title: The antiviral compound enviroxime targets the 3A coding region of rhinovirus and poliovirus.
abstract: Enviroxime is an antiviral compound that inhibits the replication of rhinoviruses and enteroviruses. We have explored the mechanism of action of enviroxime by using poliovirus type 1 and human rhinovirus type 14 as model systems. By varying the time of drug addition to virus-infected cells, we determined that enviroxime could be added several hours postinfection without significant loss of inhibition. This suggested that the drug targeted a step involved in RNA replication or protein processing. To identify this target, we mapped 23 independent mutations in mutants that could multiply in the presence of 1 microgram of enviroxime per ml. Each of these mutants contained a single nucleotide substitution that altered one amino acid in the 3A coding region. Using oligonucleotide-directed mutagenesis of cDNA clones, we have confirmed that these single-amino-acid substitutions are sufficient to confer the resistance phenotype. In addition, we conducted two experiments to support the hypothesis that enviroxime inhibits a 3A function. First, we determined by dot blot analysis of RNA from poliovirus-infected cells that enviroxime preferentially inhibits synthesis of the viral plus strand. Second, we demonstrated that enviroxime inhibits the initiation of plus-strand RNA synthesis as measured by the addition of [32P]uridine to 3AB in poliovirus crude replication complexes. To our knowledge, this is the first evidence that 3A can be targeted by antiviral drugs. We anticipate that enviroxime will be a useful tool for investigating the natural function of the 3A protein.
authors.affiliation: Infectious Disease Research, Lilly Research Laboratories, Indianapolis, Indiana 46285, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Heinz
authors.forename: L M
authors.initials: LM
authors.lastname: Vance
mesh_terms: D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000494:pharmacology*; D001483:Base Sequence; D001562:Benzimidazoles / Q000494:pharmacology*; D004351:Drug Resistance; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010091:Oximes; D017955:Poliovirus / Q000187:drug effects* / Q000235:genetics; D012367:RNA, Viral / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D012229:Rhinovirus / Q000187:drug effects* / Q000235:genetics; D013449:Sulfonamides; D014529:Uridine / Q000378:metabolism; D014758:Viral Core Proteins / Q000235:genetics* / Q000502:physiology
chemical_list: D000998:Antiviral Agents; D001562:Benzimidazoles; D010091:Oximes; D012367:RNA, Viral; D013449:Sulfonamides; D014758:Viral Core Proteins; C021595:viroxime; D014529:Uridine