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Wei Y, Yu Z, Wang L, Li X, Li N, Bai Q, Wang Y, Li R, Meng Y, Xu H, Wang X, Dong Y, Huang Z, Zhang XC, Zhao Y. Structural bases of inhibitory mechanism of Ca V1.2 channel inhibitors. Nat Commun 2024; 15:2772. [PMID: 38555290 PMCID: PMC10981686 DOI: 10.1038/s41467-024-47116-8] [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: 12/05/2022] [Accepted: 03/19/2024] [Indexed: 04/02/2024] Open
Abstract
The voltage-gated calcium channel CaV1.2 is essential for cardiac and vessel smooth muscle contractility and brain function. Accumulating evidence demonstrates that malfunctions of CaV1.2 are involved in brain and heart diseases. Pharmacological inhibition of CaV1.2 is therefore of therapeutic value. Here, we report cryo-EM structures of CaV1.2 in the absence or presence of the antirheumatic drug tetrandrine or antihypertensive drug benidipine. Tetrandrine acts as a pore blocker in a pocket composed of S6II, S6III, and S6IV helices and forms extensive hydrophobic interactions with CaV1.2. Our structure elucidates that benidipine is located in the DIII-DIV fenestration site. Its hydrophobic sidechain, phenylpiperidine, is positioned at the exterior of the pore domain and cradled within a hydrophobic pocket formed by S5DIII, S6DIII, and S6DIV helices, providing additional interactions to exert inhibitory effects on both L-type and T-type voltage gated calcium channels. These findings provide the structural foundation for the rational design and optimization of therapeutic inhibitors of voltage-gated calcium channels.
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Affiliation(s)
- Yiqing Wei
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhuoya Yu
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lili Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Xiaojing Li
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Na Li
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Qinru Bai
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuhang Wang
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Renjie Li
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yufei Meng
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hao Xu
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Xianping Wang
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yanli Dong
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China.
| | - Xuejun Cai Zhang
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Yan Zhao
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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Identification of ultra-rare disruptive variants in voltage-gated calcium channel-encoding genes in Japanese samples of schizophrenia and autism spectrum disorder. Transl Psychiatry 2022; 12:84. [PMID: 35220405 PMCID: PMC8882172 DOI: 10.1038/s41398-022-01851-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/03/2022] [Accepted: 02/09/2022] [Indexed: 12/27/2022] Open
Abstract
Several large-scale whole-exome sequencing studies in patients with schizophrenia (SCZ) and autism spectrum disorder (ASD) have identified rare variants with modest or strong effect size as genetic risk factors. Dysregulation of cellular calcium homeostasis might be involved in SCZ/ASD pathogenesis, and genes encoding L-type voltage-gated calcium channel (VGCC) subunits Cav1.1 (CACNA1S), Cav1.2 (CACNA1C), Cav1.3 (CACNA1D), and T-type VGCC subunit Cav3.3 (CACNA1I) recently were identified as risk loci for psychiatric disorders. We performed a screening study, using the Ion Torrent Personal Genome Machine (PGM), of exon regions of these four candidate genes (CACNA1C, CACNA1D, CACNA1S, CACNA1I) in 370 Japanese patients with SCZ and 192 with ASD. Variant filtering was applied to identify biologically relevant mutations that were not registered in the dbSNP database or that have a minor allele frequency of less than 1% in East-Asian samples from databases; and are potentially disruptive, including nonsense, frameshift, canonical splicing site single nucleotide variants (SNVs), and non-synonymous SNVs predicted as damaging by five different in silico analyses. Each of these filtered mutations were confirmed by Sanger sequencing. If parental samples were available, segregation analysis was employed for measuring the inheritance pattern. Using our filter, we discovered one nonsense SNV (p.C1451* in CACNA1D), one de novo SNV (p.A36V in CACNA1C), one rare short deletion (p.E1675del in CACNA1D), and 14 NSstrict SNVs (non-synonymous SNV predicted as damaging by all of five in silico analyses). Neither p.A36V in CACNA1C nor p.C1451* in CACNA1D were found in 1871 SCZ cases, 380 ASD cases, or 1916 healthy controls in the independent sample set, suggesting that these SNVs might be ultra-rare SNVs in the Japanese population. The neuronal splicing isoform of Cav1.2 with the p.A36V mutation, discovered in the present study, showed reduced Ca2+-dependent inhibition, resulting in excessive Ca2+ entry through the mutant channel. These results suggested that this de novo SNV in CACNA1C might predispose to SCZ by affecting Ca2+ homeostasis. Thus, our analysis successfully identified several ultra-rare and potentially disruptive gene variants, lending partial support to the hypothesis that VGCC-encoding genes may contribute to the risk of SCZ/ASD.
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Yeow SQZ, Loh KWZ, Soong TW. Calcium Channel Splice Variants and Their Effects in Brain and Cardiovascular Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:67-86. [DOI: 10.1007/978-981-16-4254-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Campuzano O, Fernandez-Falgueras A, Lemus X, Sarquella-Brugada G, Cesar S, Coll M, Mates J, Arbelo E, Jordà P, Perez-Serra A, Del Olmo B, Ferrer-Costa C, Iglesias A, Fiol V, Puigmulé M, Lopez L, Pico F, Brugada J, Brugada R. Short QT Syndrome: A Comprehensive Genetic Interpretation and Clinical Translation of Rare Variants. J Clin Med 2019; 8:jcm8071035. [PMID: 31315195 PMCID: PMC6678338 DOI: 10.3390/jcm8071035] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 12/14/2022] Open
Abstract
Short QT syndrome, one of the most lethal entities associated with sudden cardiac death, is a rare genetic disease characterized by short QT intervals detected by electrocardiogram. Several genetic variants are causally linked to the disease, but there has yet to be a comprehensive analysis of variants among patients with short QT syndrome. To fill this gap, we performed an exhaustive study of variants currently catalogued as deleterious in short QT syndrome according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Analysis of the 32 variants described in the literature determined that only nine (28.12%) have a conclusive pathogenic role. All definitively pathogenic variants are located in KCNQ1, KCNH2, or KCNJ2; three genes encoding potassium channels. Other variants located in genes encoding calcium or sodium channels are associated with electrical alterations concomitant with shortened QT intervals but do not guarantee a diagnosis of short QT syndrome. We recommend caution regarding previously reported variants classified as pathogenic. An exhaustive re-analysis is necessary to clarify the role of each variant before routinely translating genetic findings to the clinical setting.
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Affiliation(s)
- Oscar Campuzano
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain.
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain.
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain.
- Biochemistry and Molecular Genetics Department, Hospital Clinic, IDIBAPS, 08036 Barcelona, Spain.
| | | | - Ximena Lemus
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Georgia Sarquella-Brugada
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
| | - Sergi Cesar
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
| | - Monica Coll
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Jesus Mates
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Elena Arbelo
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | - Paloma Jordà
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | | | - Bernat Del Olmo
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Carles Ferrer-Costa
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Anna Iglesias
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Victoria Fiol
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
| | - Marta Puigmulé
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Laura Lopez
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Ferran Pico
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Josep Brugada
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | - Ramon Brugada
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain.
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain.
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain.
- Cardiology Service, Hospital Josep Trueta, University of Girona, 17007 Girona, Spain.
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Bartels P, Yu D, Huang H, Hu Z, Herzig S, Soong TW. Alternative Splicing at N Terminus and Domain I Modulates Ca V1.2 Inactivation and Surface Expression. Biophys J 2019; 114:2095-2106. [PMID: 29742403 DOI: 10.1016/j.bpj.2018.03.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/12/2018] [Accepted: 03/27/2018] [Indexed: 10/17/2022] Open
Abstract
The CaV1.2 L-type calcium channel is a key conduit for Ca2+ influx to initiate excitation-contraction coupling for contraction of the heart and vasoconstriction of the arteries and for altering membrane excitability in neurons. Its α1C pore-forming subunit is known to undergo extensive alternative splicing to produce many CaV1.2 isoforms that differ in their electrophysiological and pharmacological properties. Here, we examined the structure-function relationship of human CaV1.2 with respect to the inclusion or exclusion of mutually exclusive exons of the N-terminus exons 1/1a and IS6 segment exons 8/8a. These exons showed tissue selectivity in their expression patterns: heart variant 1a/8a, one smooth-muscle variant 1/8, and a brain isoform 1/8a. Overall, the 1/8a, when coexpressed with CaVβ2a, displayed a significant and distinct shift in voltage-dependent activation and inactivation and inactivation kinetics as compared to the other three splice variants. Further analysis showed a clear additive effect of the hyperpolarization shift in V1/2inact of CaV1.2 channels containing exon 1 in combination with 8a. However, this additive effect was less distinct for V1/2act. However, the measured effects were β-subunit-dependent when comparing CaVβ2a with CaVβ3 coexpression. Notably, calcium-dependent inactivation mediated by local Ca2+-sensing via the N-lobe of calmodulin was significantly enhanced in exon-1-containing CaV1.2 as compared to exon-1a-containing CaV1.2 channels. At the cellular level, the current densities of the 1/8a or 1/8 variants were significantly larger than the 1a/8a and 1a/8 variants when coexpressed either with CaVβ2a or CaVβ3 subunit. This finding correlated well with a higher channel surface expression for the exon 1-CaV1.2 isoform that we quantified by protein surface-expression levels or by gating currents. Our data also provided a deeper molecular understanding of the altered biophysical properties of alternatively spliced human CaV1.2 channels by directly comparing unitary single-channel events with macroscopic whole-cell currents.
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Affiliation(s)
- Peter Bartels
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Dejie Yu
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Hua Huang
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Zhenyu Hu
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Stefan Herzig
- Department of Pharmacology, University of Cologne, Cologne, Germany
| | - Tuck Wah Soong
- Department of Physiology, National University of Singapore, Singapore, Singapore; NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore; Neurobiology/Ageing Programme, National University of Singapore, Singapore, Singapore; National Neuroscience Institute, Singapore, Singapore.
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Conrad R, Stölting G, Hendriks J, Ruello G, Kortzak D, Jordan N, Gensch T, Hidalgo P. Rapid Turnover of the Cardiac L-Type Ca V1.2 Channel by Endocytic Recycling Regulates Its Cell Surface Availability. iScience 2018; 7:1-15. [PMID: 30267672 PMCID: PMC6135870 DOI: 10.1016/j.isci.2018.08.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/18/2018] [Accepted: 08/10/2018] [Indexed: 02/06/2023] Open
Abstract
Calcium entry through CaV1.2 L-type calcium channels regulates cardiac contractility. Here, we study the impact of exocytic and post-endocytic trafficking on cell surface channel abundance in cardiomyocytes. Single-molecule localization and confocal microscopy reveal an intracellular CaV1.2 pool tightly associated with microtubules from the perinuclear region to the cell periphery, and with actin filaments at the cell cortex. Channels newly inserted into the plasma membrane become internalized with an average time constant of 7.5 min and are sorted out to the Rab11a-recycling compartment. CaV1.2 recycling suffices for maintaining stable L-type current amplitudes over 20 hr independent of de novo channel transport along microtubules. Disruption of the actin cytoskeleton re-routes CaV1.2 from recycling toward lysosomal degradation. We identify endocytic recycling as essential for the homeostatic regulation of voltage-dependent calcium influx into cardiomyocytes. This mechanism provides the basis for a dynamic adjustment of the channel's surface availability and thus, of heart's contraction.
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Affiliation(s)
- Rachel Conrad
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Gabriel Stölting
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Johnny Hendriks
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Giovanna Ruello
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Daniel Kortzak
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Nadine Jordan
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Thomas Gensch
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Patricia Hidalgo
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany; Institute of Biochemistry, Heinrich-Heine University, Düsseldorf, Germany.
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Zhang Q, Chen J, Qin Y, Wang J, Zhou L. Mutations in voltage-gated L-type calcium channel: implications in cardiac arrhythmia. Channels (Austin) 2018; 12:201-218. [PMID: 30027834 PMCID: PMC6104696 DOI: 10.1080/19336950.2018.1499368] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/08/2018] [Accepted: 07/05/2018] [Indexed: 02/06/2023] Open
Abstract
The voltage-gated L-type calcium channel (LTCC) is essential for multiple cellular processes. In the heart, calcium influx through LTCC plays an important role in cardiac electrical excitation. Mutations in LTCC genes, including CACNA1C, CACNA1D, CACNB2 and CACNA2D, will induce the dysfunctions of calcium channels, which result in the abnormal excitations of cardiomyocytes, and finally lead to cardiac arrhythmias. Nevertheless, the newly found mutations in LTCC and their functions are continuously being elucidated. This review summarizes recent findings on the mutations of LTCC, which are associated with long QT syndromes, Timothy syndromes, Brugada syndromes, short QT syndromes, and some other cardiac arrhythmias. Indeed, we describe the gain/loss-of-functions of these mutations in LTCC, which can give an explanation for the phenotypes of cardiac arrhythmias. Moreover, we present several challenges in the field at present, and propose some diagnostic or therapeutic approaches to these mutation-associated cardiac diseases in the future.
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Affiliation(s)
- Qing Zhang
- Department of Cardiology, the Second Affiliated Hospital of Nantong University, Nantong First Hospital, Nantong, Jiangsu, China
- Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Junjie Chen
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yao Qin
- Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Juejin Wang
- Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Lei Zhou
- Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
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Briot J, Tétreault MP, Bourdin B, Parent L. Inherited Ventricular Arrhythmias: The Role of the Multi-Subunit Structure of the L-Type Calcium Channel Complex. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 966:55-64. [PMID: 28315127 DOI: 10.1007/5584_2016_186] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The normal heartbeat is conditioned by transient increases in the intracellular free Ca2+ concentration. Ca2+ influx in cardiomyocytes is regulated by the activity of the heteromeric L-type voltage-activated CaV1.2 channel. A complex network of interactions between the different proteins forming the ion channel supports the kinetics and the activation gating of the Ca2+ influx. Alterations in the biophysical and biochemical properties or in the biogenesis in any of these proteins can lead to serious disturbances in the cardiac rhythm. The multi-subunit nature of the channel complex is better comprehended by examining the high-resolution three-dimensional structure of the closely related CaV1.1 channel. The architectural map identifies precise interaction loci between the different subunits and paves the way for elucidating the mechanistic basis for the regulation of Ca2+ balance in cardiac myocytes under physiological and pathological conditions.
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Affiliation(s)
- Julie Briot
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Institut Cardiologie de Montréal, Université de Montréal, 5000 Bélanger, Montréal, QC, H1T 1C8, Canada
| | - Marie-Philippe Tétreault
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Institut Cardiologie de Montréal, Université de Montréal, 5000 Bélanger, Montréal, QC, H1T 1C8, Canada
| | - Benoîte Bourdin
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Institut Cardiologie de Montréal, Université de Montréal, 5000 Bélanger, Montréal, QC, H1T 1C8, Canada
| | - Lucie Parent
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Institut Cardiologie de Montréal, Université de Montréal, 5000 Bélanger, Montréal, QC, H1T 1C8, Canada.
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Cardiac voltage-gated calcium channel macromolecular complexes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1806-12. [PMID: 26707467 DOI: 10.1016/j.bbamcr.2015.12.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 12/14/2015] [Accepted: 12/16/2015] [Indexed: 11/21/2022]
Abstract
Over the past 20 years, a new field of research, called channelopathies, investigating diseases caused by ion channel dysfunction has emerged. Cardiac ion channels play an essential role in the generation of the cardiac action potential. Investigators have largely determined the physiological roles of different cardiac ion channels, but little is known about the molecular determinants of their regulation. The voltage-gated calcium channel Ca(v)1.2 shapes the plateau phase of the cardiac action potential and allows the influx of calcium leading to cardiomyocyte contraction. Studies suggest that the regulation of Ca(v)1.2 channels is not uniform in working cardiomyocytes. The notion of micro-domains containing Ca(v)1.2 channels and different calcium channel interacting proteins, called macro-molecular complex, has been proposed to explain these observations. The objective of this review is to summarize the currently known information on the Ca(v)1.2 macromolecular complexes in the cardiac cell and discuss their implication in cardiac function and disorder. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Lukacs V, Mathur J, Mao R, Bayrak-Toydemir P, Procter M, Cahalan SM, Kim HJ, Bandell M, Longo N, Day RW, Stevenson DA, Patapoutian A, Krock BL. Impaired PIEZO1 function in patients with a novel autosomal recessive congenital lymphatic dysplasia. Nat Commun 2015; 6:8329. [PMID: 26387913 PMCID: PMC4578306 DOI: 10.1038/ncomms9329] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/11/2015] [Indexed: 12/25/2022] Open
Abstract
Piezo1 ion channels are mediators of mechanotransduction in several cell types including the vascular endothelium, renal tubular cells and erythrocytes. Gain-of-function mutations in PIEZO1 cause an autosomal dominant haemolytic anaemia in humans called dehydrated hereditary stomatocytosis. However, the phenotypic consequence of PIEZO1 loss of function in humans has not previously been documented. Here we discover a novel role of this channel in the lymphatic system. Through whole-exome sequencing, we identify biallelic mutations in PIEZO1 (a splicing variant leading to early truncation and a non-synonymous missense variant) in a pair of siblings affected with persistent lymphoedema caused by congenital lymphatic dysplasia. Analysis of patients' erythrocytes as well as studies in a heterologous system reveal greatly attenuated PIEZO1 function in affected alleles. Our results delineate a novel clinical category of PIEZO1-associated hereditary lymphoedema.
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Affiliation(s)
- Viktor Lukacs
- Howard Hughes Medical Institute, Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Jayanti Mathur
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, USA
| | - Rong Mao
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah 84108, USA.,Department of Pathology, University of Utah, Salt Lake City, Utah 84112, USA
| | - Pinar Bayrak-Toydemir
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah 84108, USA.,Department of Pathology, University of Utah, Salt Lake City, Utah 84112, USA
| | - Melinda Procter
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah 84108, USA
| | - Stuart M Cahalan
- Howard Hughes Medical Institute, Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Helen J Kim
- Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Michael Bandell
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, USA
| | - Nicola Longo
- Department of Pediatrics, Division of Medical Genetics, University of Utah, Salt Lake City, Utah 84112, USA
| | - Ronald W Day
- Department of Pediatrics, Division of Pediatric Cardiology, University of Utah, Salt Lake City, Utah 84112, USA
| | - David A Stevenson
- Department of Pediatrics, Division of Medical Genetics, University of Utah, Salt Lake City, Utah 84112, USA.,Department of Pediatrics, Division of Medical Genetics, Stanford University, Stanford, California 94305, USA
| | - Ardem Patapoutian
- Howard Hughes Medical Institute, Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Bryan L Krock
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah 84108, USA.,Department of Pathology, University of Utah, Salt Lake City, Utah 84112, USA.,Department of Pathology and Laboratory Medicine, Division of Genomic Diagnostics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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11
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Wemhöner K, Friedrich C, Stallmeyer B, Coffey AJ, Grace A, Zumhagen S, Seebohm G, Ortiz-Bonnin B, Rinné S, Sachse FB, Schulze-Bahr E, Decher N. Gain-of-function mutations in the calcium channel CACNA1C (Cav1.2) cause non-syndromic long-QT but not Timothy syndrome. J Mol Cell Cardiol 2015; 80:186-95. [PMID: 25633834 DOI: 10.1016/j.yjmcc.2015.01.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 12/20/2014] [Accepted: 01/05/2015] [Indexed: 11/24/2022]
Abstract
Gain-of-function mutations in CACNA1C, encoding the L-type Ca(2+) channel Cav1.2, cause Timothy syndrome (TS), a multi-systemic disorder with dysmorphic features, long-QT syndrome (LQTS) and autism spectrum disorders. TS patients have heterozygous mutations (G402S and G406R) located in the alternatively spliced exon 8, causing a gain-of-function by reduced voltage-dependence of inactivation. Screening 540 unrelated patients with non-syndromic forms of LQTS, we identified six functional relevant CACNA1C mutations in different regions of the channel. All these mutations caused a gain-of-function combining different mechanisms, including changes in current amplitude, rate of inactivation and voltage-dependence of activation or inactivation, similar as in TS. Computer simulations support the theory that the novel CACNA1C mutations prolong action potential duration. We conclude that genotype-negative LQTS patients should be investigated for mutations in CACNA1C, as a gain-of-function in Cav1.2 is likely to cause LQTS and only specific and rare mutations, i.e. in exon 8, cause the multi-systemic TS.
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Affiliation(s)
- Konstantin Wemhöner
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
| | - Corinna Friedrich
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Birgit Stallmeyer
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Alison J Coffey
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Andrew Grace
- Department of Biochemistry, University of Cambridge, Hopkins Building, Tennis Court Road, Cambridge CB2 1QW, UK; Papworth Hospital, Cambridge CB23 3RE, UK
| | - Sven Zumhagen
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Guiscard Seebohm
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Beatriz Ortiz-Bonnin
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
| | - Frank B Sachse
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 South 2000 East, Salt Lake City, UT 84112, USA; Department of Bioengineering, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Salt Lake City, UT 84112, USA
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany.
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12
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Simms BA, Souza IA, Zamponi GW. Effect of the Brugada syndrome mutation A39V on calmodulin regulation of Cav1.2 channels. Mol Brain 2014; 7:34. [PMID: 24775099 PMCID: PMC4012176 DOI: 10.1186/1756-6606-7-34] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 04/23/2014] [Indexed: 01/22/2023] Open
Abstract
Background The L-type calcium channel Cav1.2 is important for brain and heart function. The ubiquitous calcium sensing protein calmodulin (CaM) regulates calcium dependent gating of Cav1.2 channels by reducing calcium influx, a process known as calcium-dependent inactivation (CDI). Dissecting the calcium-dependence of CaM in this process has benefited greatly from the use of mutant CaM molecules which are unable to bind calcium to their low affinity (N-lobe) and high affinity (C-lobe) binding sites. Unlike CDI, it is unknown whether CaM can modulate the activation gating of Cav1.2 channels. Results We examined a Cav1.2 point mutant in the N-terminus region of the channel (A39V) that has been previously linked to Brugada syndrome. Using mutant CaM constructs in which the N- and/or C-lobe calcium binding sites were ablated, we were able to show that this Brugada syndrome mutation disrupts N-lobe CDI of the channel. In the course of these experiments, we discovered that all mutant CaM molecules were able to alter the kinetics of channel activation even in the absence of calcium for WT-Cav1.2, but not A39V-Cav1.2 channels. Moreover, CaM mutants differentially shifted the voltage-dependence of activation for WT and A39V-Cav1.2 channels to hyperpolarized potentials. Our data therefore suggest that structural changes in CaM that arise directly from site directed mutagenesis of calcium binding domains alter activation gating of Cav1.2 channels independently of their effects on calcium binding, and that the N-terminus of the channel contributes to this CaM dependent process. Conclusions Our data indicate that caution must be exercised when interpreting the effects of CaM mutants on ion channel gating.
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Affiliation(s)
| | | | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Dr, NW, Calgary T2N 4N1, Canada.
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Stockner T, Koschak A. What can naturally occurring mutations tell us about Ca(v)1.x channel function? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:1598-607. [PMID: 23219801 PMCID: PMC3787742 DOI: 10.1016/j.bbamem.2012.11.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 11/16/2012] [Accepted: 11/17/2012] [Indexed: 11/18/2022]
Abstract
Voltage-gated Ca2 + channels allow for Ca2 +-dependent intracellular signaling by directly mediating Ca2 + ion influx, by physical coupling to intracellular Ca2 + release channels or functional coupling to other ion channels such as Ca2 + activated potassium channels. L-type Ca2 + channels that comprise the family of Cav1 channels are expressed in many electrically excitable tissues and are characterized by their unique sensitivity to dihydropyridines. In this issue, we summarize genetic defects in L-type Ca2 + channels and analyze their role in human diseases (Ca2 + channelopathies); e.g. mutations in Cav1.2 α1 cause Timothy and Brugada syndrome, mutations in Cav1.3 α1 are linked to sinoatrial node dysfunction and deafness while mutations in Cav1.4 α1 are associated with X-linked retinal disorders such as an incomplete form of congenital stationary night blindness. Herein, we also put the mutations underlying the channel's dysfunction into the structural context of the pore-forming α1 subunit. This analysis highlights the importance of combining functional data with structural analysis to gain a deeper understanding for the disease pathophysiology as well as for physiological channel function. This article is part of a Special Issue entitled: Calcium channels.
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Affiliation(s)
- Thomas Stockner
- Medical University Vienna, Center for Physiology and Pharmacology, Department of Pharmacology, Währingerstrasse 13A, 1090 Vienna, Austria
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