scholarly journals Stimulation of the adenovirus E2 promoter by simian virus 40 T antigen or E1A occurs by different mechanisms.

1986 ◽  
Vol 6 (6) ◽  
pp. 2020-2026 ◽  
Author(s):  
M R Loeken ◽  
G Khoury ◽  
J Brady
Keyword(s):  
Simian Virus 40 ◽  
Promoter Sequence ◽  
Simian Virus ◽  
Chloramphenicol Acetyltransferase ◽  
T Antigen ◽  
Base Pairs ◽  
Promoter Sequences ◽  
Adenovirus E1a ◽  
E1a Gene ◽  
Stimulation Of

We have examined the ability of simian virus 40 T antigen to stimulate transcription from the adenovirus E2 promoter. T antigen, produced from a cotransfected plasmid, stimulated chloramphenicol acetyltransferase enzyme and mRNA production from an E2 promoter-chloramphenicol acetyltransferase fusion plasmid (pEC113) in monkey kidney CV-1 cells. The level of stimulation of E2 transcription by simian virus 40 T antigen was equal to that observed in cotransfections of pEC113 and the adenovirus E1A gene product. Deletion mutations from the 5' end of the E2 promoter were examined for their ability to express basal, T-antigen, or E1A trans-activated promoter activity. In each case, deletion of upstream promoter sequences to -70 base pairs reduced chloramphenicol acetyltransferase expression to approximately 30% of the level observed with the intact E2 promoter. Deletion to -59 base pairs resulted in chloramphenicol acetyltransferase expression that was 3 to 5% of that observed with the intact E2 promoter. At saturating levels of the stimulatory proteins, the chloramphenicol acetyltransferase levels obtained in response to T antigen and adenovirus E1A were additive. COS-1 cells, which are derived from CV-1 cells and constitutively express simian virus 40 T antigen, do not support E2 promoter trans activation by T antigen. E1A trans activation of the E2 promoter is efficient in COS-1 cells. These results suggest that although promoter sequence requirements are similar, T antigen and E1A trans activate the E2 promoter by different mechanisms.

Stimulation of the adenovirus E2 promoter by simian virus 40 T antigen or E1A occurs by different mechanisms

1986 ◽  
Vol 6 (6) ◽  
pp. 2020-2026
Author(s):  
M R Loeken ◽  
G Khoury ◽  
J Brady
Keyword(s):  
Simian Virus 40 ◽  
Promoter Sequence ◽  
Simian Virus ◽  
Chloramphenicol Acetyltransferase ◽  
T Antigen ◽  
Base Pairs ◽  
Promoter Sequences ◽  
Adenovirus E1a ◽  
E1a Gene ◽  
Stimulation Of

We have examined the ability of simian virus 40 T antigen to stimulate transcription from the adenovirus E2 promoter. T antigen, produced from a cotransfected plasmid, stimulated chloramphenicol acetyltransferase enzyme and mRNA production from an E2 promoter-chloramphenicol acetyltransferase fusion plasmid (pEC113) in monkey kidney CV-1 cells. The level of stimulation of E2 transcription by simian virus 40 T antigen was equal to that observed in cotransfections of pEC113 and the adenovirus E1A gene product. Deletion mutations from the 5' end of the E2 promoter were examined for their ability to express basal, T-antigen, or E1A trans-activated promoter activity. In each case, deletion of upstream promoter sequences to -70 base pairs reduced chloramphenicol acetyltransferase expression to approximately 30% of the level observed with the intact E2 promoter. Deletion to -59 base pairs resulted in chloramphenicol acetyltransferase expression that was 3 to 5% of that observed with the intact E2 promoter. At saturating levels of the stimulatory proteins, the chloramphenicol acetyltransferase levels obtained in response to T antigen and adenovirus E1A were additive. COS-1 cells, which are derived from CV-1 cells and constitutively express simian virus 40 T antigen, do not support E2 promoter trans activation by T antigen. E1A trans activation of the E2 promoter is efficient in COS-1 cells. These results suggest that although promoter sequence requirements are similar, T antigen and E1A trans activate the E2 promoter by different mechanisms.

Simian virus 40 large-T antigen expresses a biological activity complementary to the p300-associated transforming function of the adenovirus E1A gene products

1991 ◽  
Vol 11 (4) ◽  
pp. 2116-2124
Author(s):  
P Yaciuk ◽  
M C Carter ◽  
J M Pipas ◽  
E Moran
Keyword(s):  
Biological Activity ◽  
Rat Kidney ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Binding Region ◽  
Adenovirus E1a ◽  
P300 Binding ◽  
Transforming Activity ◽  
E1a Gene

In this report we present evidence that simian virus 40 T antigen encodes a biological activity that is functionally equivalent to the transforming activity lost by deletion of the E1A p300-binding region. T-antigen constructs from which the pRb-binding region has been deleted are virtually unable to induce foci of transformed cells in a ras cooperation assay in primary baby rat kidney cells. Nevertheless, such a construct can cooperate with an E1A N-terminal deletion mutant, itself devoid of transforming activity, to induce foci in this assay. The heterologous trans-cooperating activity observed between E1A and T-antigen deletion products is as efficient as trans cooperation between mutants expressing individual E1A domains. The cooperating function can be impaired by a deletion near the N terminus of T antigen. Such a deletion impairs neither the p53-binding function nor the activity of the pRb-binding region.

scholarly journals Simian virus 40 large-T antigen expresses a biological activity complementary to the p300-associated transforming function of the adenovirus E1A gene products.

1991 ◽  
Vol 11 (4) ◽  
pp. 2116-2124 ◽  
Author(s):  
P Yaciuk ◽  
M C Carter ◽  
J M Pipas ◽  
E Moran
Keyword(s):  
Biological Activity ◽  
Rat Kidney ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Binding Region ◽  
Adenovirus E1a ◽  
P300 Binding ◽  
Transforming Activity ◽  
E1a Gene

In this report we present evidence that simian virus 40 T antigen encodes a biological activity that is functionally equivalent to the transforming activity lost by deletion of the E1A p300-binding region. T-antigen constructs from which the pRb-binding region has been deleted are virtually unable to induce foci of transformed cells in a ras cooperation assay in primary baby rat kidney cells. Nevertheless, such a construct can cooperate with an E1A N-terminal deletion mutant, itself devoid of transforming activity, to induce foci in this assay. The heterologous trans-cooperating activity observed between E1A and T-antigen deletion products is as efficient as trans cooperation between mutants expressing individual E1A domains. The cooperating function can be impaired by a deletion near the N terminus of T antigen. Such a deletion impairs neither the p53-binding function nor the activity of the pRb-binding region.

scholarly journals Stimulation of the Human Heat Shock Protein 70 Promoter in Vitro by Simian Virus 40 Large T Antigen

1989 ◽  
Vol 264 (27) ◽  
pp. 16160-16164
Author(s):  
I C Taylor ◽  
W Solomon ◽  
B M Weiner ◽  
E Paucha ◽  
M Bradley ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Large T Antigen ◽  
Human Heat Shock Protein ◽  
Stimulation Of

Maintenance of cellular proliferation by adenovirus early region 1A in fibroblasts conditionally immortalized by using simian virus 40 large T antigen requires conserved region 1

1990 ◽  
Vol 10 (12) ◽  
pp. 6664-6673
Author(s):  
T E Riley ◽  
A Follin ◽  
N C Jones ◽  
P S Jat
Keyword(s):  
Cell Line ◽  
Growth Arrest ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Growth Defect ◽  
Primary Cells ◽  
Nonpermissive Temperature ◽  
Large T Antigen ◽  
Adenovirus E1a

Various mutants of adenovirus E1A were assayed for their ability to complement the growth defect at the nonpermissive temperature for the cell line tsa14 which was isolated by immortalizing rat embryo fibroblasts with the thermolabile large T antigen of tsA58. This cell line grows indefinitely at the permissive temperature but undergoes rapid growth arrest upon shift up to the nonpermissive temperature. Since this growth arrest can be overcome by introduction of wild-type simian virus 40 large T antigen, human papillomavirus 16 E7, and adenovirus E1A, the tsa14 cells provided an excellent system for defining regions of E1A necessary for complementation of the growth defect. We demonstrate that conserved region 1 (CR1) is the region of E1A required for complementation. While CR2 of E1A has been shown to be required for the immortalization of primary cells and is also necessary for the binding of the 105-kDa retinoblastoma protein, mutations within this region did not abrogate complementation of the growth defect. However, since both CR1 and CR2 have previously been shown to be absolutely required for immortalization of primary cells by adenovirus E1A, this evidence suggests that the tsa14 system assays for the maintenance of proliferation and that this requires CR1.

scholarly journals Maintenance of cellular proliferation by adenovirus early region 1A in fibroblasts conditionally immortalized by using simian virus 40 large T antigen requires conserved region 1.

1990 ◽  
Vol 10 (12) ◽  
pp. 6664-6673 ◽  
Author(s):  
T E Riley ◽  
A Follin ◽  
N C Jones ◽  
P S Jat
Keyword(s):  
Cell Line ◽  
Growth Arrest ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Growth Defect ◽  
Primary Cells ◽  
Nonpermissive Temperature ◽  
Large T Antigen ◽  
Adenovirus E1a

Various mutants of adenovirus E1A were assayed for their ability to complement the growth defect at the nonpermissive temperature for the cell line tsa14 which was isolated by immortalizing rat embryo fibroblasts with the thermolabile large T antigen of tsA58. This cell line grows indefinitely at the permissive temperature but undergoes rapid growth arrest upon shift up to the nonpermissive temperature. Since this growth arrest can be overcome by introduction of wild-type simian virus 40 large T antigen, human papillomavirus 16 E7, and adenovirus E1A, the tsa14 cells provided an excellent system for defining regions of E1A necessary for complementation of the growth defect. We demonstrate that conserved region 1 (CR1) is the region of E1A required for complementation. While CR2 of E1A has been shown to be required for the immortalization of primary cells and is also necessary for the binding of the 105-kDa retinoblastoma protein, mutations within this region did not abrogate complementation of the growth defect. However, since both CR1 and CR2 have previously been shown to be absolutely required for immortalization of primary cells by adenovirus E1A, this evidence suggests that the tsa14 system assays for the maintenance of proliferation and that this requires CR1.

scholarly journals Domain structure of the simian virus 40 core origin of replication.

1986 ◽  
Vol 6 (5) ◽  
pp. 1663-1670 ◽  
Author(s):  
S Deb ◽  
A L DeLucia ◽  
C P Baur ◽  
A Koff ◽  
P Tegtmeyer
Keyword(s):  
Base Pair ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Dna Conformation ◽  
Sequence Specificity ◽  
Origin Of Replication ◽  
Base Pairs ◽  
Interaction Sites ◽  
Sequence Requirements

The simian virus 40 core origin of replication consists of nucleotides 5211 through 31. These 64 base pairs contain three functional domains with strict sequence requirements and two spacer regions with relaxed sequence specificity but precise positional constraints. The early domain extends for 10 contiguous base pairs between nucleotides 5211 and 5220. A 9-base pair spacer from sequences 5221 through 5229 separates the early domain from the 23-base pair central palindrome that directs the binding of T antigen. The late end of the core between nucleotides 12 and 31 also contains spacer and sequence-specific functions that are not yet completely mapped. We propose that the sequence-specific domains are interaction sites for viral and cellular proteins, determinants of DNA conformation, or both. The spacers would position these signals at required distances and rotations relative to one another.

scholarly journals Tumorigenicity of fibroblast lines expressing the adenovirus E1a, cellular p53, or normal c-myc genes.

1986 ◽  
Vol 6 (1) ◽  
pp. 7-14 ◽  
Author(s):  
A Kelekar ◽  
M D Cole
Keyword(s):  
Simian Virus 40 ◽  
Adenovirus Type ◽  
Simian Virus ◽  
Primary Cells ◽  
Adenovirus E1a ◽  
Immortalized Cells ◽  
Transforming Activity ◽  
E1a Gene

Cellular and viral oncogenes have been linked to the transformation of established cell lines in vitro, to the induction of tumors in vivo, and to the partial transformation or immortalization of primary cells. Based on the ability to cooperate with mutated ras oncogenes in the transformation of primary cells, the adenovirus E1a and cellular p53 genes have been assigned an immortalizing activity. It is demonstrated in this paper that the adenovirus type 5 E1a gene and simian virus 40 promoter-linked p53 cDNA are able to transform previously immortalized cells to a tumorigenic phenotype without a significant change in cell morphology. It is also shown that, when linked to a constitutive promoter, the normal mouse and human c-myc genes have the same transforming activity. Cells transformed by each of these oncogenes have an increased capacity to grow in the absence of growth factors and a limited anchorage-independent growth capability.

Stimulation of RNA synthesis in isolated nucleoli by preparations of simian virus 40 T antigen

Virology ◽  
1978 ◽  
Vol 88 (1) ◽  
pp. 82-91 ◽  
Author(s):  
Sandra Whelly ◽  
Toshinori Ide ◽  
Renato Baserga
Keyword(s):  
Rna Synthesis ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Stimulation Of
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