1887

Abstract

Amplification of bovine papillomavirus type 1 (BPV-1) DNA in growth-arrested mouse cell cultures appears to mimic the process of induction of vegetative BPV-1 DNA synthesis in cells of the stratum spinosum in productively infected bovine warts. In both cases, cells permissive for viral DNA amplification express large amounts of viral E2 protein which accumulates within the cell nucleus. Whereas in latently infected virus-transformed cells truncated transcriptional repressor forms of E2 predominate, our previous studies have demonstrated that the full-length E2 transcriptional trans-activator protein is preferentially expressed during the period of maximal BPV-1 DNA amplification in growth-arrested cell cultures. To investigate the role of the full-length E2 gene in the induction of viral DNA amplification in this experimental viral replication system we have used a mutant BPV-1 genome (BPVE2-1) containing an E2 gene which is temperature-sensitive (ts) for transcriptional trans-activation. This mutant genome has also been shown to be ts for stable viral plasmid DNA replication and for the induction of cell transformation. We show here that viral DNA amplification was not severely impaired when BPVE2-1-transformed cells were tested at the restrictive temperature, indicating that the transcriptional trans-activating function of E2 was not essential for viral DNA amplification in division-arrested cells and, moreover, that the trans-activation and replication functions of E2 were separable. Consistent with this hypothesis, amplification of the BPVE2-1 genome at the restrictive temperature was still associated with the accumulation of large amounts of nuclear E2 antigen, showing that the mutation did not disrupt nuclear transport or render the E2 protein highly unstable. Furthermore, C127 cells harbouring ts E2 and full-length E1 expression constructs supported transient plasmid replication of a BPV origin vector at the restrictive temperature. These observations imply that E2 functions primarily as a viral replication factor in the vegetative phase of BPV-1 DNA replication, and suggest a fundamental difference in the genetic regulation of stable BPV-1 plasmid DNA replication in mitotic cells and viral DNA amplification in postmitotic cells.

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1992-10-01
2021-10-24
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References

  1. Androphy E. J., Lowy D. R., Schiller J. T. 1987; Bovine papillomavirus E2 tranx-activating gene product binds to specific sites in papillomavirus DNA. Nature, London 325:70–73
    [Google Scholar]
  2. Berg L., Lusky M., Stenlund A., Botchan M. R. 1986; Repression of bovine papillomavirus replication is mediated by a virally encoded trans- acting factor. Cell 46:753–762
    [Google Scholar]
  3. Botchan M. R., Berg L., Reynolds J., Lusky M. 1986; The bovine papillomavirus replicon. In Papillomaviruses pp. 53–67 Edited by Evered D., Clark S. New York: John Wiley & Sons;
    [Google Scholar]
  4. Burnett S., Moreno-Lopez J., Pettersson U. 1988; A novel spontaneous mutation of the bovine papillomavirus-1 genome. Plasmid 20:61–74
    [Google Scholar]
  5. Burnett S., Kiessling U., Pettersson U. 1989; Loss of bovine papillomavirus DNA replication control in growth-arrested transformed cells. Journal of Virology 63:2215–2225
    [Google Scholar]
  6. Burnett S., Strom A. C., Jareborg N., Alderborn A., Dillner J., Moreno-Lopez J., Pettersson U., Kiessling U. 1990; Induction of bovine papillomavirus E2 gene expression and early region transcription by cell growth arrest: correlation with viral DNA amplification and evidence for differential promoter induction. Journal of Virology 64:5529–5541
    [Google Scholar]
  7. DiMaio D., Settleman J. 1988; Bovine papillomavirus mutant temperature sensitive for transformation, replication and transactivation. EMBO Journal 7:1197–1204
    [Google Scholar]
  8. Dürst M. 1987; Physical state of papillomavirus DNA in tumours. In Papillomaviruses and Human Disease pp. 393–408 Edited by Syrjӓnen K., Gissmann L., Koss L. G. Berlin & Heidelberg: Springer-Verlag;
    [Google Scholar]
  9. Graham F. L., van der Eb A. J. 1973; A new technique for the assay of infectivity of human adenovirus 5 DNA. Virology 52:456–467
    [Google Scholar]
  10. Haugen T. H., Turek L. P., Mercurio F. M., Cripe T. P., Olson B. J., Anderson R. D., Seidl D., Karin M., Schiller J. 1988; Sequence-specific and general transcriptional activation by the bovine papillomavirus-1 E2 transactivator require an N-terminal amphipathic helix-containing E2 domain. EMBO Journal 7:4245–4253
    [Google Scholar]
  11. Hermonat P. L., Spalholz B. A., Howley P. M. 1988; The bovine papillomavirus P2443 promoter is E2 trans-responsive: evidence for E2 autoregulation. EMBO Journal 7:2815–2822
    [Google Scholar]
  12. Hirt B. 1967; Selective extraction of polyoma DNA from infected mouse cell cultures. Journal of Molecular Biology 26:363–369
    [Google Scholar]
  13. Howley P. M. 1991; Papillomavirinae and their replication. In Fundamental Virology pp. 743–768 Edited by Fields B. N., Knipe D. M. New York: Raven Press;
    [Google Scholar]
  14. Knight J. D., Li R., Botchan M. 1991; The activation domain of the bovine papillomavirus E2 protein mediates association of DNA-bound dimers to form DNA loops. Proceedings of the National Academy of Sciences, U.S.A. 88:3204–3208
    [Google Scholar]
  15. Law M. F., Lowy D. R., Dvoretzky I., Howley P. M. 1981; Mouse cells transformed by bovine papillomavirus contain only extrachromosomal viral DNA sequences. Proceedings of the National Academy of Sciences, U.S.A. 78:2727–2731
    [Google Scholar]
  16. Li R., Knight J., Bream G., Stenlund A., Botchan M. 1989; Specific recognition nucleotides and their DNA context determine the affinity of E2 protein for 17 binding sites in the BPV-1 genome. Genes and Development 3:510–526
    [Google Scholar]
  17. Li R., Knight J. D., Jackson S. P., Tjian R., Botchan M. R. 1991; Direct interaction between Spl and the BPV enhancer E2 protein mediates synergistic activation of transcription. Cell 65:493–505
    [Google Scholar]
  18. McBride A. A., Schlegel R., Howley P. M. 1988; The carboxy-terminal domain shared by the bovine papillomavirus E2 trans-activator and repressor proteins contains a specific DNA binding activity. EMBO Journal 7:533–539
    [Google Scholar]
  19. McBride A. A., Bolen J. B., Howley P. M. 1989a; Phosphorylation sites of the E2 transcriptional regulatory proteins of bovine papillomavirus type 1. Journal of Virology 63:5076–5085
    [Google Scholar]
  20. McBride A. A., Byrne J. C., Howley P. M. 1989b; E2 polypeptides encoded by bovine papillomavirus type 1 form dimers through the common carboxy-terminal domain: transactivation is mediated by the conserved amino-terminal domain. Proceedings of the National Academy of Sciences, U.S.A. 86:510–514
    [Google Scholar]
  21. Mohr I. J., Clark R., Sun S., Androphy E. J., MacPherson P., Botchan M. R. 1990; Targeting the El replication protein to the papillomavirus origin of replication by complex formation with the E2 transactivator. Science 250:1694–1699
    [Google Scholar]
  22. Moskaluk C., Bastia D. 1988; DNA bending is induced in an enhancer by the DNA-binding domain of the bovine papillomavirus E2 protein. Proceedings of the National Academy of Sciences, U.S.A. 85:1826–1830
    [Google Scholar]
  23. Sambrook J., Fritsch E. F., Maniatis T. 1989 Molecular Cloning: A laboratory Manual 2nd edn New York: Cold Spring Harbor Laboratory;
    [Google Scholar]
  24. Sanger F., Nicklen S., Coulson A. R. 1977; DNA sequencing with chain-terminating inhibitors. Proceedings of the National Academy of Sciences, U.S.A. 74:5463–5467
    [Google Scholar]
  25. Sarver N., Byrne J. C., Howley P. M. 1982; Transformation and replication in mouse cells of a bovine papillomavirus-pML2 plasmid vector that can be rescued in bacteria. Proceedings of the National Academy of Sciences, U.S.A. 79:7147–7151
    [Google Scholar]
  26. Schiller J. T., Kleiner E., Androphy E. J., Lowy D. R., Pfister H. 1989; Identification of bovine papillomavirus El mutants with increased transforming and transcriptional activity. Journal of Virology 63:1775–1782
    [Google Scholar]
  27. Settleman J., DiMaio D. 1988; Efficient transactivation and morphologic transformation by bovine papillomavirus genes expressed from a bovine papillomavirus/simian virus 40 recombinant virus. Proceedings of the National Academy of Sciences, U.S.A. 85:9007–9011
    [Google Scholar]
  28. Southern E. M. 1975; Detection of specific sequences among DNA fragments separated by gel electrophoresis. Journal of Molecular Biology 98:503–517
    [Google Scholar]
  29. Southern P. J., Berg P. 1982; Transformation of mammalian cells to antibiotic resistance with a bacterial gene under control of the SV40 early region promoter. Journal of Molecular and Applied Genetics 1:327–341
    [Google Scholar]
  30. Spalholz B. A., Yang Y. C., Howley P. M. 1985; Transactivation of a bovine papillomavirus transcriptional regulatory element by the E2 gene product. Cell 42:183–191
    [Google Scholar]
  31. Spalholz B. A., Lambert P. F., Yee C. L., Howley P. M. 1987; Bovine papillomavirus transcriptional regulation: localization of the E2-responsive elements of the long control region. Journal of Virology 61:2128–2137
    [Google Scholar]
  32. Spalholz B. A., Van de Pol S. B., Howley P. M. 1991; Characterization of the cis elements involved in basal and E2-transactivated expression of the bovine papillomavirus P2443 promoter. Journal of Virology 65:743–753
    [Google Scholar]
  33. Szymanski P., Stenlund A. 1991; Regulation of early gene expression from the bovine papillomavirus genome in transiently transfected Cl27 cells. Journal of Virology 65:5710–5720
    [Google Scholar]
  34. Ustav M., Stenlund A. 1991; Transient replication of BPV-1 requires two viral polypeptides encoded by the E1 and E2 open reading frames. EMBO Journal 10:449–457
    [Google Scholar]
  35. Ustav M., Ustav E., Szymanski P., Stenlund A. 1991; Identification of the origin of replication of bovine papillomavirus and characterization of the viral origin recognition factor E1. EMBO Journal 10:4321–4329
    [Google Scholar]
  36. Van de Pol S. B., Howley P. M. 1992; The bovine papillomavirus constitutive enhancer is essential for viral transformation, DNA replication, and the maintenance of latency. Journal of Virology 66:2346–2358
    [Google Scholar]
  37. Wilson V. G., Ludes-Meyer J. 1991; A bovine papillomavirus El-related protein binds specifically to bovine papillomavirus DNA. Journal of Virology 65:5314–5322
    [Google Scholar]
  38. Yang L., Botchan M. 1990; Replication of bovine papillomavirus type 1 DNA initiates within an E2-responsive enhancer element. Journal of Virology 64:5903–5911
    [Google Scholar]
  39. Yang L., Li R., Mohr I. J., Clark R., Botchan M. R. 1991; Activation of BPV-1 replication in vitro by the transcription factor E2. Nature, London 353:628–632
    [Google Scholar]
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