Figure 5.

Complex between the trans-activating responsive RNA element TAR, viral (Tat), and cell proteins (cyclin T1, CDK-9) is required for efficient transcription of the HIV-1 genome. Disruption of this complex leads to abortive transcription of the retroviral DNA. A high-affinity RNA hairpin aptamer (R06) specifically recognizes TAR. The transcription of a R06 construct in recipient cells reduces the production of β-galactosidase whose expression is driven by the HIV-1 promoter containing TAR, in response to retroviral infection. Therefore, targeting RNA hairpins offers an alternative to targeting proteins for the design of artificial modulators of gene expression.