The Role of RNA Polymerase II Elongation Control in HIV-1 Gene Expression, Replication, and Latency

Figure 3

Tat overrides cellular elongation control. Tat interacts directly with P-TEFb sequestered in the 7SK snRNP. This results in a conformational change of 7SK, ejecting HEXIM proteins, and preventing P-TEFb•HEXIM1•7SK reassembly. Tat•P-TEFb migrates to the TAR element contained within HIV’s nascent transcript, binds, and acts upon DSIF and NELF, efficiently overcoming inhibition of transcription.