Globin gene switching. In vivo protein-DNA interactions of the human beta-globin locus in erythroid cells expressing the fetal or the adult globin gene program.
To characterize the protein-DNA interactions important for the developmental control of the human beta-globin locus, we analyzed by in vivo dimethyl sulfate footprinting erythroid cells expressing either the fetal or the adult globin developmental program. In the locus control region (LCR) of the beta-globin locus, in vivo footprints on NF-E2 (or AP-1) and GATA-1 motifs remained the same regardless of whether the fetal or the adult globin genes are expressed. In contrast, in vivo footprints on GT (CACCC) motifs differed between the cells expressing the fetal or the adult globin program. In promoter regions, the actively transcribed genes demonstrated extensive and consistent footprints over the canonical elements, such as CACCC and CCAAT motifs. The adult globin expressing cells displayed more extensive footprints than the fetal globin expressing cells in the 3' regulatory sequences of both the Agamma- and the beta-globin genes, suggesting a role of these 3' elements in beta-globin gene expression. Our results suggest that the bulk of protein-DNA interactions that underlies the developmental control of globin genes takes place in the gamma- and beta-globin gene promoters, and that GT motifs of the beta-globin locus LCR may play a role in the developmental regulation of human beta-globin gene expression, perhaps by increasing the probability of interaction of the LCR holocomplex with the fetal or the adult globin gene.
Ikuta
T
T
Department of Laboratory Medicine and Howard Hughes Medical Institute, University of California, San Francisco, California 94143, USA.
Papayannopoulou
T
T
Stamatoyannopoulos
G
G
Kan
Y W
YW
D000328:Adult; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D018983:DNA Footprinting; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D005319:Fetal Hemoglobin / Q000096:biosynthesis*; D005333:Fetus; D050982:GATA1 Transcription Factor; D005914:Globins / Q000096:biosynthesis* / Q000235:genetics*; D006441:Hemoglobin A / Q000096:biosynthesis*; D006801:Humans; D006822:Hybrid Cells; D008969:Molecular Sequence Data; D050983:NF-E2 Transcription Factor; D050984:NF-E2 Transcription Factor, p45 Subunit; D016133:Polymerase Chain Reaction; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D016335:Zinc Fingers
D017931:DNA Primers; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D050983:NF-E2 Transcription Factor; D050984:NF-E2 Transcription Factor, p45 Subunit; C494692:NFE2 protein, human; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D005914:Globins; D006441:Hemoglobin A; D005319:Fetal Hemoglobin