Notch signalling via RBP-J promotes myeloid differentiation.
The expression of Notch receptors on hematopoietic cells and of cognate ligands on bone marrow stromal cells suggests a possible role for Notch signalling in the regulation of hematopoiesis. In order to assess the involvement of Notch1 signalling in myelopoiesis, 32D myeloid progenitor cell lines were engineered to permit the conditional induction of the constitutively active intracellular domain of murine Notch1 (mN1(IC)) by the 4-hydroxytamoxifen-inducible system. The induction of mN1(IC) resulted in accelerated and increased granulocytic differentiation. These effects were observed under growth conditions that support differentiation and, to a lesser degree, under conditions that normally promote self-renewal. Transient transfection of mN1(IC) deletion mutants showed that the differentiation promoting activity correlated with RBP-J transactivation. Furthermore, expression of a transcriptionally active derivative of RBP-J (RBP-J-VP16) increased myeloid differentiation. To test further the role of Notch signalling in a physiological context, 32D cells expressing mNotch1 were cultured on fibroblast layers that either expressed or did not express the Notch ligand Jagged1. Similar to the induction of mN1(IC), Jagged1 accelerated granulocytic differentiation of 32D cells. Taken together, our data suggest that activation of mNotch1 promotes myeloid differentiation via RBP-J transactivation.
Schroeder
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GSF, National Research Centre for Environment and Health, Institute for Clinical Molecular Biology, Marchioninistrabetae 25, D-81377 Munich, Germany.
Just
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D000818:Animals; D002135:Calcium-Binding Proteins; D002454:Cell Differentiation; D002460:Cell Line; D002999:Clone Cells; D004268:DNA-Binding Proteins / Q000502:physiology*; D017353:Gene Deletion; D005786:Gene Expression Regulation / Q000187:drug effects; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D006098:Granulocytes / Q000166:cytology*; D006410:Hematopoiesis / Q000187:drug effects / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D036341:Intercellular Signaling Peptides and Proteins; D007377:Interleukin-3 / Q000494:pharmacology; D000072100:Jagged-1 Protein; D008565:Membrane Proteins / Q000502:physiology*; D051379:Mice; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic / Q000187:drug effects; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000502:physiology; D051881:Receptor, Notch1; D011956:Receptors, Cell Surface; D011960:Receptors, Estrogen / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000502:physiology; D012045:Regulatory Sequences, Nucleic Acid; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction; D013629:Tamoxifen / Q000031:analogs & derivatives / Q000494:pharmacology; D014157:Transcription Factors; D015533:Transcriptional Activation
D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D036341:Intercellular Signaling Peptides and Proteins; D007377:Interleukin-3; C000606273:JAG1 protein, human; C000606274:Jag1 protein, mouse; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; C497761:NOTCH1 protein, human; C497762:Notch1 protein, mouse; D009687:Nuclear Proteins; D011506:Proteins; C497570:RBPJ protein, human; C497571:Rbpj protein, mouse; D051881:Receptor, Notch1; D011956:Receptors, Cell Surface; D011960:Receptors, Estrogen; D011993:Recombinant Fusion Proteins; D000072099:Serrate-Jagged Proteins; D014157:Transcription Factors; D013629:Tamoxifen; D016179:Granulocyte Colony-Stimulating Factor; C016601:afimoxifene