Establishment of cell-cell junctions depends on the oligomeric states of VE-cadherin.
Specifically expressed at intercellular adherens junctions of endothelial cells, VE-cadherin is a receptor that exhibits particular self-association properties. Indeed, in vitro studies demonstrated that the extracellular part of VE-cadherin elaborates Ca(++)-dependent hexameric structures. We hypothesized that this assembly could be at the basis of a new cadherin-mediated cell-cell adhesion mechanism. To verify this assumption, we first demonstrated that VE-cadherin can elaborate hexamers at the cell surface of confluent endothelial cells. Second, mutations were introduced within the extracellular part of VE-cadherin to destabilize the hexamer. Following an in vitro screening, three mutants were selected, among which, one is able to elaborate only dimers. The selected mutations were expressed as C-terminal green fluorescent protein fusions in CHO cells. Despite their capacity to elaborate nascent cell-cell contacts, the mutants seem to be rapidly degraded and/or internalized. Altogether, our results suggest that the formation of VE-cadherin hexamers protects this receptor and might allow the elaboration of mature endothelial cell-cell junctions.
Bibert
Stéphanie
S
Laboratoire d'Ingénierie des Macromolécules, Institut de Biologie Structurale Jean-Pierre Ebel, (CEA/CNRS, UJF), 41 rue Jules Horowitz, 38027 Grenoble Cedex, France. Stephanie.Bibert@unil.ch
Ayari
Hélène
H
Riveline
Daniel
D
Concord
Evelyne
E
Hermant
Bastien
B
Vernet
Thierry
T
Gulino-Debrac
Danièle
D
D022005:Adherens Junctions / Q000378:metabolism*; D000818:Animals; D015703:Antigens, CD / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016466:CHO Cells; D015820:Cadherins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D002450:Cell Communication; D006224:Cricetinae; D003412:Cricetulus; D003432:Cross-Linking Reagents / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism; D019281:Dimerization; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D047468:Immunoprecipitation; D007365:Intercellular Junctions / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009154:Mutation / Q000235:genetics; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism; D000099152:Cadherin 5
D015703:Antigens, CD; D015820:Cadherins; D002118:Calcium; D003432:Cross-Linking Reagents; D049452:Green Fluorescent Proteins; D000099152:Cadherin 5; C485184:enhanced green fluorescent protein