TRANSCRIPTION FACTOR AP-2 REGULATES HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 GENE-EXPRESSION

Human immunodeficiency virus type 1 (HIV-1) gene expression is regulat ed by an enhancer region composed of multiple potential cis-acting reg ulatory sites. Here, we describe binding sites for the transcription f actor AP-2 in the HIV-1 long terminal repeat which modulate HIV enhanc er function. One site is embedded within the two previously described kappa B elements, and a second site is detected further downstream. DN ase I footprinting and electrophoretic mobility shift assay experiment s demonstrated that AP-2 binds to the site between the kappa B element s. Interestingly, AP-2 and NF-kappa B bind to this region in a mutuall y exclusive manner. Mutations which disrupt this AP-2-binding site low er basal levels of transcription but do not affect NF-kappa B-mediated induction by tumor necrosis factor alpha in Jurkat T leukemia cells.