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Marabelli C, Santiago DJ, Priori SG. The Structural-Functional Crosstalk of the Calsequestrin System: Insights and Pathological Implications. Biomolecules 2023; 13:1693. [PMID: 38136565 PMCID: PMC10741413 DOI: 10.3390/biom13121693] [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: 10/30/2023] [Revised: 11/14/2023] [Accepted: 11/21/2023] [Indexed: 12/24/2023] Open
Abstract
Calsequestrin (CASQ) is a key intra-sarcoplasmic reticulum Ca2+-handling protein that plays a pivotal role in the contraction of cardiac and skeletal muscles. Its Ca2+-dependent polymerization dynamics shape the translation of electric excitation signals to the Ca2+-induced contraction of the actin-myosin architecture. Mutations in CASQ are linked to life-threatening pathological conditions, including tubular aggregate myopathy, malignant hyperthermia, and Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). The variability in the penetrance of these phenotypes and the lack of a clear understanding of the disease mechanisms associated with CASQ mutations pose a major challenge to the development of effective therapeutic strategies. In vitro studies have mainly focused on the polymerization and Ca2+-buffering properties of CASQ but have provided little insight into the complex interplay of structural and functional changes that underlie disease. In this review, the biochemical and structural natures of CASQ are explored in-depth, while emphasizing their direct and indirect consequences for muscle Ca2+ physiology. We propose a novel functional classification of CASQ pathological missense mutations based on the structural stability of the monomer, dimer, or linear polymer conformation. We also highlight emerging similarities between polymeric CASQ and polyelectrolyte systems, emphasizing the potential for the use of this paradigm to guide further research.
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Affiliation(s)
- Chiara Marabelli
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy;
- Laboratory of Molecular Cardiology, IRCCS ICS Maugeri, 27100 Pavia, Italy
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain;
| | - Demetrio J. Santiago
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain;
| | - Silvia G. Priori
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy;
- Laboratory of Molecular Cardiology, IRCCS ICS Maugeri, 27100 Pavia, Italy
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain;
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2
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The function and regulation of calsequestrin-2: implications in calcium-mediated arrhythmias. Biophys Rev 2022; 14:329-352. [PMID: 35340602 PMCID: PMC8921388 DOI: 10.1007/s12551-021-00914-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/14/2021] [Indexed: 01/09/2023] Open
Abstract
Cardiac arrhythmias are life-threatening events in which the heart develops an irregular rhythm. Mishandling of Ca2+ within the myocytes of the heart has been widely demonstrated to be an underlying mechanism of arrhythmogenesis. This includes altered function of the ryanodine receptor (RyR2)-the primary Ca2+ release channel located to the sarcoplasmic reticulum (SR). The spontaneous leak of SR Ca2+ via RyR2 is a well-established contributor in the development of arrhythmic contractions. This leak is associated with increased channel activity in response to changes in SR Ca2+ load. RyR2 activity can be regulated through several avenues, including interactions with numerous accessory proteins. One such protein is calsequestrin-2 (CSQ2), which is the primary Ca2+-buffering protein within the SR. The capacity of CSQ2 to buffer Ca2+ is tightly associated with the ability of the protein to polymerise in response to changing Ca2+ levels. CSQ2 can itself be regulated through phosphorylation and glycosylation modifications, which impact protein polymerisation and trafficking. Changes in CSQ2 modifications are implicated in cardiac pathologies, while mutations in CSQ2 have been identified in arrhythmic patients. Here, we review the role of CSQ2 in arrhythmogenesis including evidence for the indirect and direct regulation of RyR2 by CSQ2, and the consequences of a loss of functional CSQ2 in Ca2+ homeostasis and Ca2+-mediated arrhythmias. Supplementary Information The online version contains supplementary material available at 10.1007/s12551-021-00914-6.
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Wang Q, Paskevicius T, Filbert A, Qin W, Kim HJ, Chen XZ, Tang J, Dacks JB, Agellon LB, Michalak M. Phylogenetic and biochemical analysis of calsequestrin structure and association of its variants with cardiac disorders. Sci Rep 2020; 10:18115. [PMID: 33093545 PMCID: PMC7582152 DOI: 10.1038/s41598-020-75097-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/08/2020] [Indexed: 12/16/2022] Open
Abstract
Calsequestrin is among the most abundant proteins in muscle sarcoplasmic reticulum and displays a high capacity but a low affinity for Ca2+ binding. In mammals, calsequestrin is encoded by two genes, CASQ1 and CASQ2, which are expressed almost exclusively in skeletal and cardiac muscles, respectively. Phylogenetic analysis indicates that calsequestrin is an ancient gene in metazoans, and that the duplication of the ancestral calsequestrin gene took place after the emergence of the lancelet. CASQ2 gene variants associated with catecholaminergic polymorphic ventricular tachycardia (CPVT) in humans are positively correlated with a high degree of evolutionary conservation across all calsequestrin homologues. The mutations are distributed in diverse locations of the calsequestrin protein and impart functional diversity but remarkably manifest in a similar phenotype in humans.
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Affiliation(s)
- Qian Wang
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Tautvydas Paskevicius
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Alexander Filbert
- Division of Infectious Disease, Department of Medicine, University of Alberta, Edmonton, AB, T6G 2G3, Canada
| | - Wenying Qin
- Institute of Biomedical and Pharmaceutical Sciences, Key Laboratory of Fermentation Engineering, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, Hubei, China
| | - Hyeong Jin Kim
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Xing-Zhen Chen
- Institute of Biomedical and Pharmaceutical Sciences, Key Laboratory of Fermentation Engineering, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, Hubei, China.,Department of Physiology, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Jingfeng Tang
- Institute of Biomedical and Pharmaceutical Sciences, Key Laboratory of Fermentation Engineering, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, Hubei, China
| | - Joel B Dacks
- Division of Infectious Disease, Department of Medicine, University of Alberta, Edmonton, AB, T6G 2G3, Canada.
| | - Luis B Agellon
- School of Dietetics and Human Nutrition, McGill University, Ste. Anne de Bellevue, Quebec, H9X 3V9, Canada.
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada. .,Institute of Biomedical and Pharmaceutical Sciences, Key Laboratory of Fermentation Engineering, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, Hubei, China.
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4
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The structure of a calsequestrin filament reveals mechanisms of familial arrhythmia. Nat Struct Mol Biol 2020; 27:1142-1151. [PMID: 33046906 PMCID: PMC7718342 DOI: 10.1038/s41594-020-0510-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 08/19/2020] [Indexed: 02/04/2023]
Abstract
Mutations in the calcium-binding protein calsequestrin cause the highly lethal familial arrhythmia catecholaminergic polymorphic ventricular tachycardia (CPVT). In vivo, calsequestrin multimerizes into filaments, but an atomic-resolution structure of a calsequestrin filament is lacking. We report a crystal structure of a human cardiac calsequestrin filament with supporting mutational analysis and in vitro filamentation assays. We identify and characterize a novel disease-associated calsequestrin mutation, S173I, that is located at the filament-forming interface, and further show that a previously reported dominant disease mutation, K180R, maps to the same surface. Both mutations disrupt filamentation, suggesting that disease pathology is due to defects in multimer formation. An ytterbium-derivatized structure pinpoints multiple credible calcium sites at filament-forming interfaces, explaining the atomic basis of calsequestrin filamentation in the presence of calcium. Our study thus provides a unifying molecular mechanism by which dominant-acting calsequestrin mutations provoke lethal arrhythmias.
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5
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Ng K, Titus EW, Lieve KV, Roston TM, Mazzanti A, Deiter FH, Denjoy I, Ingles J, Till J, Robyns T, Connors SP, Steinberg C, Abrams DJ, Pang B, Scheinman MM, Bos JM, Duffett SA, van der Werf C, Maltret A, Green MS, Rutberg J, Balaji S, Cadrin-Tourigny J, Orland KM, Knight LM, Brateng C, Wu J, Tang AS, Skanes AC, Manlucu J, Healey JS, January CT, Krahn AD, Collins KK, Maginot KR, Fischbach P, Etheridge SP, Eckhardt LL, Hamilton RM, Ackerman MJ, Noguer FRI, Semsarian C, Jura N, Leenhardt A, Gollob MH, Priori SG, Sanatani S, Wilde AAM, Deo RC, Roberts JD. An International Multicenter Evaluation of Inheritance Patterns, Arrhythmic Risks, and Underlying Mechanisms of CASQ2-Catecholaminergic Polymorphic Ventricular Tachycardia. Circulation 2020; 142:932-947. [PMID: 32693635 PMCID: PMC7484339 DOI: 10.1161/circulationaha.120.045723] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Genetic variants in calsequestrin-2 (CASQ2) cause an autosomal recessive form of catecholaminergic polymorphic ventricular tachycardia (CPVT), although isolated reports have identified arrhythmic phenotypes among heterozygotes. Improved insight into the inheritance patterns, arrhythmic risks, and molecular mechanisms of CASQ2-CPVT was sought through an international multicenter collaboration. METHODS Genotype-phenotype segregation in CASQ2-CPVT families was assessed, and the impact of genotype on arrhythmic risk was evaluated using Cox regression models. Putative dominant CASQ2 missense variants and the established recessive CASQ2-p.R33Q variant were evaluated using oligomerization assays and their locations mapped to a recent CASQ2 filament structure. RESULTS A total of 112 individuals, including 36 CPVT probands (24 homozygotes/compound heterozygotes and 12 heterozygotes) and 76 family members possessing at least 1 presumed pathogenic CASQ2 variant, were identified. Among CASQ2 homozygotes and compound heterozygotes, clinical penetrance was 97.1% and 26 of 34 (76.5%) individuals had experienced a potentially fatal arrhythmic event with a median age of onset of 7 years (95% CI, 6-11). Fifty-one of 66 CASQ2 heterozygous family members had undergone clinical evaluation, and 17 of 51 (33.3%) met diagnostic criteria for CPVT. Relative to CASQ2 heterozygotes, CASQ2 homozygote/compound heterozygote genotype status in probands was associated with a 3.2-fold (95% CI, 1.3-8.0; P=0.013) increased hazard of a composite of cardiac syncope, aborted cardiac arrest, and sudden cardiac death, but a 38.8-fold (95% CI, 5.6-269.1; P<0.001) increased hazard in genotype-positive family members. In vitro turbidity assays revealed that p.R33Q and all 6 candidate dominant CASQ2 missense variants evaluated exhibited filamentation defects, but only p.R33Q convincingly failed to dimerize. Structural analysis revealed that 3 of these 6 putative dominant negative missense variants localized to an electronegative pocket considered critical for back-to-back binding of dimers. CONCLUSIONS This international multicenter study of CASQ2-CPVT redefines its heritability and confirms that pathogenic heterozygous CASQ2 variants may manifest with a CPVT phenotype, indicating a need to clinically screen these individuals. A dominant mode of inheritance appears intrinsic to certain missense variants because of their location and function within the CASQ2 filament structure.
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Affiliation(s)
- Kevin Ng
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
- Cairns Hospital, Queensland, Australia
| | - Erron W. Titus
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, USA
| | - Krystien V. Lieve
- Amsterdam University Medical Centre, University of Amsterdam, Heart Centre, Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, the Netherlands
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart
| | - Thomas M. Roston
- Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrea Mazzanti
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico and Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Frederick H. Deiter
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, USA
| | - Isabelle Denjoy
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart
- Service de Cardiologie et CNMR Maladies Cardiacques Héréditaires Rares, Hôpital Bichat, Paris, France
| | - Jodie Ingles
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney, Australia
| | - Jan Till
- Department of Cardiology, Royal Brompton Hospital, London, United Kingdom
| | - Tomas Robyns
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart
- Department of Cardiovascular Disease, University Hospitals Leuven, Leuven, Belgium
| | - Sean P. Connors
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Memorial University, St. John’s, Newfoundland and Labrador, Canada
| | | | - Dominic J. Abrams
- Inherited Cardiac Arrhythmia Program, Boston Children’s Hospital, Harvard Medical School, Massachusetts, USA
| | - Benjamin Pang
- Arrhythmia Service, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Melvin M. Scheinman
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, University of California San Francisco, San Francisco, California, USA
| | - J. Martijn Bos
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), and Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, Minnesota, USA
| | - Stephen A. Duffett
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Memorial University, St. John’s, Newfoundland and Labrador, Canada
| | - Christian van der Werf
- Amsterdam University Medical Centre, University of Amsterdam, Heart Centre, Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, the Netherlands
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart
| | - Alice Maltret
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart
- Service de Cardiologie et CNMR Maladies Cardiacques Héréditaires Rares, Hôpital Bichat, Paris, France
| | - Martin S. Green
- Arrhythmia Service, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Julie Rutberg
- Arrhythmia Service, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Seshadri Balaji
- Department of Pediatrics, Division of Cardiology, Oregon Health & Science University, Portland, Oregon, USA
| | - Julia Cadrin-Tourigny
- Cardiovascular Genetics Center, Montreal Heart Institute, Université de Montréal, Montréal, Canada
| | - Kate M. Orland
- University of Wisconsin-Madison Inherited Arrhythmia Clinic, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Linda M. Knight
- Children’s Healthcare of Atlanta, Sibley Heart Center Cardiology, Atlanta, Georgia, USA
| | - Caitlin Brateng
- Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Jeremy Wu
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
| | - Anthony S. Tang
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
| | - Allan C. Skanes
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
| | - Jaimie Manlucu
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
| | - Jeff S. Healey
- Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Craig T. January
- University of Wisconsin-Madison Inherited Arrhythmia Clinic, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Andrew D. Krahn
- Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kathryn K. Collins
- Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Kathleen R. Maginot
- Department of Pediatrics, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, USA
| | - Peter Fischbach
- Children’s Healthcare of Atlanta, Sibley Heart Center Cardiology, Atlanta, Georgia, USA
| | - Susan P. Etheridge
- Department of Pediatrics, University of Utah, and Primary Children’s Hospital, Salt Lake City, Utah, USA
| | - Lee L. Eckhardt
- University of Wisconsin-Madison Inherited Arrhythmia Clinic, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Robert M. Hamilton
- The Labatt Family Heart Centre (Department of Pediatrics) and Translational Medicine, The Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada
| | - Michael J. Ackerman
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), and Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, Minnesota, USA
| | | | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney, Australia
| | - Natalia Jura
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, USA
| | - Antoine Leenhardt
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart
- Service de Cardiologie et CNMR Maladies Cardiacques Héréditaires Rares, Hôpital Bichat, Paris, France
| | - Michael H. Gollob
- Department of Physiology and Department of Medicine, Toronto General Hospital, University of Toronto, Ontario, Canada
| | - Silvia G. Priori
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico and Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Shubhayan Sanatani
- Department of Pediatrics, Children’s Heart Centre, BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Arthur A. M. Wilde
- Amsterdam University Medical Centre, University of Amsterdam, Heart Centre, Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, the Netherlands
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart
| | - Rahul C. Deo
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, USA
- Department of Medicine, University of California San Francisco, San Francisco, California, USA
- One Brave Idea and Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Harvard University, Boston, Massachusetts, USA
| | - Jason D. Roberts
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
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6
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Wang Q, Michalak M. Calsequestrin. Structure, function, and evolution. Cell Calcium 2020; 90:102242. [PMID: 32574906 DOI: 10.1016/j.ceca.2020.102242] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/05/2020] [Accepted: 06/06/2020] [Indexed: 12/25/2022]
Abstract
Calsequestrin is the major Ca2+ binding protein in the sarcoplasmic reticulum (SR), serves as the main Ca2+ storage and buffering protein and is an important regulator of Ca2+ release channels in both skeletal and cardiac muscle. It is anchored at the junctional SR membrane through interactions with membrane proteins and undergoes reversible polymerization with increasing Ca2+ concentration. Calsequestrin provides high local Ca2+ at the junctional SR and communicates changes in luminal Ca2+ concentration to Ca2+ release channels, thus it is an essential component of excitation-contraction coupling. Recent studies reveal new insights on calsequestrin trafficking, Ca2+ binding, protein evolution, protein-protein interactions, stress responses and the molecular basis of related human muscle disease, including catecholaminergic polymorphic ventricular tachycardia (CPVT). Here we provide a comprehensive overview of calsequestrin, with recent advances in structure, diverse functions, phylogenetic analysis, and its role in muscle physiology, stress responses and human pathology.
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Affiliation(s)
- Qian Wang
- Department of Biochemistry, University of Alberta, Edmonton, AB, T6H 2S7, Canada
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, AB, T6H 2S7, Canada.
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7
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Rossi D, Gamberucci A, Pierantozzi E, Amato C, Migliore L, Sorrentino V. Calsequestrin, a key protein in striated muscle health and disease. J Muscle Res Cell Motil 2020; 42:267-279. [PMID: 32488451 DOI: 10.1007/s10974-020-09583-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 05/22/2020] [Accepted: 05/26/2020] [Indexed: 10/24/2022]
Abstract
Calsequestrin (CASQ) is the most abundant Ca2+ binding protein localized in the sarcoplasmic reticulum (SR) of skeletal and cardiac muscle. The genome of vertebrates contains two genes, CASQ1 and CASQ2. CASQ1 and CASQ2 have a high level of homology, but show specific patterns of expression. Fast-twitch skeletal muscle fibers express only CASQ1, both CASQ1 and CASQ2 are present in slow-twitch skeletal muscle fibers, while CASQ2 is the only protein present in cardiomyocytes. Depending on the intraluminal SR Ca2+ levels, CASQ monomers assemble to form large polymers, which increase their Ca2+ binding ability. CASQ interacts with triadin and junctin, two additional SR proteins which contribute to localize CASQ to the junctional region of the SR (j-SR) and also modulate CASQ ability to polymerize into large macromolecular complexes. In addition to its ability to bind Ca2+ in the SR, CASQ appears also to be able to contribute to regulation of Ca2+ homeostasis in muscle cells. Both CASQ1 and CASQ2 are able to either activate and inhibit the ryanodine receptors (RyRs) calcium release channels, likely through their interactions with junctin and triadin. Additional evidence indicates that CASQ1 contributes to regulate the mechanism of store operated calcium entry in skeletal muscle via a direct interaction with the Stromal Interaction Molecule 1 (STIM1). Mutations in CASQ2 and CASQ1 have been identified, respectively, in patients with catecholamine-induced polymorphic ventricular tachycardia and in patients with some forms of myopathy. This review will highlight recent developments in understanding CASQ1 and CASQ2 in health and diseases.
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Affiliation(s)
- Daniela Rossi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Via A. Moro, 2, 53100, Siena, Italy.
| | - Alessandra Gamberucci
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Via A. Moro, 2, 53100, Siena, Italy
| | - Enrico Pierantozzi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Via A. Moro, 2, 53100, Siena, Italy
| | - Caterina Amato
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Via A. Moro, 2, 53100, Siena, Italy
| | - Loredana Migliore
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Via A. Moro, 2, 53100, Siena, Italy
| | - Vincenzo Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Via A. Moro, 2, 53100, Siena, Italy
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8
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Kistamás K, Veress R, Horváth B, Bányász T, Nánási PP, Eisner DA. Calcium Handling Defects and Cardiac Arrhythmia Syndromes. Front Pharmacol 2020; 11:72. [PMID: 32161540 PMCID: PMC7052815 DOI: 10.3389/fphar.2020.00072] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/24/2020] [Indexed: 12/13/2022] Open
Abstract
Calcium ions (Ca2+) play a major role in the cardiac excitation-contraction coupling. Intracellular Ca2+ concentration increases during systole and falls in diastole thereby determining cardiac contraction and relaxation. Normal cardiac function also requires perfect organization of the ion currents at the cellular level to drive action potentials and to maintain action potential propagation and electrical homogeneity at the tissue level. Any imbalance in Ca2+ homeostasis of a cardiac myocyte can lead to electrical disturbances. This review aims to discuss cardiac physiology and pathophysiology from the elementary membrane processes that can cause the electrical instability of the ventricular myocytes through intracellular Ca2+ handling maladies to inherited and acquired arrhythmias. Finally, the paper will discuss the current therapeutic approaches targeting cardiac arrhythmias.
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Affiliation(s)
- Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - Roland Veress
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Department of Dental Physiology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - David A Eisner
- Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
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9
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Chakravarty H, Bal C, Yadav M, Jena N, Bal NC, Sharon A. First Insight on Small Molecules as Cardiac Calsequestrin Stabilizers. ACS OMEGA 2019; 4:11508-11514. [PMID: 31460256 PMCID: PMC6682146 DOI: 10.1021/acsomega.9b01113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 06/19/2019] [Indexed: 06/10/2023]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is caused by mutations of cardiac calsequestrin (CASQ2) that impair its characteristic ability of Ca2+-induced polymerization-depolymerization. However, stabilizing the CASQ2 polymer by pharmacological agents to treat CPVT has not been reported so far. Here, we tested whether small molecules can stabilize CASQ2 polymers. We synthesized 24 glycinate/alaninate/acetate α-pyranone analogs and conducted the CASQ2 depolymerization assay. Most of the molecules of this class of compounds inhibited the depolymerization of the protein upon Ca2+ chelation by ethylene glycol tetraacetic acid. Structure-activity relationship studies revealed that the compounds with the 4-fluoro-phenyl group at the C-6 position of the pyranone ring and open-chain primary amine at C-4 are the most active of the class. This is the first report of an α-pyranone class of compounds with the ability to stabilize CASQ2 polymers and opens up the possibility to target Ca2+-release disorders via modulation of CASQ2 polymerization.
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Affiliation(s)
| | - Chandralata Bal
- Department
of Chemistry, Birla Institute of Technology,
Mesra, Ranchi 835215, India
| | - Monika Yadav
- Department
of Chemistry, Birla Institute of Technology,
Mesra, Ranchi 835215, India
| | - Nivedita Jena
- KIIT Technology Business Incubator and KIIT School of Biotechnology, KIIT University, Bhubaneswar 751021 India
| | - Naresh C. Bal
- KIIT Technology Business Incubator and KIIT School of Biotechnology, KIIT University, Bhubaneswar 751021 India
| | - Ashoke Sharon
- Department
of Chemistry, Birla Institute of Technology,
Mesra, Ranchi 835215, India
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10
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Josephs K, Patel K, Janson CM, Montagna C, McDonald TV. Compound heterozygous CASQ2 mutations and long-term course of catecholaminergic polymorphic ventricular tachycardia. Mol Genet Genomic Med 2017; 5:788-794. [PMID: 29178653 PMCID: PMC5702571 DOI: 10.1002/mgg3.323] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/07/2017] [Accepted: 07/10/2017] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal inherited cardiac disorder characterized by episodic ventricular tachycardia during adrenergic stimulation. It is associated with significant morbidity and mortality. Knowledge of the underlying genetic cause, pathogenesis, and the natural history of the disease remains incomplete. Approximately 50% of CPVT cases are caused by dominant mutations in the cardiac ryanodine receptor (RYR2) gene, <5% of cases are accounted for by recessive mutations in cardiac calsequestrin (CASQ2) or Triadin (TRDN). METHODS We report a family with two CASQ2 gene mutations. A research-based next-generation sequencing (NGS) initiative was used in a patient with a severe CPVT phenotype and her clinically unaffected son. Reverse transcription polymerase chain reaction (RT-PCR) from platelet RNA was used to assess the consequences of predicted splice variants. RESULTS NGS revealed that the proband carried a novel c.199C>T (p.Gln67*) mutation and a previously reported splice site mutation c.532+1G>A in CASQ2. Her son is a heterozygous carrier of the c.199C>T (p.Gln67*) mutation alone and the proband was compound heterozygous at CASQ2. RNA analysis demonstrated that the splice site mutation results in the retention of intron 3 with no full-length CASQ2 mRNA. CONCLUSION This study describes a novel CPVT genotype and further characterizes the effect of a previously reported CASQ2 splice site mutation. The long-term follow-up of 23 years since first symptom provides additional insight into the natural history of CASQ2-associated CPVT.
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Affiliation(s)
- Katherine Josephs
- Department of GeneticsAlbert Einstein College of MedicineBronxNew York
| | - Kunjan Patel
- Department of GeneticsAlbert Einstein College of MedicineBronxNew York
| | - Christopher M. Janson
- Department of Pediatrics (Cardiology)Albert Einstein College of Medicine & Montefiore Medical CenterBronxNew York
| | - Cristina Montagna
- Department of GeneticsAlbert Einstein College of MedicineBronxNew York
| | - Thomas V. McDonald
- Department of Medicine (Cardiology)Albert Einstein College of Medicine & Montefiore Medical CenterBronxNew York
- Department of Molecular PharmacologyAlbert Einstein College of MedicineBronxNew York
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11
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Gergs U, Fahrion CM, Bock P, Fischer M, Wache H, Hauptmann S, Schmitz W, Neumann J. Evidence for a functional role of calsequestrin 2 in mouse atrium. Acta Physiol (Oxf) 2017; 219:669-682. [PMID: 27484853 DOI: 10.1111/apha.12766] [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: 02/01/2016] [Revised: 02/23/2016] [Accepted: 07/30/2016] [Indexed: 12/01/2022]
Abstract
AIM Several genetically modified mice models were studied so far to investigate the role of cardiac calsequestrin (CSQ2) for the contractile function of the ventricle and for the occurrence of ventricular tachycardia. Using a CSQ2 knockout mouse, we wanted to study also the atrial function of CSQ2. METHODS The influence of CSQ2 on atrial function and, for comparison, ventricular function was studied in isolated cardiac preparations and by echocardiography as well as electrocardiography in mice with deletion of CSQ2. RESULTS Using deletion of exon 1, we have successfully generated a constitutive knockout mouse of the calsequestrin 2 gene (CSQ2-/- ). CSQ2 protein was absent in the heart (atrium, ventricle), but also in oesophagus and skeletal muscle of homozygous knockout mice. In 6-month-old CSQ2-/- mice, relative left atrial weight was increased, whereas relative heart weight was unchanged. The staircase phenomena in paced left atrial preparations on force of contraction and the post-rest potentiation were different between wild type and CSQ2-/- indicative for a decreased sarcoplasmic Ca2+ load and supporting an important role of CSQ2 also in the atrium. The incidence of arrhythmias was increased in CSQ2-/- . In 2-year-old CSQ2-/- mice, cardiac hypertrophy and heart failure were noted possibly as a result of chronically increased cytosolic Ca2+ levels. CONCLUSION These data suggest a functional role of CSQ2 not only in the ventricle but also in the atrium of mammalian hearts. Loss of CSQ2 function can cause not only arrhythmias, but also cardiac hypertrophy and heart failure.
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Affiliation(s)
- U. Gergs
- Institut für Pharmakologie und Toxikologie; Medizinische Fakultät; Martin-Luther-Universität Halle-Wittenberg; Halle/Saale Germany
| | - C. M. Fahrion
- Institut für Pharmakologie und Toxikologie; Medizinische Fakultät; Martin-Luther-Universität Halle-Wittenberg; Halle/Saale Germany
| | - P. Bock
- Institut für Pharmakologie und Toxikologie; Medizinische Fakultät; Martin-Luther-Universität Halle-Wittenberg; Halle/Saale Germany
| | - M. Fischer
- Institut für Pharmakologie und Toxikologie; Medizinische Fakultät; Martin-Luther-Universität Halle-Wittenberg; Halle/Saale Germany
| | - H. Wache
- Institut für Pharmakologie und Toxikologie; Medizinische Fakultät; Martin-Luther-Universität Halle-Wittenberg; Halle/Saale Germany
| | - S. Hauptmann
- Institut für Pathologie am Krankenhaus Düren gGmbH; Düren Germany
| | - W. Schmitz
- Institut für Pharmakologie und Toxikologie; Universitätsklinikum Münster; Münster Germany
| | - J. Neumann
- Institut für Pharmakologie und Toxikologie; Medizinische Fakultät; Martin-Luther-Universität Halle-Wittenberg; Halle/Saale Germany
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12
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Bal NC, Jena N, Chakravarty H, Kumar A, Chi M, Balaraju T, Rawale SV, Rawale JS, Sharon A, Periasamy M. The C-terminal calcium-sensitive disordered motifs regulate isoform-specific polymerization characteristics of calsequestrin. Biopolymers 2016; 103:15-22. [PMID: 25091206 DOI: 10.1002/bip.22534] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 07/31/2014] [Accepted: 08/01/2014] [Indexed: 12/14/2022]
Abstract
Calsequestrin (CASQ) exists as two distinct isoforms CASQ1 and CASQ2 in all vertebrates. Although the isoforms exhibit unique functional characteristic, the structural basis for the same is yet to be fully defined. Interestingly, the C-terminal region of the two isoforms exhibit significant differences both in length and amino acid composition; forming Dn-motif and DEXn-motif in CASQ1 and CASQ2, respectively. Here, we investigated if the unique C-terminal motifs possess Ca(2+)-sensitivity and affect protein function. Sequence analysis shows that both the Dn- and DEXn-motifs are intrinsically disordered regions (IDRs) of the protein, a feature that is conserved from fish to man. Using purified synthetic peptides, we show that these motifs undergo distinctive Ca(2+)-mediated folding suggesting that these disordered motifs are Ca(2+)-sensitivity. We generated chimeric proteins by swapping the C-terminal portions between CASQ1 and CASQ2. Our studies show that the C-terminal portions do not play significant role in protein folding. An interesting finding of the current study is that the switching of the C-terminal portion completely reverses the polymerization kinetics. Collectively, these data suggest that these Ca(2+)-sensitivity IDRs located at the back-to-back dimer interface influence isoform-specific Ca(2+)-dependent polymerization properties of CASQ.
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Affiliation(s)
- Naresh C Bal
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, 43210
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13
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Valle G, Boncompagni S, Sacchetto R, Protasi F, Volpe P. Post-natal heart adaptation in a knock-in mouse model of calsequestrin 2-linked recessive catecholaminergic polymorphic ventricular tachycardia. Exp Cell Res 2013; 321:178-89. [PMID: 24370574 DOI: 10.1016/j.yexcr.2013.12.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 12/05/2013] [Accepted: 12/11/2013] [Indexed: 01/13/2023]
Abstract
Cardiac calsequestrin (CASQ2) contributes to intracellular Ca(2+) homeostasis by virtue of its low-affinity/high-capacity Ca(2+) binding properties, maintains sarcoplasmic reticulum (SR) architecture and regulates excitation-contraction coupling, especially or exclusively upon β-adrenergic stimulation. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disease associated with cardiac arrest in children or young adults. Recessive CPVT variants are due to mutations in the CASQ2 gene. Molecular and ultra-structural properties were studied in hearts of CASQ2(R33Q/R33Q) and of CASQ2(-/-) mice from post-natal day 2 to week 8. The drastic reduction of CASQ2-R33Q is an early developmental event and is accompanied by down-regulation of triadin and junctin, and morphological changes of jSR and of SR-transverse-tubule junctions. Although endoplasmic reticulum stress is activated, no signs of either apoptosis or autophagy are detected. The other model of recessive CPVT, the CASQ2(-/-) mouse, does not display the same adaptive pattern. Expression of CASQ2-R33Q influences molecular and ultra-structural heart development; post-natal, adaptive changes appear capable of ensuring until adulthood a new pathophysiological equilibrium.
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Affiliation(s)
- Giorgia Valle
- Dipartimento di Scienze Biomediche dell'Università di Padova, Istituto di Neuroscienze del CNR, Istituto Interuniversitario di Miologia, viale G. Colombo 3, 35121 Padova, Italy
| | - Simona Boncompagni
- Dipartimento di Neuroscienze e Imaging dell'Università Gabriele D'Annunzio, Centro Scienze dell'Invecchiamento, Chieti, Italy
| | - Roberta Sacchetto
- Dipartimento di Biomedicina Comparata ed Alimentazione dell'Università di Padova, Padova, Italy
| | - Feliciano Protasi
- Dipartimento di Neuroscienze e Imaging dell'Università Gabriele D'Annunzio, Centro Scienze dell'Invecchiamento, Chieti, Italy
| | - Pompeo Volpe
- Dipartimento di Scienze Biomediche dell'Università di Padova, Istituto di Neuroscienze del CNR, Istituto Interuniversitario di Miologia, viale G. Colombo 3, 35121 Padova, Italy.
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14
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Gaburjakova M, Bal NC, Gaburjakova J, Periasamy M. Functional interaction between calsequestrin and ryanodine receptor in the heart. Cell Mol Life Sci 2013; 70:2935-45. [PMID: 23109100 PMCID: PMC11113811 DOI: 10.1007/s00018-012-1199-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 10/02/2012] [Accepted: 10/15/2012] [Indexed: 11/25/2022]
Abstract
Evidence obtained in the last two decades indicates that calsequestrin (CSQ2), as the major Ca(2+)-binding protein in the sarcoplasmic reticulum of cardiac myocytes, communicates changes in the luminal Ca(2+) concentration to the cardiac ryanodine receptor (RYR2) channel. This review summarizes the major aspects in the interaction between CSQ2 and the RYR2 channel. The single channel properties of RYR2 channels, discussed here in the context of structural changes in CSQ2 after Ca(2+) binding, are particularly important. We focus on five important questions concerning: (1) the method for reliable detection of CSQ2 on the reconstituted RYR2 channel complex; (2) the power of the procedure to strip CSQ2 from the RYR2 channel complex; (3) structural changes in CSQ2 upon binding of Ca(2+) which cause CSQ2 dissociation; (4) the potential role of CSQ2-independent regulation of the RYR2 activity by luminal Ca(2+); and (5) the vizualization of CSQ2 dissociation from the RYR2 channel complex on the single channel level. We discuss the potential sources of the conflicting experimental results which may aid detailed understanding of the CSQ2 regulatory role. Although we mainly focus on the cardiac isoform of the proteins, some aspects of more extensive work carried out on the skeletal isoform are also discussed.
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Affiliation(s)
- Marta Gaburjakova
- Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlarska 5, Bratislava, Slovak Republic.
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Stefl S, Nishi H, Petukh M, Panchenko AR, Alexov E. Molecular mechanisms of disease-causing missense mutations. J Mol Biol 2013; 425:3919-36. [PMID: 23871686 DOI: 10.1016/j.jmb.2013.07.014] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 07/04/2013] [Accepted: 07/10/2013] [Indexed: 12/23/2022]
Abstract
Genetic variations resulting in a change of amino acid sequence can have a dramatic effect on stability, hydrogen bond network, conformational dynamics, activity and many other physiologically important properties of proteins. The substitutions of only one residue in a protein sequence, so-called missense mutations, can be related to many pathological conditions and may influence susceptibility to disease and drug treatment. The plausible effects of missense mutations range from affecting the macromolecular stability to perturbing macromolecular interactions and cellular localization. Here we review the individual cases and genome-wide studies that illustrate the association between missense mutations and diseases. In addition, we emphasize that the molecular mechanisms of effects of mutations should be revealed in order to understand the disease origin. Finally, we report the current state-of-the-art methodologies that predict the effects of mutations on protein stability, the hydrogen bond network, pH dependence, conformational dynamics and protein function.
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Affiliation(s)
- Shannon Stefl
- Computational Biophysics and Bioinformatics, Department of Physics, Clemson University, Clemson, SC 29634, USA
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16
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Kumar A, Chakravarty H, Bal NC, Balaraju T, Jena N, Misra G, Bal C, Pieroni E, Periasamy M, Sharon A. Identification of calcium binding sites on calsequestrin 1 and their implications for polymerization. MOLECULAR BIOSYSTEMS 2013; 9:1949-57. [PMID: 23629537 PMCID: PMC3719380 DOI: 10.1039/c3mb25588c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biophysical studies have shown that each molecule of calsequestrin 1 (CASQ1) can bind about 70-80 Ca(2+) ions. However, the nature of Ca(2+)-binding sites has not yet been fully characterized. In this study, we employed in silico approaches to identify the Ca(2+) binding sites and to understand the molecular basis of CASQ1-Ca(2+) recognition. We built the protein model by extracting the atomic coordinates for the back-to-back dimeric unit from the recently solved hexameric CASQ1 structure (PDB id: ) and adding the missing C-terminal residues (aa350-364). Using this model we performed extensive 30 ns molecular dynamics simulations over a wide range of Ca(2+) concentrations ([Ca(2+)]). Our results show that the Ca(2+)-binding sites on CASQ1 differ both in affinity and geometry. The high affinity Ca(2+)-binding sites share a similar geometry and interestingly, the majority of them were found to be induced by increased [Ca(2+)]. We also found that the system shows maximal Ca(2+)-binding to the CAS (consecutive aspartate stretch at the C-terminus) before the rest of the CASQ1 surface becomes saturated. Simulated data show that the CASQ1 back-to-back stacking is progressively stabilized by the emergence of an increasing number of hydrophobic interactions with increasing [Ca(2+)]. Further, this study shows that the CAS domain assumes a compact structure with an increase in Ca(2+) binding, which suggests that the CAS domain might function as a Ca(2+)-sensor that may be a novel structural motif to sense metal. We propose the term "Dn-motif" for the CAS domain.
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Affiliation(s)
- Amit Kumar
- CRS4, Bioengineering group, Science and Technology Park Polaris, Piscina Manna, 09010 Pula (CA). Italy
| | - Harapriya Chakravarty
- Department of Applied Chemistry, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India
| | - Naresh C. Bal
- Department of Physiology and Cell Biology, The Ohio State University, College of Medicine, Columbus, OH 43210, United States
| | - Tuniki Balaraju
- Department of Applied Chemistry, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India
| | - Nivedita Jena
- College of Pharmacy, The Ohio State University, Columbus, OH 43210, United States
| | - Gauri Misra
- Institute of Biotechnology, Amity University, Noida, India
| | - Chandralata Bal
- Department of Applied Chemistry, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India
| | - Enrico Pieroni
- CRS4, Bioengineering group, Science and Technology Park Polaris, Piscina Manna, 09010 Pula (CA). Italy
| | - Muthu Periasamy
- Department of Physiology and Cell Biology, The Ohio State University, College of Medicine, Columbus, OH 43210, United States
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA
| | - Ashoke Sharon
- Department of Applied Chemistry, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India
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Whittington AC, Nienow TE, Whittington CL, Fort TJ, Grove TJ. Functional and structural characterization of a eurytolerant calsequestrin from the intertidal teleost Fundulus heteroclitus. PLoS One 2012; 7:e50801. [PMID: 23226387 PMCID: PMC3511267 DOI: 10.1371/journal.pone.0050801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 10/25/2012] [Indexed: 02/07/2023] Open
Abstract
Calsequestrins (CSQ) are high capacity, medium affinity, calcium-binding proteins present in the sarcoplasmic reticulum (SR) of cardiac and skeletal muscles. CSQ sequesters Ca2+ during muscle relaxation and increases the Ca2+-storage capacity of the SR. Mammalian CSQ has been well studied as a model of human disease, but little is known about the environmental adaptation of CSQ isoforms from poikilothermic organisms. The mummichog, Fundulus heteroclitus, is an intertidal fish that experiences significant daily and seasonal environmental fluctuations and is an interesting study system for investigations of adaptation at the protein level. We determined the full-length coding sequence of a CSQ isoform from skeletal muscle of F. heteroclitus (FCSQ) and characterized the function and structure of this CSQ. The dissociation constant (Kd) of FCSQ is relatively insensitive to changes in temperature and pH, thus indicating that FCSQ is a eurytolerant protein. We identified and characterized a highly conserved salt bridge network in FCSQ that stabilizes the formation of front-to-front dimers, a process critical to CSQ function. The functional profile of FCSQ correlates with the natural history of F. heteroclitus suggesting that the eurytolerant function of FCSQ may be adaptive.
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Affiliation(s)
- A. Carl Whittington
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, United States of America
| | - Tatyana E. Nienow
- Department of Biology, Valdosta State University, Valdosta, Georgia, United States of America
| | - Christi L. Whittington
- Department of Chemistry, University of South Florida, Tampa, Florida, United States of America
| | - Timothy J. Fort
- Department of Biology, Valdosta State University, Valdosta, Georgia, United States of America
| | - Theresa J. Grove
- Department of Biology, Valdosta State University, Valdosta, Georgia, United States of America
- * E-mail:
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Calsequestrin mutations and catecholaminergic polymorphic ventricular tachycardia. Pediatr Cardiol 2012; 33:959-67. [PMID: 22421959 PMCID: PMC3393815 DOI: 10.1007/s00246-012-0256-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 02/16/2012] [Indexed: 10/28/2022]
Abstract
Cardiac calsequestrin (Casq2) is the major Ca2+ binding protein in the sarcoplasmic reticulum, which is the principle Ca2+ storage organelle of cardiac muscle. During the last decade, experimental studies have provided new concepts on the role of Casq2 in the regulation of cardiac muscle Ca2+ handling. Furthermore, mutations in the gene encoding for cardiac calsequestrin, CASQ2, cause a rare but severe form of catecholaminergic polymorphic ventricular tachycardia (CPVT). Here, we review the physiology of Casq2 in cardiac Ca2+ handling and discuss pathophysiological mechanisms that lead to CPVT caused by CASQ2 mutations. We also describe the clinical aspects of CPVT and provide an update of its contemporary clinical management.
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19
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Venetucci L, Denegri M, Napolitano C, Priori SG. Inherited calcium channelopathies in the pathophysiology of arrhythmias. Nat Rev Cardiol 2012; 9:561-75. [DOI: 10.1038/nrcardio.2012.93] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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20
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Abstract
Calsequestrin is the most abundant Ca-binding protein of the specialized endoplasmic reticulum found in muscle, the sarcoplasmic reticulum (SR). Calsequestrin binds Ca with high capacity and low affinity and importantly contributes to the mobilization of Ca during each contraction both in skeletal and cardiac muscle. Surprisingly, mutations in the gene encoding the cardiac isoform of calsequestrin (Casq2) have been associated with an inherited form of ventricular arrhythmia triggered by emotional or physical stress termed catecholaminergic polymorphic ventricular tachycardia (CPVT). Despite normal cardiac contractility and normal resting ECG, CPVT patients present with a high risk of sudden death at a young age. Here, we review recent new insights regarding the role of calsequestrin in genetic and acquired arrhythmia disorders. Mouse models of CPVT have shed light on the pathophysiological mechanism underlying CPVT. Casq2 is not only a Ca-storing protein as initially hypothesized, but it has a far more complex function in Ca handling and regulating SR Ca release channels. The functional importance of Casq2 interactions with other SR proteins and the importance of alterations in Casq2 trafficking are also being investigated. Reports of altered Casq2 trafficking in animal models of acquired heart diseases such as heart failure suggest that Casq2 may contribute to arrhythmia risk beyond genetic forms of Casq2 dysfunction.
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Affiliation(s)
- Michela Faggioni
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0575, USA
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21
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Abstract
CASQ (calsequestrin) is a Ca2+-buffering protein localized in the muscle SR (sarcoplasmic reticulum); however, it is unknown whether Ca2+ binding to CASQ2 is due to its location inside the SR rich in Ca2+ or due to its preference for Ca2+ over other ions. Therefore a major aim of the present study was to determine how CASQ2 selects Ca2+ over other metal ions by studying monomer folding and subsequent aggregation upon exposure to alkali (monovalent), alkaline earth (divalent) and transition (polyvalent) metals. We additionally investigated how CPVT (catecholaminergic polymorphic ventricular tachycardia) mutations affect CASQ2 structure and its molecular behaviour when exposed to different metal ions. Our results show that alkali and alkaline earth metals can initiate similar molecular compaction (folding), but only Ca2+ can promote CASQ2 to aggregate, suggesting that CASQ2 has a preferential binding to Ca2+ over all other metals. We additionally found that transition metals (having higher co-ordinated bonding ability than Ca2+) can also initiate folding and promote aggregation of CASQ2. These studies led us to suggest that folding and formation of higher-order structures depends on cationic properties such as co-ordinate bonding ability and ionic radius. Among the CPVT mutants studied, the L167H mutation disrupts the Ca2+-dependent folding and, when folding is achieved by Mn2+, L167H can undergo aggregation in a Ca2+-dependent manner. Interestingly, domain III mutants (D307H and P308L) lost their selectivity to Ca2+ and could be aggregated in the presence of Mg2+. In conclusion, these studies suggest that CPVT mutations modify CASQ2 behaviour, including folding, aggregation/polymerization and selectivity towards Ca2+.
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22
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Mechanism underlying catecholaminergic polymorphic ventricular tachycardia and approaches to therapy. J Electrocardiol 2011; 44:650-5. [PMID: 21872879 DOI: 10.1016/j.jelectrocard.2011.07.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Indexed: 02/03/2023]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by VT induced by adrenergic stress in the absence of structural heart disease and high incidence of sudden cardiac death. The diagnosis is made based on reproducible ventricular tachyarrhythmias including bidirectional VT and polymorphic VT during exercise testings. Two causative genes of CPVT have been identified: RYR2, encoding the cardiac ryanodine receptor (RyR2) Ca(2+) release channel, and CASQ2, encoding cardiac calsequestrin. A mutation in RYR2 or CASQ2 is identified in approximately 60% of patients with CPVT. Mutations in these two genes destabilize the RyR2 Ca(2+) release channel complex in sarcoplasmic reticulum and result in spontaneous Ca(2+) release through RyR2 channels leading to delayed after depolarization, triggered activity, and bidirectional/polymorphic VT. Implantable cardioverter defibrillators (ICDs) are recommended for prevention of sudden death in patients with CPVT.1. A.E. Epstein, J.P. DiMarco, K.A. Ellenbogen, et al., ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons. Circulation. 2008;117:e350 However, painful shocks can trigger further adrenergic stress and arrhythmias, and deaths have occurred despite appropriate ICD shocks. Treatment with β-adrenergic blockers reduces arrhythmia burden and mortality, but is not completely effective. The beneficial effects of Ca(2+) channel blocker verapamil in combination with β-blocker have been reported, but the role of verapamil has not been well assessed. Because Ca(2+) leakage through ryanodine channel is a common mechanism of CPVT, ryanodine channel block may have a therapeutic effect. We discovered that flecainide directly inhibits RyR2 channels and prevent CPVT. Left cardiac sympathetic denervation may be an effective alternative treatment in combination with ICD, especially for patients whose arrhythmias are not controlled by drug therapies.
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Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disease occurring in patients with a structurally normal heart: the disease is characterized by life-threatening arrhythmias elicited by stress and emotion. In 2001, the ryanodine receptor was identified as the gene that is linked to CPVT; shortly thereafter, cardiac calsequestrin was implicated in the recessive form of the same disease. It became clear that abnormalities in intracellular Ca(2+) regulation could profoundly disrupt the electrophysiological properties of the heart. In this article, we discuss the molecular basis of the disease and the pathophysiological mechanisms that are impacting clinical diagnosis and management of affected individuals. As of today, the interaction between basic scientists and clinicians to understand CPVT and identify new therapeutic strategies is one of the most compelling examples of the importance of translational research in cardiology.
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Affiliation(s)
- Silvia G Priori
- Molecular Cardiology Laboratories, IRCCS Fondazione Salvatore Maugeri, Via Maugeri 10/10A, Pavia, Italy.
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MacLennan DH, Zvaritch E. Mechanistic models for muscle diseases and disorders originating in the sarcoplasmic reticulum. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:948-64. [DOI: 10.1016/j.bbamcr.2010.11.009] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 11/11/2010] [Accepted: 11/18/2010] [Indexed: 11/29/2022]
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Knollmann BC. A "rough" journey to the sarcoplasmic reticulum--implications of altered calsequestrin trafficking for cardiac arrhythmia. J Mol Cell Cardiol 2010; 49:554-5. [PMID: 20603128 DOI: 10.1016/j.yjmcc.2010.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 06/23/2010] [Indexed: 11/25/2022]
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