Differential repression of transcription factor binding by histone H1 is regulated by the core histone amino termini.
In order to investigate the interrelated roles of nucleosome cores and histone H1 in transcription repression, we have employed a purified system to analyze the function of H1 in the repression of transcription factor binding to nucleosomes. H1 binding to nucleosome cores resulted in the repression of USF binding to nucleosomes. By contrast, H1 only slightly inhibited the binding of GAL4-AH, indicating that H1 differentially represses the binding of factors with different DNA-binding domains. H1-mediated repression of factor binding was dependent on the core histone amino-terminal tails. Removal of these domains alleviated H1-mediated repression and increased acetylation of these domains partly alleviated repression by H1. H1 binding assays suggest a less stable interaction of histone H1 with the core particle in the absence of the amino termini.
Juan
L J
LJ
Center for Gene Regulation, Pennsylvania State University, University Park 16802-4500.
Utley
R T
RT
Adams
C C
CC
Vettese-Dadey
M
M
Workman
J L
JL
D000107:Acetylation; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006657:Histones / Q000494:pharmacology*; D006801:Humans; D008969:Molecular Sequence Data; D009707:Nucleosomes / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D029701:Saccharomyces cerevisiae Proteins; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000378:metabolism*; D051720:Upstream Stimulatory Factors
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D006657:Histones; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C497181:USF1 protein, human; D051720:Upstream Stimulatory Factors