1
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Weston TGR, Rees M, Gautel M, Fraternali F. Walking with giants: The challenges of variant impact assessment in the giant sarcomeric protein titin. WIREs Mech Dis 2024; 16:e1638. [PMID: 38155593 DOI: 10.1002/wsbm.1638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/30/2023]
Abstract
Titin, the so-called "third filament" of the sarcomere, represents a difficult challenge for the determination of damaging genetic variants. A single titin molecule extends across half the length of a sarcomere in striated muscle, fulfilling a variety of vital structural and signaling roles, and has been linked to an equally varied range of myopathies, resulting in a significant burden on individuals and healthcare systems alike. While the consequences of truncating variants of titin are well-documented, the ramifications of the missense variants prevalent in the general population are less so. We here present a compendium of titin missense variants-those that result in a single amino-acid substitution in coding regions-reported to be pathogenic and discuss these in light of the nature of titin and the variant position within the sarcomere and their domain, the structural, pathological, and biophysical characteristics that define them, and the methods used for characterization. Finally, we discuss the current knowledge and integration of the multiple fields that have contributed to our understanding of titin-related pathology and offer suggestions as to how these concurrent methodologies may aid the further development in our understanding of titin and hopefully extend to other, less well-studied giant proteins. This article is categorized under: Cardiovascular Diseases > Genetics/Genomics/Epigenetics Congenital Diseases > Genetics/Genomics/Epigenetics Congenital Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Timir G R Weston
- Randall Centre for Cell & Molecular Biophysics, King's College London, London, UK
| | - Martin Rees
- Randall Centre for Cell & Molecular Biophysics, King's College London, London, UK
| | - Mathias Gautel
- Randall Centre for Cell & Molecular Biophysics, King's College London, London, UK
| | - Franca Fraternali
- Institute of Structural and Molecular Biology, University College London, London, UK
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2
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Tamborrini D, Wang Z, Wagner T, Tacke S, Stabrin M, Grange M, Kho AL, Rees M, Bennett P, Gautel M, Raunser S. Structure of the native myosin filament in the relaxed cardiac sarcomere. Nature 2023; 623:863-871. [PMID: 37914933 PMCID: PMC10665186 DOI: 10.1038/s41586-023-06690-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 09/28/2023] [Indexed: 11/03/2023]
Abstract
The thick filament is a key component of sarcomeres, the basic units of striated muscle1. Alterations in thick filament proteins are associated with familial hypertrophic cardiomyopathy and other heart and muscle diseases2. Despite the central importance of the thick filament, its molecular organization remains unclear. Here we present the molecular architecture of native cardiac sarcomeres in the relaxed state, determined by cryo-electron tomography. Our reconstruction of the thick filament reveals the three-dimensional organization of myosin, titin and myosin-binding protein C (MyBP-C). The arrangement of myosin molecules is dependent on their position along the filament, suggesting specialized capacities in terms of strain susceptibility and force generation. Three pairs of titin-α and titin-β chains run axially along the filament, intertwining with myosin tails and probably orchestrating the length-dependent activation of the sarcomere. Notably, whereas the three titin-α chains run along the entire length of the thick filament, titin-β chains do not. The structure also demonstrates that MyBP-C bridges thin and thick filaments, with its carboxy-terminal region binding to the myosin tails and directly stabilizing the OFF state of the myosin heads in an unforeseen manner. These results provide a foundation for future research investigating muscle disorders involving sarcomeric components.
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Affiliation(s)
- Davide Tamborrini
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Zhexin Wang
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Thorsten Wagner
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Sebastian Tacke
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Markus Stabrin
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Michael Grange
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
- Structural Biology, The Rosalind Franklin Institute, Didcot, UK
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Centre of Research Excellence, London, UK
| | - Martin Rees
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Centre of Research Excellence, London, UK
| | - Pauline Bennett
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Centre of Research Excellence, London, UK
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Centre of Research Excellence, London, UK
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
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3
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Wacker J, Di Bernardo S, Lobrinus JA, Jungbluth H, Gautel M, Beghetti M, Fluss J. Successful heart transplant in a child with congenital core myopathy and delayed-onset restrictive cardiomyopathy due to recessive mutations in the titin (TTN) gene. Pediatr Transplant 2023; 27:e14561. [PMID: 37345726 DOI: 10.1111/petr.14561] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 05/24/2023] [Accepted: 06/13/2023] [Indexed: 06/23/2023]
Abstract
BACKGROUND Mutations in the TTN gene, encoding the muscle filament titin, are a major cause of inherited dilated cardiomyopathy. Early-onset skeletal muscle disorders due to recessive TTN mutations have recently been described, sometimes associated with cardiomyopathies. CASE DESCRIPTION We report the case of a boy with congenital core myopathy due to compound heterozygosity for TTN variants. He presented in infancy with rapidly evolving restrictive cardiomyopathy, requiring heart transplantation at the age of 5 years with favorable long-term cardiac and neuromuscular outcome. CONCLUSION Heart transplantation may have a role in selected patients with TTN-related congenital myopathy with disproportionally severe cardiac presentation compared to skeletal and respiratory muscle involvement.
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Affiliation(s)
- Julie Wacker
- Pediatric Cardiology Unit, University Hospitals of Geneva, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Centre Universitaire Romand de Cardiologie et Chirurgie Cardiaque Pédiatrique, University Hospitals of Geneva, Geneva, Switzerland
| | - Stefano Di Bernardo
- Centre Universitaire Romand de Cardiologie et Chirurgie Cardiaque Pédiatrique, University Hospitals of Geneva, Geneva, Switzerland
- Pediatric Cardiology, Department of Pediatrics, Lausanne University Hospital, Lausanne, Switzerland
| | | | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Maurice Beghetti
- Pediatric Cardiology Unit, University Hospitals of Geneva, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Centre Universitaire Romand de Cardiologie et Chirurgie Cardiaque Pédiatrique, University Hospitals of Geneva, Geneva, Switzerland
| | - Joel Fluss
- Pediatric Neurology Unit, University Hospitals of Geneva, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Rees M, Nikoopour R, Alexandrovich A, Pfuhl M, Lopes LR, Akhtar MM, Syrris P, Elliott P, Carr-White G, Gautel M. Structure determination and analysis of titin A-band fibronectin type III domains provides insights for disease-linked variants and protein oligomerisation. J Struct Biol 2023; 215:108009. [PMID: 37549721 PMCID: PMC10862085 DOI: 10.1016/j.jsb.2023.108009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 07/06/2023] [Accepted: 08/03/2023] [Indexed: 08/09/2023]
Abstract
Titin is the largest protein found in nature and spans half a sarcomere in vertebrate striated muscle. The protein has multiple functions, including in the organisation of the thick filament and acting as a molecular spring during the muscle contraction cycle. Missense variants in titin have been linked to both cardiac and skeletal myopathies. Titin is primarily composed of tandem repeats of immunoglobulin and fibronectin type III (Fn3) domains in a variety of repeat patterns; however, the vast majority of these domains have not had their high-resolution structure determined experimentally. Here, we present the crystal structures of seven wild type titin Fn3 domains and two harbouring rare missense variants reported in hypertrophic cardiomyopathy (HCM) patients. All domains present the typical Fn3 fold, with the domains harbouring variants reported in HCM patients retaining the wild-type conformation. The effect on domain folding and stability were assessed for five rare missense variants found in HCM patients: four caused thermal destabilization of between 7 and 13 °C and one prevented the folding of its domain. The structures also allowed us to locate the positions of residues whose mutations have been linked to congenital myopathies and rationalise how they convey their deleterious effects. We find no evidence of physiological homodimer formation, excluding one hypothesised mechanism as to how titin variants could exert pathological effects.
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Affiliation(s)
- Martin Rees
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom.
| | - Roksana Nikoopour
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom
| | - Alexander Alexandrovich
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom
| | - Mark Pfuhl
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom; School of Cardiovascular Sciences and Medicine, King's College London, United Kingdom
| | - Luis R Lopes
- Institute of Cardiovascular Science, University College London, United Kingdom; Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom
| | - Mohammed M Akhtar
- Institute of Cardiovascular Science, University College London, United Kingdom
| | - Petros Syrris
- Institute of Cardiovascular Science, University College London, United Kingdom
| | - Perry Elliott
- Institute of Cardiovascular Science, University College London, United Kingdom; Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom
| | - Gerry Carr-White
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom; School of Biomedical Engineering and Imaging Sciences, Rayne Institute, King's College London, St Thomas' Hospital, London, United Kingdom
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom.
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5
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Koch D, Kho AL, Fukuzawa A, Alexandrovich A, Vanaanen KJ, Beavil A, Pfuhl M, Rees M, Gautel M. Obscurin Rho GEF domains are phosphorylated by MST-family kinases but do not exhibit nucleotide exchange factor activity towards Rho GTPases in vitro. PLoS One 2023; 18:e0284453. [PMID: 37079638 PMCID: PMC10118190 DOI: 10.1371/journal.pone.0284453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 04/01/2023] [Indexed: 04/21/2023] Open
Abstract
Obscurin is a giant muscle protein (>800 kDa) featuring multiple signalling domains, including an SH3-DH-PH domain triplet from the Trio-subfamily of guanosine nucleotide exchange factors (GEFs). While previous research suggests that these domains can activate the small GTPases RhoA and RhoQ in cells, in vitro characterization of these interactions using biophysical techniques has been hampered by the intrinsic instability of obscurin GEF domains. To study substrate specificity, mechanism and regulation of obscurin GEF function by individual domains, we successfully optimized recombinant production of obscurin GEF domains and found that MST-family kinases phosphorylate the obscurin DH domain at Thr5798. Despite extensive testing of multiple GEF domain fragments, we did not detect any nucleotide exchange activity in vitro against 9 representative small GTPases. Bioinformatic analyses show that obscurin differs from other Trio-subfamily GEFs in several important aspects. While further research is necessary to evaluate obscurin GEF activity in vivo, our results indicate that obscurin has atypical GEF domains that, if catalytically active at all, are subject to complex regulation.
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Affiliation(s)
- Daniel Koch
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Atsushi Fukuzawa
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Alexander Alexandrovich
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Kutti J. Vanaanen
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Andrew Beavil
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Mark Pfuhl
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Martin Rees
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
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6
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Broadway-Stringer S, Jiang H, Wadmore K, Hooper C, Douglas G, Steeples V, Azad AJ, Singer E, Reyat JS, Galatik F, Ehler E, Bennett P, Kalisch-Smith JI, Sparrow DB, Davies B, Djinovic-Carugo K, Gautel M, Watkins H, Gehmlich K. Insights into the Role of a Cardiomyopathy-Causing Genetic Variant in ACTN2. Cells 2023; 12:721. [PMID: 36899856 PMCID: PMC10001372 DOI: 10.3390/cells12050721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 02/13/2023] [Accepted: 02/21/2023] [Indexed: 03/12/2023] Open
Abstract
Pathogenic variants in ACTN2, coding for alpha-actinin 2, are known to be rare causes of Hypertrophic Cardiomyopathy. However, little is known about the underlying disease mechanisms. Adult heterozygous mice carrying the Actn2 p.Met228Thr variant were phenotyped by echocardiography. For homozygous mice, viable E15.5 embryonic hearts were analysed by High Resolution Episcopic Microscopy and wholemount staining, complemented by unbiased proteomics, qPCR and Western blotting. Heterozygous Actn2 p.Met228Thr mice have no overt phenotype. Only mature males show molecular parameters indicative of cardiomyopathy. By contrast, the variant is embryonically lethal in the homozygous setting and E15.5 hearts show multiple morphological abnormalities. Molecular analyses, including unbiased proteomics, identified quantitative abnormalities in sarcomeric parameters, cell-cycle defects and mitochondrial dysfunction. The mutant alpha-actinin protein is found to be destabilised, associated with increased activity of the ubiquitin-proteasomal system. This missense variant in alpha-actinin renders the protein less stable. In response, the ubiquitin-proteasomal system is activated; a mechanism that has been implicated in cardiomyopathies previously. In parallel, a lack of functional alpha-actinin is thought to cause energetic defects through mitochondrial dysfunction. This seems, together with cell-cycle defects, the likely cause of the death of the embryos. The defects also have wide-ranging morphological consequences.
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Affiliation(s)
| | - He Jiang
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford OX3 9DU, UK
| | - Kirsty Wadmore
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Charlotte Hooper
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford OX3 9DU, UK
| | - Gillian Douglas
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford OX3 9DU, UK
| | - Violetta Steeples
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford OX3 9DU, UK
| | - Amar J. Azad
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Evie Singer
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Jasmeet S. Reyat
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Frantisek Galatik
- Department of Physiology, Faculty of Science, Charles University, 12800 Prague, Czech Republic
| | - Elisabeth Ehler
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London SE1 9RT, UK
- School of Cardiovascular and Metabolic Medicine and Sciences, British Heart Foundation Centre of Research Excellence, King’s College London, London SE1 9RT, UK
| | - Pauline Bennett
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London SE1 9RT, UK
| | | | - Duncan B. Sparrow
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Benjamin Davies
- Transgenic Core, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Kristina Djinovic-Carugo
- European Molecular Biology Laboratory, 38000 Grenoble, France
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, 1030 Vienna, Austria
| | - Mathias Gautel
- School of Basic and Medical Biosciences, British Heart Foundation Centre of Research Excellence, King’s College London, London SE1 9RT, UK
| | - Hugh Watkins
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford OX3 9DU, UK
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham B15 2TT, UK
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford OX3 9DU, UK
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7
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Bennett P, Rees M, Grover S, Fukuzawa A, Alexandrovich A, Steiner R, Gautel M. The organisation of titin at the centre of the vertebrate striated muscle thick filament. Biophys J 2023; 122:28a-29a. [PMID: 36783437 DOI: 10.1016/j.bpj.2022.11.375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Pauline Bennett
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Martin Rees
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Sarah Grover
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Atsushi Fukuzawa
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Alexander Alexandrovich
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Roberto Steiner
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
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8
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Jiang H, Kalisch-Smith J, Sparrow D, Broadway-Stringer S, Wadmore K, Hooper C, Ehler E, Gautel M, Davies B, Watkins H, Gehmlich K. Small change, big impact: A Z-disc missense genetic variant causes dramatic morphological changes in the embryonic heart. J Mol Cell Cardiol 2022. [DOI: 10.1016/j.yjmcc.2022.08.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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9
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Santiago C, Huttner IG, Wang LW, Chand R, Cvetkovska J, Zhao G, Hesselson D, Hinits Y, O'Brien A, Feneley M, Smith K, Linke W, Gautel M, Fatkin D. Position-dependent effects of titin truncation on the heart. J Mol Cell Cardiol 2022. [DOI: 10.1016/j.yjmcc.2022.08.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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10
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Gehmlich K, Jiang A, Wadmore K, Hooper C, Douglas G, Ehler E, Broadway-Stringer S, Kalisch-Smith J, Sparrow D, Gautel M, Davies B, Watkins H. Crucial functions of alpha-actinin 2 in the embryonic heart. Cardiovasc Res 2022. [DOI: 10.1093/cvr/cvac066.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): Wellcome Trust; British Heart Foundation
Background/Introduction
Alpha-actinin is an integral protein of the Z-discs in heart and skeletal muscle cells, with important structural and signalling functions. Missense variants in alpha-actinin can cause inherited conditions, e.g. myopathies and cardiomyopathies. The underlying disease mechanisms are still unknown.
Purpose
In order to study the disease mechanisms of an alpha-actinin missense variant, which is known to cause Hypertrophic Cardiomyopathy in human patients, a mouse model was generated.
Methods
Mice carrying the alpha-actinin missense variant were generated by CRISPR-Cas9 genome editing. The heterozygous adult mice carrying the alpha-actinin variant were characterised by echocardiography and quantitative PCR. Hearts of homozygous embryos were analysed at E15.5 by high-resolution episcopic microscopy (HREM).
Results
Mice carrying a single copy of the missense variant were viable and had normal appearance. Adult heterozygous mice showed no signs of cardiomyopathy on echocardiography. However, mature male mice displayed molecular signs of cardiomyopathy, such as induction of the fetal gene programme at transcript level.
The attempt to generate adult mice homozygous for the variant failed: 9 breeding pairs produced 18 litters with 83 weaned pups, but no homozygous offspring. Embryonic lethality was confirmed and E15.5 was the latest stage homozygous pups were reliably found to be viable. At this timepoint, genotype distribution was within the expected Mendelian ratios.
HREM of the hearts at this stage revealed increased right ventricular chamber size and decreased left atrial size, when compared to wildtype littermates. Membranous ventricular septal defects were observed in 3 out of 8 homozygous hearts. Further these embryos displayed aortic stenosis and dysplasic leaflets of the pulmonary valve.
Conclusions
Heterozygous adult mice only displayed sub-clinical signs of disease. In contrast, the missense variant is embryonic lethal in the homozygous setting and leads to a range of morphological abnormalities in E15.5 hearts. Future work will identify how altered functions of alpha-actinin cause these changes.
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Affiliation(s)
- K Gehmlich
- Institute of Cardiovascular Sciences , Birmingham , United Kingdom of Great Britain & Northern Ireland
| | - A Jiang
- University of Oxford, Cardiovascular Medicine , Oxford , United Kingdom of Great Britain & Northern Ireland
| | - K Wadmore
- Institute of Cardiovascular Sciences , Birmingham , United Kingdom of Great Britain & Northern Ireland
| | - C Hooper
- University of Oxford, Cardiovascular Medicine , Oxford , United Kingdom of Great Britain & Northern Ireland
| | - G Douglas
- University of Oxford, Cardiovascular Medicine , Oxford , United Kingdom of Great Britain & Northern Ireland
| | - E Ehler
- King's College London , London , United Kingdom of Great Britain & Northern Ireland
| | - S Broadway-Stringer
- Institute of Cardiovascular Sciences , Birmingham , United Kingdom of Great Britain & Northern Ireland
| | - J Kalisch-Smith
- University of Oxford, Department of Physiology, Anatomy and Genetics , Oxford , United Kingdom of Great Britain & Northern Ireland
| | - D Sparrow
- University of Oxford, Department of Physiology, Anatomy and Genetics , Oxford , United Kingdom of Great Britain & Northern Ireland
| | - M Gautel
- King's College London , London , United Kingdom of Great Britain & Northern Ireland
| | - B Davies
- University of Oxford, Wellcome Centre for Human Genetics , Oxford , United Kingdom of Great Britain & Northern Ireland
| | - H Watkins
- University of Oxford, Cardiovascular Medicine , Oxford , United Kingdom of Great Britain & Northern Ireland
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11
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Deneubourg C, Ramm M, Smith LJ, Baron O, Singh K, Byrne SC, Duchen MR, Gautel M, Eskelinen EL, Fanto M, Jungbluth H. The spectrum of neurodevelopmental, neuromuscular and neurodegenerative disorders due to defective autophagy. Autophagy 2022; 18:496-517. [PMID: 34130600 PMCID: PMC9037555 DOI: 10.1080/15548627.2021.1943177] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 06/10/2021] [Indexed: 12/15/2022] Open
Abstract
Primary dysfunction of autophagy due to Mendelian defects affecting core components of the autophagy machinery or closely related proteins have recently emerged as an important cause of genetic disease. This novel group of human disorders may present throughout life and comprises severe early-onset neurodevelopmental and more common adult-onset neurodegenerative disorders. Early-onset (or congenital) disorders of autophagy often share a recognizable "clinical signature," including variable combinations of neurological, neuromuscular and multisystem manifestations. Structural CNS abnormalities, cerebellar involvement, spasticity and peripheral nerve pathology are prominent neurological features, indicating a specific vulnerability of certain neuronal populations to autophagic disturbance. A typically biphasic disease course of late-onset neurodegeneration occurring on the background of a neurodevelopmental disorder further supports a role of autophagy in both neuronal development and maintenance. Additionally, an associated myopathy has been characterized in several conditions. The differential diagnosis comprises a wide range of other multisystem disorders, including mitochondrial, glycogen and lysosomal storage disorders, as well as ciliopathies, glycosylation and vesicular trafficking defects. The clinical overlap between the congenital disorders of autophagy and these conditions reflects the multiple roles of the proteins and/or emerging molecular connections between the pathways implicated and suggests an exciting area for future research. Therapy development for congenital disorders of autophagy is still in its infancy but may result in the identification of molecules that target autophagy more specifically than currently available compounds. The close connection with adult-onset neurodegenerative disorders highlights the relevance of research into rare early-onset neurodevelopmental conditions for much more common, age-related human diseases.Abbreviations: AC: anterior commissure; AD: Alzheimer disease; ALR: autophagic lysosomal reformation; ALS: amyotrophic lateral sclerosis; AMBRA1: autophagy and beclin 1 regulator 1; AMPK: AMP-activated protein kinase; ASD: autism spectrum disorder; ATG: autophagy related; BIN1: bridging integrator 1; BPAN: beta-propeller protein associated neurodegeneration; CC: corpus callosum; CHMP2B: charged multivesicular body protein 2B; CHS: Chediak-Higashi syndrome; CMA: chaperone-mediated autophagy; CMT: Charcot-Marie-Tooth disease; CNM: centronuclear myopathy; CNS: central nervous system; DNM2: dynamin 2; DPR: dipeptide repeat protein; DVL3: disheveled segment polarity protein 3; EPG5: ectopic P-granules autophagy protein 5 homolog; ER: endoplasmic reticulum; ESCRT: homotypic fusion and protein sorting complex; FIG4: FIG4 phosphoinositide 5-phosphatase; FTD: frontotemporal dementia; GBA: glucocerebrosidase; GD: Gaucher disease; GRN: progranulin; GSD: glycogen storage disorder; HC: hippocampal commissure; HD: Huntington disease; HOPS: homotypic fusion and protein sorting complex; HSPP: hereditary spastic paraparesis; LAMP2A: lysosomal associated membrane protein 2A; MEAX: X-linked myopathy with excessive autophagy; mHTT: mutant huntingtin; MSS: Marinesco-Sjoegren syndrome; MTM1: myotubularin 1; MTOR: mechanistic target of rapamycin kinase; NBIA: neurodegeneration with brain iron accumulation; NCL: neuronal ceroid lipofuscinosis; NPC1: Niemann-Pick disease type 1; PD: Parkinson disease; PtdIns3P: phosphatidylinositol-3-phosphate; RAB3GAP1: RAB3 GTPase activating protein catalytic subunit 1; RAB3GAP2: RAB3 GTPase activating non-catalytic protein subunit 2; RB1: RB1-inducible coiled-coil protein 1; RHEB: ras homolog, mTORC1 binding; SCAR20: SNX14-related ataxia; SENDA: static encephalopathy of childhood with neurodegeneration in adulthood; SNX14: sorting nexin 14; SPG11: SPG11 vesicle trafficking associated, spatacsin; SQSTM1: sequestosome 1; TBC1D20: TBC1 domain family member 20; TECPR2: tectonin beta-propeller repeat containing 2; TSC1: TSC complex subunit 1; TSC2: TSC complex subunit 2; UBQLN2: ubiquilin 2; VCP: valosin-containing protein; VMA21: vacuolar ATPase assembly factor VMA21; WDFY3/ALFY: WD repeat and FYVE domain containing protein 3; WDR45: WD repeat domain 45; WDR47: WD repeat domain 47; WMS: Warburg Micro syndrome; XLMTM: X-linked myotubular myopathy; ZFYVE26: zinc finger FYVE-type containing 26.
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Affiliation(s)
- Celine Deneubourg
- Department of Basic and Clinical Neuroscience, IoPPN, King’s College London, London, UK
| | - Mauricio Ramm
- Institute of Biomedicine, University of Turku, Turku, Finland
| | - Luke J. Smith
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King’s College London, London, UK
| | - Olga Baron
- Wolfson Centre for Age-Related Diseases, King’s College London, London, UK
| | - Kritarth Singh
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Susan C. Byrne
- Department of Paediatric Neurology, Neuromuscular Service, Evelina’s Children Hospital, Guy’s & St. Thomas’ Hospital NHS Foundation Trust, London, UK
| | - Michael R. Duchen
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King’s College London, London, UK
| | - Eeva-Liisa Eskelinen
- Institute of Biomedicine, University of Turku, Turku, Finland
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Manolis Fanto
- Department of Basic and Clinical Neuroscience, IoPPN, King’s College London, London, UK
| | - Heinz Jungbluth
- Department of Basic and Clinical Neuroscience, IoPPN, King’s College London, London, UK
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King’s College London, London, UK
- Department of Paediatric Neurology, Neuromuscular Service, Evelina’s Children Hospital, Guy’s & St. Thomas’ Hospital NHS Foundation Trust, London, UK
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12
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Wang Z, Grange M, Pospich S, Wagner T, Kho AL, Gautel M, Raunser S. Structures from intact myofibrils reveal mechanism of thin filament regulation through nebulin. Science 2022; 375:eabn1934. [PMID: 35175800 DOI: 10.1126/science.abn1934] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In skeletal muscle, nebulin stabilizes and regulates the length of thin filaments, but the underlying mechanism remains nebulous. In this work, we used cryo-electron tomography and subtomogram averaging to reveal structures of native nebulin bound to thin filaments within intact sarcomeres. This in situ reconstruction provided high-resolution details of the interaction between nebulin and actin, demonstrating the stabilizing role of nebulin. Myosin bound to the thin filaments exhibited different conformations of the neck domain, highlighting its inherent structural variability in muscle. Unexpectedly, nebulin did not interact with myosin or tropomyosin, but it did interact with a troponin T linker through two potential binding motifs on nebulin, explaining its regulatory role. Our structures support the role of nebulin as a thin filament "molecular ruler" and provide a molecular basis for studying nemaline myopathies.
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Affiliation(s)
- Zhexin Wang
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Michael Grange
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Sabrina Pospich
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Thorsten Wagner
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Centre of Research Excellence, Guy's Campus, London SE1 1UL, UK
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Centre of Research Excellence, Guy's Campus, London SE1 1UL, UK
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
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13
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Filomena MC, Yamamoto DL, Carullo P, Medvedev R, Ghisleni A, Piroddi N, Scellini B, Crispino R, D'Autilia F, Zhang J, Felicetta A, Nemska S, Serio S, Tesi C, Catalucci D, Linke WA, Polishchuk R, Poggesi C, Gautel M, Bang ML. Myopalladin knockout mice develop cardiac dilation and show a maladaptive response to mechanical pressure overload. eLife 2021; 10:e58313. [PMID: 34558411 PMCID: PMC8547954 DOI: 10.7554/elife.58313] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/23/2021] [Indexed: 12/13/2022] Open
Abstract
Myopalladin (MYPN) is a striated muscle-specific immunoglobulin domain-containing protein located in the sarcomeric Z-line and I-band. MYPN gene mutations are causative for dilated (DCM), hypertrophic, and restrictive cardiomyopathy. In a yeast two-hybrid screening, MYPN was found to bind to titin in the Z-line, which was confirmed by microscale thermophoresis. Cardiac analyses of MYPN knockout (MKO) mice showed the development of mild cardiac dilation and systolic dysfunction, associated with decreased myofibrillar isometric tension generation and increased resting tension at longer sarcomere lengths. MKO mice exhibited a normal hypertrophic response to transaortic constriction (TAC), but rapidly developed severe cardiac dilation and systolic dysfunction, associated with fibrosis, increased fetal gene expression, higher intercalated disc fold amplitude, decreased calsequestrin-2 protein levels, and increased desmoplakin and SORBS2 protein levels. Cardiomyocyte analyses showed delayed Ca2+ release and reuptake in unstressed MKO mice as well as reduced Ca2+ spark amplitude post-TAC, suggesting that altered Ca2+ handling may contribute to the development of DCM in MKO mice.
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Affiliation(s)
- Maria Carmela Filomena
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
| | - Daniel L Yamamoto
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
| | - Pierluigi Carullo
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
| | - Roman Medvedev
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Cardiac Surgery, University of VeronaVeronaItaly
| | - Andrea Ghisleni
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research ExcellenceLondonUnited Kingdom
| | - Nicoletta Piroddi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Beatrice Scellini
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Roberta Crispino
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | | | - Jianlin Zhang
- Department of Medicine, University of California, San DiegoLa JollaUnited States
| | - Arianna Felicetta
- IRCCS Humanitas Research HospitalMilanItaly
- Humanitas UniversityPieve EmanueleItaly
| | | | | | - Chiara Tesi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | | | - Wolfgang A Linke
- Institute of Physiology II, University of MuensterMuensterGermany
| | - Roman Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | - Corrado Poggesi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research ExcellenceLondonUnited Kingdom
| | - Marie-Louise Bang
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
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14
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Sponga A, Arolas JL, Schwarz TC, Jeffries CM, Rodriguez Chamorro A, Kostan J, Ghisleni A, Drepper F, Polyansky A, De Almeida Ribeiro E, Pedron M, Zawadzka-Kazimierczuk A, Mlynek G, Peterbauer T, Doto P, Schreiner C, Hollerl E, Mateos B, Geist L, Faulkner G, Kozminski W, Svergun DI, Warscheid B, Zagrovic B, Gautel M, Konrat R, Djinović-Carugo K. Order from disorder in the sarcomere: FATZ forms a fuzzy complex and phase-separated macromolecular condensates with α-actinin. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321093946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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15
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Savarese M, Vihola A, Jokela ME, Huovinen SP, Gerevini S, Torella A, Johari M, Scarlato M, Jonson PH, Onore ME, Hackman P, Gautel M, Nigro V, Previtali SC, Udd B. Out-of-Frame Mutations in ACTN2 Last Exon Cause a Dominant Distal Myopathy With Facial Weakness. Neurol Genet 2021; 7:e619. [PMID: 34386585 PMCID: PMC8356702 DOI: 10.1212/nxg.0000000000000619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 07/01/2021] [Indexed: 11/18/2022]
Abstract
Background and Objectives To clinically, genetically, and histopathologically characterize patients presenting with an unusual combination of distal myopathy and facial weakness, without involvement of upper limb or shoulder girdle muscles. Methods Two families with a novel form of actininopathy were identified. Patients had been followed up over 10 years. Their molecular genetic diagnosis was not clear after extensive investigations, including analysis of candidate genes and FSHD1-related D4Z4 repeats. Results Patients shared a similar clinical phenotype and a common pattern of muscle involvement. They presented with a very slowly progressive myopathy involving anterior lower leg and facial muscles. Muscle MRI finding showed complete fat replacement of anterolateral compartment muscles of the lower legs with variable involvement of soleus and gastrocnemius but sparing thigh muscles. Muscle biopsy showed internalized nuclei, myofibrillar disorganization, and rimmed vacuoles. High-throughput sequencing identified in each proband a heterozygous single nucleotide deletion (c.2558del and c.2567del) in the last exon of the ACTN2 gene. The deletions are predicted to lead to a novel but unstructured slightly extended C-terminal amino acid sequence. Discussion Our findings indicate an unusual form of actininopathy with specific molecular and clinical features. Actininopathy should be considered in the differential diagnosis of distal myopathy combined with facial weakness.
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Affiliation(s)
- Marco Savarese
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Anna Vihola
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Manu E Jokela
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Sanna Pauliina Huovinen
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Simonetta Gerevini
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Annalaura Torella
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Mridul Johari
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Marina Scarlato
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Per Harald Jonson
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Maria Elena Onore
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Peter Hackman
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Mathias Gautel
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Vincenzo Nigro
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Stefano Carlo Previtali
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
| | - Bjarne Udd
- Folkhälsan Research Center (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Helsinki; Department of Medical Genetics (M. Savarese, A.V., M.J., P.H.J., P.H., B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (A.V.), Department of Genetics, Fimlab Laboratories, Tampere; Division of Clinical Neurosciences (M.E.J.), Department of Neurology, Turku University and University Hospital; Neuromuscular Research Center (S.P.H.), Department of Pathology, Fimlab Laboratories, Tampere, Finland; Neuroradiology Unit (S.G.), ASST Papa Giovanni XXIII, Bergamo; Dipartimento di Medicina di Precisione (A.T., M.E.O., V.N.), Università degli Studi della Campania "Luigi Vanvitelli," Napoli; Telethon Institute of Genetics and Medicine (A.T., V.N.), Pozzuoli; Division of Neuroscience and U.O. Neurologia (M. Scarlato, S.C.P.), IRCCS Ospedale San Raffaele, Milano, Italy; Randall Centre for Cell and Molecular Biophysics (M.G.), King's College London BHF Centre of Research Excellence, United Kingdom; Department of Neurology (B.U.), Vaasa Central Hospital; and Neuromuscular Research Center (M.E.J., B.U.), Department of Neurology, Tampere University and University Hospital, Finland
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16
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Akhtar MM, Lorenzini M, Pavlou M, Ochoa JP, O’Mahony C, Restrepo-Cordoba MA, Segura-Rodriguez D, Bermúdez-Jiménez F, Molina P, Cuenca S, Ader F, Larrañaga-Moreira JM, Sabater-Molina M, Garcia-Alvarez MI, Arantzamendi LG, Truszkowska G, Ortiz-Genga M, Ruiz IS, Nielsen SK, Rasmussen TB, Robles Mezcua A, Alvarez-Rubio J, Eiskjaer H, Gautel M, Garcia-Pinilla JM, Ripoll-Vera T, Mogensen J, Limeres Freire J, Rodríguez-Palomares JF, Peña-Peña ML, Rangel-Sousa D, Palomino-Doza J, Arana Achaga X, Bilinska Z, Zamarreño Golvano E, Climent V, Peñalver MN, Barriales-Villa R, Charron P, Yotti R, Zorio E, Jiménez-Jáimez J, Garcia-Pavia P, Elliott PM. Association of Left Ventricular Systolic Dysfunction Among Carriers of Truncating Variants in Filamin C With Frequent Ventricular Arrhythmia and End-stage Heart Failure. JAMA Cardiol 2021; 6:891-901. [PMID: 33978673 PMCID: PMC8117057 DOI: 10.1001/jamacardio.2021.1106] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 02/22/2021] [Indexed: 12/28/2022]
Abstract
Importance Truncating variants in the gene encoding filamin C (FLNCtv) are associated with arrhythmogenic and dilated cardiomyopathies with a reportedly high risk of ventricular arrhythmia. Objective To determine the frequency of and risk factors associated with adverse events among FLNCtv carriers compared with individuals carrying TTN truncating variants (TTNtv). Design, Setting, and Participants This cohort study recruited 167 consecutive FLNCtv carriers and a control cohort of 244 patients with TTNtv matched for left ventricular ejection fraction (LVEF) from 19 European cardiomyopathy referral units between 1990 and 2018. Data analyses were conducted between June and October, 2020. Main Outcomes and Measures The primary end point was a composite of malignant ventricular arrhythmia (MVA) (sudden cardiac death, aborted sudden cardiac death, appropriate implantable cardioverter-defibrillator shock, and sustained ventricular tachycardia) and end-stage heart failure (heart transplant or mortality associated with end-stage heart failure). The secondary end point comprised MVA events only. Results In total, 167 patients with FLNCtv were studied (55 probands [33%]; 89 men [53%]; mean [SD] age at baseline evaluation, 43 [18] years). For a median follow-up of 20 months (interquartile range, 7-60 months), 29 patients (17.4%) reached the primary end point (19 patients with MVA and 10 patients with end-stage heart failure). Eight (44%) arrhythmic events occurred among individuals with baseline mild to moderate left ventricular systolic dysfunction (LVSD) (LVEF = 36%-49%). Univariable risk factors associated with the primary end point included proband status, LVEF decrement per 10%, ventricular ectopy (≥500 in 24 hours) and myocardial fibrosis detected on cardiac magnetic resonance imaging. The LVEF decrement (hazard ratio [HR] per 10%, 1.83 [95% CI, 1.30-2.57]; P < .001) and proband status (HR, 3.18 [95% CI, 1.12-9.04]; P = .03) remained independent risk factors on multivariable analysis (excluding myocardial fibrosis and ventricular ectopy owing to case censoring). There was no difference in freedom from MVA between FLNCtv carriers with mild to moderate or severe (LVEF ≤35%) LVSD (HR, 1.29 [95% CI, 0.45-3.72]; P = .64). Carriers of FLNCtv with impaired LVEF at baseline evaluation (n = 69) had reduced freedom from MVA compared with 244 TTNtv carriers with similar baseline LVEF (for mild to moderate LVSD: HR, 16.41 [95% CI, 3.45-78.11]; P < .001; for severe LVSD: HR, 2.47 [95% CI, 1.04-5.87]; P = .03). Conclusions and Relevance The high frequency of MVA among patients with FLNCtv with mild to moderate LVSD suggests that higher LVEF values than those currently recommended should be considered for prophylactic implantable cardioverter-defibrillator therapy in FLNCtv carriers.
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MESH Headings
- Adult
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/mortality
- Cardiomyopathy, Dilated/physiopathology
- Cardiomyopathy, Dilated/therapy
- Codon, Nonsense
- Connectin/genetics
- Death, Sudden, Cardiac/prevention & control
- Defibrillators, Implantable
- Female
- Filamins/genetics
- Heart Failure/genetics
- Heart Failure/mortality
- Heart Failure/physiopathology
- Heart Failure/therapy
- Heart Transplantation/statistics & numerical data
- Humans
- Male
- Middle Aged
- Mutation
- Stroke Volume
- Tachycardia, Ventricular/epidemiology
- Tachycardia, Ventricular/genetics
- Tachycardia, Ventricular/physiopathology
- Ventricular Dysfunction, Left/genetics
- Ventricular Dysfunction, Left/physiopathology
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Affiliation(s)
- Mohammed Majid Akhtar
- Department of Inherited Cardiovascular Diseases, Bart’s Heart Centre St Bartholomew’s Hospital, London, United Kingdom
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Massimiliano Lorenzini
- Department of Inherited Cardiovascular Diseases, Bart’s Heart Centre St Bartholomew’s Hospital, London, United Kingdom
| | - Menelaos Pavlou
- Department of Statistical Science, University College London, London, United Kingdom
| | | | - Constantinos O’Mahony
- Department of Inherited Cardiovascular Diseases, Bart’s Heart Centre St Bartholomew’s Hospital, London, United Kingdom
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Maria Alejandra Restrepo-Cordoba
- Department of Cardiology, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Spain
- Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro, Madrid, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARDHEART)
| | | | | | - Pilar Molina
- Pathology Department, Institute of Legal Medicine and Forensic Sciences of Valencia and Faculty of Medicine of the Universitat de València, CAFAMUSME Research Group, IIS La Fe, Valencia, Spain
| | - Sofia Cuenca
- Hospital General Universitario Gregorio Marañon, Madrid, Spain
- Instituto de Investigación Sanitarias Gregorio Marañón, Spain
| | - Flavie Ader
- APHP, UF Cardiogénétique et Myogénétique, Service de Biochimie Métabolique, Hôpitaux Universitaires de la Pitié- Salpêtrière- Charles Foix, 47-83 Bd de l’Hôpital, Paris, France
- Sorbonne Universités, UPMC Univ. Paris 06, INSERM, UMR_S 1166 and ICAN Institute for Cardiometabolism and Nutrition, Paris, France
| | - Jose M. Larrañaga-Moreira
- Unidad de Cardiopatías Familiares, Instituto de Investigación Biomédica de A Coruña (INIBIC), A Coruña, Spain
- Complexo Hospitalario Universitario de A Coruña, Servizo Galego de Saúde (SERGAS), A Coruña, Spain
- Department of Cardiology, Universidade da Coruña, A Coruña, Spain
- Centro de Investigación Biomédica en Red (CIBERCV), Madrid, Spain
| | - Maria Sabater-Molina
- Inherited Cardiac Disease Unit, Hospital Universitario Virgen Arrixaca, Murcia, Spain
- Universidad de Murcia, Murcia, Spain
| | - Maria I. Garcia-Alvarez
- Cardiology Department, University General Hospital of Alicante, Alicante, Spain
- Institute of Health and Biomedical Research (ISABIAL), Alicante, Spain
| | | | - Grazyna Truszkowska
- Molecular Biology Laboratory, Department of Medical Biology, The Cardinal Stefan Wyszynski Institute of Cardiology, Warsaw, Poland
| | | | - Itziar Solla Ruiz
- Cardiology Specialist in Heart Failure and Inherited Cardiac Diseases, Department of Cardiology, Hospital Universitario Donostia, Spain
| | | | | | - Ainhoa Robles Mezcua
- Heart Failure and Familial Heart Diseases Unit, Cardiology Department, Hospital Universitario Virgen de la Victoria, CIBER-CV, IBIMA, Malaga, Spain
| | - Jorge Alvarez-Rubio
- Inherited Cardiovascular Diseases Unit, Son Llatzer University Hospital & IdISBa, Palma de Mallorca, Spain
| | - Hans Eiskjaer
- Department of Cardiology, Aarhus University Hospital, Hjertesygdomme, Aarhus, Denmark
| | - Mathias Gautel
- Randall Institute, King’s College London, London, United Kingdom
| | - José M. Garcia-Pinilla
- Heart Failure and Familial Heart Diseases Unit, Cardiology Department, Hospital Universitario Virgen de la Victoria, CIBER-CV, IBIMA, Malaga, Spain
| | - Tomas Ripoll-Vera
- Inherited Cardiovascular Diseases Unit, Son Llatzer University Hospital & IdISBa, Palma de Mallorca, Spain
| | - Jens Mogensen
- Department of Cardiology, Odense University Hospital, Odense, Denmark
| | - Javier Limeres Freire
- Department of Cardiology, Vall d’ Hebron Institut de Recerca (VHIR), Hospital Universitari Vall d’ Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jose F. Rodríguez-Palomares
- Department of Cardiology, Vall d’ Hebron Institut de Recerca (VHIR), Hospital Universitari Vall d’ Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Maria Luisa Peña-Peña
- Heart Failure and Heart Transplantation Unit, Virgen del Rocio University Hospital, Sevilla, Spain
| | - Diego Rangel-Sousa
- Heart Failure and Heart Transplantation Unit, Virgen del Rocio University Hospital, Sevilla, Spain
| | - Julian Palomino-Doza
- Hereditary Cardiopathies Unit, Hospital Universitario 12 de Octubre, Madrid, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Instituto de Investigación 12 de Octubre i+12, Madrid, Spain
| | - Xabier Arana Achaga
- Cardiology Specialist in Heart Failure and Inherited Cardiac Diseases, Department of Cardiology, Hospital Universitario Donostia, Spain
| | - Zofia Bilinska
- Unit for Screening Studies in Inherited Cardiovascular Diseases, The Cardinal Stefan Wyszynski Institute of Cardiology, Warsaw, Poland
| | | | - Vincent Climent
- Cardiology Department, University General Hospital of Alicante, Alicante, Spain
- Institute of Health and Biomedical Research (ISABIAL), Alicante, Spain
| | | | - Roberto Barriales-Villa
- Unidad de Cardiopatías Familiares, Instituto de Investigación Biomédica de A Coruña (INIBIC), A Coruña, Spain
- Complexo Hospitalario Universitario de A Coruña, Servizo Galego de Saúde (SERGAS), A Coruña, Spain
- Department of Cardiology, Universidade da Coruña, A Coruña, Spain
- Centro de Investigación Biomédica en Red (CIBERCV), Madrid, Spain
| | - Philippe Charron
- Sorbonne Universités, UPMC Univ. Paris 06, INSERM, UMR_S 1166 and ICAN Institute for Cardiometabolism and Nutrition, Paris, France
- APHP, Centre de Référence pour les Maladies Cardiaques Héréditaires, Département de Génétique, Hôpital Pitié-Salpêtrière, Paris, France
| | - Raquel Yotti
- Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Hospital General Universitario Gregorio Marañon, Madrid, Spain
- Instituto de Investigación Sanitarias Gregorio Marañón, Spain
| | - Esther Zorio
- Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Cardiology Department at Hospital Universitario y Politécnico La Fe and Research Group on Inherited Heart Diseases, Sudden Death and Mechanisms of Disease (CaFaMuSMe) from the Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | - Juan Jiménez-Jáimez
- Cardiology Department, Hospital Universitario Virgen de las Nieves, Granada, Spain
| | - Pablo Garcia-Pavia
- Department of Cardiology, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Spain
- Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro, Madrid, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARDHEART)
| | - Perry M. Elliott
- Department of Inherited Cardiovascular Diseases, Bart’s Heart Centre St Bartholomew’s Hospital, London, United Kingdom
- Institute of Cardiovascular Science, University College London, London, United Kingdom
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17
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Koch D, Alexandrovich A, Funk F, Kho AL, Schmitt JP, Gautel M. Molecular noise filtering in the β-adrenergic signaling network by phospholamban pentamers. Cell Rep 2021; 36:109448. [PMID: 34320358 PMCID: PMC8333238 DOI: 10.1016/j.celrep.2021.109448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 04/16/2021] [Accepted: 07/05/2021] [Indexed: 02/07/2023] Open
Abstract
Phospholamban (PLN) is an important regulator of cardiac calcium handling due to its ability to inhibit the calcium ATPase SERCA. β-Adrenergic stimulation reverses SERCA inhibition via PLN phosphorylation and facilitates fast calcium reuptake. PLN also forms pentamers whose physiological significance has remained elusive. Using mathematical modeling combined with biochemical and cell biological experiments, we show that pentamers regulate both the dynamics and steady-state levels of monomer phosphorylation. Substrate competition by pentamers and a feed-forward loop involving inhibitor-1 can delay monomer phosphorylation by protein kinase A (PKA), whereas cooperative pentamer dephosphorylation enables bistable PLN steady-state phosphorylation. Simulations show that phosphorylation delay and bistability act as complementary filters that reduce the effect of random fluctuations in PKA activity, thereby ensuring consistent monomer phosphorylation and SERCA activity despite noisy upstream signals. Preliminary analyses suggest that the PLN mutation R14del could impair noise filtering, offering a new perspective on how this mutation causes cardiac arrhythmias.
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Affiliation(s)
- Daniel Koch
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL London, UK.
| | | | - Florian Funk
- Institute of Pharmacology and Clinical Pharmacology, and Cardiovascular Research Institute Düsseldorf (CARID), University Hospital Düsseldorf, 40225 Düsseldorf, Germany
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL London, UK
| | - Joachim P Schmitt
- Institute of Pharmacology and Clinical Pharmacology, and Cardiovascular Research Institute Düsseldorf (CARID), University Hospital Düsseldorf, 40225 Düsseldorf, Germany
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL London, UK
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18
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Sponga A, Arolas JL, Schwarz TC, Jeffries CM, Rodriguez Chamorro A, Kostan J, Ghisleni A, Drepper F, Polyansky A, De Almeida Ribeiro E, Pedron M, Zawadzka-Kazimierczuk A, Mlynek G, Peterbauer T, Doto P, Schreiner C, Hollerl E, Mateos B, Geist L, Faulkner G, Kozminski W, Svergun DI, Warscheid B, Zagrovic B, Gautel M, Konrat R, Djinović-Carugo K. Order from disorder in the sarcomere: FATZ forms a fuzzy but tight complex and phase-separated condensates with α-actinin. Sci Adv 2021; 7:eabg7653. [PMID: 34049882 PMCID: PMC8163081 DOI: 10.1126/sciadv.abg7653] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/13/2021] [Indexed: 05/03/2023]
Abstract
In sarcomeres, α-actinin cross-links actin filaments and anchors them to the Z-disk. FATZ (filamin-, α-actinin-, and telethonin-binding protein of the Z-disk) proteins interact with α-actinin and other core Z-disk proteins, contributing to myofibril assembly and maintenance. Here, we report the first structure and its cellular validation of α-actinin-2 in complex with a Z-disk partner, FATZ-1, which is best described as a conformational ensemble. We show that FATZ-1 forms a tight fuzzy complex with α-actinin-2 and propose an interaction mechanism via main molecular recognition elements and secondary binding sites. The obtained integrative model reveals a polar architecture of the complex which, in combination with FATZ-1 multivalent scaffold function, might organize interaction partners and stabilize α-actinin-2 preferential orientation in Z-disk. Last, we uncover FATZ-1 ability to phase-separate and form biomolecular condensates with α-actinin-2, raising the question whether FATZ proteins can create an interaction hub for Z-disk proteins through membraneless compartmentalization during myofibrillogenesis.
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Affiliation(s)
- Antonio Sponga
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Joan L Arolas
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Thomas C Schwarz
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Cy M Jeffries
- European Molecular Biology Laboratory (EMBL), Hamburg Unit, Hamburg, Germany
| | - Ariadna Rodriguez Chamorro
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Julius Kostan
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Andrea Ghisleni
- King's College London BHF Centre for Research Excellence, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK
| | - Friedel Drepper
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Anton Polyansky
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
- National Research University Higher School of Economics, Moscow 101000, Russia
| | - Euripedes De Almeida Ribeiro
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Miriam Pedron
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Anna Zawadzka-Kazimierczuk
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Georg Mlynek
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Thomas Peterbauer
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Dr. BohrGasse 9, A-1030 Vienna, Austria
| | - Pierantonio Doto
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Claudia Schreiner
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Eneda Hollerl
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Borja Mateos
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Leonhard Geist
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | | | - Wiktor Kozminski
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Dmitri I Svergun
- King's College London BHF Centre for Research Excellence, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK
| | - Bettina Warscheid
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Bojan Zagrovic
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Mathias Gautel
- King's College London BHF Centre for Research Excellence, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK
| | - Robert Konrat
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria.
- Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
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Wang Z, Grange M, Wagner T, Kho AL, Gautel M, Raunser S. The molecular basis for sarcomere organization in vertebrate skeletal muscle. Cell 2021; 184:2135-2150.e13. [PMID: 33765442 PMCID: PMC8054911 DOI: 10.1016/j.cell.2021.02.047] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/27/2021] [Accepted: 02/22/2021] [Indexed: 12/20/2022]
Abstract
Sarcomeres are force-generating and load-bearing devices of muscles. A precise molecular picture of how sarcomeres are built underpins understanding their role in health and disease. Here, we determine the molecular architecture of native vertebrate skeletal sarcomeres by electron cryo-tomography. Our reconstruction reveals molecular details of the three-dimensional organization and interaction of actin and myosin in the A-band, I-band, and Z-disc and demonstrates that α-actinin cross-links antiparallel actin filaments by forming doublets with 6-nm spacing. Structures of myosin, tropomyosin, and actin at ~10 Å further reveal two conformations of the "double-head" myosin, where the flexible orientation of the lever arm and light chains enable myosin not only to interact with the same actin filament, but also to split between two actin filaments. Our results provide unexpected insights into the fundamental organization of vertebrate skeletal muscle and serve as a strong foundation for future investigations of muscle diseases.
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Affiliation(s)
- Zhexin Wang
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Michael Grange
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Thorsten Wagner
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Ay Lin Kho
- The Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Excellence Centre, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Mathias Gautel
- The Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Excellence Centre, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
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20
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Rees M, Nikoopour R, Fukuzawa A, Kho AL, Fernandez-Garcia MA, Wraige E, Bodi I, Deshpande C, Özdemir Ö, Daimagüler HS, Pfuhl M, Holt M, Brandmeier B, Grover S, Fluss J, Longman C, Farrugia ME, Matthews E, Hanna M, Muntoni F, Sarkozy A, Phadke R, Quinlivan R, Oates EC, Schröder R, Thiel C, Reimann J, Voermans N, Erasmus C, Kamsteeg EJ, Konersman C, Grosmann C, McKee S, Tirupathi S, Moore SA, Wilichowski E, Hobbiebrunken E, Dekomien G, Richard I, Van den Bergh P, Domínguez-González C, Cirak S, Ferreiro A, Jungbluth H, Gautel M. Making sense of missense variants in TTN-related congenital myopathies. Acta Neuropathol 2021; 141:431-453. [PMID: 33449170 PMCID: PMC7882473 DOI: 10.1007/s00401-020-02257-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 12/20/2020] [Accepted: 12/20/2020] [Indexed: 12/15/2022]
Abstract
Mutations in the sarcomeric protein titin, encoded by TTN, are emerging as a common cause of myopathies. The diagnosis of a TTN-related myopathy is, however, often not straightforward due to clinico-pathological overlap with other myopathies and the prevalence of TTN variants in control populations. Here, we present a combined clinico-pathological, genetic and biophysical approach to the diagnosis of TTN-related myopathies and the pathogenicity ascertainment of TTN missense variants. We identified 30 patients with a primary TTN-related congenital myopathy (CM) and two truncating variants, or one truncating and one missense TTN variant, or homozygous for one TTN missense variant. We found that TTN-related myopathies show considerable overlap with other myopathies but are strongly suggested by a combination of certain clinico-pathological features. Presentation was typically at birth with the clinical course characterized by variable progression of weakness, contractures, scoliosis and respiratory symptoms but sparing of extraocular muscles. Cardiac involvement depended on the variant position. Our biophysical analyses demonstrated that missense mutations associated with CMs are strongly destabilizing and exert their effect when expressed on a truncating background or in homozygosity. We hypothesise that destabilizing TTN missense mutations phenocopy truncating variants and are a key pathogenic feature of recessive titinopathies that might be amenable to therapeutic intervention.
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Affiliation(s)
- Martin Rees
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Roksana Nikoopour
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Atsushi Fukuzawa
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Miguel A Fernandez-Garcia
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK
| | - Elizabeth Wraige
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK
| | - Istvan Bodi
- Department of Clinical Neuropathology, King's College Hospital, London, UK
| | | | - Özkan Özdemir
- Centre for Molecular Medicine, University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Hülya-Sevcan Daimagüler
- Centre for Molecular Medicine, University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Mark Pfuhl
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
- School of Cardiovascular Medicine and Sciences, King's College London BHF Centre of Research Excellence, London, UK
| | - Mark Holt
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
- School of Cardiovascular Medicine and Sciences, King's College London BHF Centre of Research Excellence, London, UK
| | - Birgit Brandmeier
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Sarah Grover
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Joël Fluss
- Pediatric Neurology Unit, Paediatrics Subspecialties Service, Geneva Children's Hospital, Geneva, Switzerland
| | - Cheryl Longman
- West of Scotland Regional Genetics Service, Laboratory Medicine Building, Queen Elizabeth University Hospital, Glasgow, UK
| | | | - Emma Matthews
- MRC Neuromuscular Centre, National Hospital for Neurology and Neurosurgery, Queen's Square, London, UK
| | - Michael Hanna
- MRC Neuromuscular Centre, National Hospital for Neurology and Neurosurgery, Queen's Square, London, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Institute of Child Health, University College London, Great Ormond Street Hospital Trust, London, UK
| | - Anna Sarkozy
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
| | - Rahul Phadke
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
| | - Ros Quinlivan
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
| | - Emily C Oates
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sidney, Australia
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Rolf Schröder
- Institute of Neuropathology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Christian Thiel
- Department of Genetics, University of Erlangen, Erlangen, Germany
| | - Jens Reimann
- Muscle Laboratory, Department of Neurology, University of Bonn Medical Centre, Bonn, Germany
| | - Nicol Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Corrie Erasmus
- Department of Paediatric Neurology, Radboud University, Nijmegen, The Netherlands
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chaminda Konersman
- UCSD, Rady Children's Hospital, and VA San Diego Healthcare System, San Diego, USA
| | | | - Shane McKee
- Northern Ireland Regional Genetics Service, Belfast City Hospital, Belfast, UK
| | - Sandya Tirupathi
- Department of Paediatric Neurology, Royal Belfast Hospital for Sick Children, Belfast, UK
| | - Steven A Moore
- Department of Pathology, The University of Iowa, Iowa City, IA, USA
| | | | - Elke Hobbiebrunken
- Department of Paediatric Neurology, University of Göttingen, Göttingen, Germany
| | | | - Isabelle Richard
- Genethon and UMR_S951, INSERM, Université Evry, Université Paris Saclay, Evry, 91002, Evry, France
| | - Peter Van den Bergh
- Neuromuscular Reference Centre, Department of Neurology, University Hospital Saint-Luc, Brussels, Belgium
| | | | - Sebahattin Cirak
- Centre for Molecular Medicine, University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
- Centre for Rare Diseases (ZSEK), University of Cologne, Cologne, Germany
| | - Ana Ferreiro
- Basic and Translational Myology Laboratory, Université de Paris, Paris, France
- Centre de Référence Des Maladies Neuromusculaires, APHP, Institut of Myology, GHU Pitié Salpêtrière- Charles Foix, Paris, France
| | - Heinz Jungbluth
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK
- Department of Clinical and Basic Neuroscience, IoPPN, King's College London, London, UK
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK.
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21
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Sponga A, Arolas JL, Schwarz TC, Jeffries CM, Kostan J, Polyansky AA, Zagrovic B, Svergun D, Warscheid B, Konrat R, Gautel M, Djinovic-Carugo K. Sarcomeric Protein Fatz Forms a Tight Fuzzy Complex with α-Actinin and Phase-Separates in Vitro. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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22
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Parijat P, Kondacs L, Alexandrovich A, Gautel M, Cobb AJA, Kampourakis T. High Throughput Screen Identifies Small Molecule Effectors That Modulate Thin Filament Activation in Cardiac Muscle. ACS Chem Biol 2021; 16:225-235. [PMID: 33315370 DOI: 10.1021/acschembio.0c00908] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Current therapeutic interventions for both heart disease and heart failure are largely insufficient and associated with undesired side effects. Biomedical research has emphasized the role of sarcomeric protein function for the normal performance and energy efficiency of the heart, suggesting that directly targeting the contractile myofilaments themselves using small molecule effectors has therapeutic potential and will likely result in greater drug efficacy and selectivity. In this study, we developed a robust and highly reproducible fluorescence polarization-based high throughput screening (HTS) assay that directly targets the calcium-dependent interaction between cardiac troponin C (cTnC) and the switch region of cardiac troponin I (cTnISP), with the aim of identifying small molecule effectors of the cardiac thin filament activation pathway. We screened a commercially available small molecule library and identified several hit compounds with both inhibitory and activating effects. We used a range of biophysical and biochemical methods to characterize hit compounds and identified fingolimod, a sphingosin-1-phosphate receptor modulator, as a new troponin-based small molecule effector. Fingolimod decreased the ATPase activity and calcium sensitivity of demembranated cardiac muscle fibers in a dose-dependent manner, suggesting that the compound acts as a calcium desensitizer. We investigated fingolimod's mechanism of action using a combination of computational studies, biophysical methods, and synthetic chemistry, showing that fingolimod bound to cTnC repels cTnISP via mainly electrostatic repulsion of its positively charged tail. These results suggest that fingolimod is a potential new lead compound/scaffold for the development of troponin-directed heart failure therapeutics.
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Affiliation(s)
- Priyanka Parijat
- Randall Centre for Cell and Molecular Biophysics, King’s College London, and British Heart Foundation Centre of Research Excellence, London SE1 1UL, United Kingdom
| | - Laszlo Kondacs
- Department of Chemistry, King’s College London, 7 Trinity Street, London, SE1 1DB, United Kingdom
| | - Alexander Alexandrovich
- Randall Centre for Cell and Molecular Biophysics, King’s College London, and British Heart Foundation Centre of Research Excellence, London SE1 1UL, United Kingdom
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King’s College London, and British Heart Foundation Centre of Research Excellence, London SE1 1UL, United Kingdom
| | - Alexander J. A. Cobb
- Department of Chemistry, King’s College London, 7 Trinity Street, London, SE1 1DB, United Kingdom
| | - Thomas Kampourakis
- Randall Centre for Cell and Molecular Biophysics, King’s College London, and British Heart Foundation Centre of Research Excellence, London SE1 1UL, United Kingdom
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Fukuzawa A, Koch D, Grover S, Rees M, Gautel M. When is an obscurin variant pathogenic? The impact of Arg4344Gln and Arg4444Trp variants on protein-protein interactions and protein stability. Hum Mol Genet 2021; 30:1131-1141. [PMID: 33438037 PMCID: PMC8188405 DOI: 10.1093/hmg/ddab010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/17/2020] [Accepted: 01/04/2021] [Indexed: 11/13/2022] Open
Abstract
Obscurin is a giant muscle protein that connects the sarcomere with the sarcoplasmic reticulum, and has poorly understood structural and signalling functions. Increasingly, obscurin variants are implicated in the pathophysiology of cardiovascular diseases. The Arg4344Gln variant (R4344Q) in obscurin domain Ig58, initially discovered in a patient with hypertrophic cardiomyopathy, has been reported to reduce binding to titin domains Z8-Z9, impairing obscurin’s Z-disc localization. An R4344Q knock-in mouse developed a cardiomyopathy-like phenotype with abnormal Ca2+-handling and arrhythmias, which were attributed to an enhanced affinity of a putative interaction between obscurin Ig58 and phospholamban (PLN) due to the R4344Q variant. However, the R4344Q variant is found in 15% of African Americans, arguing against its pathogenicity. To resolve this apparent paradox, we quantified the influence of the R4344Q variant (alongside another potentially pathogenic variant: Arg4444Trp (R4444W)) on binding to titin Z8-Z9, novex-3 and PLN using pull-down assays and microscale thermophoresis and characterized the influence on domain stability using differential scanning fluorimetry. We found no changes in titin binding and thermostability for both variants and modestly increased affinities of PLN for R4344Q and R4444W. While we could not confirm the novex-3/obscurin interaction, the PLN/obscurin interaction relies on the transmembrane region of PLN and is not reproducible in mammalian cells, suggesting it is an in vitro artefact. Without clear clinical evidence for disease involvement, we advise against classifying these obscurin variants as pathogenic.
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Affiliation(s)
- Atsushi Fukuzawa
- Randall Centre for Cell & Molecular Biophysics, King's College London, 18-20 Newcomen Street, SE1 1UL, UK
| | - Daniel Koch
- Randall Centre for Cell & Molecular Biophysics, King's College London, 18-20 Newcomen Street, SE1 1UL, UK
| | - Sarah Grover
- Randall Centre for Cell & Molecular Biophysics, King's College London, 18-20 Newcomen Street, SE1 1UL, UK
| | - Martin Rees
- Randall Centre for Cell & Molecular Biophysics, King's College London, 18-20 Newcomen Street, SE1 1UL, UK
| | - Mathias Gautel
- Randall Centre for Cell & Molecular Biophysics, King's College London, 18-20 Newcomen Street, SE1 1UL, UK
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24
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Lewis HR, Eminaga S, Gautel M, Avkiran M. Phosphorylation at Serines 157 and 161 Is Necessary for Preserving Cardiac Expression Level and Functions of Sarcomeric Z-Disc Protein Telethonin. Front Physiol 2021; 12:732020. [PMID: 34566695 PMCID: PMC8455888 DOI: 10.3389/fphys.2021.732020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/16/2021] [Indexed: 11/13/2022] Open
Abstract
Aims: In cardiac myocytes, the sarcomeric Z-disc protein telethonin is constitutively bis-phosphorylated at C-terminal residues S157 and S161; however, the functional significance of this phosphorylation is not known. We sought to assess the significance of telethonin phosphorylation in vivo, using a novel knock-in (KI) mouse model generated to express non-phosphorylatable telethonin (Tcap S157/161A). Methods and Results: Tcap S157/161A and wild-type (WT) littermates were characterized by echocardiography at baseline and after sustained β-adrenergic stimulation via isoprenaline infusion. Heart tissues were collected for gravimetric, biochemical, and histological analyses. At baseline, Tcap S157/161A mice did not show any variances in cardiac structure or function compared with WT littermates and mutant telethonin remained localized to the Z-disc. Ablation of telethonin phosphorylation sites resulted in a gene-dosage dependent decrease in the cardiac telethonin protein expression level in mice carrying the S157/161A alleles, without any alteration in telethonin mRNA levels. The proteasome inhibitor MG132 significantly increased the expression level of S157/161A telethonin protein in myocytes from Tcap S157/161A mice, but not telethonin protein in myocytes from WT mice, indicating a role for the ubiquitin-proteasome system in the regulation of telethonin protein expression level. Tcap S157/161A mice challenged with sustained β-adrenergic stimulation via isoprenaline infusion developed cardiac hypertrophy accompanied by mild systolic dysfunction. Furthermore, the telethonin protein expression level was significantly increased in WT mice following isoprenaline stimulation but this response was blunted in Tcap S157/161A mice. Conclusion: Overall, these data reveal that telethonin protein turnover in vivo is regulated in a novel phosphorylation-dependent manner and suggest that C-terminal phosphorylation may protect telethonin against proteasomal degradation and preserve cardiac function during hemodynamic stress. Given that human telethonin C-terminal mutations have been associated with cardiac and skeletal myopathies, further research on their potential impact on phosphorylation-dependent regulation of telethonin protein expression could provide valuable mechanistic insight into those myopathies.
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Affiliation(s)
- Hannah R. Lewis
- School of Cardiovascular Medicine and Sciences, St Thomas’ Hospital, King’s College London British Heart Foundation Centre of Research Excellence, London, United Kingdom
| | - Seda Eminaga
- School of Cardiovascular Medicine and Sciences, St Thomas’ Hospital, King’s College London British Heart Foundation Centre of Research Excellence, London, United Kingdom
| | - Mathias Gautel
- School of Basic and Medical Biosciences, Guy’s Hospital, King’s College London British Heart Foundation Centre of Research Excellence, London, United Kingdom
| | - Metin Avkiran
- School of Cardiovascular Medicine and Sciences, St Thomas’ Hospital, King’s College London British Heart Foundation Centre of Research Excellence, London, United Kingdom
- *Correspondence: Metin Avkiran,
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Bennett P, Rees M, Gautel M. The Axial Alignment of Titin on the Muscle Thick Filament Supports Its Role as a Molecular Ruler. J Mol Biol 2020; 432:4815-4829. [PMID: 32619437 PMCID: PMC7427331 DOI: 10.1016/j.jmb.2020.06.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 01/04/2023]
Abstract
The giant protein titin is expressed in vertebrate striated muscle where it spans half a sarcomere from the Z-disc to the M-band and is essential for muscle organisation, activity and health. The C-terminal portion of titin is closely associated with the thick, myosin-containing filament and exhibits a complex pattern of immunoglobulin and fibronectin domains. This pattern reflects features of the filament organisation suggesting that it acts as a molecular ruler and template, but the exact axial disposition of the molecule has not been determined. Here, we present data that allow us to precisely locate titin domains axially along the thick filament from its tip to the edge of the bare zone. We find that the domains are regularly distributed along the filament at 4-nm intervals and we can determine the domains that associate with features of the filament, such as the 11 stripes of accessory proteins. We confirm that the nine stripes ascribed to myosin binding protein-C are not related to the titin sequence previously assumed; rather, they relate to positions approximately 18 domains further towards the C terminus along titin. This disposition also allows a subgroup of titin domains comprising two or three fibronectin domains to associate with each of the 49 levels of myosin heads in each half filament. The results strongly support the role of titin as a blueprint for the thick filament and the arrangement of the myosin motor domains.
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Affiliation(s)
- Pauline Bennett
- The Randall Centre for Cell & Molecular Biophysics, School of Basic and Medical Biosciences, New Hunt's House, Guy's Campus, King's College London, London, UK.
| | - Martin Rees
- The Randall Centre for Cell & Molecular Biophysics, School of Basic and Medical Biosciences, New Hunt's House, Guy's Campus, King's College London, London, UK.
| | - Mathias Gautel
- The Randall Centre for Cell & Molecular Biophysics, School of Basic and Medical Biosciences, New Hunt's House, Guy's Campus, King's College London, London, UK.
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Sevrieva IR, Brandmeier B, Ponnam S, Gautel M, Irving M, Campbell KS, Sun YB, Kampourakis T. Cardiac myosin regulatory light chain kinase modulates cardiac contractility by phosphorylating both myosin regulatory light chain and troponin I. J Biol Chem 2020; 295:4398-4410. [PMID: 32086378 PMCID: PMC7135997 DOI: 10.1074/jbc.ra119.011945] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/14/2020] [Indexed: 12/14/2022] Open
Abstract
Heart muscle contractility and performance are controlled by posttranslational modifications of sarcomeric proteins. Although myosin regulatory light chain (RLC) phosphorylation has been studied extensively in vitro and in vivo, the precise role of cardiac myosin light chain kinase (cMLCK), the primary kinase acting upon RLC, in the regulation of cardiomyocyte contractility remains poorly understood. In this study, using recombinantly expressed and purified proteins, various analytical methods, in vitro and in situ kinase assays, and mechanical measurements in isolated ventricular trabeculae, we demonstrate that human cMLCK is not a dedicated kinase for RLC but can phosphorylate other sarcomeric proteins with well-characterized regulatory functions. We show that cMLCK specifically monophosphorylates Ser23 of human cardiac troponin I (cTnI) in isolation and in the trimeric troponin complex in vitro and in situ in the native environment of the muscle myofilament lattice. Moreover, we observed that human cMLCK phosphorylates rodent cTnI to a much smaller extent in vitro and in situ, suggesting species-specific adaptation of cMLCK. Although cMLCK treatment of ventricular trabeculae exchanged with rat or human troponin increased their cross-bridge kinetics, the increase in sensitivity of myofilaments to calcium was significantly blunted by human TnI, suggesting that human cTnI phosphorylation by cMLCK modifies the functional consequences of RLC phosphorylation. We propose that cMLCK-mediated phosphorylation of TnI is functionally significant and represents a critical signaling pathway that coordinates the regulatory states of thick and thin filaments in both physiological and potentially pathophysiological conditions of the heart.
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Affiliation(s)
- Ivanka R Sevrieva
- Randall Centre for Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, King's College London, London SE1 1UL, United Kingdom
| | - Birgit Brandmeier
- Randall Centre for Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, King's College London, London SE1 1UL, United Kingdom
| | - Saraswathi Ponnam
- Randall Centre for Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, King's College London, London SE1 1UL, United Kingdom
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, King's College London, London SE1 1UL, United Kingdom
| | - Malcolm Irving
- Randall Centre for Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, King's College London, London SE1 1UL, United Kingdom
| | - Kenneth S Campbell
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0298
| | - Yin-Biao Sun
- Randall Centre for Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, King's College London, London SE1 1UL, United Kingdom
| | - Thomas Kampourakis
- Randall Centre for Cell and Molecular Biophysics and British Heart Foundation Centre of Research Excellence, King's College London, London SE1 1UL, United Kingdom
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27
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Sarkozy A, Fernandez-Garcia M, Manzur A, Mein R, Bodi I, Phadke R, Wraige E, Deshpande C, Holder S, Hurst J, Gautel M, Jungbluth H, Muntoni F. P.109Congenital myopathy in patients with Kabuki and Au-Kline syndromes - Double trouble or expansion of the phenotypes? Neuromuscul Disord 2019. [DOI: 10.1016/j.nmd.2019.06.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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28
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Phadke R, Sarkozy A, Oates E, Mein R, Bodi I, Feng L, Manzur A, Thomas N, Illingworth M, Mazanti I, Ellard S, Sewry C, Gautel M, Jungbluth H, Muntoni F. P.236Myofibres with subsarcolemmal rims and/or central aggregates of mitochondria (SRCAM) are prevalent in congenital titinopathies. Neuromuscul Disord 2019. [DOI: 10.1016/j.nmd.2019.06.350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Lopez Arolas J, Sponga A, Smith L, Gautel M, Djinovic-Carugo K. Structural basis of α-actinin-2/titin interaction in the Z-disk. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s2053273319094142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Nikoopour R, Rees M, Pfuhl M, Ferreiro A, Elliott P, Gautel M. Structural and biophysical characterisation of titin missense variants in genetic myopathies and cardiomyopathies. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s2053273318088812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Marsh RJ, Pfisterer K, Bennett P, Hirvonen LM, Gautel M, Jones GE, Cox S. Artifact-free high-density localization microscopy analysis. Nat Methods 2018; 15:689-692. [DOI: 10.1038/s41592-018-0072-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 06/08/2018] [Indexed: 11/09/2022]
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Laddach A, Gautel M, Fraternali F. TITINdb-a computational tool to assess titin's role as a disease gene. Bioinformatics 2017; 33:3482-3485. [PMID: 29077808 PMCID: PMC5860166 DOI: 10.1093/bioinformatics/btx424] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/15/2017] [Accepted: 07/03/2017] [Indexed: 01/22/2023] Open
Abstract
SUMMARY Large numbers of rare and unique titin missense variants have been discovered in both healthy and disease cohorts, thus the correct classification of variants as pathogenic or non-pathogenic has become imperative. Due to titin's large size (363 coding exons), current web applications are unable to map titin variants to domain structures. Here, we present a web application, TITINdb, which integrates titin structure, variant, sequence and isoform information, along with pre-computed predictions of the impact of non-synonymous single nucleotide variants, to facilitate the correct classification of titin variants. AVAILABILITY AND IMPLEMENTATION TITINdb can be freely accessed at http://fraternalilab.kcl.ac.uk/TITINdb. CONTACT franca.fraternali@kcl.ac.uk. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Anna Laddach
- Randall Division of Cell and Molecular Biophysics, King’s College London BHF Centre of Research Excellence, London, UK
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics, King’s College London BHF Centre of Research Excellence, London, UK
| | - Franca Fraternali
- Randall Division of Cell and Molecular Biophysics, King’s College London BHF Centre of Research Excellence, London, UK
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Hackman P, Savarese M, Bönneman C, Ferreiro A, Beggs A, Gautel M, Davis M, Evangelista T, Glumac JN, Laporte J, Smith J, Richard I, Granzier H, Schneider R, Jungbluth H, Foye S, Frase AR, Udd B. Establishment of an international database of Titin mutations and their phenotypes – a follow up. Neuromuscul Disord 2017. [DOI: 10.1016/j.nmd.2017.06.519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Touraine R, Laquerrière A, Petcu CA, Marguet F, Byrne S, Mein R, Yau S, Mohammed S, Guibaud L, Gautel M, Jungbluth H. Autopsy findings in EPG5-related Vici syndrome with antenatal onset. Am J Med Genet A 2017; 173:2522-2527. [PMID: 28748650 DOI: 10.1002/ajmg.a.38342] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/18/2017] [Accepted: 06/06/2017] [Indexed: 11/11/2022]
Abstract
Vici syndrome is one of the most extensive inherited human multisystem disorders and due to recessive mutations in EPG5 encoding a key autophagy regulator with a crucial role in autophagosome-lysosome fusion. The condition presents usually early in life, with features of severe global developmental delay, profound failure to thrive, (acquired) microcephaly, callosal agenesis, cataracts, cardiomyopathy, hypopigmentation, and combined immunodeficiency. Clinical course is variable but usually progressive and associated with high mortality. Here, we present a fetus, offspring of consanguineous parents, in whom callosal agenesis and other developmental brain abnormalities were detected on fetal ultrasound scan (US) and subsequent MRI scan in the second trimester. Postmortem examination performed after medically indicated termination of pregnancy confirmed CNS abnormalities and provided additional evidence for skin hypopigmentation, nascent cataracts, and hypertrophic cardiomyopathy. Genetic testing prompted by a suggestive combination of features revealed a homozygous EPG5 mutation (c.5870-1G>A) predicted to cause aberrant splicing of the EPG5 transcript. Our findings expand the phenotypical spectrum of EPG5-related Vici syndrome and suggest that this severe condition may already present in utero. While callosal agenesis is not an uncommon finding in fetal medicine, additional presence of hypopigmentation, cataracts and cardiomyopathy is rare and should prompt EPG5 testing.
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Affiliation(s)
- Renaud Touraine
- CHU-Hôpital Nord, Service de Génétique, Saint Etienne, France
| | - Annie Laquerrière
- Pathology Laboratory, Rouen University Hospital, Rouen, France
- Normandie Univ, UNIROUEN, NéoVasc, Rouen, France
| | | | - Florent Marguet
- Pathology Laboratory, Rouen University Hospital, Rouen, France
- Normandie Univ, UNIROUEN, NéoVasc, Rouen, France
| | - Susan Byrne
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | | | - Shu Yau
- GSTS Pathology, Guy's Hospital, London, UK
| | | | - Laurent Guibaud
- Imagerie Pédiatrique et Fœtale, Hôpital Femme Mère Enfant, Lyon-Bron, France
| | - Mathias Gautel
- Randall Division for Cell and Molecular Biophysics, Muscle Signaling Section, King's College, London, UK
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
- Randall Division for Cell and Molecular Biophysics, Muscle Signaling Section, King's College, London, UK
- Department of Basic and Clinical Neuroscience, IoPPN, King's College London, London, UK
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Baumann F, Bauer MS, Rees M, Alexandrovich A, Gautel M, Pippig DA, Gaub HE. Increasing evidence of mechanical force as a functional regulator in smooth muscle myosin light chain kinase. eLife 2017; 6. [PMID: 28696205 PMCID: PMC5505704 DOI: 10.7554/elife.26473] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/20/2017] [Indexed: 11/18/2022] Open
Abstract
Mechanosensitive proteins are key players in cytoskeletal remodeling, muscle contraction, cell migration and differentiation processes. Smooth muscle myosin light chain kinase (smMLCK) is a member of a diverse group of serine/threonine kinases that feature cytoskeletal association. Its catalytic activity is triggered by a conformational change upon Ca2+/calmodulin (Ca2+/CaM) binding. Due to its significant homology with the force-activated titin kinase, smMLCK is suspected to be also regulatable by mechanical stress. In this study, a CaM-independent activation mechanism for smMLCK by mechanical release of the inhibitory elements is investigated via high throughput AFM single-molecule force spectroscopy. The characteristic pattern of transitions between different smMLCK states and their variations in the presence of different substrates and ligands are presented. Interaction between kinase domain and regulatory light chain (RLC) substrate is identified in the absence of CaM, indicating restored substrate-binding capability due to mechanically induced removal of the auto-inhibitory regulatory region. DOI:http://dx.doi.org/10.7554/eLife.26473.001
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Affiliation(s)
- Fabian Baumann
- Chair for Applied Physics and Center for Nanoscience, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Magnus Sebastian Bauer
- Chair for Applied Physics and Center for Nanoscience, Ludwig-Maximilians-Universität München, Munich, Germany.,Center for Integrated Protein Science Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin Rees
- Randall Division of Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, London, United Kingdom
| | - Alexander Alexandrovich
- Randall Division of Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, London, United Kingdom
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, London, United Kingdom
| | - Diana Angela Pippig
- Chair for Applied Physics and Center for Nanoscience, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Hermann Eduard Gaub
- Chair for Applied Physics and Center for Nanoscience, Ludwig-Maximilians-Universität München, Munich, Germany
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Rees M, Fraternali F, Elliott P, Gautel M. Structural and Biophysical Analysis of Hypertrophic Cardiomyopathy-Linked Titin Missense Variants. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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37
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Pernigo S, Fukuzawa A, Beedle AEM, Holt M, Round A, Pandini A, Garcia-Manyes S, Gautel M, Steiner RA. Binding of Myomesin to Obscurin-Like-1 at the Muscle M-Band Provides a Strategy for Isoform-Specific Mechanical Protection. Structure 2016; 25:107-120. [PMID: 27989621 PMCID: PMC5222588 DOI: 10.1016/j.str.2016.11.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/16/2016] [Accepted: 11/18/2016] [Indexed: 12/03/2022]
Abstract
The sarcomeric cytoskeleton is a network of modular proteins that integrate mechanical and signaling roles. Obscurin, or its homolog obscurin-like-1, bridges the giant ruler titin and the myosin crosslinker myomesin at the M-band. Yet, the molecular mechanisms underlying the physical obscurin(-like-1):myomesin connection, important for mechanical integrity of the M-band, remained elusive. Here, using a combination of structural, cellular, and single-molecule force spectroscopy techniques, we decode the architectural and functional determinants defining the obscurin(-like-1):myomesin complex. The crystal structure reveals a trans-complementation mechanism whereby an incomplete immunoglobulin-like domain assimilates an isoform-specific myomesin interdomain sequence. Crucially, this unconventional architecture provides mechanical stability up to forces of ∼135 pN. A cellular competition assay in neonatal rat cardiomyocytes validates the complex and provides the rationale for the isoform specificity of the interaction. Altogether, our results reveal a novel binding strategy in sarcomere assembly, which might have implications on muscle nanomechanics and overall M-band organization. The structure of the human obscurin-like-1:myomesin complex has been determined A myomesin sequence complements an immunoglobulin fold of obscurin-like-1 This binding mechanism provides mechanical stability up to forces of ∼135 pN Possible implications on muscle nanomechanics and M-band organization are discussed
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Affiliation(s)
- Stefano Pernigo
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Atsushi Fukuzawa
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Cardiovascular Division, King's College London BHF Centre of Research Excellence, London SE1 1UL, UK
| | - Amy E M Beedle
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Department of Physics, King's College London, London WC2R 2LS, UK
| | - Mark Holt
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Cardiovascular Division, King's College London BHF Centre of Research Excellence, London SE1 1UL, UK
| | - Adam Round
- European Molecular Biology Laboratory, Grenoble Outstation, 38042 Grenoble, France; School of Chemical and Physical Sciences, Keele University, Keele, Staffordshire, UK
| | - Alessandro Pandini
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Department of Computer Science and Synthetic Biology Theme, Brunel University London, London UB8 3PH, UK
| | - Sergi Garcia-Manyes
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Department of Physics, King's College London, London WC2R 2LS, UK.
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Cardiovascular Division, King's College London BHF Centre of Research Excellence, London SE1 1UL, UK.
| | - Roberto A Steiner
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK.
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Abstract
Highly ordered organisation of striated muscle is the prerequisite for the fast and unidirectional development of force and motion during heart and skeletal muscle contraction. A group of proteins, summarised as the sarcomeric cytoskeleton, is essential for the ordered assembly of actin and myosin filaments into sarcomeres, by combining architectural, mechanical and signalling functions. This review discusses recent cell biological, biophysical and structural insight into the regulated assembly of sarcomeric cytoskeleton proteins and their roles in dissipating mechanical forces in order to maintain sarcomere integrity during passive extension and active contraction. α-Actinin crosslinks in the Z-disk show a pivot-and-rod structure that anchors both titin and actin filaments. In contrast, the myosin crosslinks formed by myomesin in the M-band are of a ball-and-spring type and may be crucial in providing stable yet elastic connections during active contractions, especially eccentric exercise.
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Affiliation(s)
- Mathias Gautel
- King's College London BHF Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics, and Cardiovascular Division, New Hunt's House, London SE1 1UL, UK
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, Vienna A-1030, Austria Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, Ljubljana 1000, Slovenia
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Gautel M, Rees M, Nikoopour R, Fukuzawa A, Fraternali F, Laddach A, Pernigo S, Holt M, Steiner R. Sarcomeric signalling proteins: Hubs for mechanosensation and hotspots for inherited myopathies. Neuromuscul Disord 2016. [DOI: 10.1016/j.nmd.2016.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Hastings R, de Villiers CP, Hooper C, Ormondroyd L, Pagnamenta A, Lise S, Salatino S, Knight SJL, Taylor JC, Thomson KL, Arnold L, Chatziefthimiou SD, Konarev PV, Wilmanns M, Ehler E, Ghisleni A, Gautel M, Blair E, Watkins H, Gehmlich K. Combination of Whole Genome Sequencing, Linkage, and Functional Studies Implicates a Missense Mutation in Titin as a Cause of Autosomal Dominant Cardiomyopathy With Features of Left Ventricular Noncompaction. ACTA ACUST UNITED AC 2016; 9:426-435. [PMID: 27625337 PMCID: PMC5068189 DOI: 10.1161/circgenetics.116.001431] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 08/31/2016] [Indexed: 11/16/2022]
Abstract
Supplemental Digital Content is available in the text. Background— High throughput next-generation sequencing techniques have made whole genome sequencing accessible in clinical practice; however, the abundance of variation in the human genomes makes the identification of a disease-causing mutation on a background of benign rare variants challenging. Methods and Results— Here we combine whole genome sequencing with linkage analysis in a 3-generation family affected by cardiomyopathy with features of autosomal dominant left ventricular noncompaction cardiomyopathy. A missense mutation in the giant protein titin is the only plausible disease-causing variant that segregates with disease among the 7 surviving affected individuals, with interrogation of the entire genome excluding other potential causes. This A178D missense mutation, affecting a conserved residue in the second immunoglobulin-like domain of titin, was introduced in a bacterially expressed recombinant protein fragment and biophysically characterized in comparison to its wild-type counterpart. Multiple experiments, including size exclusion chromatography, small-angle x ray scattering, and circular dichroism spectroscopy suggest partial unfolding and domain destabilization in the presence of the mutation. Moreover, binding experiments in mammalian cells show that the mutation markedly impairs binding to the titin ligand telethonin. Conclusions— Here we present genetic and functional evidence implicating the novel A178D missense mutation in titin as the cause of a highly penetrant familial cardiomyopathy with features of left ventricular noncompaction. This expands the spectrum of titin’s roles in cardiomyopathies. It furthermore highlights that rare titin missense variants, currently often ignored or left uninterpreted, should be considered to be relevant for cardiomyopathies and can be identified by the approach presented here.
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Jungbluth H, Ochala J, Treves S, Gautel M. Current and future therapeutic approaches to the congenital myopathies. Semin Cell Dev Biol 2016; 64:191-200. [PMID: 27515125 DOI: 10.1016/j.semcdb.2016.08.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 08/04/2016] [Accepted: 08/08/2016] [Indexed: 12/14/2022]
Abstract
The congenital myopathies - including Central Core Disease (CCD), Multi-minicore Disease (MmD), Centronuclear Myopathy (CNM), Nemaline Myopathy (NM) and Congenital Fibre Type Disproportion (CFTD) - are a genetically heterogeneous group of early-onset neuromuscular conditions characterized by distinct histopathological features, and associated with a substantial individual and societal disease burden. Appropriate supportive management has substantially improved patient morbidity and mortality but there is currently no cure. Recent years have seen an exponential increase in the genetic and molecular understanding of these conditions, leading to the identification of underlying defects in proteins involved in calcium homeostasis and excitation-contraction coupling, thick/thin filament assembly and function, redox regulation, membrane trafficking and/or autophagic pathways. Based on these findings, specific therapies are currently being developed, or are already approaching the clinical trial stage. Despite undeniable progress, therapy development faces considerable challenges, considering the rarity and diversity of specific conditions, and the size and complexity of some of the genes and proteins involved. The present review will summarize the key genetic, histopathological and clinical features of specific congenital myopathies, and outline therapies already available or currently being developed in the context of known pathogenic mechanisms. The relevance of newly discovered molecular mechanisms and novel gene editing strategies for future therapy development will be discussed.
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Affiliation(s)
- Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, United Kingdom; Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section Biophysics and Cardiovascular Division, King's College BHF Centre of Research Excellence, United Kingdom; Department of Basic and Clinical Neuroscience, IoPPN, King's College, London, United Kingdom.
| | - Julien Ochala
- Centre of Human and Aerospace Physiological Sciences, King's College London, United Kingdom
| | - Susan Treves
- Departments of Biomedicine and Anaesthesia, Basel University Hospital, 4031 Basel, Switzerland
| | - Mathias Gautel
- Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section Biophysics and Cardiovascular Division, King's College BHF Centre of Research Excellence, United Kingdom
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Byrne S, Cullup T, Fanto M, Gautel M, Jungbluth H. Reply: Aberrant splicing induced by the most commonEPG5mutation in an individual with Vici syndrome. Brain 2016; 139:e53. [DOI: 10.1093/brain/aww136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Byrne S, Jansen L, U-King-Im JM, Siddiqui A, Lidov HGW, Bodi I, Smith L, Mein R, Cullup T, Dionisi-Vici C, Al-Gazali L, Al-Owain M, Bruwer Z, Al Thihli K, El-Garhy R, Flanigan KM, Manickam K, Zmuda E, Banks W, Gershoni-Baruch R, Mandel H, Dagan E, Raas-Rothschild A, Barash H, Filloux F, Creel D, Harris M, Hamosh A, Kölker S, Ebrahimi-Fakhari D, Hoffmann GF, Manchester D, Boyer PJ, Manzur AY, Lourenco CM, Pilz DT, Kamath A, Prabhakar P, Rao VK, Rogers RC, Ryan MM, Brown NJ, McLean CA, Said E, Schara U, Stein A, Sewry C, Travan L, Wijburg FA, Zenker M, Mohammed S, Fanto M, Gautel M, Jungbluth H. EPG5-related Vici syndrome: a paradigm of neurodevelopmental disorders with defective autophagy. Brain 2016; 139:765-81. [PMID: 26917586 PMCID: PMC4766378 DOI: 10.1093/brain/awv393] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/31/2015] [Accepted: 11/12/2015] [Indexed: 01/07/2023] Open
Abstract
Vici syndrome is a progressive neurodevelopmental multisystem disorder due to recessive mutations in the key autophagy gene EPG5. We report genetic, clinical, neuroradiological, and neuropathological features of 50 children from 30 families, as well as the neuronal phenotype of EPG5 knock-down in Drosophila melanogaster. We identified 39 different EPG5 mutations, most of them truncating and predicted to result in reduced EPG5 protein. Most mutations were private, but three recurrent mutations (p.Met2242Cysfs*5, p.Arg417*, and p.Gln336Arg) indicated possible founder effects. Presentation was mainly neonatal, with marked hypotonia and feeding difficulties. In addition to the five principal features (callosal agenesis, cataracts, hypopigmentation, cardiomyopathy, and immune dysfunction), we identified three equally consistent features (profound developmental delay, progressive microcephaly, and failure to thrive). The manifestation of all eight of these features has a specificity of 97%, and a sensitivity of 89% for the presence of an EPG5 mutation and will allow informed decisions about genetic testing. Clinical progression was relentless and many children died in infancy. Survival analysis demonstrated a median survival time of 24 months (95% confidence interval 0-49 months), with only a 10th of patients surviving to 5 years of age. Survival outcomes were significantly better in patients with compound heterozygous mutations (P = 0.046), as well as in patients with the recurrent p.Gln336Arg mutation. Acquired microcephaly and regression of skills in long-term survivors suggests a neurodegenerative component superimposed on the principal neurodevelopmental defect. Two-thirds of patients had a severe seizure disorder, placing EPG5 within the rapidly expanding group of genes associated with early-onset epileptic encephalopathies. Consistent neuroradiological features comprised structural abnormalities, in particular callosal agenesis and pontine hypoplasia, delayed myelination and, less frequently, thalamic signal intensity changes evolving over time. Typical muscle biopsy features included fibre size variability, central/internal nuclei, abnormal glycogen storage, presence of autophagic vacuoles and secondary mitochondrial abnormalities. Nerve biopsy performed in one case revealed subtotal absence of myelinated axons. Post-mortem examinations in three patients confirmed neurodevelopmental and neurodegenerative features and multisystem involvement. Finally, downregulation of epg5 (CG14299) in Drosophila resulted in autophagic abnormalities and progressive neurodegeneration. We conclude that EPG5-related Vici syndrome defines a novel group of neurodevelopmental disorders that should be considered in patients with suggestive features in whom mitochondrial, glycogen, or lysosomal storage disorders have been excluded. Neurological progression over time indicates an intriguing link between neurodevelopment and neurodegeneration, also supported by neurodegenerative features in epg5-deficient Drosophila, and recent implication of other autophagy regulators in late-onset neurodegenerative disease.
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Affiliation(s)
- Susan Byrne
- 1 Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's and St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - Lara Jansen
- 2 Department of Basic and Clinical Neuroscience, IoPPN, King's College London, London, UK
| | - Jean-Marie U-King-Im
- 3 Department of Neuroradiology, Evelina's Children Hospital, Guy's and St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - Ata Siddiqui
- 3 Department of Neuroradiology, Evelina's Children Hospital, Guy's and St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - Hart G W Lidov
- 4 Department of Pathology, Boston Children's Hospital, Boston MA 02115, USA
| | - Istvan Bodi
- 5 Department of Clinical Neuropathology, King's College Hospital, London, UK
| | - Luke Smith
- 6 Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK
| | | | - Thomas Cullup
- 8 Regional Molecular Genetics Laboratory, Great Ormond Street Hospital, London, UK
| | - Carlo Dionisi-Vici
- 9 Division of Metabolism, Department of Paediatric Medicine, Bambino Gesù Children's Research Hospital, Rome
| | - Lihadh Al-Gazali
- 10 Departments of Paediatrics, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Mohammed Al-Owain
- 11 College of Medicine, Alfaisal University, Riyadh, Saudi Arabia 12 Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Zandre Bruwer
- 13 Genetic and Developmental Medicine Clinic, Sultan Qaboos University Hospital, Muscat, Sultanate of Oman
| | - Khalid Al Thihli
- 13 Genetic and Developmental Medicine Clinic, Sultan Qaboos University Hospital, Muscat, Sultanate of Oman
| | | | - Kevin M Flanigan
- 15 Center for Gene Therapy, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Kandamurugu Manickam
- 16 Center for Human and Molecular Genetics at The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Erik Zmuda
- 16 Center for Human and Molecular Genetics at The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Wesley Banks
- 16 Center for Human and Molecular Genetics at The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Ruth Gershoni-Baruch
- 17 Institute of Human Genetics, Rambam Health Care Campus and the Technion Faculty of Medicine, Haifa, Israel
| | - Hanna Mandel
- 18 Metabolic Disease Unit, Meyer Children's Hospital, Rambam Health Care Campus and the Technion Faculty of Medicine, Haifa, Israel
| | - Efrat Dagan
- 19 Department of Nursing, University of Haifa, Haifa, Israel
| | - Annick Raas-Rothschild
- 20 Institute of Rare Diseases, Institute of Genetics; Sheba Medical Centre, Tel Hashomer and the Sackler school of Medicine Tel Aviv University Ramat Aviv, Israel
| | - Hila Barash
- 20 Institute of Rare Diseases, Institute of Genetics; Sheba Medical Centre, Tel Hashomer and the Sackler school of Medicine Tel Aviv University Ramat Aviv, Israel
| | - Francis Filloux
- 21 Division of Pediatric Neurology, University of Utah School of Medicine and Primary Children's Medical Centre, Salt Lake City, Utah, USA
| | - Donnell Creel
- 22 University of Utah School of Medicine, Moran Eye Centre, Salt Lake City, Utah, USA
| | - Michael Harris
- 23 Innovation Center for Biomedical Informatics, Georgetown University Medical Center, Washington DC, USA
| | - Ada Hamosh
- 24 McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, USA
| | - Stefan Kölker
- 25 Division of Child Neurology and Metabolic Medicine, University Children's Hospital, Heidelberg, Germany
| | - Darius Ebrahimi-Fakhari
- 25 Division of Child Neurology and Metabolic Medicine, University Children's Hospital, Heidelberg, Germany
| | - Georg F Hoffmann
- 25 Division of Child Neurology and Metabolic Medicine, University Children's Hospital, Heidelberg, Germany
| | - David Manchester
- 26 Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, USA
| | - Philip J Boyer
- 27 Department of Pathology, East Carolina University, Brody School of Medicine, Brody Medical Sciences Building, Greenville, NC 27834, USA
| | | | | | - Daniela T Pilz
- 30 Institute of Medical Genetics, University Hospital of Wales, Cardiff, UK
| | - Arveen Kamath
- 30 Institute of Medical Genetics, University Hospital of Wales, Cardiff, UK
| | - Prab Prabhakar
- 31 Department of Paediatric Neurology, Great Ormond Street Children's Hospital, London, UK
| | - Vamshi K Rao
- 32 University of Nebraska Medical Center and Childrens Hospital and Medical Center, Omaha, Nebraska, USA
| | - R Curtis Rogers
- 33 Greenwood Genetic Center, Greenville, South Carolina, USA
| | - Monique M Ryan
- 34 Departments of Neurology, Royal Children's Hospital and Paediatrics, University of Melbourne, and Murdoch Childrens Research Institute, Melbourne Australia
| | - Natasha J Brown
- 35 Victorian Clinical Genetics Services, Murdoch Childrens Research Institute Parkville, Australia 36 Department of Paediatrics, University of Melbourne, Parkville, Australia 37 Department of Clinical Genetics, Austin Health, Australia
| | | | - Edith Said
- 39 Department of Anatomy and Cell Biology, University of Malta, Msida, Malta 40 Section of Medical Genetics, Mater dei Hospital, Msida, Malta
| | - Ulrike Schara
- 41 Pediatric Neurology, University Childrens Hospital, University of Duisburg-Essen University of Duisburg-Essen, Essen, Germany
| | - Anja Stein
- 42 Department of Neonatology, University Childrens Hospital, University of Duisburg-Essen, Essen, Germany
| | - Caroline Sewry
- 43 Dubowitz Neuromuscular Centre, Institute of Child Health and Great Ormond Street Hospital, 30 Guilford Street, London WC1N 1EH, UK
| | - Laura Travan
- 44 Institute for Maternal and Child Health, IRCCS 'Burlo Garofolo', Trieste, Italy
| | - Frits A Wijburg
- 45 Department of Paediatrics, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Martin Zenker
- 46 Institute of Human Genetics, University Hospital Magdeburg, Germany
| | - Shehla Mohammed
- 47 Department of Clinical Genetics, Guy's Hospital, London, UK
| | - Manolis Fanto
- 2 Department of Basic and Clinical Neuroscience, IoPPN, King's College London, London, UK
| | - Mathias Gautel
- 6 Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK
| | - Heinz Jungbluth
- 1 Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's and St. Thomas' Hospital NHS Foundation Trust, London, UK 6 Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK 48 Department of Basic and Clinical Neuroscience, IoPPN, King's College London, London, UK
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44
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Abstract
Vici syndrome [OMIM242840] is a severe, recessively inherited congenital disorder characterized by the principal features of callosal agenesis, cataracts, oculocutaneous hypopigmentation, cardiomyopathy, and a combined immunodeficiency. Profound developmental delay, progressive failure to thrive and acquired microcephaly are almost universal, suggesting an evolving (neuro) degenerative component. In most patients there is additional variable multisystem involvement that may affect virtually any organ system, including lungs, thyroid, liver and kidneys. A skeletal myopathy is consistently associated, and characterized by marked fibre type disproportion, increase in internal nuclei, numerous vacuoles, abnormal mitochondria and glycogen storage. Life expectancy is markedly reduced.Vici syndrome is due to recessive mutations in EPG5 on chromosome 18q12.3, encoding ectopic P granules protein 5 (EPG5), a key autophagy regulator in higher organisms. Autophagy is a fundamental cellular degradative pathway conserved throughout evolution with important roles in the removal of defective proteins and organelles, defence against infections and adaptation to changing metabolic demands. Almost 40 EPG mutations have been identified to date, most of them truncating and private to individual families.The differential diagnosis of Vici syndrome includes a number of syndromes with overlapping clinical features, neurological and metabolic disorders with shared CNS abnormalities (in particular callosal agenesis), and primary neuromuscular disorders with a similar muscle biopsy appearance. Vici syndrome is also the most typical example of a novel group of inherited neurometabolic conditions, congenital disorders of autophagy.Management is currently largely supportive and symptomatic but better understanding of the underlying autophagy defect will hopefully inform the development of targeted therapies in future.
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Affiliation(s)
- Susan Byrne
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - Carlo Dionisi-Vici
- Division of Metabolism and Laboratory of Molecular Medicine, Bambino Gesu Children's Hospital IRCCS, Rome, Italy
| | - Luke Smith
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK.
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK.
- Department of Clinical and Basic Neuroscience, IoPPN, King's College, London, UK.
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45
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Katzemich A, West RJH, Fukuzawa A, Sweeney ST, Gautel M, Sparrow J, Bullard B. Binding partners of the kinase domains in Drosophila obscurin and their effect on the structure of the flight muscle. J Cell Sci 2015; 128:3386-97. [PMID: 26251439 DOI: 10.1242/jcs.170639] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 07/27/2015] [Indexed: 01/15/2023] Open
Abstract
Drosophila obscurin (Unc-89) is a titin-like protein in the M-line of the muscle sarcomere. Obscurin has two kinase domains near the C-terminus, both of which are predicted to be inactive. We have identified proteins binding to the kinase domains. Kinase domain 1 bound Bällchen (Ball, an active kinase), and both kinase domains 1 and 2 bound MASK (a 400-kDa protein with ankyrin repeats). Ball was present in the Z-disc and M-line of the indirect flight muscle (IFM) and was diffusely distributed in the sarcomere. MASK was present in both the M-line and the Z-disc. Reducing expression of Ball or MASK by siRNA resulted in abnormalities in the IFM, including missing M-lines and multiple Z-discs. Obscurin was still present, suggesting that the kinase domains act as a scaffold binding Ball and MASK. Unlike obscurin in vertebrate skeletal muscle, Drosophila obscurin is necessary for the correct assembly of the IFM sarcomere. We show that Ball and MASK act downstream of obscurin, and both are needed for development of a well defined M-line and Z-disc. The proteins have not previously been identified in Drosophila muscle.
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Affiliation(s)
- Anja Katzemich
- Department of Biology, University of York, York YO10 5DD, UK
| | - Ryan J H West
- Department of Biology, University of York, York YO10 5DD, UK
| | - Atsushi Fukuzawa
- King's College BHF Centre, Cardiovascular Division, London SE1 1UL, UK
| | - Sean T Sweeney
- Department of Biology, University of York, York YO10 5DD, UK
| | - Mathias Gautel
- King's College BHF Centre, Cardiovascular Division, London SE1 1UL, UK
| | - John Sparrow
- Department of Biology, University of York, York YO10 5DD, UK
| | - Belinda Bullard
- Department of Biology, University of York, York YO10 5DD, UK
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46
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Rokach O, Sekulic-Jablanovic M, Voermans N, Wilmshurst J, Pillay K, Heytens L, Zhou H, Muntoni F, Gautel M, Nevo Y, Mitrani-Rosenbaum S, Attali R, Finotti A, Gambari R, Mosca B, Jungbluth H, Zorzato F, Treves S. Epigenetic changes as a common trigger of muscle weakness in congenital myopathies. Hum Mol Genet 2015; 24:4636-47. [DOI: 10.1093/hmg/ddv195] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 05/22/2015] [Indexed: 12/13/2022] Open
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47
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Rostkova E, Gautel M, Pfuhl M. Solution NMR assignment of the heavy chain complex of the human cardiac myosin regulatory light chain. Biomol NMR Assign 2015; 9:51-53. [PMID: 24414277 DOI: 10.1007/s12104-014-9543-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/04/2014] [Indexed: 06/03/2023]
Abstract
The regulatory light chain (RLC) of striated and cardiac muscle myosin plays a complex role in muscle function and regulation. Together with the essential light chain it provides stability to the lever arm, which is essential for force generation. Furthermore, phosphorylation and interaction with myosin binding protein C (MyBP-C) suggest an additional role in the regulation of muscle contraction. The former is of particular importance in the heart, where RLC phosphorylation appears to be correlated to the wringing motion of heart contraction. To address these questions and because of a lack of mammalian RLC structures, we initiated an NMR study of the human cardiac regulatory myosin light chain.
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Affiliation(s)
- Elena Rostkova
- Cardiovascular and Randall Division, King's College London, Guy's Campus, London, SE1 1UL, UK
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48
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Pernigo S, Fukuzawa A, Pandini A, Holt M, Kleinjung J, Gautel M, Steiner RA. The Crystal Structure of the Human Titin:Obscurin Complex Reveals a Conserved yet Specific Muscle M-Band Zipper Module. J Mol Biol 2015; 427:718-736. [DOI: 10.1016/j.jmb.2014.11.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 11/15/2014] [Accepted: 11/19/2014] [Indexed: 10/24/2022]
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49
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Abstract
Centronuclear myopathies (CNMs) are a genetically heterogeneous group of inherited neuromuscular disorders characterized by clinical features of a congenital myopathy and abundant central nuclei as the most prominent histopathological feature. The most common forms of congenital myopathies with central nuclei have been attributed to X-linked recessive mutations in the MTM1 gene encoding myotubularin (“X-linked myotubular myopathy”), autosomal-dominant mutations in the DNM2 gene encoding dynamin-2 and the BIN1 gene encoding amphiphysin-2 (also named bridging integrator-1, BIN1, or SH3P9), and autosomal-recessive mutations in BIN1, the RYR1 gene encoding the skeletal muscle ryanodine receptor, and the TTN gene encoding titin. Models to study and rescue the affected cellular pathways are now available in yeast, C. elegans, drosophila, zebrafish, mouse, and dog. Defects in membrane trafficking have emerged as a key pathogenic mechanisms, with aberrant T-tubule formation, abnormalities of triadic assembly, and disturbance of the excitation–contraction machinery the main downstream effects studied to date. Abnormal autophagy has recently been recognized as another important collateral of defective membrane trafficking in different genetic forms of CNM, suggesting an intriguing link to primary disorders of defective autophagy with overlapping histopathological features. The following review will provide an overview of clinical, histopathological, and genetic aspects of the CNMs in the context of the key pathogenic mechanism, outline unresolved questions, and indicate promising future lines of enquiry.
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Affiliation(s)
- Heinz Jungbluth
- Neuromuscular Service, Department of Paediatric Neurology, Evelina Children's Hospital, St Thomas' Hospital , London , UK ; Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London , London , UK ; Randall Division of Cell and Molecular Biophysics and Cardiovascular Division, King's College London BHF Centre of Research Excellence , London , UK
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics and Cardiovascular Division, King's College London BHF Centre of Research Excellence , London , UK
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50
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Ribeiro EDA, Pinotsis N, Ghisleni A, Salmazo A, Konarev PV, Kostan J, Sjöblom B, Schreiner C, Polyansky AA, Gkougkoulia EA, Holt MR, Aachmann FL, Zagrović B, Bordignon E, Pirker KF, Svergun DI, Gautel M, Djinović-Carugo K. The structure and regulation of human muscle α-actinin. Cell 2014; 159:1447-60. [PMID: 25433700 PMCID: PMC4259493 DOI: 10.1016/j.cell.2014.10.056] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 10/01/2014] [Accepted: 10/24/2014] [Indexed: 11/29/2022]
Abstract
The spectrin superfamily of proteins plays key roles in assembling the actin cytoskeleton in various cell types, crosslinks actin filaments, and acts as scaffolds for the assembly of large protein complexes involved in structural integrity and mechanosensation, as well as cell signaling. α-actinins in particular are the major actin crosslinkers in muscle Z-disks, focal adhesions, and actin stress fibers. We report a complete high-resolution structure of the 200 kDa α-actinin-2 dimer from striated muscle and explore its functional implications on the biochemical and cellular level. The structure provides insight into the phosphoinositide-based mechanism controlling its interaction with sarcomeric proteins such as titin, lays a foundation for studying the impact of pathogenic mutations at molecular resolution, and is likely to be broadly relevant for the regulation of spectrin-like proteins. Structure of human α-actinin-2 in an autoinhibited closed conformation Facilitation of PIP2-induced allosteric modulation for opening and titin binding Essentiality of structural flexibility for crosslinking antiparallel F-actin Relevance for the intramolecular pseudoligand regulation mechanism of the spectrin family
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Affiliation(s)
- Euripedes de Almeida Ribeiro
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Nikos Pinotsis
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Andrea Ghisleni
- British Heart Foundation Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK
| | - Anita Salmazo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Petr V Konarev
- European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
| | - Julius Kostan
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Björn Sjöblom
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Claudia Schreiner
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Anton A Polyansky
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria; M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - Eirini A Gkougkoulia
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Mark R Holt
- British Heart Foundation Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK
| | - Finn L Aachmann
- Department of Biotechnology, Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491 Trondheim, Norway
| | - Bojan Zagrović
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Enrica Bordignon
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland; Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Katharina F Pirker
- Division of Biochemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Dmitri I Svergun
- European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
| | - Mathias Gautel
- British Heart Foundation Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK.
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria; Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia.
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