Histone H1 enhances synergistic activation of the MMTV promoter in chromatin.
Minichromosomes assembled on the mouse mammary tumor virus (MMTV) promoter in vitro exhibit positioned nucleosomes, one of which covers the binding sites for progesterone receptor (PR) and nuclear factor 1 (NF1). Incorporation of histone H1 into MMTV minichromosomes improves the stability of this nucleosome and decreases basal transcription from the MMTV promoter, as well as its response to either PR or NF1. However, histone H1-containing minichromosomes display better PR binding and support a more efficient synergism between PR and NF1, leading to enhanced transcription initiation. A mutant MMTV promoter lacking positioned nucleosomes does not display enhanced transcriptional synergism in the presence of H1. Binding of PR leads to phosphorylation of H1, which leaves the promoter upon transcription initiation. Thus, H1 assumes a complex and dynamic role in the regulation of the MMTV promoter.
Koop
Ronald
R
Institut für Molekularbiologie und Tumorforschung (IMT), Philipps-Universität, E.-Mannkopff-Strasse 2, D-35033 Marburg, Germany.
Di Croce
Luciano
L
Beato
Miguel
M
D000818:Animals; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism*; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D004331:Drosophila melanogaster / Q000502:physiology; D015967:Gene Expression Regulation, Viral; D006657:Histones / Q000378:metabolism*; D006801:Humans; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D009707:Nucleosomes / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011980:Receptors, Progesterone / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013552:Swine; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D002843:Chromatin; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D006657:Histones; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D009707:Nucleosomes; D011980:Receptors, Progesterone; D011994:Recombinant Proteins; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human