Transcriptional regulation of papillomavirus gene products on phospholipase C-gamma 1 promoter region

Abstract

Transcriptional regulation of Human Papillomaviruses (HPV) gene products - E2, E6 and E7 proteins on PhospholipaseCg1 (PLC-$\gamma$1) promoter region was studied employing CAT assay. PLC-$\gamma$1 promoter can be divided into three parts according to patterns of transcriptional regulation. The upstream regulatory region of PLC-$\gamma$1 promoter (-1034 $\sim$ -672) is supposed to control the overall transcriptional activities, while the middle part (-672 $\sim$ -551), designated as positive regulatory region, which is believed to be the binding sites of strong transcriptional activation factors, shows strong transcriptional activity. The downstream minimal promoter region (-551 $\sim$ +114) also revealed basal transcriptional activity. HPV E2 transcription activator protein was observed no significant effect on the transcriptional regulation of PLC-$\gamma$1 promoter. This result is well coincident with the lack of E2 binding site in PLC-$\gamma$1 promoter region. HPV E6 oncoproteinwas found to be a positive regulator of the transcriptional activity in most of PLC-$\gamma$1 promoter regions. However, the effect of HPV E7 oncoprotein on the PLC-$\gamma$1 promoter activity differs by the region of PLC-$\gamma$1 promoter. HPV E7 exerts little effect to the upstream regulatory region of the PLC-$\gamma$1 promoter, with decreased the transcriptional activity in the positive regulatory region and increased the activity in the downstream minimal promoter region.