Abstract
Genetic mutations of the Cl(-) channel ClC-5 cause Dent's disease in humans. We recently cloned an amphibian ortholog of Xenopus ClC-5 (xClC-5) from the A6 cell line. We now compare the properties and regulation of ClC-5 currents expressed in mammalian (COS-7) cells and Xenopus oocytes. Whole cell currents in COS-7 cells transfected with xClC-5 cDNA had strong outward rectification, Cl(-) > I(-) anion sensitivity, and were inhibited at low pH, similar to previous results in oocytes. In oocytes, antisense xClC-5 cRNA injection had no effect on endogenous membrane currents or the heterologous expression of human ClC-5. Activators of cAMP and protein kinase C inhibitors had no significant effects on ClC-5 currents expressed in either COS-7 cells or oocytes, whereas H-89, a cAMP-dependent protein kinase (PKA) inhibitor, and hydrogen peroxide decreased the currents. We conclude that the basic properties of ClC-5 currents were independent of the host cell type used for expression. In addition, ClC-5 channels may be modulated by PKA and reactive oxygen species.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Anions / metabolism
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Antisense Elements (Genetics)
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Biological Transport / physiology
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COS Cells
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Chloride Channels / genetics*
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Chloride Channels / metabolism*
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Chlorides / metabolism
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Cyclic AMP / metabolism
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Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
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Cyclic AMP-Dependent Protein Kinases / metabolism
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Enzyme Inhibitors / pharmacology
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Gene Expression / drug effects
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Gene Expression / physiology
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Humans
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Hydrogen Peroxide / pharmacology*
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Hydrogen-Ion Concentration
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Isoquinolines / pharmacology
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Kidney Diseases / metabolism
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Membrane Potentials / drug effects
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Membrane Potentials / physiology
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Oocytes / physiology
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Oxidants / pharmacology*
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Patch-Clamp Techniques
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Protein Kinase C / antagonists & inhibitors
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Protein Kinase C / metabolism
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Sulfonamides*
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Transfection
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Xenopus
Substances
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Anions
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Antisense Elements (Genetics)
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CLC-5 chloride channel
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Chloride Channels
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Chlorides
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Enzyme Inhibitors
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Isoquinolines
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Oxidants
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Sulfonamides
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Hydrogen Peroxide
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Cyclic AMP
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Cyclic AMP-Dependent Protein Kinases
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Protein Kinase C
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N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide