Transcriptional regulation of the HIV-1 promoter by NF-kappa B in vitro.
NF-kappa B, purified from HeLa cell cytosol, and a recombinant p50 subunit of NF-kappa B alone (expressed in and purified from bacteria) both stimulated transcription from the HIV-1 promoter in vitro (at least up to 15-fold). A deletion analysis of the p50 subunit revealed that transcriptional activation was mediated by the conserved c-rel-related domain. I kappa B-beta (or a related protein), which binds to the p65 but not the p50 subunit of NF-kappa B, inhibited stimulation by natural NF-kappa B but not by recombinant p50. Experiments employing a purified transcription system revealed that efficient induction of transcription by both natural NF-kappa B or recombinant p50 required a cofactor fraction in addition to the general initiation factors. Combined with DNA-binding experiments, these studies suggest a role of p50 homodimers in transcriptional activation of certain promoters, with a possible preference for those carrying symmetric NF-kappa B recognition sites, and a potential role of I kappa B-beta in direct transcriptional regulation within the nucleus.
Kretzschmar
M
M
Laboratory of Biochemistry and Molecular Biology, Rockefeller University, New York, New York 10021.
Meisterernst
M
M
Scheidereit
C
C
Li
G
G
Roeder
R G
RG
D001483:Base Sequence; D015153:Blotting, Western; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015967:Gene Expression Regulation, Viral / Q000235:genetics; D015497:HIV-1 / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D020672:I-kappa B Proteins; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism; D052002:NF-kappa B p50 Subunit; D011401:Promoter Regions, Genetic / Q000235:genetics; D011498:Protein Precursors / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*
D004268:DNA-Binding Proteins; C083487:I kappa B beta protein; D020672:I-kappa B Proteins; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D011498:Protein Precursors; D011994:Recombinant Proteins; D014157:Transcription Factors