Date of Award
Doctor of Philosophy (PhD)
Professor S.T. Bayley
The polypeptides specified by the transforming region of the Adenovirus 5 (Ad 5) genome have been studied by immunoprecipitating antigens (using the double antibody and protein A-Sepharose methods) from cells transformed by Ad 5 and from cells infected with Ad 5 wild type (wt) or host range mutants. Three different antisera were used: P antiserum specific for early viral products (Russel et al, 1967) and two hamster tumor antisera. With both the double antibody and protein A-Sepharose methods, all three antisera immunoprecipitated a 58,000 dalton polypeptide from wt-infected KB cells, while P antiserum precipitated additional polypeptides of molecular weight 72,000, 67,000 and 44,000. When the double antibody method was used, P antiserum and the hamster tumor antisera also immunoprecipitated a 10,500 dalton protein which was not observed with the protein A-Sepharose method. The Ad 5 hr mutants fall into two complementation groups designated I and II, both of which exhibit defective transformation activity (Harrison et al, 1977; Graham et al, 1979). In group I mutant infected cells, little 10,500 dalton protein was observed relative to that found with wt infected cells, whereas very little or no 58,000 dalton polypeptide was immunoprecipitated from cells infected with mutants from complementation group II. Since a 58,000 dalton antigen was also found in a number of Ad 5 transformed cell lines, but was not detected in the cells infected with transformation defective group II mutants, it was concluded that the 58,000 dalton protein may be involved in the induction and/or maintenance of transformation.
Collett and Erikson (1978) have reported that the transformation gene product of Rous sarcoma virus is associated with protein kinase activity. Studies were undertaken to determine whether similar activity was also associated with the tumor antigens of Ad 5. The products immunoprecipitated from wt Ad 5 infected cells using tumor antisera were found to catalyse the transfer of ³²P from (γ-³²P) ATP into protein. Very little of this activity was observed with extracts from mock infected cells or when non-immune sera were used. The Ad 5 hr mutants were found to induce less protein kinase activity than wt virus. Evidence is presented suggesting that this activity is associated with early viral functions. Protein kinase activity was also detected in immunoprecipitates from Ad 5-transformed rat cells.
Lassam, Norman John Errington, "Studies on Tumor Antigens of Adenovirus Type 5" (1980). Open Access Dissertations and Theses. Paper 597.