Binding of HMG 17 to mononucleosomes of the avian beta-globin gene cluster in erythroid and non-erythroid cells.
The binding of HMG 17 to stripped core mononucleosomes containing DNA from the avian beta-globin gene cluster was examined to determine whether binding in vitro in this developmentally-regulated gene domain was associated with transcriptional activity or DNaseI-sensitivity in intact nuclei. Mononucleosomes were prepared from primitive and definitive stage embryonic red blood cells of chick embryos, adult reticulocytes, adult reticulocytes in which embryonic rho-globin transcription was induced, and adult thymus cells. Preferential binding by HMG 17 to mononucleosomes containing the beta-globin gene cluster was confined to erythroid-derived mononucleosomes that contain the embryonic rho-globin gene, the adult beta-globin gene, and DNA sequences located between these two genes, but not to those that contain the embryonic epsilon-globin gene. Comparison of these results to the known patterns of transcription and DNaseI-sensitivity within the beta-globin gene cluster shows that HMG 17 binding, although tissue-specific, does not correlate directly with either DNaseI-sensitivity or active gene transcription, but is dependent on other factors present in core mononucleosomes from this active gene domain.
Department of Internal Medicine, University of Iowa College of Medicine, Iowa City.
T W
TW
Brotherton
J
J
Reneker
G D
GD
Ginder
D000818:Animals; D001374:Azacitidine / Q000494:pharmacology; D002087:Butyrates / Q000494:pharmacology; D002642:Chick Embryo; D002645:Chickens; D004247:DNA / Q000032:analysis; D004912:Erythrocytes / Q000378:metabolism*; D005914:Globins / Q000235:genetics*; D006609:High Mobility Group Proteins / Q000378:metabolism*; D005810:Multigene Family; D009707:Nucleosomes / Q000032:analysis / Q000378:metabolism*; D012156:Reticulocytes / Q000378:metabolism; D014158:Transcription, Genetic
D002087:Butyrates; D006609:High Mobility Group Proteins; D009707:Nucleosomes; D005914:Globins; D004247:DNA; D001374:Azacitidine