title: GATA-1-dependent transcriptional repression of GATA-2 via disruption of positive autoregulation and domain-wide chromatin remodeling.
abstract: Interplay among GATA transcription factors is an important determinant of cell fate during hematopoiesis. Although GATA-2 regulates hematopoietic stem cell function, mechanisms controlling GATA-2 expression are undefined. Of particular interest is the repression of GATA-2, because sustained GATA-2 expression in hematopoietic stem and progenitor cells alters hematopoiesis. GATA-2 transcription is derepressed in erythroid precursors lacking GATA-1, but the underlying mechanisms are unknown. Using chromatin immunoprecipitation analysis, we show that GATA-1 binds a highly restricted upstream region of the approximately 70-kb GATA-2 domain, despite >80 GATA sites throughout the domain. GATA-2 also binds this region in the absence of GATA-1. Genetic complementation studies in GATA-1-null cells showed that GATA-1 rapidly displaces GATA-2, which is coupled to transcriptional repression. GATA-1 also displaces CREB-binding protein (CBP), despite the fact that GATA-1 binds CBP in other contexts. Repression correlates with reduced histone acetylation domain-wide, but not altered methylation of histone H3 at lysine 4. The GATA factor-binding region exhibited cell-type-specific enhancer activity in transient transfection assays. We propose that GATA-1 instigates GATA-2 repression by means of disruption of positive autoregulation, followed by establishment of a domain-wide repressive chromatin structure. Such a mechanism is predicted to be critical for the control of hematopoiesis.
authors.affiliation: Molecular and Cellular Pharmacology Program, Department of Pharmacology, University of Wisconsin Medical School, 383 Medical Sciences Center, 1300 University Avenue, Madison, WI 53706, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Grass
authors.forename: Meghan E
authors.initials: ME
authors.lastname: Boyer
authors.forename: Saumen
authors.initials: S
authors.lastname: Pal
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Mitchell J
authors.initials: MJ
authors.lastname: Weiss
authors.forename: Emery H
authors.initials: EH
authors.lastname: Bresnick
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D050989:GATA2 Transcription Factor; D006410:Hematopoiesis; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; C494689:Gata1 protein, mouse; C494712:Gata2 protein, mouse; D006657:Histones; D012097:Repressor Proteins; D014157:Transcription Factors; D004247:DNA