Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
2002-4-8
pubmed:abstractText
Phosphoinositide 3-kinase (PI3K) is a critical component of the signaling pathways that control the activation of platelets. Here we have examined the regulation of protein kinase B (PKB), a downstream effector of PI3K, by the platelet collagen receptor glycoprotein (GP) VI and thrombin receptors. Stimulation of platelets with collagen or convulxin (a selective GPVI agonist) resulted in PI3K-dependent, and aggregation independent, Ser(473) and Thr(308) phosphorylation of PKBalpha, which results in PKB activation. This was accompanied by translocation of PKB to cell membranes. The phosphoinositide-dependent kinase PDK1 is known to phosphorylate PKBalpha on Thr(308), although the identity of the kinase responsible for Ser(473) phosphorylation is less clear. One candidate that has been implicated as being responsible for Ser(473) phosphorylation, either directly or indirectly, is the integrin-linked kinase (ILK). In this study we have examined the interactions of PKB, PDK1, and ILK in resting and stimulated platelets. We demonstrate that in platelets PKB is physically associated with PDK1 and ILK. Furthermore, the association of PDK1 and ILK increases upon platelet stimulation. It would therefore appear that formation of a tertiary complex between PDK1, ILK, and PKB may be necessary for phosphorylation of PKB. These observations indicate that PKB participates in cell signaling downstream of the platelet collagen receptor GPVI. The role of PKB in collagen- and thrombin-stimulated platelets remains to be determined.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12874-8
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Protein kinase B is regulated in platelets by the collagen receptor glycoprotein VI.
pubmed:affiliation
School of Animal & Microbial Sciences, University of Reading, Whiteknights, Reading RG6 6AJ, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't