1
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Liang Q, Chi G, Cirqueira L, Zhi L, Marasco A, Pilati N, Gunthorpe MJ, Alvaro G, Large CH, Sauer DB, Treptow W, Covarrubias M. The binding and mechanism of a positive allosteric modulator of Kv3 channels. Nat Commun 2024; 15:2533. [PMID: 38514618 PMCID: PMC10957983 DOI: 10.1038/s41467-024-46813-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 03/11/2024] [Indexed: 03/23/2024] Open
Abstract
Small-molecule modulators of diverse voltage-gated K+ (Kv) channels may help treat a wide range of neurological disorders. However, developing effective modulators requires understanding of their mechanism of action. We apply an orthogonal approach to elucidate the mechanism of action of an imidazolidinedione derivative (AUT5), a highly selective positive allosteric modulator of Kv3.1 and Kv3.2 channels. AUT5 modulation involves positive cooperativity and preferential stabilization of the open state. The cryo-EM structure of the Kv3.1/AUT5 complex at a resolution of 2.5 Å reveals four equivalent AUT5 binding sites at the extracellular inter-subunit interface between the voltage-sensing and pore domains of the channel's tetrameric assembly. Furthermore, we show that the unique extracellular turret regions of Kv3.1 and Kv3.2 essentially govern the selective positive modulation by AUT5. High-resolution apo and bound structures of Kv3.1 demonstrate how AUT5 binding promotes turret rearrangements and interactions with the voltage-sensing domain to favor the open conformation.
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Affiliation(s)
- Qiansheng Liang
- Department of Neuroscience,, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA
- Jack and Vicki Farber Institute for Neuroscience and the Jefferson Synaptic Biology Center, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Leonardo Cirqueira
- Laboratorio de Biologia Teorica e Computacional, University of Brasilia, Brasilia, Brazil
| | - Lianteng Zhi
- Department of Neuroscience,, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA
- Jack and Vicki Farber Institute for Neuroscience and the Jefferson Synaptic Biology Center, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Agostino Marasco
- Autifony Srl, Istituto di Ricerca Pediatrica Citta' della Speranza, Via Corso Stati Uniti, 4f, 35127, Padua, Italy
| | - Nadia Pilati
- Autifony Srl, Istituto di Ricerca Pediatrica Citta' della Speranza, Via Corso Stati Uniti, 4f, 35127, Padua, Italy
| | - Martin J Gunthorpe
- Autifony Therapeutics, Ltd, Stevenage Bioscience Catalyst, Gunnels Wood Road, Stevenage, SG1 2FX, UK
| | - Giuseppe Alvaro
- Autifony Srl, Istituto di Ricerca Pediatrica Citta' della Speranza, Via Corso Stati Uniti, 4f, 35127, Padua, Italy
| | - Charles H Large
- Autifony Therapeutics, Ltd, Stevenage Bioscience Catalyst, Gunnels Wood Road, Stevenage, SG1 2FX, UK
| | - David B Sauer
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Werner Treptow
- Laboratorio de Biologia Teorica e Computacional, University of Brasilia, Brasilia, Brazil
| | - Manuel Covarrubias
- Department of Neuroscience,, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA.
- Jack and Vicki Farber Institute for Neuroscience and the Jefferson Synaptic Biology Center, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA.
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2
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Feng H, Clatot J, Kaneko K, Flores-Mendez M, Wengert ER, Koutcher C, Hoddeson E, Lopez E, Lee D, Arias L, Liang Q, Zhang X, Somarowthu A, Covarrubias M, Gunthorpe MJ, Large CH, Akizu N, Goldberg EM. Targeted therapy improves cellular dysfunction, ataxia, and seizure susceptibility in a model of a progressive myoclonus epilepsy. Cell Rep Med 2024; 5:101389. [PMID: 38266642 PMCID: PMC10897515 DOI: 10.1016/j.xcrm.2023.101389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 11/09/2023] [Accepted: 12/20/2023] [Indexed: 01/26/2024]
Abstract
The recurrent variant KCNC1-p.Arg320His causes progressive myoclonus epilepsy (EPM) type 7, defined by progressive myoclonus, epilepsy, and ataxia, and is without effective treatment. KCNC1 encodes the voltage-gated potassium channel subunit Kv3.1, specifically expressed in high-frequency-firing neurons. Variant subunits act via loss of function; hence, EPM7 pathogenesis may involve impaired excitability of Kv3.1-expressing neurons, while enhancing Kv3 activity could represent a viable therapeutic strategy. We generate a mouse model, Kcnc1-p.Arg320His/+, which recapitulates the core features of EPM7, including progressive ataxia and seizure susceptibility. Kv3.1-expressing cerebellar granule cells and neocortical parvalbumin-positive GABAergic interneurons exhibit abnormalities consistent with Kv3 channel dysfunction. A Kv3-specific positive modulator (AUT00206) selectively enhances the firing frequency of Kv3.1-expressing neurons and improves motor function and seizure susceptibility in Kcnc1-Arg320His/+ mice. This work identifies a cellular and circuit basis of dysfunction in EPM7 and demonstrates that Kv3 positive modulators such as AUT00206 have therapeutic potential for the treatment of EPM7.
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Affiliation(s)
- Huijie Feng
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jerome Clatot
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; The Epilepsy Neurogenetics Initiative, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Keisuke Kaneko
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Anesthesiology, Nihon University, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Marco Flores-Mendez
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Eric R Wengert
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Carly Koutcher
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Emily Hoddeson
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Emily Lopez
- The University of Pennsylvania School of Arts and Sciences, Philadelphia, PA, USA
| | - Demetrius Lee
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Leroy Arias
- The University of Pennsylvania School of Arts and Sciences, Philadelphia, PA, USA
| | - Qiansheng Liang
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Xiaohong Zhang
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Ala Somarowthu
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Manuel Covarrubias
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Martin J Gunthorpe
- Autifony Therapeutics, Ltd., Stevenage Bioscience Catalyst, Stevenage SG1 2FX, UK
| | - Charles H Large
- Autifony Therapeutics, Ltd., Stevenage Bioscience Catalyst, Stevenage SG1 2FX, UK
| | - Naiara Akizu
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Departments of Pathology & Laboratory Medicine, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ethan M Goldberg
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; The Epilepsy Neurogenetics Initiative, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Neurology, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Neuroscience, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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3
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Khan R, Chaturvedi P, Sahu P, Ludhiadch A, Singh P, Singh G, Munshi A. Role of Potassium Ion Channels in Epilepsy: Focus on Current Therapeutic Strategies. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:67-87. [PMID: 36578258 DOI: 10.2174/1871527322666221227112621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 11/10/2022] [Accepted: 11/12/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Epilepsy is one of the prevalent neurological disorders characterized by disrupted synchronization between inhibitory and excitatory neurons. Disturbed membrane potential due to abnormal regulation of neurotransmitters and ion transport across the neural cell membrane significantly contributes to the pathophysiology of epilepsy. Potassium ion channels (KCN) regulate the resting membrane potential and are involved in neuronal excitability. Genetic alterations in the potassium ion channels (KCN) have been reported to result in the enhancement of the release of neurotransmitters, the excitability of neurons, and abnormal rapid firing rate, which lead to epileptic phenotypes, making these ion channels a potential therapeutic target for epilepsy. The aim of this study is to explore the variations reported in different classes of potassium ion channels (KCN) in epilepsy patients, their functional evaluation, and therapeutic strategies to treat epilepsy targeting KCN. METHODOLOGY A review of all the relevant literature was carried out to compile this article. RESULTS A large number of variations have been reported in different genes encoding various classes of KCN. These genetic alterations in KCN have been shown to be responsible for disrupted firing properties of neurons. Antiepileptic drugs (AEDs) are the main therapeutic strategy to treat epilepsy. Some patients do not respond favorably to the AEDs treatment, resulting in pharmacoresistant epilepsy. CONCLUSION Further to address the challenges faced in treating epilepsy, recent approaches like optogenetics, chemogenetics, and genome editing, such as clustered regularly interspaced short palindromic repeats (CRISPR), are emerging as target-specific therapeutic strategies.
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Affiliation(s)
- Rahul Khan
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Pragya Chaturvedi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Prachi Sahu
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Abhilash Ludhiadch
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Paramdeep Singh
- Department of Radiology, All India Institute of Medical Sciences, Bathinda, Punjab, 151001 India
| | - Gagandeep Singh
- Department of Neurology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Anjana Munshi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
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4
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Gao K, Lin Z, Wen S, Jiang Y. Potassium channels and epilepsy. Acta Neurol Scand 2022; 146:699-707. [PMID: 36225112 DOI: 10.1111/ane.13695] [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: 07/31/2022] [Accepted: 08/16/2022] [Indexed: 01/10/2023]
Abstract
With the development and application of next-generation sequencing technology, the aetiological diagnosis of genetic epilepsy is rapidly becoming easier and less expensive. Additionally, there is a growing body of research into precision therapy based on genetic diagnosis. The numerous genes in the potassium ion channel family constitute the largest family of ion channels: this family is divided into different subtypes. Potassium ion channels play a crucial role in the electrical activity of neurons and are directly involved in the mechanism of epileptic seizures. In China, scientific research on genetic diagnosis and studies of precision therapy for genetic epilepsy are progressing rapidly. Many cases of epilepsy caused by mutation of potassium channel genes have been identified, and several potassium channel gene targets and drug candidates have been discovered. The purpose of this review is to briefly summarize the progress of research on the precise diagnosis and treatment of potassium ion channel-related genetic epilepsy, especially the research conducted in China. Here in, we review several large cohort studies on the genetic diagnosis of epilepsy in China in recent years, summarized the proportion of potassium channel genes. We focus on the progress of precison therapy on some hot epilepsy related potassium channel genes: KCNA1, KCNA2, KCNB1, KCNC1, KCND2, KCNQ2, KCNQ3, KCNMA1, and KCNT1.
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Affiliation(s)
- Kai Gao
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
| | - Zehong Lin
- Department of Neurology, Affiliated Children's Hospital of Capital Institute of Pediatrics, Beijing, China
| | - Sijia Wen
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
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5
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Chi G, Liang Q, Sridhar A, Cowgill JB, Sader K, Radjainia M, Qian P, Castro-Hartmann P, Venkaya S, Singh NK, McKinley G, Fernandez-Cid A, Mukhopadhyay SMM, Burgess-Brown NA, Delemotte L, Covarrubias M, Dürr KL. Cryo-EM structure of the human Kv3.1 channel reveals gating control by the cytoplasmic T1 domain. Nat Commun 2022; 13:4087. [PMID: 35840580 PMCID: PMC9287412 DOI: 10.1038/s41467-022-29594-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 03/24/2022] [Indexed: 11/26/2022] Open
Abstract
Kv3 channels have distinctive gating kinetics tailored for rapid repolarization in fast-spiking neurons. Malfunction of this process due to genetic variants in the KCNC1 gene causes severe epileptic disorders, yet the structural determinants for the unusual gating properties remain elusive. Here, we present cryo-electron microscopy structures of the human Kv3.1a channel, revealing a unique arrangement of the cytoplasmic tetramerization domain T1 which facilitates interactions with C-terminal axonal targeting motif and key components of the gating machinery. Additional interactions between S1/S2 linker and turret domain strengthen the interface between voltage sensor and pore domain. Supported by molecular dynamics simulations, electrophysiological and mutational analyses, we identify several residues in the S4/S5 linker which influence the gating kinetics and an electrostatic interaction between acidic residues in α6 of T1 and R449 in the pore-flanking S6T helices. These findings provide insights into gating control and disease mechanisms and may guide strategies for the design of pharmaceutical drugs targeting Kv3 channels.
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Affiliation(s)
- Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Qiansheng Liang
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, 19107, UK
| | - Akshay Sridhar
- Department of Applied Physics, Science for Life Laboratory, KTH, Solna, Sweden
| | - John B Cowgill
- Department of Applied Physics, Science for Life Laboratory, KTH, Solna, Sweden
| | - Kasim Sader
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Mazdak Radjainia
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Pu Qian
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Pablo Castro-Hartmann
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Shayla Venkaya
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exscientia Ltd., The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK
| | - Nanki Kaur Singh
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Gavin McKinley
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Alejandra Fernandez-Cid
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exact Sciences Ltd., The Sherard Building, Edmund Halley Road, The Oxford Science Park, Oxford, OX4 4DQ, UK
| | - Shubhashish M M Mukhopadhyay
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exscientia Ltd., The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK
| | - Nicola A Burgess-Brown
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exact Sciences Ltd., The Sherard Building, Edmund Halley Road, The Oxford Science Park, Oxford, OX4 4DQ, UK
| | - Lucie Delemotte
- Department of Applied Physics, Science for Life Laboratory, KTH, Solna, Sweden
| | - Manuel Covarrubias
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, 19107, UK
| | - Katharina L Dürr
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK.
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK.
- OMass Therapeutics, Ltd., The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK.
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6
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Carpenter JC, Männikkö R, Heffner C, Heneine J, Sampedro‐Castañeda M, Lignani G, Schorge S. Progressive myoclonus epilepsy KCNC1 variant causes a developmental dendritopathy. Epilepsia 2021; 62:1256-1267. [PMID: 33735526 PMCID: PMC8436768 DOI: 10.1111/epi.16867] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/17/2021] [Accepted: 02/17/2021] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Mutations in KCNC1 can cause severe neurological dysfunction, including intellectual disability, epilepsy, and ataxia. The Arg320His variant, which occurs in the voltage-sensing domain of the channel, causes a highly penetrant and specific form of progressive myoclonus epilepsy with severe ataxia, designated myoclonus epilepsy and ataxia due to potassium channel mutation (MEAK). KCNC1 encodes the voltage-gated potassium channel KV 3.1, a channel that is important for enabling high-frequency firing in interneurons, raising the possibility that MEAK is associated with reduced interneuronal function. METHODS To determine how this variant triggers MEAK, we expressed KV 3.1bR320H in cortical interneurons in vitro and investigated the effects on neuronal function and morphology. We also performed electrophysiological recordings of oocytes expressing KV 3.1b to determine whether the mutation introduces gating pore currents. RESULTS Expression of the KV 3.1bR320H variant profoundly reduced excitability of mature cortical interneurons, and cells expressing these channels were unable to support high-frequency firing. The mutant channel also had an unexpected effect on morphology, severely impairing neurite development and interneuron viability, an effect that could not be rescued by blocking KV 3 channels. Oocyte recordings confirmed that in the adult KV 3.1b isoform, R320H confers a dominant negative loss-of-function effect by slowing channel activation, but does not introduce potentially toxic gating pore currents. SIGNIFICANCE Overall, our data suggest that, in addition to the regulation of high-frequency firing, KV 3.1 channels play a hitherto unrecognized role in neuronal development. MEAK may be described as a developmental dendritopathy.
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Affiliation(s)
- Jenna C. Carpenter
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Roope Männikkö
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Catherine Heffner
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Jana Heneine
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Marisol Sampedro‐Castañeda
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Gabriele Lignani
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Stephanie Schorge
- Department of PharmacologyUniversity College London School of PharmacyLondonUK
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7
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Allen NM, Weckhuysen S, Gorman K, King MD, Lerche H. Genetic potassium channel-associated epilepsies: Clinical review of the K v family. Eur J Paediatr Neurol 2020; 24:105-116. [PMID: 31932120 DOI: 10.1016/j.ejpn.2019.12.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 12/22/2022]
Abstract
Next-generation sequencing has enhanced discovery of many disease-associated genes in previously unexplained epilepsies, mainly in developmental and epileptic encephalopathies and familial epilepsies. We now classify these disorders according to the underlying molecular pathways, which encompass a diverse array of cellular and sub-cellular compartments/signalling processes including voltage-gated ion-channel defects. With the aim to develop and increase the use of precision medicine therapies, understanding the pathogenic mechanisms and consequences of disease-causing variants has gained major relevance in clinical care. The super-family of voltage-gated potassium channels is the largest and most diverse family among the ion channels, encompassing approximately 80 genes. Key potassium channelopathies include those affecting the KV, KCa and Kir families, a significant proportion of which have been implicated in neurological disease. As for other ion channel disorders, different pathogenic variants within any individual voltage-gated potassium channel gene tend to affect channel protein function differently, causing heterogeneous clinical phenotypes. The focus of this review is to summarise recent clinical developments regarding the key voltage-gated potassium (KV) family-related epilepsies, which now encompasses approximately 12 established disease-associated genes, from the KCNA-, KCNB-, KCNC-, KCND-, KCNV-, KCNQ- and KCNH-subfamilies.
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Affiliation(s)
- Nicholas M Allen
- Department of Paediatrics, National University of Ireland, Galway, Ireland; Department of Paediatrics (Neurology), Galway University Hospital, Ireland; Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland.
| | - Sarah Weckhuysen
- Neurogenetics Group, Center for Molecular Neurology, VIB-University of Antwerp, Antwerp, Belgium; Department of Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Kathleen Gorman
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin 1, Ireland; University College Dublin School of Medicine and Medical Science, University College, Dublin, Ireland
| | - Mary D King
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin 1, Ireland; University College Dublin School of Medicine and Medical Science, University College, Dublin, Ireland
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research, University of Tubingen, Germany
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8
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Park J, Koko M, Hedrich UBS, Hermann A, Cremer K, Haberlandt E, Grimmel M, Alhaddad B, Beck‐Woedl S, Harrer M, Karall D, Kingelhoefer L, Tzschach A, Matthies LC, Strom TM, Ringelstein EB, Sturm M, Engels H, Wolff M, Lerche H, Haack TB. KCNC1-related disorders: new de novo variants expand the phenotypic spectrum. Ann Clin Transl Neurol 2019; 6:1319-1326. [PMID: 31353862 PMCID: PMC6649617 DOI: 10.1002/acn3.50799] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 05/11/2019] [Indexed: 12/30/2022] Open
Abstract
A recurrent de novo missense variant in KCNC1, encoding a voltage-gated potassium channel expressed in inhibitory neurons, causes progressive myoclonus epilepsy and ataxia, and a nonsense variant is associated with intellectual disability. We identified three new de novo missense variants in KCNC1 in five unrelated individuals causing different phenotypes featuring either isolated nonprogressive myoclonus (p.Cys208Tyr), intellectual disability (p.Thr399Met), or epilepsy with myoclonic, absence and generalized tonic-clonic seizures, ataxia, and developmental delay (p.Ala421Val, three patients). Functional analyses demonstrated no measurable currents for all identified variants and dominant-negative effects for p.Thr399Met and p.Ala421Val predicting neuronal disinhibition as the underlying disease mechanism.
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Affiliation(s)
- Joohyun Park
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Mahmoud Koko
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Ulrike B. S. Hedrich
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Andreas Hermann
- Translational Neurodegeneration Section “Albrecht‐Kossel”, Department of Neurology and Center for Transdisciplinary Neurosciences Rostock (CTNR)University Medical Center Rostock, University of Rostock18147RostockGermany
- German Center for Neurodegenerative Diseases (DZNE) Rostock/Greifswald18147RostockGermany
| | - Kirsten Cremer
- Institute of Human GeneticsUniversity of Bonn, School of Medicine and University Hospital BonnBonnGermany
| | - Edda Haberlandt
- Clinic for PediatricsKrankenhaus Stadt DornbirnDornbirnAustria
| | - Mona Grimmel
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
| | - Bader Alhaddad
- Institute of Human GeneticsTechnische Universität MünchenMunichGermany
- Institute of Human GeneticsHelmholtz Zentrum MünchenNeuherbergGermany
| | - Stefanie Beck‐Woedl
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
| | - Merle Harrer
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Daniela Karall
- Clinic for Pediatrics, Division of Inherited Metabolic DisordersMedical University of InnsbruckInnsbruckAustria
| | - Lisa Kingelhoefer
- Department of NeurologyTechnische Universität Dresden and German Center for Neurodegenerative Diseases, Research Side DresdenDresdenGermany
| | - Andreas Tzschach
- Institute of Clinical GeneticsTechnische Universität DresdenDresdenGermany
| | - Lars C. Matthies
- Institute of Human GeneticsUniversity of Bonn, School of Medicine and University Hospital BonnBonnGermany
| | - Tim M. Strom
- Institute of Human GeneticsTechnische Universität MünchenMunichGermany
- Institute of Human GeneticsHelmholtz Zentrum MünchenNeuherbergGermany
| | - Erich Bernd Ringelstein
- Department of NeurologyUniversity Hospital of MuensterMuensterGermany
- German Neuroscience CenterDubaiUnited Arab Emirates
| | - Marc Sturm
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
| | - Hartmut Engels
- Institute of Human GeneticsUniversity of Bonn, School of Medicine and University Hospital BonnBonnGermany
| | - Markus Wolff
- Department of NeuropediatricsUniversity of TübingenTübingenGermany
| | - Holger Lerche
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Tobias B. Haack
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
- Institute of Human GeneticsTechnische Universität MünchenMunichGermany
- Centre for Rare DiseasesUniversity of TübingenTübingenGermany
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