title: Blockers and barriers to transcription: competing activities?
abstract: In the eukaryotic cell active and inactive genes reside adjacent to one another and are modulated by numerous regulatory elements. Insulator elements prevent the misregulation of adjacent genes by restricting the effects of the regulatory elements to specific domains. Enhancer blockers prevent enhancers from inadvertently activating neighboring genes, and recent results suggest that they might function by a conserved mechanism across species. These elements appear to disrupt enhancer-promoter "communications" by interacting with the regulatory elements and sequestering these elements into specific regions of the nucleus thus rendering them non-functional. Barrier elements insulate active genes from neighboring heterochromatin and recent results suggest that they function by specific localized recruitment of acetyltransferases that antagonize the spread of heterochromatin-associated deacetylases, thus preventing the propagation of heterochromatin.
authors.affiliation: Unit on Chromatin and Transcription, NICHD, Building 18T, Room 106, 18 Library Drive, Bethesda, MD 20892, USA.
authors.forename: Masaya
authors.initials: M
authors.lastname: Oki
authors.forename: Rohinton T
authors.initials: RT
authors.lastname: Kamakaka
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins / Q000502:physiology; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D020868:Gene Silencing; D008957:Models, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins