Functional studies of the effect of NO donor on human CLCN1 polymorphism/mutants expressed in Xenopus laevis oocytes

• Published in: Biochemical and biophysical research communications Vol. 365; no. 4; pp. 724 - 728
• Main Authors: Lin, Min-Jon, Huang, Ren-Yu, Pan, Huichin, Hsiao, Kuang-Ming
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 25.01.2008
• Subjects: Animals; Cells, Cultured; Chloride Channels - drug effects; Chloride Channels - genetics; Chloride Channels - metabolism; CLCN1 polymorphism; Diethylamines - administration & dosage; Dose-Response Relationship, Drug; Electrophysiology; Human skeletal muscle chloride channel (CLCN1); Humans; Ion Channel Gating - drug effects; Ion Channel Gating - physiology; Mutagenesis, Site-Directed; Nitric Oxide Donors - administration & dosage; NO donor; Oocytes - drug effects; Oocytes - physiology; Polymorphism, Genetic; Structure-Activity Relationship; Xenopus laevis; Human skeletal muscle chloride channel (CLCN1); Electrophysiology; CLCN1 polymorphism; NO donor
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2007.11.029

In this study, we investigated the effect of NO donor, diethylamine/nitric oxide (DEA/NO), on the electrophysiological behavior of human skeletal muscle chloride channel (CLCN1). The wild-type and variants of CLCN1, including one polymorphism (P727L) and four mutants (T631I, D644G, G482R, and S471F), were expressed in Xenopus oocytes and the ionic current was measured by two-electrode voltage-clamp method. Our results revealed that there is no significant difference in the current–voltage relationships and half-voltage values of open probability between wild-type and variants of CLCN1 except for G482R. Application of the DEA–NO (0.1 mM) significantly increases the channel conductance of wild-type, T631I, D644G, and S471F, but not P727L. This indicates that P727L polymorphism causes loss of sensitivity of CLCN1 to the DEA/NO treatment, which could be due to a conformational change caused by proline substitution. The data suggest that the polymorphic changes may affect the function of CLCN1 in response to the treatment of chemical compounds.