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Open data
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Basic information
Entry | Database: PDB / ID: 8qko | ||||||
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Title | Connexin-43 gap junction channel in complex with mefloquine | ||||||
![]() | Gap junction alpha-1 protein | ||||||
![]() | MEMBRANE PROTEIN / connexin / gap junction channel / complex / mefloquine | ||||||
Function / homology | ![]() gap junction channel activity involved in cardiac conduction electrical coupling / negative regulation of gonadotropin secretion / positive regulation of striated muscle tissue development / milk ejection reflex / positive regulation of morphogenesis of an epithelium / positive regulation of mesodermal cell differentiation / atrial ventricular junction remodeling / cell communication by chemical coupling / cell communication by electrical coupling / neuroblast migration ...gap junction channel activity involved in cardiac conduction electrical coupling / negative regulation of gonadotropin secretion / positive regulation of striated muscle tissue development / milk ejection reflex / positive regulation of morphogenesis of an epithelium / positive regulation of mesodermal cell differentiation / atrial ventricular junction remodeling / cell communication by chemical coupling / cell communication by electrical coupling / neuroblast migration / columnar/cuboidal epithelial cell maturation / negative regulation of trophoblast cell migration / microtubule-based transport / gap junction hemi-channel activity / monoatomic ion transmembrane transporter activity / regulation of bone remodeling / SARS-CoV-2 targets PDZ proteins in cell-cell junction / gap junction channel activity involved in cell communication by electrical coupling / regulation of ventricular cardiac muscle cell membrane depolarization / contractile muscle fiber / Oligomerization of connexins into connexons / Transport of connexins along the secretory pathway / glutathione transmembrane transporter activity / Microtubule-dependent trafficking of connexons from Golgi to the plasma membrane / gap junction assembly / atrial cardiac muscle cell action potential / Regulation of gap junction activity / cardiac conduction system development / regulation of atrial cardiac muscle cell membrane depolarization / cellular response to pH / connexin complex / fascia adherens / gap junction / cell-cell contact zone / Formation of annular gap junctions / Golgi-associated vesicle membrane / cell communication by electrical coupling involved in cardiac conduction / Gap junction degradation / bone remodeling / skeletal muscle tissue regeneration / gap junction channel activity / Gap junction assembly / regulation of bone mineralization / export across plasma membrane / adult heart development / regulation of ventricular cardiac muscle cell membrane repolarization / tight junction / glutamate secretion / blood vessel morphogenesis / lens development in camera-type eye / intermediate filament / xenobiotic transport / Mechanical load activates signaling by PIEZO1 and integrins in osteocytes / embryonic digit morphogenesis / maintenance of blood-brain barrier / positive regulation of stem cell proliferation / beta-tubulin binding / RHOJ GTPase cycle / RHOQ GTPase cycle / heart looping / establishment of mitotic spindle orientation / efflux transmembrane transporter activity / intercalated disc / alpha-tubulin binding / lateral plasma membrane / T cell proliferation / positive regulation of vascular associated smooth muscle cell proliferation / tubulin binding / protein tyrosine kinase binding / negative regulation of cell growth / beta-catenin binding / bone development / cellular response to amyloid-beta / male gonad development / neuron migration / osteoblast differentiation / cell junction / intracellular protein localization / cell-cell signaling / positive regulation of cold-induced thermogenesis / heart development / scaffold protein binding / monoatomic ion transmembrane transport / spermatogenesis / in utero embryonic development / positive regulation of canonical NF-kappaB signal transduction / apical plasma membrane / membrane raft / Golgi membrane / signaling receptor binding / negative regulation of gene expression / focal adhesion / intracellular membrane-bounded organelle / positive regulation of gene expression / endoplasmic reticulum membrane / Golgi apparatus / signal transduction / mitochondrion / nucleoplasm / nucleus Similarity search - Function | ||||||
Biological species | ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.73 Å | ||||||
![]() | Lavriha, P. / Korkhov, V.M. / Han, Y. | ||||||
Funding support | ![]()
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![]() | ![]() Title: Mechanism of connexin channel inhibition by mefloquine and 2-aminoethoxydiphenyl borate. Authors: Pia Lavriha / Yufei Han / Xinyue Ding / Dina Schuster / Chao Qi / Anand Vaithia / Paola Picotti / Volodymyr M Korkhov / ![]() ![]() Abstract: Gap junction intercellular communication (GJIC) between two adjacent cells involves direct exchange of cytosolic ions and small molecules via connexin gap junction channels (GJCs). Connexin GJCs have ...Gap junction intercellular communication (GJIC) between two adjacent cells involves direct exchange of cytosolic ions and small molecules via connexin gap junction channels (GJCs). Connexin GJCs have emerged as drug targets, with small molecule connexin inhibitors considered a viable therapeutic strategy in several diseases. The molecular mechanisms of GJC inhibition by known small molecule connexin inhibitors remain unknown, preventing the development of more potent and connexin-specific therapeutics. Here we show that two GJC inhibitors, mefloquine (MFQ) and 2-aminoethoxydiphenyl borate (2APB) bind to Cx32 and block dye permeation across Cx32 hemichannels (HCs) and GJCs. Cryo-EM analysis shows that 2APB binds to "site A", close to the N-terminal gating helix of Cx32 GJC, restricting the entrance to the channel pore. In contrast, MFQ binds to a distinct "site M", deeply buried within the pore. MFQ binding to this site modifies the electrostatic properties of Cx32 pore. Mutagenesis of V37, a key residue located in the site M, renders Cx32 HCs and GJCs insensitive to MFQ-mediated inhibition. Moreover, our cryo-EM analysis, mutagenesis and activity assays show that MFQ targets the M site in Cx43 GJC similarly to Cx32. Taken together, our results point to a conserved inhibitor binding site in connexin channels, opening a new route for development of specific drugs targeting connexins. | ||||||
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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PDBx/mmCIF format | ![]() | 423.8 KB | Display | ![]() |
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PDB format | ![]() | 342.7 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 18468MC ![]() 8qjfC ![]() 8qjhC ![]() 8qk6C ![]() 8qkiC M: map data used to model this data C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 43061.336 Da / Num. of mol.: 12 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() Has protein modification | Y | |
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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 |
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Sample preparation
Component | Name: Connexin-32 gap junction channel in complex with 2-aminoethoxydipheniyl borate Type: COMPLEX / Entity ID: all / Source: RECOMBINANT | |||||||||||||||
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Source (natural) | Organism: ![]() | |||||||||||||||
Source (recombinant) | Organism: ![]() | |||||||||||||||
Buffer solution | pH: 8 | |||||||||||||||
Buffer component |
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Specimen | Conc.: 5 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | |||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K |
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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: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 130000 X / Nominal defocus max: 2500 nm / Nominal defocus min: 500 nm / Alignment procedure: COMA FREE |
Specimen holder | Cryogen: NITROGEN |
Image recording | Electron dose: 50 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
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Processing
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.73 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 28940 / Symmetry type: POINT |