The intracellular domain of cadherin-11 is not required for the induction of cell aggregation, adhesion or gap-junction formation.
The cadherin family of cell adhesion molecules demonstrates calcium-dependent homophilic binding, leading to cellular recognition and adhesion. The adhesion mediated by the classical type I cadherins is strengthened through catenin-mediated coupling of the cytoplasmic domain to the cytoskeleton. This cytoskeletal interaction may not be essential for the adhesion promoted by all cadherins, several of which lack cytosolic catenin-binding sequences. Cadherin-11, a classical cadherin, possesses a cytoplasmic domain that interacts with catenins, but may also occur as a variant form expressing a truncated cytoplasmic domain. To study the role of the cytoplasmic sequence in cadherin-11 mediated adhesion we have constructed and expressed a truncated cadherin-11 protein lacking the cytoplasmic domain and unable to bind beta-catenin. Expression of the truncated cadherin-11 in MDA-MB-435S human mammary carcinoma cells reduced their motility and promoted calcium-dependent cell aggregation, frequent cell contacts, and functional gap-junctions. We conclude that the intracellular catenin-binding domain of cadherin-11, and by inference cytoskeletal interaction, is not required for the initiation and formation of cell adhesion.
Braungart
E
E
Institut für Pathologie, GSF-Forschungszentrum für Umwelt und Gesundheit, Neuherberg, Germany.
Hartman
E
E
Bechler
K
K
Höfler
H
H
Atkinson
M J
MJ
D015153:Blotting, Western; D015820:Cadherins / Q000737:chemistry* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion; D002465:Cell Movement; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D018076:DNA, Complementary / Q000378:metabolism; D017629:Gap Junctions / Q000378:metabolism / Q000648:ultrastructure; D005822:Genetic Vectors; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D015534:Trans-Activators; D014162:Transfection; D014407:Tumor Cells, Cultured; D051176:beta Catenin
C495270:CTNNB1 protein, human; D015820:Cadherins; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; D015534:Trans-Activators; D051176:beta Catenin; C086960:osteoblast cadherin; D002118:Calcium