An optical assay of the transport activity of ClC-7
نویسندگان
چکیده
Osteoporosis, characterized by excessive osteoclast mediated bone resorption, affects millions of people worldwide representing a major public health problem. ClC-7 is a chloride-proton exchanger localized in lysosomes and in the resorption lacuna in osteoclasts where it is essential for bone resorption. Thus, drugs targeted at ClC-7 have been proposed for ameliorating osteoporosis. However, functional assays suited for high throughput screening (HTS) of ClC-7 function are lacking. Here we describe two complementary variants of purely optical assays of the transport activity of ClC-7, redirected to the plasma membrane employing a genetically encoded fluorescent Cl⁻/pH indicator fused to the ClC-7 protein. These simple and robust functional assays of ClC-7 transport are well-suited to be applied in HTS of small-molecule inhibitors and may help to develop drugs suited for the treatment of osteoporosis.
منابع مشابه
Scientific Report Transport activity and presence of ClC-7/Ostm1 complex account for different cellular functions
Loss of the lysosomal ClC-7/Ostm1 2Cl /H exchanger causes lysosomal storage disease and osteopetrosis in humans and additionally changes fur colour in mice. Its conversion into a Cl conductance in Clcn7 mice entails similarly severe lysosomal storage, but less severe osteopetrosis and no change in fur colour. To elucidate the basis for these phenotypical differences, we generated Clcn7 mice exp...
متن کاملTransport activity and presence of ClC-7/Ostm1 complex account for different cellular functions.
Loss of the lysosomal ClC-7/Ostm1 2Cl(-)/H(+) exchanger causes lysosomal storage disease and osteopetrosis in humans and additionally changes fur colour in mice. Its conversion into a Cl(-) conductance in Clcn7(unc/unc) mice entails similarly severe lysosomal storage, but less severe osteopetrosis and no change in fur colour. To elucidate the basis for these phenotypical differences, we generat...
متن کاملLysosomal degradation of endocytosed proteins depends on the chloride transport protein ClC-7.
Mutations in either ClC-7, a late endosomal/lysosomal member of the CLC family of chloride channels and transporters, or in its beta-subunit Ostm1 cause osteopetrosis and lysosomal storage disease in mice and humans. The severe phenotype of mice globally deleted for ClC-7 or Ostm1 and the absence of storage material in cultured cells hampered investigations of the mechanism leading to lysosomal...
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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 electrophysiolo...
متن کاملClC-7 is a slowly voltage-gated 2Cl(-)/1H(+)-exchanger and requires Ostm1 for transport activity.
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 transmembra...
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