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Abreo TJ, Thompson EC, Madabushi A, Soh H, Varghese N, Vanoye CG, Springer K, Park KL, Johnson J, Sims S, Ji Z, Chavez AG, Jankovic MJ, Habte B, Zuberi AR, Lutz C, Wang Z, Krishnan V, Dudler L, Einsele-Scholz S, Noebels JL, George AL, Maheshwari A, Tzingounis AV, Cooper EC. Plural molecular and cellular mechanisms of pore domain KCNQ2 encephalopathy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.04.574177. [PMID: 38260608 PMCID: PMC10802467 DOI: 10.1101/2024.01.04.574177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
KCNQ2 variants in children with neurodevelopmental impairment are difficult to assess due to their heterogeneity and unclear pathogenic mechanisms. We describe a child with neonatal-onset epilepsy, developmental impairment of intermediate severity, and KCNQ2 G256W heterozygosity. Analyzing prior KCNQ2 channel cryoelectron microscopy models revealed G256 as a node of an arch-shaped non-covalent bond network linking S5, the pore turret, and the ion path. Co-expression with G256W dominantly suppressed conduction by wild-type subunits in heterologous cells. Ezogabine partly reversed this suppression. G256W/+ mice have epilepsy leading to premature deaths. Hippocampal CA1 pyramidal cells from G256W/+ brain slices showed hyperexcitability. G256W/+ pyramidal cell KCNQ2 and KCNQ3 immunolabeling was significantly shifted from axon initial segments to neuronal somata. Despite normal mRNA levels, G256W/+ mouse KCNQ2 protein levels were reduced by about 50%. Our findings indicate that G256W pathogenicity results from multiplicative effects, including reductions in intrinsic conduction, subcellular targeting, and protein stability. These studies provide evidence for an unexpected and novel role for the KCNQ2 pore turret and introduce a valid animal model of KCNQ2 encephalopathy. Our results, spanning structure to behavior, may be broadly applicable because the majority of KCNQ2 encephalopathy patients share variants near the selectivity filter.
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Affiliation(s)
- Timothy J. Abreo
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Emma C. Thompson
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Anuraag Madabushi
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Heun Soh
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Nissi Varghese
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Carlos G. Vanoye
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Kristen Springer
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Kristen L. Park
- Department of Pediatrics, Childrens Colorado, University of Colorado, Aurora, CO, USA
- Department of Neurology, Childrens Colorado, University of Colorado, Aurora, CO, USA
| | | | | | - Zhigang Ji
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Ana G. Chavez
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | | | - Bereket Habte
- Department of Pediatrics, Childrens Colorado, University of Colorado, Aurora, CO, USA
- Department of Neurology, Childrens Colorado, University of Colorado, Aurora, CO, USA
| | - Aamir R. Zuberi
- The Rare Disease Translational Center & Technology Evaluation and Development, The Jackson Laboratory, Bar Harbor, ME, USA
| | - Cathleen Lutz
- The Rare Disease Translational Center & Technology Evaluation and Development, The Jackson Laboratory, Bar Harbor, ME, USA
| | - Zhao Wang
- Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
- CryoEM Core, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Vaishnav Krishnan
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Lisa Dudler
- Center for Human Genetics Tübingen, Tübingen, Germany
| | | | - Jeffrey L. Noebels
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Alfred L. George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Atul Maheshwari
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | | | - Edward C. Cooper
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
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Lu A, Kimble M, Justinen S, Morris DP, Wang C, Martinez DE, Hessinger DA. BK Channels Function in Nematocyst Discharge from Vibration-Sensitive Cnidocyte Supporting Cell Complexes of the Sea Anemone Diadumene lineata. THE BIOLOGICAL BULLETIN 2023; 245:88-102. [PMID: 38976849 DOI: 10.1086/730702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
AbstractIntegrated chemo- and mechanosensory pathways, along with activated calcium influxes, regulate nematocyst discharge from sea anemone tentacles. Discharge from vibration-sensitive Type A cnidocyte supporting cell complexes use calcium-conducting transient receptor potential V4-like channels. Because calcium influxes often couple with calcium-activated, large-conductance potassium (BK) channels, we hypothesized that BK channels function in nematocyst discharge. To verify this hypothesis, we first tested five selective BK channel blockers on nematocyst-mediated prey killing in Diadumene lineata (aka Haliplanella luciae). All tested BK channel blockers inhibited prey killing at concentrations comparable to their inhibition of vertebrate BK channels. In addition, the BK channel blocker paxilline selectively inhibited prey killing mediated by vibration-sensitive Type A cnidocyte supporting cell complexes. We queried a mammalian BKα amino acid sequence to the Exaiptasia diaphena database, from which we identified a putative anemone, pore-forming BKα subunit sequence. Using the E. diaphena BKα sequence as a template, we assembled a BKα transcript from our assembled D. lineata transcriptome. In addition, the hydra homolog of D. lineata BKα localizes to nematocytes on the hydra single-cell RNA sequencing map. Our findings suggest that D. lineata expresses BK channels that play a role in vibration-sensitive nematocyst discharge from Type A cnidocyte supporting cell complexes. We believe this is the first functional demonstration of BK channels in nonbilaterians. Because stimulated chemoreceptors frequency tune Type A cnidocyte supporting cell complexes to frequencies matching swimming movements of prey via a protein kinase A signaling pathway and protein kinase A generally activates BK channels, we suggest that D. lineata BK channels may participate in protein kinase A-mediated frequency tuning.
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Kuzmenkov AI, Gigolaev AM, Pinheiro-Junior EL, Peigneur S, Tytgat J, Vassilevski AA. Methionine-isoleucine dichotomy at a key position in scorpion toxins inhibiting voltage-gated potassium channels. Toxicon 2023; 231:107181. [PMID: 37301298 DOI: 10.1016/j.toxicon.2023.107181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/06/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023]
Abstract
Previous studies have identified some key amino acid residues in scorpion toxins blocking potassium channels. In particular, the most numerous toxins belonging to the α-KTx family and affecting voltage-gated potassium channels (KV) present a conserved K-C-X-N motif in the C-terminal half of their sequence. Here, we show that the X position of this motif is almost always occupied by either methionine or isoleucine. We compare the activity of three pairs of peptides that differ just by this residue on a panel of KV1 channels and find that toxins bearing methionine affect preferentially KV1.1 and 1.6 isoforms. The refined K-C-M/I-N motif stands out as the principal structural element of α-KTx conferring high affinity and selectivity to KV channels.
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Affiliation(s)
- Alexey I Kuzmenkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia.
| | - Andrei M Gigolaev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | | | - Steve Peigneur
- Toxicology and Pharmacology, KU Leuven, Leuven, 3000, Belgium
| | - Jan Tytgat
- Toxicology and Pharmacology, KU Leuven, Leuven, 3000, Belgium
| | - Alexander A Vassilevski
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia.
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Hilal I, Khourcha S, Safi A, Hmyene A, Asnawi S, Othman I, Stöcklin R, Oukkache N. Comparative Proteomic Analysis of the Venoms from the Most Dangerous Scorpions in Morocco: Androctonus mauritanicus and Buthus occitanus. Life (Basel) 2023; 13:life13051133. [PMID: 37240778 DOI: 10.3390/life13051133] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/27/2023] [Accepted: 05/03/2023] [Indexed: 05/28/2023] Open
Abstract
Morocco is known to harbor two of the world's most dangerous scorpion species: the black Androctonus mauritanicus (Am) and the yellow Buthus occitanus (Bo), responsible for 83% and 14% of severe envenomation cases, respectively. Scorpion venom is a mixture of biological molecules of variable structures and activities, most of which are proteins of low molecular weights referred to as toxins. In addition to toxins, scorpion venoms also contain biogenic amines, polyamines, and enzymes. With the aim of investigating the composition of the Am and Bo venoms, we conducted an analysis of the venoms by mass spectrometry (ESI-MS) after separation by reversed-phase HPLC chromatography. Results from a total of 19 fractions obtained for the Am venom versus 22 fractions for the Bo venom allowed the identification of approximately 410 and 252 molecular masses, respectively. In both venoms, the most abundant toxins were found to range between 2-5 kDa and 6-8 kDa. This proteomic analysis not only allowed the drawing of an extensive mass fingerprint of the Androctonus mauritanicus and Buthus occitanus venoms but also provided a better insight into the nature of their toxins.
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Affiliation(s)
- Ines Hilal
- Laboratory of Venoms and Toxins, Pasteur Institute of Morocco, Casablanca 20360, Morocco
- Laboratory of Biochemistry, Environment and Food Technology, Faculty of Sciences and Techniques of Mohammedia, Mohammedia 20650, Morocco
| | - Soukaina Khourcha
- Laboratory of Venoms and Toxins, Pasteur Institute of Morocco, Casablanca 20360, Morocco
- Laboratory of Biochemistry, Environment and Food Technology, Faculty of Sciences and Techniques of Mohammedia, Mohammedia 20650, Morocco
| | - Amal Safi
- Laboratory of Biochemistry, Environment and Food Technology, Faculty of Sciences and Techniques of Mohammedia, Mohammedia 20650, Morocco
| | - Abdelaziz Hmyene
- Laboratory of Biochemistry, Environment and Food Technology, Faculty of Sciences and Techniques of Mohammedia, Mohammedia 20650, Morocco
| | - Syafiq Asnawi
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Malaysia
| | - Iekhsan Othman
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Malaysia
| | - Reto Stöcklin
- Atheris Laboratories, Case Postale 314, CH-1233 Bernex, Geneva, Switzerland
| | - Naoual Oukkache
- Laboratory of Venoms and Toxins, Pasteur Institute of Morocco, Casablanca 20360, Morocco
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5
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Mateos DL, Yarov-Yarovoy V. Structural modeling of peptide toxin-ion channel interactions using RosettaDock. Proteins 2023. [PMID: 36729043 DOI: 10.1002/prot.26474] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 12/09/2022] [Accepted: 01/30/2023] [Indexed: 02/03/2023]
Abstract
Voltage-gated ion channels play essential physiological roles in action potential generation and propagation. Peptidic toxins from animal venoms target ion channels and provide useful scaffolds for the rational design of novel channel modulators with enhanced potency and subtype selectivity. Despite recent progress in obtaining experimental structures of peptide toxin-ion channel complexes, structural determination of peptide toxins bound to ion channels in physiologically important states remains challenging. Here we describe an application of RosettaDock approach to the structural modeling of peptide toxins interactions with ion channels. We tested this approach on 10 structures of peptide toxin-ion channel complexes and demonstrated that it can sample near-native structures in all tested cases. Our approach will be useful for improving the understanding of the molecular mechanism of natural peptide toxin modulation of ion channel gating and for the structural modeling of novel peptide-based ion channel modulators.
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Affiliation(s)
- Diego Lopez Mateos
- Department of Physiology and Membrane Biology, University of California Davis, Davis, California, USA.,Biophysics Graduate Group, University of California Davis, Davis, California, USA
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California Davis, Davis, California, USA.,Biophysics Graduate Group, University of California Davis, Davis, California, USA.,Department of Anesthesiology and Pain Medicine, University of California Davis, Davis, California, USA
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Zahra A, Liu R, Han W, Meng H, Wang Q, Wang Y, Campbell SL, Wu J. K Ca-Related Neurological Disorders: Phenotypic Spectrum and Therapeutic Indications. Curr Neuropharmacol 2023; 21:1504-1518. [PMID: 36503451 PMCID: PMC10472807 DOI: 10.2174/1570159x21666221208091805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/21/2022] [Accepted: 07/23/2022] [Indexed: 12/14/2022] Open
Abstract
Although potassium channelopathies have been linked to a wide range of neurological conditions, the underlying pathogenic mechanism is not always clear, and a systematic summary of clinical manifestation is absent. Several neurological disorders have been associated with alterations of calcium-activated potassium channels (KCa channels), such as loss- or gain-of-function mutations, post-transcriptional modification, etc. Here, we outlined the current understanding of the molecular and cellular properties of three subtypes of KCa channels, including big conductance KCa channels (BK), small conductance KCa channels (SK), and the intermediate conductance KCa channels (IK). Next, we comprehensively reviewed the loss- or gain-of-function mutations of each KCa channel and described the corresponding mutation sites in specific diseases to broaden the phenotypic-genotypic spectrum of KCa-related neurological disorders. Moreover, we reviewed the current pharmaceutical strategies targeting KCa channels in KCa-related neurological disorders to provide new directions for drug discovery in anti-seizure medication.
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Affiliation(s)
- Aqeela Zahra
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
- Department of Zoology, University of Sialkot, Sialkot 51310, Pakistan
| | - Ru Liu
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Wenzhe Han
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Hui Meng
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Qun Wang
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - YunFu Wang
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Susan L. Campbell
- Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Jianping Wu
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
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External Hemin as an Inhibitor of Mitochondrial Large-Conductance Calcium-Activated Potassium Channel Activity. Int J Mol Sci 2022; 23:ijms232113391. [DOI: 10.3390/ijms232113391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/26/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial large-conductance calcium-activated potassium channel (mitoBKCa) is located in the inner mitochondrial membrane and seems to play a crucial role in cytoprotection. The mitoBKCa channel is regulated by many modulators, including activators, such as calcium ions and inhibitors, such as heme and its oxidized form hemin. Heme/hemin binds to the heme-binding motif (CXXCH) located between two RCK domains present in the mitochondrial matrix. In the present study, we used the patch-clamp technique in the outside-out configuration to record the activity of mitoBKCa channels. This allowed for the application of channel modulators to the intermembrane-space side of the mitoBKCa. We found that hemin applied in this configuration inhibits the activity of mitoBKCa. In addition, we proved that the observed hemin effect is specific and it is not due to its interaction with the inner mitochondrial membrane. Our data suggest the existence of a new potential heme/hemin binding site in the structure of the mitoBKCa channel located on the mitochondrial intermembrane space side, which could constitute a new way for the regulation of mitoBKCa channel activity.
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Antimicrobial Activity Developed by Scorpion Venoms and Its Peptide Component. Toxins (Basel) 2022; 14:toxins14110740. [PMID: 36355990 PMCID: PMC9693228 DOI: 10.3390/toxins14110740] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/28/2022] [Accepted: 10/23/2022] [Indexed: 01/26/2023] Open
Abstract
Microbial infections represent a problem of great importance at the public health level, with a high rate of morbidity-mortality worldwide. However, treating the different diseases generated by microorganisms requires a gradual increase in acquired resistance when applying or using them against various antibiotic therapies. Resistance is caused by various molecular mechanisms of microorganisms, thus reducing their effectiveness. Consequently, there is a need to search for new opportunities through natural sources with antimicrobial activity. One alternative is using peptides present in different scorpion venoms, specifically from the Buthidae family. Different peptides with biological activity in microorganisms have been characterized as preventing their growth or inhibiting their replication. Therefore, they represent an alternative to be used in the design and development of new-generation antimicrobial drugs in different types of microorganisms, such as bacteria, fungi, viruses, and parasites. Essential aspects for its disclosure, as shown in this review, are the studies carried out on different types of peptides in scorpion venoms with activity against pathogenic microorganisms, highlighting their high therapeutic potential.
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Specificity of Ca 2+-activated K + channel modulation in atherosclerosis and aerobic exercise training. CURRENT TOPICS IN MEMBRANES 2022; 90:123-139. [PMID: 36368871 DOI: 10.1016/bs.ctm.2022.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vascular smooth muscle cells express several isoforms of a number of classes of K+ channels. Potassium channels play critical roles in the regulation of vascular smooth muscle contraction as well as vascular smooth muscle cell proliferation or phenotypic modulation. There is ample evidence that it is Ca2+ that enables these two seemingly disparate functions to be tightly coupled both in healthy and disease processes. Because of the central position that potassium channels have in vasocontraction, vasorelaxation, membrane potential, and smooth muscle cell proliferation, these channels continue to possess the potential to serve as novel therapeutic targets in cardiovascular disease. While there are questions that remain regarding the complete interactions between K+ channels, vascular regulation, smooth muscle cell proliferation, and phenotypic modulation in physiological and pathophysiological conditions, a broad understanding of the contributions of each class of K+ channel to contractile and proliferative states of the vasculature has been reached. This brief review will discuss the current understanding of the role of K+ channels in vascular smooth muscle cells in health and disease using the porcine vascular smooth muscle cell model with particular attention to new scientific discoveries contributed by the authors regarding the effect of endurance exercise on the function of the K+ channels.
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Mellado G, Espinoza N, Garate JA, Neely A. Spider Toxin SNX-482 Gating Modifier Spontaneously Partitions in the Membrane Guided by Electrostatic Interactions. MEMBRANES 2022; 12:membranes12060595. [PMID: 35736302 PMCID: PMC9231009 DOI: 10.3390/membranes12060595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/30/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022]
Abstract
Spider toxin SNX-482 is a cysteine-rich peptide that interferes with calcium channel activity by binding to voltage-sensing domains of the CaV2.3 subtype. Two mechanisms dominate the binding process of cysteine-rich peptides.: direct binding from the aqueous phase or through lateral diffusion from the membrane, the so-called reduction in dimensionality mechanism. In this work, via coarse-grained and atomistic molecular dynamics simulations, we have systematically studied the spontaneous partitioning of SNX-482 with membranes of different anionic compositions and explored via diffusional analysis both binding mechanisms. Our simulations revealed a conserved protein patch that inserts in the membrane, a preference for binding towards partially negatively charged membranes, and that electrostatics guides membrane binding by incrementing and aligning the molecular dipole. Finally, diffusivity calculations showed that the toxin diffusion along the membrane plane is an order of magnitude slower than the aqueous phase suggesting that the critical factor in determining the SNX-482-CaV2.3 binding mechanism is the affinity between the membrane and SNX-482.
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Affiliation(s)
- Guido Mellado
- Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso 2362735, Chile; (G.M.); (N.E.)
- Biofisica y Biología Computacional, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso 2362735, Chile
| | - Nicolas Espinoza
- Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso 2362735, Chile; (G.M.); (N.E.)
- Biofisica y Biología Computacional, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso 2362735, Chile
- Millennium Nucleus in NanoBioPhysics, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso 2360102, Chile
| | - Jose Antonio Garate
- Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso 2362735, Chile; (G.M.); (N.E.)
- Millennium Nucleus in NanoBioPhysics, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso 2360102, Chile
- Centro Científico y Tecnológico de Excelencia Ciencia y Vida, Santiago 7750000, Chile
- Correspondence: (J.A.G.); (A.N.)
| | - Alan Neely
- Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso 2362735, Chile; (G.M.); (N.E.)
- Correspondence: (J.A.G.); (A.N.)
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Zuccolini P, Gavazzo P, Pusch M. BK Channel in the Physiology and in the Cancer of Pancreatic Duct: Impact and Reliability of BK Openers. Front Pharmacol 2022; 13:906608. [PMID: 35685628 PMCID: PMC9171006 DOI: 10.3389/fphar.2022.906608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/10/2022] [Indexed: 11/13/2022] Open
Abstract
BK (KCa 1.1, Slo-1) is a K+ channel characterized by an allosteric regulation of the gating mechanism by Ca2+ binding and voltage, and a high unitary conductance. The channel is expressed in many different tissues, where it is involved in the regulation or the fine-tuning of many physiological processes. Among other organs, BK is expressed in the pancreatic duct, a part of the gland important for the correct ionic composition of the pancreatic juice. Unfortunately, the pancreatic duct is also the site where one of the deadliest cancer types, the pancreatic duct adenocarcinoma (PDAC), develops. In the past years, it has been reported that continuous exposure of cancer cells to BK openers can have a significant impact on cell viability as well as on the ability to proliferate and migrate. Here, we first summarize the main BK channel properties and its roles in pancreatic duct physiology. Then we focus on the potential role of BK as a pharmacological target in PDAC. Moreover, we discuss how results obtained when employing BK activators on cancer cells can, in some cases, be misleading.
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12
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sVmKTx, a transcriptome analysis-based synthetic peptide analogue of Vm24, inhibits Kv1.3 channels of human T cells with improved selectivity. Biochem Pharmacol 2022; 199:115023. [PMID: 35358481 DOI: 10.1016/j.bcp.2022.115023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 12/13/2022]
Abstract
Kv1.3 K+ channels play a central role in the regulation of T cell activation and Ca2+ signaling under physiological and pathophysiological conditions. Peptide toxins targeting Kv1.3 have a significant therapeutic potential in the treatment of autoimmune diseases; thus, the discovery of new toxins is highly motivated. Based on the transcriptome analysis of the venom gland of V. mexicanus smithi a novel synthetic peptide, sVmKTx was generated, containing 36 amino acid residues. sVmKTx shows high sequence similarity to Vm24, a previously characterized peptide from the same species, but contains a Glu at position 32 as opposed to Lys32 in Vm24. Vm24 inhibits Kv1.3 with high affinity (Kd = 2.9 pM). However, it has limited selectivity (~1,500-fold) for Kv1.3 over hKv1.2, hKCa3.1, and mKv1.1. sVmKTx displays reduced Kv1.3 affinity (Kd = 770 pM) but increased selectivity for Kv1.3 over hKv1.2 (~9,000-fold) as compared to Vm24, other channels tested in the panel (hKCa3.1, hKv1.1, hKv1.4, hKv1.5, rKv2.1, hKv11.1, hKCa1.1, hNav1.5) were practically insensitive to the toxin at 2.5 μM. Molecular dynamics simulations showed that introduction of a Glu instead of Lys at position 32 led to a decreased structural fluctuation of the N-terminal segment of sVmKTx, which may explain its increased selectivity for Kv1.3. sVmKTx at 100 nM concentration decreased the expression level of the Ca2+ -dependent T cell activation marker, CD40 ligand. The high affinity block of Kv1.3 and increased selectivity over the natural peptide makes sVmKTx a potential candidate for Kv1.3 blockade-mediated treatment of autoimmune diseases.
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13
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Tazerart S, Blanchard MG, Miranda-Rottmann S, Mitchell DE, Navea Pina B, Thomas CI, Kamasawa N, Araya R. Selective activation of BK channels in small-headed dendritic spines suppresses excitatory postsynaptic potentials. J Physiol 2022; 600:2165-2187. [PMID: 35194785 DOI: 10.1113/jp282303] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 02/14/2022] [Indexed: 12/22/2022] Open
Abstract
Dendritic spines are the main receptacles of excitatory information in the brain. Their particular morphology, with a small head connected to the dendrite by a slender neck, has inspired theoretical and experimental work to understand how these structural features affect the processing, storage and integration of synaptic inputs in pyramidal neurons (PNs). The activation of glutamate receptors in spines triggers a large voltage change as well as calcium signals at the spine head. Thus, voltage-gated and calcium-activated potassium channels located in the spine head likely play a key role in synaptic transmission. Here we study the presence and function of large conductance calcium-activated potassium (BK) channels in spines from layer 5 PNs. We found that BK channels are localized to dendrites and spines regardless of their size, but their activity can only be detected in spines with small head volumes (≤0.09 μm3 ), which reduces the amplitude of two-photon uncaging excitatory postsynaptic potentials recorded at the soma. In addition, we found that calcium signals in spines with small head volumes are significantly larger than those observed in spines with larger head volumes. In accordance with our experimental data, numerical simulations predict that synaptic inputs impinging onto spines with small head volumes generate voltage responses and calcium signals within the spine head itself that are significantly larger than those observed in spines with larger head volumes, which are sufficient to activate spine BK channels. These results show that BK channels are selectively activated in small-headed spines, suggesting a new level of dendritic spine-mediated regulation of synaptic processing, integration and plasticity in cortical PNs. KEY POINTS: BK channels are expressed in the visual cortex and layer 5 pyramidal neuron somata, dendrites and spines regardless of their size. BK channels are selectively activated in small-headed spines (≤0.09 μm3 ), which reduces the amplitude of two-photon (2P) uncaging excitatory postsynaptic potentials (EPSPs) recorded at the soma. Two-photon imaging revealed that intracellular calcium responses in the head of 2P-activated spines are significantly larger in small-headed spines (≤0.09 μm3 ) than in spines with larger head volumes. In accordance with our experimental data, numerical simulations showed that synaptic inputs impinging onto spines with small head volumes (≤0.09 μm3 ) generate voltage responses and calcium signals within the spine head itself that are significantly larger than those observed in spines with larger head volumes, sufficient to activate spine BK channels and suppress EPSPs.
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Affiliation(s)
- Sabrina Tazerart
- Département de Neurosciences, Université de Montréal, Montréal, Canada.,The CHU Sainte-Justine Research Center, Montréal, Canada
| | - Maxime G Blanchard
- Département de Neurosciences, Université de Montréal, Montréal, Canada.,The CHU Sainte-Justine Research Center, Montréal, Canada
| | - Soledad Miranda-Rottmann
- Département de Neurosciences, Université de Montréal, Montréal, Canada.,The CHU Sainte-Justine Research Center, Montréal, Canada
| | - Diana E Mitchell
- Département de Neurosciences, Université de Montréal, Montréal, Canada.,The CHU Sainte-Justine Research Center, Montréal, Canada
| | - Bruno Navea Pina
- Département de Neurosciences, Université de Montréal, Montréal, Canada.,The CHU Sainte-Justine Research Center, Montréal, Canada
| | - Connon I Thomas
- The Imaging Center and Electron Microscopy Core Facility, Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | - Naomi Kamasawa
- The Imaging Center and Electron Microscopy Core Facility, Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | - Roberto Araya
- Département de Neurosciences, Université de Montréal, Montréal, Canada.,The CHU Sainte-Justine Research Center, Montréal, Canada
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14
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Wrzosek A, Gałecka S, Żochowska M, Olszewska A, Kulawiak B. Alternative Targets for Modulators of Mitochondrial Potassium Channels. Molecules 2022; 27:299. [PMID: 35011530 PMCID: PMC8746388 DOI: 10.3390/molecules27010299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial potassium channels control potassium influx into the mitochondrial matrix and thus regulate mitochondrial membrane potential, volume, respiration, and synthesis of reactive oxygen species (ROS). It has been found that pharmacological activation of mitochondrial potassium channels during ischemia/reperfusion (I/R) injury activates cytoprotective mechanisms resulting in increased cell survival. In cancer cells, the inhibition of these channels leads to increased cell death. Therefore, mitochondrial potassium channels are intriguing targets for the development of new pharmacological strategies. In most cases, however, the substances that modulate the mitochondrial potassium channels have a few alternative targets in the cell. This may result in unexpected or unwanted effects induced by these compounds. In our review, we briefly present the various classes of mitochondrial potassium (mitoK) channels and describe the chemical compounds that modulate their activity. We also describe examples of the multidirectional activity of the activators and inhibitors of mitochondrial potassium channels.
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Affiliation(s)
- Antoni Wrzosek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Shur Gałecka
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Monika Żochowska
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Anna Olszewska
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland;
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
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15
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Das B, Saviola AJ, Mukherjee AK. Biochemical and Proteomic Characterization, and Pharmacological Insights of Indian Red Scorpion Venom Toxins. Front Pharmacol 2021; 12:710680. [PMID: 34650430 PMCID: PMC8505525 DOI: 10.3389/fphar.2021.710680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 08/16/2021] [Indexed: 12/16/2022] Open
Abstract
The Indian red scorpion (Mesobuthus tamulus) is one of the world's deadliest scorpions, with stings representing a life-threatening medical emergency. This species is distributed throughout the Indian sub-continent, including eastern Pakistan, eastern Nepal, and Sri Lanka. In India, Indian red scorpions are broadly distributed in western Maharashtra, Saurashtra, Kerala, Andhra Pradesh, Tamil Nadu, and Karnataka; however, fatal envenomations have been recorded primarily in the Konkan region of Maharashtra. The Indian red scorpion venom proteome comprises 110 proteins belonging to 13 venom protein families. The significant pharmacological activity is predominantly caused by the low molecular mass non-enzymatic Na+ and K+ ion channel toxins. Other minor toxins comprise 15.6% of the total venom proteome. Indian red scorpion stings induce the release of catecholamine, which leads to pathophysiological abnormalities in the victim. A strong correlation has been observed between venom proteome composition and local (swelling, redness, heat, and regional lymph node involvement) and systemic (tachycardia, mydriasis, hyperglycemia, hypertension, toxic myocarditis, cardiac failure, and pulmonary edema) manifestations. Immediate administration of antivenom is the preferred treatment for Indian red scorpion stings. However, scorpion-specific antivenoms have exhibited poor immunorecognition and neutralization of the low molecular mass toxins. The proteomic analysis also suggests that Indian red scorpion venom is a rich source of pharmacologically active molecules that may be envisaged as drug prototypes. The following review summarizes the progress made towards understanding the venom proteome of the Indian red scorpion and addresses the current understanding of the pathophysiology associated with its sting.
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Affiliation(s)
- Bhabana Das
- Department of Molecular Biology and Biotechnology, School of Sciences, Tezpur University, Tezpur, India
| | - Anthony J. Saviola
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Ashis K. Mukherjee
- Department of Molecular Biology and Biotechnology, School of Sciences, Tezpur University, Tezpur, India
- Institute of Advanced Study in Science and Technology, Guwahati, India
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16
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Abstract
K+ channels enable potassium to flow across the membrane with great selectivity. There are four K+ channel families: voltage-gated K (Kv), calcium-activated (KCa), inwardly rectifying K (Kir), and two-pore domain potassium (K2P) channels. All four K+ channels are formed by subunits assembling into a classic tetrameric (4x1P = 4P for the Kv, KCa, and Kir channels) or tetramer-like (2x2P = 4P for the K2P channels) architecture. These subunits can either be the same (homomers) or different (heteromers), conferring great diversity to these channels. They share a highly conserved selectivity filter within the pore but show different gating mechanisms adapted for their function. K+ channels play essential roles in controlling neuronal excitability by shaping action potentials, influencing the resting membrane potential, and responding to diverse physicochemical stimuli, such as a voltage change (Kv), intracellular calcium oscillations (KCa), cellular mediators (Kir), or temperature (K2P).
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17
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Matsumura K, Yokogawa M, Osawa M. Peptide Toxins Targeting KV Channels. Handb Exp Pharmacol 2021; 267:481-505. [PMID: 34117930 DOI: 10.1007/164_2021_500] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
A number of peptide toxins isolated from animals target potassium ion (K+) channels. Many of them are particularly known to inhibit voltage-gated K+ (KV) channels and are mainly classified into pore-blocking toxins or gating-modifier toxins. Pore-blocking toxins directly bind to the ion permeation pores of KV channels, thereby physically occluding them. In contrast, gating-modifier toxins bind to the voltage-sensor domains of KV channels, modulating their voltage-dependent conformational changes. These peptide toxins are useful molecular tools in revealing the structure-function relationship of KV channels and have potential for novel treatments for diseases related to KV channels. This review focuses on the inhibition mechanism of pore-blocking and gating-modifier toxins that target KV channels.
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Affiliation(s)
- Kazuki Matsumura
- Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
| | - Mariko Yokogawa
- Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan
| | - Masanori Osawa
- Graduate School of Pharmaceutical Sciences, Keio University, Tokyo, Japan.
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18
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Tabakmakher VM, Kuzmenkov AI, Gigolaev AM, Pinheiro-Junior EL, Peigneur S, Efremov RG, Tytgat J, Vassilevski AA. Artificial Peptide Ligand of Potassium
Channel KV1.1 with High Selectivity. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021020186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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19
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Abstract
Potassium channels are the most diverse and ubiquitous family of ion channels found in cells. The Ca2+ and voltage gated members form a subfamily that play a variety of roles in both excitable and non-excitable cells and are further classified on the basis of their single channel conductance to form the small conductance (SK), intermediate conductance (IK) and big conductance (BK) K+ channels.In this chapter, we will focus on the mechanisms underlying the gating of BK channels, whose function is modified in different tissues by different splice variants as well as the expanding array of regulatory accessory subunits including β, γ and LINGO subunits. We will examine how BK channels are modified by these regulatory subunits and describe how the channel gating is altered by voltage and Ca2+ whilst setting this in context with the recently published structures of the BK channel. Finally, we will discuss how BK and other calcium-activated channels are modulated by novel ion channel modulators and describe some of the challenges associated with trying to develop compounds with sufficient efficacy, potency and selectivity to be of therapeutic benefit.
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20
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Weisbrod D. Small and Intermediate Calcium Activated Potassium Channels in the Heart: Role and Strategies in the Treatment of Cardiovascular Diseases. Front Physiol 2020; 11:590534. [PMID: 33329039 PMCID: PMC7719780 DOI: 10.3389/fphys.2020.590534] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 10/02/2020] [Indexed: 12/11/2022] Open
Abstract
Calcium-activated potassium channels are a heterogeneous family of channels that, despite their different biophysical characteristics, structures, and pharmacological signatures, play a role of transducer between the ubiquitous intracellular calcium signaling and the electric variations of the membrane. Although this family of channels was extensively described in various excitable and non-excitable tissues, an increasing amount of evidences shows their functional role in the heart. This review aims to focus on the physiological role and the contribution of the small and intermediate calcium-activated potassium channels in cardiac pathologies.
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21
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Szteyn K, Singh H. BK Ca Channels as Targets for Cardioprotection. Antioxidants (Basel) 2020; 9:antiox9080760. [PMID: 32824463 PMCID: PMC7463653 DOI: 10.3390/antiox9080760] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/09/2020] [Accepted: 08/13/2020] [Indexed: 12/16/2022] Open
Abstract
The large-conductance calcium- and voltage-activated K+ channel (BKCa) are encoded by the Kcnma1 gene. They are ubiquitously expressed in neuronal, smooth muscle, astrocytes, and neuroendocrine cells where they are known to play an important role in physiological and pathological processes. They are usually localized to the plasma membrane of the majority of the cells with an exception of adult cardiomyocytes, where BKCa is known to localize to mitochondria. BKCa channels couple calcium and voltage responses in the cell, which places them as unique targets for a rapid physiological response. The expression and activity of BKCa have been linked to several cardiovascular, muscular, and neurological defects, making them a key therapeutic target. Specifically in the heart muscle, pharmacological and genetic activation of BKCa channels protect the heart from ischemia-reperfusion injury and also facilitate cardioprotection rendered by ischemic preconditioning. The mechanism involved in cardioprotection is assigned to the modulation of mitochondrial functions, such as regulation of mitochondrial calcium, reactive oxygen species, and membrane potential. Here, we review the progress made on BKCa channels and cardioprotection and explore their potential roles as therapeutic targets for preventing acute myocardial infarction.
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22
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Abstract
Ca2+- and voltage-gated K+ channels of large conductance (BK channels) are expressed in a diverse variety of both excitable and inexcitable cells, with functional properties presumably uniquely calibrated for the cells in which they are found. Although some diversity in BK channel function, localization, and regulation apparently arises from cell-specific alternative splice variants of the single pore-forming α subunit ( KCa1.1, Kcnma1, Slo1) gene, two families of regulatory subunits, β and γ, define BK channels that span a diverse range of functional properties. We are just beginning to unravel the cell-specific, physiological roles served by BK channels of different subunit composition.
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Affiliation(s)
- Vivian Gonzalez-Perez
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
| | - Christopher J Lingle
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
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23
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Papp F, Hajdu P, Tajti G, Toth A, Nagy E, Fazekas Z, Kovacs S, Vámosi G, Varga Z, Panyi G. Periodic Membrane Potential and Ca 2+ Oscillations in T Cells Forming an Immune Synapse. Int J Mol Sci 2020; 21:ijms21051568. [PMID: 32106594 PMCID: PMC7084896 DOI: 10.3390/ijms21051568] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/17/2020] [Accepted: 02/19/2020] [Indexed: 11/25/2022] Open
Abstract
The immunological synapse (IS) is a specialized contact area formed between a T cell and an antigen presenting cell (APC). Besides molecules directly involved in antigen recognition such as the TCR/CD3 complex, ion channels important in the membrane potential and intracellular free Ca2+ concentration control of T cells are also recruited into the IS. These are the voltage-gated Kv1.3 and Ca2+-activated KCa3.1 K+ channels and the calcium release-activated Ca2+ channel (CRAC). However, the consequence of this recruitment on membrane potential and Ca2+ level control is not known. Here we demonstrate that the membrane potential (MP) of murine T cells conjugated with APCs in an IS shows characteristic oscillations. We found that depolarization of the membrane by current injection or by increased extracellular K+ concentration produced membrane potential oscillations (MPO) significantly more frequently in conjugated T cells than in lone T cells. Furthermore, oscillation of the free intracellular Ca2+ concentration could also be observed more frequently in cells forming an IS than in lone cells. We suggest that in the IS the special arrangement of channels and the constrained space between the interacting cells creates a favorable environment for these oscillations, which may enhance the signaling process leading to T cell activation.
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Affiliation(s)
- Ferenc Papp
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (F.P.); (G.T.); (A.T.); (E.N.); (Z.F.); (G.V.); (Z.V.)
| | - Peter Hajdu
- Department of Biophysics and Cell Biology, Faculty of Dentistry, University of Debrecen, H-4032 Debrecen, Hungary;
| | - Gabor Tajti
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (F.P.); (G.T.); (A.T.); (E.N.); (Z.F.); (G.V.); (Z.V.)
| | - Agnes Toth
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (F.P.); (G.T.); (A.T.); (E.N.); (Z.F.); (G.V.); (Z.V.)
| | - Eva Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (F.P.); (G.T.); (A.T.); (E.N.); (Z.F.); (G.V.); (Z.V.)
| | - Zsolt Fazekas
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (F.P.); (G.T.); (A.T.); (E.N.); (Z.F.); (G.V.); (Z.V.)
| | - Sandor Kovacs
- Institute of Sectoral Economics and Methodology, Faculty of Economics and Business, Department of Statistics and Research Methodology, University of Debrecen, 4032 Debrecen, Hungary;
| | - György Vámosi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (F.P.); (G.T.); (A.T.); (E.N.); (Z.F.); (G.V.); (Z.V.)
| | - Zoltan Varga
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (F.P.); (G.T.); (A.T.); (E.N.); (Z.F.); (G.V.); (Z.V.)
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (F.P.); (G.T.); (A.T.); (E.N.); (Z.F.); (G.V.); (Z.V.)
- Correspondence: ; Tel.: +36-52-258-603
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24
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Manoury B, Idres S, Leblais V, Fischmeister R. Ion channels as effectors of cyclic nucleotide pathways: Functional relevance for arterial tone regulation. Pharmacol Ther 2020; 209:107499. [PMID: 32068004 DOI: 10.1016/j.pharmthera.2020.107499] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 02/05/2020] [Indexed: 02/07/2023]
Abstract
Numerous mediators and drugs regulate blood flow or arterial pressure by acting on vascular tone, involving cyclic nucleotide intracellular pathways. These signals lead to regulation of several cellular effectors, including ion channels that tune cell membrane potential, Ca2+ influx and vascular tone. The characterization of these vasocontrictive or vasodilating mechanisms has grown in complexity due to i) the variety of ion channels that are expressed in both vascular endothelial and smooth muscle cells, ii) the heterogeneity of responses among the various vascular beds, and iii) the number of molecular mechanisms involved in cyclic nucleotide signalling in health and disease. This review synthesizes key data from literature that highlight ion channels as physiologically relevant effectors of cyclic nucleotide pathways in the vasculature, including the characterization of the molecular mechanisms involved. In smooth muscle cells, cation influx or chloride efflux through ion channels are associated with vasoconstriction, whereas K+ efflux repolarizes the cell membrane potential and mediates vasodilatation. Both categories of ion currents are under the influence of cAMP and cGMP pathways. Evidence that some ion channels are influenced by CN signalling in endothelial cells will also be presented. Emphasis will also be put on recent data touching a variety of determinants such as phosphodiesterases, EPAC and kinase anchoring, that complicate or even challenge former paradigms.
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Affiliation(s)
- Boris Manoury
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France.
| | - Sarah Idres
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
| | - Véronique Leblais
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
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25
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Liu X, Tao J, Zhang S, Lan W, Wang C, Ji Y, Cao C. Selective Blockade of Neuronal BK (α + β4) Channels Preventing Epileptic Seizure. J Med Chem 2019; 63:216-230. [DOI: 10.1021/acs.jmedchem.9b01241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Xinlian Liu
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
- University of Chinese Academy of Science, No. 19A, Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Jie Tao
- Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, 164 Lanxi Road, Putuo District, Shanghai 200062, China
- Institute of Biomembrane and Biopharmaceutics, Shanghai University, 99 Shangda Road,
BaoShan District, Shanghai 200444, China
| | - Shuzhang Zhang
- Institute of Biomembrane and Biopharmaceutics, Shanghai University, 99 Shangda Road,
BaoShan District, Shanghai 200444, China
| | - Wenxian Lan
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Chunxi Wang
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Yonghua Ji
- Institute of Biomembrane and Biopharmaceutics, Shanghai University, 99 Shangda Road,
BaoShan District, Shanghai 200444, China
- Xinhua Hospital (Chongming) Affiliated to Shanghai JiaoTong University School of Medicine, Shanghai Chongming Xinhua Translational Medical Institute for Cancer Pain, 25 Nanmen Port Street, Chongming Branch, Shanghai 202150, China
| | - Chunyang Cao
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
- University of Chinese Academy of Science, No. 19A, Yuquan Road, Shijingshan District, Beijing 100049, China
- Institute of Drug Discovery Technology, Ningbo University, No 818 Fenghua Road, Ningbo, Zhejiang 313211, China
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26
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Anti-tumoral effect of scorpion peptides: Emerging new cellular targets and signaling pathways. Cell Calcium 2019; 80:160-174. [DOI: 10.1016/j.ceca.2019.05.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/10/2019] [Accepted: 05/10/2019] [Indexed: 12/31/2022]
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27
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Zhao Y, Chen Z, Cao Z, Li W, Wu Y. Diverse Structural Features of Potassium Channels Characterized by Scorpion Toxins as Molecular Probes. Molecules 2019; 24:molecules24112045. [PMID: 31146335 PMCID: PMC6600638 DOI: 10.3390/molecules24112045] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/15/2019] [Accepted: 05/26/2019] [Indexed: 12/21/2022] Open
Abstract
Scorpion toxins are well-known as the largest potassium channel peptide blocker family. They have been successfully proven to be valuable molecular probes for structural research on diverse potassium channels. The potassium channel pore region, including the turret and filter regions, is the binding interface for scorpion toxins, and structural features from different potassium channels have been identified using different scorpion toxins. According to the spatial orientation of channel turrets with differential sequence lengths and identities, conformational changes and molecular surface properties, the potassium channel turrets can be divided into the following three states: open state with less hindering effects on toxin binding, half-open state or half-closed state with certain effects on toxin binding, and closed state with remarkable effects on toxin binding. In this review, we summarized the diverse structural features of potassium channels explored using scorpion toxin tools and discuss future work in the field of scorpion toxin-potassium channel interactions.
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Affiliation(s)
- Yonghui Zhao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
| | - Zongyun Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China.
| | - Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
- Biodrug Research Center, Wuhan University, Wuhan 430072, China.
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
- Biodrug Research Center, Wuhan University, Wuhan 430072, China.
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
- Biodrug Research Center, Wuhan University, Wuhan 430072, China.
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28
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Abstract
Ca2+- and voltage-gated K+ channels of large conductance (BK channels) are expressed in a diverse variety of both excitable and inexcitable cells, with functional properties presumably uniquely calibrated for the cells in which they are found. Although some diversity in BK channel function, localization, and regulation apparently arises from cell-specific alternative splice variants of the single pore-forming α subunit ( KCa1.1, Kcnma1, Slo1) gene, two families of regulatory subunits, β and γ, define BK channels that span a diverse range of functional properties. We are just beginning to unravel the cell-specific, physiological roles served by BK channels of different subunit composition.
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Affiliation(s)
- Vivian Gonzalez-Perez
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
| | - Christopher J Lingle
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
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Imura N, Ae M, Hoshino R, Abe M, Yamamuro T, Oyama K, Oyama Y. Membrane hyperpolarization and depolarization of rat thymocytes by azoxystrobin, a post harvest fungicide. Chem Biol Interact 2019; 300:35-39. [DOI: 10.1016/j.cbi.2019.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/30/2018] [Accepted: 01/06/2019] [Indexed: 12/18/2022]
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Yu Y, Hu B, Bao J, Mulvany J, Bielefeld E, Harrison RT, Neton SA, Thirumala P, Chen Y, Lei D, Qiu Z, Zheng Q, Ren J, Perez-Flores MC, Yamoah EN, Salehi P. Otoprotective Effects of Stephania tetrandra S. Moore Herb Isolate against Acoustic Trauma. J Assoc Res Otolaryngol 2018; 19:653-668. [PMID: 30187298 PMCID: PMC6249158 DOI: 10.1007/s10162-018-00690-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 07/08/2018] [Indexed: 01/10/2023] Open
Abstract
Noise is the most common occupational and environmental hazard, and noise-induced hearing loss (NIHL) is the second most common form of sensorineural hearing deficit. Although therapeutics that target the free-radical pathway have shown promise, none of these compounds is currently approved against NIHL by the United States Food and Drug Administration. The present study has demonstrated that tetrandrine (TET), a traditional Chinese medicinal alkaloid and the main chemical isolate of the Stephania tetrandra S. Moore herb, significantly attenuated NIHL in CBA/CaJ mice. TET is known to exert antihypertensive and antiarrhythmic effects through the blocking of calcium channels. Whole-cell patch-clamp recording from adult spiral ganglion neurons showed that TET blocked the transient Ca2+ current in a dose-dependent manner and the half-blocking concentration was 0.6 + 0.1 μM. Consistent with previous findings that modulations of calcium-based signaling pathways have both prophylactic and therapeutic effects against neural trauma, NIHL was significantly diminished by TET administration. Importantly, TET has a long-lasting protective effect after noise exposure (48 weeks) in comparison to 2 weeks after noise exposure. The otoprotective effects of TET were achieved mainly by preventing outer hair cell damage and synapse loss between inner hair cells and spiral ganglion neurons. Thus, our data indicate that TET has great potential in the prevention and treatment of NIHL.
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Affiliation(s)
- Yan Yu
- The First People’s Hospital of Zhangjiagang, 68 W Jiyang Road, Zhangjiagang City, 215600 Jiangsu China
- Translational Research Center, Northeast Ohio Medical University, Rootstown, OH 44272 USA
| | - Bing Hu
- Translational Research Center, Northeast Ohio Medical University, Rootstown, OH 44272 USA
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH 44106 USA
- Department of Otolaryngology Head and Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, 440011 Hunan China
| | - Jianxin Bao
- Translational Research Center, Northeast Ohio Medical University, Rootstown, OH 44272 USA
- Department of Research and Development, Gateway Biotechnology Inc., Rootstown, OH 44272 USA
| | - Jessica Mulvany
- Translational Research Center, Northeast Ohio Medical University, Rootstown, OH 44272 USA
- Department of Research and Development, Gateway Biotechnology Inc., Rootstown, OH 44272 USA
| | - Eric Bielefeld
- Department of Speech and Hearing Science, Ohio State University, Columbus, OH 43210 USA
| | - Ryan T. Harrison
- Department of Speech and Hearing Science, Ohio State University, Columbus, OH 43210 USA
| | - Sarah A. Neton
- Department of Speech and Hearing Science, Ohio State University, Columbus, OH 43210 USA
| | - Partha Thirumala
- The University of Pittsburgh Medical Center, Suite B-400, 200 Lothrop Street, Pittsburgh, PA 15213 USA
| | - Yingying Chen
- Translational Research Center, Northeast Ohio Medical University, Rootstown, OH 44272 USA
| | - Debin Lei
- Translational Research Center, Northeast Ohio Medical University, Rootstown, OH 44272 USA
| | - Ziyu Qiu
- Department of Research and Development, Gateway Biotechnology Inc., Rootstown, OH 44272 USA
| | - Qingyin Zheng
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH 44106 USA
| | - Jihao Ren
- Department of Otolaryngology Head and Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, 440011 Hunan China
| | - Maria Cristina Perez-Flores
- Department of Physiology and Cell Biology, University of Nevada Reno, 1664 North Virginia St, Reno, NV 89557 USA
| | - Ebenezer N. Yamoah
- Department of Physiology and Cell Biology, University of Nevada Reno, 1664 North Virginia St, Reno, NV 89557 USA
| | - Pezhman Salehi
- Translational Research Center, Northeast Ohio Medical University, Rootstown, OH 44272 USA
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Ikeda K, Suzuki N, Bekkers JM. Sodium and potassium conductances in principal neurons of the mouse piriform cortex: a quantitative description. J Physiol 2018; 596:5397-5414. [PMID: 30194865 DOI: 10.1113/jp275824] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 08/21/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The primary olfactory (or piriform) cortex is a promising model system for understanding how the cerebral cortex processes sensory information, although an investigation of the piriform cortex is hindered by a lack of detailed information about the intrinsic electrical properties of its component neurons. In the present study, we quantify the properties of voltage-dependent sodium currents and voltage- and calcium-dependent potassium currents in two important classes of excitatory neurons in the main input layer of the piriform cortex. We identify several classes of these currents and show that their properties are similar to those found in better-studied cortical regions. Our detailed quantitative descriptions of these currents will be valuable to computational neuroscientists who aim to build models that explain how the piriform cortex encodes odours. ABSTRACT The primary olfactory cortex (or piriform cortex, PC) is an anatomically simple palaeocortex that is increasingly used as a model system for investigating cortical sensory processing. However, little information is available on the intrinsic electrical conductances in neurons of the PC, hampering efforts to build realistic computational models of this cortex. In the present study, we used nucleated macropatches and whole-cell recordings to rigorously quantify the biophysical properties of voltage-gated sodium (NaV ), voltage-gated potassium (KV ) and calcium-activated potassium (KCa ) conductances in two major classes of glutamatergic neurons in layer 2 of the PC, semilunar (SL) cells and superficial pyramidal (SP) cells. We found that SL and SP cells both express a fast-inactivating NaV current, two types of KV current (A-type and delayed rectifier-type) and three types of KCa current (fast-, medium- and slow-afterhyperpolarization currents). The kinetic and voltage-dependent properties of the NaV and KV conductances were, with some exceptions, identical in SL and SP cells and similar to those found in neocortical pyramidal neurons. The KCa conductances were also similar across the different types of neurons. Our results are summarized in a series of empirical equations that should prove useful to computational neuroscientists seeking to model the PC. More broadly, our findings indicate that, at the level of single-cell electrical properties, this palaeocortex is not so different from the neocortex, vindicating efforts to use the PC as a model of cortical sensory processing in general.
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Affiliation(s)
- Kaori Ikeda
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | | | - John M Bekkers
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
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Activation of galanin receptor 1 inhibits locus coeruleus neurons via GIRK channels. Biochem Biophys Res Commun 2018; 503:79-85. [DOI: 10.1016/j.bbrc.2018.05.181] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 05/26/2018] [Indexed: 01/15/2023]
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33
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Ortiz E, Possani LD. Scorpion toxins to unravel the conundrum of ion channel structure and functioning. Toxicon 2018; 150:17-27. [DOI: 10.1016/j.toxicon.2018.04.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/24/2018] [Accepted: 04/29/2018] [Indexed: 01/11/2023]
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Inoue M, Matsuoka H, Lesage F, Harada K. Lack of p11 expression facilitates acidity‐sensing function of TASK1 channels in mouse adrenal medullary cells. FASEB J 2018; 33:455-468. [DOI: 10.1096/fj.201800407rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Masumi Inoue
- Department of Cell and Systems PhysiologySchool of MedicineUniversity of Occupational and Environmental Health Kitakyushu Japan
| | - Hidetada Matsuoka
- Department of Cell and Systems PhysiologySchool of MedicineUniversity of Occupational and Environmental Health Kitakyushu Japan
| | - Florian Lesage
- Université Côte d'AzurINSERMCentre National de la Recherche Scientifique (CNRS)Institut de Pharmacologie Moléculaire et CellulaireLaboratory of Excellence in Ion Channel Science and Therapeutics (LabEx ICST) Valbonne France
| | - Keita Harada
- Department of Cell and Systems PhysiologySchool of MedicineUniversity of Occupational and Environmental Health Kitakyushu Japan
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Tiwari MN, Mohan S, Biala Y, Yaari Y. Differential contributions of Ca 2+ -activated K + channels and Na + /K + -ATPases to the generation of the slow afterhyperpolarization in CA1 pyramidal cells. Hippocampus 2018; 28:338-357. [PMID: 29431274 PMCID: PMC5947627 DOI: 10.1002/hipo.22836] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/17/2017] [Accepted: 02/05/2018] [Indexed: 12/13/2022]
Abstract
In many types of CNS neurons, repetitive spiking produces a slow afterhyperpolarization (sAHP), providing sustained, intrinsically generated negative feedback to neuronal excitation. Changes in the sAHP have been implicated in learning behaviors, in cognitive decline in aging, and in epileptogenesis. Despite its importance in brain function, the mechanisms generating the sAHP are still controversial. Here we have addressed the roles of M-type K+ current (IM ), Ca2+ -gated K+ currents (ICa(K) 's) and Na+ /K+ -ATPases (NKAs) current to sAHP generation in adult rat CA1 pyramidal cells maintained at near-physiological temperature (35 °C). No evidence for IM contribution to the sAHP was found in these neurons. Both ICa(K) 's and NKA current contributed to sAHP generation, the latter being the predominant generator of the sAHP, particularly when evoked with short trains of spikes. Of the different NKA isoenzymes, α1 -NKA played the key role, endowing the sAHP a steep voltage-dependence. Thus normal and pathological changes in α1 -NKA expression or function may affect cognitive processes by modulating the inhibitory efficacy of the sAHP.
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Affiliation(s)
- Manindra Nath Tiwari
- Department of Medical Neurobiology; Institute for Medical Research Israel‐CanadaThe Hebrew University‐Hadassah School of MedicineJerusalem91120Israel
| | - Sandesh Mohan
- Department of Medical Neurobiology; Institute for Medical Research Israel‐CanadaThe Hebrew University‐Hadassah School of MedicineJerusalem91120Israel
| | - Yoav Biala
- Department of Medical Neurobiology; Institute for Medical Research Israel‐CanadaThe Hebrew University‐Hadassah School of MedicineJerusalem91120Israel
| | - Yoel Yaari
- Department of Medical Neurobiology; Institute for Medical Research Israel‐CanadaThe Hebrew University‐Hadassah School of MedicineJerusalem91120Israel
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36
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Wang Y, Lan W, Yan Z, Gao J, Liu X, Wang S, Guo X, Wang C, Zhou H, Ding J, Cao C. Solution structure of extracellular loop of human β4 subunit of BK channel and its biological implication on ChTX sensitivity. Sci Rep 2018; 8:4571. [PMID: 29545539 PMCID: PMC5854672 DOI: 10.1038/s41598-018-23016-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 03/05/2018] [Indexed: 01/06/2023] Open
Abstract
Large-conductance Ca2+- and voltage-dependent K+ (BK) channels display diverse biological functions while their pore-forming α subunit is coded by a single Slo1 gene. The variety of BK channels is correlated with the effects of BKα coexpression with auxiliary β (β1-β4) subunits, as well as newly defined γ subunits. Charybdotoxin (ChTX) blocks BK channel through physically occluding the K+-conduction pore. Human brain enriched β4 subunit (hβ4) alters the conductance-voltage curve, slows activation and deactivation time courses of BK channels. Its extracellular loop (hβ4-loop) specifically impedes ChTX to bind BK channel pore. However, the structure of β4 subunit's extracellular loop and the molecular mechanism for gating kinetics, toxin sensitivity of BK channels regulated by β4 are still unclear. To address them, here, we first identified four disulfide bonds in hβ4-loop by mass spectroscopy and NMR techniques. Then we determined its three-dimensional solution structure, performed NMR titration and electrophysiological analysis, and found that residue Asn123 of β4 subunit regulated the gating and pharmacological characteristics of BK channel. Finally, by constructing structure models of BKα/β4 and thermodynamic double-mutant cycle analysis, we proposed that BKα subunit might interact with β4 subunit through the conserved residue Glu264(BKα) coupling with residue Asn123(β4).
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Affiliation(s)
- Yanting Wang
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), 345 Lingling Road, Shanghai, 200032, China.,Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, Hubei, China
| | - Wenxian Lan
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), 345 Lingling Road, Shanghai, 200032, China
| | - Zhenzhen Yan
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, Hubei, China
| | - Jing Gao
- Department of Analytical Chemistry, Shanghai Institute of Materia Medica, CAS, 555 Zuchongzhi Road, Shanghai, 201203, China
| | - Xinlian Liu
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), 345 Lingling Road, Shanghai, 200032, China
| | - Sheng Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, Hubei, China
| | - Xiying Guo
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, Hubei, China
| | - Chunxi Wang
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), 345 Lingling Road, Shanghai, 200032, China
| | - Hu Zhou
- Department of Analytical Chemistry, Shanghai Institute of Materia Medica, CAS, 555 Zuchongzhi Road, Shanghai, 201203, China
| | - Jiuping Ding
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, Hubei, China
| | - Chunyang Cao
- State Key Laboratory of Bioorganic and Natural Product Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences (CAS), 345 Lingling Road, Shanghai, 200032, China. .,University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing, 100049, China. .,Collaborative Innovation Center of Chemistry for Life Sciences, Chinese Academy of Sciences (CAS), 345 Lingling Road, Shanghai, 200032, China.
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Nishimura-Danjobara Y, Oyama K, Yokoigawa K, Oyama Y. Hyperpolarization by N-(3-oxododecanoyl)-l-homoserine-lactone, a quorum sensing molecule, in rat thymic lymphocytes. Chem Biol Interact 2018; 283:91-96. [PMID: 29427588 DOI: 10.1016/j.cbi.2018.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/22/2018] [Accepted: 02/05/2018] [Indexed: 11/25/2022]
Abstract
To study the adverse effects of N-(3-oxododecanoyl)-l-homoserine-lactone (ODHL), a quorum sensing molecule, on mammalian host cells, its effect on membrane potential was examined in rat thymic lymphocytes using flow cytometric techniques with a voltage-sensitive fluorescent probe. As 3-300 μM ODHL elicited hyperpolarization, it is likely that it increases membrane K+ permeability because hyperpolarization is directly linked to changing K+ gradient across membranes, but not Na+ and Cl- gradients. ODHL did not increase intracellular Ca2+ concentration. ODHL also produced a response in the presence of an intracellular Zn2+ chelator. Thus, it is unlikely that intracellular Ca2+ and Zn2+ are attributed to the response. Quinine, a non-specific K+ channel blocker, greatly reduced hyperpolarization. However, because charybdotoxin, tetraethylammonium chloride, 4-aminopyridine, and glibenclamide did not affect it, it is pharmacologically hypothesized that Ca2+-activated K+ channels, voltage-gated K+ channels, and ATP-sensitive K+ channels are not involved in ODHL-induced hyperpolarization. Although the K+ channels responsible for ODHL-induced hyperpolarization have not been identified, it is suggested that ODHL can elicit hyperpolarization in mammalian host cells, disturbing cellular functions.
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Affiliation(s)
- Yumiko Nishimura-Danjobara
- Department of Food Science, Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Keisuke Oyama
- Department of Food Science, Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Kumio Yokoigawa
- Department of Food Science, Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Yasuo Oyama
- Department of Food Science, Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan.
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38
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Geron M, Hazan A, Priel A. Animal Toxins Providing Insights into TRPV1 Activation Mechanism. Toxins (Basel) 2017; 9:toxins9100326. [PMID: 29035314 PMCID: PMC5666373 DOI: 10.3390/toxins9100326] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/13/2017] [Accepted: 10/13/2017] [Indexed: 02/06/2023] Open
Abstract
Beyond providing evolutionary advantages, venoms offer unique research tools, as they were developed to target functionally important proteins and pathways. As a key pain receptor in the nociceptive pathway, transient receptor potential vanilloid 1 (TRPV1) of the TRP superfamily has been shown to be a target for several toxins, as a way of producing pain to deter predators. Importantly, TRPV1 is involved in thermoregulation, inflammation, and acute nociception. As such, toxins provide tools to understand TRPV1 activation and modulation, a critical step in advancing pain research and the development of novel analgesics. Indeed, the phytotoxin capsaicin, which is the spicy chemical in chili peppers, was invaluable in the original cloning and characterization of TRPV1. The unique properties of each subsequently characterized toxin have continued to advance our understanding of functional, structural, and biophysical characteristics of TRPV1. By building on previous reviews, this work aims to provide a comprehensive summary of the advancements made in TRPV1 research in recent years by employing animal toxins, in particular DkTx, RhTx, BmP01, Echis coloratus toxins, APHCs and HCRG21. We examine each toxin’s functional aspects, behavioral effects, and structural features, all of which have contributed to our current knowledge of TRPV1. We additionally discuss the key features of TRPV1’s outer pore domain, which proves to be the target of the currently discussed toxins.
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Affiliation(s)
- Matan Geron
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
| | - Adina Hazan
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
| | - Avi Priel
- The Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
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39
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Jiménez-Vargas JM, Possani LD, Luna-Ramírez K. Arthropod toxins acting on neuronal potassium channels. Neuropharmacology 2017; 127:139-160. [PMID: 28941737 DOI: 10.1016/j.neuropharm.2017.09.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 01/01/2023]
Abstract
Arthropod venoms are a rich mixture of biologically active compounds exerting different physiological actions across diverse phyla and affecting multiple organ systems including the central nervous system. Venom compounds can inhibit or activate ion channels, receptors and transporters with high specificity and affinity providing essential insights into ion channel function. In this review, we focus on arthropod toxins (scorpions, spiders, bees and centipedes) acting on neuronal potassium channels. A brief description of the K+ channels classification and structure is included and a compendium of neuronal K+ channels and the arthropod toxins that modify them have been listed. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- Juana María Jiménez-Vargas
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - Lourival D Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Colonia Chamilpa, Apartado Postal 510-3, Cuernavaca 62210, Mexico
| | - Karen Luna-Ramírez
- Illawarra Health and Medical Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
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Takeda M, Oyama K, Kamemura N, Kanemaru K, Yuasa K, Yokoigawa K, Oyama Y. Change in plasma membrane potential of rat thymocytes by tert-butylhydroquinone, a food additive: Possible risk on lymphocytes. Food Chem Toxicol 2017; 109:296-301. [PMID: 28899772 DOI: 10.1016/j.fct.2017.09.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 08/25/2017] [Accepted: 09/08/2017] [Indexed: 12/12/2022]
Abstract
Tertiary butylhydroquinone (TBHQ) is a food additive and has various beneficial actions under in vitro and in vivo experimental conditions. Therefore, it is necessary to collect additional data on the toxicity of TBHQ in order to avoid adverse effects during clinical applications. Changes in plasma membrane potential are associated with changes in physiological functions even in non-excitable cells such as lymphocytes. Thus, compounds that affect membrane potential may modify some lymphocytic functions. The effect of TBHQ on plasma membrane potential was examined in rat thymocytes using flow cytometric techniques. Treatment of rat thymocytes with TBHQ caused hyperpolarization and then depolarization. The TBHQ-induced hyperpolarization was due to the activation of Ca2+-dependent K+ channels. TBHQ elevated intracellular Ca2+ levels. The depolarization by TBHQ was caused by a nonspecific increase in membrane ionic permeability. Both the sustained depolarization and elevation of intracellular Ca2+ level by TBHQ are thought to be adverse for thymocytes because such changes disturb membrane and intracellular signaling. The thymus is most active during neonatal and pre-adolescent periods. If TBHQ exerts adverse actions on thymocytes, it may result in an immunotoxic effect in neonates and adolescents.
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Affiliation(s)
- Maki Takeda
- Faculty of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan
| | - Keisuke Oyama
- Osaka University Hospital, Suita, Osaka 565-0871, Japan
| | - Norio Kamemura
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Kaori Kanemaru
- Faculty of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan; Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Keizo Yuasa
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Kumio Yokoigawa
- Faculty of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan; Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Yasuo Oyama
- Faculty of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan; Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan.
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Venom-derived peptides inhibiting Kir channels: Past, present, and future. Neuropharmacology 2017; 127:161-172. [PMID: 28716449 DOI: 10.1016/j.neuropharm.2017.07.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/05/2017] [Accepted: 07/13/2017] [Indexed: 12/17/2022]
Abstract
Inwardly rectifying K+ (Kir) channels play a significant role in vertebrate and invertebrate biology by regulating the movement of K+ ions involved in membrane transport and excitability. Yet unlike other ion channels including their ancestral K+-selective homologs, there are very few venom toxins known to target and inhibit Kir channels with the potency and selectivity found for the Ca2+-activated and voltage-gated K+ channel families. It is unclear whether this is simply due to a lack of discovery, or instead a consequence of the evolutionary processes that drive the development of venom components towards their targets based on a collective efficacy to 1) elicit pain for defensive purposes, 2) promote paralysis for prey capture, or 3) facilitate delivery of venom components into the circulation. The past two decades of venom screening has yielded three venom peptides with inhibitory activity towards mammalian Kir channels, including the discovery of tertiapin, a high-affinity pore blocker from the venom of the European honey bee Apis mellifera. Venomics and structure-based computational approaches represent exciting new frontiers for venom peptide development, where re-engineering peptide 'scaffolds' such as tertiapin may aid in the quest to expand the palette of potent and selective Kir channel blockers for future research and potentially new therapeutics. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Mobli M, Undheim EAB, Rash LD. Modulation of Ion Channels by Cysteine-Rich Peptides: From Sequence to Structure. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 79:199-223. [PMID: 28528669 DOI: 10.1016/bs.apha.2017.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Venom peptides are natural ligands of ion channels and have been used extensively in pharmacological characterization of various ion channels and receptors. In this chapter, we survey all known venom peptide ion-channel modulators. Our survey reveals that the majority of venom peptides characterized to date target voltage-gated sodium or potassium channels. We further find that the majority of these peptides are found in scorpion and spider venoms. We discuss the influence of the pharmacological tools available in biasing discovery and the classical "toxin-to-sequence" approach to venom peptide biodiscovery. The impact of high-throughput sequencing on the existing discovery framework is likely to be significant and we propose here an alternative "sequence-to-toxin" approach to peptide screening, relying more on recently developed high-throughput methods. Methods for production and characterization of disulfide rich toxins in a high-throughput setting are then described, focusing on bacterial protein expression and solution state structural characterization by NMR spectroscopy. Finally, the role of X-ray crystallography and cryo-EM are highlighted by discussing the currently known channel-peptide complexes.
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Affiliation(s)
- Mehdi Mobli
- Centre for Advanced Imaging, St Lucia, QLD, Australia.
| | | | - Lachlan D Rash
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD, Australia
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Windley MJ, Vetter I, Lewis RJ, Nicholson GM. Lethal effects of an insecticidal spider venom peptide involve positive allosteric modulation of insect nicotinic acetylcholine receptors. Neuropharmacology 2017; 127:224-242. [PMID: 28396143 DOI: 10.1016/j.neuropharm.2017.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/28/2017] [Accepted: 04/06/2017] [Indexed: 01/17/2023]
Abstract
κ-Hexatoxins (κ-HXTXs) are a family of excitotoxic insect-selective neurotoxins from Australian funnel-web spiders that are lethal to a wide range of insects, but display no toxicity towards vertebrates. The prototypic κ-HXTX-Hv1c selectively blocks native and expressed cockroach large-conductance calcium-activated potassium (BKCa or KCa1.1) channels, but not their mammalian orthologs. Despite this potent and selective action on insect KCa1.1 channels, we found that the classical KCa1.1 blockers paxilline, charybdotoxin and iberiotoxin, which all block insect KCa1.1 channels, are not lethal in crickets. We therefore used whole-cell patch-clamp analysis of cockroach dorsal unpaired median (DUM) neurons to study the effects of κ-HXTX-Hv1c on sodium-activated (KNa), delayed-rectifier (KDR) and 'A-type' transient (KA) K+ channels. 1 μM κ-HXTX-Hv1c failed to significantly inhibit cockroach KNa and KDR channels, but did cause a 30 ± 7% saturating inhibition of KA channel currents, possibly via a Kv4 (Shal-like) action. However, this modest action at such a high concentration of κ-HXTX-Hv1c would indicate a different lethal target. Accordingly, we assessed the actions of κ-HXTX-Hv1c on neurotransmitter-gated ion channels in cockroach DUM neurons. We found that κ-HXTX-Hv1c failed to produce any major effects on GABAA or glutamate-Cl receptors but dramatically slowed nicotine-evoked ACh receptor (nAChR) current decay and reversed nAChR desensitization. These actions occurred without any alterations to nAChR current amplitude or the nicotine concentration-response curve, and are consistent with a positive allosteric modulation of nAChRs. κ-HXTX-Hv1c therefore represents the first venom peptide that selectively modulates insect nAChRs with a mode of action similar to the excitotoxic insecticide spinosyn A. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- Monique J Windley
- School of Life Sciences, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, University of Queensland, Brisbane St. Lucia, QLD 4072, Australia; School of Pharmacy, University of Queensland, Brisbane St. Lucia, QLD 4072, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, University of Queensland, Brisbane St. Lucia, QLD 4072, Australia
| | - Graham M Nicholson
- School of Life Sciences, University of Technology Sydney, Broadway, NSW 2007, Australia.
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Chavan T, Maduke M, Swartz K. Protein ligands for studying ion channel proteins. J Gen Physiol 2017; 149:407-411. [PMID: 28270405 PMCID: PMC5379924 DOI: 10.1085/jgp.201711776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chavan et al. highlight work showing that a monobody can inhibit a fluoride channel using a mechanism similar to that of a scorpion toxin blocker of potassium channels.
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Affiliation(s)
- Tanmay Chavan
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Merritt Maduke
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Kenton Swartz
- Molecular Physiology and Biophysics Section, John Edward Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
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Wang X, Wang G. Insights into Antimicrobial Peptides from Spiders and Scorpions. Protein Pept Lett 2017; 23:707-21. [PMID: 27165405 DOI: 10.2174/0929866523666160511151320] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 05/03/2016] [Accepted: 05/08/2016] [Indexed: 12/19/2022]
Abstract
The venoms of spiders and scorpions contain a variety of chemical compounds. Antimicrobial peptides (AMPs) from these organisms were first discovered in the 1990s. As of May 2015, there were 42 spider's and 63 scorpion's AMPs in the Antimicrobial Peptide Database (http://aps.unmc.edu/AP). These peptides have demonstrated broad or narrow-spectrum activities against bacteria, fungi, viruses, and parasites. In addition, they can be toxic to cancer cells, insects and erythrocytes. To provide insight into such an activity spectrum, this article discusses the discovery, classification, structure and activity relationships, bioinformatics analysis, and potential applications of spider and scorpion AMPs. Our analysis reveals that, in the case of linear peptides, spiders use both glycine-rich and helical peptide models for defense, whereas scorpions use two distinct helical peptide models with different amino acid compositions to exert the observed antimicrobial activities and hemolytic toxicity. Our structural bioinformatics study improves the knowledge in the field and can be used to design more selective peptides to combat tumors, parasites, and viruses.
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Affiliation(s)
| | - Guangshun Wang
- Department of Pathology and Microbiology, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha, NE 68198-6495, USA.
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Sumino A, Uchihashi T, Oiki S. Oriented Reconstitution of the Full-Length KcsA Potassium Channel in a Lipid Bilayer for AFM Imaging. J Phys Chem Lett 2017; 8:785-793. [PMID: 28139934 DOI: 10.1021/acs.jpclett.6b03058] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Here, we have developed a method of oriented reconstitution of the KcsA potassium channel amenable to high-resolution AFM imaging. The solubilized full-length KcsA channels with histidine-tagged (His-tag) C-terminal ends were attached to a Ni2+-coated mica surface, and then detergent-destabilized liposomes were added to fill the interchannel space. AFM revealed that the membrane-embedded KcsA channels were oriented with their extracellular faces upward, seen as a tetrameric square shape. This orientation was corroborated by the visible binding of a peptide scorpion toxin, agitoxin-2. To observe the cytoplasmic side of the channel, a His-tag was inserted into the extracellular loop, and the oppositely oriented channels provided wholly different images. In either orientation, the channels were individually dispersed at acidic pH, whereas they were self-assembled at neutral pH, indicating that the oriented channels are allowed to diffuse in the membrane. This method is readily applicable to membrane proteins in general for AFM imaging.
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Affiliation(s)
- Ayumi Sumino
- PRESTO, Japan Science and Technology Agency (JST) , 4-1-8 Honcho, Kawaguchi-shi, Saitama 332-0012, Japan
- Department of Molecular Physiology and Biophysics, Faculty of Medical Sciences, University of Fukui , 23-3 Matsuokashimoaizuki, Yoshida-gun, Fukui 910-1193, Japan
| | - Takayuki Uchihashi
- Department of Physics, Kanazawa University , Kakuma-machi, Kanazawa 920-1192, Japan
- Bio-AFM Frontier Research Center , Kanazawa 920-1192, Japan
| | - Shigetoshi Oiki
- Department of Molecular Physiology and Biophysics, Faculty of Medical Sciences, University of Fukui , 23-3 Matsuokashimoaizuki, Yoshida-gun, Fukui 910-1193, Japan
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da Mata ÉCG, Mourão CBF, Rangel M, Schwartz EF. Antiviral activity of animal venom peptides and related compounds. J Venom Anim Toxins Incl Trop Dis 2017; 23:3. [PMID: 28074089 PMCID: PMC5217322 DOI: 10.1186/s40409-016-0089-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/30/2016] [Indexed: 12/11/2022] Open
Abstract
Viruses exhibit rapid mutational capacity to trick and infect host cells, sometimes assisted through virus-coded peptides that counteract host cellular immune defense. Although a large number of compounds have been identified as inhibiting various viral infections and disease progression, it is urgent to achieve the discovery of more effective agents. Furthermore, proportionally to the great variety of diseases caused by viruses, very few viral vaccines are available, and not all are efficient. Thus, new antiviral substances obtained from natural products have been prospected, including those derived from venomous animals. Venoms are complex mixtures of hundreds of molecules, mostly peptides, that present a large array of biological activities and evolved to putatively target the biochemical machinery of different pathogens or host cellular structures. In addition, non-venomous compounds, such as some body fluids of invertebrate organisms, exhibit antiviral activity. This review provides a panorama of peptides described from animal venoms that present antiviral activity, thereby reinforcing them as important tools for the development of new therapeutic drugs.
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Affiliation(s)
- Élida Cleyse Gomes da Mata
- Laboratory of Toxinology, Department of Physiological Sciences, University of Brasília, Brasília, DF 70910-900 Brazil
| | | | - Marisa Rangel
- Laboratory of Toxinology, Department of Physiological Sciences, University of Brasília, Brasília, DF 70910-900 Brazil ; Laboratory of Immunopathology, Butantan Institute, São Paulo, SP 05508-900 Brazil
| | - Elisabeth Ferroni Schwartz
- Laboratory of Toxinology, Department of Physiological Sciences, University of Brasília, Brasília, DF 70910-900 Brazil
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Latorre R, Castillo K, Carrasquel-Ursulaez W, Sepulveda RV, Gonzalez-Nilo F, Gonzalez C, Alvarez O. Molecular Determinants of BK Channel Functional Diversity and Functioning. Physiol Rev 2017; 97:39-87. [DOI: 10.1152/physrev.00001.2016] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Large-conductance Ca2+- and voltage-activated K+ (BK) channels play many physiological roles ranging from the maintenance of smooth muscle tone to hearing and neurosecretion. BK channels are tetramers in which the pore-forming α subunit is coded by a single gene ( Slowpoke, KCNMA1). In this review, we first highlight the physiological importance of this ubiquitous channel, emphasizing the role that BK channels play in different channelopathies. We next discuss the modular nature of BK channel-forming protein, in which the different modules (the voltage sensor and the Ca2+ binding sites) communicate with the pore gates allosterically. In this regard, we review in detail the allosteric models proposed to explain channel activation and how the models are related to channel structure. Considering their extremely large conductance and unique selectivity to K+, we also offer an account of how these two apparently paradoxical characteristics can be understood consistently in unison, and what we have learned about the conduction system and the activation gates using ions, blockers, and toxins. Attention is paid here to the molecular nature of the voltage sensor and the Ca2+ binding sites that are located in a gating ring of known crystal structure and constituted by four COOH termini. Despite the fact that BK channels are coded by a single gene, diversity is obtained by means of alternative splicing and modulatory β and γ subunits. We finish this review by describing how the association of the α subunit with β or with γ subunits can change the BK channel phenotype and pharmacology.
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Affiliation(s)
- Ramon Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Karen Castillo
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Willy Carrasquel-Ursulaez
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Romina V. Sepulveda
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Fernando Gonzalez-Nilo
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Carlos Gonzalez
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Osvaldo Alvarez
- Centro Interdisciplinario de Neurociencia de Valparaíso and Doctorado en Ciencias Mención Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatics and Integrative Biology, Avenida Republica 239, Santiago, Chile and Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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Han T, Ming H, Deng L, Zhu H, Liu Z, Zhang J, Song Y. A novel expression vector for the improved solubility of recombinant scorpion venom in Escherichia coli. Biochem Biophys Res Commun 2017; 482:120-125. [DOI: 10.1016/j.bbrc.2016.09.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 09/11/2016] [Indexed: 12/30/2022]
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Tarr DEK. Establishing a reference array for the CS-αβ superfamily of defensive peptides. BMC Res Notes 2016; 9:490. [PMID: 27863510 PMCID: PMC5116183 DOI: 10.1186/s13104-016-2291-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 11/09/2016] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND "Invertebrate defensins" belong to the cysteine-stabilized alpha-beta (CS-αβ), also known as the scorpion toxin-like, superfamily. Some other peptides belonging to this superfamily of defensive peptides are indistinguishable from "defensins," but have been assigned other names, making it unclear what, if any, criteria must be met to qualify as an "invertebrate defensin." In addition, there are other groups of defensins in invertebrates and vertebrates that are considered to be evolutionarily unrelated to those in the CS-αβ superfamily. This complicates analyses and discussions of this peptide group. This paper investigates the criteria for classifying a peptide as an invertebrate defensin, suggests a reference cysteine array that may be helpful in discussing peptides in this superfamily, and proposes that the superfamily (rather than the name "defensin") is the appropriate context for studying the evolution of invertebrate defensins with the CS-αβ fold. METHODS CS-αβ superfamily sequences were identified from previous literature and BLAST searches of public databases. Sequences were retrieved from databases, and the relevant motifs were identified and used to create a conceptual alignment to a ten-cysteine reference array. Amino acid sequences were aligned in MEGA6 with manual adjustments to ensure accurate alignment of cysteines. Phylogenetic analyses were performed in MEGA6 (maximum likelihood) and MrBayes (Bayesian). RESULTS Across invertebrate taxa, the term "defensin" is not consistently applied based on number of cysteines, cysteine spacing pattern, spectrum of antimicrobial activity, or phylogenetic relationship. The analyses failed to reveal any criteria that unify "invertebrate defensins" and differentiate them from other defensive peptides in the CS-αβ superfamily. Sequences from various groups within the CS-αβ superfamily of defensive peptides can be described by a ten-cysteine reference array that aligns their defining structural motifs. CONCLUSIONS The proposed ten-cysteine reference array can be used in addition to current nomenclature to compare sequences in the CS-αβ superfamily and clarify their features relative to one another. This will facilitate analysis and discussion of "invertebrate defensins" in an appropriate evolutionary context, rather than relying on nomenclature.
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Affiliation(s)
- D Ellen K Tarr
- Department of Microbiology and Immunology, Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ, USA.
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