Journal article
The expression and properties of polyoma virus middle-T antigen in simian cells
Biochemistry Division, National Institute for Medical Research, Mill Hill, London NW7 1AA, U.K.
SV40 late replacement vectors containing the polyoma middle-T coding sequences have been constructed. Mixed hybrid virus stocks have been obtained through complementation with a defective SV40 helper genome (dl 1055) following DNA transfection into CV-1 cells. Middle-T antigen is expressed in the infected simian cells at about 5-10 fold higher levels than in polyoma virus-infected mouse cells and has the pp60c-src-associated tyrosine-specific protein kinase activity in vitro.
However, the 'specific activity' of the kinase in extracts of the infected CV-1 cells is lower than that observed in polyoma infected 3T6 cell extracts. The half-life of middle-T antigen in the CV-1 cells is about 4 h but the in vitro kinase activity associated with middle-T has a half-life of at least 8 h and hence appears to be stabilized.
The in vivo phosphorylated species of middle-T has been shown by sucrose gradient analyses to be largely distinct from the middle-T with associated protein kinase activity in vitro.
| Language: | English |
|---|---|
| Year: | 1986 |
| Pages: | 157-177 |
| ISSN: | 09212590 , 01681702 and 18727492 |
| Types: | Journal article |
| DOI: | 10.1016/0168-1702(86)90039-0 |
| ORCIDs: | Belsham, G J |
Animals Antigens, Polyomavirus Transforming Antigens, Viral, Tumor Cell Line DNA Restriction Enzymes DNA, Viral Electrophoresis, Polyacrylamide Gel Genetic Vectors Half-Life Haplorhini Nucleic Acid Hybridization Oncogene Proteins, Viral Phosphorylation Plasmids Polyomavirus Protein-Tyrosine Kinases SV40 expression vector Simian virus 40 protein phosphorylation tyrosine-specific protein kinase
