title: Expression and regulation of ClC-5 chloride channels: effects of antisense and oxidants.
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.
authors.affiliation: Department of Physiology and Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA.
authors.forename: T X
authors.initials: TX
authors.lastname: Weng
authors.forename: L
authors.initials: L
authors.lastname: Mo
authors.forename: H L
authors.initials: HL
authors.lastname: Hellmich
authors.forename: A S
authors.initials: AS
authors.lastname: Yu
authors.forename: T
authors.initials: T
authors.lastname: Wood
authors.forename: N K
authors.initials: NK
authors.lastname: Wills
mesh_terms: D000818:Animals; D000838:Anions / Q000378:metabolism; D016375:Antisense Elements (Genetics); D001692:Biological Transport / Q000502:physiology; D019556:COS Cells; D018118:Chloride Channels / Q000235:genetics* / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007546:Isoquinolines / Q000494:pharmacology; D007674:Kidney Diseases / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009865:Oocytes / Q000502:physiology; D016877:Oxidants / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D013449:Sulfonamides; D014162:Transfection; D014981:Xenopus
chemical_list: D000838:Anions; D016375:Antisense Elements (Genetics); C097503:CLC-5 chloride channel; D018118:Chloride Channels; D002712:Chlorides; D004791:Enzyme Inhibitors; D007546:Isoquinolines; D016877:Oxidants; D013449:Sulfonamides; D006861:Hydrogen Peroxide; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide