Ionic channels in the plasma membrane of Schizosaccharomyces pombe: evidence from patch-clamp measurements.
Patch-clamp studies of the yeast Schizosaccharomyces pombe reveal that the plasma membrane contains a voltage-gated channel mildly selective for potassium over sodium, lithium, and chloride. The channel exhibits several conductances with a maximum of 153 pS. The channel gates in the region of physiologically relevant voltages, being closed at hyperpolarizing and open at depolarizing voltages. It is not inhibited by tetraethylammonium, quinine, or quinidine applied from the cytoplasmic side of the membrane; similarly, ATP and stretch have no effect. The frequency of its occurrence in patches implies that about 35 channels of this kind are present in the plasma membrane of a single cell.
Vacata
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Botanisches Institut, Universität Bonn, Germany.
Höfer
M
M
Larsson
H P
HP
Lecar
H
H
D000255:Adenosine Triphosphate / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D004553:Electric Conductivity; D015640:Ion Channel Gating; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism*; D015221:Potassium Channels / Q000378:metabolism; D012568:Schizosaccharomyces / Q000378:metabolism*; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology
D007473:Ion Channels; D015221:Potassium Channels; D013757:Tetraethylammonium Compounds; D019789:Tetraethylammonium; D000255:Adenosine Triphosphate