Histone replacement marks the boundaries of cis-regulatory domains.
Cellular memory is maintained at homeotic genes by cis-regulatory elements whose mechanism of action is unknown. We have examined chromatin at Drosophila homeotic gene clusters by measuring, at high resolution, levels of histone replacement and nucleosome occupancy. Homeotic gene clusters display conspicuous peaks of histone replacement at boundaries of cis-regulatory domains superimposed over broad regions of low replacement. Peaks of histone replacement closely correspond to nuclease-hypersensitive sites, binding sites for Polycomb and trithorax group proteins, and sites of nucleosome depletion. Our results suggest the existence of a continuous process that disrupts nucleosomes and maintains accessibility of cis-regulatory elements.
Mito
Yoshiko
Y
Basic Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109, USA.
Henikoff
Jorja G
JG
Henikoff
Steven
S
D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D002843:Chromatin / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D004268:DNA-Binding Proteins / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster; D005801:Genes, Homeobox; D017344:Genes, Insect; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D006657:Histones / Q000378:metabolism*; D005810:Multigene Family; D009687:Nuclear Proteins / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D063150:Polycomb Repressive Complex 1; D063151:Polycomb Repressive Complex 2; D011485:Protein Binding; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000378:metabolism; D020218:Response Elements; D014157:Transcription Factors / Q000378:metabolism
D002843:Chromatin; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018840:HSP70 Heat-Shock Proteins; D006657:Histones; D009687:Nuclear Proteins; D009707:Nucleosomes; D012097:Repressor Proteins; D014157:Transcription Factors; C063460:Trl protein, Drosophila; C060849:z protein, Drosophila; C071050:Psc protein, Drosophila; C083329:E(z) protein, Drosophila; D063151:Polycomb Repressive Complex 2; D063150:Polycomb Repressive Complex 1