Enhanced activity of human G6PD promoter transfected in HeLa cells producing high levels of HIV-1 Tat.
Glucose 6-phosphate dehydrogenase (G6PD) enzyme activity has an important role in the cell defence against oxidative damage produced by hydrogen peroxide, a compound known to activate HIV-1 expression through the intermediate of NF-kappa B. By means of CAT assays, in this paper we show that the Tat protein increases the rate of transcription from the human G6PD promoter in HeLa cells; furthermore, we report a similar effect of Tat on transcription driven from the viral RSV promoter. We did not observe Tat stimulation with the human CMV, SV40 or the basic RSV promoters. Dose-response curves indicate that Tat activates G6PD and RSV through a mechanism different from the major one operating on the HIV-1 LTR promoter. TAR-like structures are not involved, instead a short sequence close to the G6PD transcription start site and the RSV LTR enhancer is a good candidate for mediating the phenomena described in this paper. This sequence has some features in common with the NF-kappa B motif.
Ursini
M V
MV
Istituto Internazionale di Genetica e Biofisica, CNR, Napoli, Italy.
Lettieri
T
T
Braddock
M
M
Martini
G
G
D001483:Base Sequence; D004279:DNA, Viral; D015696:Gene Products, tat / Q000096:biosynthesis / Q000235:genetics*; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D015497:HIV-1 / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014162:Transfection; D054322:tat Gene Products, Human Immunodeficiency Virus
D004279:DNA, Viral; D015696:Gene Products, tat; D054322:tat Gene Products, Human Immunodeficiency Virus; D005954:Glucosephosphate Dehydrogenase