title: PECAM-1: regulator of endothelial junctional integrity.
abstract: PECAM-1 (also known as CD31) is a cellular adhesion and signaling receptor comprising six extracellular immunoglobulin (Ig)-like homology domains, a short transmembrane domain and a 118 amino acid cytoplasmic domain that becomes serine and tyrosine phosphorylated upon cellular activation. PECAM-1 expression is restricted to blood and vascular cells. In circulating platelets and leukocytes, PECAM-1 functions largely as an inhibitory receptor that, via regulated sequential phosphorylation of its cytoplasmic domain, limits cellular activation responses. PECAM-1 is also highly expressed at endothelial cell intercellular junctions, where it functions as a mechanosensor, as a regulator of leukocyte trafficking and in the maintenance of endothelial cell junctional integrity. In this review, we will describe (1) the functional domains of PECAM-1 and how they contribute to its barrier-enhancing properties, (2) how the physical properties of PECAM-1 influence its subcellular localization and its ability to influence endothelial cell barrier function, (3) various stimuli that initiate PECAM-1 signaling and/or function at the endothelial junction and (4) cross-talk of PECAM-1 with other junctional molecules, which can influence endothelial cell function.
authors.affiliation: Blood Research Institute, BloodCenter of Wisconsin, P.O. Box 2178, 638N. 18th Street, Milwaukee, WI, 53201, USA.
authors.forename: Jamie R
authors.initials: JR
authors.lastname: Privratsky
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Newman
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism*; D006801:Humans; D007365:Intercellular Junctions / Q000378:metabolism / Q000502:physiology*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism*
chemical_list: D019408:Platelet Endothelial Cell Adhesion Molecule-1