scholarly journals Simian virus 40 (SV40) T-antigen transcriptional activation mediated through the Oct/SPH region of the SV40 late promoter.

1991 ◽  
Vol 65 (7) ◽  
pp. 3553-3558 ◽  
Author(s):  
M C Gruda ◽  
J C Alwine
Keyword(s):  
Transcriptional Activation ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Late Promoter ◽  
Sv40 T Antigen

Replication of cloned DNA containing the Alu family sequence during cell extract-promoting simian virus 40 DNA synthesis

1984 ◽  
Vol 4 (8) ◽  
pp. 1476-1482
Author(s):  
H Ariga
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Rna Polymerase Iii ◽  
Simian Virus 40 ◽  
Cell Extract ◽  
Simian Virus ◽  
T Antigen ◽  
Sv40 T Antigen ◽  
Sv40 Dna

The replicating activity of several cloned DNAs containing putative origin sequences was examined in a cell-free extract that absolutely depends on simian virus 40 (SV40) T antigen promoting initiation of SV40 DNA replication in vitro. Of the three DNAs containing the human Alu family sequence (BLUR8), the origin of (Saccharomyces cerevisiae plasmid 2 micron DNA (pJD29), and the yeast autonomous replicating sequence (YRp7), only BLUR8 was active as a template. Replication in a reaction mixture with BLUR8 as a template was semiconservative and not primed by a putative RNA polymerase III transcript synthesized on the Alu family sequence in vitro. Pulse-chase experiments showed that the small-sized DNA produced in a short-term incubation was converted to full-length closed circular and open circular DNAs in alkaline sucrose gradients. DNA synthesis in extracts began in a region of the Alu family sequence and was inhibited 80% by the addition of anti-T serum. Furthermore, partially purified T antigen bound the Alu family sequence in BLUR8 by the DNA-binding immunoassay. These results suggest that SV40 T antigen recognizes the Alu family sequence, similar to the origin sequence of SV40 DNA, and initiates semiconservative DNA replication in vitro.

Downstream sequences affect transcription initiation from the adenovirus major late promoter

1986 ◽  
Vol 6 (7) ◽  
pp. 2684-2694 ◽  
Author(s):  
S L Mansour ◽  
T Grodzicker ◽  
R Tjian
Keyword(s):  
Transcription Initiation ◽  
Simian Virus 40 ◽  
T Antigen ◽  
Control Element ◽  
Coding Region ◽  
Late Promoter ◽  
Sv40 T Antigen ◽  
Transient Expression Assay ◽  
Adenovirus Major Late Promoter ◽  
Major Late Promoter

We analyzed a set of adenovirus-simian virus 40 (SV40) hybrids in which the SV40 T antigen coding sequences are inserted downstream from the adenovirus major late promoter within the first, second, and third segments of the tripartite leader. In infected cells, these viruses give rise to a matched set of hybrid SV40 mRNAs that differ only in the number of tripartite leader segments attached to the complete SV40 T antigen coding region. We found that the number of tripartite leader segments present at the 5' end of the hybrid SV40 mRNAs had little effect on the efficiency of T antigen translation. Surprisingly, insertion of SV40 sequences within the first leader segment, at +33 relative to the start of transcription, significantly reduced the frequency of transcription initiation from the major late promoter. The 3' boundary of this downstream transcriptional control element was mapped between +33 and +190 by showing that insertion of SV40 sequences within the intron after the first leader segment at +190 had very little effect on transcription initiation from the late promoter. A transient expression assay was used to show that the effect of downstream sequences on transcription initiation from the major late promoter is dependent on a trans-acting factor encoded or induced by adenovirus.

Antibody response to human papovavirus JC (JCV) and simian virus 40 (SV40) T antigens in SV40 T antigen-transgenic mice

Virology ◽  
1992 ◽  
Vol 190 (1) ◽  
pp. 459-464 ◽  
Author(s):  
Satvir S. Tevethia ◽  
Melanie Epler ◽  
Ingo Georgoff ◽  
Angie Teresky ◽  
Marty Marlow ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Antibody Response ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Sv40 T Antigen ◽  
T Antigens ◽  
Human Papovavirus

scholarly journals Downstream sequences affect transcription initiation from the adenovirus major late promoter.

1986 ◽  
Vol 6 (7) ◽  
pp. 2684-2694 ◽  
Author(s):  
S L Mansour ◽  
T Grodzicker ◽  
R Tjian
Keyword(s):  
Transcription Initiation ◽  
Simian Virus 40 ◽  
T Antigen ◽  
Control Element ◽  
Coding Region ◽  
Late Promoter ◽  
Sv40 T Antigen ◽  
Transient Expression Assay ◽  
Adenovirus Major Late Promoter ◽  
Major Late Promoter

We analyzed a set of adenovirus-simian virus 40 (SV40) hybrids in which the SV40 T antigen coding sequences are inserted downstream from the adenovirus major late promoter within the first, second, and third segments of the tripartite leader. In infected cells, these viruses give rise to a matched set of hybrid SV40 mRNAs that differ only in the number of tripartite leader segments attached to the complete SV40 T antigen coding region. We found that the number of tripartite leader segments present at the 5' end of the hybrid SV40 mRNAs had little effect on the efficiency of T antigen translation. Surprisingly, insertion of SV40 sequences within the first leader segment, at +33 relative to the start of transcription, significantly reduced the frequency of transcription initiation from the major late promoter. The 3' boundary of this downstream transcriptional control element was mapped between +33 and +190 by showing that insertion of SV40 sequences within the intron after the first leader segment at +190 had very little effect on transcription initiation from the late promoter. A transient expression assay was used to show that the effect of downstream sequences on transcription initiation from the major late promoter is dependent on a trans-acting factor encoded or induced by adenovirus.

scholarly journals Simian virus 40 (SV40)-transgenic mice that develop tumors are specifically tolerant to SV40 T antigen.

1987 ◽  
Vol 165 (2) ◽  
pp. 417-427 ◽  
Author(s):  
S J Faas ◽  
S Pan ◽  
C A Pinkert ◽  
R L Brinster ◽  
B B Knowles
Keyword(s):  
Immune Tolerance ◽  
Transgenic Line ◽  
Simian Virus 40 ◽  
Humoral Response ◽  
Simian Virus ◽  
T Antigen ◽  
T Cell Response ◽  
Cytotoxic T Cell ◽  
Sv40 T Antigen ◽  
Transgenic Lines

The ability to mount an immune response to simian virus 40 (SV40) T antigen was evaluated using mice from two distinct SV40 transgenic lines derived from injection of the same gene construct. Our studies demonstrate functional immune tolerance to SV40 T antigen in a SV40 transgenic line that consistently develops tumors of the choroid plexus by 7 mo of age. Antibodies to SV40 T antigen are undetectable in the serum of these animals; furthermore, mice from this line are unable to generate SV40-specific CTL after primary or secondary immunization with the virus, although they mount a normal CTL response to vaccinia virus when appropriately immunized. In contrast, we find that mice from a second transgenic line of low tumor incidence can mount a humoral response to SV40 T antigen, and upon immunization they generally respond with a vigorous cytotoxic T cell response to SV40 T antigen. These data suggest that specific immune tolerance to the product of an integrated viral oncogene may be induced, and is likely a reflection of the time in development at which the gene product first appears. Immune tolerance or responsiveness to the endogenous oncogene product may in turn play a role in the tumorigenic potential of such genes.

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