Anion, cation, and zwitterion selectivity of phospholemman channel molecules

Gopal C. Kowdley, Stephen J. Ackerman, Zhenhui Chen, Gabor Szabo, Larry R. Jones, J. Randall Moorman

Research output: Contribution to journalArticle

45 Scopus citations

Abstract

Phospholemman (PLM), a 72-amino acid membrane protein with a single transmembrane domain, forms taurine-selective ion channels in lipid bilayers. Because taurine forms zwitterions, a taurine-selective channel might have binding sites for both anions and cations. Here we show that PLM channels indeed allow fluxes of both cations and anions, making instantaneous and voltage-dependent transitions among conformations with drastically different ion selectivity characteristics. This surprising and novel ion channel behavior offers a molecular explanation for selective taurine flux across cell membranes and may explain why molecules in the phospholemman family can induce cation- or anion-selective conductances when expressed in Xenopus oocytes.

Original languageEnglish (US)
Pages (from-to)141-145
Number of pages5
JournalBiophysical journal
Volume72
Issue number1
DOIs
StatePublished - Jan 1997

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ASJC Scopus subject areas

  • Biophysics

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