1887

Abstract

Hepatitis C virus (HCV) is an important cause of chronic liver disease, but the molecular mechanisms of viral pathogenesis remain to be established. The HCV non-structural protein NS3 complexes with NS4A and has three enzymatic activities: a proteinase and a helicase/NTPase. Recently, catalytically inactive NS3 fragments containing an arginine-rich motif have been reported to interact with, and inhibit, the catalytic subunit of cAMP-dependent protein kinase (PKA C-subunit). Here we demonstrate that full-length, catalytically active NS3/4A, purified from recombinant baculovirus-infected insect cells, is also able to inhibit PKA C-subunit . This inhibition was abrogated by mutation of either the arginine-rich motif or the conserved helicase motif II, both of which also abolished NTPase activity. As PKA C-subunit inhibition was also enhanced by poly(U) (an activator of NS3 NTPase activity), we hypothesized that PKA C-subunit inhibition could be due to NS3/4A-mediated ATP hydrolysis. This was confirmed by experiments in which a constant ATP concentration was maintained by addition of an ATP regeneration system – under these conditions PKA C-subunit inhibition was not observed. Interestingly, the mutations also abrogated the ability of wild-type NS3/4A to inhibit the PKA-regulated transcription factor CREB in transiently transfected hepatoma cells. Our data are thus not consistent with the previously proposed model in which the arginine-rich motif of NS3 was suggested to act as a pseudosubstrate inhibitor of PKA C-subunit. However, effects of NS3/4A suggest that ATPase activity may play a role in viral pathology in the infected liver.

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2001-07-01
2024-04-19
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References

  1. Bartenschlager R. 1999; The NS3/4A proteinase of the hepatitis C virus: unravelling structure and function of an unusual enzyme and a prime target for antiviral therapy. Journal of Viral Hepatitis 6:165–181
    [Google Scholar]
  2. Bartenschlager R., Lohmann V. 2000; Replication of hepatitis C virus. Journal of General Virology 81:1631–1648
    [Google Scholar]
  3. Booth J. C. L. 1998; Chronic hepatitis C: the virus, its discovery and the natural history of the disease. Journal of Viral Hepatitis 5:213–222
    [Google Scholar]
  4. Borowski P., Heiland M., Oehlmann K., Becker B., Kornetzky L., Feucht H., Laufs R. 1996; Nonstructural protein-3 of hepatitis-C virus inhibits phosphorylation mediated by cAMP-dependent protein-kinase. European Journal of Biochemistry 237:611–618
    [Google Scholar]
  5. Borowski P., Oehlmann K., Heiland M., Laufs R. 1997; Nonstructural protein 3 of hepatitis C virus blocks the distribution of the free catalytic subunit of cyclic AMP-dependent protein kinase. Journal of Virology 71:2838–2843
    [Google Scholar]
  6. Choo Q. L., Kuo G., Weiner A. J., Overby L. R., Bradley D. W., Houghton M. 1989; Isolation of a cDNA clone derived from a blood-borne non-A, non-B viral-hepatitis genome. Science 244:359–362
    [Google Scholar]
  7. Clarke B. 1997; Molecular biology of hepatitis C virus. Journal of General Virology 78:2397–2410
    [Google Scholar]
  8. Della Fazia M. A., Servillo G., Sassone Corsi P. 1997; Cyclic AMP signalling and cellular proliferation: regulation of CREB and CREM. FEBS Letters 410:22–24
    [Google Scholar]
  9. Edwards A. S., Scott J. D. 2000; A-kinase anchoring proteins: protein kinase A and beyond. Current Opinion in Cell Biology 12:217–221
    [Google Scholar]
  10. Errington W., Wardell A. D., McDonald S., Goldin R. D., McGarvey M. J. 1999; Subcellular localisation of NS3 in HCV-infected hepatocytes. Journal of Medical Virology 59:456–462
    [Google Scholar]
  11. Francis S. H., Corbin J. D. 1994; Structure and function of cyclic nucleotide-dependent protein-kinases. Annual Review of Physiology 56:237–272
    [Google Scholar]
  12. Fujita T., Ishido S., Muramatsu S., Itoh M., Hotta H. 1996; Suppression of actinomycin D-induced apoptosis by the NS3 protein of hepatitis C virus. Biochemical and Biophysical Research Communications 229:825–831
    [Google Scholar]
  13. Green S., Issemann I., Sheer E. 1988; A versatile in vivo and in vitro eukaryotic expression vector for protein engineering. Nucleic Acids Research 16:369
    [Google Scholar]
  14. Higuchi R. 1992; Using PCR to engineer DNA. In PCR Technology Principles and Applications pp 61–70 Edited by Erlich H. A. New York: W. H. Freeman;
    [Google Scholar]
  15. Kadare G., Haenni A. L. 1997; Virus-encoded RNA helicases. Journal of Virology 71:2583–2590
    [Google Scholar]
  16. Kholodenko B., Zilinskiene V., Borutaite V., Ivanoviene L., Toleikis A., Praskevicius A. 1987; The role of adenine-nucleotide translocators in regulation of oxidative-phosphorylation in heart-mitochondria. FEBS Letters 223:247–250
    [Google Scholar]
  17. Kim J. L., Morgenstern K. A., Lin C., Fox T., Dwyer M. D., Landro J. A., Chambers S. P., Markland W., Lepre C. A., Omalley E. T., Harbeson S. L., Rice C. M., Murcko M. A., Caron P. R., Thomson J. A. 1996; Crystal-structure of the hepatitis-C virus NS3 protease domain complexed with a synthetic NS4A cofactor peptide. Cell 87:343–355
    [Google Scholar]
  18. Kitts P. A., Ayers M. D., Possee R. D. 1990; Linearization of baculovirus DNA enhances recovery of recombinant virus expression vectors. Nucleic Acids Research 18:5667–5672
    [Google Scholar]
  19. Kolykhalov A. A., Mihalik K., Feinstone S. M., Rice C. M. 2000; Hepatitis C virus-encoded enzymatic activities and conserved RNA elements in the 3′ nontranslated region are essential for virus replication in vivo. Journal of Virology 74:2046–2051
    [Google Scholar]
  20. Kummerer B. M., Stoll D., Meyers G. 1998; Bovine viral diarrhea virus strain Oregon: a novel mechanism for processing of NS2-3 based on point mutations. Journal of Virology 72:4127–4138
    [Google Scholar]
  21. Lemon S. M., Honda M. 1997; Internal ribosome entry sites within the RNA genomes of hepatitis C virus and other flaviviruses. Seminars in Virology 8:274–288
    [Google Scholar]
  22. Maniatis T., Fritsch E. F., Sambrook J. 1989 Molecular Cloning: A Laboratory Manual, 2nd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
  23. Olsen S. R., Uhler M. D. 1991; Isolation and characterization of cDNA clones for an inhibitor protein of cAMP-dependent protein kinase. Journal of Biological Chemistry 266:11158–11162
    [Google Scholar]
  24. Pause A., Methot N., Sonenberg N. 1993; The HRIGRXXR region of the DEAD box RNA helicase eukaryotic translation initiation factor-4a is required for RNA-binding and ATP hydrolysis. Molecular and Cellular Biology 13:6789–6798
    [Google Scholar]
  25. Roskoski R. J. 1983; Assays of protein kinase. Methods in Enzymology 99:3–6
    [Google Scholar]
  26. Saito I., Miyamura T., Ohbayashi A., Harada H., Katayama T., Kikuchi S., Watanabe Y., Koi S., Onji M., Ohta Y., Choo Q. L., Houghton M., Kuo G. 1990; Hepatitis-C virus-infection is associated with the development of hepatocellular-carcinoma. Proceedings of the National Academy of Sciences, USA 87:6547–6549
    [Google Scholar]
  27. Sakamuro D., Furukawa T., Takegami T. 1995; Hepatitis C virus nonstructural protein NS3 transforms NIH 3T3 cells. Journal of Virology 69:3893–3896
    [Google Scholar]
  28. Sali D. L., Ingram R., Wendel M., Gupta D., McNemar C., Tsarbopoulos A., Chen J. W., Hong Z., Chase R., Risano C., Zhang R. M., Yao N. H., Kwong A. D., Ramanathan L., Le H. V., Weber P. C. 1998; Serine protease of hepatitis C virus expressed in insect cells as the NS3/4A complex. Biochemistry 37:3392–3401
    [Google Scholar]
  29. Scott J. D., Stofko R. E., McDonald J. R., Comer J. D., Vitalis E. A., Mangili J. A. 1990; Type-II regulatory subunit dimerization determines the subcellular-localization of the cAMP-dependent protein-kinase. Journal of Biological Chemistry 265:21561–21566
    [Google Scholar]
  30. Spengler U., Lechmann M., Irrgang B., Dumoulin F. L., Sauerbruch T. 1996; Immune responses in hepatitis C virus infection. Journal of Hepatology 24:20–25
    [Google Scholar]
  31. Tautz N., Meyers G., Stark R., Dubovi E. J., Thiel H. J. 1996; Cytopathogenicity of a pestivirus correlates with a 27-nucleotide insertion. Journal of Virology 70:7851–7858
    [Google Scholar]
  32. Walsh D. A., Van Patten S. M. 1994; Multiple pathway signal-transduction by the cAMP-dependent protein-kinase. FASEB Journal 8:1227–1236
    [Google Scholar]
  33. Wardell A. D., Errington W., Ciaramella G., Merson J., McGarvey M. J. 1999; Characterization and mutational analysis of the helicase and NTPase activities of hepatitis C virus full-length NS3 protein. Journal of General Virology 80:701–709
    [Google Scholar]
  34. Whitehouse S., Feramisco J. R., Casnellie J. E., Krebs E. G., Walsh D. A. 1983; Studies on the kinetic mechanism of the catalytic subunit of the cAMP-dependent protein-kinase. Journal of Biological Chemistry 258:3693–3701
    [Google Scholar]
  35. Winder W. W., Hardie D. G. 1999; AMP-activated protein kinase, a metabolic master switch: possible roles in Type 2 diabetes. American Journal of Physiology–Endocrinology And Metabolism 40:E1–E10
    [Google Scholar]
  36. Yan Y. W., Li Y., Munshi S., Sardana V., Cole J. L., Sardana M., Steinkuehler C., Tomei L., Defrancesco R., Kuo L. C., Chen Z. G. 1998; Complex of NS3 protease and NS4A peptide of BK strain hepatitis C virus: a 2·2 angstrom resolution structure in a hexagonal crystal form. Protein Science 7:837–847
    [Google Scholar]
  37. Yanagi M., Purcell R. H., Emerson S. U., Bukh J. 1997; Transcripts from a single full-length cDNA clone of hepatitis C virus are infectious when directly transfected into the liver of a chimpanzee. Proceedings of the National Academy of Sciences, USA 94:8738–8743
    [Google Scholar]
  38. Yao N. H., Reichert P., Taremi S. S., Prosise W. W., Weber P. C. 1999; Molecular views of viral polyprotein processing revealed by the crystal structure of the hepatitis C virus bifunctional protease–helicase. Structure With Folding & Design 7:1353–1363
    [Google Scholar]
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