Abstract
E4bp4, a member of the basic region/leucine zipper transcription factor superfamily, is up-regulated by the interleukin-3 (IL-3) signaling pathway and plays an important role in the anti-apoptotic response of IL-3. In this study, we demonstrated that E4bp4 is regulated by IL-3 mainly at the transcriptional level. Promoter analysis revealed that a GATA motif downstream of a major transcription initiation site is essential for E4bp4 expression in the IL-3-dependent Ba/F3 cell line. Gel shift assays demonstrated that both GATA-1 and GATA-2 proteins bind to the E4bp4 GATA site in vitro, and the chromatin immunoprecipitation assay further confirmed the in vivo binding of GATA-1 to the E4bp4 promoter. Overexpression of GATA-1 alone transactivates the E4bp4 reporter, whereas transactivation of the E4bp4 reporter by GATA-2 is dependent on the stimulation of IL-3. Last, we demonstrated that alteration of GATA-1 binding to the GATA site by stably overexpressing GATA-1 or a GATA-1 mutant containing only the DNA-binding domain not only modulates the expression of the E4bp4 gene but also influences apoptosis induced by IL-3 removal. Taken together, our results suggest that the GATA factors play an important role in transducing the survival signal of IL-3, and one of their cellular targets is E4bp4.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Apoptosis
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Base Sequence
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Basic-Leucine Zipper Transcription Factors
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Blotting, Northern
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Blotting, Western
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Cell Survival
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Chromatin / metabolism
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Chromosome Mapping
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Cloning, Molecular
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DNA / metabolism
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DNA-Binding Proteins / genetics*
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DNA-Binding Proteins / metabolism
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DNA-Binding Proteins / physiology*
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Electroporation
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Erythroid-Specific DNA-Binding Factors
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G-Box Binding Factors
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GATA1 Transcription Factor
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GATA2 Transcription Factor
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Genes, Reporter
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Hematopoietic Stem Cells / metabolism
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Interleukin-3 / metabolism*
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Luciferases / metabolism
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Mice
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Models, Genetic
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Molecular Sequence Data
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Plasmids / metabolism
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Precipitin Tests
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Promoter Regions, Genetic
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Protein Binding
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Protein Structure, Tertiary
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RNA, Messenger / metabolism
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Signal Transduction
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Single-Strand Specific DNA and RNA Endonucleases / metabolism
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Time Factors
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Transcription Factors / genetics*
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Transcription Factors / metabolism
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Transcription Factors / physiology*
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Transcription, Genetic*
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Transcriptional Activation
Substances
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Basic-Leucine Zipper Transcription Factors
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Chromatin
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DNA-Binding Proteins
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Erythroid-Specific DNA-Binding Factors
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G-Box Binding Factors
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GATA1 Transcription Factor
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GATA2 Transcription Factor
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Gata1 protein, mouse
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Gata2 protein, mouse
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Interleukin-3
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Nfil3 protein, mouse
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RNA, Messenger
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Transcription Factors
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DNA
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Luciferases
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Single-Strand Specific DNA and RNA Endonucleases