A Novel Cl− Inward-Rectifying Current in the Plasma Membrane of the Calcifying Marine Phytoplankton Coccolithus pelagicus
- 1 March 2003
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 131 (3), 1391-1400
- https://doi.org/10.1104/pp.011791
Abstract
We investigated the membrane properties and dominant ionic conductances in the plasma membrane of the calcifying marine phytoplankton Coccolithus pelagicus using the patch-clamp technique. Whole-cell recordings obtained from decalcified cells revealed a dominant anion conductance in response to membrane hyperpolarization. Ion substitution showed that the anion channels were selective for Cl− and Br− over other anions, and the sensitivity to the stilbene derivative 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid, ethacrynic acid, and Zn2+ revealed a pharmacological profile typical of many plant and animal anion channels. Voltage activation and kinetic characteristics of the C. pelagicusCl− channel are consistent with a novel function in plants as the inward rectifier that tightly regulates membrane potential. Membrane depolarization gave rise to nonselective cation currents and in some cases evoked action potential currents. We propose that these major ion conductances play an essential role in membrane voltage regulation that relates to the unique transport physiology of these calcifying phytoplankton.Keywords
This publication has 39 references indexed in Scilit:
- Control of Cl− Efflux in Chara corallina by Cytosolic pH, Free Ca2+, and Phosphorylation Indicates a Role of Plasma Membrane Anion Channels in Cytosolic pH Regulation1Plant Physiology, 1998
- Anions permeate and gate GCAC1, a voltage‐dependent guard cell anion channelThe Plant Journal, 1998
- Calcium channels in higher plant cells: selectivity, regulation and pharmacologyJournal of Experimental Botany, 1997
- Ion channel activity during the action potential in Chara: new insights with new techniquesJournal of Experimental Botany, 1997
- GCAC1 recognizes the pH gradient across the plasma membrane: a pH‐sensitive and ATP‐dependent anion channel links guard cell membrane potential to acid and energy metabolismThe Plant Journal, 1996
- Spatial Organization of Calcium Signaling Involved in Cell Volume Control in the Fucus RhizoidTHE PLANT CELL ONLINE, 1996
- A Sodium Pump in the Plasma Membrane of the Marine Alga Heterosigma akashiwoPlant and Cell Physiology, 1996
- Coccolithophorid blooms in the global oceanJournal of Geophysical Research: Oceans, 1994
- The photoreceptor current of the green algaChlamydomonasPhilosophical Transactions B, 1992
- Ion channels in the plasma membrane ofAmaranthus protoplasts: One cation and one anion channel dominate the conductanceThe Journal of Membrane Biology, 1991