Transcriptional Activation of the Human C-Myc Gene by Simian Virus 40 Large T Antigen without Binding to p53 and RB Proteins in the Transient Expression System

1997 ◽  
Vol 235 (1) ◽  
pp. 153-157 ◽  
Author(s):  
Tsutomu Shimazu ◽  
Shinako Takada ◽  
Seiichi Ishida ◽  
Yoshio Ueno ◽  
Katsuro Koike
Keyword(s):  
Transient Expression ◽  
Transcriptional Activation ◽  
Expression System ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Large T Antigen ◽  
Transient Expression System ◽  
Myc Gene

Transcriptional activation by simian virus 40 large T antigen: interactions with multiple components of the transcription complex

1993 ◽  
Vol 13 (2) ◽  
pp. 961-969
Author(s):  
M C Gruda ◽  
J M Zabolotny ◽  
J H Xiao ◽  
I Davidson ◽  
J C Alwine
Keyword(s):  
Amino Acids ◽  
Binding Site ◽  
Protein Interactions ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Large T Antigen ◽  
Sv40 Large T Antigen

Simian virus 40 (SV40) large T antigen is a potent transcriptional activator of both viral and cellular promoters. Within the SV40 late promoter, a specific upstream element necessary for T-antigen transcriptional activation is the binding site for transcription-enhancing factor 1 (TEF-1). The promoter structure necessary for T-antigen-mediated transcriptional activation appears to be simple. For example, a promoter consisting of upstream TEF-1 binding sites (or other factor-binding sites) and a downstream TATA or initiator element is efficiently activated. It has been demonstrated that transcriptional activation by T antigen does not require direct binding to the DNA; thus, the most direct effect that T antigen could have on these simple promoters would be through protein-protein interactions with either upstream-bound transcription factors, the basal transcription complex, or both. To determine whether such interactions occur, full-length T antigen or segments of it was fused to the glutathione-binding site (GST fusions) or to the Gal4 DNA-binding domain (amino acids 1 to 147) (Gal4 fusions). With the GST fusions, it was found that TEF-1 and the TATA-binding protein (TBP) bound different regions of T antigen. A GST fusion containing amino acids 5 to 172 (region T1) efficiently bound TBP. TEF-1 bound neither region T1 nor a region between amino acids 168 and 373 (region T2); however, it bound efficiently to the combined region (T5) containing amino acids 5 to 383.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Transcriptional activation by simian virus 40 large T antigen: interactions with multiple components of the transcription complex.

1993 ◽  
Vol 13 (2) ◽  
pp. 961-969 ◽  
Author(s):  
M C Gruda ◽  
J M Zabolotny ◽  
J H Xiao ◽  
I Davidson ◽  
J C Alwine
Keyword(s):  
Amino Acids ◽  
Binding Site ◽  
Protein Interactions ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Large T Antigen ◽  
Sv40 Large T Antigen

Simian virus 40 (SV40) large T antigen is a potent transcriptional activator of both viral and cellular promoters. Within the SV40 late promoter, a specific upstream element necessary for T-antigen transcriptional activation is the binding site for transcription-enhancing factor 1 (TEF-1). The promoter structure necessary for T-antigen-mediated transcriptional activation appears to be simple. For example, a promoter consisting of upstream TEF-1 binding sites (or other factor-binding sites) and a downstream TATA or initiator element is efficiently activated. It has been demonstrated that transcriptional activation by T antigen does not require direct binding to the DNA; thus, the most direct effect that T antigen could have on these simple promoters would be through protein-protein interactions with either upstream-bound transcription factors, the basal transcription complex, or both. To determine whether such interactions occur, full-length T antigen or segments of it was fused to the glutathione-binding site (GST fusions) or to the Gal4 DNA-binding domain (amino acids 1 to 147) (Gal4 fusions). With the GST fusions, it was found that TEF-1 and the TATA-binding protein (TBP) bound different regions of T antigen. A GST fusion containing amino acids 5 to 172 (region T1) efficiently bound TBP. TEF-1 bound neither region T1 nor a region between amino acids 168 and 373 (region T2); however, it bound efficiently to the combined region (T5) containing amino acids 5 to 383.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Simian Virus 40 Large T Antigen Interacts with Human TFIIB-Related Factor and Small Nuclear RNA-Activating Protein Complex for Transcriptional Activation of TATA-Containing Polymerase III Promoters

1998 ◽  
Vol 18 (3) ◽  
pp. 1331-1338 ◽  
Author(s):  
Blossom Damania ◽  
Renu Mital ◽  
James C. Alwine
Keyword(s):  
Transcriptional Activation ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Related Factor ◽  
Small Nuclear Rna ◽  
Large T Antigen ◽  
Pol Ii ◽  
Nuclear Rna ◽  
Pol Iii

ABSTRACTThe TATA-binding protein (TBP) is common to the basal transcription factors of all three RNA polymerases, being associated with polymerase-specific TBP-associated factors (TAFs). Simian virus 40 large T antigen has previously been shown to interact with the TBP-TAFII complexes, TFIID (B. Damania and J. C. Alwine, Genes Dev. 10:1369–1381, 1996), and the TBP-TAFIcomplex, SL1 (W. Zhai, J. Tuan, and L. Comai, Genes Dev. 11:1605–1617, 1997), and in both cases these interactions are critical for transcriptional activation. We show a similar mechanism for activation of the class 3 polymerase III (pol III) promoter for the U6 RNA gene. Large T antigen can activate this promoter, which contains a TATA box and an upstream proximal sequence element but cannot activate the TATA-less, intragenic VAI promoter (a class 2, pol III promoter). Mutants of large T antigen that cannot activate pol II promoters also fail to activate the U6 promoter. We provide evidence that large T antigen can interact with the TBP-containing pol III transcription factor human TFIIB-related factor (hBRF), as well as with at least two of the three TAFs in the pol III-specific small nuclear RNA-activating protein complex (SNAPc). In addition, we demonstrate that large T antigen can cofractionate and coimmunoprecipitate with the hBRF-containing complex TFIIIB derived from HeLa cells infected with a recombinant adenovirus which expresses large T antigen. Hence, similar to its function with pol I and pol II promoters, large T antigen interacts with TBP-containing, basal pol III transcription factors and appears to perform a TAF-like function.

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