Figure 5.

The proposed model for the interaction of Tat with SETDB1 and chromatin remodelers in HIV-1 transcription. This model depicts the role of Tat in the involvement of activating transcription and chromatin remodeling. Tat is shown interacting with Cdk9/cyclinT to bind to the TAR secondary structure element to initiate transcription. This binding complex recruits CBP/p300 which acetylates Tat, dissociates from the complex, and associates with SWI/SNF and p/CAF to facilitate transcriptional elongation. The repressive complex is shown with Tat being methylated by SETDB1, which may interact with DNA methyltransferase 3A and recruits HDAC to promote a compacted heterochromatin structure possibly at the 3' end of the HIV-1 genome.