Open AccessTranscriptional repression at a distance through exclusion of activator binding in vivo
Author(s) -
Mitsuhiro Shimizu,
Weishi Li,
Heisaburo Shindo,
Aaron P. Mitchell
Publication year - 1997
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.94.3.790
Subject(s) - repressor , biology , transcription (linguistics) , binding site , microbiology and biotechnology , activator (genetics) , chromatin , footprinting , psychological repression , promoter , hypersensitive site , dna footprinting , nucleosome , deoxyribonuclease i , rna polymerase , rna polymerase ii , dna binding protein , dna , transcription factor , genetics , gene , rna , gene expression , linguistics , philosophy , base sequence
The yeast repressor Rme1p acts from distant binding sites to block transcription of the chromosomalIME1 gene. Rme1p can also repress the heterologousCYC1 promoter when Rme1p binding sites are placed 250–300 bp upstream ofCYC1 transcriptional activator binding sites (UAS1 and UAS2). Here,in vivo footprinting studies indicate that Rme1p acts over this distance by preventing the binding of theCYC1 transcriptional activators to UAS1 and UAS2. Inhibition of activator binding by Rme1p has the same genetic requirements as repression: both depend upon sequences flanking the Rme1p binding sites and upon Rgr1p and Sin4p, two subunits of the RNA polymerase II-associated Mediator complex that are required for normal nucleosome density. Thus Rme1p may alter chromatin to prevent binding of transcriptional activators to distant DNA sequences.