Wei, S.Y., Escudero, L.M., Yu, F., Chang, L.H., Chen, L.Y., Ho, Y.H., Lin, C.M., Chou, C.S., Chia, W., Modolell, J., Hsu, J.C. (2005). Echinoid is a component of adherens junctions that cooperates with DE-Cadherin to mediate cell adhesion.  Dev. Cell 8(4): 493--504.

FBrf0187414

Research paper

Echinoid is an immunoglobulin domain-containing transmembrane protein that modulates cell-cell signaling by Notch and the EGF receptors. We show that, in the Drosophila wing disc epithelium, Echinoid is a component of adherens junctions that cooperates with DE-Cadherin in cell adhesion. Echinoid and beta-catenin (a DE-Cadherin interacting protein) each possess a C-terminal PDZ domain binding motif that binds to Bazooka/PAR-3; these motifs redundantly position Bazooka to adherens junctions. Echinoid also links to actin filaments by binding to Canoe/AF-6/afadin. Moreover, interfaces between Echinoid- and Echinoid+ cells, like those between DE-Cadherin- and DE-Cadherin+ cells, are deficient in adherens junctions and form actin cables. These characteristics probably facilitate the strong sorting behavior of cells that lack either of these cell-adhesion molecules. Finally, cells lacking either Echinoid or DE-Cadherin accumulate a high density of the reciprocal protein, further suggesting that Echinoid and DE-Cadherin play similar and complementary roles in cell adhesion.