Transcription factor loading on the MMTV promoter: a bimodal mechanism for promoter activation.
The mouse mammary tumor virus (MMTV) promoter attains a phased array of six nucleosomes when introduced into rodent cells. This architecture excludes nuclear factor 1/CCAAT transcription factor (NF1/CTF) from the promoter before glucocorticoid treatment and hormone-dependent access of nucleolytic agents to promoter DNA. In contrast, when the promoter was transiently introduced into cells, NF1/CTF was bound constitutively and nucleolytic attack was hormone-independent. Thus, induction at this promoter was a bimodal process involving receptor-dependent remodeling of chromatin that allows NF1/CTF loading and direct receptor-mediated recruitment of additional transcription factors.
Hormone Action and Oncogenesis Section, Laboratory of Molecular Virology, National Cancer Institute, Bethesda, MD 20892.
T K
TK
Archer
P
P
Lefebvre
R G
RG
Wolford
G L
GL
Hager
D000818:Animals; D001483:Base Sequence; D022762:CCAAT-Enhancer-Binding Proteins; D004279:DNA, Viral / Q000502:physiology; D004268:DNA-Binding Proteins / Q000502:physiology; D003907:Dexamethasone / Q000494:pharmacology; D015967:Gene Expression Regulation, Viral; D005938:Glucocorticoids / Q000502:physiology; D066298:In Vitro Techniques; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics*; D008969:Molecular Sequence Data; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D009707:Nucleosomes / Q000502:physiology; D012150:Polymorphism, Restriction Fragment Length; D011401:Promoter Regions, Genetic / Q000502:physiology*; D015183:Restriction Mapping; D012377:Rodentia / Q000235:genetics*; D014157:Transcription Factors / Q000502:physiology*; D014162:Transfection; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D005938:Glucocorticoids; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D009707:Nucleosomes; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D003907:Dexamethasone