Bovine (B) papillomavirus (PV) type 1, which is genetically related to human (H) and all other PVs, is the best studied model of PVs in vitro. The BPV E6 gene fully transforms mouse cells and the analogous E6 genes of HPVs are preferentially expressed in HPV associated carcinomas. Utilizing antisera to bacterially expressed BPV E6, this protein was identified in nuclear and membrane fractions of BPV transformed cells. This represented the first non-structural protein identified for any PV. The goals of this proposal are to identify the corresponding E6 gene products of HPVs and to biologically and functionally characterize the E6 proteins. The E6 gene of several HPVs, in particular those most commonly found in human cancers, will be cloned into a bacterial expression vector, antisera made and the gene products identified and characterized via an analgous approach. Other studies planned include the analysis of the metabolism and localization of E6 in transformed cells and papillomas, and the testing for biochemical activities such as binding to other viral or cellular proteins or DNA. The biochemical properties of the BPV E6 protein will be tested in BPV E6 mutants and correlated with the biological consequences of the mutation. To facilitate these studies, a panel of monoclonal antibodies will be generated to the BPV E6 protein. Monoclonals to HPV E6 proteins will also be developed; in addition to their utility for experiments in this protocol they may be of utility in the diagnosis and characterization of PV containing dysplasias and carcinomas. These studies should contribute to elucidating the mechanisms of PV induced transformation and tumorigenesis.
