Williams E Miranda1, Jiqing Guo2, Haydee Mesa-Galloso1, Valentina Corradi1, James P Lees-Miller2, D Peter Tieleman3, Henry J Duff4, Sergei Yu Noskov5. 1. Centre for Molecular Simulation and Department of Biological Sciences, 507 Campus Drive, University of Calgary, Calgary, AB, Canada. 2. Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, 3280 Hospital Dr., University of Calgary, Calgary, AB, Canada. 3. Centre for Molecular Simulation and Department of Biological Sciences, 507 Campus Drive, University of Calgary, Calgary, AB, Canada. tieleman@ucalgary.ca. 4. Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, 3280 Hospital Dr., University of Calgary, Calgary, AB, Canada. hduff@ucalgary.ca. 5. Centre for Molecular Simulation and Department of Biological Sciences, 507 Campus Drive, University of Calgary, Calgary, AB, Canada. snoskov@ucalgary.ca.
Abstract
The lipid regulation of mammalian ion channel function has emerged as a fundamental mechanism in the control of electrical signalling and transport specificity in various cell types. In this work, we combine molecular dynamics simulations, mutagenesis, and electrophysiology to provide mechanistic insights into how lipophilic molecules (ceramide-sphingolipid probe) alter gating kinetics and K+ currents of hERG1. We show that the sphingolipid probe induced a significant left shift of activation voltage, faster deactivation rates, and current blockade comparable to traditional hERG1 blockers. Microseconds-long MD simulations followed by experimental mutagenesis elucidated ceramide specific binding locations at the interface between the pore and voltage sensing domains. This region constitutes a unique crevice present in mammalian channels with a non-swapped topology. The combined experimental and simulation data provide evidence for ceramide-induced allosteric modulation of the channel by a conformational selection mechanism.
The lipid regulation of n class="Species">mammalian ion channel function has emerged as a fundamental mechanism in the control of electrical signalling and transport specificity in various cell types. In this work, we combine molecular dynamics simulations, mutagenesis, and electrophysiology to provide mechanistic insights into how lipophilic molecules (ceramide-sphingolipid probe) alter gating kinetics and K+ currents of hERG1. We show that the sphingolipid probe induced a significant left shift of activation voltage, faster deactivation rates, and current blockade comparable to traditional hERG1 blockers. Microseconds-long MD simulations followed by experimental mutagenesis elucidated ceramide specific binding locations at the interface between the pore and voltage sensing domains. This region constitutes a unique crevice present in mammalian channels with a non-swapped topology. The combined experimental and simulation data provide evidence for ceramide-induced allosteric modulation of the channel by a conformational selection mechanism.
Authors: Laura Perissinotti; Jiqing Guo; Meruyert Kudaibergenova; James Lees-Miller; Marina Ol'khovich; Angelica Sharapova; German L Perlovich; Daniel A Muruve; Brenda Gerull; Sergei Yu Noskov; Henry J Duff Journal: Mol Pharmacol Date: 2019-06-10 Impact factor: 4.436
Authors: Lauren K Park; Valene Garr Barry; Juan Hong; John Heebink; Rajan Sah; Linda R Peterson Journal: Curr Opin Lipidol Date: 2022-02-01 Impact factor: 4.616