title: Discovery of a novel antiviral agent targeting the nonstructural protein 4 (nsP4) of chikungunya virus.
abstract: Chikungunya fever (CHIKF) is caused by chikungunya virus (CHIKV) infection which is a re-emerging mosquito-borne zoonosis. At present, there are no approved therapeutics for CHIKF. Herein, we have investigated candidate compounds which can inhibit CHIKV infection. Screening of chemical compound libraries were performed and one candidate, a benzimidazole-related compound designated Compound-A was found to inhibit infection by several CHIKV strains and a Sindbis virus strain at nanomolar concentrations. To investigate the inhibitory mechanism of action, a Compound-A resistant CHIKV (res-CHIKV) was isolated and a key mutation associated with resistance was identified by reverse-genetic recombinant CHIKVs containing amino acid substitutions present in res-CHIKV. These results demonstrated that the target site of Compound-A was the M2295 residue in the nonstructural protein 4 (nsP4), which is located in one of the functional domains of RNA-dependent RNA-polymerase (RdRp). We also confirmed that Compound-A inhibits RdRp function of CHIKV by using CHIKV replicons.
authors.affiliation: Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Wada
authors.affiliation: Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Orba
authors.affiliation: Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Michihito
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido, Japan; National Virus Reference Laboratory, University College Dublin, Belfield, Ireland.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Carr
authors.affiliation: Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan; Discovery Research Laboratory for Core Therapeutic Areas, Shionogi & Co., Ltd., Toyonaka, Osaka, Japan.
authors.forename: Haruaki
authors.initials: H
authors.lastname: Nobori
authors.affiliation: Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan; Discovery Research Laboratory for Core Therapeutic Areas, Shionogi & Co., Ltd., Toyonaka, Osaka, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sato
authors.affiliation: Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido, Japan; National Virus Reference Laboratory, University College Dublin, Belfield, Ireland; Global Virus Network, 801 W. Baltimore, MD, United States.
authors.forename: William W
authors.initials: WW
authors.lastname: Hall
authors.affiliation: Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan; Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido, Japan; Global Virus Network, 801 W. Baltimore, MD, United States. Electronic address: h-sawa@czc.hokudai.ac.jp.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Sawa
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D001483:Base Sequence; D001562:Benzimidazoles / Q000494:pharmacology*; D065632:Chikungunya Fever / Q000188:drug therapy / Q000821:virology; D002646:Chikungunya virus / Q000187:drug effects* / Q000235:genetics; D002522:Chlorocebus aethiops; D024882:Drug Resistance, Viral / Q000235:genetics*; D057809:HEK293 Cells; D006801:Humans; D012324:RNA-Dependent RNA Polymerase / Q000037:antagonists & inhibitors* / Q000235:genetics; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA; D014709:Vero Cells; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D001562:Benzimidazoles; D017361:Viral Nonstructural Proteins; C000619339:compound A (benzimidazole); C000619338:nsP4 protein, Chikungunya virus; D012324:RNA-Dependent RNA Polymerase
keywords: Antiviral compound; Chikungunya virus; RdRp inhibitor