title: Globin gene activation during haemopoiesis is driven by protein complexes nucleated by GATA-1 and GATA-2.
abstract: How does an emerging transcriptional programme regulate individual genes as stem cells undergo lineage commitment, differentiation and maturation? To answer this, we have analysed the dynamic protein/DNA interactions across 130 kb of chromatin containing the mouse alpha-globin cluster in cells representing all stages of differentiation from stem cells to mature erythroblasts. The alpha-gene cluster appears to be inert in pluripotent cells, but priming of expression begins in multipotent haemopoietic progenitors via GATA-2. In committed erythroid progenitors, GATA-2 is replaced by GATA-1 and binding is extended to additional sites including the alpha-globin promoters. Both GATA-1 and GATA-2 nucleate the binding of various protein complexes including SCL/LMO2/E2A/Ldb-1 and NF-E2. Changes in protein/DNA binding are accompanied by sequential alterations in long-range histone acetylation and methylation. The recruitment of polymerase II, which ultimately leads to a rapid increase in alpha-globin transcription, occurs late in maturation. These studies provide detailed evidence for the more general hypothesis that commitment and differentiation are primarily driven by the sequential appearance of key transcriptional factors, which bind chromatin at specific, high-affinity sites.
authors.affiliation: MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Anguita
authors.forename: Jim
authors.initials: J
authors.lastname: Hughes
authors.forename: Clare
authors.initials: C
authors.lastname: Heyworth
authors.forename: Gerd A
authors.initials: GA
authors.lastname: Blobel
authors.forename: William G
authors.initials: WG
authors.lastname: Wood
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Higgs
mesh_terms: D000107:Acetylation; D000818:Animals; D001665:Binding Sites; D002454:Cell Differentiation; D019070:Cell Lineage; D002843:Chromatin / Q000378:metabolism; D004257:DNA Polymerase II / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015672:Erythroid Precursor Cells / Q000378:metabolism; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D050989:GATA2 Transcription Factor; D018507:Gene Expression Regulation, Developmental; D005914:Globins / Q000235:genetics*; D006410:Hematopoiesis; D006657:Histones / Q000378:metabolism; D007739:L Cells; D008745:Methylation; D051379:Mice; D008954:Models, Biological; D050983:NF-E2 Transcription Factor; D050984:NF-E2 Transcription Factor, p45 Subunit; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D016335:Zinc Fingers
chemical_list: D002843:Chromatin; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D050989:GATA2 Transcription Factor; C494689:Gata1 protein, mouse; C494712:Gata2 protein, mouse; D006657:Histones; D050983:NF-E2 Transcription Factor; D050984:NF-E2 Transcription Factor, p45 Subunit; C494693:Nfe2 protein, mouse; D009687:Nuclear Proteins; D011506:Proteins; D014157:Transcription Factors; D005914:Globins; D004257:DNA Polymerase II