An element upstream from the human delta-globin-encoding gene specifically enhances beta-globin reporter gene expression in murine erythroleukemia cells.
We have previously shown that a DNA-binding factor specific to adult hematopoietic cells (polypryrimidine-binding factor, PYBF) binds to a pyrimidine-rich region 1 kb upstream from the human delta-globin-encoding gene (HBD). The developmental stage-specificity of PYBF and the location of its binding site between the fetal and adult beta-globin (HBB)-like genes suggest that PBYF and its binding site may function in fetal-to-adult globin gene switching. Here, we describe the effect of 383-bp (delta383) and 99-bp (delta99) sequences containing the PYBF-binding site on transcription from various globin and non-globin promoters, using a transient assay with the cat reporter gene in murine erythroleukemia (MEL) cells, a cell line with abundant PYBF activity. We show that both delta383 and delta99 specifically enhance expression of cat for plasmids containing a human adult globin (HBB) promoter, whereas expression of similar constructs using human fetal (A gamma-) globin (HBG1) or simian virus 40 (SV40) promoters is not enhanced. The results suggest that PYBF and the pyrimidine-rich region upstream from HBD can specifically enhance HBB transcription in adult erythroid cells.
Acuto
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Unita di Ricerca, Piera Cutino, Ospedale V. Cervello, Palermo, Italy.
Urzi
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G
Schimmenti
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S
Maggio
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A
O'Neill
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D
Bank
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A
D000328:Adult; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D002878:Chromosomes, Human, Pair 1; D004268:DNA-Binding Proteins / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D050981:Erythroid-Specific DNA-Binding Factors; D005319:Fetal Hemoglobin / Q000235:genetics; D005333:Fetus; D015870:Gene Expression; D005914:Globins / Q000096:biosynthesis / Q000235:genetics*; D006441:Hemoglobin A / Q000235:genetics; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute; D051379:Mice; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D013539:Simian virus 40 / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D014157:Transcription Factors; D005914:Globins; D006441:Hemoglobin A; D005319:Fetal Hemoglobin