Alterations in protein-DNA interactions in the gamma-globin gene promoter in response to butyrate therapy
| Autor: | T, Ikuta, Y W, Kan, P S, Swerdlow, D V, Faller, S P, Perrine |
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| Rok vydání: | 1998 |
| Předmět: |
Adult
Adolescent Base Sequence Erythroblasts Transcription Genetic Molecular Sequence Data beta-Thalassemia DNA Footprinting Anemia Sickle Cell DNA Middle Aged Regulatory Sequences Nucleic Acid Globins DNA-Binding Proteins Butyrates Gene Expression Regulation Child Preschool Humans RNA Messenger Child Promoter Regions Genetic Fetal Hemoglobin Protein Binding Transcription Factors |
| Zdroj: | Blood. 92(8) |
| ISSN: | 0006-4971 |
| Popis: | The mechanisms by which pharmacologic agents stimulate gamma-globin gene expression in beta-globin disorders has not been fully established at the molecular level. In studies described here, nucleated erythroblasts were isolated from patients with beta-globin disorders before and with butyrate therapy, and globin biosynthesis, mRNA, and protein-DNA interactions were examined. Expression of gamma-globin mRNA increased twofold to sixfold above baseline with butyrate therapy in 7 of 8 patients studied. A 15% to 50% increase in gamma-globin protein synthetic levels above baseline gamma globin ratios and a relative decrease in beta-globin biosynthesis were observed in responsive patients. Extensive new in vivo footprints were detected in erythroblasts of responsive patients in four regions of the gamma-globin gene promoter, designated butyrate-response elements gamma 1-4 (BRE-G1-4). Electrophoretic mobility shift assays using BRE-G1 sequences as a probe demonstrated that new binding of two erythroid-specific proteins and one ubiquitous protein, alphaCP2, occurred with treatment in the responsive patients and did not occur in the nonresponder. The BRE-G1 sequence conferred butyrate inducibility in reporter gene assays. These in vivo protein-DNA interactions in human erythroblasts in which gamma-globin gene expression is being altered strongly suggest that nuclear protein binding, including alphaCP2, to the BRE-G1 region of the gamma-globin gene promoter mediates butyrate activity on gamma-globin gene expression. |
| Databáze: | OpenAIRE |
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