title: West Nile Virus NS2B/NS3 protease as an antiviral target.
abstract: West Nile Virus (WNV) has spread rapidly during the last decade across five continents causing disease and fatalities in humans and mammals. It highlights the serious threat to both our health and the economy posed by viruses crossing species, in this case from migratory birds via mosquitoes to mammals. There is no vaccine or antiviral drug for treating WNV infection. One attractive target for antiviral development is a viral trypsin-like serine protease, encoded by the N-terminal 184 amino acids of NS3, which is only active when tethered to its cofactor, NS2B. This protease, NS2B/NS3pro, cleaves the viral polyprotein to release structural and non-structural viral proteins that are essential in viral replication and assembly of new virus particles. Disruption of this protease activity is lethal for virus replication. The NS3 protein also has other enzymes within its sequence (helicase, nucleoside triphosphatase, RNA triphosphatase), all of which are tightly regulated through localisation within membranous compartments in the infected cell. This review describes the various roles of NS3, focussing on NS2B-NS3 protease and its function and regulation in WNV replication and infection. Current advances towards development of antiviral inhibitors of NS2B/NS3pro are examined along with obstacles to their development as an antiviral therapy.
authors.affiliation: School of Molecular and Microbial Sciences and Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia.
authors.forename: K J
authors.initials: KJ
authors.lastname: Chappell
authors.forename: M J
authors.initials: MJ
authors.lastname: Stoermer
authors.forename: D P
authors.initials: DP
authors.lastname: Fairlie
authors.forename: P R
authors.initials: PR
authors.lastname: Young
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D008958:Models, Molecular; D015394:Molecular Structure; D011480:Protease Inhibitors / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D020365:RNA Helicases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D012697:Serine Endopeptidases / Q000737:chemistry / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects; D014901:West Nile Fever / Q000188:drug therapy; D014902:West Nile virus / Q000201:enzymology*; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D000998:Antiviral Agents; D011480:Protease Inhibitors; D020365:RNA Helicases; D012697:Serine Endopeptidases; D017361:Viral Nonstructural Proteins; C080102:NS2B protein, flavivirus; C060028:NS3 protein, flavivirus; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases