HIV Tat-specific factor 1 (HTATSF1)

Functions as a general transcription factor playing a role in the process of transcriptional elongation. May mediate the reciprocal stimulatory effect of splicing on transcriptional elongation.

In case of infection by HIV-1, it's up-regulated from the HIV-1 proteins NEF and gp120, functions as a cofactor necessary for the Tat-enhanced transcription of the virus. .