+Open data
-Basic information
Entry | Database: PDB / ID: 7tcp | ||||||
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Title | Structure of Xenopus KCNQ1-CaM | ||||||
Components |
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Keywords | TRANSPORT PROTEIN / ion channel | ||||||
Function / homology | Function and homology information regulation of gastric acid secretion / membrane repolarization / delayed rectifier potassium channel activity / outward rectifier potassium channel activity / CaM pathway / Cam-PDE 1 activation / intestinal absorption / Sodium/Calcium exchangers / Calmodulin induced events / Reduction of cytosolic Ca++ levels ...regulation of gastric acid secretion / membrane repolarization / delayed rectifier potassium channel activity / outward rectifier potassium channel activity / CaM pathway / Cam-PDE 1 activation / intestinal absorption / Sodium/Calcium exchangers / Calmodulin induced events / Reduction of cytosolic Ca++ levels / Activation of Ca-permeable Kainate Receptor / CREB1 phosphorylation through the activation of CaMKII/CaMKK/CaMKIV cascasde / Loss of phosphorylation of MECP2 at T308 / CREB1 phosphorylation through the activation of Adenylate Cyclase / PKA activation / negative regulation of high voltage-gated calcium channel activity / monoatomic ion channel complex / CaMK IV-mediated phosphorylation of CREB / Glycogen breakdown (glycogenolysis) / negative regulation of calcium ion export across plasma membrane / organelle localization by membrane tethering / Activation of RAC1 downstream of NMDARs / regulation of cardiac muscle cell action potential / mitochondrion-endoplasmic reticulum membrane tethering / CLEC7A (Dectin-1) induces NFAT activation / autophagosome membrane docking / renal absorption / positive regulation of ryanodine-sensitive calcium-release channel activity / Negative regulation of NMDA receptor-mediated neuronal transmission / regulation of cell communication by electrical coupling involved in cardiac conduction / Unblocking of NMDA receptors, glutamate binding and activation / negative regulation of peptidyl-threonine phosphorylation / Synthesis of IP3 and IP4 in the cytosol / Phase 0 - rapid depolarisation / protein phosphatase activator activity / RHO GTPases activate PAKs / voltage-gated potassium channel activity / inner ear development / positive regulation of cyclic-nucleotide phosphodiesterase activity / positive regulation of phosphoprotein phosphatase activity / Long-term potentiation / Ion transport by P-type ATPases / Uptake and function of anthrax toxins / Calcineurin activates NFAT / Regulation of MECP2 expression and activity / catalytic complex / DARPP-32 events / detection of calcium ion / Smooth Muscle Contraction / negative regulation of ryanodine-sensitive calcium-release channel activity / RHO GTPases activate IQGAPs / cellular response to interferon-beta / regulation of cardiac muscle contraction / calcium channel inhibitor activity / regulation of cardiac muscle contraction by regulation of the release of sequestered calcium ion / Protein methylation / voltage-gated potassium channel complex / Activation of AMPK downstream of NMDARs / eNOS activation / regulation of release of sequestered calcium ion into cytosol by sarcoplasmic reticulum / regulation of calcium-mediated signaling / positive regulation of protein dephosphorylation / titin binding / regulation of ryanodine-sensitive calcium-release channel activity / Tetrahydrobiopterin (BH4) synthesis, recycling, salvage and regulation / Ion homeostasis / positive regulation of protein autophosphorylation / sperm midpiece / phosphatidylinositol-4,5-bisphosphate binding / calcium channel complex / substantia nigra development / adenylate cyclase activator activity / Ras activation upon Ca2+ influx through NMDA receptor / regulation of heart rate / protein serine/threonine kinase activator activity / sarcomere / FCERI mediated Ca+2 mobilization / FCGR3A-mediated IL10 synthesis / VEGFR2 mediated vascular permeability / positive regulation of peptidyl-threonine phosphorylation / Antigen activates B Cell Receptor (BCR) leading to generation of second messengers / VEGFR2 mediated cell proliferation / regulation of cytokinesis / Translocation of SLC2A4 (GLUT4) to the plasma membrane / spindle microtubule / RAF activation / positive regulation of receptor signaling pathway via JAK-STAT / Transcriptional activation of mitochondrial biogenesis / cytoplasmic vesicle membrane / positive regulation of protein serine/threonine kinase activity / Stimuli-sensing channels / spindle pole / cellular response to type II interferon / response to calcium ion / RAS processing / calcium-dependent protein binding / Inactivation, recovery and regulation of the phototransduction cascade / Signaling by RAF1 mutants / Signaling by moderate kinase activity BRAF mutants / Paradoxical activation of RAF signaling by kinase inactive BRAF Similarity search - Function | ||||||
Biological species | Xenopus laevis (African clawed frog) Homo sapiens (human) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.84 Å | ||||||
Authors | Willegems, K. / Kyriakis, E. / Van Petegem, F. / Eldstrom, J. / Fedida, D. | ||||||
Funding support | Canada, 1items
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Citation | Journal: Nat Commun / Year: 2022 Title: Structural and electrophysiological basis for the modulation of KCNQ1 channel currents by ML277. Authors: Katrien Willegems / Jodene Eldstrom / Efthimios Kyriakis / Fariba Ataei / Harutyun Sahakyan / Ying Dou / Sophia Russo / Filip Van Petegem / David Fedida / Abstract: The KCNQ1 ion channel plays critical physiological roles in electrical excitability and K recycling in organs including the heart, brain, and gut. Loss of function is relatively common and can cause ...The KCNQ1 ion channel plays critical physiological roles in electrical excitability and K recycling in organs including the heart, brain, and gut. Loss of function is relatively common and can cause sudden arrhythmic death, sudden infant death, epilepsy and deafness. Here, we report cryogenic electron microscopic (cryo-EM) structures of Xenopus KCNQ1 bound to Ca/Calmodulin, with and without the KCNQ1 channel activator, ML277. A single binding site for ML277 was identified, localized to a pocket lined by the S4-S5 linker, S5 and S6 helices of two separate subunits. Several pocket residues are not conserved in other KCNQ isoforms, explaining specificity. MD simulations and point mutations support this binding location for ML277 in open and closed channels and reveal that prevention of inactivation is an important component of the activator effect. Our work provides direction for therapeutic intervention targeting KCNQ1 loss of function pathologies including long QT interval syndrome and seizures. | ||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 7tcp.cif.gz | 342.3 KB | Display | PDBx/mmCIF format |
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PDB format | pdb7tcp.ent.gz | 272.3 KB | Display | PDB format |
PDBx/mmJSON format | 7tcp.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/tc/7tcp ftp://data.pdbj.org/pub/pdb/validation_reports/tc/7tcp | HTTPS FTP |
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-Related structure data
Related structure data | 25816MC 7tciC M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 62663.398 Da / Num. of mol.: 4 / Fragment: UNP residues 67-610 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Xenopus laevis (African clawed frog) / Gene: kcnq1, kvlqt1 / Cell line (production host): HEK293 / Production host: Homo sapiens (human) / References: UniProt: P70057 #2: Protein | Mass: 16852.545 Da / Num. of mol.: 4 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: CALM1, CALM, CAM, CAM1 / Cell line (production host): HEK293 / Production host: Homo sapiens (human) / References: UniProt: P0DP23 #3: Chemical | ChemComp-CA / Has ligand of interest | N | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
-Sample preparation
Component | Name: Potassium voltage-gated channel subfamily KQT member 1 in complex with calmodulin Type: COMPLEX / Entity ID: #1-#2 / Source: MULTIPLE SOURCES | |||||||||||||||||||||||||||||||||||
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Molecular weight | Value: 0.31756 MDa / Experimental value: NO | |||||||||||||||||||||||||||||||||||
Source (natural) | Organism: Xenopus laevis (African clawed frog) | |||||||||||||||||||||||||||||||||||
Source (recombinant) | Organism: Homo sapiens (human) / Cell: HEK293 | |||||||||||||||||||||||||||||||||||
Buffer solution | pH: 7.2 | |||||||||||||||||||||||||||||||||||
Buffer component |
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Specimen | Conc.: 2 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | |||||||||||||||||||||||||||||||||||
Specimen support | Grid material: COPPER / Grid mesh size: 400 divisions/in. / Grid type: Quantifoil R1.2/1.3 | |||||||||||||||||||||||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 98 % / Chamber temperature: 277.15 K |
-Electron microscopy imaging
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELDBright-field microscopy / Nominal defocus max: 4900 nm / Nominal defocus min: 360 nm |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Electron dose: 50 e/Å2 / Detector mode: COUNTING / Film or detector model: FEI FALCON IV (4k x 4k) / Num. of grids imaged: 1 / Num. of real images: 19997 |
-Processing
Software | Name: PHENIX / Version: 1.19.2_4158: / Classification: refinement | ||||||||||||||||||||||||
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EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
Particle selection | Num. of particles selected: 1830000 | ||||||||||||||||||||||||
Symmetry | Point symmetry: C4 (4 fold cyclic) | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.84 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 71241 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
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