Coronavirus E protein forms ion channels with functionally and structurally-involved membrane lipids

• Published in: Virology (New York, N.Y.) Vol. 432; no. 2; pp. 485 - 494
• Main Authors: Verdiá-Báguena, Carmina, Nieto-Torres, Jose L, Alcaraz, Antonio, DeDiego, Marta L, Torres, Jaume, Aguilella, Vicente M, Enjuanes, Luis
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 25.10.2012
• Subjects: Amino Acid Sequence; Cations; Channel pores; Conductance; Coronavirus; Coronavirus 229E, Human - metabolism; Envelope protein; Envelopes; HCoV-229E; Humans; Infectious Disease; Ion channel; Ion channels; Ion Channels - metabolism; Lipid bilayers; Lipid composition; Lipid membranes; Membrane Lipids - metabolism; Molecular Sequence Data; Mutation; SARS; SARS coronavirus; SARS Virus - metabolism; Severe acute respiratory syndrome; Transmembrane domains; Viral Envelope Proteins - chemistry; Viral Envelope Proteins - genetics; Viral Envelope Proteins - metabolism; Viroporin Proteins; Envelope protein; Lipid membranes; SARS; Coronavirus; HCoV-229E; Ion channel
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2012.07.005

Abstract Coronavirus (CoV) envelope (E) protein ion channel activity was determined in channels formed in planar lipid bilayers by peptides representing either the transmembrane domain of severe acute respiratory syndrome CoV (SARS-CoV) E protein, or the full-length E protein. Both of them formed a voltage independent ion conductive pore with symmetric ion transport properties. Mutations N15A and V25F located in the transmembrane domain prevented the ion conductivity. E protein derived channels showed no cation preference in non-charged lipid membranes, whereas they behaved as pores with mild cation selectivity in negatively-charged lipid membranes. The ion conductance was also controlled by the lipid composition of the membrane. Lipid charge also regulated the selectivity of a HCoV-229E E protein derived peptide. These results suggested that the lipids are functionally involved in E protein ion channel activity, forming a protein–lipid pore, a novel concept for CoV E protein ion channel entity.