Multiple Enzyme Activities of Flavivirus Proteins

  1. Gregory Bock Organizer and
  2. Jamie Goode
  1. R. Padmanabhan1,
  2. N. Mueller2,
  3. E. Reichert2,
  4. C. Yon2,
  5. T. Teramoto2,
  6. Y. Kono2,
  7. R. Takhampunya2,3,
  8. S. Ubol3,
  9. N. Pattabiraman4,
  10. B. Falgout5,
  11. V. K. Ganesh6 and
  12. K. Murthy6

Published Online: 7 OCT 2008

DOI: 10.1002/0470058005.ch6

New Treatment Strategies for Dengue and Other Flaviviral Diseases: Novartis Foundation Symposium 277

New Treatment Strategies for Dengue and Other Flaviviral Diseases: Novartis Foundation Symposium 277

How to Cite

Padmanabhan, R., Mueller, N., Reichert, E., Yon, C., Teramoto, T., Kono, Y., Takhampunya, R., Ubol, S., Pattabiraman, N., Falgout, B., Ganesh, V. K. and Murthy, K. (2008) Multiple Enzyme Activities of Flavivirus Proteins, in New Treatment Strategies for Dengue and Other Flaviviral Diseases: Novartis Foundation Symposium 277 (eds G. Bock and J. Goode), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/0470058005.ch6

Author Information

  1. 1

    Department of Microbiology and Immunology, Georgetown University Medical Centre, SW309 Medical-Dental Building, 3900 Reservoir Rd, Washington DC 20057, USA

  2. 2

    Department of Microbiology and Immunology, USA

  3. 3

    Department of Microbiology, Mahidol University, Bangkok, Thailand

  4. 4

    Lombardi Cancer Center, Georgetown University School of Medicine, Washington DC, USA

  5. 5

    CBER, FDA, Bethesda, MD, USA

  6. 6

    University of Alabama-Birmingham, AL, USA

Publication History

  1. Published Online: 7 OCT 2008
  2. Published Print: 25 AUG 2006

Book Series:

  1. Novartis Foundation Symposia

Book Series Editors:

  1. Novartis Foundation

ISBN Information

Print ISBN: 9780470016435

Online ISBN: 9780470058008

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Keywords:

  • flavivirus enzyme activities;
  • cell-based DENV-2 replicon RNA and cis-acting elements;
  • NS3/NS5 complex modulating NS3 activities;
  • in vitro RNA dependent RNA polymerase assays;
  • in vitro assays in antiviral therapeutics

Summary

Dengue viruses (DENV) have 5′-capped RNA genomes of (+) polarity and encode a single polyprotein precursor that is processed into mature viral proteins. NS2B, NS3 and NS5 proteins catalyse/activate enzyme activities that are required for key processes in the virus life cycle. The heterodimeric NS2B/NS3 is a serine protease required for processing. Using a high-throughput protease assay, we screened a small molecule chemical library and identified ∼200 compounds having ≥50% inhibition. Moreover, NS3 exhibits RNA-stimulated NTPase, RNA helicase and the 5′-RNA triphosphatase activities. The NTPase and the 5′-RTPase activities of NS3 are stimulated by interaction with NS5. Moreover, the conserved, positively charged motif in DENV-2 NS3, 184RKRK, is required for RNA binding and modulates the RNA-dependent enzyme activities of NS3. To study viral replication, a variety of methods are used such as the in vitro RNAdependent RNA polymerase assays that utilize lysates from DENV-2-infected mosquito- or mammalian cells or the purified NS5 along with exogenous short subgenomic viral RNAs or the replicative intracellular membrane-bound viral RNAs as templates. In addition, a cell-based DENV-2 replicon RNA encoding a luciferase reporter is also used to examine the role of cis-acting elements within the 3′ UTR and the RKRK motif in viral replication.