to natural ligand (that is, epidermal growth factor). To dimerize E3-EGFR we synthesized conjugates of two K4 ((KIAALKE)4) peptides, called K4-conjugates, with linker lengths approximately 10 angstrom that mimic the distance of EGFR dimerization. Receptor phosphorylation of E3-EGFR was found to increase within 5 min in CHO cells expressing E3-EGFR after treatment with K4 conjugates. Increased lamellipodia formation and migration of the cells was also observed when treated with the artificial ligands. This receptor model can be applied to a wide variety of membrane-associated proteins to control cellular processes and to elucidate the functional mechanisms of these proteins using chemical biology.