title: Viroporins.
abstract: Viroporins are a group of proteins that participate in several viral functions, including the promotion of release of viral particles from cells. These proteins also affect cellular functions, including the cell vesicle system, glycoprotein trafficking and membrane permeability. Viroporins are not essential for the replication of viruses, but their presence enhances virus growth. Comprising some 60-120 amino acids, viroporins have a hydrophobic transmembrane domain that interacts with and expands the lipid bilayer. Some viroporins also contain other motifs, such as basic amino acid residues or a domain rich in aromatic amino acids that confers on the protein the ability to interact with the interfacial lipid bilayer. Viroporin oligomerization gives rise to hydrophilic pores at the membranes of virus-infected cells. As the list of known viroporins steadily grows, recent research efforts focus on deciphering the actions of the viroporins poliovirus 2B, alphavirus 6K, HIV-1 Vpu and influenza virus M2. All these proteins can enhance the passage of ions and small molecules through membranes depending on their concentration gradient. Future work will lengthen the list of viroporins and will provide a deeper understanding of their mechanisms of action.
authors.affiliation: Unidad de Expresión Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Majadahonda-Pozuelo Km 2, 28220 Majadahonda, Madrid, Spain. megonzalez@isciii.es
authors.forename: Maria Eugenia
authors.initials: ME
authors.lastname: Gonzalez
authors.forename: Luis
authors.initials: L
authors.lastname: Carrasco
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D000998:Antiviral Agents / Q000494:pharmacology; D002462:Cell Membrane / Q000821:virology; D002463:Cell Membrane Permeability; D054298:Human Immunodeficiency Virus Proteins; D007473:Ion Channels / Q000737:chemistry; D008051:Lipid Bilayers / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010849:Picornaviridae / Q000737:chemistry; D017434:Protein Structure, Tertiary; D014759:Viral Envelope Proteins / Q000737:chemistry*; D014763:Viral Matrix Proteins / Q000737:chemistry; D054334:Viral Regulatory and Accessory Proteins / Q000737:chemistry*; D014780:Viruses / Q000737:chemistry*; D000086082:Viroporin Proteins
chemical_list: D000596:Amino Acids; D000998:Antiviral Agents; D054298:Human Immunodeficiency Virus Proteins; D007473:Ion Channels; D008051:Lipid Bilayers; D014759:Viral Envelope Proteins; D014763:Viral Matrix Proteins; D054334:Viral Regulatory and Accessory Proteins; C031540:M-protein, influenza virus; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins; C514859:vpu protein, Human immunodeficiency virus 1