HIV-1 Nef protein inhibits the recruitment of AP-1 DNA-binding activity in human T-cells.
The human immunodeficiency virus type 1 long terminal repeat, HIV-1-LTR, contains binding sites for several cellular transcription factors which contribute to HIV-1 gene expression. Our previous studies on the function of the HIV-1-encoded Nef protein suggested that Nef may be an inhibitor HIV-1 transcription. To determine whether Nef affects the binding of cellular factors implicated in HIV-1 regulation, 32P-labeled oligonucleotides corresponding to the binding sites were incubated with nuclear extracts prepared from Nef-expressing T-cell lines that were not stimulated or were stimulated with T-cell mitogens. We found that Nef inhibited the recruitment of AP-1 DNA-binding activity in mitogen-stimulated human T-cells. Additionally, Nef expressing cells were transiently transfected with a plasmid in which HIV-1 AP-1 DNA recognition sequences were cloned downstream of the chloramphenicol acetyltransferase (CAT) gene. Mitogen-mediated transcriptional activation of the CAT gene in this construct was inhibited in Nef-expressing cells but not in control cells. These studies suggest that, by inhibiting AP-1 activation, Nef may play a role in regulating HIV-1 gene expression in infected T-cells.
Niederman
T M
TM
Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
Hastings
W R
WR
Luria
S
S
Bandres
J C
JC
Ratner
L
L
D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D003001:Cloning, Molecular; D004274:DNA, Recombinant; D015967:Gene Expression Regulation, Viral; D015693:Gene Products, nef / Q000378:metabolism*; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008213:Lymphocyte Activation; D008934:Mitogens; D008969:Molecular Sequence Data; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D013601:T-Lymphocytes / Q000382:microbiology; D014158:Transcription, Genetic; D054311:nef Gene Products, Human Immunodeficiency Virus
D004274:DNA, Recombinant; D015693:Gene Products, nef; D008934:Mitogens; D016755:Proto-Oncogene Proteins c-jun; D054311:nef Gene Products, Human Immunodeficiency Virus; D015500:Chloramphenicol O-Acetyltransferase