Characterization of the hematopoietic transcription factor NF-E2 in primary murine megakaryocytes.

Abstract

Biochemical analysis of megakaryocytes, the precursors of blood platelets, is limited by their rarity in vivo, and studies on lineage-specific gene expression have been conducted exclusively in cell lines with limited megakaryocytic potential. Mice lacking the transcription factor NF-E2 display arrested megakaryocyte differentiation and profound thrombocytopenia. To study the heterodimeric NF-E2 protein in primary cells, we cultured mouse fetal livers with the c-Mpl ligand, obtained highly enriched megakaryocyte populations, and readily detected NF-E2 activity in nuclear extracts. As in erythroid cells, p45 NF-E2 is the only large subunit in primary megakaryocytes that dimerizes with distinct small Maf proteins to constitute a heterogeneous NF-E2 complex. Whereas p18/MafK is the predominant small Maf protein in erythroid cells, the related polypeptides MafG and/or MafF predominate in megakaryocytes. Although this represents the first example of differential small Maf protein expression among closely related blood lineages, the DNA-binding specificity of NF-E2 is similar in both cell types. Although the megakaryocyte protein preferentially binds an asymmetric AP-1-related motif, it also recognizes cAMP-responsive element-related sequences, albeit with lower affinity, and nucleotides outside the core sequence influence the DNA-protein interaction. These results demonstrate the feasibility of biochemical studies on primary murine megakaryocytes and provide a basis to dissect the critical functions of NF-E2 in megakaryocyte differentiation.

• Authors: P Lecine, V Blank, R Shivdasani
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 273 Issue 13 Pg. 7572-8 (Mar 27 1998) ISSN: 0021-9258 [Print] United States
• PMID: 9516460 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• DNA-Binding Proteins
• Erythroid-Specific DNA-Binding Factors
• MafK Transcription Factor
• Mafk protein, mouse
• NF-E2 Transcription Factor
• NF-E2 Transcription Factor, p45 Subunit
• Nfe2 protein, mouse
• Nuclear Proteins
• Transcription Factors
• DNA
• Thrombopoietin

Topics

• Animals
• Base Sequence
• Binding Sites
• Cell Differentiation
• Culture Techniques
• DNA (chemistry, metabolism)
• DNA-Binding Proteins (metabolism)
• Erythroid-Specific DNA-Binding Factors
• Liver (embryology)
• MafK Transcription Factor
• Megakaryocytes (cytology, metabolism)
• Mice
• NF-E2 Transcription Factor
• NF-E2 Transcription Factor, p45 Subunit
• Nuclear Proteins (metabolism)
• Sequence Analysis, DNA
• Thrombopoietin (metabolism)
• Transcription Factors (metabolism)
• Tumor Cells, Cultured
• Zinc Fingers