Oxidation induces ClC-3-dependent anion channels in human leukaemia cells.
To test for redox regulation of anion channels in erythroid cells, we exposed K562 cells to oxidants and measured changes in transmembrane Cl(-) currents using patch-clamp, and in intracellular Cl(-) content using the Cl(-) selective dye MQAE. Oxidation with tert-butylhydroperoxide or H(2)O(2) produced a plasma membrane anion permeability with a permselectivity of NO(3)(-)>lactate(-)>gluconate(-). The permeability increase was paralleled by insertion of ClC-3 protein into the plasma membrane as evident from immunofluorescence microscopy and surface biotinylation. Down-regulation of ClC-3 protein by RNA interference as assessed by immunoblotting decreased the oxidation-stimulated permeability. In conclusion, oxidation induces surface expression of ClC-3 and activation of a ClC-3-dependent anion permeability in K562 cells.
Kasinathan
Ravi S
RS
Department of Physiology I, Eberhard-Karls-University Tübingen, Gmelinstrasse 5, D-72076 Tübingen, Germany.
Föller
Michael
M
Lang
Camelia
C
Koka
Saisudha
S
Lang
Florian
F
Huber
Stephan M
SM
D000838:Anions / Q000737:chemistry; D045744:Cell Line, Tumor; D018118:Chloride Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004594:Electrophysiology; D006801:Humans; D007938:Leukemia / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D018408:Patch-Clamp Techniques; D034741:RNA, Small Interfering / Q000235:genetics
D000838:Anions; D018118:Chloride Channels; C115376:ClC-3 channel; D034741:RNA, Small Interfering