Hexamethylene amiloride blocks E protein ion channels and inhibits coronavirus replication.
All coronaviruses encode a small hydrophobic envelope (E) protein, which mediates viral assembly and morphogenesis by an unknown mechanism. We have previously shown that the E protein from Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) forms cation-selective ion channels in planar lipid bilayers (Wilson, L., McKinlay, C., Gage, P., Ewart, G., 2004. SARS coronavirus E protein forms cation-selective ion channels. Virology 330(1), 322-331). We now report that three other E proteins also form cation-selective ion channels. These E proteins were from coronaviruses representative of taxonomic groups 1-3: human coronavirus 229E (HCoV-229E), mouse hepatitis virus (MHV), and infectious bronchitis virus (IBV), respectively. It appears, therefore, that coronavirus E proteins in general, belong to the virus ion channels family. Hexamethylene amiloride (HMA)--an inhibitor of the HIV-1 Vpu virus ion channel--inhibited the HCoV-229E and MHV E protein ion channel conductance in bilayers and also inhibited replication of the parent coronaviruses in cultured cells, as determined by plaque assay. Conversely, HMA had no antiviral effect on a recombinant MHV with the entire coding region of E protein deleted (MHVDeltaE). Taken together, the data provide evidence of a link between inhibition of E protein ion channel activity and the antiviral activity of HMA.
Wilson
Lauren
L
ANU Medical School, Pathology Building 10, 6th floor, The Canberra Hospital, Woden ACT 2606, Australia. lauren.wilson@anu.edu.au
Gage
Peter
P
Ewart
Gary
G
D000584:Amiloride / Q000031:analogs & derivatives* / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D002460:Cell Line; D017934:Coronavirus / Q000235:genetics / Q000502:physiology*; D006801:Humans; D015640:Ion Channel Gating; D007473:Ion Channels / Q000037:antagonists & inhibitors*; D051379:Mice; D008969:Molecular Sequence Data; D026941:Sodium Channel Blockers / Q000494:pharmacology*; D014759:Viral Envelope Proteins / Q000037:antagonists & inhibitors*; D014779:Virus Replication / Q000187:drug effects
D000998:Antiviral Agents; D007473:Ion Channels; D026941:Sodium Channel Blockers; D014759:Viral Envelope Proteins; C057360:5-(N,N-hexamethylene)amiloride; D000584:Amiloride