title: ICln channels reconstituted in heart-lipid bilayer are selective to chloride.
abstract: ICln is an ion channel cloned from renal epithelial cells. The reconstitution of the protein in 1,2-diphytanoyl- sn-glycero-3-phosphocholine (Diph-PC) bilayer membranes reveals potassium-selective channels, which become more chloride selective in the presence of calcium. Here we show that the ion selectivity of ICln also depends on the lipid environment in which the channels are reconstituted. Diph-PC is a synthetic lipid commonly used for reconstituting ion channels. However, since this lipid is not found in native membranes, we reconstituted the ICln ion channels in a polar heart-lipid extract. Using this lipid mixture the reconstituted ICln ion channels are chloride selective in the presence of calcium and an acidic pH. The relative ion selectivity of ICln under these conditions is similar to the cation versus anion selectivity of native ion channels activated by cell swelling.
authors.affiliation: Institute of Physiology, University of Innsbuck, Austria.
authors.forename: Maria Lisa
authors.initials: ML
authors.lastname: Garavaglia
authors.forename: Simona
authors.initials: S
authors.lastname: Rodighiero
authors.forename: Christina
authors.initials: C
authors.lastname: Bertocchi
authors.forename: Rosangela
authors.initials: R
authors.lastname: Manfredi
authors.forename: Johannes
authors.initials: J
authors.lastname: Fürst
authors.forename: Martin
authors.initials: M
authors.lastname: Gschwentner
authors.forename: Markus
authors.initials: M
authors.lastname: Ritter
authors.forename: Claudia
authors.initials: C
authors.lastname: Bazzini
authors.forename: Guido
authors.initials: G
authors.lastname: Bottà
authors.forename: Martin
authors.initials: M
authors.lastname: Jakab
authors.forename: Giuliano
authors.initials: G
authors.lastname: Meyer
authors.forename: Markus
authors.initials: M
authors.lastname: Paulmichl
mesh_terms: D000143:Acids / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002712:Chlorides / Q000493:pharmacokinetics*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D007473:Ion Channels; D008051:Lipid Bilayers / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009206:Myocardium / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000494:pharmacology*; D011506:Proteins / Q000502:physiology*
chemical_list: D000143:Acids; C410035:CLNS1A protein, human; D002712:Chlorides; D007473:Ion Channels; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D011506:Proteins; C021016:1,2-diphytanoylphosphatidylcholine; D008274:Magnesium; D002118:Calcium