title: DNA methylation of intronic enhancers directs tissue-specific expression of steroidogenic factor 1/adrenal 4 binding protein (SF-1/Ad4BP).
abstract: The nuclear receptor steroidogenic factor 1/adrenal 4 binding protein (SF-1/Ad4BP) is an essential regulator of endocrine development and function, and the expression of the corresponding gene (sf-1/ad4bp) is precisely regulated in a time- and tissue-dependent manner. We previously demonstrated that the basal promoter of sf-1/ad4bp is controlled by DNA methylation and that its methylation status reflects the expression pattern of SF-1/Ad4BP. Recently, three intronic enhancers were identified in the sf-1/ad4bp gene that target SF-1/Ad4BP expression to the fetal adrenal (FAdE; fetal adrenal-specific enhancer), to pituitary gonadotropes (PGE; pituitary gonadotrope-specific enhancer), and to the ventromedial hypothalamic nucleus (VMHE; ventromedial hypothalamic nucleus-specific enhancer). Here, we demonstrate that the activity of these enhancers is correlated with their DNA methylation status. We show that they are hypomethylated in tissues where they are active and generally hypermethylated in tissues where they are not active. Furthermore, we demonstrate in transient transfection experiments that forced DNA methylation represses reporter gene activity driven by these enhancers. These data directly demonstrate a functional significance for the enhancers' methylation status. Intriguingly, further analyses of the basal promoter in gonadotropes revealed that it is methylated in these cells, in contrast to other SF-1/Ad4BP-expressing tissues. Consistent with this, sf-1/ad4bp is transcribed from an alternative promoter in gonadotropes. Taken together, our experiments show that the tissue-specific expression of SF-1/Ad4BP is epigenetically regulated and identify tissue-specific differentially methylated regions within the sf-1/ad4bp locus that are essential for its transcriptional control.
authors.affiliation: Department of Biomedicine, University of Bergen, Bergen, Norway.
authors.forename: Erling A
authors.initials: EA
authors.lastname: Hoivik
authors.forename: Trine E
authors.initials: TE
authors.lastname: Bjanesoy
authors.forename: Oliver
authors.initials: O
authors.lastname: Mai
authors.forename: Shiki
authors.initials: S
authors.lastname: Okamoto
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Minokoshi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Shima
authors.forename: Ken-Ichirou
authors.initials: K
authors.lastname: Morohashi
authors.forename: Ulrich
authors.initials: U
authors.lastname: Boehm
authors.forename: Marit
authors.initials: M
authors.lastname: Bakke
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D005260:Female; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D052681:Gonadotrophs / Q000378:metabolism; D007438:Introns / Q000235:genetics; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic / Q000235:genetics; D054339:Steroidogenic Factor 1 / Q000235:genetics*
chemical_list: D008164:Luminescent Proteins; D054339:Steroidogenic Factor 1