Functional similarities between HIV-1 Tat and DNA sequence-specific transcriptional activators.
The Tat regulatory protein encoded by human immunodeficiency virus type 1 (HIV-1) induces high levels of transcription from the viral long terminal repeat (LTR) promoter element after interacting with a promoter proximal RNA target sequence. In the wild-type HIV-1 LTR, this activation is facilitated by the synergistic interaction of Tat with the NF-kappa B and, particularly, SP1 regulatory proteins that bind to DNA sequences within the LTR promoter element. Using a synthetic Tat responsive indicator construct, we here demonstrate that NF-kappa B and SP1 are not uniquely or even unusually competent to synergize with HIV-1 Tat. Instead, these proteins can be functionally replaced by several, but not all, of the heterologous cellular and viral transcriptional activators tested. Tat therefore shares the ability to functionally synergize with a range of transcriptional activators, which is characteristic of DNA-sequence-specific regulatory proteins.
Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710.
S J
SJ
Madore
B R
BR
Cullen
D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D002522:Chlorocebus aethiops; D003587:Cytomegalovirus / Q000235:genetics / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism*; D015696:Gene Products, tat / Q000378:metabolism*; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007668:Kidney; D016328:NF-kappa B / Q000378:metabolism; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D054322:tat Gene Products, Human Immunodeficiency Virus
D004279:DNA, Viral; D015696:Gene Products, tat; D016328:NF-kappa B; D011993:Recombinant Fusion Proteins; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D054322:tat Gene Products, Human Immunodeficiency Virus