| Structural highlights
Disease
[CLCN1_HUMAN] Thomsen and Becker disease. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry.
Function
[CLCN1_HUMAN] Voltage-gated chloride channel. Chloride channels have several functions including the regulation of cell volume; membrane potential stabilization, signal transduction and transepithelial transport.[1] [2] [3] [4] [5] [6] [7] [8] [9]
Publication Abstract from PubMed
CLC channels mediate passive Cl(-) conduction, while CLC transporters mediate active Cl(-) transport coupled to H(+) transport in the opposite direction. The distinction between CLC-0/1/2 channels and CLC transporters seems undetectable by amino acid sequence. To understand why they are different functionally we determined the structure of the human CLC-1 channel. Its 'glutamate gate' residue, known to mediate proton transfer in CLC transporters, adopts a location in the structure that appears to preclude it from its transport function. Furthermore, smaller side chains produce a wider pore near the intracellular surface, potentially reducing a kinetic barrier for Cl(-) conduction. When the corresponding residues are mutated in a transporter, it is converted to a channel. Finally, Cl(-) at key sites in the pore appear to interact with reduced affinity compared to transporters. Thus, subtle differences in glutamate gate conformation, internal pore diameter and Cl(-) affinity distinguish CLC channels and transporters.
Structure of the CLC-1 chloride channel from Homo sapiens.,Park E, MacKinnon R Elife. 2018 May 29;7. pii: 36629. doi: 10.7554/eLife.36629. PMID:29809153[10]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Ryan A, Rudel R, Kuchenbecker M, Fahlke C. A novel alteration of muscle chloride channel gating in myotonia levior. J Physiol. 2002 Dec 1;545(Pt 2):345-54. PMID:12456816
- ↑ Ulzi G, Lecchi M, Sansone V, Redaelli E, Corti E, Saccomanno D, Pagliarani S, Corti S, Magri F, Raimondi M, D'Angelo G, Modoni A, Bresolin N, Meola G, Wanke E, Comi GP, Lucchiari S. Myotonia congenita: novel mutations in CLCN1 gene and functional characterizations in Italian patients. J Neurol Sci. 2012 Jul 15;318(1-2):65-71. doi: 10.1016/j.jns.2012.03.024. Epub, 2012 Apr 21. PMID:22521272 doi:https://dx.doi.org/10.1016/j.jns.2012.03.024
- ↑ Portaro S, Altamura C, Licata N, Camerino GM, Imbrici P, Musumeci O, Rodolico C, Conte Camerino D, Toscano A, Desaphy JF. Clinical, Molecular, and Functional Characterization of CLCN1 Mutations in Three Families with Recessive Myotonia Congenita. Neuromolecular Med. 2015 Sep;17(3):285-96. doi: 10.1007/s12017-015-8356-8. Epub, 2015 May 26. PMID:26007199 doi:https://dx.doi.org/10.1007/s12017-015-8356-8
- ↑ Ronstedt K, Sternberg D, Detro-Dassen S, Gramkow T, Begemann B, Becher T, Kilian P, Grieschat M, Machtens JP, Schmalzing G, Fischer M, Fahlke C. Impaired surface membrane insertion of homo- and heterodimeric human muscle chloride channels carrying amino-terminal myotonia-causing mutations. Sci Rep. 2015 Oct 27;5:15382. doi: 10.1038/srep15382. PMID:26502825 doi:https://dx.doi.org/10.1038/srep15382
- ↑ Vindas-Smith R, Fiore M, Vasquez M, Cuenca P, Del Valle G, Lagostena L, Gaitan-Penas H, Estevez R, Pusch M, Morales F. Identification and Functional Characterization of CLCN1 Mutations Found in Nondystrophic Myotonia Patients. Hum Mutat. 2016 Jan;37(1):74-83. doi: 10.1002/humu.22916. Epub 2015 Oct 28. PMID:26510092 doi:https://dx.doi.org/10.1002/humu.22916
- ↑ Lorenz C, Meyer-Kleine C, Steinmeyer K, Koch MC, Jentsch TJ. Genomic organization of the human muscle chloride channel CIC-1 and analysis of novel mutations leading to Becker-type myotonia. Hum Mol Genet. 1994 Jun;3(6):941-6. PMID:7951242
- ↑ Steinmeyer K, Lorenz C, Pusch M, Koch MC, Jentsch TJ. Multimeric structure of ClC-1 chloride channel revealed by mutations in dominant myotonia congenita (Thomsen). EMBO J. 1994 Feb 15;13(4):737-43. PMID:8112288
- ↑ Fahlke C, Beck CL, George AL Jr. A mutation in autosomal dominant myotonia congenita affects pore properties of the muscle chloride channel. Proc Natl Acad Sci U S A. 1997 Mar 18;94(6):2729-34. PMID:9122265
- ↑ Kubisch C, Schmidt-Rose T, Fontaine B, Bretag AH, Jentsch TJ. ClC-1 chloride channel mutations in myotonia congenita: variable penetrance of mutations shifting the voltage dependence. Hum Mol Genet. 1998 Oct;7(11):1753-60. PMID:9736777
- ↑ Park E, MacKinnon R. Structure of the CLC-1 chloride channel from Homo sapiens. Elife. 2018 May 29;7. pii: 36629. doi: 10.7554/eLife.36629. PMID:29809153 doi:https://dx.doi.org/10.7554/eLife.36629
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