The E6 protein of human papillomavirus type 16 functions as a transcriptional repressor in a mechanism independent of the tumor suppressor protein, p53.
The E6 protein of human papillomavirus (HPV) type 16 displays a number of activities when transfected into cultured cells, including transcriptional activation of several viral promoters and targeting of p53 for degradation. HPV 16E6 was found to function as a transcriptional repressor of the moloney murine leukemia virus long terminal repeat and the cytomegalovirus immediate early promoter. Although the degree of transcriptional repression was low, a dose-dependent two- to threefold decrease in promoter activity was consistently seen in cells expressing 16E6. HPV 16E6-dependent transcriptional repression was observed in C33a cells, which express mutant p53, and in Saos-2 cells, which lack p53. These results indicate that 16E6-dependent repression of promoter activity is unlikely to be mediated by p53.
Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
B G
BG
Etscheid
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Foster
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Galloway
D000260:Adenoviruses, Human / Q000235:genetics; D002461:Cell Line, Transformed; D003587:Cytomegalovirus / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008979:Moloney murine leukemia virus / Q000235:genetics; D009856:Oncogene Proteins, Viral / Q000502:physiology*; D027383:Papillomaviridae; D011401:Promoter Regions, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000502:physiology*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000502:physiology
C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D012097:Repressor Proteins; D016159:Tumor Suppressor Protein p53