Abstract
Platelet adhesion to subendothelial von Willebrand factor involves receptor recognition by the platelet glycoprotein (GP) Ib-IX and initiates activation signals that contribute to primary hemostasis. We show here that GPIb-IX is specifically associated with an intracellular 29-kDa protein. The physicochemical characteristics and amino acid sequence of this protein indicate that it is identical to the human zeta-isoform 14-3-3 protein, previously characterized as a platelet phospholipase A2 (PLA2). As activation of PLA2 is an early event in GPIb-IX-mediated signaling, this result suggests that ligand occupancy of GPIb-IX may directly activate PLA2, leading to platelet activation.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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14-3-3 Proteins
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Amino Acid Sequence
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Chromatography, Affinity
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Electrophoresis, Polyacrylamide Gel
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Humans
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Immunoblotting
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Molecular Sequence Data
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Molecular Weight
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Nerve Tissue Proteins / blood*
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Nerve Tissue Proteins / chemistry
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Nerve Tissue Proteins / isolation & purification
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Phospholipases A / blood*
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Phospholipases A / chemistry
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Phospholipases A / isolation & purification
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Phospholipases A2
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Platelet Membrane Glycoproteins / isolation & purification
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Platelet Membrane Glycoproteins / metabolism*
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Protein Binding
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Sequence Homology, Amino Acid
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Tyrosine 3-Monooxygenase*
Substances
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14-3-3 Proteins
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Nerve Tissue Proteins
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Platelet Membrane Glycoproteins
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Tyrosine 3-Monooxygenase
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Phospholipases A
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Phospholipases A2