PECAM-1/CD31 trans-homophilic binding at the intercellular junctions is independent of its cytoplasmic domain; evidence for heterophilic interaction with integrin alphavbeta3 in Cis.
Mol Biol Cell
; 11(9): 3109-21, 2000 Sep.
Article
em En
| MEDLINE
| ID: mdl-10982404
ABSTRACT
PECAM-1/CD31 is a cell adhesion and signaling molecule that is enriched at the endothelial cell junctions. Alternative splicing generates multiple PECAM-1 splice variants, which differ in their cytoplasmic domains. It has been suggested that the extracellular ligand-binding property, homophilic versus heterophilic, of these isoforms is controlled by their cytoplasmic tails. To determine whether the cytoplasmic domains also regulate the cell surface distribution of PECAM-1 splice variants, we examined the distribution of CD31-EGFPs (PECAM-1 isoforms tagged with the enhanced green fluorescent protein) in living Chinese hamster ovary cells and in PECAM-1-deficient endothelial cells. Our results indicate that the extracellular, rather than the cytoplasmic domain, directs PECAM-1 to the cell-cell borders. Furthermore, coculturing PECAM-1 expressing and deficient cells along with transfection of CD31-EGFP cDNAs into PECAM-1 deficient cells reveal that this PECAM-1 localization is mediated by homophilic interactions. Although the integrin alphavbeta3 has been shown to interact with PECAM-1, this trans-heterophilic interaction was not detected at the borders of endothelial cells. However, based on cocapping experiments performed on proT cells, we provide evidence that the integrin alphavbeta3 associates with PECAM-1 on the same cell surface as in a cis manner.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Endotélio Vascular
/
Receptores de Vitronectina
/
Molécula-1 de Adesão Celular Endotelial a Plaquetas
/
Junções Intercelulares
Limite:
Animals
Idioma:
En
Revista:
Mol Biol Cell
Ano de publicação:
2000
Tipo de documento:
Article