title: Mapping and characterization of DNase I hypersensitive sites in Arabidopsis chromatin.
abstract: Recent genome-wide analyses of yeast and human chromatin revealed the widespread prevalence of DNase I hypersensitive sites (DNase I HSs) at gene regulatory regions with possible roles in eukaryotic gene regulation. The presence of DNase I HSs in plants has been described for only a few genes, and we analyzed the chromatin structure of an 80 kb genomic region containing 30 variably expressed genes by DNase I sensitivity assay at 500 bp resolution in Arabidopsis. Distinct DNase I HSs were found at the 5' and/or 3' ends of most genes irrespective of their expression levels. Further analysis of well-characterized genes showed that the DNase I HSs occurred near cis-regulatory elements in the promoters of these genes. Upon transcriptional activation of a heat-inducible gene, the DNase I HS was extended into the vicinity of a cis-element and adjacent TATA element in the promoter. Concomitant with this change in DNase I HS, histones were acetylated, removed from the promoter, and a transcription activator bound to this cis-element. These results suggest that the DNase I HSs participate in the transcriptional regulation of Arabidopsis genes by enhancing the access of chromatin remodeling factors and/or transcription factors to their target sites as seen in yeast and human chromatin.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kodama
authors.forename: Shingo
authors.initials: S
authors.lastname: Nagaya
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Shinmyo
authors.forename: Ko
authors.initials: K
authors.lastname: Kato
mesh_terms: D000107:Acetylation; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism*; D002874:Chromosome Mapping; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D003850:Deoxyribonuclease I; D017343:Genes, Plant; D018745:Genome, Plant; D006360:Heat-Shock Proteins / Q000235:genetics; D006657:Histones / Q000378:metabolism; D011401:Promoter Regions, Genetic; D015533:Transcriptional Activation
chemical_list: D029681:Arabidopsis Proteins; D002843:Chromatin; D017931:DNA Primers; D018744:DNA, Plant; C446287:HSP18.2 protein, Arabidopsis; D006360:Heat-Shock Proteins; D006657:Histones; D003850:Deoxyribonuclease I