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| ==structure of human KCNQ1-KCNE3-CaM complex== | | ==structure of human KCNQ1-KCNE3-CaM complex== |
| <StructureSection load='6v00' size='340' side='right'caption='[[6v00]], [[Resolution|resolution]] 3.10Å' scene=''> | | <SX load='6v00' size='340' side='right' viewer='molstar' caption='[[6v00]], [[Resolution|resolution]] 3.10Å' scene=''> |
| == Structural highlights == | | == Structural highlights == |
| <table><tr><td colspan='2'>[[6v00]] is a 12 chain structure with sequence from [http://en.wikipedia.org/wiki/"anaplasma_argentium"_lignieres_1914 "anaplasma argentium" lignieres 1914] and [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6V00 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6V00 FirstGlance]. <br> | | <table><tr><td colspan='2'>[[6v00]] is a 12 chain structure with sequence from [https://en.wikipedia.org/wiki/Anaplasma_marginale Anaplasma marginale] and [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6V00 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6V00 FirstGlance]. <br> |
| </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr> | | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.1Å</td></tr> |
| <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">KCNQ1, KCNA8, KCNA9, KVLQT1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), CALM1, CALM, CAM, CAM1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), KCNE3 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=770 "Anaplasma argentium" Lignieres 1914])</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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6v00 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6v00 OCA], [http://pdbe.org/6v00 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6v00 RCSB], [http://www.ebi.ac.uk/pdbsum/6v00 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6v00 ProSAT]</span></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=6v00 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6v00 OCA], [https://pdbe.org/6v00 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6v00 RCSB], [https://www.ebi.ac.uk/pdbsum/6v00 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6v00 ProSAT]</span></td></tr> |
| </table> | | </table> |
| == Disease == | | == Disease == |
| [[http://www.uniprot.org/uniprot/KCNQ1_HUMAN KCNQ1_HUMAN]] Defects in KCNQ1 are the cause of long QT syndrome type 1 (LQT1) [MIM:[http://omim.org/entry/192500 192500]]; also known as Romano-Ward syndrome (RWS). Long QT syndromes are heart disorders characterized by a prolonged QT interval on the ECG and polymorphic ventricular arrhythmias. They cause syncope and sudden death in response to exercise or emotional stress. LQT1 inheritance is an autosomal dominant.<ref>PMID:18165683</ref> <ref>PMID:9799083</ref> <ref>PMID:10024302</ref> <ref>PMID:8528244</ref> <ref>PMID:9323054</ref> <ref>PMID:8872472</ref> <ref>PMID:8818942</ref> [:]<ref>PMID:9024139</ref> <ref>PMID:9386136</ref> <ref>PMID:9272155</ref> <ref>PMID:9302275</ref> <ref>PMID:9570196</ref> <ref>PMID:9641694</ref> <ref>PMID:9693036</ref> <ref>PMID:9482580</ref> <ref>PMID:9702906</ref> <ref>PMID:10367071</ref> <ref>PMID:9927399</ref> <ref>PMID:10482963</ref> <ref>PMID:10220144</ref> <ref>PMID:10220146</ref> <ref>PMID:10409658</ref> <ref>PMID:10728423</ref> <ref>PMID:10973849</ref> <ref>PMID:15840476</ref> <ref>PMID:19540844</ref> <ref>PMID:21241800</ref> Defects in KCNQ1 are the cause of Jervell and Lange-Nielsen syndrome type 1 (JLNS1) [MIM:[http://omim.org/entry/220400 220400]]. JLNS1 is an autosomal recessive disorder characterized by congenital deafness, prolongation of the QT interval, syncopal attacks due to ventricular arrhythmias, and a high risk of sudden death.<ref>PMID:10728423</ref> <ref>PMID:9781056</ref> <ref>PMID:10090886</ref> Defects in KCNQ1 are the cause of familial atrial fibrillation type 3 (ATFB3) [MIM:[http://omim.org/entry/607554 607554]]. Atrial fibrillation is a common disorder of cardiac rhythm that is hereditary in a small subgroup of patients. It is characterized by disorganized atrial electrical activity and ineffective atrial contraction promoting blood stasis in the atria and reduces ventricular filling. It can result in palpitations, syncope, thromboembolic stroke, and congestive heart failure.<ref>PMID:12522251</ref> Defects in KCNQ1 are the cause of short QT syndrome type 2 (SQT2) [MIM:[http://omim.org/entry/609621 609621]]. Short QT syndromes are heart disorders characterized by idiopathic persistently and uniformly short QT interval on ECG in the absence of structural heart disease in affected individuals. They cause syncope and sudden death.<ref>PMID:15159330</ref> [[http://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. | | [https://www.uniprot.org/uniprot/KCNE3_HUMAN KCNE3_HUMAN] Brugada syndrome;Hypokalemic periodic paralysis. |
| == Function == | | == Function == |
| [[http://www.uniprot.org/uniprot/KCNQ1_HUMAN KCNQ1_HUMAN]] Probably important in cardiac repolarization. Associates with KCNE1 (MinK) to form the I(Ks) cardiac potassium current. Elicits a rapidly activating, potassium-selective outward current. Muscarinic agonist oxotremorine-M strongly suppresses KCNQ1/KCNE1 current in CHO cells in which cloned KCNQ1/KCNE1 channels were coexpressed with M1 muscarinic receptors. May associate also with KCNE3 (MiRP2) to form the potassium channel that is important for cyclic AMP-stimulated intestinal secretion of chloride ions, which is reduced in cystic fibrosis and pathologically stimulated in cholera and other forms of secretory diarrhea. [[http://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> | | [https://www.uniprot.org/uniprot/X5DSL3_ANAMA X5DSL3_ANAMA] [https://www.uniprot.org/uniprot/KCNE3_HUMAN KCNE3_HUMAN] Ancillary protein that assembles as a beta subunit with a voltage-gated potassium channel complex of pore-forming alpha subunits. Modulates the gating kinetics and enhances stability of the channel complex. Assembled with KCNB1 modulates the gating characteristics of the delayed rectifier voltage-dependent potassium channel KCNB1 (PubMed:12954870). Associated with KCNC4/Kv3.4 is proposed to form the subthreshold voltage-gated potassium channel in skeletal muscle and to establish the resting membrane potential (RMP) in muscle cells. Associated with KCNQ1/KCLQT1 may form the intestinal cAMP-stimulated potassium channel involved in chloride secretion that produces a current with nearly instantaneous activation with a linear current-voltage relationship.[UniProtKB:Q9JJV7]<ref>PMID:10646604</ref> <ref>PMID:12954870</ref> |
| <div style="background-color:#fffaf0;">
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| == Publication Abstract from PubMed ==
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| KCNQ1, also known as Kv7.1, is a voltage-dependent K(+) channel that regulates gastric acid secretion, salt and glucose homeostasis, and heart rhythm. Its functional properties are regulated in a tissue-specific manner through co-assembly with beta subunits KCNE1-5. In non-excitable cells, KCNQ1 forms a complex with KCNE3, which suppresses channel closure at negative membrane voltages that otherwise would close it. Pore opening is regulated by the signaling lipid PIP2. Using cryoelectron microscopy (cryo-EM), we show that KCNE3 tucks its single-membrane-spanning helix against KCNQ1, at a location that appears to lock the voltage sensor in its depolarized conformation. Without PIP2, the pore remains closed. Upon addition, PIP2 occupies a site on KCNQ1 within the inner membrane leaflet, which triggers a large conformational change that leads to dilation of the pore's gate. It is likely that this mechanism of PIP2 activation is conserved among Kv7 channels.
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| Structural Basis of Human KCNQ1 Modulation and Gating.,Sun J, MacKinnon R Cell. 2020 Jan 23;180(2):340-347.e9. doi: 10.1016/j.cell.2019.12.003. Epub 2019, Dec 26. PMID:31883792<ref>PMID:31883792</ref>
| | ==See Also== |
| | | *[[Calmodulin 3D structures|Calmodulin 3D structures]] |
| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
| | *[[Green Fluorescent Protein 3D structures|Green Fluorescent Protein 3D structures]] |
| </div>
| | *[[Potassium channel 3D structures|Potassium channel 3D structures]] |
| <div class="pdbe-citations 6v00" style="background-color:#fffaf0;"></div>
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| == References == | | == References == |
| <references/> | | <references/> |
| __TOC__ | | __TOC__ |
| </StructureSection> | | </SX> |
| [[Category: Anaplasma argentium lignieres 1914]] | | [[Category: Anaplasma marginale]] |
| [[Category: Human]] | | [[Category: Homo sapiens]] |
| [[Category: Large Structures]] | | [[Category: Large Structures]] |
| [[Category: Mackinnon, R]] | | [[Category: Mackinnon R]] |
| [[Category: Sun, J]] | | [[Category: Sun J]] |
| [[Category: Cam]]
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| [[Category: Kcnq1]]
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| [[Category: Membrane protein]]
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| [[Category: Potassium channel]]
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