Abstract
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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Actins / metabolism
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Adherens Junctions / chemistry
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Adherens Junctions / metabolism*
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Animals
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Cadherins / genetics
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Cadherins / metabolism*
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Cell Adhesion / physiology*
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Cell Adhesion Molecules / genetics
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Cell Adhesion Molecules / metabolism*
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Cell Shape
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Drosophila Proteins / genetics
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Drosophila Proteins / metabolism*
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Drosophila melanogaster / anatomy & histology
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Drosophila melanogaster / genetics
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Drosophila melanogaster / growth & development
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Drosophila melanogaster / metabolism
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Embryonic Structures / cytology
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Embryonic Structures / metabolism
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Intracellular Signaling Peptides and Proteins / genetics
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Intracellular Signaling Peptides and Proteins / metabolism
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Morphogenesis
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Protein Binding
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Protein Structure, Tertiary
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Repressor Proteins / genetics
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Repressor Proteins / metabolism*
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Wings, Animal / cytology
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Wings, Animal / growth & development
Substances
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Actins
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Cadherins
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Cell Adhesion Molecules
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Drosophila Proteins
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ED protein, Drosophila
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Intracellular Signaling Peptides and Proteins
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Recombinant Fusion Proteins
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Repressor Proteins
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baz protein, Drosophila
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shg protein, Drosophila