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| - | {{STRUCTURE_3oxq| PDB=3oxq | SCENE= }} | |
| - | ===Crystal Structure of Ca2+/CaM-CaV1.2 pre-IQ/IQ domain complex=== | |
| - | {{ABSTRACT_PUBMED_20953164}} | |
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| - | ==Disease== | + | ==Crystal Structure of Ca2+/CaM-CaV1.2 pre-IQ/IQ domain complex== |
| - | [[http://www.uniprot.org/uniprot/CAC1C_HUMAN CAC1C_HUMAN]] Defects in CACNA1C are the cause of Timothy syndrome (TS) [MIM:[http://omim.org/entry/601005 601005]]. TS is a disorder characterized by multiorgan dysfunction including lethal arrhythmias, webbing of fingers and toes, congenital heart disease, immune deficiency, intermittent hypoglycemia, cognitive abnormalities and autism.<ref>PMID:15454078</ref><ref>PMID:15863612</ref> Defects in CACNA1C are the cause of Brugada syndrome type 3 (BRGDA3) [MIM:[http://omim.org/entry/611875 611875]]. A heart disease characterized by the association of Brugada syndrome with shortened QT intervals. Brugada syndrome is a tachyarrhythmia characterized by right bundle branch block and ST segment elevation on an electrocardiogram (ECG). It can cause the ventricles to beat so fast that the blood is prevented from circulating efficiently in the body. When this situation occurs (called ventricular fibrillation), the individual will faint and may die in a few minutes if the heart is not reset.<ref>PMID:17224476</ref> | + | <StructureSection load='3oxq' size='340' side='right'caption='[[3oxq]], [[Resolution|resolution]] 2.55Å' scene=''> |
| | + | == Structural highlights == |
| | + | <table><tr><td colspan='2'>[[3oxq]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3OXQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3OXQ FirstGlance]. <br> |
| | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.55Å</td></tr> |
| | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr> |
| | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3oxq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3oxq OCA], [https://pdbe.org/3oxq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3oxq RCSB], [https://www.ebi.ac.uk/pdbsum/3oxq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3oxq ProSAT]</span></td></tr> |
| | + | </table> |
| | + | == Disease == |
| | + | [https://www.uniprot.org/uniprot/CALM1_HUMAN 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 == |
| | + | [https://www.uniprot.org/uniprot/CALM1_HUMAN 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).<ref>PMID:16760425</ref> <ref>PMID:23893133</ref> <ref>PMID:26969752</ref> <ref>PMID:27165696</ref> |
| | + | <div style="background-color:#fffaf0;"> |
| | + | == Publication Abstract from PubMed == |
| | + | Interactions between voltage-gated calcium channels (Ca(V)s) and calmodulin (CaM) modulate Ca(V) function. In this study, we report the structure of a Ca(2+)/CaM Ca(V)1.2 C-terminal tail complex that contains two PreIQ helices bridged by two Ca(2+)/CaMs and two Ca(2+)/CaM-IQ domain complexes. Sedimentation equilibrium experiments establish that the complex has a 2:1 Ca(2+)/CaM:C-terminal tail stoichiometry and does not form higher order assemblies. Moreover, subunit-counting experiments demonstrate that in live cell membranes Ca(V)1.2s are monomers. Thus, contrary to previous proposals, the crystallographic dimer lacks physiological relevance. Isothermal titration calorimetry and biochemical experiments show that the two Ca(2+)/CaMs in the complex have different properties. Ca(2+)/CaM bound to the PreIQ C-region is labile, whereas Ca(2+)/CaM bound to the IQ domain is not. Furthermore, neither of lobes of apo-CaM interacts strongly with the PreIQ domain. Electrophysiological studies indicate that the PreIQ C-region has a role in calcium-dependent facilitation. Together, the data show that two Ca(2+)/CaMs can bind the Ca(V)1.2 tail simultaneously and indicate a functional role for Ca(2+)/CaM at the C-region site. |
| | | | |
| - | ==Function==
| + | Multiple C-terminal tail Ca(2+)/CaMs regulate Ca(V)1.2 function but do not mediate channel dimerization.,Kim EY, Rumpf CH, Van Petegem F, Arant RJ, Findeisen F, Cooley ES, Isacoff EY, Minor DL Jr EMBO J. 2010 Oct 15. PMID:20953164<ref>PMID:20953164</ref> |
| - | [[http://www.uniprot.org/uniprot/CAC1C_HUMAN CAC1C_HUMAN]] Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The isoform alpha-1C gives rise to L-type calcium currents. Long-lasting (L-type) calcium channels belong to the 'high-voltage activated' (HVA) group. They are blocked by dihydropyridines (DHP), phenylalkylamines, benzothiazepines, and by omega-agatoxin-IIIA (omega-Aga-IIIA). They are however insensitive to omega-conotoxin-GVIA (omega-CTx-GVIA) and omega-agatoxin-IVA (omega-Aga-IVA). Calcium channels containing the alpha-1C subunit play an important role in excitation-contraction coupling in the heart. The various isoforms display marked differences in the sensitivity to DHP compounds. Binding of calmodulin or CABP1 at the same regulatory sites results in an opposit effects on the channel function.<ref>PMID:8392192</ref><ref>PMID:7737988</ref><ref>PMID:9013606</ref><ref>PMID:9607315</ref><ref>PMID:12176756</ref><ref>PMID:17071743</ref>
| + | |
| | | | |
| - | ==About this Structure==
| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| - | [[3oxq]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3OXQ OCA].
| + | </div> |
| | + | <div class="pdbe-citations 3oxq" style="background-color:#fffaf0;"></div> |
| | | | |
| | ==See Also== | | ==See Also== |
| - | *[[Calmodulin|Calmodulin]] | + | *[[Calmodulin 3D structures|Calmodulin 3D structures]] |
| - | *[[Ion channels|Ion channels]] | + | *[[Ion channels 3D structures|Ion channels 3D structures]] |
| - | | + | == References == |
| - | ==Reference== | + | <references/> |
| - | <ref group="xtra">PMID:020953164</ref><references group="xtra"/><references/>
| + | __TOC__ |
| | + | </StructureSection> |
| | [[Category: Homo sapiens]] | | [[Category: Homo sapiens]] |
| - | [[Category: Arant, R.]] | + | [[Category: Large Structures]] |
| - | [[Category: Cooley, E S.]] | + | [[Category: Arant R]] |
| - | [[Category: Findeisen, F.]] | + | [[Category: Cooley ES]] |
| - | [[Category: Isacoff, E Y.]] | + | [[Category: Findeisen F]] |
| - | [[Category: Kim, E Y.]] | + | [[Category: Isacoff EY]] |
| - | [[Category: Minor, D L.]] | + | [[Category: Kim EY]] |
| - | [[Category: Petegem, F Van.]]
| + | [[Category: Minor DL]] |
| - | [[Category: Rumpf, C H.]] | + | [[Category: Rumpf CH]] |
| - | [[Category: Calcium binding]] | + | [[Category: Van Petegem F]] |
| - | [[Category: Calcium sensing]]
| + | |
| - | [[Category: Ef hand iq domain]]
| + | |
| - | [[Category: Ion channel]]
| + | |
| - | [[Category: Metal binding protein-transport protein complex]]
| + | |
| 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
Interactions between voltage-gated calcium channels (Ca(V)s) and calmodulin (CaM) modulate Ca(V) function. In this study, we report the structure of a Ca(2+)/CaM Ca(V)1.2 C-terminal tail complex that contains two PreIQ helices bridged by two Ca(2+)/CaMs and two Ca(2+)/CaM-IQ domain complexes. Sedimentation equilibrium experiments establish that the complex has a 2:1 Ca(2+)/CaM:C-terminal tail stoichiometry and does not form higher order assemblies. Moreover, subunit-counting experiments demonstrate that in live cell membranes Ca(V)1.2s are monomers. Thus, contrary to previous proposals, the crystallographic dimer lacks physiological relevance. Isothermal titration calorimetry and biochemical experiments show that the two Ca(2+)/CaMs in the complex have different properties. Ca(2+)/CaM bound to the PreIQ C-region is labile, whereas Ca(2+)/CaM bound to the IQ domain is not. Furthermore, neither of lobes of apo-CaM interacts strongly with the PreIQ domain. Electrophysiological studies indicate that the PreIQ C-region has a role in calcium-dependent facilitation. Together, the data show that two Ca(2+)/CaMs can bind the Ca(V)1.2 tail simultaneously and indicate a functional role for Ca(2+)/CaM at the C-region site.
Multiple C-terminal tail Ca(2+)/CaMs regulate Ca(V)1.2 function but do not mediate channel dimerization.,Kim EY, Rumpf CH, Van Petegem F, Arant RJ, Findeisen F, Cooley ES, Isacoff EY, Minor DL Jr EMBO J. 2010 Oct 15. PMID:20953164[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
- ↑ Kim EY, Rumpf CH, Van Petegem F, Arant RJ, Findeisen F, Cooley ES, Isacoff EY, Minor DL Jr. Multiple C-terminal tail Ca(2+)/CaMs regulate Ca(V)1.2 function but do not mediate channel dimerization. EMBO J. 2010 Oct 15. PMID:20953164 doi:10.1038/emboj.2010.260
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