Abstract
Cell to cell interaction in bone marrow is crucial for differentiation of hematopoietic cells. We have shown that EphB4 receptor is expressed in erythroid progenitor and its activation accelerates erythroid differentiation. To elucidate the role of EphB4 activation in erythropoiesis, we analyzed effects of EphB4 on cell adhesive pathways. Cell adhesion with the extension of filopodial pseudopod was observed by EphB4 activation. EphB4 activation also enhanced an effect of fibronectin-mediated adhesive pathway along with formation of the c-Cbl/CrkL complex. The tyrosine kinase activity of EphB4 was dispensable for those phenomena. These results suggest that activation of EphB4 participates in adhesive but not repulsive signals independently of its tyrosine kinase activity in hematopoietic cells.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptor Proteins, Signal Transducing*
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Animals
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Bone Marrow Cells / metabolism
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Cell Adhesion / physiology*
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Cell Differentiation / physiology
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Cell Line
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Cell Surface Extensions / metabolism
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Ephrin-B2 / metabolism*
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Erythropoiesis / physiology
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Fibronectins / metabolism
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Hematopoietic Stem Cells / physiology*
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Humans
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K562 Cells
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Mice
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Nuclear Proteins / metabolism
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Phosphorylation
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Proto-Oncogene Proteins / metabolism
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Proto-Oncogene Proteins c-cbl
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Receptor, EphB4 / genetics
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Receptor, EphB4 / metabolism*
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Tyrosine / metabolism
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Ubiquitin-Protein Ligases / metabolism
Substances
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Adaptor Proteins, Signal Transducing
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CRKL protein
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Ephrin-B2
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Fibronectins
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Nuclear Proteins
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Proto-Oncogene Proteins
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Tyrosine
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Proto-Oncogene Proteins c-cbl
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Ubiquitin-Protein Ligases
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Receptor, EphB4
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CBL protein, human
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Cbl protein, mouse