Although the HIV-1 long terminal repeat (LTR) contains four potential binding sites for the octamer-binding protein, Oct-1, which is known to interact with the HIV-1 Tat protein, the effect of the Oct-1 factor on HIV LTR-driven gene expression has not previously been reported. We show here that both Oct-1, and to a lesser extent the related Oct-2 protein, can repress both the basal activity of the HIV-1 LTR and its transactivation by Tat. These effects are still observed with an HIV LTR construct containing only a single octamer-binding site located between the TATA box and the transcriptional start site. The stronger inhibitory effect of Oct-1 on both these promoters is dependent upon its C-terminal region which cannot be effectively replaced by the equivalent region of Oct-2. These effects are discussed in terms of the regulation of HIV LTR activity in different cell types and in response to T-cell activation.
The octamer-binding proteins Oct-1 and Oct-2 repress the HIV long terminal repeat promoter and its transactivation by Tat
- Views Icon Views
- PDF LinkPDF
- Share Icon Share
- Cite Icon Cite
Yu-Zhen LIU, David S. LATCHMAN; The octamer-binding proteins Oct-1 and Oct-2 repress the HIV long terminal repeat promoter and its transactivation by Tat. Biochem J 15 February 1997; 322 (1): 155–158. doi: https://doi.org/10.1042/bj3220155
Download citation file: