Studies of Simian Virus 40 DNA VII. A Cleavage Map of the SV40 Genome

1989 ◽  
pp. 515-530
Author(s):  
KATHLEEN J. DANNA ◽  
GEORGE H. SACK ◽  
DANIEL NATHANS
Keyword(s):  
Simian Virus 40 ◽  
Simian Virus ◽  
Sv40 Genome

Topological requirements for homologous recombination among DNA molecules transfected into mammalian cells

1985 ◽  
Vol 5 (8) ◽  
pp. 2080-2089
Author(s):  
C T Wake ◽  
F Vernaleone ◽  
J H Wilson
Keyword(s):  
Homologous Recombination ◽  
Mammalian Cells ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Animal Cells ◽  
Linear Molecules ◽  
Sv40 Genome ◽  
Foreign Dna ◽  
The Individual ◽  
Sv40 Dna

Cultured animal cells rearrange foreign DNA very efficiently by homologous recombination. The individual steps that constitute the mechanism(s) of homologous recombination in transfected DNA are as yet undefined. In this study, we examined the topological requirements by using the genome of simian virus 40 (SV40) as a probe. By assaying homologous recombination between defective SV40 genomes after transfection into CV1 monkey cells, we showed that linear molecules are preferred substrates for homologous exchanges, exchanges are distributed around the SV40 genome, and the frequency of exchange is not diminished significantly by the presence of short stretches of non-SV40 DNA at the ends. These observations are considered in relation to current models of homologous recombination in mammalian cells, and a new model is proposed. The function of somatic cell recombination is discussed.

scholarly journals Topological requirements for homologous recombination among DNA molecules transfected into mammalian cells.

1985 ◽  
Vol 5 (8) ◽  
pp. 2080-2089 ◽  
Author(s):  
C T Wake ◽  
F Vernaleone ◽  
J H Wilson
Keyword(s):  
Homologous Recombination ◽  
Mammalian Cells ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Animal Cells ◽  
Linear Molecules ◽  
Sv40 Genome ◽  
Foreign Dna ◽  
The Individual ◽  
Sv40 Dna

Cultured animal cells rearrange foreign DNA very efficiently by homologous recombination. The individual steps that constitute the mechanism(s) of homologous recombination in transfected DNA are as yet undefined. In this study, we examined the topological requirements by using the genome of simian virus 40 (SV40) as a probe. By assaying homologous recombination between defective SV40 genomes after transfection into CV1 monkey cells, we showed that linear molecules are preferred substrates for homologous exchanges, exchanges are distributed around the SV40 genome, and the frequency of exchange is not diminished significantly by the presence of short stretches of non-SV40 DNA at the ends. These observations are considered in relation to current models of homologous recombination in mammalian cells, and a new model is proposed. The function of somatic cell recombination is discussed.

Simian virus 40 minichromosomes contain torsionally strained DNA molecules

1985 ◽  
Vol 5 (11) ◽  
pp. 3048-3057
Author(s):  
J Barsoum ◽  
P Berg
Keyword(s):  
Topoisomerase I ◽  
Simian Virus 40 ◽  
Staphylococcal Nuclease ◽  
Simian Virus ◽  
Infected Cells ◽  
Complete Digestion ◽  
Sv40 Genome ◽  
Negative Supercoiling ◽  
Sv40 Dna ◽  
Nuclease Sensitivity

Sundin and Varshavsky (J. Mol. Biol. 132:535-546, 1979) found that nearly two-thirds of simian virus 40 (SV40) minichromosomes obtained from nuclei of SV40-infected cells become singly nicked or cleaved across both strands after digestion with staphylococcal nuclease at 0 degrees C. The same treatment of SV40 DNA causes complete digestion rather than the limited cleavages produced in minichromosomal DNA. We have explored this novel behavior of the minichromosome and found that the nuclease sensitivity is dependent upon the topology of the DNA. Thus, if minichromosomes are pretreated with wheat germ DNA topoisomerase I, the minichromosomal DNA is completely resistant to subsequent digestion with staphylococcal nuclease at 0 degrees C. If the minichromosome-associated topoisomerase is removed, virtually all of the minichromosomes are cleaved to nicked or linear structures by the nuclease treatment. The cleavage sites are nonrandomly located; instead they occur at discrete loci throughout the SV40 genome. SV40 minichromosomal DNA is also cleaved to nicked circles and full-length linear fragments after treatment with the single strand-specific endonuclease S1; this cleavage is also inhibited by pretreatment with topoisomerase I. Thus, it may be that the nuclease sensitivity of minichromosomes is due to the transient or permanent unwinding of discrete regions of their DNA. Direct comparisons of the extent of negative supercoiling of native and topoisomerase-treated SV40 minichromosomes revealed that approximately two superhelical turns were removed by the topoisomerase treatment. The loss of these extra negative supercoils from the DNA probably accounts for the resistance of the topoisomerase-treated minichromosomes to the staphylococcal and S1 nucleases. These findings suggest that the DNA in SV40 intranuclear minichromosomes is torsionally strained. The functional significance of this finding is discussed.

Structure of two adenovirus-simian virus 40 hybrids which contain the entire SV40 genome

1974 ◽  
Vol 89 (1) ◽  
pp. 113-126 ◽  
Author(s):  
Thomas J. Kelly ◽  
Andrew M. Lewis ◽  
Arthur S. Levine ◽  
Stuart Siegel
Keyword(s):  
Simian Virus 40 ◽  
Simian Virus ◽  
Sv40 Genome

scholarly journals Activation of the simian virus 40 (SV40) genome abrogates sensitivity to AVP in a rabbit collecting tubule cell line by repressing membrane expression of AVP receptors.

1991 ◽  
Vol 113 (4) ◽  
pp. 951-962 ◽  
Author(s):  
D Prié ◽  
P M Ronco ◽  
B Baudouin ◽  
M Géniteau-Legendre ◽  
M Antoine ◽  
...  
Keyword(s):  
Cell Line ◽  
Simian Virus 40 ◽  
Temperature Shift ◽  
Simian Virus ◽  
Temperature Sensitive ◽  
Membrane Expression ◽  
Cell Content ◽  
Collecting Tubule ◽  
Sv40 Genome ◽  
Transformed Cell Lines

To analyze the role of SV40 genome in the phenotypic alterations previously observed in SV40-transformed cell lines, we infected rabbit renal cortical cells with a temperature-sensitive SV40 mutant strain (tsA58) and compared the cell phenotypes at temperatures permissive (33 degrees C) and restrictive (39.5 degrees C) for SV40 genome expression. At both temperatures, the resulting cell line (RC.SVtsA58) expresses cytokeratin and uvomorulin, but epithelial differentiation is more elaborate at 39.5 degrees C as shown by the formation of a well-organized cuboidal monolayer with numerous tight junctions and desmosomes. Functional characteristics are also markedly influenced by the culture temperature: cells grown at 33 degrees C respond only to isoproterenol (ISO, 10(-6) M) by a sevenfold increase in cAMP cell content above basal values; in contrast, when transferred to 39.5 degrees C, they exhibit increased sensitivity to ISO (ISO/basal: 19.1) and a dramatic response to 10(-7) M dDarginine vasopressin (dDAVP/basal: 18.2, apparent Ka: 5 X 10(-9) M) which peaks 48 h after the temperature shift. The latter is associated with membrane expression of V2-type AVP receptors (approximately 50 fmol/10(6) cells) which are undetectable when SV40 genome is activated (33 degrees C). Clonal analysis, additivity studies, and desensitization experiments argue for the presence of a single cell type responsive to both AVP and ISO. The characteristics of the RC. SVtsA58 cell line at 39.5 degrees C (effector-stimulated cAMP profile, lack of expression of brush-border hydrolases and Tamm-Horsfall protein) suggest that it originates from the cortical collecting tubule, and probably from principal cells.

scholarly journals CONCORDANT SEGREGATION OF THE EXPRESSION OF SV40 T ANTIGEN AND HUMAN CHROMOSOME 7 IN MOUSE-HUMAN HYBRID SUBCLONES

1974 ◽  
Vol 139 (5) ◽  
pp. 1350-1353 ◽  
Author(s):  
Carlo M. Croce ◽  
Hilary Koprowski
Keyword(s):  
Human Chromosome ◽  
Thymidine Kinase ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Chromosome 7 ◽  
Sv40 T Antigen ◽  
Mouse Cells ◽  
Sv40 Genome ◽  
Human Chromosome 7

Subcloning of Simian virus 40 (SV40) T antigen-positive mouse-human hybrids, derived from the fusion of mouse cells deficient in thymidine kinase with SV40-transformed Lesch Nyhan fibroblasts, resulted in their segregation into T antigen-positive and negative subclones. Positive correlation between the presence of human chromosome 7 and the expression of SV40 T antigen was established in the subclones examined. These results negate the possibility of a transfer of the SV40 genome to a mouse chromosome.

scholarly journals Influence of the Viral Regulatory Region on Tumor Induction by Simian Virus 40 in Hamsters

2007 ◽  
Vol 82 (2) ◽  
pp. 871-879 ◽  
Author(s):  
Vojtech Sroller ◽  
Regis A. Vilchez ◽  
A. Renee Stewart ◽  
Connie Wong ◽  
Janet S. Butel
Keyword(s):  
Regulatory Region ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Biological Properties ◽  
Genomic Region ◽  
T Antigen ◽  
Minor Role ◽  
Sv40 Genome

ABSTRACT Most of the simian virus 40 (SV40) genome is conserved among isolates, but the noncoding regulatory region and the genomic region encoding the large T-antigen C terminus (T-ag-C) may exhibit considerable variation. We demonstrate here that SV40 isolates differ in their oncogenic potentials in Syrian golden hamsters. Experimental animals were inoculated intraperitoneally with 107 PFU of parental or recombinant SV40 viruses and were observed for 12 months to identify genetic determinants of oncogenicity. The viral regulatory region was found to exert a statistically significant influence on tumor incidence, whereas the T-ag-C played a minor role. Viruses with a single enhancer (1E) were more oncogenic than those with a two-enhancer (2E) structure. Rearrangements in the 1E viral regulatory region were detected in 4 of 60 (6.7%) tumors. Viral loads in tumors varied, with a median of 5.4 SV40 genome copies per cell. Infectious SV40 was rescued from 15 of 37 (40%) cell lines established from tumors. Most hamsters with tumors and many without tumors produced antibodies to T antigen. All viruses displayed similar transforming frequencies in vitro, suggesting that differences in oncogenic potential in vivo were due to host responses to viral infection. This study shows that SV40 strains differ in their biological properties, suggests that SV40 replicates to some level in hamsters, and indicates that the outcome of an SV40 infection may depend on the viral strain present.

scholarly journals INFECTION AND TRANSFORMATION OF MOUSE PERITONEAL MACROPHAGES BY SIMIAN VIRUS 40

1971 ◽  
Vol 134 (2) ◽  
pp. 335-350 ◽  
Author(s):  
J. Mauel ◽  
V. Defendi
Keyword(s):  
Conditioned Medium ◽  
Simian Virus 40 ◽  
Peritoneal Macrophages ◽  
Simian Virus ◽  
T Antigen ◽  
Antigenic Determinants ◽  
Functional Differences ◽  
Sv40 Genome ◽  
Mouse Peritoneal Macrophages

The stimulation of DNA synthesis in mouse (C57BL) macrophages explanted in vitro was demonstrated after treatment with conditioned medium or infection with SV40. In the latter case, induction of SV40 T antigen was detected before TdR-3H incorporation. Even though all macrophages were infected (T antigen-positive), they exhibited considerable pleomorphism, accompanied by functional differences. Permanent lines of SV40-transformed macrophages were eventually established, and one clone was isolated which replicates indefinitely and has many properties of primary macrophages: high acid phosphatase and phagocytic activity, lysozyme production, and specific antigenic determinants. These cells differ from normal macrophages in that they contain the SV40 genome, can be trypsinized, and do not require conditioned medium for continued replication.

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