201
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Salvage SC, Huang CLH, Jackson AP. Cell-Adhesion Properties of β-Subunits in the Regulation of Cardiomyocyte Sodium Channels. Biomolecules 2020; 10:biom10070989. [PMID: 32630316 PMCID: PMC7407995 DOI: 10.3390/biom10070989] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 06/25/2020] [Accepted: 06/27/2020] [Indexed: 12/17/2022] Open
Abstract
Voltage-gated sodium (Nav) channels drive the rising phase of the action potential, essential for electrical signalling in nerves and muscles. The Nav channel α-subunit contains the ion-selective pore. In the cardiomyocyte, Nav1.5 is the main Nav channel α-subunit isoform, with a smaller expression of neuronal Nav channels. Four distinct regulatory β-subunits (β1–4) bind to the Nav channel α-subunits. Previous work has emphasised the β-subunits as direct Nav channel gating modulators. However, there is now increasing appreciation of additional roles played by these subunits. In this review, we focus on β-subunits as homophilic and heterophilic cell-adhesion molecules and the implications for cardiomyocyte function. Based on recent cryogenic electron microscopy (cryo-EM) data, we suggest that the β-subunits interact with Nav1.5 in a different way from their binding to other Nav channel isoforms. We believe this feature may facilitate trans-cell-adhesion between β1-associated Nav1.5 subunits on the intercalated disc and promote ephaptic conduction between cardiomyocytes.
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Affiliation(s)
- Samantha C. Salvage
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK;
- Correspondence: (S.C.S.); (A.P.J.); Tel.: +44-1223-765950 (S.C.S.); +44-1223-765951 (A.P.J.)
| | - Christopher L.-H. Huang
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK;
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Antony P. Jackson
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK;
- Correspondence: (S.C.S.); (A.P.J.); Tel.: +44-1223-765950 (S.C.S.); +44-1223-765951 (A.P.J.)
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202
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Zhu W, Li T, Silva JR, Chen J. Conservation and divergence in NaChBac and Na V1.7 pharmacology reveals novel drug interaction mechanisms. Sci Rep 2020; 10:10730. [PMID: 32612253 PMCID: PMC7329812 DOI: 10.1038/s41598-020-67761-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 05/13/2020] [Indexed: 01/16/2023] Open
Abstract
Voltage-gated Na+ (NaV) channels regulate homeostasis in bacteria and control membrane electrical excitability in mammals. Compared to their mammalian counterparts, bacterial NaV channels possess a simpler, fourfold symmetric structure and have facilitated studies of the structural basis of channel gating. However, the pharmacology of bacterial NaV remains largely unexplored. Here we systematically screened 39 NaV modulators on a bacterial channel (NaChBac) and characterized a selection of compounds on NaChBac and a mammalian channel (human NaV1.7). We found that while many compounds interact with both channels, they exhibit distinct functional effects. For example, the local anesthetics ambroxol and lidocaine block both NaV1.7 and NaChBac but affect activation and inactivation of the two channels to different extents. The voltage-sensing domain targeting toxin BDS-I increases NaV1.7 but decreases NaChBac peak currents. The pore binding toxins aconitine and veratridine block peak currents of NaV1.7 and shift activation (aconitine) and inactivation (veratridine) respectively. In NaChBac, they block the peak current by binding to the pore residue F224. Nonetheless, aconitine has no effect on activation or inactivation, while veratridine only modulates activation of NaChBac. The conservation and divergence in the pharmacology of bacterial and mammalian NaV channels provide insights into the molecular basis of channel gating and will facilitate organism-specific drug discovery.
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Affiliation(s)
- Wandi Zhu
- Biochemical and Cellular Pharmacology, Genentech Inc., 103 DNA Way, South San Francisco, CA, USA. .,Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
| | - Tianbo Li
- Biochemical and Cellular Pharmacology, Genentech Inc., 103 DNA Way, South San Francisco, CA, USA
| | - Jonathan R Silva
- Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jun Chen
- Biochemical and Cellular Pharmacology, Genentech Inc., 103 DNA Way, South San Francisco, CA, USA.
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203
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Cao Z, Liu L, Hu G, Bian Y, Li H, Wang J, Zhou Y. Interplay of hydrophobic and hydrophilic interactions in sequence-dependent cell penetration of spontaneous membrane-translocating peptides revealed by bias-exchange metadynamics simulations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183402. [PMID: 32569587 DOI: 10.1016/j.bbamem.2020.183402] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 06/14/2020] [Accepted: 06/16/2020] [Indexed: 12/29/2022]
Abstract
Spontaneous Membrane Translocating Peptides (SMTPs) can translocate silently across the bilayer and, thus, have the best potential to improve the delivery of therapeutic molecules to cells without toxicity. However, how their translocation mechanisms are affected by a specific peptide sequence remains poorly understood. Here, bias-exchange metadynamics simulations were employed to investigate the translocation mechanisms of five SMTPs with the same composition of amino acids (LLRLR, LRLLR, LLLRR, RLLLR, and LRLRL). Simulation results yield sequence-dependent free energy barrier using the FESs along the z-directional distance. An in-depth analysis of sequence-dependent interactions in different regions of the bilayers indicates that the free-energy barrier height of a specific sequence is resulted from the accessibility balance of isolated or clustered hydrophobic residues (L) and hydrophilic residues (R) that leads to different levels of resistance for moving of a peptide into the hydrophobic center of the membrane. At the maximal of the free-energy barrier, all peptides have a conformation parallel to the membrane surface with the barrier height determined by their affinity to the hydrophobic region. The appropriate bilayer perturbation and GDM+ pairing are beneficial for peptide translocation. These results provide an improved microscopic understanding of how peptide sequence influences the translocation efficiency and mechanism.
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Affiliation(s)
- Zanxia Cao
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China.
| | - Lei Liu
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China; College of Information Management, Dezhou University, Dezhou 253023, China.
| | - Guodong Hu
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China.
| | - Yunqiang Bian
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China.
| | - Haiyan Li
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China; College of Physics and Electronic Information, Dezhou University, Dezhou 253023, China.
| | - Jihua Wang
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China.
| | - Yaoqi Zhou
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China; Institute for Glycomics, School of Information and Communication Technology, Griffith University, Parklands Dr, Southport, QLD 4222, Australia.
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204
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Employing NaChBac for cryo-EM analysis of toxin action on voltage-gated Na + channels in nanodisc. Proc Natl Acad Sci U S A 2020; 117:14187-14193. [PMID: 32513729 DOI: 10.1073/pnas.1922903117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
NaChBac, the first bacterial voltage-gated Na+ (Nav) channel to be characterized, has been the prokaryotic prototype for studying the structure-function relationship of Nav channels. Discovered nearly two decades ago, the structure of NaChBac has not been determined. Here we present the single particle electron cryomicroscopy (cryo-EM) analysis of NaChBac in both detergent micelles and nanodiscs. Under both conditions, the conformation of NaChBac is nearly identical to that of the potentially inactivated NavAb. Determining the structure of NaChBac in nanodiscs enabled us to examine gating modifier toxins (GMTs) of Nav channels in lipid bilayers. To study GMTs in mammalian Nav channels, we generated a chimera in which the extracellular fragment of the S3 and S4 segments in the second voltage-sensing domain from Nav1.7 replaced the corresponding sequence in NaChBac. Cryo-EM structures of the nanodisc-embedded chimera alone and in complex with HuwenToxin IV (HWTX-IV) were determined to 3.5 and 3.2 Å resolutions, respectively. Compared to the structure of HWTX-IV-bound human Nav1.7, which was obtained at an overall resolution of 3.2 Å, the local resolution of the toxin has been improved from ∼6 to ∼4 Å. This resolution enabled visualization of toxin docking. NaChBac can thus serve as a convenient surrogate for structural studies of the interactions between GMTs and Nav channels in a membrane environment.
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205
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Miao P, Tang S, Ye J, Wang J, Lou Y, Zhang B, Xu X, Chen X, Li Y, Feng J. Electrophysiological features: The next precise step for SCN2A developmental epileptic encephalopathy. Mol Genet Genomic Med 2020; 8:e1250. [PMID: 32400968 PMCID: PMC7336724 DOI: 10.1002/mgg3.1250] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 03/01/2020] [Accepted: 03/05/2020] [Indexed: 12/19/2022] Open
Abstract
Background To investigate the relationships among phenotypes, genotypes, and funotypes of SCN2A‐related developmental epileptic encephalopathy (DEE). Methods We enrolled five DEE patients with five de novo variants of the SCN2A. Functional analysis and pharmacological features of Nav1.2 channel protein expressed in HEK293T cells were characterized by whole‐cell patch‐clamp recording. Results The phenotypes of c.4712T>C(p. I1571T), c.2995G>A(p.E999K), and c.4015A>G(p. N1339D) variants showed similar characteristics, including early seizure onset with severe to profound intellectual disability. Electrophysiological recordings revealed a hyperpolarizing shift in the voltage dependence of the activation curve and smaller recovery time constants of fast‐inactivation than in wild type, indicating a prominent gain of function (GOF). Moreover, pharmacological electrophysiology showed that phenytoin inhibited over a 70% peak current and was more effective than oxcarbazepine and carbamazepine. In contrast, c.4972C>T (p.P1658S) and c.5317G>A (p.A1773T) led to loss of function (LOF) changes, showing reduced current density and enhanced fast inactivation. Both showed seizure onset after 3 months of age with moderate development delay. Interestingly, we discovered that choreoathetosis was a specific phenotype feature. Conclusion These findings provided the insights into the phenotype–genotype–funotype relationships of SCN2A‐related DEE. The preliminary evaluation using the distinct hints of GOF and LOF helped plan the treatment, and the next precise step should be electrophysiological study.
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Affiliation(s)
- Pu Miao
- Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Siyang Tang
- Children's Hospital and Department of Biophysics, National Clinical Research Center for Child Health, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Jia Ye
- Children's Hospital and Department of Biophysics, National Clinical Research Center for Child Health, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianda Wang
- Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuting Lou
- Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Bijun Zhang
- Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoxiao Xu
- Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoquan Chen
- Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuezhou Li
- Children's Hospital and Department of Biophysics, National Clinical Research Center for Child Health, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianhua Feng
- Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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206
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Brewer KR, Kuenze G, Vanoye CG, George AL, Meiler J, Sanders CR. Structures Illuminate Cardiac Ion Channel Functions in Health and in Long QT Syndrome. Front Pharmacol 2020; 11:550. [PMID: 32431610 PMCID: PMC7212895 DOI: 10.3389/fphar.2020.00550] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/09/2020] [Indexed: 12/13/2022] Open
Abstract
The cardiac action potential is critical to the production of a synchronized heartbeat. This electrical impulse is governed by the intricate activity of cardiac ion channels, among them the cardiac voltage-gated potassium (Kv) channels KCNQ1 and hERG as well as the voltage-gated sodium (Nav) channel encoded by SCN5A. Each channel performs a highly distinct function, despite sharing a common topology and structural components. These three channels are also the primary proteins mutated in congenital long QT syndrome (LQTS), a genetic condition that predisposes to cardiac arrhythmia and sudden cardiac death due to impaired repolarization of the action potential and has a particular proclivity for reentrant ventricular arrhythmias. Recent cryo-electron microscopy structures of human KCNQ1 and hERG, along with the rat homolog of SCN5A and other mammalian sodium channels, provide atomic-level insight into the structure and function of these proteins that advance our understanding of their distinct functions in the cardiac action potential, as well as the molecular basis of LQTS. In this review, the gating, regulation, LQTS mechanisms, and pharmacological properties of KCNQ1, hERG, and SCN5A are discussed in light of these recent structural findings.
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Affiliation(s)
- Kathryn R. Brewer
- Center for Structural Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Department of Biochemistry, Vanderbilt University, Nashville, TN, United States
| | - Georg Kuenze
- Center for Structural Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Carlos G. Vanoye
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Alfred L. George
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Department of Pharmacology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - Charles R. Sanders
- Center for Structural Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Department of Biochemistry, Vanderbilt University, Nashville, TN, United States
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207
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Ghovanloo MR, Ruben PC. Say Cheese: Structure of the Cardiac Electrical Engine Is Captured. Trends Biochem Sci 2020; 45:369-371. [DOI: 10.1016/j.tibs.2020.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 01/28/2020] [Accepted: 02/06/2020] [Indexed: 12/21/2022]
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208
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Thull S, Neacsu C, O'Reilly AO, Bothe S, Hausmann R, Huth T, Meents J, Lampert A. Mechanism underlying hooked resurgent-like tail currents induced by an insecticide in human cardiac Nav1.5. Toxicol Appl Pharmacol 2020; 397:115010. [PMID: 32302602 DOI: 10.1016/j.taap.2020.115010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/12/2020] [Accepted: 04/14/2020] [Indexed: 01/02/2023]
Abstract
Voltage-gated sodium channels are responsible not only for the fast upstroke of the action potential, but they also modify cellular excitability via persistent and resurgent currents. Insecticides act via permanently opening sodium channels to immobilize the animals. Cellular recordings performed decades ago revealed distinctly hooked tail currents induced by these compounds. Here, we applied the classical type-II pyrethroid deltamethrin on human cardiac Nav1.5 and observed resurgent-like currents at very negative potentials in the absence of any pore-blocker, which resemble those hooked tail currents. We show that deltamethrin dramatically slows both fast inactivation and deactivation of Nav1.5 and thereby induces large persistent currents. Using the sea anemone toxin ATx-II as a tool to prevent all inactivation-related processes, resurgent-like currents were eliminated while persistent currents were preserved. Our experiments suggest that, in deltamethrin-modified channels, recovery from inactivation occurs faster than delayed deactivation, opening a brief window for sodium influx and leading to hooked, resurgent-like currents, in the absence of an open channel blocker. Thus, we now explain with pharmacological methods the biophysical gating changes underlying the deltamethrin induced hooked tail currents. SUMMARY: The pyrethroid deltamethrin induces hooked resurgent-like tail currents in human cardiac voltage-gated Nav1.5 channels. Using deltamethrin and ATx-II, we identify additional conducting channel states caused by a faster recovery from inactivation compared to the deltamethrin-induced delayed deactivation.
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Affiliation(s)
- Sarah Thull
- Institute of Physiology, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany
| | - Cristian Neacsu
- Institut für Physiologie und Pathophysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitaetsstr. 17, 91054 Erlangen, Germany
| | - Andrias O O'Reilly
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK
| | - Stefanie Bothe
- Institute of Physiology, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany; Research Training Group 2416 MultiSenses-MultiScales, RWTH Aachen University, Aachen, Germany
| | - Ralf Hausmann
- Institute of Clinical Pharmacology, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
| | - Tobias Huth
- Institut für Physiologie und Pathophysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitaetsstr. 17, 91054 Erlangen, Germany
| | - Jannis Meents
- Institute of Physiology, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany.
| | - Angelika Lampert
- Institute of Physiology, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany; Research Training Group 2416 MultiSenses-MultiScales, RWTH Aachen University, Aachen, Germany; Research Training Group 2415 ME3T, RWTH Aachen University, Aachen, Germany.
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209
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van Goor MK, de Jager L, Cheng Y, van der Wijst J. High-resolution structures of transient receptor potential vanilloid channels: Unveiling a functionally diverse group of ion channels. Protein Sci 2020; 29:1569-1580. [PMID: 32232875 PMCID: PMC7314393 DOI: 10.1002/pro.3861] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 03/21/2020] [Accepted: 03/24/2020] [Indexed: 12/13/2022]
Abstract
Transient receptor potential vanilloid (TRPV) channels are part of the superfamily of TRP ion channels and play important roles in widespread physiological processes including both neuronal and non‐neuronal pathways. Various diseases such as skeletal abnormalities, chronic pain, and cancer are associated with dysfunction of a TRPV channel. In order to obtain full understanding of disease pathogenesis and create opportunities for therapeutic intervention, it is essential to unravel how these channels function at a molecular level. In the past decade, incredible progress has been made in biochemical sample preparation of large membrane proteins and structural biology techniques, including cryo‐electron microscopy. This has resulted in high resolution structures of all TRPV channels, which has provided novel insights into the molecular mechanisms of channel gating and regulation that will be summarized in this review.
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Affiliation(s)
- Mark K van Goor
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Leanne de Jager
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, United States.,Howard Hughes Medical Institute, University of California, San Francisco, California, United States
| | - Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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210
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Malak OA, Abderemane-Ali F, Wei Y, Coyan FC, Pontus G, Shaya D, Marionneau C, Loussouarn G. Up-regulation of voltage-gated sodium channels by peptides mimicking S4-S5 linkers reveals a variation of the ligand-receptor mechanism. Sci Rep 2020; 10:5852. [PMID: 32246066 PMCID: PMC7125111 DOI: 10.1038/s41598-020-62615-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 03/12/2020] [Indexed: 11/09/2022] Open
Abstract
Prokaryotic NaV channels are tetramers and eukaryotic NaV channels consist of a single subunit containing four domains. Each monomer/domain contains six transmembrane segments (S1-S6), S1-S4 being the voltage-sensor domain and S5-S6 the pore domain. A crystal structure of NaVMs, a prokaryotic NaV channel, suggests that the S4-S5 linker (S4-S5L) interacts with the C-terminus of S6 (S6T) to stabilize the gate in the open state. However, in several voltage-gated potassium channels, using specific S4-S5L-mimicking peptides, we previously demonstrated that S4-S5L/S6T interaction stabilizes the gate in the closed state. Here, we used the same strategy on another prokaryotic NaV channel, NaVSp1, to test whether equivalent peptides stabilize the channel in the open or closed state. A NaVSp1-specific S4-S5L peptide, containing the residues supposed to interact with S6T according to the NaVMs structure, induced both an increase in NaVSp1 current density and a negative shift in the activation curve, consistent with S4-S5L stabilizing the open state. Using this approach on a human NaV channel, hNaV1.4, and testing 12 hNaV1.4 S4-S5L peptides, we identified four activating S4-S5L peptides. These results suggest that, in eukaryotic NaV channels, the S4-S5L of DI, DII and DIII domains allosterically modulate the activation gate and stabilize its open state.
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Affiliation(s)
- Olfat A Malak
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France.,Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, California, 94945, USA
| | - Fayal Abderemane-Ali
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France.,Cardiovascular Research Institute, University of California, San Francisco, California, 941158-9001, USA
| | - Yue Wei
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France.,Department of Cardiology, Shanghai Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fabien C Coyan
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - Gilyane Pontus
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - David Shaya
- Cardiovascular Research Institute, University of California, San Francisco, California, 941158-9001, USA
| | - Céline Marionneau
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - Gildas Loussouarn
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France.
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211
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Zhao Y, Huang G, Wu J, Wu Q, Gao S, Yan Z, Lei J, Yan N. Molecular Basis for Ligand Modulation of a Mammalian Voltage-Gated Ca 2+ Channel. Cell 2020; 177:1495-1506.e12. [PMID: 31150622 DOI: 10.1016/j.cell.2019.04.043] [Citation(s) in RCA: 154] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/23/2019] [Accepted: 04/25/2019] [Indexed: 10/26/2022]
Abstract
The L-type voltage-gated Ca2+ (Cav) channels are modulated by various compounds exemplified by 1,4-dihydropyridines (DHP), benzothiazepines (BTZ), and phenylalkylamines (PAA), many of which have been used for characterizing channel properties and for treatment of hypertension and other disorders. Here, we report the cryoelectron microscopy (cryo-EM) structures of Cav1.1 in complex with archetypal antagonistic drugs, nifedipine, diltiazem, and verapamil, at resolutions of 2.9 Å, 3.0 Å, and 2.7 Å, respectively, and with a DHP agonist Bay K 8644 at 2.8 Å. Diltiazem and verapamil traverse the central cavity of the pore domain, directly blocking ion permeation. Although nifedipine and Bay K 8644 occupy the same fenestration site at the interface of repeats III and IV, the coordination details support previous functional observations that Bay K 8644 is less favored in the inactivated state. These structures elucidate the modes of action of different Cav ligands and establish a framework for structure-guided drug discovery.
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Affiliation(s)
- Yanyu Zhao
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Gaoxingyu Huang
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jianping Wu
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
| | - Qiurong Wu
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shuai Gao
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Zhen Yan
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jianlin Lei
- Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Nieng Yan
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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212
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Glass WG, Duncan AL, Biggin PC. Computational Investigation of Voltage-Gated Sodium Channel β3 Subunit Dynamics. Front Mol Biosci 2020; 7:40. [PMID: 32266288 PMCID: PMC7103644 DOI: 10.3389/fmolb.2020.00040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/19/2020] [Indexed: 01/23/2023] Open
Abstract
Voltage-gated sodium (Na v ) channels form the basis for the initiation of the action potential in excitable cells by allowing sodium ions to pass through the cell membrane. The Na v channel α subunit is known to function both with and without associated β subunits. There is increasing evidence that these β subunits have multiple roles that include not only influencing the voltage-dependent gating but also the ability to alter the spatial distribution of the pore-forming α subunit. Recent structural data has shown possible ways in which β1 subunits may interact with the α subunit. However, the position of the β1 subunit would not be compatible with a previous trimer structure of the β3 subunit. Furthermore, little is currently known about the dynamic behavior of the β subunits both as individual monomers and as higher order oligomers. Here, we use multiscale molecular dynamics simulations to assess the dynamics of the β3, and the closely related, β1 subunit. These findings reveal the spatio-temporal dynamics of β subunits and should provide a useful framework for interpreting future low-resolution experiments such as atomic force microscopy.
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Affiliation(s)
| | | | - Philip C. Biggin
- Structural Bioinformatics and Computational Biochemistry, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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213
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Horie R, Kubota T, Koh J, Tanaka R, Nakamura Y, Sasaki R, Ito H, Takahashi MP. EF hand-like motif mutations of Nav1.4 C-terminus cause myotonic syndrome by impairing fast inactivation. Muscle Nerve 2020; 61:808-814. [PMID: 32129495 DOI: 10.1002/mus.26849] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 01/27/2020] [Accepted: 03/01/2020] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Mutations of the voltage-gated sodium channel gene (SCN4A), which encodes Nav1.4, cause nondystrophic myotonia that occasionally is associated with severe apnea and laryngospasm. There are case reports of nondystrophic myotonia due to mutations in the C-terminal tail (CTerm) of Nav1.4, but the functional analysis is scarce. METHODS We present two families with nondystrophic myotonia harboring a novel heterozygous mutation (E1702del) and a known heterozygous mutation (E1702K). RESULTS The proband with E1702K exhibited repeated rhabdomyolysis, and the daughter showed laryngospasm and cyanosis. Functional analysis of the two mutations as well as another known heterozygous mutation (T1700_E1703del), all located on EF hand-like motif in CTerm, was conducted with whole-cell recording of heterologously expressed channel. All mutations displayed impaired fast inactivation. DISCUSSION The CTerm of Nav1.4 is vital for regulating fast inactivation. The study highlights the importance of accumulating pathological mutations of Nav1.4 and their functional analysis data.
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Affiliation(s)
- Riho Horie
- Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Yamadaoka, Suita, Osaka, Japan
| | - Tomoya Kubota
- Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Yamadaoka, Suita, Osaka, Japan
| | - Jinsoo Koh
- Department of Neurology, Wakayama Medical University, Kimiidera, Wakayama, Wakayama, Japan
| | - Rieko Tanaka
- Nanairo Kodomo Clinic, Fukiage, Wakayama, Wakayama, Japan
| | - Yuichiro Nakamura
- Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Yamadaoka, Suita, Osaka, Japan
| | - Ryogen Sasaki
- Department of Neurology, Kuwana City Medical Center, Kotobukicho, Kuwana, Mie, Japan
| | - Hidefumi Ito
- Department of Neurology, Wakayama Medical University, Kimiidera, Wakayama, Wakayama, Japan
| | - Masanori P Takahashi
- Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Yamadaoka, Suita, Osaka, Japan
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214
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Salvage SC, Rees JS, McStea A, Hirsch M, Wang L, Tynan CJ, Reed MW, Irons JR, Butler R, Thompson AJ, Martin-Fernandez ML, Huang CL, Jackson AP. Supramolecular clustering of the cardiac sodium channel Nav1.5 in HEK293F cells, with and without the auxiliary β3-subunit. FASEB J 2020; 34:3537-3553. [PMID: 31950564 PMCID: PMC7079131 DOI: 10.1096/fj.201701473rr] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 09/30/2019] [Accepted: 10/08/2019] [Indexed: 01/24/2023]
Abstract
Voltage-gated sodium channels comprise an ion-selective α-subunit and one or more associated β-subunits. The β3-subunit (encoded by the SCN3B gene) is an important physiological regulator of the heart-specific sodium channel, Nav1.5. We have previously shown that when expressed alone in HEK293F cells, the full-length β3-subunit forms trimers in the plasma membrane. We extend this result with biochemical assays and use the proximity ligation assay (PLA) to identify oligomeric β3-subunits, not just at the plasma membrane, but throughout the secretory pathway. We then investigate the corresponding clustering properties of the α-subunit and the effects upon these of the β3-subunits. The oligomeric status of the Nav1.5 α-subunit in vivo, with or without the β3-subunit, has not been previously investigated. Using super-resolution fluorescence imaging, we show that under conditions typically used in electrophysiological studies, the Nav1.5 α-subunit assembles on the plasma membrane of HEK293F cells into spatially localized clusters rather than individual and randomly dispersed molecules. Quantitative analysis indicates that the β3-subunit is not required for this clustering but β3 does significantly change the distribution of cluster sizes and nearest-neighbor distances between Nav1.5 α-subunits. However, when assayed by PLA, the β3-subunit increases the number of PLA-positive signals generated by anti-(Nav1.5 α-subunit) antibodies, mainly at the plasma membrane. Since PLA can be sensitive to the orientation of proteins within a cluster, we suggest that the β3-subunit introduces a significant change in the relative alignment of individual Nav1.5 α-subunits, but the clustering itself depends on other factors. We also show that these structural and higher-order changes induced by the β3-subunit do not alter the degree of electrophysiological gating cooperativity between Nav1.5 α-subunits. Our data provide new insights into the role of the β3-subunit and the supramolecular organization of sodium channels, in an important model cell system that is widely used to study Nav channel behavior.
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Affiliation(s)
| | | | - Alexandra McStea
- Central Laser FacilityResearch Complex at HarwellScience and Technology Facilities CouncilRutherford Appleton LaboratoryOxfordUK
| | - Michael Hirsch
- Central Laser FacilityResearch Complex at HarwellScience and Technology Facilities CouncilRutherford Appleton LaboratoryOxfordUK
| | - Lin Wang
- Central Laser FacilityResearch Complex at HarwellScience and Technology Facilities CouncilRutherford Appleton LaboratoryOxfordUK
| | - Christopher J. Tynan
- Central Laser FacilityResearch Complex at HarwellScience and Technology Facilities CouncilRutherford Appleton LaboratoryOxfordUK
| | - Matthew W. Reed
- Department of Nuclear PhysicsResearch School of Physics and EngineeringAustralian National UniversityCanberrraACTAustralia
| | | | - Richard Butler
- Wellcome Trust/Cancer Research UK Gurdon InstituteUniversity of CambridgeCambridgeUK
| | | | - Marisa L. Martin-Fernandez
- Central Laser FacilityResearch Complex at HarwellScience and Technology Facilities CouncilRutherford Appleton LaboratoryOxfordUK
| | - Christopher L.‐H. Huang
- Deparment of BiochemistryUniversity of CambridgeCambridgeUK
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUK
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215
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Groome JR, Bayless-Edwards L. Roles for Countercharge in the Voltage Sensor Domain of Ion Channels. Front Pharmacol 2020; 11:160. [PMID: 32180723 PMCID: PMC7059764 DOI: 10.3389/fphar.2020.00160] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/07/2020] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated ion channels share a common structure typified by peripheral, voltage sensor domains. Their S4 segments respond to alteration in membrane potential with translocation coupled to ion permeation through a central pore domain. The mechanisms of gating in these channels have been intensely studied using pioneering methods such as measurement of charge displacement across a membrane, sequencing of genes coding for voltage-gated ion channels, and the development of all-atom molecular dynamics simulations using structural information from prokaryotic and eukaryotic channel proteins. One aspect of this work has been the description of the role of conserved negative countercharges in S1, S2, and S3 transmembrane segments to promote sequential salt-bridge formation with positively charged residues in S4 segments. These interactions facilitate S4 translocation through the lipid bilayer. In this review, we describe functional and computational work investigating the role of these countercharges in S4 translocation, voltage sensor domain hydration, and in diseases resulting from countercharge mutations.
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Affiliation(s)
- James R. Groome
- Department of Biological Sciences, Idaho State University, Pocatello, ID, United States
| | - Landon Bayless-Edwards
- Department of Biological Sciences, Idaho State University, Pocatello, ID, United States
- Oregon Health and Sciences University School of Medicine, Portland, OR, United States
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216
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Bajaj S, Ong ST, Chandy KG. Contributions of natural products to ion channel pharmacology. Nat Prod Rep 2020; 37:703-716. [PMID: 32065187 DOI: 10.1039/c9np00056a] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Covering: Up to 2020Ion channels are a vast super-family of membrane proteins that play critical physiological roles in excitable and non-excitable cells. Their biomedical importance makes them valuable and attractive drug targets for neurological, cardiovascular, gastrointestinal and metabolic diseases, and for cancer therapy and immune modulation. Current therapeutics target only a minor subset of ion channels, leaving a large unexploited space within the ion channel field. Natural products harnessed from the almost unlimited and diverse universe of compounds within the bioenvironment have been used to modulate channels for decades. In this review we highlight the impact made by natural products on ion channel pharmacology, specifically on K+, NaV and CaV channels, and use case studies to describe the development of ion channel-modulating drugs from natural sources for the treatment of pain, heart disease and autoimmune diseases.
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Affiliation(s)
- Saumya Bajaj
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Experimental Medicine Building, 59 Nanyang Drive, 636921, Singapore.
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217
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Lev B, Allen TW. Simulating ion channel activation mechanisms using swarms of trajectories. J Comput Chem 2020; 41:387-401. [PMID: 31743478 DOI: 10.1002/jcc.26102] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 12/14/2022]
Abstract
Atomic-level studies of protein activity represent a significant challenge as a result of the complexity of conformational changes occurring on wide-ranging timescales, often greatly exceeding that of even the longest simulations. A prime example is the elucidation of protein allosteric mechanisms, where localized perturbations transmit throughout a large macromolecule to generate a response signal. For example, the conversion of chemical to electrical signals during synaptic neurotransmission in the brain is achieved by specialized membrane proteins called pentameric ligand-gated ion channels. Here, the binding of a neurotransmitter results in a global conformational change to open an ion-conducting pore across the nerve cell membrane. X-ray crystallography has produced static structures of the open and closed states of the proton-gated GLIC pentameric ligand-gated ion channel protein, allowing for atomistic simulations that can uncover changes related to activation. We discuss a range of enhanced sampling approaches that could be used to explore activation mechanisms. In particular, we describe recent application of an atomistic string method, based on Roux's "swarms of trajectories" approach, to elucidate the sequence and interdependence of conformational changes during activation. We illustrate how this can be combined with transition analysis and Brownian dynamics to extract thermodynamic and kinetic information, leading to understanding of what controls ion channel function. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Bogdan Lev
- School of Science, RMIT University, Melbourne, Victoria, 3000, Australia
| | - Toby W Allen
- School of Science, RMIT University, Melbourne, Victoria, 3000, Australia
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218
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Elia N, Nault T, McMillan HJ, Graham GE, Huang L, Cannon SC. Myotonic Myopathy With Secondary Joint and Skeletal Anomalies From the c.2386C>G, p.L769V Mutation in SCN4A. Front Neurol 2020; 11:77. [PMID: 32117035 PMCID: PMC7031655 DOI: 10.3389/fneur.2020.00077] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/22/2020] [Indexed: 11/22/2022] Open
Abstract
The phenotypic spectrum associated with the skeletal muscle voltage-gated sodium channel gene (SCN4A) has expanded with advancements in genetic testing. Autosomal dominant SCN4A mutations were first linked to hyperkalemic periodic paralysis, then subsequently included paramyotonia congenita, several variants of myotonia, and finally hypokalemic periodic paralysis. Biallelic recessive mutations were later identified in myasthenic myopathy and in infants showing a severe congenital myopathy with hypotonia. We report a patient with a pathogenic de novo SCN4A variant, c.2386C>G p.L769V at a highly conserved leucine. The phenotype was manifest at birth with arthrogryposis multiplex congenita, severe episodes of bronchospasm that responded immediately to carbamazepine therapy, and electromyographic evidence of widespread myotonia. Another de novo case of p.L769V has been reported with hip dysplasia, scoliosis, myopathy, and later paramyotonia. Expression studies of L796V mutant channels showed predominantly gain-of-function changes, that included defects of slow inactivation. Computer simulations of muscle excitability reveal a strong predisposition to myotonia with exceptionally prolonged bursts of discharges, when the L796V defects are included. We propose L769V is a pathogenic variant, that along with other cases in the literature, defines a new dominant SCN4A disorder of myotonic myopathy with secondary congenital joint and skeletal involvement.
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Affiliation(s)
- Nathaniel Elia
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
- Molecular, Cellular, and Integrative Physiology Program, UCLA, Los Angeles, CA, United States
| | - Trystan Nault
- Division of Neurology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada
| | - Hugh J. McMillan
- Division of Neurology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada
| | - Gail E. Graham
- Department of Genetics, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada
| | - Lijia Huang
- Department of Genetics, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada
| | - Stephen C. Cannon
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
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219
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Craig RA, Garrison CE, Nguyen PT, Yarov-Yarovoy V, Du Bois J. Veratridine: A Janus-Faced Modulator of Voltage-Gated Sodium Ion Channels. ACS Chem Neurosci 2020; 11:418-426. [PMID: 31951114 DOI: 10.1021/acschemneuro.9b00621] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Voltage-gated sodium ion channels (NaVs) are integral to both neuronal and muscular signaling and are a primary target for a number of proteinaceous and small molecule toxins. Included among these neurotoxins is veratridine (VTD), a C-nor-D homosteroidal alkaloid from the seeds of members of the Veratrum genus. VTD binds to NaV within the pore region, causing a hyperpolarizing shift in the activation threshold in addition to reducing peak current. We have characterized the activity of VTD against heterologously expressed rat NaV1.4 and have demonstrated that VTD acts on the channel as either an agonist or antagonist depending on the nature of the electrophysiological stimulation protocol. Structure-activity studies with VTD and VTD derivatives against NaV mutants show that the functional duality of VTD can be decoupled. These findings suggest that the dichotomous activity of VTD may derive from two distinct, use-dependent binding orientations of the toxin.
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Affiliation(s)
- Robert A. Craig
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Catherine E. Garrison
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Phuong T. Nguyen
- Department of Physiology and Membrane Biology, University of California, Davis, California 95616, United States
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, California 95616, United States
| | - J. Du Bois
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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220
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Gade AR, Marx SO, Pitt GS. An interaction between the III-IV linker and CTD in NaV1.5 confers regulation of inactivation by CaM and FHF. J Gen Physiol 2020; 152:e201912434. [PMID: 31865383 PMCID: PMC7062510 DOI: 10.1085/jgp.201912434] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 11/25/2019] [Indexed: 12/19/2022] Open
Abstract
Voltage gated sodium channel (VGSC) activation drives the action potential upstroke in cardiac myocytes, skeletal muscles, and neurons. After opening, VGSCs rapidly enter a non-conducting, inactivated state. Impaired inactivation causes persistent inward current and underlies cardiac arrhythmias. VGSC auxiliary proteins calmodulin (CaM) and fibroblast growth factor homologous factors (FHFs) bind to the channel's C-terminal domain (CTD) and limit pathogenic persistent currents. The structural details and mechanisms mediating these effects are not clear. Building on recently published cryo-EM structures, we show that CaM and FHF limit persistent currents in the cardiac NaV1.5 VGSC by stabilizing an interaction between the channel's CTD and III-IV linker region. Perturbation of this intramolecular interaction increases persistent current and shifts the voltage dependence of steady-state inactivation. Interestingly, the NaV1.5 residues involved in the interaction are sites mutated in the arrhythmogenic long QT3 syndrome (LQT3). Along with electrophysiological investigations of this interaction, we present structural models that suggest how CaM and FHF stabilize the interaction and thereby limit the persistent current. The critical residues at the interaction site are conserved among VGSC isoforms, and subtle substitutions provide an explanation for differences in inactivation among the isoforms.
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Affiliation(s)
- Aravind R. Gade
- Cardiovascular Research Institute, Weill Cornell Medicine, New York, NY
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Pharmacology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Geoffrey S. Pitt
- Cardiovascular Research Institute, Weill Cornell Medicine, New York, NY
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221
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Adachi K, Yamada T, Ishizuka H, Oki M, Tsunogae S, Shimada N, Chiba O, Orihara T, Hidaka M, Hirokawa T, Odagi M, Konoki K, Yotsu‐Yamashita M, Nagasawa K. Synthesis of C12‐Keto Saxitoxin Derivatives with Unusual Inhibitory Activity Against Voltage‐Gated Sodium Channels. Chemistry 2020; 26:2025-2033. [DOI: 10.1002/chem.201904184] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/04/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Kanna Adachi
- Department of Biotechnology and Life Science Faculty of Technology Tokyo University of Agriculture and Technology 2-24-16 Naka-cho Koganei Tokyo 184-8588 Japan
| | - Tomoshi Yamada
- Graduate School of Agriculture Science Tohoku University 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-8572 Japan
| | - Hayate Ishizuka
- Department of Biotechnology and Life Science Faculty of Technology Tokyo University of Agriculture and Technology 2-24-16 Naka-cho Koganei Tokyo 184-8588 Japan
| | - Mana Oki
- Department of Biotechnology and Life Science Faculty of Technology Tokyo University of Agriculture and Technology 2-24-16 Naka-cho Koganei Tokyo 184-8588 Japan
| | - Shunsuke Tsunogae
- Graduate School of Agriculture Science Tohoku University 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-8572 Japan
| | - Noriko Shimada
- Graduate School of Agriculture Science Tohoku University 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-8572 Japan
| | - Osamu Chiba
- Graduate School of Agriculture Science Tohoku University 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-8572 Japan
| | - Tatsuya Orihara
- Department of Biotechnology and Life Science Faculty of Technology Tokyo University of Agriculture and Technology 2-24-16 Naka-cho Koganei Tokyo 184-8588 Japan
| | - Masafumi Hidaka
- Graduate School of Agriculture Science Tohoku University 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-8572 Japan
| | - Takatsugu Hirokawa
- Transborder Medical Research Center University of Tsukuba 1-1-1 Tennodai Tsukuba 305-8575 Japan
- Division of Biomedical Science University of Tsukuba 1-1-1 Tennodai Tsukuba 305-8575 Japan
- Molecular Profiling Research Center for Drug Discovery National Institute of Advanced Industrial Science and Technology 2-4-7 Aomi, Koto-ward Tokyo 135-0064 Japan
| | - Minami Odagi
- Department of Biotechnology and Life Science Faculty of Technology Tokyo University of Agriculture and Technology 2-24-16 Naka-cho Koganei Tokyo 184-8588 Japan
| | - Keiichi Konoki
- Graduate School of Agriculture Science Tohoku University 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-8572 Japan
| | - Mari Yotsu‐Yamashita
- Graduate School of Agriculture Science Tohoku University 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-8572 Japan
| | - Kazuo Nagasawa
- Department of Biotechnology and Life Science Faculty of Technology Tokyo University of Agriculture and Technology 2-24-16 Naka-cho Koganei Tokyo 184-8588 Japan
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222
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Beard JM, Shockett PE, O'Reilly JP. Substituted cysteine scanning in D1-S6 of the sodium channel hNav1.4 alters kinetics and structural interactions of slow inactivation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183129. [PMID: 31738900 DOI: 10.1016/j.bbamem.2019.183129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 10/25/2019] [Accepted: 11/08/2019] [Indexed: 10/25/2022]
Abstract
Slow inactivation in voltage-gated Na+ channels (Navs) plays an important physiological role in excitable tissues (muscle, heart, nerves) and mutations that disrupt Nav slow inactivation can result in pathophysiologies (myotonia, arrhythmias, epilepsy). While the molecular mechanisms responsible for slow inactivation remain elusive, previous studies have suggested a role for the pore-lining D1-S6 helix. The goals of this research were to determine if (1) cysteine substitutions in D1-S6 affect gating kinetics and (2) methanethiosulfonate ethylammonium (MTSEA) accessibility changes in different kinetic states. Site-directed mutagenesis in the human skeletal muscle isoform hNav1.4 was used to substitute cysteine for eleven amino acids in D1-S6 from L433 to L443. Mutants were expressed in HEK cells and recorded from with whole-cell patch clamp. All mutations affected one or more baseline kinetics of the sodium channel, including activation, fast inactivation, and slow inactivation. Substitution of cysteine (for nonpolar residues) adjacent to polar residues destabilized slow inactivation in G434C, F436C, I439C, and L441C. Cysteine substitution without adjacent polar residues enhanced slow inactivation in L438C and N440C, and disrupted possible H-bonds involving Y437:D4 S4-S5 and N440:D4-S6. MTSEA exposure in closed, fast-inactivated, or slow-inactivated states in most mutants had little-to-no effect. In I439C, MTSEA application in closed, fast-inactivated, and slow-inactivated states produced irreversible reduction in current, suggesting I439C accessibility to MTSEA in all three kinetic states. D1-S6 is important for Nav gating kinetics, stability of slow-inactivated state, structural contacts, and state-dependent positioning. However, prominent reconfiguration of D1-S6 may not occur in slow inactivation.
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Affiliation(s)
- Jonathan M Beard
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA, USA.
| | - Penny E Shockett
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA, USA.
| | - John P O'Reilly
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA, USA.
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223
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Kalina RS, Peigneur S, Zelepuga EA, Dmitrenok PS, Kvetkina AN, Kim NY, Leychenko EV, Tytgat J, Kozlovskaya EP, Monastyrnaya MM, Gladkikh IN. New Insights into the Type II Toxins from the Sea Anemone Heteractis crispa. Toxins (Basel) 2020; 12:E44. [PMID: 31936885 PMCID: PMC7020476 DOI: 10.3390/toxins12010044] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 12/23/2022] Open
Abstract
Toxins modulating NaV channels are the most abundant and studied peptide components of sea anemone venom. Three type-II toxins, δ-SHTX-Hcr1f (= RpII), RTX-III, and RTX-VI, were isolated from the sea anemone Heteractis crispa. RTX-VI has been found to be an unusual analog of RTX-III. The electrophysiological effects of Heteractis toxins on nine NaV subtypes were investigated for the first time. Heteractis toxins mainly affect the inactivation of the mammalian NaV channels expressed in the central nervous system (NaV1.1-NaV1.3, NaV1.6) as well as insect and arachnid channels (BgNaV1, VdNaV1). The absence of Arg13 in the RTX-VI structure does not prevent toxin binding with the channel but it has changed its pharmacological profile and potency. According to computer modeling data, the δ-SHTX-Hcr1f binds within the extracellular region of the rNaV1.2 voltage-sensing domain IV and pore-forming domain I through a network of strong interactions, and an additional fixation of the toxin at the channel binding site is carried out through the phospholipid environment. Our data suggest that Heteractis toxins could be used as molecular tools for NaV channel studies or insecticides rather than as pharmacological agents.
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Affiliation(s)
- Rimma S. Kalina
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 690022 Vladivostok, Russia; (E.A.Z.); (P.S.D.); (A.N.K.); (N.Y.K.); (E.V.L.); (E.P.K.); (M.M.M.)
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N 2, Herestraat~49, P.O. Box 922, 3000 Leuven, Belgium
| | - Elena A. Zelepuga
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 690022 Vladivostok, Russia; (E.A.Z.); (P.S.D.); (A.N.K.); (N.Y.K.); (E.V.L.); (E.P.K.); (M.M.M.)
| | - Pavel S. Dmitrenok
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 690022 Vladivostok, Russia; (E.A.Z.); (P.S.D.); (A.N.K.); (N.Y.K.); (E.V.L.); (E.P.K.); (M.M.M.)
| | - Aleksandra N. Kvetkina
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 690022 Vladivostok, Russia; (E.A.Z.); (P.S.D.); (A.N.K.); (N.Y.K.); (E.V.L.); (E.P.K.); (M.M.M.)
| | - Natalia Y. Kim
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 690022 Vladivostok, Russia; (E.A.Z.); (P.S.D.); (A.N.K.); (N.Y.K.); (E.V.L.); (E.P.K.); (M.M.M.)
| | - Elena V. Leychenko
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 690022 Vladivostok, Russia; (E.A.Z.); (P.S.D.); (A.N.K.); (N.Y.K.); (E.V.L.); (E.P.K.); (M.M.M.)
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N 2, Herestraat~49, P.O. Box 922, 3000 Leuven, Belgium
| | - Emma P. Kozlovskaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 690022 Vladivostok, Russia; (E.A.Z.); (P.S.D.); (A.N.K.); (N.Y.K.); (E.V.L.); (E.P.K.); (M.M.M.)
| | - Margarita M. Monastyrnaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 690022 Vladivostok, Russia; (E.A.Z.); (P.S.D.); (A.N.K.); (N.Y.K.); (E.V.L.); (E.P.K.); (M.M.M.)
| | - Irina N. Gladkikh
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 690022 Vladivostok, Russia; (E.A.Z.); (P.S.D.); (A.N.K.); (N.Y.K.); (E.V.L.); (E.P.K.); (M.M.M.)
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224
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Catterall WA, Lenaeus MJ, Gamal El-Din TM. Structure and Pharmacology of Voltage-Gated Sodium and Calcium Channels. Annu Rev Pharmacol Toxicol 2020; 60:133-154. [PMID: 31537174 DOI: 10.1146/annurev-pharmtox-010818-021757] [Citation(s) in RCA: 146] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Voltage-gated sodium and calcium channels are evolutionarily related transmembrane signaling proteins that initiate action potentials, neurotransmission, excitation-contraction coupling, and other physiological processes. Genetic or acquired dysfunction of these proteins causes numerous diseases, termed channelopathies, and sodium and calcium channels are the molecular targets for several major classes of drugs. Recent advances in the structural biology of these proteins using X-ray crystallography and cryo-electron microscopy have given new insights into the molecular basis for their function and pharmacology. Here we review this recent literature and integrate findings on sodium and calcium channels to reveal the structural basis for their voltage-dependent activation, fast and slow inactivation, ion conductance and selectivity, and complex pharmacology at the atomic level. We conclude with the theme that new understanding of the diseases and therapeutics of these channels will be derived from application of the emerging structural principles from these recent structural analyses.
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Affiliation(s)
- William A Catterall
- Department of Pharmacology and Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, Washington 98195, USA;
| | - Michael J Lenaeus
- Department of Pharmacology and Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, Washington 98195, USA;
| | - Tamer M Gamal El-Din
- Department of Pharmacology and Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, Washington 98195, USA;
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225
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Wang H, Foquet B, Dewell RB, Song H, Dierick HA, Gabbiani F. Molecular characterization and distribution of the voltage-gated sodium channel, Para, in the brain of the grasshopper and vinegar fly. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2020; 206:289-307. [PMID: 31902005 DOI: 10.1007/s00359-019-01396-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/10/2019] [Accepted: 12/14/2019] [Indexed: 11/29/2022]
Abstract
Voltage-gated sodium (NaV) channels, encoded by the gene para, play a critical role in the rapid processing and propagation of visual information related to collision avoidance behaviors. We investigated their localization by immunostaining the optic lobes and central brain of the grasshopper Schistocerca americana and the vinegar fly Drosophila melanogaster with an antibody that recognizes the channel peptide domain responsible for fast inactivation gating. NaV channels were detected at high density at all stages of development. In the optic lobe, they revealed stereotypically repeating fascicles consistent with the regular structure of the eye. In the central brain, major axonal tracts were strongly labeled, particularly in the grasshopper olfactory system. We used the NaV channel sequence of Drosophila to identify an ortholog in the transcriptome of Schistocerca. The grasshopper, vinegar fly, and human NaV channels exhibit a high degree of conservation at gating and ion selectivity domains. Comparison with three species evolutionarily close to Schistocerca identified splice variants of Para and their relation to those of Drosophila. The anatomical distribution of NaV channels molecularly analogous to those of humans in grasshoppers and vinegar flies provides a substrate for rapid signal propagation and visual processing in the context of visually-guided collision avoidance.
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Affiliation(s)
- Hongxia Wang
- Department of Neuroscience, Baylor College of Medicine, Houston, USA
| | - Bert Foquet
- Department of Entomology, Texas A&M University, College Station, USA
| | - Richard B Dewell
- Department of Neuroscience, Baylor College of Medicine, Houston, USA
| | - Hojun Song
- Department of Entomology, Texas A&M University, College Station, USA
| | - Herman A Dierick
- Department of Neuroscience, Baylor College of Medicine, Houston, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, USA
| | - Fabrizio Gabbiani
- Department of Neuroscience, Baylor College of Medicine, Houston, USA. .,Department of Electrical and Computer Engineering, Rice University, Houston, USA.
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226
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Goodsell DS, Zardecki C, Di Costanzo L, Duarte JM, Hudson BP, Persikova I, Segura J, Shao C, Voigt M, Westbrook JD, Young JY, Burley SK. RCSB Protein Data Bank: Enabling biomedical research and drug discovery. Protein Sci 2020; 29:52-65. [PMID: 31531901 PMCID: PMC6933845 DOI: 10.1002/pro.3730] [Citation(s) in RCA: 186] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022]
Abstract
Analyses of publicly available structural data reveal interesting insights into the impact of the three-dimensional (3D) structures of protein targets important for discovery of new drugs (e.g., G-protein-coupled receptors, voltage-gated ion channels, ligand-gated ion channels, transporters, and E3 ubiquitin ligases). The Protein Data Bank (PDB) archive currently holds > 155,000 atomic-level 3D structures of biomolecules experimentally determined using crystallography, nuclear magnetic resonance spectroscopy, and electron microscopy. The PDB was established in 1971 as the first open-access, digital-data resource in biology, and is now managed by the Worldwide PDB partnership (wwPDB; wwPDB.org). US PDB operations are the responsibility of the Research Collaboratory for Structural Bioinformatics PDB (RCSB PDB). The RCSB PDB serves millions of RCSB.org users worldwide by delivering PDB data integrated with ∼40 external biodata resources, providing rich structural views of fundamental biology, biomedicine, and energy sciences. Recently published work showed that the PDB archival holdings facilitated discovery of ∼90% of the 210 new drugs approved by the US Food and Drug Administration 2010-2016. We review user-driven development of RCSB PDB services, examine growth of the PDB archive in terms of size and complexity, and present examples and opportunities for structure-guided drug discovery for challenging targets (e.g., integral membrane proteins).
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Affiliation(s)
- David S. Goodsell
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
- The Scripps Research InstituteLa JollaCalifornia
| | - Christine Zardecki
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
| | - Luigi Di Costanzo
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
| | - Jose M. Duarte
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, San Diego Supercomputer CenterUniversity of CaliforniaSan DiegoCalifornia
| | - Brian P. Hudson
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
| | - Irina Persikova
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
| | - Joan Segura
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, San Diego Supercomputer CenterUniversity of CaliforniaSan DiegoCalifornia
| | - Chenghua Shao
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
| | - Maria Voigt
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
| | - John D. Westbrook
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
| | - Jasmine Y. Young
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
| | - Stephen K. Burley
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Institute for Quantitative Biomedicine, RutgersThe State University of New JerseyPiscatawayNew Jersey
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, San Diego Supercomputer CenterUniversity of CaliforniaSan DiegoCalifornia
- Rutgers Cancer Institute of New Jersey, RutgersThe State University of New JerseyNew BrunswickNew Jersey
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227
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Tarnovskaya SI, Korkosh VS, Zhorov BS, Frishman D. Predicting novel disease mutations in the cardiac sodium channel. Biochem Biophys Res Commun 2020; 521:603-611. [DOI: 10.1016/j.bbrc.2019.10.142] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 10/20/2019] [Indexed: 12/22/2022]
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228
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Jiang D, Shi H, Tonggu L, Gamal El-Din TM, Lenaeus MJ, Zhao Y, Yoshioka C, Zheng N, Catterall WA. Structure of the Cardiac Sodium Channel. Cell 2019; 180:122-134.e10. [PMID: 31866066 DOI: 10.1016/j.cell.2019.11.041] [Citation(s) in RCA: 201] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/18/2019] [Accepted: 11/27/2019] [Indexed: 12/19/2022]
Abstract
Voltage-gated sodium channel Nav1.5 generates cardiac action potentials and initiates the heartbeat. Here, we report structures of NaV1.5 at 3.2-3.5 Å resolution. NaV1.5 is distinguished from other sodium channels by a unique glycosyl moiety and loss of disulfide-bonding capability at the NaVβ subunit-interaction sites. The antiarrhythmic drug flecainide specifically targets the central cavity of the pore. The voltage sensors are partially activated, and the fast-inactivation gate is partially closed. Activation of the voltage sensor of Domain III allows binding of the isoleucine-phenylalanine-methionine (IFM) motif to the inactivation-gate receptor. Asp and Ala, in the selectivity motif DEKA, line the walls of the ion-selectivity filter, whereas Glu and Lys are in positions to accept and release Na+ ions via a charge-delocalization network. Arrhythmia mutation sites undergo large translocations during gating, providing a potential mechanism for pathogenic effects. Our results provide detailed insights into Nav1.5 structure, pharmacology, activation, inactivation, ion selectivity, and arrhythmias.
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Affiliation(s)
- Daohua Jiang
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Hui Shi
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Lige Tonggu
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | | | - Michael J Lenaeus
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Yan Zhao
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Craig Yoshioka
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
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229
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Eigenbrod O, Debus KY, Reznick J, Bennett NC, Sánchez-Carranza O, Omerbašić D, Hart DW, Barker AJ, Zhong W, Lutermann H, Katandukila JV, Mgode G, Park TJ, Lewin GR. Rapid molecular evolution of pain insensitivity in multiple African rodents. Science 2019; 364:852-859. [PMID: 31147513 DOI: 10.1126/science.aau0236] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 04/25/2019] [Indexed: 12/19/2022]
Abstract
Noxious substances, called algogens, cause pain and are used as defensive weapons by plants and stinging insects. We identified four previously unknown instances of algogen-insensitivity by screening eight African rodent species related to the naked mole-rat with the painful substances capsaicin, acid (hydrogen chloride, pH 3.5), and allyl isothiocyanate (AITC). Using RNA sequencing, we traced the emergence of sequence variants in transduction channels, like transient receptor potential channel TRPA1 and voltage-gated sodium channel Nav1.7, that accompany algogen insensitivity. In addition, the AITC-insensitive highveld mole-rat exhibited overexpression of the leak channel NALCN (sodium leak channel, nonselective), ablating AITC detection by nociceptors. These molecular changes likely rendered highveld mole-rats immune to the stings of the Natal droptail ant. Our study reveals how evolution can be used as a discovery tool to find molecular mechanisms that shut down pain.
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Affiliation(s)
- Ole Eigenbrod
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Karlien Y Debus
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Jane Reznick
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Nigel C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, Republic of South Africa
| | - Oscar Sánchez-Carranza
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Damir Omerbašić
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Daniel W Hart
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, Republic of South Africa
| | - Alison J Barker
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Wei Zhong
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Heike Lutermann
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, Republic of South Africa
| | - Jestina V Katandukila
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, Republic of South Africa.,University of Dar es Salaam, College of Natural and Applied Sciences, Department of Zoology and Wildlife Conservation, P.O. Box 35064, Dar es Salaam, Tanzania
| | - Georgies Mgode
- Pest Management Centre, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Thomas J Park
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany. .,NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
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230
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Denomme N, Hull JM, Mashour GA. Role of Voltage-Gated Sodium Channels in the Mechanism of Ether-Induced Unconsciousness. Pharmacol Rev 2019; 71:450-466. [PMID: 31471460 DOI: 10.1124/pr.118.016592] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Despite continuous clinical use for more than 170 years, the mechanism of general anesthetics has not been completely characterized. In this review, we focus on the role of voltage-gated sodium channels in the sedative-hypnotic actions of halogenated ethers, describing the history of anesthetic mechanisms research, the basic neurobiology and pharmacology of voltage-gated sodium channels, and the evidence for a mechanistic interaction between halogenated ethers and sodium channels in the induction of unconsciousness. We conclude with a more integrative perspective of how voltage-gated sodium channels might provide a critical link between molecular actions of the halogenated ethers and the more distributed network-level effects associated with the anesthetized state across species.
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Affiliation(s)
- Nicholas Denomme
- Departments of Pharmacology (N.D.) and Anesthesiology (G.A.M.), Center for Consciousness Science (N.D., G.A.M.), and Neuroscience Graduate Program (J.M.H., G.A.M.), University of Michigan, Ann Arbor, Michigan
| | - Jacob M Hull
- Departments of Pharmacology (N.D.) and Anesthesiology (G.A.M.), Center for Consciousness Science (N.D., G.A.M.), and Neuroscience Graduate Program (J.M.H., G.A.M.), University of Michigan, Ann Arbor, Michigan
| | - George A Mashour
- Departments of Pharmacology (N.D.) and Anesthesiology (G.A.M.), Center for Consciousness Science (N.D., G.A.M.), and Neuroscience Graduate Program (J.M.H., G.A.M.), University of Michigan, Ann Arbor, Michigan
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231
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Li ZM, Chen LX, Li H. Voltage-gated Sodium Channels and Blockers: An Overview and Where Will They Go? Curr Med Sci 2019; 39:863-873. [PMID: 31845216 DOI: 10.1007/s11596-019-2117-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 09/02/2019] [Indexed: 11/27/2022]
Abstract
Voltage-gated sodium (Nav) channels are critical players in the generation and propagation of action potentials by triggering membrane depolarization. Mutations in Nav channels are associated with a variety of channelopathies, which makes them relevant targets for pharmaceutical intervention. So far, the cryoelectron microscopic structure of the human Nav1.2, Nav1.4, and Nav1.7 has been reported, which sheds light on the molecular basis of functional mechanism of Nav channels and provides a path toward structure-based drug discovery. In this review, we focus on the recent advances in the structure, molecular mechanism and modulation of Nav channels, and state updated sodium channel blockers for the treatment of pathophysiology disorders and briefly discuss where the blockers may be developed in the future.
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Affiliation(s)
- Zhi-Mei Li
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Li-Xia Chen
- Wuya College of Innovation, Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang, 110016, China.
| | - Hua Li
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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232
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Van de Sande DV, Kopljar I, Teisman A, Gallacher DJ, Snyders DJ, Lu HR, Labro AJ. Pharmacological Profile of the Sodium Current in Human Stem Cell-Derived Cardiomyocytes Compares to Heterologous Nav1.5+β1 Model. Front Pharmacol 2019; 10:1374. [PMID: 31920633 PMCID: PMC6917651 DOI: 10.3389/fphar.2019.01374] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 10/29/2019] [Indexed: 12/20/2022] Open
Abstract
The cardiac Nav1.5 mediated sodium current (INa) generates the upstroke of the action potential in atrial and ventricular myocytes. Drugs that modulate this current can therefore be antiarrhythmic or proarrhythmic, which requires preclinical evaluation of their potential drug-induced inhibition or modulation of Nav1.5. Since Nav1.5 assembles with, and is modulated by, the auxiliary β1-subunit, this subunit can also affect the channel’s pharmacological response. To investigate this, the effect of known Nav1.5 inhibitors was compared between COS-7 cells expressing Nav1.5 or Nav1.5+β1 using whole-cell voltage clamp experiments. For the open state class Ia blockers ajmaline and quinidine, and class Ic drug flecainide, the affinity did not differ between both models. For class Ib drugs phenytoin and lidocaine, which are inactivated state blockers, the affinity decreased more than a twofold when β1 was present. Thus, β1 did not influence the affinity for the class Ia and Ic compounds but it did so for the class Ib drugs. Human stem cell-derived cardiomyocytes (hSC-CMs) are a promising translational cell source for in vitro models that express a representative repertoire of channels and auxiliary proteins, including β1. Therefore, we subsequently evaluated the same drugs for their response on the INa in hSC-CMs. Consequently, it was expected and confirmed that the drug response of INa in hSC-CMs compares best to INa expressed by Nav1.5+β1.
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Affiliation(s)
- Dieter V Van de Sande
- Laboratory of Molecular, Cellular, and Network Excitability, University of Antwerp, Antwerp, Belgium
| | - Ivan Kopljar
- Laboratory of Molecular, Cellular, and Network Excitability, University of Antwerp, Antwerp, Belgium.,Global Safety Pharmacology, Non-Clinical Safety, Janssen R&D, Beerse, Belgium
| | - Ard Teisman
- Global Safety Pharmacology, Non-Clinical Safety, Janssen R&D, Beerse, Belgium
| | - David J Gallacher
- Global Safety Pharmacology, Non-Clinical Safety, Janssen R&D, Beerse, Belgium
| | - Dirk J Snyders
- Laboratory of Molecular, Cellular, and Network Excitability, University of Antwerp, Antwerp, Belgium
| | - Hua Rong Lu
- Global Safety Pharmacology, Non-Clinical Safety, Janssen R&D, Beerse, Belgium
| | - Alain J Labro
- Laboratory of Molecular, Cellular, and Network Excitability, University of Antwerp, Antwerp, Belgium
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233
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Dexpramipexole blocks Nav1.8 sodium channels and provides analgesia in multiple nociceptive and neuropathic pain models. Pain 2019; 161:831-841. [DOI: 10.1097/j.pain.0000000000001774] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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234
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Aeby A, Sculier C, Bouza AA, Askar B, Lederer D, Schoonjans A, Vander Ghinst M, Ceulemans B, Offord J, Lopez‐Santiago LF, Isom LL. SCN1B-linked early infantile developmental and epileptic encephalopathy. Ann Clin Transl Neurol 2019; 6:2354-2367. [PMID: 31709768 PMCID: PMC6917350 DOI: 10.1002/acn3.50921] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/22/2019] [Accepted: 09/23/2019] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVE Patients with Early Infantile Epileptic Encephalopathy (EIEE) 52 have inherited, homozygous variants in the gene SCN1B, encoding the voltage-gated sodium channel (VGSC) β1 and β1B non-pore-forming subunits. METHODS Here, we describe the detailed electroclinical features of a biallelic SCN1B patient with a previously unreported variant, p.Arg85Cys. RESULTS The female proband showed hypotonia from birth, multifocal myoclonus at 2.5 months, then focal seizures and myoclonic status epilepticus (SE) at 3 months, triggered by fever. Auditory brainstem response (ABR) showed bilateral hearing loss. Epilepsy was refractory and the patient had virtually no development. Administration of fenfluramine resulted in a significant reduction in seizure frequency and resolution of SE episodes that persisted after a 2-year follow-up. The patient phenotype is more compatible with early infantile developmental and epileptic encephalopathy (DEE) than with typical Dravet syndrome (DS), as previously diagnosed for other patients with homozygous SCN1B variants. Biochemical and electrophysiological analyses of the SCN1B variant expressed in heterologous cells showed cell surface expression of the mutant β1 subunit, similar to wild-type (WT), but with loss of normal β1-mediated modification of human Nav 1.1-generated sodium current, suggesting that SCN1B-p.Arg85Cys is a loss-of-function (LOF) variant. INTERPRETATION Importantly, a review of the literature in light of our results suggests that the term, early infantile developmental and epileptic encephalopathy, is more appropriate than either EIEE or DS to describe biallelic SCN1B patients.
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Affiliation(s)
- Alec Aeby
- Pediatric NeurologyQueen Fabiola Children HospitalULBBrusselsBelgium
| | | | - Alexandra A. Bouza
- Department of PharmacologyUniversity of Michigan Medical SchoolAnn ArborMI48109
| | - Brandon Askar
- Department of PharmacologyUniversity of Michigan Medical SchoolAnn ArborMI48109
| | | | | | - Marc Vander Ghinst
- ENT DepartmentULB‐Hôpital ErasmeUniversité libre de Bruxelles (ULB)BrusselsBelgium
- Laboratoire de Cartographie fonctionnelle du CerveauUNI – ULB Neuroscience InstituteUniversité libre de Bruxelles (ULB)BrusselsBelgium
| | | | - James Offord
- Department of PharmacologyUniversity of Michigan Medical SchoolAnn ArborMI48109
| | | | - Lori L. Isom
- Department of PharmacologyUniversity of Michigan Medical SchoolAnn ArborMI48109
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235
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Zhao Y, Huang G, Wu Q, Wu K, Li R, Lei J, Pan X, Yan N. Cryo-EM structures of apo and antagonist-bound human Ca v3.1. Nature 2019; 576:492-497. [PMID: 31766050 DOI: 10.1038/s41586-019-1801-3] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 11/01/2019] [Indexed: 01/02/2023]
Abstract
Among the ten subtypes of mammalian voltage-gated calcium (Cav) channels, Cav3.1-Cav3.3 constitute the T-type, or the low-voltage-activated, subfamily, the abnormal activities of which are associated with epilepsy, psychiatric disorders and pain1-5. Here we report the cryo-electron microscopy structures of human Cav3.1 alone and in complex with a highly Cav3-selective blocker, Z9446,7, at resolutions of 3.3 Å and 3.1 Å, respectively. The arch-shaped Z944 molecule reclines in the central cavity of the pore domain, with the wide end inserting into the fenestration on the interface between repeats II and III, and the narrow end hanging above the intracellular gate like a plug. The structures provide the framework for comparative investigation of the distinct channel properties of different Cav subfamilies.
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Affiliation(s)
- Yanyu Zhao
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, China
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Gaoxingyu Huang
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Qiurong Wu
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Kun Wu
- Medical Research Center, Beijing Key Laboratory of Cardiopulmonary Cerebral Resuscitation, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Ruiqi Li
- Medical Research Center, Beijing Key Laboratory of Cardiopulmonary Cerebral Resuscitation, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Jianlin Lei
- Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xiaojing Pan
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Nieng Yan
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
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236
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Myotonia in a patient with a mutation in an S4 arginine residue associated with hypokalaemic periodic paralysis and a concomitant synonymous CLCN1 mutation. Sci Rep 2019; 9:17560. [PMID: 31772215 PMCID: PMC6879752 DOI: 10.1038/s41598-019-54041-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 11/05/2019] [Indexed: 12/14/2022] Open
Abstract
The sarcolemmal voltage gated sodium channel NaV1.4 conducts the key depolarizing current that drives the upstroke of the skeletal muscle action potential. It contains four voltage-sensing domains (VSDs) that regulate the opening of the pore domain and ensuing permeation of sodium ions. Mutations that lead to increased NaV1.4 currents are found in patients with myotonia or hyperkalaemic periodic paralysis (HyperPP). Myotonia is also caused by mutations in the CLCN1gene that result in loss-of-function of the skeletal muscle chloride channel ClC-1. Mutations affecting arginine residues in the fourth transmembrane helix (S4) of the NaV1.4 VSDs can result in a leak current through the VSD and hypokalemic periodic paralysis (HypoPP), but these have hitherto not been associated with myotonia. We report a patient with an Nav1.4 S4 arginine mutation, R222Q, presenting with severe myotonia without fulminant paralytic episodes. Other mutations affecting the same residue, R222W and R222G, have been found in patients with HypoPP. We show that R222Q channels have enhanced activation, consistent with myotonia, but also conduct a leak current. The patient carries a concomitant synonymous CLCN1 variant that likely worsens the myotonia and potentially contributes to the amelioration of muscle paralysis. Our data show phenotypic variability for different mutations affecting the same S4 arginine that have implications for clinical therapy.
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237
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Chow CY, Chin YKY, Walker AA, Guo S, Blomster LV, Ward MJ, Herzig V, Rokyta DR, King GF. Venom Peptides with Dual Modulatory Activity on the Voltage-Gated Sodium Channel Na V1.1 Provide Novel Leads for Development of Antiepileptic Drugs. ACS Pharmacol Transl Sci 2019; 3:119-134. [PMID: 32259093 DOI: 10.1021/acsptsci.9b00079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Indexed: 01/14/2023]
Abstract
Voltage-gated sodium (NaV) channels play a fundamental role in normal neurological function, especially via the initiation and propagation of action potentials. The NaV1.1 subtype is found in inhibitory interneurons of the brain and it is essential for maintaining a balance between excitation and inhibition in neuronal networks. Heterozygous loss-of-function mutations of SCN1A, the gene encoding NaV1.1, underlie Dravet syndrome (DS), a severe pediatric epilepsy. We recently demonstrated that selective inhibition of NaV1.1 inactivation prevents seizures and premature death in a mouse model of DS. Thus, selective modulators of NaV1.1 might be useful therapeutics for treatment of DS as they target the underlying molecular deficit. Numerous scorpion-venom peptides have been shown to modulate the activity of NaV channels, but little is known about their activity at NaV1.1. Here we report the isolation, sequence, three-dimensional structure, recombinant production, and functional characterization of two peptidic modulators of NaV1.1 from venom of the buthid scorpion Hottentotta jayakari. These peptides, Hj1a and Hj2a, are potent agonists of NaV1.1 (EC50 of 17 and 32 nM, respectively), and they present dual α/β activity by modifying both the activation and inactivation properties of the channel. NMR studies of rHj1a indicate that it adopts a cystine-stabilized αβ fold similar to known scorpion toxins. Although Hj1a and Hj2a have only limited selectivity for NaV1.1, their unusual dual mode of action provides an alternative approach to the development of selective NaV1.1 modulators for the treatment of DS.
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Affiliation(s)
- Chun Yuen Chow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Yanni K-Y Chin
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andrew A Walker
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Shaodong Guo
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Linda V Blomster
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Micaiah J Ward
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306, United States
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306, United States
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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238
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A structural overview of the ion channels of the TRPM family. Cell Calcium 2019; 85:102111. [PMID: 31812825 DOI: 10.1016/j.ceca.2019.102111] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 12/20/2022]
Abstract
The TRPM (transient receptor potential melastatin) family belongs to the superfamily of TRP cation channels. The TRPM subfamily is composed of eight members that are involved in diverse biological functions such as temperature sensing, inflammation, insulin secretion, and redox sensing. Since the first cloning of TRPM1 in 1998, tremendous progress has been made uncovering the function, structure, and pharmacology of this family. Complete structures of TRPM2, TRPM4, and TRPM8, as well as a partial structure of TRPM7, have been determined by cryo-EM, providing insights into their channel assembly, ion permeation, gating mechanisms, and structural pharmacology. Here we summarize the current knowledge about channel structure, emphasizing general features and principles of the structure of TRPM channels discovered since 2017. We also discuss some of the key unresolved issues in the field, including the molecular mechanisms underlying voltage and temperature dependence, as well as the functions of the TRPM channels' C-terminal domains.
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239
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Maroni M, Körner J, Schüttler J, Winner B, Lampert A, Eberhardt E. β1 and β3 subunits amplify mechanosensitivity of the cardiac voltage-gated sodium channel Nav1.5. Pflugers Arch 2019; 471:1481-1492. [PMID: 31728700 DOI: 10.1007/s00424-019-02324-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 09/25/2019] [Accepted: 10/21/2019] [Indexed: 12/19/2022]
Abstract
In cardiomyocytes, electrical activity is coupled to cellular contraction, thus exposing all proteins expressed in the sarcolemma to mechanical stress. The voltage-gated sodium channel Nav1.5 is the main contributor to the rising phase of the action potential in the heart. There is growing evidence that gating and kinetics of Nav1.5 are modulated by mechanical forces and pathogenic variants that affect mechanosensitivity have been linked to arrhythmias. Recently, the sodium channel β1 subunit has been described to stabilise gating against mechanical stress of Nav1.7 expressed in neurons. Here, we tested the effect of β1 and β3 subunits on mechanosensitivity of the cardiac Nav1.5. β1 amplifies stress-induced shifts of V1/2 of steady-state fast inactivation to hyperpolarised potentials (ΔV1/2: 6.2 mV without and 10.7 mV with β1 co-expression). β3, on the other hand, almost doubles stress-induced speeding of time to sodium current transient peak (Δtime to peak at - 30 mV: 0.19 ms without and 0.37 ms with β3 co-expression). Our findings may indicate that in cardiomyocytes, the interdependence of electrical activity and contraction is used as a means of fine tuning cardiac sodium channel function, allowing quicker but more strongly inactivating sodium currents under conditions of increased mechanical stress. This regulation may help to shorten action potential duration during tachycardia, to prevent re-entry phenomena and thus arrhythmias.
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Affiliation(s)
- Michele Maroni
- Department of Anaesthesiology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany.,Department of Stem Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
| | - Jannis Körner
- Institute of Physiology, Medical Faculty, RWTH Aachen University, 52074, Aachen, Germany.,Department of Anaesthesiology, Medical Faculty, RWTH Aachen University, 52074, Aachen, Germany
| | - Jürgen Schüttler
- Department of Anaesthesiology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
| | - Beate Winner
- Department of Stem Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
| | - Angelika Lampert
- Institute of Physiology, Medical Faculty, RWTH Aachen University, 52074, Aachen, Germany
| | - Esther Eberhardt
- Department of Anaesthesiology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany.
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240
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Barbieri R, Bertelli S, Pusch M, Gavazzo P. Late sodium current blocker GS967 inhibits persistent currents induced by familial hemiplegic migraine type 3 mutations of the SCN1A gene. J Headache Pain 2019; 20:107. [PMID: 31730442 PMCID: PMC6858687 DOI: 10.1186/s10194-019-1056-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/29/2019] [Indexed: 01/31/2023] Open
Abstract
Background Familial hemiplegic migraine (FHM) is a group of genetic migraine, associated with hemiparesis and aura. Three causative different genes have been identified, all of which are involved in membrane ion transport. Among these, SCN1A encodes the voltage-gated Na+ channel Nav1.1, and FHM caused by mutations of SCN1A is named FHM3. For 7 of the 12 known FHM3-causing SCNA1 mutations functional consequences have been investigated, and even if gain of function effect seems to be a predominant phenotype, for several mutations conflicting results have been obtained and the available data do not reveal a univocal FHM3 pathomechanism. Methods To obtain a more complete picture, here, we characterized by patch clamp approach the remaining 5 mutations (Q1489H, I1498M, F1499 L, M1500 V, F1661 L) in heterologous expression systems. Results With the exception of I1498M, all mutants exhibited the same current density as WT and exhibited a shift of the steady state inactivation to more positive voltages, an accelerated recovery from inactivation, and an increase of the persistent current, revealing that most FHM3 mutations induce a gain of function. We also determined the effect of GS967, a late Na+ current blocker, on the above mentioned mutants as well as on previously characterized ones (L1649Q, L1670 W, F1774S). GS967 inhibited persistent currents of all SCNA1 FMH3-related mutants and dramatically slowed the recovery from fast inactivation of WT and mutants, consistent with the hypothesis that GS967 specifically binds to and thereby stabilizes the fast inactivated state. Simulation of neuronal firing showed that enhanced persistent currents cause an increase of ionic fluxes during action potential repolarization and consequent accumulation of K+ and/or exhaustion of neuronal energy resources. In silico application of GS967 largely reduced net ionic currents in neurons without impairing excitability. Conclusion In conclusion, late Na+ current blockers appear a promising specific pharmacological treatment of FHM3.
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Affiliation(s)
- R Barbieri
- Biophysics Institute, National Research Council, Via De Marini 6, Genoa, Italy
| | - S Bertelli
- Biophysics Institute, National Research Council, Via De Marini 6, Genoa, Italy.,International School of Advanced Studies (SISSA), Via Bonomea, 265, Trieste, Italy
| | - M Pusch
- Biophysics Institute, National Research Council, Via De Marini 6, Genoa, Italy
| | - P Gavazzo
- Biophysics Institute, National Research Council, Via De Marini 6, Genoa, Italy.
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241
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Salvage SC, Zhu W, Habib ZF, Hwang SS, Irons JR, Huang CLH, Silva JR, Jackson AP. Gating control of the cardiac sodium channel Nav1.5 by its β3-subunit involves distinct roles for a transmembrane glutamic acid and the extracellular domain. J Biol Chem 2019; 294:19752-19763. [PMID: 31659116 PMCID: PMC6926464 DOI: 10.1074/jbc.ra119.010283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/24/2019] [Indexed: 11/06/2022] Open
Abstract
The auxiliary β3-subunit is an important functional regulator of the cardiac sodium channel Nav1.5, and some β3 mutations predispose individuals to cardiac arrhythmias. The β3-subunit uses its transmembrane α-helix and extracellular domain to bind to Nav1.5. Here, we investigated the role of an unusually located and highly conserved glutamic acid (Glu-176) within the β3 transmembrane region and its potential for functionally synergizing with the β3 extracellular domain (ECD). We substituted Glu-176 with lysine (E176K) in the WT β3-subunit and in a β3-subunit lacking the ECD. Patch-clamp experiments indicated that the E176K substitution does not affect the previously observed β3-dependent depolarizing shift of V½ of steady-state inactivation but does attenuate the accelerated recovery from inactivation conferred by the WT β3-subunit. Removal of the β3-ECD abrogated both the depolarizing shift of steady-state inactivation and the accelerated recovery, irrespective of the presence or absence of the Glu-176 residue. We found that steady-state inactivation and recovery from inactivation involve movements of the S4 helices within the DIII and DIV voltage sensors in response to membrane potential changes. Voltage-clamp fluorometry revealed that the E176K substitution alters DIII voltage sensor dynamics without affecting DIV. In contrast, removal of the ECD significantly altered the dynamics of both DIII and DIV. These results imply distinct roles for the β3-Glu-176 residue and the β3-ECD in regulating the conformational changes of the voltage sensors that determine channel inactivation and recovery from inactivation.
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Affiliation(s)
- Samantha C Salvage
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Wandi Zhu
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130-489
| | - Zaki F Habib
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom.,Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, United Kingdom
| | - Soyon S Hwang
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130-489
| | - Jennifer R Irons
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Christopher L H Huang
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom .,Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, United Kingdom
| | - Jonathan R Silva
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130-489
| | - Antony P Jackson
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
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242
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Mulcahy JV, Pajouhesh H, Beckley JT, Delwig A, Bois JD, Hunter JC. Challenges and Opportunities for Therapeutics Targeting the Voltage-Gated Sodium Channel Isoform Na V1.7. J Med Chem 2019; 62:8695-8710. [PMID: 31012583 PMCID: PMC6786914 DOI: 10.1021/acs.jmedchem.8b01906] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Voltage-gated sodium ion channel subtype 1.7 (NaV1.7) is a high interest target for the discovery of non-opioid analgesics. Compelling evidence from human genetic data, particularly the finding that persons lacking functional NaV1.7 are insensitive to pain, has spurred considerable effort to develop selective inhibitors of this Na+ ion channel target as analgesic medicines. Recent clinical setbacks and disappointing performance of preclinical compounds in animal pain models, however, have led to skepticism around the potential of selective NaV1.7 inhibitors as human therapeutics. In this Perspective, we discuss the attributes and limitations of recently disclosed investigational drugs targeting NaV1.7 and review evidence that, by better understanding the requirements for selectivity and target engagement, the opportunity to deliver effective analgesic medicines targeting NaV1.7 endures.
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Affiliation(s)
- John V. Mulcahy
- SiteOne Therapeutics, 280 Utah Ave, Suite 250, South San Francisco, CA 94080
| | - Hassan Pajouhesh
- SiteOne Therapeutics, 280 Utah Ave, Suite 250, South San Francisco, CA 94080
| | - Jacob T. Beckley
- SiteOne Therapeutics, 351 Evergreen Drive, Suite B1, Bozeman, MT 59715
| | - Anton Delwig
- SiteOne Therapeutics, 280 Utah Ave, Suite 250, South San Francisco, CA 94080
| | - J. Du Bois
- Stanford University, Lokey Chemistry and Biology, 337 Campus Drive, Stanford, CA 94305
| | - John C. Hunter
- SiteOne Therapeutics, 280 Utah Ave, Suite 250, South San Francisco, CA 94080
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243
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Kong DJ, Wang Y, Wang HX, Wang MX, Wang J, Cheng MS. Molecular determinants for ligand binding at Nav1.4 and Nav1.7 channels: Experimental affinity results analyzed by molecular modeling. Comput Biol Chem 2019; 83:107132. [PMID: 31563636 DOI: 10.1016/j.compbiolchem.2019.107132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/11/2019] [Accepted: 09/18/2019] [Indexed: 12/16/2022]
Abstract
Here, we focused on exploring the selectivity mechanism against Nav1.7 over Nav1.4 due to different binding modes of two selected inhibitors. By the superposition of Nav1.7 and Nav1.4 proteins, we selected the most homologous chain of Nav1.7 with Nav1.4, defining the active site of Nav1.4-VSD4 based on the aryl sulfonamide binding site of Nav1.7-VSD4. Comparison of the conformations exhibited by Tyr1386 (Nav1.4) and Tyr1537 (Nav1.7) suggested that the steric hindrance caused by Tyr1386 owned primary influence on inhibition selectivity, which was further verified through molecular docking and MD simulation of two representative inhibitors. Our finding would be helpful for discovery of selective Nav1.7 inhibitors over Nav1.4.
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Affiliation(s)
- De-Jiang Kong
- Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, PR China
| | - Ying Wang
- Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, PR China
| | - Han-Xun Wang
- Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, PR China
| | - Ming-Xing Wang
- Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, PR China
| | - Jian Wang
- Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, PR China.
| | - Mao-Sheng Cheng
- Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, PR China
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244
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White HV, Brown ST, Bozza TC, Raman IM. Effects of FGF14 and Na Vβ4 deletion on transient and resurgent Na current in cerebellar Purkinje neurons. J Gen Physiol 2019; 151:1300-1318. [PMID: 31558566 PMCID: PMC6829560 DOI: 10.1085/jgp.201912390] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 09/03/2019] [Indexed: 11/20/2022] Open
Abstract
Voltage-gated Na channels of Purkinje cells are specialized to maintain high availability during high-frequency repetitive firing. They enter fast-inactivated states relatively slowly and undergo a voltage-dependent open-channel block by an intracellular protein (or proteins) that prevents stable fast inactivation and generates resurgent Na current. These properties depend on the pore-forming α subunits, as well as modulatory subunits within the Na channel complex. The identity of the factors responsible for open-channel block remains a question. Here we investigate the effects of genetic mutation of two Na channel auxiliary subunits highly expressed in Purkinje cells, NaVβ4 and FGF14, on modulating Na channel blocked as well as inactivated states. We find that although both NaVβ4 and the FGF14 splice variant FGF14-1a contain sequences that can generate resurgent-like currents when applied to Na channels in peptide form, deletion of either protein, or both proteins simultaneously, does not eliminate resurgent current in acutely dissociated Purkinje cell bodies. Loss of FGF14 expression does, however, reduce resurgent current amplitude and leads to an acceleration and stabilization of inactivation that is not reversed by application of the site-3 toxin, anemone toxin II (ATX). Tetrodotoxin (TTX) sensitivity is higher for resurgent than transient components of Na current, and loss of FGF14 preferentially affects a highly TTX-sensitive subset of Purkinje α subunits. The data suggest that NaV1.6 channels, which are known to generate the majority of Purkinje cell resurgent current, bind TTX with high affinity and are modulated by FGF14 to facilitate open-channel block.
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Affiliation(s)
- Hayley V White
- Department of Neurobiology, Northwestern University, Evanston, IL.,Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL
| | - Spencer T Brown
- Department of Neurobiology, Northwestern University, Evanston, IL.,Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL
| | - Thomas C Bozza
- Department of Neurobiology, Northwestern University, Evanston, IL.,Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL
| | - Indira M Raman
- Department of Neurobiology, Northwestern University, Evanston, IL .,Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL
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245
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Ciotu CI, Tsantoulas C, Meents J, Lampert A, McMahon SB, Ludwig A, Fischer MJM. Noncanonical Ion Channel Behaviour in Pain. Int J Mol Sci 2019; 20:E4572. [PMID: 31540178 PMCID: PMC6770626 DOI: 10.3390/ijms20184572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 09/09/2019] [Accepted: 09/12/2019] [Indexed: 12/19/2022] Open
Abstract
Ion channels contribute fundamental properties to cell membranes. Although highly diverse in conductivity, structure, location, and function, many of them can be regulated by common mechanisms, such as voltage or (de-)phosphorylation. Primarily considering ion channels involved in the nociceptive system, this review covers more novel and less known features. Accordingly, we outline noncanonical operation of voltage-gated sodium, potassium, transient receptor potential (TRP), and hyperpolarization-activated cyclic nucleotide (HCN)-gated channels. Noncanonical features discussed include properties as a memory for prior voltage and chemical exposure, alternative ion conduction pathways, cluster formation, and silent subunits. Complementary to this main focus, the intention is also to transfer knowledge between fields, which become inevitably more separate due to their size.
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Affiliation(s)
- Cosmin I Ciotu
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | | | - Jannis Meents
- Institute of Physiology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Angelika Lampert
- Institute of Physiology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Stephen B McMahon
- Wolfson Centre for Age-Related Diseases, King's College London, London SE1 1UR, UK
| | - Andreas Ludwig
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Michael J M Fischer
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria.
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246
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Bassetto CAZ, Carvalho-de-Souza JL, Bezanilla F. Metal Bridge in S4 Segment Supports Helix Transition in Shaker Channel. Biophys J 2019; 118:922-933. [PMID: 31635788 DOI: 10.1016/j.bpj.2019.08.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/22/2019] [Accepted: 08/29/2019] [Indexed: 02/05/2023] Open
Abstract
Voltage-gated ion channels play important roles in physiological processes, especially in excitable cells, in which they shape the action potential. In S4-based voltage sensors voltage-gated channels, a common feature is shared; the transmembrane segment 4 (S4) contains positively charged residues intercalated by hydrophobic residues. Although several advances have been made in understating how S4 moves through a hydrophobic plug upon voltage changes, the possible helix transition from α- to 310-helix in S4 during the activation process is still unresolved. Here, we have mutated several hydrophobic residues from I360 to F370 in the S4 segment into histidine, in i, i + 3 and i, i + 6 or i, i + 4 and i, i + 7 pairs, to favor 310- or α-helical conformations, respectively. We have taken advantage of the ability of His to coordinate Zn2+ to promote metal ion bridges, and we have found that the histidine introduced at position 366 (L366H) can interact with the introduced histidine at position 370 (stabilizing that portion of the S4 segment in α-helical conformation). In the presence of 20 μM of Zn2+, the activation currents of L366H:F370H channels were slowed down by a factor of 3.5, and the voltage dependence is shifted by 10 mV toward depolarized potentials with no change on the deactivation time constant. Our data supports that by stabilizing a region of the S4 segment in α-helical conformation, a closed (resting or intermediate) state is stabilized rather than destabilizing the open (active) state. Taken together, our data indicates that S4 undergoes α-helical conformation to a short-lived different secondary structure transiently before reaching the active state in the activation process.
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Affiliation(s)
- Carlos A Z Bassetto
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois
| | | | - Francisco Bezanilla
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois; Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois; Centro Interdisciplinario de Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.
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Myshkin MY, Männikkö R, Krumkacheva OA, Kulbatskii DS, Chugunov AO, Berkut AA, Paramonov AS, Shulepko MA, Fedin MV, Hanna MG, Kullmann DM, Bagryanskaya EG, Arseniev AS, Kirpichnikov MP, Lyukmanova EN, Vassilevski AA, Shenkarev ZO. Cell-Free Expression of Sodium Channel Domains for Pharmacology Studies. Noncanonical Spider Toxin Binding Site in the Second Voltage-Sensing Domain of Human Na v1.4 Channel. Front Pharmacol 2019; 10:953. [PMID: 31555136 PMCID: PMC6737007 DOI: 10.3389/fphar.2019.00953] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/26/2019] [Indexed: 01/06/2023] Open
Abstract
Voltage-gated sodium (NaV) channels are essential for the normal functioning of cardiovascular, muscular, and nervous systems. These channels have modular organization; the central pore domain allows current flow and provides ion selectivity, whereas four peripherally located voltage-sensing domains (VSDs-I/IV) are needed for voltage-dependent gating. Mutations in the S4 voltage-sensing segments of VSDs in the skeletal muscle channel NaV1.4 trigger leak (gating pore) currents and cause hypokalemic and normokalemic periodic paralyses. Previously, we have shown that the gating modifier toxin Hm-3 from the crab spider Heriaeus melloteei binds to the S3-S4 extracellular loop in VSD-I of NaV1.4 channel and inhibits gating pore currents through the channel with mutations in VSD-I. Here, we report that Hm-3 also inhibits gating pore currents through the same channel with the R675G mutation in VSD-II. To investigate the molecular basis of Hm-3 interaction with VSD-II, we produced the corresponding 554-696 fragment of NaV1.4 in a continuous exchange cell-free expression system based on the Escherichia coli S30 extract. We then performed a combined nuclear magnetic resonance (NMR) and electron paramagnetic resonance spectroscopy study of isolated VSD-II in zwitterionic dodecylphosphocholine/lauryldimethylamine-N-oxide or dodecylphosphocholine micelles. To speed up the assignment of backbone resonances, five selectively 13C,15N-labeled VSD-II samples were produced in accordance with specially calculated combinatorial scheme. This labeling approach provides assignment for ∼50% of the backbone. Obtained NMR and electron paramagnetic resonance data revealed correct secondary structure, quasi-native VSD-II fold, and enhanced ps-ns timescale dynamics in the micelle-solubilized domain. We modeled the structure of the VSD-II/Hm-3 complex by protein-protein docking involving binding surfaces mapped by NMR. Hm-3 binds to VSDs I and II using different modes. In VSD-II, the protruding ß-hairpin of Hm-3 interacts with the S1-S2 extracellular loop, and the complex is stabilized by ionic interactions between the positively charged toxin residue K24 and the negatively charged channel residues E604 or D607. We suggest that Hm-3 binding to these charged groups inhibits voltage sensor transition to the activated state and blocks the depolarization-activated gating pore currents. Our results indicate that spider toxins represent a useful hit for periodic paralyses therapy development and may have multiple structurally different binding sites within one NaV molecule.
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Affiliation(s)
- Mikhail Yu Myshkin
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Roope Männikkö
- MRC Centre for Neuromuscular Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | | | - Dmitrii S Kulbatskii
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Anton O Chugunov
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,School of Biological and Medical Physics, Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia.,International Laboratory for Supercomputer Atomistic Modelling and Multi-scale Analysis, National Research University Higher School of Economics, Moscow, Russia
| | - Antonina A Berkut
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexander S Paramonov
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Mikhail A Shulepko
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Matvey V Fedin
- International Tomography Center SB RAS, Novosibirsk, Russia
| | - Michael G Hanna
- MRC Centre for Neuromuscular Diseases, Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Dimitri M Kullmann
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, United Kingdom
| | - Elena G Bagryanskaya
- N.N.Voroztsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk, Russia
| | - Alexander S Arseniev
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,School of Biological and Medical Physics, Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
| | - Mikhail P Kirpichnikov
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Ekaterina N Lyukmanova
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,School of Biological and Medical Physics, Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
| | - Alexander A Vassilevski
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,School of Biological and Medical Physics, Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
| | - Zakhar O Shenkarev
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,School of Biological and Medical Physics, Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
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248
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Finol-Urdaneta RK, McArthur JR, Korkosh VS, Huang S, McMaster D, Glavica R, Tikhonov DB, Zhorov BS, French RJ. Extremely Potent Block of Bacterial Voltage-Gated Sodium Channels by µ-Conotoxin PIIIA. Mar Drugs 2019; 17:md17090510. [PMID: 31470595 PMCID: PMC6780087 DOI: 10.3390/md17090510] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/13/2019] [Accepted: 08/24/2019] [Indexed: 12/15/2022] Open
Abstract
µ-Conotoxin PIIIA, in the sub-picomolar, range inhibits the archetypal bacterial sodium channel NaChBac (NavBh) in a voltage- and use-dependent manner. Peptide µ-conotoxins were first recognized as potent components of the venoms of fish-hunting cone snails that selectively inhibit voltage-gated skeletal muscle sodium channels, thus preventing muscle contraction. Intriguingly, computer simulations predicted that PIIIA binds to prokaryotic channel NavAb with much higher affinity than to fish (and other vertebrates) skeletal muscle sodium channel (Nav 1.4). Here, using whole-cell voltage clamp, we demonstrate that PIIIA inhibits NavBac mediated currents even more potently than predicted. From concentration-response data, with [PIIIA] varying more than 6 orders of magnitude (10−12 to 10−5 M), we estimated an IC50 = ~5 pM, maximal block of 0.95 and a Hill coefficient of 0.81 for the inhibition of peak currents. Inhibition was stronger at depolarized holding potentials and was modulated by the frequency and duration of the stimulation pulses. An important feature of the PIIIA action was acceleration of macroscopic inactivation. Docking of PIIIA in a NaChBac (NavBh) model revealed two interconvertible binding modes. In one mode, PIIIA sterically and electrostatically blocks the permeation pathway. In a second mode, apparent stabilization of the inactivated state was achieved by PIIIA binding between P2 helices and trans-membrane S5s from adjacent channel subunits, partially occluding the outer pore. Together, our experimental and computational results suggest that, besides blocking the channel-mediated currents by directly occluding the conducting pathway, PIIIA may also change the relative populations of conducting (activated) and non-conducting (inactivated) states.
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Affiliation(s)
- Rocio K Finol-Urdaneta
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
- Department of Biochemistry, Brandeis University, Waltham, MA 0254-9110, USA.
| | - Jeffrey R McArthur
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Vyacheslav S Korkosh
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint Petersburg 194223, Russia
| | - Sun Huang
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Denis McMaster
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Robert Glavica
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Denis B Tikhonov
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint Petersburg 194223, Russia
| | - Boris S Zhorov
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint Petersburg 194223, Russia
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 4K1, Canada
| | - Robert J French
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
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249
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Wisedchaisri G, Tonggu L, McCord E, Gamal El-Din TM, Wang L, Zheng N, Catterall WA. Resting-State Structure and Gating Mechanism of a Voltage-Gated Sodium Channel. Cell 2019; 178:993-1003.e12. [PMID: 31353218 PMCID: PMC6688928 DOI: 10.1016/j.cell.2019.06.031] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/06/2019] [Accepted: 06/21/2019] [Indexed: 11/25/2022]
Abstract
Voltage-gated sodium (NaV) channels initiate action potentials in nerve, muscle, and other electrically excitable cells. The structural basis of voltage gating is uncertain because the resting state exists only at deeply negative membrane potentials. To stabilize the resting conformation, we inserted voltage-shifting mutations and introduced a disulfide crosslink in the VS of the ancestral bacterial sodium channel NaVAb. Here, we present a cryo-EM structure of the resting state and a complete voltage-dependent gating mechanism. The S4 segment of the VS is drawn intracellularly, with three gating charges passing through the transmembrane electric field. This movement forms an elbow connecting S4 to the S4-S5 linker, tightens the collar around the S6 activation gate, and prevents its opening. Our structure supports the classical "sliding helix" mechanism of voltage sensing and provides a complete gating mechanism for voltage sensor function, pore opening, and activation-gate closure based on high-resolution structures of a single sodium channel protein.
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Affiliation(s)
| | - Lige Tonggu
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Eedann McCord
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | | | - Liguo Wang
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
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250
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Noncanonical mechanism of voltage sensor coupling to pore revealed by tandem dimers of Shaker. Nat Commun 2019; 10:3584. [PMID: 31395867 PMCID: PMC6687735 DOI: 10.1038/s41467-019-11545-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 07/16/2019] [Indexed: 02/07/2023] Open
Abstract
In voltage-gated potassium channels (VGKC), voltage sensors (VSD) endow voltage-sensitivity to pore domains (PDs) through a not fully understood mechanism. Shaker-like VGKC show domain-swapped configuration: VSD of one subunit is covalently connected to its PD by the protein backbone (far connection) and non-covalently to the PD of the next subunit (near connection). VSD-to-PD coupling is not fully explained by far connection only, therefore an additional mechanistic component may be based on near connection. Using tandem dimers of Shaker channels we show functional data distinguishing VSD-to-PD far from near connections. Near connections influence both voltage-dependence of C-type inactivation at the selectivity filter and overall PD open probability. We speculate a conserved residue in S5 (S412 in Shaker), within van der Waals distance from next subunit S4 residues is key for the noncanonical VSD-to-PD coupling. Natural mutations of S412-homologous residues in brain and heart VGKC are related to neurological and cardiac diseases.
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