Cell cycle regulation of nuclear factor p32 DNA-binding activity by novel phase-specific inhibitors.
The nuclear factor p92, originally discovered by its interaction with the human papillomavirus type 18 enhancer, is a cellular protein whose activity is restricted to S phase in human primary fibroblasts. The human papillomavirus type 18 p92 binding sequence confers enhancer activity on a heterologous promoter, suggesting that p92 acts as a transcription factor. We have identified a class of nuclear inhibitory proteins, I-92s, which noncovalently associate with p92 but not with other transcription factors such as AP1, E2F, or NF-kappaB. Different I-92s occur in G1, G2, and G0, while no I-92 is detectable in S phase. Phase-specific inhibitors, therefore, are responsible for the cell cycle dependence of p92 activity and provide a novel mechanism linking transcription factor regulation with the cell cycle.
Grinstein
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E
Department of Medical Genetics, Max-Delbrück Center for Molecular Medicine, Berlin, Germany.
Weinert
I
I
Droese
B
B
Pagano
M
M
Royer
H D
HD
D001483:Base Sequence; D001665:Binding Sites; D002453:Cell Cycle; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D005347:Fibroblasts; D005434:Flow Cytometry; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D027383:Papillomaviridae / Q000235:genetics; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D016196:S Phase; D013539:Simian virus 40 / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D014157:Transcription Factors