Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-8-31
pubmed:abstractText
During platelet adhesion, the complex cytoskeletal structure is rearranged resulting in the formation of F-actin-based filopodia and lamellipodia. Stimulatory platelet signalling pathways include binding of integrin alpha(IIb)beta(3) to fibrinogen followed by activation of protein tyrosine kinases (PTK) and phosphorylation of downstream signalling proteins. In this study, we demonstrate that the scaffolding and F-actin binding protein LASP-1 undergoes tyrosine phosphorylation in thrombin-stimulated human platelets. By means of specific inhibitors we identified Src-kinase as the primary enzyme phosphorylating LASP-1 in intact cells. These data were confirmed in platelet model cells (A5-CHO cells), constitutively expressing integrin alpha(IIb)beta(3). Fibrinogen-mediated cell stimulation resulted in a similar tyrosine phosphorylation of transiently transfected LASP-1. Site directed mutagenesis identified tyrosine 171 as the Src-kinase phosphorylation site. Immunofluorescence microscopic analysis of these cells revealed a relocation of LASP-1 to focal contacts and the leading edge of the membrane upon fibrinogen activation and tyrosine 171 phosphorylation. This translocation was also seen in adherent platelets. Concomitant with adhesion, LASP-1 translocated from the cytosol along the arms of the pseudopodia into the leading lamellae of the spreading platelets, indicating a crucial role of the protein in platelet cytoskeleton rearrangement.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0340-6245
pubmed:author
pubmed:issnType
Print
pubmed:volume
102
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
520-8
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Integrin-dependent translocation of LASP-1 to the cytoskeleton of activated platelets correlates with LASP-1 phosphorylation at tyrosine 171 by Src-kinase.
pubmed:affiliation
Institute of Clinical Biochemistry and Pathobiochemistry, University of Wuerzburg, D-97080 Wuerzburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't