Repression of the human papillomavirus type 18 enhancer by the cellular transcription factor Oct-1.
AUTOR(ES)
Hoppe-Seyler, F
RESUMO
The role of cellular factors involved in the transcriptional regulation of the cancer-associated human papillomavirus type 18 (HPV18) is yet poorly understood. The presence of an Oct-1-binding site within the HPV18 upstream regulatory region led us to investigate the influence of Oct-1 on viral transcription. Cotransfection of Oct-1 expression plasmids together with luciferase reporter constructs containing HPV18 regulatory sequences indicated that Oct-1 can transcriptionally repress the HPV18 upstream regulatory region. In contrast, heterologous control regions were not affected by Oct-1. HPV18 cis elements that can be repressed by Oct-1 mapped to a 135-bp subregion of the viral constitutive enhancer. Analysis of an Oct-1 mutant defective in DNA binding suggested that HPV18 down-modulation does not require direct binding of Oct-1 to DNA. These results make Oct-1 a candidate factor involved in the intracellular surveillance of HPV18 transcription and support the notion of a host cell mechanism that can specifically repress HPV E6-E7 transforming gene expression.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=249079Documentos Relacionados
- The enhancer in the long control region of human papillomavirus type 16 is up-regulated by PEF-1 and down-regulated by Oct-1.
- Activation of human papillomavirus type 18 E6-E7 oncogene expression by transcription factor Sp1.
- Repression of bovine papillomavirus type 1 transcription by the E1 replication protein.
- The enhancer of human papillomavirus type 16: binding sites for the ubiquitous transcription factors oct-1, NFA, TEF-2, NF1, and AP-1 participate in epithelial cell-specific transcription.
- Inducible and constitutive enhancer domains in the noncoding region of human papillomavirus type 18.
