Targeted remodeling of human beta-globin promoter chromatin structure produces increased expression and decreased silencing.
The chromatin structure of the human beta-globin gene locus assumes a transcriptionally-active conformation in erythroid cells. One feature of this chromatin reorganization is the formation of DNase 1 hypersensitive sites in the regions of active globin gene promoters. This reorganization requires the globin locus control region and is associated with normal expression of the beta-like globin genes. To determine whether it is possible to artificially enhance the opening of the chromatin structure of a minimal beta-globin promoter, we placed a 101bp, erythroid-specific DNase 1 hypersensitive site-forming element (HSFE) immediately upstream of the beta-globin promoter and gene. This element includes binding sites for NF-E2, AP-1, GATA-1 and Sp-1. Constructs were stably transfected into murine erythroleukemia cells and promoter chromatin structure and gene expression were analyzed. The HSFE induced an area of enhanced DNase 1 hypersensitivity extending from the transcriptional start site to -300bp of the artificial promoter and significantly increased the proportion of beta-globin promoters in an open chromatin configuration. This remodeling of promoter chromatin structure resulted in 3-fold increases in beta-globin gene transcription and induction, and inhibited long-term beta-globin gene silencing. These results indicate that a relatively small cis-acting element is able to enhance remodeling of promoter chromatin structure resulting in increased beta-globin gene expression.
Iler
N
N
Department of Medicine, Dartmouth Medical School, Hanover, New Hampshire 03755, USA.
Goodwin
A J
AJ
McInerney
J
J
Nemeth
M J
MJ
Pomerantz
O
O
Layon
M E
ME
Lowrey
C H
CH
D002843:Chromatin / Q000235:genetics* / Q000648:ultrastructure; D004247:DNA / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D004912:Erythrocytes; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D005786:Gene Expression Regulation; D005914:Globins / Q000235:genetics*; D006801:Humans; D050983:NF-E2 Transcription Factor; D050984:NF-E2 Transcription Factor, p45 Subunit; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic
D002843:Chromatin; 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; D014157:Transcription Factors; D005914:Globins; D004247:DNA