TRANSACTIVATION OF THE HUMAN PAPILLOMA VIRUS-16 OCTAMER MOTIF BY THE OCTAMER BINDING-PROTEIN OCT-2 REQUIRES BOTH THE N-TERMINAL AND C-TERMINAL ACTIVATION DOMAINS

The upstream regulatory region (URR) of the human papillomaviruses HPV 16 and 18 contains a sequence with a seven out of eight base match to the consensus binding site for octamer binding transcription factors. This motif acts as a target for repression by the Oct-1 transcription factor and therefore inhibits promoter activity in non-cervical cells expressing only Oct-1. In contrast the HPV octamer motif activates pro moter activity in cervical cells. Here we show that cervical cells exp ress the activating form of the Oct-2 transcription factor, Oct 2.1 an d that this factor can transactivate promoter activity via the HPV16 o ctamer. This effect is dependent upon both the N and C-terminal activa tion domains of Oct-2. The expression of specific octamer binding prot eins such as Oct-2 in cervical cells thus allows the HPV16 motif to pr oduce opposite effects on gene expression in cervical and non-cervical cells suggesting that it may play a role in the cervical specificity of URR driven gene expression.