The promoter and enhancer of the inactive chicken beta-globin gene contains precisely positioned nucleosomes.
Core histone octamers reconstituted in vitro onto DNA fragments containing the chicken beta-globin gene promoter are precisely positioned with respect to the underlying DNA sequence [1]. Here we show that this is also true of the chicken beta-globin gene enhancer. These nucleosome binding sites are also employed within transfected COS cell nuclei, where the chicken beta-globin gene is transcriptionally inactive. Similar results were found in vivo, where positioned nucleosomes were detected over the inactive beta-globin promoter in chicken brain cells and 5-day red blood cells, and over the inactive beta-globin enhancer in brain cells. In contrast, the promoter and enhancer regions were found to be nucleosome-free in 15-day erythrocytes where the beta-globin gene is active. We argue that these results suggest a role for positioned nucleosomes in the regulation of the transcription of the chicken beta-globin gene.
Buckle
R
R
Department of Biophysics, Cell and Molecular Biology, King's College, London, UK.
Balmer
M
M
Yenidunya
A
A
Allan
J
J
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002645:Chickens; D004587:Electrophoresis, Agar Gel; D004742:Enhancer Elements, Genetic; D005090:Exodeoxyribonucleases; D005914:Globins / Q000235:genetics*; D008969:Molecular Sequence Data; D009707:Nucleosomes / Q000378:metabolism*; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012313:RNA / Q000302:isolation & purification; D015183:Restriction Mapping; D014158:Transcription, Genetic; D014162:Transfection
D009707:Nucleosomes; D012313:RNA; D005914:Globins; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III