title: Rapid and selective remodeling of a positioned nucleosome during the induction of IL-12 p40 transcription.
abstract: Nucleosomes are important for gene regulation, but comprehensive studies of nucleosome positioning, remodeling, and transcription factor binding at inducible mammalian promoters have not been reported. We have analyzed the IL-12 p40 promoter, which is induced in macrophages by bacterial products. High-resolution micrococcal nuclease analyses revealed that a positioned nucleosome, nucleosome 1, spans the promoter, with three positioned nucleosomes further upstream. Upon activation, nucleosome 1 was rapidly and selectively remodeled in a protein synthesis-dependent manner. In primary macrophages, IFNgamma synergistically enhanced p40 expression, but little effect on remodeling or promoter occupancy was observed. These results suggest that remodeling complexes are selectively targeted to a single, promoter-encompassing nucleosome and that IFNgamma influences an event that is independent or downstream of remodeling.
authors.affiliation: Howard Hughes Medical Institute, Department of Microbiology, Immunology, and Molecular Genetics, University of California, 90095-1662, USA.
authors.forename: A S
authors.initials: AS
authors.lastname: Weinmann
authors.forename: S E
authors.initials: SE
authors.lastname: Plevy
authors.forename: S T
authors.initials: ST
authors.lastname: Smale
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D015870:Gene Expression; D018664:Interleukin-12 / Q000235:genetics*; D008264:Macrophages / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D008836:Micrococcal Nuclease / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D009707:Nucleosomes; D018664:Interleukin-12; D008836:Micrococcal Nuclease