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Item Type: | Article |
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Title: | The G215R mutation in the Cl-/H+-antiporter ClC-7 found in ADO II osteopetrosis does not abolish function but causes a severe trafficking defect |
Creators Name: | Schulze, K., Werner, J., Stauber, T., Henriksen, K. and Fendler, K. |
Abstract: | BACKGROUND: ClC-7 is a ubiquitous transporter which is broadly expressed in mammalian tissues. It is implied in the pathogenesis of lysosomal storage disease and osteopetrosis. Because of its endosomal/lysosomal localization it is still poorly characterized. METHODOLOGY/PRINCIPAL FINDINGS: An electrophysiological characterization of rat ClC-7 using solid-supported membrane-based electrophysiology is presented. The measured currents show the characteristics of ClC-7 and confirm its function as a Cl(-)/H(+)-antiporter. We have used rat ClC-7 in CHO cells as a model system to investigate the functionality and cellular localization of the wt transporter and its variant G213R ClC-7 which is the analogue of human G215R ClC-7 responsible for autosomal dominant osteopetrosis type II. Our study shows that rat G213R ClC-7 is functional but has a localization defect in CHO cells which prevents it from being correctly targeted to the lysosomal membrane. The electrophysiological assay is tested as a tool for drug discovery. The assay is validated with a number of drug candidates. It is shown that ClC-7 is inhibited by DIDS, NPPB and NS5818 at micromolar concentrations. CONCLUSIONS/SIGNIFICANCE: It is suggested that the scenario found in the CHO model system also applies to the human transporter and that mislocalization rather than impaired functionality of G215R ClC-7 is the primary cause of the related autosomal dominant osteopetrosis type II. Furthermore, the robust solid-supported membrane-based electrophysiological assay is proposed for rapid screening for potential ClC-7 inhibitors which are discussed for treatment of osteoporosis. |
Keywords: | CHO Cells, Cell Line, Chloride Channels, Lysosomes, Missense Mutation, Osteopetrosis, Protein Transport, Animals, Rats, Cricetinae, Cricetulus |
Source: | PLoS ONE |
ISSN: | 1932-6203 |
Publisher: | Public Library of Science |
Volume: | 5 |
Number: | 9 |
Page Range: | e12585 |
Date: | 7 September 2010 |
Official Publication: | https://doi.org/10.1371/journal.pone.0012585 |
PubMed: | View item in PubMed |
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