T-antigen is not bound to the replication origin of the simian virus 40 late transcription complex

1990 ◽  
Vol 215 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Kenneth G. Hadlock ◽  
Leonard C. Lutter
Keyword(s):  
Replication Origin ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Late Transcription

scholarly journals Evolutionarily selected replication origins: functional aspects and structural organization.

1986 ◽  
Vol 6 (9) ◽  
pp. 3077-3085 ◽  
Author(s):  
G J Lee-Chen ◽  
M Woodworth-Gutai
Keyword(s):  
Inverted Repeat ◽  
Replication Origin ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Inverted Repeats ◽  
Regulatory Sequences ◽  
Functional Aspects ◽  
Cellular Sequence ◽  
Transfection Mixture

A selective replicative pressure occurs during the evolution of simian virus 40 variants. When the replication origin is duplicated as an inverted repeat, there is a dramatic enhancement of replication. Having regulatory sequences located between the inverted repeat of ori magnifies their enhancing effect on replication. A passage 20 variant and a passage 45 variant containing three pairs of an inverted repeat of ori replicated more efficiently than a passage 13 variant containing nine copies of ori arranged in tandem. A 69-base-pair cellular sequence inserted between inverted repeats of ori of both passage 40 and 45 variants enhanced simian virus 40 DNA replication. Differences in replication efficiencies became greater as the total number of replicating species was increased in the transfection mixture, under conditions where T antigen is limiting. In a competitive environment, sequences flanking the replication origin may be inhibitory to replication.

Evolutionarily selected replication origins: functional aspects and structural organization

1986 ◽  
Vol 6 (9) ◽  
pp. 3077-3085
Author(s):  
G J Lee-Chen ◽  
M Woodworth-Gutai
Keyword(s):  
Inverted Repeat ◽  
Replication Origin ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Inverted Repeats ◽  
Regulatory Sequences ◽  
Functional Aspects ◽  
Cellular Sequence ◽  
Transfection Mixture

A selective replicative pressure occurs during the evolution of simian virus 40 variants. When the replication origin is duplicated as an inverted repeat, there is a dramatic enhancement of replication. Having regulatory sequences located between the inverted repeat of ori magnifies their enhancing effect on replication. A passage 20 variant and a passage 45 variant containing three pairs of an inverted repeat of ori replicated more efficiently than a passage 13 variant containing nine copies of ori arranged in tandem. A 69-base-pair cellular sequence inserted between inverted repeats of ori of both passage 40 and 45 variants enhanced simian virus 40 DNA replication. Differences in replication efficiencies became greater as the total number of replicating species was increased in the transfection mixture, under conditions where T antigen is limiting. In a competitive environment, sequences flanking the replication origin may be inhibitory to replication.

scholarly journals Sequences involved in initiation of simian virus 40 late transcription in the absence of T antigen.

1986 ◽  
Vol 6 (6) ◽  
pp. 1875-1885 ◽  
Author(s):  
F Omilli ◽  
M Ernoult-Lange ◽  
J Borde ◽  
E May
Keyword(s):  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Late Promoter ◽  
Late Gene Expression ◽  
Rich Region ◽  
Enhancer Element ◽  
Late Initiation ◽  
Late Transcription

We analyzed the sequences involved in vivo in the initiation of simian virus 40 (SV40) late transcription occurring in the absence of both SV40 origin sequences and T antigen. The constituent elements of the SV40 late promoters have already been the subject of extensive studies. In vitro studies have resulted in the description of two putative domains of the late promoters. The first domain consists of an 11-base-pair (bp) sequence, 5'-GGTACCTAACC-3', located 25 nucleotides (nt) upstream of the SV40 major late initiation site (MLIS) (J. Brady, M. Radonovich, M. Vodkin, V. Natarajan, M. Thoren, G. Das, J. Janik, and N. P. Salzman, Cell 31:624-633, 1982). The second domain is located within the G-C-rich region (J. Brady, M. Radonovich, M. Thoren, G. Das, and N. P. Salzman, Mol. Cell. Biol. 4:133-141; U. Hansen and P. A. Sharp, EMBO J. 2:2293-2303). Our previous in vivo studies permitted us to define a domain of the late promoter which extends from nt 332 to nt 113 and includes the 72-bp enhancer sequences. Here, by using transfection of the appropriate chimeric plasmids into HeLa cells in conjunction with quantitative S1 nuclease analysis, we analyzed in more detail the sequences required for the control of SV40 late-gene expression occurring before the onset of viral DNA replication. We showed that the major late promoter element is in fact the 72-bp repeat enhancer element. This element was able to drive efficient late transcription in the absence of T antigen. Under our experimental conditions, removal of the G-C-rich region (21-bp repeats) entailed a significant increase in the level of late-gene expression. Moreover, translocation of this element closer to the MLIS (53 nt upstream of the MLIS) enhanced the level of transcripts initiated at natural late initiation sites. Our results suggest that the G-C-rich regions have to be positioned between the enhancer element and the initiation sites to stimulate transcription from downstream sites. Thus, the relative arrangement of the various promoter elements is a critical factor contributing to the situation in which the early promoter is stronger than late promoters before viral DNA replication.

scholarly journals Cooperative assembly of simian virus 40 T-antigen hexamers on functional halves of the replication origin.

1991 ◽  
Vol 65 (6) ◽  
pp. 2798-2806 ◽  
Author(s):  
R E Parsons ◽  
J E Stenger ◽  
S Ray ◽  
R Welker ◽  
M E Anderson ◽  
...  
Keyword(s):  
Replication Origin ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Cooperative Assembly

Sequences involved in initiation of simian virus 40 late transcription in the absence of T antigen

1986 ◽  
Vol 6 (6) ◽  
pp. 1875-1885
Author(s):  
F Omilli ◽  
M Ernoult-Lange ◽  
J Borde ◽  
E May
Keyword(s):  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Late Promoter ◽  
Late Gene Expression ◽  
Rich Region ◽  
Enhancer Element ◽  
Late Initiation ◽  
Late Transcription

We analyzed the sequences involved in vivo in the initiation of simian virus 40 (SV40) late transcription occurring in the absence of both SV40 origin sequences and T antigen. The constituent elements of the SV40 late promoters have already been the subject of extensive studies. In vitro studies have resulted in the description of two putative domains of the late promoters. The first domain consists of an 11-base-pair (bp) sequence, 5'-GGTACCTAACC-3', located 25 nucleotides (nt) upstream of the SV40 major late initiation site (MLIS) (J. Brady, M. Radonovich, M. Vodkin, V. Natarajan, M. Thoren, G. Das, J. Janik, and N. P. Salzman, Cell 31:624-633, 1982). The second domain is located within the G-C-rich region (J. Brady, M. Radonovich, M. Thoren, G. Das, and N. P. Salzman, Mol. Cell. Biol. 4:133-141; U. Hansen and P. A. Sharp, EMBO J. 2:2293-2303). Our previous in vivo studies permitted us to define a domain of the late promoter which extends from nt 332 to nt 113 and includes the 72-bp enhancer sequences. Here, by using transfection of the appropriate chimeric plasmids into HeLa cells in conjunction with quantitative S1 nuclease analysis, we analyzed in more detail the sequences required for the control of SV40 late-gene expression occurring before the onset of viral DNA replication. We showed that the major late promoter element is in fact the 72-bp repeat enhancer element. This element was able to drive efficient late transcription in the absence of T antigen. Under our experimental conditions, removal of the G-C-rich region (21-bp repeats) entailed a significant increase in the level of late-gene expression. Moreover, translocation of this element closer to the MLIS (53 nt upstream of the MLIS) enhanced the level of transcripts initiated at natural late initiation sites. Our results suggest that the G-C-rich regions have to be positioned between the enhancer element and the initiation sites to stimulate transcription from downstream sites. Thus, the relative arrangement of the various promoter elements is a critical factor contributing to the situation in which the early promoter is stronger than late promoters before viral DNA replication.

scholarly journals The simian virus 40 T antigen double hexamer assembles around the DNA at the replication origin.

1992 ◽  
Vol 267 (20) ◽  
pp. 14129-14137
Author(s):  
F.B. Dean ◽  
J.A. Borowiec ◽  
T Eki ◽  
J Hurwitz
Keyword(s):  
Replication Origin ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen
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