Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1989-12-8
pubmed:abstractText
Activation of protein kinase C (PKC), as revealed by phosphorylation of a 47 kd protein (p47), occurs in platelets stimulated by some agonists (eg, thrombin or phorbol esters). It is not known if activation of PKC occurs with pairs of agonists, such as epinephrine and A23187, that do not individually phosphorylate p47, nor is it known what role the concentration of cytoplasmic Ca++ ([Ca++]i) plays in these events. We stimulated aequorin-loaded platelets with subaggregating concentrations of epinephrine and A23187, neither of which by itself phosphorylated p47. The combination of agonists resulted in p47 phosphorylation, an increase in platelet-bound fibrinogen, and aggregation, but only if the concentration of each agonist was sufficient to increase [Ca++]i if it was added separately. Subaggregating concentrations of A23187 alone released platelet fibrinogen and increased platelet membrane binding of [3H]-phorbol dibutyrate, but these were not enhanced by epinephrine. Epinephrine and A23187 did not increase production of diacylglycerol. Thus, epinephrine and A23187 together activate PKC by a mechanism that does not require phospholipase C or enhanced binding of PKC to the plasma membrane; PKC activation in turn is correlated with enhanced platelet fibrinogen binding and aggregation. These events require an initial elevation of [Ca++]i above a threshold.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
74
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2001-6
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Activation of protein kinase C in platelets by epinephrine and A23187: correlation with fibrinogen binding.
pubmed:affiliation
Charles A. Dana Research Institute, Harvard Medical School, Boston, MA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.