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Expression of TRPC3 in Chinese Hamster Ovary Cells Results in Calcium-activated Cation Currents Not Related to Store Depletion

TRPC3 (or Htrp3) is a human member of the trp family of Ca(2+)-permeable cation channels. Since expression of TRPC3 cDNA results in markedly enhanced Ca(2+) influx in response to stimulation of membrane receptors linked to phospholipase C (Zhu, X., J. Meisheng, M. Peyton, G. Bouley, R. Hurst, E. Ste...

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Detalles Bibliográficos
Autores principales: Zitt, Christof, Obukhov, Alexander G., Strübing, Carsten, Zobel, Andrea, Kalkbrenner, Frank, Lückhoff, Andreas, Schultz, Günter
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1997
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2132548/
https://www.ncbi.nlm.nih.gov/pubmed/9298988
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author Zitt, Christof
Obukhov, Alexander G.
Strübing, Carsten
Zobel, Andrea
Kalkbrenner, Frank
Lückhoff, Andreas
Schultz, Günter
author_facet Zitt, Christof
Obukhov, Alexander G.
Strübing, Carsten
Zobel, Andrea
Kalkbrenner, Frank
Lückhoff, Andreas
Schultz, Günter
author_sort Zitt, Christof
collection PubMed
description TRPC3 (or Htrp3) is a human member of the trp family of Ca(2+)-permeable cation channels. Since expression of TRPC3 cDNA results in markedly enhanced Ca(2+) influx in response to stimulation of membrane receptors linked to phospholipase C (Zhu, X., J. Meisheng, M. Peyton, G. Bouley, R. Hurst, E. Stefani, and L. Birnbaumer. 1996. Cell. 85:661–671), we tested whether TRPC3 might represent a Ca(2+) entry pathway activated as a consequence of depletion of intracellular calcium stores. CHO cells expressing TRPC3 after intranuclear injection of cDNA coding for TRPC3 were identified by fluorescence from green fluorescent protein. Expression of TRPC3 produced cation currents with little selectivity for Ca(2+) over Na(+). These currents were constitutively active, not enhanced by depletion of calcium stores with inositol-1,4,5-trisphosphate or thapsigargin, and attenuated by strong intracellular Ca(2+) buffering. Ionomycin led to profound increases of currents, but this effect was strictly dependent on the presence of extracellular Ca(2+). Likewise, infusion of Ca(2+) into cell through the patch pipette increased TRPC3 currents. Therefore, TRPC3 is stimulated by a Ca(2+)-dependent mechanism. Studies on TRPC3 in inside-out patches showed cation-selective channels with 60-pS conductance and short (<2 ms) mean open times. Application of ionomycin to cells increased channel activity in cell-attached patches. Increasing the Ca(2+) concentration on the cytosolic side of inside-out patches (from 0 to 1 and 30 μM), however, failed to stimulate channel activity, even in the presence of calmodulin (0.2 μM). We conclude that TRPC3 codes for a Ca(2+)-permeable channel that supports Ca(2+)-induced Ca(2+)-entry but should not be considered store operated.
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spelling pubmed-21325482008-05-01 Expression of TRPC3 in Chinese Hamster Ovary Cells Results in Calcium-activated Cation Currents Not Related to Store Depletion Zitt, Christof Obukhov, Alexander G. Strübing, Carsten Zobel, Andrea Kalkbrenner, Frank Lückhoff, Andreas Schultz, Günter J Cell Biol Article TRPC3 (or Htrp3) is a human member of the trp family of Ca(2+)-permeable cation channels. Since expression of TRPC3 cDNA results in markedly enhanced Ca(2+) influx in response to stimulation of membrane receptors linked to phospholipase C (Zhu, X., J. Meisheng, M. Peyton, G. Bouley, R. Hurst, E. Stefani, and L. Birnbaumer. 1996. Cell. 85:661–671), we tested whether TRPC3 might represent a Ca(2+) entry pathway activated as a consequence of depletion of intracellular calcium stores. CHO cells expressing TRPC3 after intranuclear injection of cDNA coding for TRPC3 were identified by fluorescence from green fluorescent protein. Expression of TRPC3 produced cation currents with little selectivity for Ca(2+) over Na(+). These currents were constitutively active, not enhanced by depletion of calcium stores with inositol-1,4,5-trisphosphate or thapsigargin, and attenuated by strong intracellular Ca(2+) buffering. Ionomycin led to profound increases of currents, but this effect was strictly dependent on the presence of extracellular Ca(2+). Likewise, infusion of Ca(2+) into cell through the patch pipette increased TRPC3 currents. Therefore, TRPC3 is stimulated by a Ca(2+)-dependent mechanism. Studies on TRPC3 in inside-out patches showed cation-selective channels with 60-pS conductance and short (<2 ms) mean open times. Application of ionomycin to cells increased channel activity in cell-attached patches. Increasing the Ca(2+) concentration on the cytosolic side of inside-out patches (from 0 to 1 and 30 μM), however, failed to stimulate channel activity, even in the presence of calmodulin (0.2 μM). We conclude that TRPC3 codes for a Ca(2+)-permeable channel that supports Ca(2+)-induced Ca(2+)-entry but should not be considered store operated. The Rockefeller University Press 1997-09-22 /pmc/articles/PMC2132548/ /pubmed/9298988 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Article
Zitt, Christof
Obukhov, Alexander G.
Strübing, Carsten
Zobel, Andrea
Kalkbrenner, Frank
Lückhoff, Andreas
Schultz, Günter
Expression of TRPC3 in Chinese Hamster Ovary Cells Results in Calcium-activated Cation Currents Not Related to Store Depletion
title Expression of TRPC3 in Chinese Hamster Ovary Cells Results in Calcium-activated Cation Currents Not Related to Store Depletion
title_full Expression of TRPC3 in Chinese Hamster Ovary Cells Results in Calcium-activated Cation Currents Not Related to Store Depletion
title_fullStr Expression of TRPC3 in Chinese Hamster Ovary Cells Results in Calcium-activated Cation Currents Not Related to Store Depletion
title_full_unstemmed Expression of TRPC3 in Chinese Hamster Ovary Cells Results in Calcium-activated Cation Currents Not Related to Store Depletion
title_short Expression of TRPC3 in Chinese Hamster Ovary Cells Results in Calcium-activated Cation Currents Not Related to Store Depletion
title_sort expression of trpc3 in chinese hamster ovary cells results in calcium-activated cation currents not related to store depletion
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2132548/
https://www.ncbi.nlm.nih.gov/pubmed/9298988
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