title: Osmotic swelling activates a novel anionic current with VRAC-like properties in a cytoplasmic droplet membrane from Phycomyces blakesleeanus sporangiophores.
abstract: We describe here whole-cell currents of droplets prepared from the apical region of growing Phycomyces blakesleeanus sporangiophores. Whole-cell current recordings revealed the osmotically activated, outwardly rectifying, fast inactivating instantaneous current (ORIC) with biophysical properties closely resembling volume-regulated anionic current (VRAC). ORIC is activated under conditions of osmotically induced swelling and shows strong selectivity for anions over cations. In addition, ORIC shows voltage and time-dependent inactivation at positive potentials and recovery from inactivation at negative potentials. ORIC is blocked by anthracene-9-carboxylic acid, an anion channel blocker, in a voltage-dependent manner. This is the first report of the presence of VRAC-like current in an organism outside the chordate lineage.
authors.affiliation: Department of Life Sciences, Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia. Electronic address: strahinjakrizak@imsi.bg.ac.rs.
authors.forename: Strahinja
authors.initials: S
authors.lastname: Križak
authors.affiliation: Department of Neurophysiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia. Electronic address: ljnikolic@ibiss.bg.ac.rs.
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Nikolić
authors.affiliation: Department of Life Sciences, Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia. Electronic address: mstanic@imsi.rs.
authors.forename: Marina
authors.initials: M
authors.lastname: Stanić
authors.affiliation: Department of Life Sciences, Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia. Electronic address: mzizic@imsi.rs.
authors.forename: Milan
authors.initials: M
authors.lastname: Žižić
authors.affiliation: NMR Laboratory, Institute of General and Physical Chemistry, Studentski trg 12-16, 11000 Belgrade, Serbia. Electronic address: jzakrzewska@iofh.bg.ac.rs.
authors.forename: Joanna
authors.initials: J
authors.lastname: Zakrzewska
authors.affiliation: Institute of Physiology and Biochemistry, University of Belgrade -Faculty of Biology, Studentski trg 16, 11000 Belgrade, Serbia. Electronic address: mzivic@bio.bg.ac.rs.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Živić
authors.affiliation: Department of Neurophysiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia. Electronic address: nara@ibiss.bg.ac.rs.
authors.forename: Nataša
authors.initials: N
authors.lastname: Todorović
mesh_terms: D000873:Anthracenes / Q000494:pharmacology; D002462:Cell Membrane / Q000502:physiology*; D015640:Ion Channel Gating; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials; D009997:Osmotic Pressure; D018408:Patch-Clamp Techniques; D010800:Phycomyces / Q000502:physiology*
chemical_list: D000873:Anthracenes; D007473:Ion Channels; C010030:9-anthroic acid
keywords: A-9-C; Filamentous fungi; Outward rectifier; Voltage-dependent inactivation; Whole-cell patch-clamp