| Structural highlights
Disease
[CALM1_HUMAN] The disease is caused by mutations affecting the gene represented in this entry. Mutations in CALM1 are the cause of CPVT4. The disease is caused by mutations affecting the gene represented in this entry. Mutations in CALM1 are the cause of LQT14.
Function
[CALM1_HUMAN] Calmodulin mediates the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis (PubMed:16760425). Mediates calcium-dependent inactivation of CACNA1C (PubMed:26969752). Positively regulates calcium-activated potassium channel activity of KCNN2 (PubMed:27165696).[1] [2] [3] [4]
Publication Abstract from PubMed
The Kv7.2 (KCNQ2) channel is the principal molecular component of the slow voltage-gated, noninactivating K(+) M-current, a key controller of neuronal excitability. To investigate the calmodulin (CaM)-mediated Ca(2+) gating of the channel, we used NMR spectroscopy to structurally and dynamically describe the association of helices hA and hB of Kv7.2 with CaM, as a function of Ca(2+) concentration. The structures of the CaM/Kv7.2-hAB complex at two different calcification states are reported here. In the presence of a basal cytosolic Ca(2+) concentration (10-100 nM), only the N-lobe of CaM is Ca(2+)-loaded and the complex (representative of the open channel) exhibits collective dynamics on the millisecond time scale toward a low-populated excited state (1.5%) that corresponds to the inactive state of the channel. In response to a chemical or electrical signal, intracellular Ca(2+) levels rise up to 1-10 muM, triggering Ca(2+) association with the C-lobe. The associated conformational rearrangement is the key biological signal that shifts populations to the closed/inactive channel. This reorientation affects the C-lobe of CaM and both helices in Kv7.2, allosterically transducing the information from the Ca(2+)-binding site to the transmembrane region of the channel.
Structural basis and energy landscape for the Ca(2+) gating and calmodulation of the Kv7.2 K(+) channel.,Bernardo-Seisdedos G, Nunez E, Gomis C, Malo C, Villarroel A, Millet O Proc Natl Acad Sci U S A. 2018 Mar 6;115(10):2395-2400. doi:, 10.1073/pnas.1800235115. Epub 2018 Feb 20. PMID:29463698[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Tsang WY, Spektor A, Luciano DJ, Indjeian VB, Chen Z, Salisbury JL, Sanchez I, Dynlacht BD. CP110 cooperates with two calcium-binding proteins to regulate cytokinesis and genome stability. Mol Biol Cell. 2006 Aug;17(8):3423-34. Epub 2006 Jun 7. PMID:16760425 doi:10.1091/mbc.E06-04-0371
- ↑ Reichow SL, Clemens DM, Freites JA, Nemeth-Cahalan KL, Heyden M, Tobias DJ, Hall JE, Gonen T. Allosteric mechanism of water-channel gating by Ca-calmodulin. Nat Struct Mol Biol. 2013 Jul 28. doi: 10.1038/nsmb.2630. PMID:23893133 doi:10.1038/nsmb.2630
- ↑ Boczek NJ, Gomez-Hurtado N, Ye D, Calvert ML, Tester DJ, Kryshtal D, Hwang HS, Johnson CN, Chazin WJ, Loporcaro CG, Shah M, Papez AL, Lau YR, Kanter R, Knollmann BC, Ackerman MJ. Spectrum and Prevalence of CALM1-, CALM2-, and CALM3-Encoded Calmodulin Variants in Long QT Syndrome and Functional Characterization of a Novel Long QT Syndrome-Associated Calmodulin Missense Variant, E141G. Circ Cardiovasc Genet. 2016 Apr;9(2):136-146. doi:, 10.1161/CIRCGENETICS.115.001323. Epub 2016 Mar 11. PMID:26969752 doi:http://dx.doi.org/10.1161/CIRCGENETICS.115.001323
- ↑ Yu CC, Ko JS, Ai T, Tsai WC, Chen Z, Rubart M, Vatta M, Everett TH 4th, George AL Jr, Chen PS. Arrhythmogenic calmodulin mutations impede activation of small-conductance calcium-activated potassium current. Heart Rhythm. 2016 Aug;13(8):1716-23. doi: 10.1016/j.hrthm.2016.05.009. Epub 2016, May 7. PMID:27165696 doi:http://dx.doi.org/10.1016/j.hrthm.2016.05.009
- ↑ Bernardo-Seisdedos G, Nunez E, Gomis C, Malo C, Villarroel A, Millet O. Structural basis and energy landscape for the Ca(2+) gating and calmodulation of the Kv7.2 K(+) channel. Proc Natl Acad Sci U S A. 2018 Mar 6;115(10):2395-2400. doi:, 10.1073/pnas.1800235115. Epub 2018 Feb 20. PMID:29463698 doi:http://dx.doi.org/10.1073/pnas.1800235115
|
