title: The Human GATA1 Gene Retains a 5' Insulator That Maintains Chromosomal Architecture and GATA1 Expression Levels in Splenic Erythroblasts.
abstract: GATA1 is a key transcription factor for erythropoiesis. GATA1 gene expression is strictly regulated at the transcriptional level. While the regulatory mechanisms governing mouse Gata1 (mGata1) gene expression have been studied extensively, how expression of the human GATA1 (hGATA1) gene is regulated remains to be elucidated. To address this issue, we generated hGATA1 bacterial artificial chromosome (BAC) transgenic mouse lines harboring a 183-kb hGATA1 locus covering the hGATA1 exons and distal flanking sequences. Transgenic hGATA1 expression coincides with endogenous mGata1 expression and fully rescues hematopoietic deficiency in mGata1 knockdown mice. The transgene exhibited copy number-dependent and integration position-independent expression of hGATA1, indicating the presence of chromatin insulator activity within the transgene. We found a novel insulator element at 29 kb 5' to the hGATA1 gene and refer to this element as the 5' CCCTC-binding factor (CTCF) site. Substitution mutation of the 5' CTCF site in the hGATA1 BAC disrupted the chromatin architecture and led to a reduction of hGATA1 expression in splenic erythroblasts under conditions of stress erythropoiesis. Our results demonstrate that expression of the hGATA1 gene is regulated through the chromatin architecture organized by 5' CTCF site-mediated intrachromosomal interactions in the hGATA1 locus.
authors.affiliation: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan moriguch@med.tohoku.ac.jp masiyamamoto@med.tohoku.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Moriguchi
authors.affiliation: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.affiliation: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Takai
authors.affiliation: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Makiko
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Satoh
authors.affiliation: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Mikiko
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Pharmacy, Takasaki University of Health and Welfare, Takasaki, Japan.
authors.forename: Kinuko
authors.initials: K
authors.lastname: Ohneda
authors.affiliation: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan moriguch@med.tohoku.ac.jp masiyamamoto@med.tohoku.ac.jp.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D001665:Binding Sites; D000076246:CCCTC-Binding Factor; D002478:Cells, Cultured; D002843:Chromatin / Q000502:physiology; D002875:Chromosomes / Q000235:genetics*; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D004900:Erythroblasts / Q000378:metabolism*; D050982:GATA1 Transcription Factor / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D038101:Insulator Elements; D020014:K562 Cells; D051379:Mice; D008822:Mice, Transgenic; D012097:Repressor Proteins / Q000378:metabolism; D013154:Spleen / Q000166:cytology* / Q000378:metabolism
chemical_list: D000076246:CCCTC-Binding Factor; C000619697:CTCF protein, human; D002843:Chromatin; C000619698:Ctcf protein, mouse; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; C494689:Gata1 protein, mouse; D012097:Repressor Proteins