Origin melting by SV40 Large T antigen-new insights from 3D-EM-MLF3D classification method

2008 ◽  
pp. 15-16
Author(s):  
J. M. Carazo ◽  
I. Cuesta ◽  
R. Nuñez-Ramirez ◽  
S. H. Scheres
Keyword(s):  
T Antigen ◽  
Classification Method ◽  
Large T Antigen ◽  
Sv40 Large T Antigen ◽  
3D Em

scholarly journals Unwinding of chromatin by the SV40 large T antigen DNA helicase.

1995 ◽  
Vol 14 (13) ◽  
pp. 3215-3225 ◽  
Author(s):  
U. Ramsperger ◽  
H. Stahl
Keyword(s):  
Dna Helicase ◽  
T Antigen ◽  
Large T Antigen ◽  
Sv40 Large T Antigen

Retroviral transduction of human periodontal cells with a temperature-sensitive SV40 large T antigen

1999 ◽  
Vol 44 (10) ◽  
pp. 823-834 ◽  
Author(s):  
M.H. Parkar ◽  
L. Kuru ◽  
M. O’Hare ◽  
H.N. Newman ◽  
F. Hughes ◽  
...  
Keyword(s):  
T Antigen ◽  
Temperature Sensitive ◽  
Large T Antigen ◽  
Sv40 Large T Antigen ◽  
Retroviral Transduction

SV40 small t antigen enhances the transformation activity of limiting concentrations of SV40 large T antigen

Cell ◽  
1987 ◽  
Vol 48 (2) ◽  
pp. 321-330 ◽  
Author(s):  
Ilan Bikel ◽  
Ximena Montano ◽  
Mounzer E. Agha ◽  
Myles Brown ◽  
Melissa McCormack ◽  
...  
Keyword(s):  
T Antigen ◽  
Large T Antigen ◽  
Sv40 Large T Antigen ◽  
Transformation Activity ◽  
Small T Antigen ◽  
Sv40 Small T

Recombinant retroviruses encoding simian virus 40 large T antigen and polyomavirus large and middle T antigens

1986 ◽  
Vol 6 (4) ◽  
pp. 1204-1217
Author(s):  
P S Jat ◽  
C L Cepko ◽  
R C Mulligan ◽  
P A Sharp
Keyword(s):  
Cell Lines ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Vector System ◽  
Large T Antigen ◽  
T Antigens ◽  
Sv40 Large T Antigen ◽  
Polyomavirus Middle T Antigen ◽  
Middle T Antigen

We used a murine retrovirus shuttle vector system to construct recombinants capable of constitutively expressing the simian virus 40 (SV40) large T antigen and the polyomavirus large and middle T antigens as well as resistance to G418. Subsequently, these recombinants were used to generate cell lines that produced defective helper-free retroviruses carrying each of the viral oncogenes. These recombinant retroviruses were used to analyze the role of the viral genes in transformation of rat F111 cells. Expression of the polyomavirus middle T antigen alone resulted in cell lines that were highly tumorigenic, whereas expression of the polyomavirus large T resulted in cell lines that were highly tumorigenic, whereas expression of the polyomavirus large T resulted in cell lines that were unaltered by the criteria of morphology, anchorage-independent growth, and tumorigenicity. More surprisingly, SV40 large T-expressing cell lines were not tumorigenic despite the fact that they contained elevated levels of cellular p53 and had a high plating efficiency in soft agar. These results suggest that the SV40 large T antigen is not an acute transforming gene like the polyomavirus middle T antigen but is similar to the establishment genes such as myc and adenovirus EIa.

Xeroderma Pigmentosum Variant: Generation and Characterization of Fibroblastic Cell Lines Transformed with SV40 Large T Antigen

1995 ◽  
Vol 217 (1) ◽  
pp. 100-108 ◽  
Author(s):  
Sharon A. King ◽  
Sandra J. Wilson ◽  
Rosann A. Farber ◽  
William K. Kaufmann ◽  
Marila Cordeiro-Stone
Keyword(s):  
Cell Lines ◽  
Xeroderma Pigmentosum ◽  
T Antigen ◽  
Large T Antigen ◽  
Fibroblastic Cell ◽  
Sv40 Large T Antigen

Growth Properties of Neural Cell Lines Immortalized with the Tsa58 Allele of Sv40 Large T Antigen

1997 ◽  
Vol 6 (3) ◽  
pp. 231-238 ◽  
Author(s):  
M.E. Truckenmiller ◽  
Ora Dillon-Carter ◽  
Carlo Tornatore ◽  
Henrietta Kulaga ◽  
Hidetoshi Takashima ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Line ◽  
Cell Lines ◽  
T Antigen ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Large T Antigen ◽  
Wild Type ◽  
Sv40 Large T Antigen ◽  
Growth Properties

In vitro growth properties of three CNS-derived cell lines were compared under a variety of culture conditions. The M213-20 and J30a cell lines were each derived from embryonic CNS culture with the temperature-sensitive (ts) allele of SV40 large T antigen, tsA58, while the A7 cell line was immortalized using wild-type SV40 large T antigen. Cells immortalized with tsA58 SV40 large T proliferate at the permissive temperature, 33° C, while growth is expected to be suppressed at the nonpermissive temperature, 39.5°C. Both the M213-20 and J30a cell lines were capable of proliferating at 39.5°C continuously for up to 6 mo. All three cell lines showed no appreciable differences in growth rates related to temperature over a 7-day period in either serum-containing or defined serum-free media. The percentage of cells in S-phase of the cell cycle did not decrease or was elevated at 39.5°C for all three cell lines. After 3 wk at 39.5°C, the three cell lines also showed positive immunostaining using two monoclonal antibodies reacting with different epitopes of SV40 large T antigen. Double strand DNA sequence analyses of a 300 base pair (bp) fragment of the large T gene from each cell line, which included the ts locus, revealed mutations in both the J30a and M213-20 cell lines. The J30a cell line ts mutation had reverted to wild type, and two additional loci with bp substitutions with predicted amino acid changes were also found. While the ts mutation of the M213-20 cells was retained, an additional bp substitution with a predicted amino acid change was found. The A7 cell line sequence was identical to the reference wild-type sequence. These findings suggest that (a) nucleic acid sequences in the temperature-sensitive region of the tsA58 allele of SV40 large T are not necessarily stable, and (b) temperature sensitivity of cell lines immortalized with tsA58 is not necessarily retained.

scholarly journals T Antigens of Simian Virus 40: Molecular Chaperones for Viral Replication and Tumorigenesis

2002 ◽  
Vol 66 (2) ◽  
pp. 179-202 ◽  
Author(s):  
Christopher S. Sullivan ◽  
James M. Pipas
Keyword(s):  
Cell Cycle ◽  
Viral Replication ◽  
Molecular Chaperones ◽  
Tumor Antigens ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Large T Antigen ◽  
T Antigens ◽  
Sv40 Large T Antigen

SUMMARY Simian virus 40 (SV40) is a small DNA tumor virus that has been extensively characterized due to its relatively simple genetic organization and the ease with which its genome is manipulated. The large and small tumor antigens (T antigens) are the major regulatory proteins encoded by SV40. Large T antigen is responsible for both viral and cellular transcriptional regulation, virion assembly, viral DNA replication, and alteration of the cell cycle. Deciphering how a single protein can perform such numerous and diverse functions has remained elusive. Recently it was established that the SV40 T antigens, including large T antigen, are molecular chaperones, each with a functioning DnaJ domain. The molecular chaperones were originally identified as bacterial genes essential for bacteriophage growth and have since been shown to be conserved in eukaryotes, participating in an array of both viral and cellular processes. This review discusses the mechanisms of DnaJ/Hsc70 interactions and how they are used by T antigen to control viral replication and tumorigenesis. The use of the DnaJ/Hsc70 system by SV40 and other viruses suggests an important role for these molecular chaperones in the regulation of the mammalian cell cycle and sheds light on the enigmatic SV40 T antigen—a most amazing molecule.

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