title: Drosophila CTCF is required for Fab-8 enhancer blocking activity in S2 cells.
abstract: CTCF is a conserved transcriptional regulator with binding sites in DNA insulators identified in vertebrates and invertebrates. The Drosophila Abdominal-B locus contains CTCF binding sites in the Fab-8 DNA insulator. Previous reports have shown that Fab-8 has enhancer blocking activity in Drosophila transgenic assays. We now confirm the enhancer blocking capability of the Fab-8 insulator in stably transfected Drosophila S2 cells and show this activity depends on the Fab-8 CTCF binding sites. Furthermore, knockdown of Drosophila CTCF by RNAi in our stable cell lines demonstrates that CTCF itself is critical for Fab-8 enhancer blocking.
authors.affiliation: Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Dominic
authors.initials: D
authors.lastname: Ciavatta
authors.forename: Steve
authors.initials: S
authors.lastname: Rogers
authors.forename: Terry
authors.initials: T
authors.lastname: Magnuson
mesh_terms: D000818:Animals; D001665:Binding Sites; D000076246:CCCTC-Binding Factor; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D038101:Insulator Elements; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D034622:RNA Interference; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*