Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-5-31
pubmed:abstractText
We have previously demonstrated that vitronectin (VN), a morphoregulatory protein in the vessel wall, is internalized and translocated to the subendothelial matrix by an integrin-independent mechanism (J. Histochem. Cytochem. 41, 1823-1832, 1993). The cell surface component which mediates the initial contact of VN with endothelial cells is defined here. The specific binding of VN to endothelial cells demonstrated the following properties: a threefold increase after phorbol ester treatment; 85% inhibition by pretreatment of cells with phosphatidylinositol-phospholipase C to release glycolipid-anchored surface proteins; a 90% inhibition by urokinase (u-PA) receptor blocking antibody. u-PA increased VN binding to cells due to an eightfold increase in the affinity of VN for the u-PA receptor. Structure-function studies showed that the amino-terminal fragment of u-PA, devoid of any proteolytic activity, mediated this effect. Active plasminogen activator inhibitor-1 (PAI-1), but not inactivated PAI-1, inhibited VN binding to cells and displaced VN that was prebound to endothelial cell monolayers. Similarly, VN binding to purified (immobilized) u-PA receptor, but not to integrin, was enhanced by u-PA and inhibited by PAI-1. Hence, the binding of soluble VN to endothelial cell surfaces is mediated by the u-PA receptor, and the relative concentrations of u-PA and PAI-1 are able to regulate the strength of this interaction. Endothelial cell adhesion to immobilized VN was found to be integrin-mediated without any involvement of the VN-uPA-receptor system. Hence, the interaction of VN with the u-PA receptor may be involved in the regulation of cellular processes necessary for endothelial cell invasion and migration at VN-rich extracellular matrix sites.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0014-4827
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
224
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
344-53
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
The urokinase receptor is a major vitronectin-binding protein on endothelial cells.
pubmed:affiliation
Haemostasis Research Unit, Kerckhoff-Klinik, Bad Nauheim, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't