The platelet protein kinase C substrate pleckstrin binds directly to SDPR protein
Autor: | Akeel Baig, Marlene Wolf, Richard J. Haslam, Xiankun Bao |
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Rok vydání: | 2009 |
Předmět: |
Blood Platelets
Immunoblotting Plasma protein binding environment and public health Mass Spectrometry Mice Animals Humans Immunoprecipitation Phosphorylation Protein kinase B Protein Kinase C Protein kinase C Mice Knockout Chemistry Blood Proteins Hematology General Medicine Phosphate-Binding Proteins Phosphoproteins IRS1 Cell biology Pleckstrin homology domain enzymes and coenzymes (carbohydrates) lipids (amino acids peptides and proteins) sense organs biological phenomena cell phenomena and immunity Signal transduction Carrier Proteins SDPR Protein Binding Signal Transduction |
Zdroj: | Platelets. 20:446-457 |
ISSN: | 1369-1635 0953-7104 |
DOI: | 10.3109/09537100903137314 |
Popis: | Pleckstrin is a modular platelet protein consisting of N- and C-terminal pleckstrin homology (PH) domains, a central dishevelled egl10 and pleckstrin (DEP) domain and a phosphorylation region. Following agonist-induced platelet stimulation, dimeric pleckstrin translocates to the plasma membrane, is phosphorylated and then monomerizes. A recent study found that pleckstrin null platelets from a knockout mouse have a defect in granule secretion, actin polymerization and aggregation. However, the mechanism of pleckstrin signaling for this function is unknown. Our recent studies have led to the identification of a novel pleckstrin-binding protein, serum deprivation response protein (SDPR), by co-immunoprecipitation, GST-pulldowns and nanospray quadruple time of flight mass spectrometry. We show that this interaction occurs directly through N-terminal sequences of pleckstrin. Both pleckstrin and SDPR are phosphorylated by protein kinase C (PKC), but the interaction between pleckstrin and SDPR was shown to be independent of PKC inhibition or activation. These results suggest that SDPR may facilitate the translocation of nonphosphorylated pleckstrin to the plasma membrane in conjunction with phosphoinositides that bind to the C-terminal PH domain. After binding of pleckstrin to the plasma membrane, its phosphorylation by PKC exerts downstream effects on platelet aggregation/secretion. |
Databáze: | OpenAIRE |
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