title: Nucleosome occupancy reveals regulatory elements of the CFTR promoter.
abstract: Access to regulatory elements of the genome can be inhibited by nucleosome core particles arranged along the DNA strand. Hence, sites that are accessible by transcription factors may be located by using nuclease digestion to identify the relative nucleosome occupancy of a genomic region. In order to define novel cis regulatory elements in the ∼2.7-kb promoter region of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, we define its nucleosome occupancy. This profile reveals the precise positions of nucleosome-free regions (NFRs), both cell-type specific and others apparently unrelated to CFTR-expression level and offer the first high-resolution map of the chromatin structure of the entire CFTR promoter in relevant cell types. Several of these NFRs are strongly bound by nuclear factors in a sequence-specific manner, and directly influence CFTR promoter activity. Sequences within the NFR1 and NFR4 elements are highly conserved in many human gene promoters. Moreover, NFR1 contributes to promoter activity of another gene, angiopoietin-like 3 (ANGPTL3), while NFR4 is constitutively nucleosome-free in promoters genome wide. Conserved motifs within NFRs of the CFTR promoter also show a high level of protection from DNase I digestion genome-wide, and likely have important roles in the positioning of nucleosome core particles more generally.
authors.affiliation: Human Molecular Genetics Program, Children's Memorial Research Center, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60614, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Ott
authors.forename: Jared M
authors.initials: JM
authors.lastname: Bischof
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Unti
authors.forename: Austin E
authors.initials: AE
authors.lastname: Gillen
authors.forename: Shih-Hsing
authors.initials: SH
authors.lastname: Leir
authors.forename: Ann
authors.initials: A
authors.lastname: Harris
mesh_terms: D001483:Base Sequence; D002478:Cells, Cultured; D017124:Conserved Sequence; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D009707:Nucleosomes / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D009707:Nucleosomes; D014157:Transcription Factors; D019005:Cystic Fibrosis Transmembrane Conductance Regulator