Induction of the HPV16 enhancer activity by Jun-B and c-Fos through cooperation of the promoter-proximal AP-1 site and the epithelial cell type--specific regulatory element in fibroblasts.
The epithelial cell type-specific enhancer of the human papillomavirus (HPV) type 16 termed the long control region (LCR) carries three AP-1 binding sites. We investigated the roles of the AP-1 sites for transactivation of the LCR by Jun-B that may be a cell type specific-transactivator for the HPVs in human fibroblasts in which expression of the endogenous Jun-B gene is low. Transient expression of Jun-B alone poorly activated transcriptional activity of the LCR. However, when combined with c-Fos, Jun-B activated the LCR. The promoter-proximal AP-1 site was required for transactivation of the LCR by Jun-B:c-Fos, but the site itself was not sufficient for the maximal response. The proposed cell type specific--regulatory element that harbors binding sites for NF1 as well as TEF-1 and PEA3 motifs, but neither other AP-1 sites nor the proximal enhancer region, could augment the transcriptional response of the promoter-proximal AP-1 site to Jun-B:c-Fos.
Kikuchi
K
K
Laboratory of Molecular and Cellular Biology, Kanagawa Cancer Center Research Institute, Yokohama, Japan.
Taniguchi
A
A
Yasumoto
S
S
D002460:Cell Line; D004279:DNA, Viral; D004742:Enhancer Elements, Genetic; D004848:Epithelium; D005347:Fibroblasts / Q000166:cytology; D015967:Gene Expression Regulation, Viral; D006367:HeLa Cells; D006801:Humans; D027383:Papillomaviridae / Q000235:genetics*; D011401:Promoter Regions, Genetic; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics*; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D018808:Transcription Factor AP-1 / Q000235:genetics*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D004279:DNA, Viral; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1