title: Lipids driving protein structure? Evolutionary adaptations in Kir channels.
abstract: Many eukaryotic channels, transporters and receptors are activated by phosphatidyl inositol bisphosphate (PIP(2)) in the membrane, and every member of the eukaryotic inward rectifier potassium (Kir) channel family requires membrane PIP(2) for activity. In contrast, a bacterial homolog (KirBac1.1) is specifically inhibited by PIP(2). We speculate that a key evolutionary adaptation in eukaryotic channels is the insertion of additional linkers between transmembrane and cytoplasmic domains, revealed by new crystal structures, that convert PIP(2) inhibition to activation. Such an adaptation may reflect a novel evolutionary drive to protein structure, and that was necessary to permit channel function within the highly negatively charged membranes that evolved in the eukaryotic lineage.
authors.affiliation: Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Nazzareno
authors.initials: N
authors.lastname: D'Avanzo
authors.forename: Wayland W L
authors.initials: WW
authors.lastname: Cheng
authors.forename: Shizhen
authors.initials: S
authors.lastname: Wang
authors.forename: Decha
authors.initials: D
authors.lastname: Enkvetchakul
authors.forename: Colin G
authors.initials: CG
authors.lastname: Nichols
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D056890:Eukaryota / Q000737:chemistry; D019143:Evolution, Molecular; D008563:Membrane Lipids / Q000502:physiology*; D024661:Potassium Channels, Inwardly Rectifying / Q000737:chemistry* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D008563:Membrane Lipids; D024661:Potassium Channels, Inwardly Rectifying