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Item Type: | Article |
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Title: | ClC-7 is a slowly voltage-gated 2Cl(-)/1H(+)-exchanger and requires Ostm1 for transport activity |
Creators Name: | Leisle, L., Ludwig, C.F., Wagner, F.A., Jentsch, T.J. and Stauber, T. |
Abstract: | Mutations in the ClC-7/Ostm1 ion transporter lead to osteopetrosis and lysosomal storage disease. Its lysosomal localization hitherto precluded detailed functional characterization. Using a mutated ClC-7 that reaches the plasma membrane, we now show that both the aminoterminus and transmembrane span of the Ostm1 β-subunit are required for ClC-7 Cl(-)/H(+)-exchange, whereas the Ostm1 transmembrane domain suffices for its ClC-7-dependent trafficking to lysosomes. ClC-7/Ostm1 currents were strongly outwardly rectifying owing to slow gating of ion exchange, which itself displays an intrinsically almost linear voltage dependence. Reversal potentials of tail currents revealed a 2Cl(-)/1H(+)-exchange stoichiometry. Several disease-causing CLCN7 mutations accelerated gating. Such mutations cluster to the second cytosolic cystathionine-β-synthase domain and potential contact sites at the transmembrane segment. Our work suggests that gating underlies the rectification of all endosomal/lysosomal CLCs and extends the concept of voltage gating beyond channels to ion exchangers. |
Keywords: | Antiport, Chloride Channel, Conductance, Structure-Function, Trafficking |
Source: | EMBO Journal |
ISSN: | 0261-4189 |
Publisher: | Nature Publishing Group |
Volume: | 30 |
Number: | 11 |
Page Range: | 2140-2152 |
Date: | 1 June 2011 |
Official Publication: | https://doi.org/10.1038/emboj.2011.137 |
PubMed: | View item in PubMed |
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