1
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Bodt SML, Ge J, Ma W, Rasicci DV, Desetty R, McCammon JA, Yengo CM. Dilated cardiomyopathy mutation in beta-cardiac myosin enhances actin activation of the power stroke and phosphate release. PNAS NEXUS 2024; 3:pgae279. [PMID: 39108304 PMCID: PMC11302452 DOI: 10.1093/pnasnexus/pgae279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 06/25/2024] [Indexed: 08/13/2024]
Abstract
Inherited mutations in human beta-cardiac myosin (M2β) can lead to severe forms of heart failure. The E525K mutation in M2β is associated with dilated cardiomyopathy (DCM) and was found to stabilize the interacting heads motif (IHM) and autoinhibited super-relaxed (SRX) state in dimeric heavy meromyosin. However, in monomeric M2β subfragment 1 (S1) we found that E525K enhances (threefold) the maximum steady-state actin-activated ATPase activity (k cat) and decreases (eightfold) the actin concentration at which ATPase is one-half maximal (K ATPase). We also found a twofold to fourfold increase in the actin-activated power stroke and phosphate release rate constants at 30 μM actin, which overall enhanced the duty ratio threefold. Loaded motility assays revealed that the enhanced intrinsic motor activity translates to increased ensemble force in M2β S1. Glutamate 525, located near the actin binding region in the so-called activation loop, is highly conserved and predicted to form a salt bridge with another conserved residue (lysine 484) in the relay helix. Enhanced sampling molecular dynamics simulations predict that the charge reversal mutation disrupts the E525-K484 salt bridge, inducing conformations with a more flexible relay helix and a wide phosphate release tunnel. Our results highlight a highly conserved allosteric pathway associated with actin activation of the power stroke and phosphate release and suggest an important feature of the autoinhibited IHM is to prevent this region of myosin from interacting with actin. The ability of the E525K mutation to stabilize the IHM likely overrides the enhanced intrinsic motor properties, which may be key to triggering DCM pathogenesis.
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Affiliation(s)
- Skylar M L Bodt
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, 500 University Dr, Hershey, PA 17033, USA
| | - Jinghua Ge
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, 500 University Dr, Hershey, PA 17033, USA
| | - Wen Ma
- Department of Physics, University of Vermont, 149 Beaumont Avenue, Burlington, VT 05405, USA
| | - David V Rasicci
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, 500 University Dr, Hershey, PA 17033, USA
- Department of Pathology, Anatomy, and Laboratory Medicine, West Virginia University School of Medicine, 64 Medical Center Dr, Morgantown, WV 26506, USA
| | - Rohini Desetty
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, 500 University Dr, Hershey, PA 17033, USA
| | - J Andrew McCammon
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, 500 University Dr, Hershey, PA 17033, USA
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2
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Childers MC, Geeves MA, Regnier M. An atomistic model of myosin interacting heads motif dynamics and their modification by 2'-deoxy-ADP. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.06.597809. [PMID: 38895221 PMCID: PMC11185614 DOI: 10.1101/2024.06.06.597809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
The contraction of striated muscle is driven by cycling myosin motor proteins embedded within the thick filaments of sarcomeres. In addition to cross-bridge cycling with actin, these myosin proteins can enter an inactive, sequestered state in which the globular S1 heads rest along the thick filament surface and are unable to perform motor activities. Structurally, this state is called the interacting heads motif (IHM) and is a critical conformational state of myosin that regulates muscle contractility and energy expenditure. Structural perturbation of the sequestered state via missense mutations can pathologically disrupt the mechanical performance of muscle tissue. Thus, the IHM state has become a target for therapeutic intervention. An ATP analogue called 2'-deoxy-ATP (dATP) is a potent myosin activator which destabilizes the IHM. Here we use molecular dynamics simulations to study the molecular mechanisms by which dATP modifies the structure and dynamics of myosin in a sequestered state. Simulations with IHM containing ADP.Pi in both nucleotide binding pockets revealed residual dynamics in an otherwise 'inactive' and 'sequestered' state of a motor protein. Replacement of ADP.Pi by dADP.Pi triggered a series of structural changes that modify the protein-protein interface that stabilizes the sequestered state, and changes to this interface were accompanied by allosteric changes in remote regions of the protein complex. A comparative analysis of these dynamics predicted new structural sites that may affect IHM stability.
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3
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Auguin D, Robert-Paganin J, Réty S, Kikuti C, David A, Theumer G, Schmidt AW, Knölker HJ, Houdusse A. Omecamtiv mecarbil and Mavacamten target the same myosin pocket despite opposite effects in heart contraction. Nat Commun 2024; 15:4885. [PMID: 38849353 PMCID: PMC11161628 DOI: 10.1038/s41467-024-47587-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 04/03/2024] [Indexed: 06/09/2024] Open
Abstract
Inherited cardiomyopathies are common cardiac diseases worldwide, leading in the late stage to heart failure and death. The most promising treatments against these diseases are small molecules directly modulating the force produced by β-cardiac myosin, the molecular motor driving heart contraction. Omecamtiv mecarbil and Mavacamten are two such molecules that completed phase 3 clinical trials, and the inhibitor Mavacamten is now approved by the FDA. In contrast to Mavacamten, Omecamtiv mecarbil acts as an activator of cardiac contractility. Here, we reveal by X-ray crystallography that both drugs target the same pocket and stabilize a pre-stroke structural state, with only few local differences. All-atom molecular dynamics simulations reveal how these molecules produce distinct effects in motor allostery thus impacting force production in opposite way. Altogether, our results provide the framework for rational drug development for the purpose of personalized medicine.
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Affiliation(s)
- Daniel Auguin
- Structural Motility, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, CNRS UMR144, Paris, 75248, France
- Laboratoire de Physiologie, Ecologie et Environnement (P2E), UPRES EA 1207/USC INRAE-1328, UFR Sciences et Techniques, Université d'Orléans, Orléans, France
| | - Julien Robert-Paganin
- Structural Motility, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, CNRS UMR144, Paris, 75248, France
| | - Stéphane Réty
- Laboratoire de Biologie et Modélisation de la Cellule, ENS de Lyon, CNRS, UMR 5239, Inserm, U1293, Université Claude Bernard Lyon 1, Lyon, France
| | - Carlos Kikuti
- Structural Motility, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, CNRS UMR144, Paris, 75248, France
| | - Amandine David
- Structural Motility, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, CNRS UMR144, Paris, 75248, France
| | | | | | | | - Anne Houdusse
- Structural Motility, Institut Curie, Université Paris Sciences et Lettres, Sorbonne Université, CNRS UMR144, Paris, 75248, France.
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4
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Duno-Miranda S, Nelson SR, Rasicci DV, Bodt SM, Cirilo JA, Vang D, Sivaramakrishnan S, Yengo CM, Warshaw DM. Tail length and E525K dilated cardiomyopathy mutant alter human β-cardiac myosin super-relaxed state. J Gen Physiol 2024; 156:e202313522. [PMID: 38709176 PMCID: PMC11074782 DOI: 10.1085/jgp.202313522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/18/2024] [Accepted: 04/17/2024] [Indexed: 05/07/2024] Open
Abstract
Dilated cardiomyopathy (DCM) is a condition characterized by impaired cardiac function, due to myocardial hypo-contractility, and is associated with point mutations in β-cardiac myosin, the molecular motor that powers cardiac contraction. Myocardial function can be modulated through sequestration of myosin motors into an auto-inhibited "super-relaxed" state (SRX), which may be further stabilized by a structural state known as the "interacting heads motif" (IHM). Here, we sought to determine whether hypo-contractility of DCM myocardium results from reduced function of individual myosin molecules or from decreased myosin availability to interact with actin due to increased IHM/SRX stabilization. We used an established DCM myosin mutation, E525K, and characterized the biochemical and mechanical activity of wild-type and mutant human β-cardiac myosin constructs that differed in the length of their coiled-coil tail, which dictates their ability to form the IHM/SRX state. We found that short-tailed myosin constructs exhibited low IHM/SRX content, elevated actin-activated ATPase activity, and fast velocities in unloaded motility assays. Conversely, longer-tailed constructs exhibited higher IHM/SRX content and reduced actomyosin ATPase and velocity. Our modeling suggests that reduced velocities may be attributed to IHM/SRX-dependent sequestration of myosin heads. Interestingly, longer-tailed E525K mutants showed no apparent impact on velocity or actomyosin ATPase at low ionic strength but stabilized IHM/SRX state at higher ionic strength. Therefore, the hypo-contractility observed in DCM may be attributable to reduced myosin head availability caused by enhanced IHM/SRX stability in E525K mutants.
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Affiliation(s)
- Sebastian Duno-Miranda
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT, USA
| | - Shane R. Nelson
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT, USA
| | - David V. Rasicci
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - Skylar M.L. Bodt
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - Joseph A. Cirilo
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - Duha Vang
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Sivaraj Sivaramakrishnan
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA
| | - Christopher M. Yengo
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - David M. Warshaw
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT, USA
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5
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Lewis CTA, Melhedegaard EG, Ognjanovic MM, Olsen MS, Laitila J, Seaborne RAE, Gronset M, Zhang C, Iwamoto H, Hessel AL, Kuehn MN, Merino C, Amigo N, Frobert O, Giroud S, Staples JF, Goropashnaya AV, Fedorov VB, Barnes B, Toien O, Drew K, Sprenger RJ, Ochala J. Remodeling of skeletal muscle myosin metabolic states in hibernating mammals. eLife 2024; 13:RP94616. [PMID: 38752835 PMCID: PMC11098559 DOI: 10.7554/elife.94616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024] Open
Abstract
Hibernation is a period of metabolic suppression utilized by many small and large mammal species to survive during winter periods. As the underlying cellular and molecular mechanisms remain incompletely understood, our study aimed to determine whether skeletal muscle myosin and its metabolic efficiency undergo alterations during hibernation to optimize energy utilization. We isolated muscle fibers from small hibernators, Ictidomys tridecemlineatus and Eliomys quercinus and larger hibernators, Ursus arctos and Ursus americanus. We then conducted loaded Mant-ATP chase experiments alongside X-ray diffraction to measure resting myosin dynamics and its ATP demand. In parallel, we performed multiple proteomics analyses. Our results showed a preservation of myosin structure in U. arctos and U. americanus during hibernation, whilst in I. tridecemlineatus and E. quercinus, changes in myosin metabolic states during torpor unexpectedly led to higher levels in energy expenditure of type II, fast-twitch muscle fibers at ambient lab temperatures (20 °C). Upon repeating loaded Mant-ATP chase experiments at 8 °C (near the body temperature of torpid animals), we found that myosin ATP consumption in type II muscle fibers was reduced by 77-107% during torpor compared to active periods. Additionally, we observed Myh2 hyper-phosphorylation during torpor in I. tridecemilineatus, which was predicted to stabilize the myosin molecule. This may act as a potential molecular mechanism mitigating myosin-associated increases in skeletal muscle energy expenditure during periods of torpor in response to cold exposure. Altogether, we demonstrate that resting myosin is altered in hibernating mammals, contributing to significant changes to the ATP consumption of skeletal muscle. Additionally, we observe that it is further altered in response to cold exposure and highlight myosin as a potentially contributor to skeletal muscle non-shivering thermogenesis.
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Affiliation(s)
| | | | - Marija M Ognjanovic
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
| | - Mathilde S Olsen
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
| | - Jenni Laitila
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
| | - Robert AE Seaborne
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King’s College LondonLondonUnited Kingdom
| | - Magnus Gronset
- Department of Cellular and Molecular Medicine, University of CopenhagenCopenhagenDenmark
| | - Changxin Zhang
- Department of Computational Medicine and Bioinformatics, University of MichiganAnn ArborUnited States
| | - Hiroyuki Iwamoto
- Spring-8, Japan Synchrotron Radiation Research InstituteHyogoJapan
| | - Anthony L Hessel
- Institute of Physiology II, University of MuensterMuensterGermany
- Accelerated Muscle Biotechnologies ConsultantsBostonUnited States
| | - Michel N Kuehn
- Institute of Physiology II, University of MuensterMuensterGermany
- Accelerated Muscle Biotechnologies ConsultantsBostonUnited States
| | | | | | - Ole Frobert
- Department of Clinical Medicine, Faculty of Health, Aarhus UniversityAarhusDenmark
- Faculty of Health, Department of Cardiology, Örebro UniversityÖrebroSweden
| | - Sylvain Giroud
- Energetics Lab, Department of Biology, Northern Michigan UniversityMarquetteUnited States
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine ViennaViennaAustria
| | - James F Staples
- Department of Biology, University of Western OntarioLondonCanada
| | - Anna V Goropashnaya
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Vadim B Fedorov
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Brian Barnes
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Oivind Toien
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Kelly Drew
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Ryan J Sprenger
- Department of Zoology, University of British ColumbiaVancouverCanada
| | - Julien Ochala
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
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6
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Hessel AL, Engels NM, Kuehn MN, Nissen D, Sadler RL, Ma W, Irving TC, Linke WA, Harris SP. Myosin-binding protein C regulates the sarcomere lattice and stabilizes the OFF states of myosin heads. Nat Commun 2024; 15:2628. [PMID: 38521794 PMCID: PMC10960836 DOI: 10.1038/s41467-024-46957-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/15/2024] [Indexed: 03/25/2024] Open
Abstract
Muscle contraction is produced via the interaction of myofilaments and is regulated so that muscle performance matches demand. Myosin-binding protein C (MyBP-C) is a long and flexible protein that is tightly bound to the thick filament at its C-terminal end (MyBP-CC8C10), but may be loosely bound at its middle- and N-terminal end (MyBP-CC1C7) to myosin heads and/or the thin filament. MyBP-C is thought to control muscle contraction via the regulation of myosin motors, as mutations lead to debilitating disease. We use a combination of mechanics and small-angle X-ray diffraction to study the immediate and selective removal of the MyBP-CC1C7 domains of fast MyBP-C in permeabilized skeletal muscle. We show that cleavage leads to alterations in crossbridge kinetics and passive structural signatures of myofilaments that are indicative of a shift of myosin heads towards the ON state, highlighting the importance of MyBP-CC1C7 to myofilament force production and regulation.
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Affiliation(s)
- Anthony L Hessel
- Institute of Physiology II, University of Muenster, Muenster, Germany.
- Accelerated Muscle Biotechnologies Consultants, Boston, MA, USA.
| | - Nichlas M Engels
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Michel N Kuehn
- Institute of Physiology II, University of Muenster, Muenster, Germany
- Accelerated Muscle Biotechnologies Consultants, Boston, MA, USA
| | - Devin Nissen
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL, USA
| | - Rachel L Sadler
- Department of Physiology, University of Arizona, Tucson, AZ, USA
| | - Weikang Ma
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL, USA
| | - Thomas C Irving
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL, USA
| | - Wolfgang A Linke
- Institute of Physiology II, University of Muenster, Muenster, Germany
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7
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Burnham HV, Cizauskas HE, Barefield DY. Fine tuning contractility: atrial sarcomere function in health and disease. Am J Physiol Heart Circ Physiol 2024; 326:H568-H583. [PMID: 38156887 PMCID: PMC11221815 DOI: 10.1152/ajpheart.00252.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
The molecular mechanisms of sarcomere proteins underlie the contractile function of the heart. Although our understanding of the sarcomere has grown tremendously, the focus has been on ventricular sarcomere isoforms due to the critical role of the ventricle in health and disease. However, atrial-specific or -enriched myofilament protein isoforms, as well as isoforms that become expressed in disease, provide insight into ways this complex molecular machine is fine-tuned. Here, we explore how atrial-enriched sarcomere protein composition modulates contractile function to fulfill the physiological requirements of atrial function. We review how atrial dysfunction negatively affects the ventricle and the many cardiovascular diseases that have atrial dysfunction as a comorbidity. We also cover the pathophysiology of mutations in atrial-enriched contractile proteins and how they can cause primary atrial myopathies. Finally, we explore what is known about contractile function in various forms of atrial fibrillation. The differences in atrial function in health and disease underscore the importance of better studying atrial contractility, especially as therapeutics currently in development to modulate cardiac contractility may have different effects on atrial sarcomere function.
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Affiliation(s)
- Hope V Burnham
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois, United States
| | - Hannah E Cizauskas
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois, United States
| | - David Y Barefield
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois, United States
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8
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Lewis CTA, Melhedegaard EG, Ognjanovic MM, Olsen MS, Laitila J, Seaborne RAE, Gronset MN, Zhang C, Iwamoto H, Hessel AL, Kuehn MN, Merino C, Amigo N, Frobert O, Giroud S, Staples JF, Goropashnaya AV, Fedorov VB, Barnes BM, Toien O, Drew KL, Sprenger RJ, Ochala J. Remodelling of Skeletal Muscle Myosin Metabolic States in Hibernating Mammals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.14.566992. [PMID: 38014200 PMCID: PMC10680686 DOI: 10.1101/2023.11.14.566992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Hibernation is a period of metabolic suppression utilized by many small and large mammal species to survive during winter periods. As the underlying cellular and molecular mechanisms remain incompletely understood, our study aimed to determine whether skeletal muscle myosin and its metabolic efficiency undergo alterations during hibernation to optimize energy utilization. We isolated muscle fibers from small hibernators, Ictidomys tridecemlineatus and Eliomys quercinus and larger hibernators, Ursus arctos and Ursus americanus. We then conducted loaded Mant-ATP chase experiments alongside X-ray diffraction to measure resting myosin dynamics and its ATP demand. In parallel, we performed multiple proteomics analyses. Our results showed a preservation of myosin structure in U. arctos and U. americanus during hibernation, whilst in I. tridecemlineatus and E. quercinus, changes in myosin metabolic states during torpor unexpectedly led to higher levels in energy expenditure of type II, fast-twitch muscle fibers at ambient lab temperatures (20°C). Upon repeating loaded Mant-ATP chase experiments at 8°C (near the body temperature of torpid animals), we found that myosin ATP consumption in type II muscle fibers was reduced by 77-107% during torpor compared to active periods. Additionally, we observed Myh2 hyper-phosphorylation during torpor in I. tridecemilineatus, which was predicted to stabilize the myosin molecule. This may act as a potential molecular mechanism mitigating myosin-associated increases in skeletal muscle energy expenditure during periods of torpor in response to cold exposure. Altogether, we demonstrate that resting myosin is altered in hibernating mammals, contributing to significant changes to the ATP consumption of skeletal muscle. Additionally, we observe that it is further altered in response to cold exposure and highlight myosin as a potentially contributor to skeletal muscle non-shivering thermogenesis.
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9
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Abstract
Force generation in striated muscle is primarily controlled by structural changes in the actin-containing thin filaments triggered by an increase in intracellular calcium concentration. However, recent studies have elucidated a new class of regulatory mechanisms, based on the myosin-containing thick filament, that control the strength and speed of contraction by modulating the availability of myosin motors for the interaction with actin. This review summarizes the mechanisms of thin and thick filament activation that regulate the contractility of skeletal and cardiac muscle. A novel dual-filament paradigm of muscle regulation is emerging, in which the dynamics of force generation depends on the coordinated activation of thin and thick filaments. We highlight the interfilament signaling pathways based on titin and myosin-binding protein-C that couple thin and thick filament regulatory mechanisms. This dual-filament regulation mediates the length-dependent activation of cardiac muscle that underlies the control of the cardiac output in each heartbeat.
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Affiliation(s)
- Elisabetta Brunello
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences and British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom; ,
| | - Luca Fusi
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences and British Heart Foundation Centre of Research Excellence, King's College London, London, United Kingdom; ,
- Centre for Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, King's College London, London, United Kingdom
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10
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Niu F, Li L, Wang L, Xiao J, Xu S, Liu Y, Lin L, Yu C, Wei Z. Autoinhibition and activation of myosin VI revealed by its cryo-EM structure. Nat Commun 2024; 15:1187. [PMID: 38331992 PMCID: PMC10853514 DOI: 10.1038/s41467-024-45424-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 01/23/2024] [Indexed: 02/10/2024] Open
Abstract
Myosin VI is the only molecular motor that moves towards the minus end along actin filaments. Numerous cellular processes require myosin VI and tight regulations of the motor's activity. Defects in myosin VI activity are known to cause genetic diseases such as deafness and cardiomyopathy. However, the molecular mechanisms underlying the activity regulation of myosin VI remain elusive. Here, we determined the high-resolution cryo-electron microscopic structure of myosin VI in its autoinhibited state. Our structure reveals that autoinhibited myosin VI adopts a compact, monomeric conformation via extensive interactions between the head and tail domains, orchestrated by an elongated single-α-helix region resembling a "spine". This autoinhibited structure effectively blocks cargo binding sites and represses the motor's ATPase activity. Certain cargo adaptors such as GIPC can release multiple inhibitory interactions and promote motor activity, pointing to a cargo-mediated activation of the processive motor. Moreover, our structural findings allow rationalization of disease-associated mutations in myosin VI. Beyond the activity regulation mechanisms of myosin VI, our study also sheds lights on how activities of other myosin motors such as myosin VII and X might be regulated.
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Affiliation(s)
- Fengfeng Niu
- Department of Neuroscience and Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Shenzhen Key Laboratory of Biomolecular Assembling and Regulation, Shenzhen, Guangdong, China
| | - Lingxuan Li
- Department of Neuroscience and Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Lei Wang
- Department of Neuroscience and Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Jinman Xiao
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, Guangdong, China
| | - Shun Xu
- Department of Neuroscience and Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yong Liu
- Department of Neuroscience and Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Leishu Lin
- Department of Neuroscience and Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Cong Yu
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China.
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, Guangdong, China.
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, Guangdong, China.
| | - Zhiyi Wei
- Department of Neuroscience and Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China.
- Shenzhen Key Laboratory of Biomolecular Assembling and Regulation, Shenzhen, Guangdong, China.
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, Guangdong, China.
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11
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Chiba K, Niwa S. Autoinhibition and activation of kinesin-1 and their involvement in amyotrophic lateral sclerosis. Curr Opin Cell Biol 2024; 86:102301. [PMID: 38096601 DOI: 10.1016/j.ceb.2023.102301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 11/11/2023] [Accepted: 11/22/2023] [Indexed: 02/15/2024]
Abstract
Kinesin-1, composed of kinesin heavy chain and kinesin light chain, is a founding member of kinesin superfamily and transports various neuronal cargos. Kinesin-1 is one of the most abundant ATPases in the cell and thus need to be tightly regulated to avoid wastage of energy. It has been well established that kinesin-1 is regulated by the autoinhibition mechanism. This review focuses on the recent researches that have contributed to the understanding of mechanisms for the autoinhibition of kinesin-1 and its unlocking. Recent electron microscopic studies have shown an unanticipated structure of autoinhibited kinesin-1. Biochemical reconstitution have revealed detailed molecular mechanisms how the autoinhibition is unlocked. Importantly, misregulation of kinesin-1 is emerging as one of the major causes of amyotrophic lateral sclerosis.
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Affiliation(s)
- Kyoko Chiba
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi 980-0845, Japan
| | - Shinsuke Niwa
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi 980-0845, Japan; Graduate School of Life Sciences, Tohoku University, 2-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
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12
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Mohran S, Kooiker K, Mahoney-Schaefer M, Mandrycky C, Kao K, Tu AY, Freeman J, Moussavi-Harami F, Geeves M, Regnier M. The biochemically defined super relaxed state of myosin-A paradox. J Biol Chem 2024; 300:105565. [PMID: 38103642 PMCID: PMC10819765 DOI: 10.1016/j.jbc.2023.105565] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/06/2023] [Accepted: 12/06/2023] [Indexed: 12/19/2023] Open
Abstract
The biochemical SRX (super-relaxed) state of myosin has been defined as a low ATPase activity state. This state can conserve energy when the myosin is not recruited for muscle contraction. The SRX state has been correlated with a structurally defined ordered (versus disordered) state of muscle thick filaments. The two states may be linked via a common interacting head motif (IHM) where the two heads of heavy meromyosin (HMM), or myosin, fold back onto each other and form additional contacts with S2 and the thick filament. Experimental observations of the SRX, IHM, and the ordered form of thick filaments, however, do not always agree, and result in a series of unresolved paradoxes. To address these paradoxes, we have reexamined the biochemical measurements of the SRX state for porcine cardiac HMM. In our hands, the commonly employed mantATP displacement assay was unable to quantify the population of the SRX state with all data fitting very well by a single exponential. We further show that mavacamten inhibits the basal ATPases of both porcine ventricle HMM and S1 (Ki, 0.32 and 1.76 μM respectively) while dATP activates HMM cooperatively without any evidence of an SRX state. A combination of our experimental observations and theories suggests that the displacement of mantATP in purified proteins is not a reliable assay to quantify the SRX population. This means that while the structurally defined IHM and ordered thick filaments clearly exist, great care must be employed when using the mantATP displacement assay.
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Affiliation(s)
- Saffie Mohran
- Department of Bioengineering, University of Washington, Seattle, Washington, USA; Center for Translational Muscle Research, University of Washington, Seattle, Washington, USA
| | - Kristina Kooiker
- Center for Translational Muscle Research, University of Washington, Seattle, Washington, USA; Division of Cardiology, University of Washington, Seattle, Washington, USA
| | | | - Christian Mandrycky
- Department of Bioengineering, University of Washington, Seattle, Washington, USA; Center for Translational Muscle Research, University of Washington, Seattle, Washington, USA
| | - Kerry Kao
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - An-Yue Tu
- Department of Bioengineering, University of Washington, Seattle, Washington, USA; Center for Translational Muscle Research, University of Washington, Seattle, Washington, USA
| | - Jeremy Freeman
- Division of Cardiology, University of Washington, Seattle, Washington, USA
| | - Farid Moussavi-Harami
- Department of Bioengineering, University of Washington, Seattle, Washington, USA; Center for Translational Muscle Research, University of Washington, Seattle, Washington, USA; Division of Cardiology, University of Washington, Seattle, Washington, USA
| | - Michael Geeves
- School of Biosciences, University of Kent, Canterbury, UK.
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, Washington, USA; Center for Translational Muscle Research, University of Washington, Seattle, Washington, USA.
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13
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Heeley DH, Belknap B, Atherton JL, Hasan SC, White HD. Effect of the N-terminal extension in myosin essential light chain A1 on the mechanism of actomyosin ATP hydrolysis. J Biol Chem 2024; 300:105521. [PMID: 38042484 PMCID: PMC10777021 DOI: 10.1016/j.jbc.2023.105521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 11/22/2023] [Accepted: 11/24/2023] [Indexed: 12/04/2023] Open
Abstract
Myosin essential light chains A1 and A2 are identical isoforms except for an extension of ∼40 amino acids at the N terminus of A1 that binds F-actin. The extension has no bearing on the burst hydrolysis rate (M-ATP → M-ADP-Pi) as determined by chemical quench flow (100 μM isoenzyme). Whereas actomyosin-S1A2 steady state MgATPase (low ionic strength, 20 °C) is hyperbolically dependent on concentration: Vmax 7.6 s-1, Kapp 6.4 μM (F-actin) and Vmax 10.1 s-1, Kapp 5.5 μM (native thin filaments, pCa 4), the relationship for myosin-S1A1 is bimodal; an initial rise at low concentration followed by a decline to one-third the Vmax of S1A2, indicative of more than one rate-limiting step and A1-enforced flux through the slower actomyosin-limited hydrolysis pathway. In double-mixing stopped-flow with an indicator, Ca(II)-mediated activation of Pi dissociation (regulatedAM-ADP-Pi → regulatedAM-ADP + Pi) is attenuated by A1 attachment to thin filaments (pCa 4). The maximum accelerated rates of Pi dissociation are: 81 s-1 (S1A1, Kapp 8.9 μM) versus 129 s-1 (S1A2, Kapp 58 μM). To investigate apomyosin-S1-mediated activation, thin filaments (EGTA) are premixed with a given isomyosin-S1 and double-mixing is repeated with myosin-S1A1 in the first mix. Similar maximum rates of Pi dissociation are observed, 44.5 s-1 (S1A1) and 47.1 s-1 (S1A2), which are lower than for Ca(II) activation. Overall, these results biochemically demonstrate how the longer light chain A1 can contribute to slower contraction and higher force and the shorter version A2 to faster contraction and lower force, consistent with their distribution in different types of striated muscle.
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Affiliation(s)
- David H Heeley
- Department of Biochemistry, Memorial University, St John's, Newfoundland, Canada.
| | - Betty Belknap
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia, USA
| | - Jennifer L Atherton
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia, USA
| | - Stephanie C Hasan
- Department of Biochemistry, Memorial University, St John's, Newfoundland, Canada
| | - Howard D White
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia, USA
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14
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Duno-Miranda S, Nelson SR, Rasicci DV, Bodt SL, Cirilo JA, Vang D, Sivaramakrishnan S, Yengo CM, Warshaw DM. Tail Length and E525K Dilated Cardiomyopathy Mutant Alter Human β-Cardiac Myosin Super-Relaxed State. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.07.570656. [PMID: 38105932 PMCID: PMC10723396 DOI: 10.1101/2023.12.07.570656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Dilated cardiomyopathy (DCM) is characterized by impaired cardiac function due to myocardial hypo-contractility and is associated with point mutations in β-cardiac myosin, the molecular motor that powers cardiac contraction. Myocardial function can be modulated through sequestration of myosin motors into an auto-inhibited "super relaxed" state (SRX), which is further stabilized by a structural state known as the "Interacting Heads Motif" (IHM). Therefore, hypo-contractility of DCM myocardium may result from: 1) reduced function of individual myosin, and/or; 2) decreased myosin availability due to increased IHM/SRX stabilization. To define the molecular impact of an established DCM myosin mutation, E525K, we characterized the biochemical and mechanical activity of wild-type (WT) and E525K human β-cardiac myosin constructs that differed in the length of their coiled-coil tail, which dictates their ability to form the IHM/SRX state. Single-headed (S1) and a short-tailed, double-headed (2HEP) myosin constructs exhibited low (~10%) IHM/SRX content, actin-activated ATPase activity of ~5s-1 and fast velocities in unloaded motility assays (~2000nm/s). Double-headed, longer-tailed (15HEP, 25HEP) constructs exhibited higher IHM/SRX content (~90%), and reduced actomyosin ATPase (<1s-1) and velocity (~800nm/s). A simple analytical model suggests that reduced velocities may be attributed to IHM/SRXdependent sequestration of myosin heads. Interestingly, the E525K 15HEP and 25HEP mutants showed no apparent impact on velocity or actomyosin ATPase at low ionic strength. However, at higher ionic strength, the E525K mutation stabilized the IHM/SRX state. Therefore, the E525K-associated DCM human cardiac hypo-contractility may be attributable to reduced myosin head availability caused by enhanced IHM/SRX stability.
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Affiliation(s)
- Sebastian Duno-Miranda
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, Vermont
| | - Shane R. Nelson
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, Vermont
| | - David V. Rasicci
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Skylar L.M. Bodt
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Joseph A. Cirilo
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Duha Vang
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota
| | - Sivaraj Sivaramakrishnan
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota
| | - Christopher M. Yengo
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
| | - David M. Warshaw
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, Vermont
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15
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Auguin D, Robert-Paganin J, Réty S, Kikuti C, David A, Theumer G, Schmidt AW, Knölker HJ, Houdusse A. Omecamtiv mecarbil and Mavacamten target the same myosin pocket despite antagonistic effects in heart contraction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.15.567213. [PMID: 38014327 PMCID: PMC10680719 DOI: 10.1101/2023.11.15.567213] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Inherited cardiomyopathies are amongst the most common cardiac diseases worldwide, leading in the late-stage to heart failure and death. The most promising treatments against these diseases are small-molecules directly modulating the force produced by β-cardiac myosin, the molecular motor driving heart contraction. Two of these molecules that produce antagonistic effects on cardiac contractility have completed clinical phase 3 trials: the activator Omecamtiv mecarbil and the inhibitor Mavacamten. In this work, we reveal by X-ray crystallography that both drugs target the same pocket and stabilize a pre-stroke structural state, with only few local differences. All atoms molecular dynamics simulations reveal how these molecules can have antagonistic impact on the allostery of the motor by comparing β-cardiac myosin in the apo form or bound to Omecamtiv mecarbil or Mavacamten. Altogether, our results provide the framework for rational drug development for the purpose of personalized medicine.
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Affiliation(s)
- Daniel Auguin
- Structural Motility, UMR 144 CNRS/Curie Institute, PSL Research University, 26 rue d'Ulm, 75258 Paris cedex 05, France
- Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d'Orléans, UPRES EA 1207, INRAE- USC1328, F-45067 Orléans, France
| | - Julien Robert-Paganin
- Structural Motility, UMR 144 CNRS/Curie Institute, PSL Research University, 26 rue d'Ulm, 75258 Paris cedex 05, France
| | - Stéphane Réty
- Laboratoire de Biologie et Modélisation de la Cellule, ENS de Lyon, University Claude Bernard, CNRS UMR 5239, INSERM U1210, 46 Allée d'Italie Site Jacques Monod, F-69007 Lyon, France
| | - Carlos Kikuti
- Structural Motility, UMR 144 CNRS/Curie Institute, PSL Research University, 26 rue d'Ulm, 75258 Paris cedex 05, France
| | - Amandine David
- Structural Motility, UMR 144 CNRS/Curie Institute, PSL Research University, 26 rue d'Ulm, 75258 Paris cedex 05, France
| | - Gabriele Theumer
- Faculty of Chemistry, TU Dresden, Bergstraße 66, 01069 Dresden, Germany
| | - Arndt W Schmidt
- Faculty of Chemistry, TU Dresden, Bergstraße 66, 01069 Dresden, Germany
| | | | - Anne Houdusse
- Structural Motility, UMR 144 CNRS/Curie Institute, PSL Research University, 26 rue d'Ulm, 75258 Paris cedex 05, France
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16
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Bodt SML, Ge J, Ma W, Rasicci DV, Desetty R, McCammon JA, Yengo CM. Dilated cardiomyopathy mutation in beta-cardiac myosin enhances actin activation of the power stroke and phosphate release. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.10.566646. [PMID: 38014187 PMCID: PMC10680644 DOI: 10.1101/2023.11.10.566646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Inherited mutations in human beta-cardiac myosin (M2β) can lead to severe forms of heart failure. The E525K mutation in M2β is associated with dilated cardiomyopathy (DCM) and was found to stabilize the interacting heads motif (IHM) and autoinhibited super-relaxed (SRX) state in dimeric heavy meromyosin. However, in monomeric M2β subfragment 1 (S1) we found that E525K enhances (3-fold) the maximum steady-state actin-activated ATPase activity (kcat) and decreases (6-fold) the actin concentration at which ATPase is one-half maximal (KATPase). We also found a 3 to 4-fold increase in the actin-activated power stroke and phosphate release rate constants at 30 μM actin, which overall enhanced the duty ratio 3-fold. Loaded motility assays revealed that the enhanced intrinsic motor activity translates to increased ensemble force in M2β S1. Glutamate 525, located near the actin binding region in the so-called activation loop, is highly conserved and predicted to form a salt-bridge with another conserved residue (lysine 484) in the relay helix. Enhanced sampling molecular dynamics simulations predict that the charge reversal mutation disrupts the E525-K484 salt-bridge, inducing conformations with a more flexible relay helix and a wide phosphate release tunnel. Our results highlight a highly conserved allosteric pathway associated with actin activation of the power stroke and phosphate release and suggest an important feature of the autoinhibited IHM is to prevent this region of myosin from interacting with actin. The ability of the E525K mutation to stabilize the IHM likely overrides the enhanced intrinsic motor properties, which may be key to triggering DCM pathogenesis.
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Affiliation(s)
- Skylar M. L. Bodt
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Jinghua Ge
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Wen Ma
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, California
| | - David V. Rasicci
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Rohini Desetty
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - J. Andrew McCammon
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, California
| | - Christopher M. Yengo
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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17
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Carrington G, Hau A, Kosta S, Dugdale HF, Muntoni F, D’Amico A, Van den Bergh P, Romero NB, Malfatti E, Vilchez JJ, Oldfors A, Pajusalu S, Õunap K, Giralt-Pujol M, Zanoteli E, Campbell KS, Iwamoto H, Peckham M, Ochala J. Human skeletal myopathy myosin mutations disrupt myosin head sequestration. JCI Insight 2023; 8:e172322. [PMID: 37788100 PMCID: PMC10721271 DOI: 10.1172/jci.insight.172322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 09/20/2023] [Indexed: 10/05/2023] Open
Abstract
Myosin heavy chains encoded by MYH7 and MYH2 are abundant in human skeletal muscle and important for muscle contraction. However, it is unclear how mutations in these genes disrupt myosin structure and function leading to skeletal muscle myopathies termed myosinopathies. Here, we used multiple approaches to analyze the effects of common MYH7 and MYH2 mutations in the light meromyosin (LMM) region of myosin. Analyses of expressed and purified MYH7 and MYH2 LMM mutant proteins combined with in silico modeling showed that myosin coiled coil structure and packing of filaments in vitro are commonly disrupted. Using muscle biopsies from patients and fluorescent ATP analog chase protocols to estimate the proportion of myosin heads that were super-relaxed, together with x-ray diffraction measurements to estimate myosin head order, we found that basal myosin ATP consumption was increased and the myosin super-relaxed state was decreased in vivo. In addition, myofiber mechanics experiments to investigate contractile function showed that myofiber contractility was not affected. These findings indicate that the structural remodeling associated with LMM mutations induces a pathogenic state in which formation of shutdown heads is impaired, thus increasing myosin head ATP demand in the filaments, rather than affecting contractility. These key findings will help design future therapies for myosinopathies.
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Affiliation(s)
- Glenn Carrington
- The Astbury Centre for Structural and Molecular Biology and
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Abbi Hau
- Centre of Human and Applied Physiological Sciences and
- Randall Centre for Cell and Molecular Biophysics, School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King’s College London, United Kingdom
| | - Sarah Kosta
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
| | - Hannah F. Dugdale
- Centre of Human and Applied Physiological Sciences and
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Francesco Muntoni
- UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- NIHR Biomedical Research Centre at Great Ormond Street Hospital, Great Ormond Street, London, United Kingdom
| | - Adele D’Amico
- Department of Neurosciences, Unit of Neuromuscular and Neurodegenerative Disorders, IRCCS Bambino Gesù Children’s Hospital, Rome, Italy
| | - Peter Van den Bergh
- Neuromuscular Reference Center, Neurology Department, University Hospital Saint-Luc, Brussels, Belgium
| | - Norma B. Romero
- Neuromuscular Morphology Unit, Institute of Myology, Myology Research Centre INSERM, Sorbonne University, Hôpital Pitié-Salpêtrière, Paris, France
| | - Edoardo Malfatti
- APHP, Centre de Référence de Pathologie Neuromusculaire Nord-Est-Ile-de-France, Henri Mondor Hospital, Inserm U955, Creteil, France
- U1179 UVSQ-INSERM Handicap Neuromuscular: Physiology, Biotherapy and Applied Pharmacology, UFR Simone Veil-Santé, Université Versailles Saint Quentin en Yvelines, Paris-Saclay, France
| | - Juan Jesus Vilchez
- Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain, Valencia, Spain
| | - Anders Oldfors
- Department of Laboratory Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Sander Pajusalu
- Genetics and Personalized Medicine Clinic, Tartu University Hospital, Tartu, Estonia
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Katrin Õunap
- Genetics and Personalized Medicine Clinic, Tartu University Hospital, Tartu, Estonia
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Marta Giralt-Pujol
- The Astbury Centre for Structural and Molecular Biology and
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Edmar Zanoteli
- Universidade de São Paulo, Hospital das Clínicas, Faculty of Medicine, Department of Neurology, São Paulo SP, Brazil
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Department of Neurology, São Paulo SP, Brazil
| | - Kenneth S. Campbell
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
- Division of Cardiovascular Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Hiroyuki Iwamoto
- SPring-8, Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - Michelle Peckham
- The Astbury Centre for Structural and Molecular Biology and
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Julien Ochala
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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18
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Dutta D, Nguyen V, Campbell KS, Padrón R, Craig R. Cryo-EM structure of the human cardiac myosin filament. Nature 2023; 623:853-862. [PMID: 37914935 PMCID: PMC10846670 DOI: 10.1038/s41586-023-06691-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 09/28/2023] [Indexed: 11/03/2023]
Abstract
Pumping of the heart is powered by filaments of the motor protein myosin that pull on actin filaments to generate cardiac contraction. In addition to myosin, the filaments contain cardiac myosin-binding protein C (cMyBP-C), which modulates contractility in response to physiological stimuli, and titin, which functions as a scaffold for filament assembly1. Myosin, cMyBP-C and titin are all subject to mutation, which can lead to heart failure. Despite the central importance of cardiac myosin filaments to life, their molecular structure has remained a mystery for 60 years2. Here we solve the structure of the main (cMyBP-C-containing) region of the human cardiac filament using cryo-electron microscopy. The reconstruction reveals the architecture of titin and cMyBP-C and shows how myosin's motor domains (heads) form three different types of motif (providing functional flexibility), which interact with each other and with titin and cMyBP-C to dictate filament architecture and function. The packing of myosin tails in the filament backbone is also resolved. The structure suggests how cMyBP-C helps to generate the cardiac super-relaxed state3; how titin and cMyBP-C may contribute to length-dependent activation4; and how mutations in myosin and cMyBP-C might disturb interactions, causing disease5,6. The reconstruction resolves past uncertainties and integrates previous data on cardiac muscle structure and function. It provides a new paradigm for interpreting structural, physiological and clinical observations, and for the design of potential therapeutic drugs.
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Affiliation(s)
- Debabrata Dutta
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
| | - Vu Nguyen
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Kenneth S Campbell
- Department of Physiology and Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY, USA
| | - Raúl Padrón
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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19
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Nag S, Gollapudi SK, Del Rio CL, Spudich JA, McDowell R. Mavacamten, a precision medicine for hypertrophic cardiomyopathy: From a motor protein to patients. SCIENCE ADVANCES 2023; 9:eabo7622. [PMID: 37506209 DOI: 10.1126/sciadv.abo7622] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 06/23/2023] [Indexed: 07/30/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder characterized by left ventricular hypertrophy, hyperdynamic contraction, and impaired relaxation of the heart. These functional derangements arise directly from altered sarcomeric function due to either mutations in genes encoding sarcomere proteins, or other defects such as abnormal energetics. Current treatment options do not directly address this causal biology but focus on surgical and extra-sarcomeric (sarcolemmal) pharmacological symptomatic relief. Mavacamten (formerly known as MYK-461), is a small molecule designed to regulate cardiac function at the sarcomere level by selectively but reversibly inhibiting the enzymatic activity of myosin, the fundamental motor of the sarcomere. This review summarizes the mechanism and translational progress of mavacamten from proteins to patients, describing how the mechanism of action and pharmacological characteristics, involving both systolic and diastolic effects, can directly target pathophysiological derangements within the cardiac sarcomere to improve cardiac structure and function in HCM. Mavacamten was approved by the Food and Drug Administration in April 2022 for the treatment of obstructive HCM and now goes by the commercial name of Camzyos. Full information about the risks, limitations, and side effects can be found at www.accessdata.fda.gov/drugsatfda_docs/label/2022/214998s000lbl.pdf.
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Affiliation(s)
- Suman Nag
- MyoKardia Inc., a wholly owned subsidiary of Bristol Myers Squibb, Brisbane, CA 94005, USA
| | - Sampath K Gollapudi
- MyoKardia Inc., a wholly owned subsidiary of Bristol Myers Squibb, Brisbane, CA 94005, USA
| | - Carlos L Del Rio
- MyoKardia Inc., a wholly owned subsidiary of Bristol Myers Squibb, Brisbane, CA 94005, USA
- Cardiac Consulting, 1630 S Delaware St. #56426, San Mateo, CA 94403, USA
| | | | - Robert McDowell
- MyoKardia Inc., a wholly owned subsidiary of Bristol Myers Squibb, Brisbane, CA 94005, USA
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