TY - JOUR
T1 - The role of the human papillomavirus type 18 E7 oncoprotein during the complete viral life cycle
AU - McLaughlin-Drubin, Margaret E.
AU - Bromberg-White, Jennifer L.
AU - Meyers, Craig
N1 - Funding Information:
We thank members of the Meyers' laboratory for many helpful discussions, Dr. H. zur Hausen for the HPV18 clone, and Lyn Budgeon for histological assistance. This work was supported by NIH Training grant 5 T32 60395-10 (M.M.-D.) and grant RO1 CA79006 (C.M.).
PY - 2005/7/20
Y1 - 2005/7/20
N2 - The role of the human papillomavirus oncoprotein E7 in carcinogenesis has been extensively studied. While the role of HPV E7 in the viral life cycle has also been studied, certain disparities exist, indicating that genotype differences may influence the role that E7 plays in the viral life cycle. In this study, we investigated the role of HPV18 E7 in the viral life cycle in order to gain a further understanding of this issue. To determine the role that HPV18 E7 plays in the viral life cycle, a translation termination substitution mutant of E7 in the context of the full HPV18 genome was created. We introduced linearized HPV18 E7-deficient genomic DNA into primary keratinocytes, where it recircularized and was maintained episomally at a range of five to several hundred copies of HPV genomic DNA. The mutant genomes failed to amplify following epithelial stratification and differentiation in organotypic culture. Moreover, virion morphogenesis did not occur. We found that the expression of HPV16 or HPV18 E7 in trans was able to rescue the amplification defect but not the defect in virion morphogenesis. These studies indicate that HPV18 E7 plays a critical role in the productive stage of the viral life cycle. In addition, these studies add further proof to the hypothesis that genotype differences exist for the role of E7 during the viral life cycle.
AB - The role of the human papillomavirus oncoprotein E7 in carcinogenesis has been extensively studied. While the role of HPV E7 in the viral life cycle has also been studied, certain disparities exist, indicating that genotype differences may influence the role that E7 plays in the viral life cycle. In this study, we investigated the role of HPV18 E7 in the viral life cycle in order to gain a further understanding of this issue. To determine the role that HPV18 E7 plays in the viral life cycle, a translation termination substitution mutant of E7 in the context of the full HPV18 genome was created. We introduced linearized HPV18 E7-deficient genomic DNA into primary keratinocytes, where it recircularized and was maintained episomally at a range of five to several hundred copies of HPV genomic DNA. The mutant genomes failed to amplify following epithelial stratification and differentiation in organotypic culture. Moreover, virion morphogenesis did not occur. We found that the expression of HPV16 or HPV18 E7 in trans was able to rescue the amplification defect but not the defect in virion morphogenesis. These studies indicate that HPV18 E7 plays a critical role in the productive stage of the viral life cycle. In addition, these studies add further proof to the hypothesis that genotype differences exist for the role of E7 during the viral life cycle.
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U2 - 10.1016/j.virol.2005.04.036
DO - 10.1016/j.virol.2005.04.036
M3 - Article
C2 - 15921717
AN - SCOPUS:20644458111
SN - 0042-6822
VL - 338
SP - 61
EP - 68
JO - Virology
JF - Virology
IS - 1
ER -