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Full-Text Articles in Life Sciences
Simian Virus 40 Host Range/Helper Function Mutations Cause Multiple Defects In Viral Late Gene Expression., Terryl Stacy, Michele Chamberlain, Charles N. Cole
Simian Virus 40 Host Range/Helper Function Mutations Cause Multiple Defects In Viral Late Gene Expression., Terryl Stacy, Michele Chamberlain, Charles N. Cole
Dartmouth Scholarship
Simian virus 40 (SV40) deletion mutants dlA2459 and dlA2475 express T antigens that lack the normal carboxy terminus. These mutants are called host range/helper function (hr/hf) mutants because they form plaques at 37 degrees C on BSC-1 and Vero monkey kidney cell lines but not on CV-1p monkey kidney cells. Wild-type SV40 can provide a helper function to permit growth of human adenoviruses in monkey kidney cells; the hr/hf mutants cannot. Progeny yields of hr/hf mutants are also cold sensitive in all cell lines tested. Patterns of viral macromolecular synthesis in three cell lines (Vero, BSC-1, and CV-1) at three …
Regulation Of Queuine Insertion Into Transfer Rna: Effects Of Tumor Promoters, Bonnie Jean Brooks
Regulation Of Queuine Insertion Into Transfer Rna: Effects Of Tumor Promoters, Bonnie Jean Brooks
Chemistry & Biochemistry Theses & Dissertations
The purpose of this study was to treat normal human fibroblasts with known tumor promoters and observe queuine modification of tRNA. The queuine insertion enzyme, tRNAguanine ribosyltransferase, was studied in vivo and in vitro. Tumor promoter-treated human fibroblast cultures exhibited variable queuine-insertion rates with a transient inhibition that correlated with variable levels of queuine modified tRNA over time in culture from passages 3 — 8. In contrast the in vitro studies showed that phorbol cetera and saccharin actually increased insertion with strong evidence indicating phosphorylation as a positive modulating force of the enzyme activity. It is proposed that chronic stimulation …