title: Rapid periodic binding and displacement of the glucocorticoid receptor during chromatin remodeling.
abstract: An ultrafast UV laser crosslinking assay has provided novel insights into the progression of the SWI/SNF-mediated chromatin-remodeling reaction and transcription factor binding in real time. We demonstrate site-specific crosslinking between the glucocorticoid receptor (GR), the hSWI/SNF chromatin-remodeling complex, and the mouse mammary tumor virus (MMTV) promoter assembled in an array of correctly positioned nucleosomes. GR first demonstrates rapid binding to the promoter and then is actively displaced from the template during the remodeling reaction. This displacement reaction requires the hSWI/SNF complex and ATP, is specific to the nucleoprotein template, and is accompanied by a core histone rearrangement. The hSWI/SNF complex associates with random positions on the chromatin template in the absence of GR but is recruited specifically to the B/C region when GR is included. These results indicate that enhancement of hSWI/SNF-mediated factor accessibility, a hallmark of chromatin remodeling, is in some cases transient, reversible, and periodic.
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, Building 41, B602, 41 Library Drive, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Akhilesh K
authors.initials: AK
authors.lastname: Nagaich
authors.forename: Dawn A
authors.initials: DA
authors.lastname: Walker
authors.forename: Ron
authors.initials: R
authors.lastname: Wolford
authors.forename: Gordon L
authors.initials: GL
authors.lastname: Hager
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002843:Chromatin / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004265:DNA Helicases; D004591:Electrophoresis, Polyacrylamide Gel; D005557:Formaldehyde / Q000378:metabolism; D015967:Gene Expression Regulation, Viral; D018390:Gene Targeting; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D007834:Lasers; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D009687:Nuclear Proteins / Q000378:metabolism; D009707:Nucleosomes / Q000737:chemistry / Q000378:metabolism; D017354:Point Mutation; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D013698:Templates, Genetic; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D002843:Chromatin; D003432:Cross-Linking Reagents; D006657:Histones; D009687:Nuclear Proteins; D009707:Nucleosomes; D011965:Receptors, Glucocorticoid; D014157:Transcription Factors; D005557:Formaldehyde; D000255:Adenosine Triphosphate; D004247:DNA; C084108:SMARCA4 protein, human; C513194:Smarca4 protein, mouse; D004265:DNA Helicases