scholarly journals Characterization of a surrogate TATA box promoter that regulates in vitro transcription of the simian virus 40 major late gene.

1985 ◽  
Vol 5 (3) ◽  
pp. 591-594 ◽  
Author(s):  
A Nandi ◽  
G Das ◽  
N P Salzman
Keyword(s):  
Simian Virus 40 ◽  
In Vitro Transcription ◽  
Simian Virus ◽  
Tata Box ◽  
Wild Type Virus ◽  
Base Substitution ◽  
Nucleotide Position ◽  
Start Site ◽  
Additional Base

The presence of a surrogate TATA box sequence located ca. 30 nucleotides upstream of the major late RNA start site at nucleotide position (np) 325 (Brady et al., Cell 31:625-633, 1982) has been confirmed, and its structural specificity has been determined by the generation of additional base substitution mutations at the KpnI restriction site (np 294) in cloned simian virus 40 DNA. Two mutants generated new RNA initiation sites upstream of the np 325 start site and continued to utilize the authentic start site, but with decreased efficiency. The replacement of either one or both cytosines by thymines at np 298 and np 299 specifically enhanced in vitro transcription from the np 325 start site by 430 and 800%, respectively. This enhancement was due to conversion of the simian virus 40 late promoter present in the wild-type virus to a sequence that is similar to the TATA box present in the simian virus 40 early promoter.

Characterization of a surrogate TATA box promoter that regulates in vitro transcription of the simian virus 40 major late gene

1985 ◽  
Vol 5 (3) ◽  
pp. 591-594
Author(s):  
A Nandi ◽  
G Das ◽  
N P Salzman
Keyword(s):  
Simian Virus 40 ◽  
In Vitro Transcription ◽  
Simian Virus ◽  
Tata Box ◽  
Wild Type Virus ◽  
Base Substitution ◽  
Nucleotide Position ◽  
Start Site ◽  
Additional Base

The presence of a surrogate TATA box sequence located ca. 30 nucleotides upstream of the major late RNA start site at nucleotide position (np) 325 (Brady et al., Cell 31:625-633, 1982) has been confirmed, and its structural specificity has been determined by the generation of additional base substitution mutations at the KpnI restriction site (np 294) in cloned simian virus 40 DNA. Two mutants generated new RNA initiation sites upstream of the np 325 start site and continued to utilize the authentic start site, but with decreased efficiency. The replacement of either one or both cytosines by thymines at np 298 and np 299 specifically enhanced in vitro transcription from the np 325 start site by 430 and 800%, respectively. This enhancement was due to conversion of the simian virus 40 late promoter present in the wild-type virus to a sequence that is similar to the TATA box present in the simian virus 40 early promoter.

Simian virus 40 major late promoter: an upstream DNA sequence required for efficient in vitro transcription

1984 ◽  
Vol 4 (1) ◽  
pp. 133-141
Author(s):  
J Brady ◽  
M Radonovich ◽  
M Thoren ◽  
G Das ◽  
N P Salzman
Keyword(s):  
Dna Sequence ◽  
Dna Sequences ◽  
Simian Virus 40 ◽  
Promoter Sequence ◽  
In Vitro Transcription ◽  
Simian Virus ◽  
Upstream Promoter ◽  
Upstream Promoter Sequence

We have previously identified an 11-base DNA sequence, 5'-G-G-T-A-C-C-T-A-A-C-C-3' (simian virus 40 [SV40] map position 294 to 304), which is important in the control of SV40 late RNA expression in vitro and in vivo (Brady et al., Cell 31:625-633, 1982). We report here the identification of another domain of the SV40 late promoter. A series of mutants with deletions extending from SV40 map position 0 to 300 was prepared by nuclease BAL 31 treatment. The cloned templates were then analyzed for efficiency and accuracy of late SV40 RNA expression in the Manley in vitro transcription system. Our studies showed that, in addition to the promoter domain near map position 300, there are essential DNA sequences between nucleotide positions 74 and 95 that are required for efficient expression of late SV40 RNA. Included in this SV40 DNA sequence were two of the six GGGCGG SV40 repeat sequences and an 11-nucleotide segment which showed strong homology with the upstream sequences required for the efficient in vitro and in vivo expression of the histone H2A gene. This upstream promoter sequence supported transcription with the same efficiency even when it was moved 72 nucleotides closer to the major late cap site. In vitro promoter competition analysis demonstrated that the upstream promoter sequence, independent of the 294 to 304 promoter element, is capable of binding polymerase-transcription factors required for SV40 late gene transcription. Finally, we show that DNA sequences which control the specificity of RNA initiation at nucleotide 325 lie downstream of map position 294.

scholarly journals Attenuation of late simian virus 40 mRNA synthesis is enhanced by the agnoprotein and is temporally regulated in isolated nuclear systems.

1985 ◽  
Vol 5 (6) ◽  
pp. 1327-1334 ◽  
Author(s):  
N Hay ◽  
Y Aloni
Keyword(s):  
Gel Electrophoresis ◽  
Blot Hybridization ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Wild Type Virus ◽  
Insertion Mutant ◽  
Dot Blot ◽  
Nuclear Systems

Studies were performed to verify the physiological significance of attenuation in the life cycle of simian virus 40 and the role of agnoprotein in this process. For these purposes, nuclei were isolated at various times after infection and incubated in vitro in the presence of [alpha-32P]UTP under the standard conditions which lead to attenuation. Attenuation was evident by the production of a 94-nucleotide attenuator RNA, revealed by gel electrophoresis. In parallel, the synthesis of agnoprotein was studied at various times after infection by labeling the cells for 3 h with [14C]arginine, lysing them, and analyzing the labeled proteins by gel electrophoresis. Both attenuation and the synthesis of agnoprotein were predominant towards the end of the infectious cycle. At earlier times, there was almost no attenuation and no synthesis of agnoprotein. Moreover, there was almost no attenuation even at the latest times after infection in nuclei isolated from cells infected with simian virus 40 deletion mutants that do not synthesize agnoprotein. Finally, analysis by dot blot hybridization showed higher amounts of cytoplasmic viral RNA in cells infected with an agnoprotein gene insertion mutant, delta 79, that does not produce agnoprotein, compared with cells infected with wild-type virus. The present studies indicate that attenuation is temporally regulated and suggest that agnoprotein enhances attenuation in isolated nuclei and that may also enhance it in vivo.

Induction of specific transcription by RNA polymerase III in transformed cells

1986 ◽  
Vol 6 (9) ◽  
pp. 3068-3076
Author(s):  
M F Carey ◽  
K Singh ◽  
M Botchan ◽  
N R Cozzarelli
Keyword(s):  
Rna Polymerase ◽  
Gene Family ◽  
Rna Polymerase Iii ◽  
Simian Virus 40 ◽  
In Vitro Transcription ◽  
Simian Virus ◽  
Intrinsic Signals ◽  
Polymerase Iii ◽  
Pol Iii

RNA polymerase III (pol III) transcripts of the highly repeated mouse B2 gene family are increased in many oncogenically transformed murine cell lines. In cells transformed by simian virus 40, the small, cytoplasmic B2 RNAs are present at 20-fold-higher levels than in normal cells (M. R. D. Scott, K. Westphal, and P. W. J. Rigby, Cell 34:557-567, 1983; K. Singh, M. Carey, S. Saragosti, and M. Botchan, Nature [London] 314:553-556). We found that transcripts of the highly repeated B1 gene family are also increased 20-fold upon simian virus 40 transformation and showed that these RNAs result from pol III transcription. In contrast, transcripts from less highly repeated pol III templates such as the 5S, 7SL, 7SK, 4.5SI, tRNAMet, and tRNAPro genes are unaffected. The expression of the B2 RNAs in isolated nuclei shows that the augmentation is due mainly to an increased rate of transcription by pol III. There is thus specific transformation-inducible pol III transcription. We developed an in vitro transcription assay which utilizes genomic DNA as a template to study the transcription of all members of a repetitive gene family in their native context. This assay reproduces the low cytoplasmic levels of B1 compared with B2 RNAs suggesting that this ratio is dictated by intrinsic signals in the DNA.

Fidelity of DNA synthesis in a mammalian in vitro replication system

1988 ◽  
Vol 8 (8) ◽  
pp. 3267-3271
Author(s):  
J Hauser ◽  
A S Levine ◽  
K Dixon
Keyword(s):  
Dna Replication ◽  
Shuttle Vector ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Base Substitution ◽  
Replication System ◽  
In Vitro Replication ◽  
Mutation Assay

We have used the simian virus 40 (SV40)-based shuttle vector pZ189 in a forward-mutation assay to determine the fidelity of DNA replication in the in vitro DNA replication system developed by J.J. Li and T.J. Kelly (Proc. Natl. Acad. Sci. USA 81:6973-6977, 1984). We find that very few base substitution errors (approximately 1/180,000 bases incorporated) are made during in vitro replication of the pZ189 vector in a system derived from CV-1 monkey cells. This replication is completely dependent on added SV40 T antigen and presumably reflects synthesis that is initiated at the SV40 replication origin. The observed level of fidelity is far greater than that reported for in vitro replication of DNA by conventionally purified eucaryotic DNA polymerases alpha and beta. Thus, there must be additional cellular factors in the crude in vitro system that serve to enhance the fidelity of DNA replication.

scholarly journals Simian virus 40 major late promoter: a novel tripartite structure that includes intragenic sequences.

1988 ◽  
Vol 8 (5) ◽  
pp. 2021-2033 ◽  
Author(s):  
D E Ayer ◽  
W S Dynan
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Point Mutations ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Transcription Unit ◽  
Tata Box ◽  
Base Pairs

Unlike most genes transcribed by RNA polymerase II, the simian virus 40 late transcription unit does not have a TATA box. To determine what sequences are required for initiation at the major late mRNA cap site of simian virus 40, clustered point mutations were constructed and tested for transcriptional activity in vitro and in vivo. Three promoter elements were defined. The first is centered 31 base pairs upstream of the cap site in a position normally reserved for a TATA box. The second is at the cap site. The third occupies a novel position centered 28 base pairs downstream of the cap site within a protein-coding sequence. The ability of RNA polymerase II to recognize this promoter suggests that there is greater variation in promoter architecture than had been believed previously.

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