NF-kappa B-mediated chromatin reconfiguration and transcriptional activation of the HIV-1 enhancer in vitro.
NF-kappa B is a potent inducible transcription factor that regulates many genes in activated T cells. In this report we examined the ability of different subunits of NF-kappa B to enhance HIV-1 transcription in vitro with chromatin templates. We find that the p65 subunit of NF-kappa B is a strong transcriptional activator of nucleosome-assembled HIV-1 DNA, whereas p50 does not activate transcription, and that p65 activates transcription synergistically with Sp1 and distal HIV-1 enhancer-binding factors (LEF-1, Ets-1, and TFE-3). These effects were observed with chromatin, but not with nonchromatin templates. Furthermore, binding of either p50 or p65 with Sp1 induces rearrangement of the chromatin to a structure that resembles the one reported previously for integrated HIV-1 proviral DNA in vivo. These results suggest that p50 and Sp1 contribute to the establishment of the nucleosomal arrangement of the uninduced provirus in resting T cells, and that p65 activates transcription by recruitment of the RNA polymerase II transcriptional machinery to the chromatin-repressed basal promoter.
Pazin
M J
MJ
Department of Biology, University of California, San Diego (UCSD), La Jolla 92093-0347, USA.
Sheridan
P L
PL
Cannon
K
K
Cao
Z
Z
Keck
J G
JG
Kadonaga
J T
JT
Jones
K A
KA
D001483:Base Sequence; D001665:Binding Sites; D002843:Chromatin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics; D015967:Gene Expression Regulation, Viral; D016322:HIV Enhancer / Q000235:genetics*; D016325:HIV Long Terminal Repeat; D006367:HeLa Cells; D006801:Humans; D051821:Lymphoid Enhancer-Binding Factor 1; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D052002:NF-kappa B p50 Subunit; D009707:Nucleosomes / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators; D051996:Transcription Factor RelA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D002843:Chromatin; D004268:DNA-Binding Proteins; C497573:LEF1 protein, human; D051821:Lymphoid Enhancer-Binding Factor 1; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D009707:Nucleosomes; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D051996:Transcription Factor RelA; D014157:Transcription Factors