Enzyme induction in SV40-infected green monkey kidney cultures

Kit, Saul; Dubbs, D. R.; Frearson, Peter M.; Melnick, Joseph L.

doi:10.1016/0042-6822(66)90197-8

Cited by 106 publications

(83 citation statements)

References 43 publications

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“…The SV40 A gene product might stimulate the de novo synthesis of the 54K protein, as it apparently does for several celllar enzymatic activities (8,19) and the cellular ribosomal and transfer ribonucleic acid (RNA) genes (7,25). Alternatively, the SV40 T-antigen might act at a post-translational step to stabilize a rapid turnover of the 54K protein in infected or transformed cells.…”

mentioning

confidence: 99%

Post-translational regulation of the 54K cellular tumor antigen in normal and transformed cells.

Oren¹,

Maltzman²,

Levine³

1981

Mol. Cell. Biol.

484

284

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The 54K cellular tumor antigen has been translated in vitro, using messenger ribonucleic acids from simian virus 40 (SV40)-transformed cells or 3T3 cells. The in vitro 54K product could be immmunoprecipitated with SV40 tumor serum and had a peptide map that was similar, but not identical, to the in vivo product. The levels of this 54K protein in SV3T3 cells were significantly higher than those detected in 3T3 cells (D. I. H. Linzer, W. Maltzmnan, and A. J. Levine, Virology 98:308-318, 1979). In spite of this, the levels of translatable 54K messenger ribonucleic acid from 3T3 and SV3T3 cells were roughly equivalent or often greater in 3T3 cells. Pulse-chase experiments with the 54K protein from 3T3 or SV3T3 cells demonstrated that this protein, once synthesized, was rapidly degraded in 3T3 cells but was extremely stable in SV3T3 cells. Similarily, in an SV40 tsA-transformed cell line, temperature sensitive for the SV40 T-antigen, the 54K protein was rapidly turned over at the nonpermissive temperature and stable at the permissive temperature, whereas the levels of translatable 54K messenger ribonucleic acid at each temperature were roughly equal. These results demonstrate a post-translational regulation of the 54K cellular tumor antigen and suggest that this control is mediated by the SV40 large T-antigen. Animals bearing simian virus 40 (SV40)-induced tumors produce antibody to two viruscoded proteins, the large T-antigen (24) and the small t-antigen (3,20), and a cellular protein of about 54,000 molecular weight (54K) (2,9,10,12,16,23). The 54K protein has been detected in mouse 3T3 cells at about 2% the levels expressed in SV40-transformed 3T3 cells (13). SV40 infection of 3T3 cells results in a 20-to 30-fold increase in the levels of detectable 54K protein in these cells (12, 13). The SV40 A gene product, or large T-antigen, is required for this stimulation in the level of the cellular 54K protein in both virus-infected and -transformed mouse cells (13). Similar or identical proteins of 53,000 to 55,000 molecular weight have been detected in murine chemically transformed cell lines (4), embryonal carcinoma cell lines (12), spontaneously transformed cells (4; W. Maltzman, M. Oren, and A. J. Levine, Virology, in press), and lymphocytes from irradiation-induced leukemia (4). Both immunologically and chemically related 54K proteins have been detected in SV40-transformed rat, hamster, monkey, and human cell lines (6,22). Thus, the expression of high levels of the 54K protein appears to be correlated with btansformation (although not every transformed cell line expresses detectable levels of this protein), and the 54K protein appears to have been conserved, in part, over evolutionary time scales.The mechanism by which the SV40 T-antigen increases the levels of the 54K cellular protein in virus-infected or -transformed cells is at present unclear. The SV40 A gene product might stimulate the de novo synthesis of the 54K protein, as it apparently does for several celllar enzymatic activities (8,19) and the cellular ...

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mentioning

confidence: 99%

Post-translational regulation of the 54K cellular tumor antigen in normal and transformed cells.

Oren¹,

Maltzman²,

Levine³

1981

Mol. Cell. Biol.

484

284

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“…This induction is not absolutely dependent upon DNA synthesis (13), but does require both RNA and protein syntheses, suggesting that induction may be at the level of transcription. TK can also be induced by infection of resting cells with papovaviruses such as simian virus 40 (SV40) and polyoma (16,17), and the viral genes required for this induction are the large T antigens (30). Whether viral induction occurs by the same or a different mechanism(s) as serum induction is a question that remains to be answered.…”

mentioning

confidence: 99%

Induction of cellular thymidine kinase occurs at the mRNA level.

Stuart¹,

Ito²,

Stewart³

et al. 1985

Mol. Cell. Biol.

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The thymidine kinase (TK) gene has been isolated from human genomic DNA. The gene was passaged twice by transfection of LTK- Thymidine kinase (TK) is an enzyme in the pyrimidine salvage pathway that catalyzes the phosphorylation of thymidine to dTMP. Many mammalian cells, including human HeLa cells, contain both cytoplasmic and mitochondrial forms of the enzyme (3), but the cytoplasmic form alone concerns us here. The regulation of the synthesis of TK is interesting because it is typical of that seen for many enzymes involved in DNA metabolism. TK activity is closely linked to the growth state of the cell, being present in rapidly growing but not in resting cells (13). In synchronized populations of cells, the activity is low in resting or Gl phase cells, but increases dramatically 10 to 20 h after the cells are released from arrest by serum stimulation, in parallel with the onset of DNA synthesis and entry into S phase. This induction is not absolutely dependent upon DNA synthesis (13), but does require both RNA and protein syntheses, suggesting that induction may be at the level of transcription. TK can also be induced by infection of resting cells with papovaviruses such as simian virus 40 (SV40) and polyoma (16,17), and the viral genes required for this induction are the large T antigens (30). Whether viral induction occurs by the same or a different mechanism(s) as serum induction is a question that remains to be answered.The TK gene provides a useful model system for carrying out a molecular analysis of genes that are cell cycle regulated and induced by viral infection. First, TK shows a great increase in activity (10-to 20-fold) after both serum and viral induction. Moreover, TK enzyme assays are both sensitive and easily performed. We can genetically select both for (hypoxanthine-aminopterin-thymidine media) and against (bromodeoxyuridine media) the TK+ phenotype, and many TK-cell lines exist. It has been shown that LTK-cells transfected to a TK+ phenotype with heterologous (human, rat, or hamster) chromosomal DNA containing a functional TK gene exhibit normal cell cycle regulation of the gene (31). Recent experiments with a cloned human gene (5) that the sequences required for cell cycle regulation are closely linked to the gene and function after transfection into TK-cells. Thus, this system should offer the chance to dissect the sequences involved in cell cycle-specific gene regulation.The mechanisms by which the expression of cell cycle-dependent genes is controlled, and by which the papovaviruses override these controls, remain obscure, although many of the initial observations were made more than 15 years ago. To a large extent this is because molecular probes for these genes and their transcripts have not been available. In this paper we report the isolation of both the human chromosomal TK locus and a functional human TK cDNA clone. Isolation of the chromosomal locus has previously been reported by several investigators (5,19,22), and our mapping is essentially in agreement with their data. In a...

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“…The cells were disrupted by freezing and thawing and by sonic oscillation at ~o kc for 3 min at 4 °C. Temperature-resistant SV4o was assayed on CV-I monolayers at 36"5 °C and total (temperature-resistant + temperature-sensitive) SV4o at 33"5 °C (Kit et al 1966).…”

Section: Methodsmentioning

confidence: 99%

“…Replication of spontaneously produced SV4o IO9 DNA synthesis (Kit et al 1966). Reversal of the ara-C block would permit synchronization of the replication of the ts SV4o DNA and the newly excised endogenous SV4o DNA.…”

Section: Effect Of Treatment With Ara-c On Induction Of Sv4o In Wi38 mentioning

confidence: 99%

Replication of the Resident Non-Defective SV40 in Transformed Human Cells Superinfected with DNA from a Temperature-sensitive SV40 Mutant

Dubbs

Kit

1973

Journal of General Virology

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SUMMARYParental and clonal lines of SV4o-transformed human embryonic lung (WI38 Va13A) cells spontaneously produce infectious virus which is temperature-resistant (tr), i.e. replicates in monkey kidney cells at either 38"7 °C or 33"5 °C. Superinfection of WI38 Va~3A cells lines with DNA from a temperature-sensitive (ts) SV4o mutant at the permissive temperature (33"5 °C) did not enhance the yield of tr SV4o as would be expected if the superinfecting ts SV4o DNA neutralized an SV4o-specific repressor, or if the ts SV4o DNA supplied a virus-specific excision function and/or post-excision functions for the maturation of the resident tr SV4o. The failure of superinfecting ts SV4o to enhance replication of the resident tr SV4o of WI38 VaI 3A cells is not due merely to a competitive advantage of the replicating superinfecting SV4 o over the endogenous SV4o. Experiments were carried out with ~-fl-o-arabinofuranosylcytosine (ara-C) treated and ts SV4o DNA-infected WI38 Va 13A cells to permit expression of early ts SV4o functions and to synchronize replication of ts SV4 o DNA and the newly excised endogenous SV4o DNA. Ara-C treatment did not enhance formation of the endogenous tr virus. In further competition experiments, CV-I cells were preinfected with ts SV4o particles and superinfected 6 to 24 h later with tr SV4o DNA recovered from SV4o spontaneously produced by WI38 VaI 3A cells. Even when the interval between the first and second infection was 24 b, very significant amounts of tr SV4o synthesis occurred and 28 ~ of doubly infected cells still produced temperature-resistant infectious centres. The experiments suggest that rescue of the resident SV4o is determined primarily by cellular rather than superinfecting SV4o gene functions.

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Enzyme induction in SV40-infected green monkey kidney cultures

Cited by 106 publications

References 43 publications

Post-translational regulation of the 54K cellular tumor antigen in normal and transformed cells.

Post-translational regulation of the 54K cellular tumor antigen in normal and transformed cells.

Induction of cellular thymidine kinase occurs at the mRNA level.

Replication of the Resident Non-Defective SV40 in Transformed Human Cells Superinfected with DNA from a Temperature-sensitive SV40 Mutant

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