Host-specificities of papillomavirus, Moloney murine sarcoma virus and simian virus 40 enhancer sequences.
AUTOR(ES)
Spandidos, D A
RESUMO
The bovine papillomavirus (BPV-1), Moloney murine sarcoma virus (MoMuSV) and simian virus 40(SV40) genomes have been shown to contain sequences termed 'enhancers' which activate the expression of linked genes. DNA fragments containing these three enhancers have been inserted into recombinant plasmids upstream from the herpes simplex virus thymidine kinase (tk) gene, and their effect on tk expression monitored. Two types of assay have been used. Firstly, the ability of recombinant plasmids to transform TK- recipient cells to a TK+ phenotype was measured. Secondly, the amount of tk-specific RNA and TK enzyme activity transiently expressed after DNA transfection was determined. Both types of assay gave similar results. The enhancers increased tk gene expression by regulating the amount of full length tk mRNA present shortly after transfection independent of gene copy number. Furthermore, marked species specificity in the relative efficiencies of different enhancers was observed, including that of the BPV-1 enhancer for the first time. The MoMuSV enhancer showed preference for murine fibroblasts, while the papillomavirus enhancer showed a marked preference for bovine cells. In contrast, the SV40 enhancer gave the same relative increase in tk gene expression in the murine, rat, bovine and human cells tested.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=555255Documentos Relacionados
- Host-specific activation of transcription by tandem repeats from simian virus 40 and Moloney murine sarcoma virus.
- Replication-competent Moloney murine leukemia virus carrying a bacterial suppressor tRNA gene: selective cloning of proviral and flanking host sequences.
- Analysis of a transgenic mouse containing simian virus 40 and v-myc sequences.
- Characterization of enhancer elements in the long terminal repeat of Moloney murine sarcoma virus.
- Addition of substitution of simian virus 40 enhancer sequences into the Moloney murine leukemia virus (M-MuLV) long terminal repeat yields infectious M-MuLV with altered biological properties.