Regulation of gene amplification and expression in cells that constitutively express a temperature sensitive SV40 T-antigen.
AUTOR(ES)
Portela, A
RESUMO
Simian cells have been transformed with SV40 origin-defective recombinant plasmids containing the tsA209 T-antigen gene. These plasmids contain deletions of either 5 or 52 nucleotides that include the BglI site at the SV40 ori, are defective for replication in COS-1 cells but retain a functional SV40 early promoter. Two cell lines transformed with these plasmids, U4 and S7, and their respective clonal derivatives E5 and F11, contain the tsA209 T-antigen gene integrated into the cell DNA and express T-antigen as detected by immunoprecipitation and immunofluorescence. These cells behave as ts-COS cells, since they complement in a temperature dependent manner the replication of an SV40 derived recombinant plasmid. When transfected with recombinant plasmids containing the chloramphenicol acetyl transferase (CAT) gene cloned into SV40 replicons, ts-COS cells were able to regulate the induction of the CAT activity by temperature. The ratios of CAT activity observed at permissive versus restrictive temperature were in the range of 20-400. Thus, these ts-COS cells are useful systems for the regulated expression of cloned genes in simian cells.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=322100Documentos Relacionados
- Localized melting and structural changes in the SV40 origin of replication induced by T-antigen.
- Binding studies of SV40 T-antigen to SV40 binding site II.
- Simian Virus 40-Host Cell Interactions. I. Temperature-Sensitive Regulation of SV40 T Antigen in 3T3 Mouse Cells Transformed by the ts*101 Temperature-Sensitive Early Mutant of SV40
- Trans-splicing and alternative-tandem-cis-splicing: two ways by which mammalian cells generate a truncated SV40 T-antigen.
- Transcriptional control of SV40 T-antigen expression allows a complete reversion of immortalization