Mutational analysis of the HIV-1 LTR as a promoter of negative sense transcription.
The HIV-1 gene promoter is a bi-directional promoter of transcription. We report the characterization of the negative sense promoter (NSP) by analysis of the effect on negative sense transcription of a series of LTR U3 region substitution mutants. Mutations in the region nt -58 to -183 (positive sense transcription initiation nt +1) reduced transcription to <15% of wild type NSP activity. This region, essential for NSP activity, was designated the core basal promoter. Over expression of NF-kappaB RelA(p65) and LEF-1 increased negative sense expression, as did over expression of H-ras oncogene, consistent with the presence of cognate sequence motifs for NF-kappaB, LEF-1 and RBF. We were also able to confirm that the NSP is a TATA-less promoter inhibited by HIV-1 Tat. Based on our findings, we propose a model for the interaction between the NSP and PSP, and the role of Tat in regulating the interaction.
Bentley
K
K
AIDS Molecular Biology Unit, National Centre for HIV Virology Research, Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Australia.
Deacon
N
N
Sonza
S
S
Zeichner
S
S
Churchill
M
M
D004252:DNA Mutational Analysis; D015536:Down-Regulation; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D015696:Gene Products, tat / Q000502:physiology; D016325:HIV Long Terminal Repeat / Q000235:genetics / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D019169:Jurkat Cells; D009154:Mutation / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology*; D015854:Up-Regulation; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D014157:Transcription Factors; D054322:tat Gene Products, Human Immunodeficiency Virus