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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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2
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Chakraborti A, Tardiff JC, Schwartz SD. Myosin-Catalyzed ATP Hydrolysis in the Presence of Disease-Causing Mutations: Mavacamten as a Way to Repair Mechanism. J Phys Chem B 2024; 128:4716-4727. [PMID: 38708944 PMCID: PMC11103257 DOI: 10.1021/acs.jpcb.4c01601] [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] [Indexed: 05/07/2024]
Abstract
Hypertrophic cardiomyopathy is one of the most common forms of genetic cardiomyopathy. Mavacamten is a first-in-class myosin modulator that was identified via activity screening on the wild type, and it is FDA-approved for the treatment of obstructive hypertrophic cardiomyopathy (HCM). The drug selectively binds to the cardiac β-myosin, inhibiting myosin function to decrease cardiac contractility. Though the drug is thought to affect multiple steps of the myosin cross-bridge cycle, its detailed mechanism of action is still under investigation. Individual steps in the overall cross-bridge cycle must be queried to elucidate the full mechanism of action. In this study, we utilize the rare-event method of transition path sampling to generate reactive trajectories to gain insights into the action of the drug on the dynamics and rate of the ATP hydrolysis step for human cardiac β-myosin. We study three known HCM causative myosin mutations: R453C, P710R, and R712L to observe the effect of the drug on the alterations caused by these mutations in the chemical step. Since the crystal structure of the drug-bound myosin was not available at the time of this work, we created a model of the drug-bound system utilizing a molecular docking approach. We find a significant effect of the drug in one case, where the actual mechanism of the reaction is altered from the wild type by mutation. The drug restores both the rate of hydrolysis to the wildtype level and the mechanism of the reaction. This is a way to check the effect of the drug on untested mutations.
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Affiliation(s)
- Ananya Chakraborti
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Jil C Tardiff
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85724, United States
| | - Steven D Schwartz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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3
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Wang L, Bu T, Wu X, Li L, Sun F, Cheng CY. Motor proteins, spermatogenesis and testis function. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2024; 141:381-445. [PMID: 38960481 DOI: 10.1016/bs.apcsb.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The role of motor proteins in supporting intracellular transports of vesicles and organelles in mammalian cells has been known for decades. On the other hand, the function of motor proteins that support spermatogenesis is also well established since the deletion of motor protein genes leads to subfertility and/or infertility. Furthermore, mutations and genetic variations of motor protein genes affect fertility in men, but also a wide range of developmental defects in humans including multiple organs besides the testis. In this review, we seek to provide a summary of microtubule and actin-dependent motor proteins based on earlier and recent findings in the field. Since these two cytoskeletons are polarized structures, different motor proteins are being used to transport cargoes to different ends of these cytoskeletons. However, their involvement in germ cell transport across the blood-testis barrier (BTB) and the epithelium of the seminiferous tubules remains relatively unknown. It is based on recent findings in the field, we have provided a hypothetical model by which motor proteins are being used to support germ cell transport across the BTB and the seminiferous epithelium during the epithelial cycle of spermatogenesis. In our discussion, we have highlighted the areas of research that deserve attention to bridge the gap of research in relating the function of motor proteins to spermatogenesis.
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Affiliation(s)
- Lingling Wang
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China; Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Tiao Bu
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Xiaolong Wu
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Linxi Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Fei Sun
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - C Yan Cheng
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China; Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China.
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4
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Morales PN, Coons AN, Koopman AJ, Patel S, Chase PB, Parvatiyar MS, Pinto JR. Post-translational modifications of vertebrate striated muscle myosin heavy chains. Cytoskeleton (Hoboken) 2024. [PMID: 38587113 DOI: 10.1002/cm.21857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/06/2024] [Accepted: 03/25/2024] [Indexed: 04/09/2024]
Abstract
Post-translational modifications (PTMs) play a crucial role in regulating the function of many sarcomeric proteins, including myosin. Myosins comprise a family of motor proteins that play fundamental roles in cell motility in general and muscle contraction in particular. A myosin molecule consists of two myosin heavy chains (MyHCs) and two pairs of myosin light chains (MLCs); two MLCs are associated with the neck region of each MyHC's N-terminal head domain, while the two MyHC C-terminal tails form a coiled-coil that polymerizes with other MyHCs to form the thick filament backbone. Myosin undergoes extensive PTMs, and dysregulation of these PTMs may lead to abnormal muscle function and contribute to the development of myopathies and cardiovascular disorders. Recent studies have uncovered the significance of PTMs in regulating MyHC function and showed how these PTMs may provide additional modulation of contractile processes. Here, we discuss MyHC PTMs that have been biochemically and/or functionally studied in mammals' and rodents' striated muscle. We have identified hotspots or specific regions in three isoforms of myosin (MYH2, MYH6, and MYH7) where the prevalence of PTMs is more frequent and could potentially play a significant role in fine-tuning the activity of these proteins.
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Affiliation(s)
- Paula Nieto Morales
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida, USA
| | - Arianna N Coons
- Department of Biological Science, Florida State University, Tallahassee, Florida, USA
| | - Amelia J Koopman
- Department of Biological Science, Florida State University, Tallahassee, Florida, USA
| | - Sonu Patel
- Department of Health, Nutrition and Food Sciences, Florida State University, Tallahassee, Florida, USA
| | - P Bryant Chase
- Department of Biological Science, Florida State University, Tallahassee, Florida, USA
| | - Michelle S Parvatiyar
- Department of Health, Nutrition and Food Sciences, Florida State University, Tallahassee, Florida, USA
| | - Jose R Pinto
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida, USA
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5
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Blanc FEC, Houdusse A, Cecchini M. A weak coupling mechanism for the early steps of the recovery stroke of myosin VI: A free energy simulation and string method analysis. PLoS Comput Biol 2024; 20:e1012005. [PMID: 38662764 PMCID: PMC11086841 DOI: 10.1371/journal.pcbi.1012005] [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: 10/07/2023] [Revised: 05/10/2024] [Accepted: 03/15/2024] [Indexed: 05/12/2024] Open
Abstract
Myosin motors use the energy of ATP to produce force and directed movement on actin by a swing of the lever-arm. ATP is hydrolysed during the off-actin re-priming transition termed recovery stroke. To provide an understanding of chemo-mechanical transduction by myosin, it is critical to determine how the reverse swing of the lever-arm and ATP hydrolysis are coupled. Previous studies concluded that the recovery stroke of myosin II is initiated by closure of the Switch II loop in the nucleotide-binding site. Recently, we proposed that the recovery stroke of myosin VI starts with the spontaneous re-priming of the converter domain to a putative pre-transition state (PTS) intermediate that precedes Switch II closing and ATPase activation. Here, we investigate the transition from the pre-recovery, post-rigor (PR) state to PTS in myosin VI using geometric free energy simulations and the string method. First, our calculations rediscover the PTS state agnostically and show that it is accessible from PR via a low free energy transition path. Second, separate path calculations using the string method illuminate the mechanism of the PR to PTS transition with atomic resolution. In this mechanism, the initiating event is a large movement of the converter/lever-arm region that triggers rearrangements in the Relay-SH1 region and the formation of the kink in the Relay helix with no coupling to the active site. Analysis of the free-energy barriers along the path suggests that the converter-initiated mechanism is much faster than the one initiated by Switch II closure, which supports the biological relevance of PTS as a major on-pathway intermediate of the recovery stroke in myosin VI. Our analysis suggests that lever-arm re-priming and ATP hydrolysis are only weakly coupled, so that the myosin recovery stroke is initiated by thermal fluctuations and stabilised by nucleotide consumption via a ratchet-like mechanism.
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Affiliation(s)
- Florian E. C. Blanc
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, Strasbourg, France
- Structural Motility, Institut Curie, CNRS, UMR144, PSL Research University, Paris, France
| | - Anne Houdusse
- Structural Motility, Institut Curie, CNRS, UMR144, PSL Research University, Paris, France
| | - Marco Cecchini
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, Strasbourg, France
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Miyoshi T, Belyantseva IA, Sajeevadathan M, Friedman TB. Pathophysiology of human hearing loss associated with variants in myosins. Front Physiol 2024; 15:1374901. [PMID: 38562617 PMCID: PMC10982375 DOI: 10.3389/fphys.2024.1374901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 02/21/2024] [Indexed: 04/04/2024] Open
Abstract
Deleterious variants of more than one hundred genes are associated with hearing loss including MYO3A, MYO6, MYO7A and MYO15A and two conventional myosins MYH9 and MYH14. Variants of MYO7A also manifest as Usher syndrome associated with dysfunction of the retina and vestibule as well as hearing loss. While the functions of MYH9 and MYH14 in the inner ear are debated, MYO3A, MYO6, MYO7A and MYO15A are expressed in inner ear hair cells along with class-I myosin MYO1C and are essential for developing and maintaining functional stereocilia on the apical surface of hair cells. Stereocilia are large, cylindrical, actin-rich protrusions functioning as biological mechanosensors to detect sound, acceleration and posture. The rigidity of stereocilia is sustained by highly crosslinked unidirectionally-oriented F-actin, which also provides a scaffold for various proteins including unconventional myosins and their cargo. Typical myosin molecules consist of an ATPase head motor domain to transmit forces to F-actin, a neck containing IQ-motifs that bind regulatory light chains and a tail region with motifs recognizing partners. Instead of long coiled-coil domains characterizing conventional myosins, the tails of unconventional myosins have various motifs to anchor or transport proteins and phospholipids along the F-actin core of a stereocilium. For these myosins, decades of studies have elucidated their biochemical properties, interacting partners in hair cells and variants associated with hearing loss. However, less is known about how myosins traffic in a stereocilium using their motor function, and how each variant correlates with a clinical condition including the severity and onset of hearing loss, mode of inheritance and presence of symptoms other than hearing loss. Here, we cover the domain structures and functions of myosins associated with hearing loss together with advances, open questions about trafficking of myosins in stereocilia and correlations between hundreds of variants in myosins annotated in ClinVar and the corresponding deafness phenotypes.
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Affiliation(s)
- Takushi Miyoshi
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States
- Division of Molecular and Integrative Physiology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, IL, United States
| | - Inna A. Belyantseva
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States
| | - Mrudhula Sajeevadathan
- Division of Molecular and Integrative Physiology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, IL, United States
| | - Thomas B. Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States
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Liu C, Karabina A, Meller A, Bhattacharjee A, Agostino CJ, Bowman GR, Ruppel KM, Spudich JA, Leinwand LA. Homologous mutations in human β, embryonic, and perinatal muscle myosins have divergent effects on molecular power generation. Proc Natl Acad Sci U S A 2024; 121:e2315472121. [PMID: 38377203 PMCID: PMC10907259 DOI: 10.1073/pnas.2315472121] [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: 09/24/2023] [Accepted: 01/12/2024] [Indexed: 02/22/2024] Open
Abstract
Mutations at a highly conserved homologous residue in three closely related muscle myosins cause three distinct diseases involving muscle defects: R671C in β-cardiac myosin causes hypertrophic cardiomyopathy, R672C and R672H in embryonic skeletal myosin cause Freeman-Sheldon syndrome, and R674Q in perinatal skeletal myosin causes trismus-pseudocamptodactyly syndrome. It is not known whether their effects at the molecular level are similar to one another or correlate with disease phenotype and severity. To this end, we investigated the effects of the homologous mutations on key factors of molecular power production using recombinantly expressed human β, embryonic, and perinatal myosin subfragment-1. We found large effects in the developmental myosins but minimal effects in β myosin, and magnitude of changes correlated partially with clinical severity. The mutations in the developmental myosins dramatically decreased the step size and load-sensitive actin-detachment rate of single molecules measured by optical tweezers, in addition to decreasing overall enzymatic (ATPase) cycle rate. In contrast, the only measured effect of R671C in β myosin was a larger step size. Our measurements of step size and bound times predicted velocities consistent with those measured in an in vitro motility assay. Finally, molecular dynamics simulations predicted that the arginine to cysteine mutation in embryonic, but not β, myosin may reduce pre-powerstroke lever arm priming and ADP pocket opening, providing a possible structural mechanism consistent with the experimental observations. This paper presents direct comparisons of homologous mutations in several different myosin isoforms, whose divergent functional effects are a testament to myosin's highly allosteric nature.
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Affiliation(s)
- Chao Liu
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA94305
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA94305
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA94550
| | - Anastasia Karabina
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO80309
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO80309
- Kainomyx, Inc., Palo Alto, CA94304
| | - Artur Meller
- Department of Biochemistry and Biophysics, Washington University in St. Louis, St. Louis, MO63110
- Medical Scientist Training Program, Washington University in St. Louis, St. Louis, MO63110
| | - Ayan Bhattacharjee
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - Colby J. Agostino
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - Greg R. Bowman
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - Kathleen M. Ruppel
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA94305
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA94305
- Kainomyx, Inc., Palo Alto, CA94304
| | - James A. Spudich
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA94305
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA94305
- Kainomyx, Inc., Palo Alto, CA94304
| | - Leslie A. Leinwand
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO80309
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO80309
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8
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Childers MC, Regnier M. Atomistic Simulations of Sarcomere Proteins. Methods Mol Biol 2024; 2735:27-41. [PMID: 38038842 DOI: 10.1007/978-1-0716-3527-8_3] [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: 12/02/2023]
Abstract
Concerted atomic motions are requisite for sarcomere protein function and may become disrupted in HCM pathologies. Computational approaches such as molecular dynamics simulation can resolve such dynamics with unrivalled spatial and temporal resolution. This chapter describes methods to model structural and dynamical changes in biomolecules with HCM-associated perturbations.
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Affiliation(s)
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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Bao Y, Xu Y, Jia F, Li M, Xu R, Zhang F, Guo J. Allosteric inhibition of myosin by phenamacril: a synergistic mechanism revealed by computational and experimental approaches. PEST MANAGEMENT SCIENCE 2023; 79:4977-4989. [PMID: 37540764 DOI: 10.1002/ps.7699] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 07/29/2023] [Accepted: 08/04/2023] [Indexed: 08/06/2023]
Abstract
BACKGROUND Myosin plays a crucial role in cellular processes, while its dysfunction can lead to organismal malfunction. Phenamacril (PHA), a highly species-specific and non-competitive inhibitor of myosin I (FgMyoI) from Fusarium graminearum, has been identified as an effective fungicide for controlling plant diseases caused by partial Fusarium pathogens, such as wheat scab and rice bakanae. However, the molecular basis of its action is still unclear. RESULTS This study used multiple computational approaches first to elucidate the allosteric inhibition mechanism of FgMyoI by PHA at the atomistic level. The results indicated the increase of adenosine triphosphate (ATP) binding affinity upon PHA binding, which might impede the release of hydrolysis products. Furthermore, simulations revealed a broadened outer cleft and a significantly more flexible interface for actin binding, accompanied by a decrease in signaling transduction from the catalytic center to the actin-binding interface. These various effects might work together to disrupt the actomyosin cycle and hinder the ability of motor to generate force. Our experimental results further confirmed that PHA reduces the enzymatic activity of myosin and its binding with actin. CONCLUSION Therefore, our findings demonstrated that PHA might suppress the function of myosin through a synergistic mechanism, providing new insights into myosin allostery and offering new avenues for drug/fungicide discovery targeting myosin. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Yiqiong Bao
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yan Xu
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Fangying Jia
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Mengrong Li
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Ran Xu
- Centre for Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
| | - Feng Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jingjing Guo
- Centre for Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
- Engineering Research Centre of Applied Technology on Machine Translation and Artificial Intelligence, Macao Polytechnic University, Macao, China
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10
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Lee S, Jo K, Jeong SKC, Choi YS, Jung S. High-pressure processing of beef increased the in vitro protein digestibility in an infant digestion model. Meat Sci 2023; 205:109318. [PMID: 37647738 DOI: 10.1016/j.meatsci.2023.109318] [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: 06/09/2023] [Revised: 08/10/2023] [Accepted: 08/18/2023] [Indexed: 09/01/2023]
Abstract
Beef is an ideal protein source for use as a complementary food in infants. Considering the limited protein-digesting capacity of infants, it is required to enhance protein digestibility while minimizing the deterioration of beef quality. Thus, this study aimed to determine the effects of high-pressure processing (HPP) on the physicochemical properties and in vitro digestibility of beef proteins in an infant digestion model. HPP at 200 and 300 MPa decreased the tryptophan fluorescence intensity of the myosin and actin fractions relative to that at 0.1 MPa (P < 0.05). Compared to treatment at 0.1 and 100 MPa, HPP at 300 MPa decreased α-helix and β-turn contents in the myosin and actin fractions (P < 0.05), whilst increasing the β-sheet content (P < 0.05). Beef actomyosin content decreased (P < 0.05) during HPP at 200 and 300 MPa (c.f., 0.1 and 100 MPa). After in vitro digestion of beef, HPP at 200 and 300 MPa increased the α-amino group content and the abundance of proteins below 3 kDa in the digesta (P < 0.05). However, due to the considerable lipid oxidation at 300 MPa, HPP at 200 MPa is ideal for improving the protein digestibility of beef when incorporated into complementary foods for infants.
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Affiliation(s)
- Seonmin Lee
- Division of Animal and Dairy Science, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Kyung Jo
- Division of Animal and Dairy Science, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Seul-Ki-Chan Jeong
- Division of Animal and Dairy Science, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Yun-Sang Choi
- Research Group of Food Processing, Korea Food Research Institute, Wanju 55365, Republic of Korea.
| | - Samooel Jung
- Division of Animal and Dairy Science, Chungnam National University, Daejeon 34134, Republic of Korea.
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11
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Wang C, Ding J, Wei Q, Du S, Gong X, Chew TG. Mechanosensitive accumulation of non-muscle myosin IIB during mitosis requires its translocation activity. iScience 2023; 26:107773. [PMID: 37720093 PMCID: PMC10504539 DOI: 10.1016/j.isci.2023.107773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/02/2023] [Accepted: 08/26/2023] [Indexed: 09/19/2023] Open
Abstract
Non-muscle myosin II (NMII) is a force-generating mechanosensitive enzyme that responds to mechanical forces. NMIIs mechanoaccumulate at the cell cortex in response to mechanical forces. It is essential for cells to mechanically adapt to the physical environment, failure of which results in mitotic defects when dividing in confined environment. Much less is known about how NMII mechanoaccumulation is regulated during mitosis. We show that mitotic cells respond to compressive stress by promoting accumulation of active RhoA at the cell cortex as in interphase cells. RhoA mechanoresponse during mitosis activates and stabilizes NMIIB via ROCK signaling, leading to NMIIB mechanoaccumulation at the cell cortex. Using disease-related myosin II mutations, we found that NMIIB mechanoaccumulation requires its motor activity that translocates actin filaments, but not just its actin-binding function. Thus, the motor activity coordinates structural movement and nucleotide state changes to fine-tune actin-binding affinity optimal for NMIIs to generate and respond to forces.
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Affiliation(s)
- Chao Wang
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Hangzhou 310058, China
- The Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining 314400, China
| | - Jingjing Ding
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Hangzhou 310058, China
- The Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining 314400, China
| | - Qiaodong Wei
- Department of Engineering Mechanics, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shoukang Du
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Hangzhou 310058, China
- The Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining 314400, China
| | - Xiaobo Gong
- Department of Engineering Mechanics, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ting Gang Chew
- Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Hangzhou 310058, China
- The Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining 314400, China
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12
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Choi J, Holmes JB, Campbell KS, Stelzer JE. Effect of the Novel Myotrope Danicamtiv on Cross-Bridge Behavior in Human Myocardium. J Am Heart Assoc 2023; 12:e030682. [PMID: 37804193 PMCID: PMC10757519 DOI: 10.1161/jaha.123.030682] [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: 04/19/2023] [Accepted: 09/13/2023] [Indexed: 10/09/2023]
Abstract
Background Omecamtiv mecarbil (OM) and danicamtiv both increase myocardial force output by selectively activating myosin within the cardiac sarcomere. Enhanced force generation is presumably due to an increase in the total number of myosin heads bound to the actin filament; however, detailed comparisons of the molecular mechanisms of OM and danicamtiv are lacking. Methods and Results The effect of OM and danicamtiv on Ca2+ sensitivity of force generation was analyzed by exposing chemically skinned myocardial samples to a series of increasing Ca2+ solutions. The results showed that OM significantly increased Ca2+ sensitivity of force generation, whereas danicamtiv showed similar Ca2+ sensitivity of force generation to untreated preparations. A direct comparison of OM and danicamtiv on dynamic cross-bridge behavior was performed at a concentration that produced a similar force increase when normalized to predrug levels at submaximal force (pCa 6.1). Both OM and danicamtiv-treated groups slowed the rates of cross-bridge detachment from the strongly bound state and cross-bridge recruitment into the force-producing state. Notably, the significant OM-induced prolongation in the time to reach force relaxation and subsequent commencement of force generation following rapid stretch was dramatically reduced in danicamtiv-treated myocardium. Conclusions This is the first study to directly compare the effects of OM and danicamtiv on cross-bridge kinetics. At a similar level of force enhancement, danicamtiv had a less pronounced effect on the slowing of cross-bridge kinetics and, therefore, may provide a similar improvement in systolic function as OM without excessively prolonging systolic ejection time and slowing cardiac relaxation facilitating diastolic filling at the whole-organ level.
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Affiliation(s)
- Joohee Choi
- Department of Physiology and Biophysics, School of MedicineCase Western Reserve UniversityClevelandOH
| | - Joshua B. Holmes
- Department of Physiology and Biophysics, School of MedicineCase Western Reserve UniversityClevelandOH
| | - Kenneth S. Campbell
- Division of Cardiovascular MedicineUniversity of KentuckyLexingtonKY
- Department of PhysiologyUniversity of KentuckyLexingtonKY
| | - Julian E. Stelzer
- Department of Physiology and Biophysics, School of MedicineCase Western Reserve UniversityClevelandOH
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13
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Hojjatian A, Rastegarpouyani H, Taylor DW, Taylor KA. Novel ADP State Found in Smooth Muscle Heavy Meromyosin by CryoEM. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:912-914. [PMID: 37613403 DOI: 10.1093/micmic/ozad067.452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Alimohammad Hojjatian
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
| | - Hosna Rastegarpouyani
- Department of Biological Sciences, Florida State University, Tallahassee, FL, United States
| | - Dianne W Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
| | - Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
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14
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Liu C, Karabina A, Meller A, Bhattacharjee A, Agostino CJ, Bowman GR, Ruppel KM, Spudich JA, Leinwand LA. Homologous mutations in β, embryonic, and perinatal muscle myosins have divergent effects on molecular power generation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.02.547385. [PMID: 37425764 PMCID: PMC10327197 DOI: 10.1101/2023.07.02.547385] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Mutations at a highly conserved homologous residue in three closely related muscle myosins cause three distinct diseases involving muscle defects: R671C in β -cardiac myosin causes hypertrophic cardiomyopathy, R672C and R672H in embryonic skeletal myosin cause Freeman Sheldon syndrome, and R674Q in perinatal skeletal myosin causes trismus-pseudocamptodactyly syndrome. It is not known if their effects at the molecular level are similar to one another or correlate with disease phenotype and severity. To this end, we investigated the effects of the homologous mutations on key factors of molecular power production using recombinantly expressed human β , embryonic, and perinatal myosin subfragment-1. We found large effects in the developmental myosins, with the most dramatic in perinatal, but minimal effects in β myosin, and magnitude of changes correlated partially with clinical severity. The mutations in the developmental myosins dramatically decreased the step size and load-sensitive actin-detachment rate of single molecules measured by optical tweezers, in addition to decreasing ATPase cycle rate. In contrast, the only measured effect of R671C in β myosin was a larger step size. Our measurements of step size and bound times predicted velocities consistent with those measured in an in vitro motility assay. Finally, molecular dynamics simulations predicted that the arginine to cysteine mutation in embryonic, but not β , myosin may reduce pre-powerstroke lever arm priming and ADP pocket opening, providing a possible structural mechanism consistent with the experimental observations. This paper presents the first direct comparisons of homologous mutations in several different myosin isoforms, whose divergent functional effects are yet another testament to myosin's highly allosteric nature.
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Affiliation(s)
- Chao Liu
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Anastasia Karabina
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303
- Kainomyx, Inc., Palo Alto, CA 94304
| | - Artur Meller
- Department of Biochemistry and Biophysics, Washington University in St. Louis, St. Louis, MO 63110
- Medical Scientist Training Program, Washington University in St. Louis, St. Louis, MO 63110
| | - Ayan Bhattacharjee
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Colby J Agostino
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Greg R Bowman
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Kathleen M Ruppel
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305
- Kainomyx, Inc., Palo Alto, CA 94304
| | - James A Spudich
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305
- Kainomyx, Inc., Palo Alto, CA 94304
| | - Leslie A Leinwand
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80303
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15
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Marang C, Scott B, Chambers J, Gunther LK, Yengo CM, Debold EP. A mutation in switch I alters the load-dependent kinetics of myosin Va. Nat Commun 2023; 14:3137. [PMID: 37253724 PMCID: PMC10229639 DOI: 10.1038/s41467-023-38535-0] [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: 09/19/2022] [Accepted: 05/05/2023] [Indexed: 06/01/2023] Open
Abstract
Myosin Va is the molecular motor that drives intracellular vesicular transport, powered by the transduction of chemical energy from ATP into mechanical work. The coupling of the powerstroke and phosphate (Pi) release is key to understanding the transduction process, and crucial details of this process remain unclear. Therefore, we determined the effect of elevated Pi on the force-generating capacity of a mini-ensemble of myosin Va S1 (WT) in a laser trap assay. By increasing the stiffness of the laser trap we determined the effect of increasing resistive loads on the rate of Pi-induced detachment from actin, and quantified this effect using the Bell approximation. We observed that WT myosin generated higher forces and larger displacements at the higher laser trap stiffnesses in the presence of 30 mM Pi, but binding event lifetimes decreased dramatically, which is most consistent with the powerstroke preceding the release of Pi from the active site. Repeating these experiments using a construct with a mutation in switch I of the active site (S217A) caused a seven-fold increase in the load-dependence of the Pi-induced detachment rate, suggesting that the S217A region of switch I may help mediate the load-dependence of Pi-rebinding.
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Affiliation(s)
- Christopher Marang
- Department of Kinesiology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Brent Scott
- Department of Kinesiology, University of Massachusetts, Amherst, MA, 01003, USA
| | - James Chambers
- Institute for Applied Life Sciences, University of Massachusetts, Amherst, MA, 01003, USA
| | - Laura K Gunther
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, 17033, USA
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, 17033, USA
| | - Edward P Debold
- Department of Kinesiology, University of Massachusetts, Amherst, MA, 01003, USA.
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16
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Kubař T, Elstner M, Cui Q. Hybrid Quantum Mechanical/Molecular Mechanical Methods For Studying Energy Transduction in Biomolecular Machines. Annu Rev Biophys 2023; 52:525-551. [PMID: 36791746 PMCID: PMC10810093 DOI: 10.1146/annurev-biophys-111622-091140] [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: 02/17/2023]
Abstract
Hybrid quantum mechanical/molecular mechanical (QM/MM) methods have become indispensable tools for the study of biomolecules. In this article, we briefly review the basic methodological details of QM/MM approaches and discuss their applications to various energy transduction problems in biomolecular machines, such as long-range proton transports, fast electron transfers, and mechanochemical coupling. We highlight the particular importance for these applications of balancing computational efficiency and accuracy. Using several recent examples, we illustrate the value and limitations of QM/MM methodologies for both ground and excited states, as well as strategies for calibrating them in specific applications. We conclude with brief comments on several areas that can benefit from further efforts to make QM/MM analyses more quantitative and applicable to increasingly complex biological problems.
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Affiliation(s)
- T Kubař
- Institute of Physical Chemistry, Karlsruhe Institute of Technology, Karlsruhe, Germany;
| | - M Elstner
- Institute of Physical Chemistry, Karlsruhe Institute of Technology, Karlsruhe, Germany;
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology, Karlsruhe, Germany;
| | - Q Cui
- Department of Chemistry, Boston University, Boston, Massachusetts, USA;
- Department of Physics, Boston University, Boston, Massachusetts, USA
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
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17
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Pollard LW, Coscia SM, Rebowski G, Palmer NJ, Holzbaur ELF, Dominguez R, Ostap EM. Ensembles of human myosin-19 bound to calmodulin and regulatory light chain RLC12B drive multimicron transport. J Biol Chem 2023; 299:102906. [PMID: 36642185 PMCID: PMC9929473 DOI: 10.1016/j.jbc.2023.102906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 01/15/2023] Open
Abstract
Myosin-19 (Myo19) controls the size, morphology, and distribution of mitochondria, but the underlying role of Myo19 motor activity is unknown. Complicating mechanistic in vitro studies, the identity of the light chains (LCs) of Myo19 remains unsettled. Here, we show by coimmunoprecipitation, reconstitution, and proteomics that the three IQ motifs of human Myo19 expressed in Expi293 human cells bind regulatory light chain (RLC12B) and calmodulin (CaM). We demonstrate that overexpression of Myo19 in HeLa cells enhances the recruitment of both Myo19 and RLC12B to mitochondria, suggesting cellular association of RLC12B with the motor. Further experiments revealed that RLC12B binds IQ2 and is flanked by two CaM molecules. In vitro, we observed that the maximal speed (∼350 nm/s) occurs when Myo19 is supplemented with CaM, but not RLC12B, suggesting maximal motility requires binding of CaM to IQ-1 and IQ-3. The addition of calcium slowed actin gliding (∼200 nm/s) without an apparent effect on CaM affinity. Furthermore, we show that small ensembles of Myo19 motors attached to quantum dots can undergo processive runs over several microns, and that calcium reduces the attachment frequency and run length of Myo19. Together, our data are consistent with a model where a few single-headed Myo19 molecules attached to a mitochondrion can sustain prolonged motile associations with actin in a CaM- and calcium-dependent manner. Based on these properties, we propose that Myo19 can function in mitochondria transport along actin filaments, tension generation on multiple randomly oriented filaments, and/or pushing against branched actin networks assembled near the membrane surface.
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Affiliation(s)
- Luther W Pollard
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Stephen M Coscia
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Cell and Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Grzegorz Rebowski
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Nicholas J Palmer
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Roberto Dominguez
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
| | - E Michael Ostap
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
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18
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Chakraborti A, Tardiff JC, Schwartz SD. Insights into the Mechanism of the Cardiac Drug Omecamtiv Mecarbil─A Computational Study. J Phys Chem B 2022; 126:10069-10082. [PMID: 36448224 PMCID: PMC9830884 DOI: 10.1021/acs.jpcb.2c06679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Omecamtiv mecarbil (OM) is a positive inotrope that is thought to bind directly to an allosteric site of the β-cardiac myosin. The drug is under investigation for the treatment of systolic heart failure. The drug is classified as a cardiac myosin modulator and has been observed to affect multiple vital steps of the cross-bridge cycle including the recovery stroke and the chemical step. We explored the free-energy surface of the recovery stroke of the human cardiac β-myosin in the presence of OM to determine its influence on this process. We also investigated the effects of OM on the recovery stroke in the presence of genetic cardiomyopathic mutations R712L, F764L, and P710R using metadynamics. We also utilized the method of transition path sampling to generate an unbiased ensemble of reactive trajectories for the ATP hydrolysis step in the presence of OM that were able to provide insight into the differences observed due to OM in the dynamics and mechanism of the decomposition of ATP to ADP and HPO42-, a central part of the power generation in cardiac muscle. We studied chemistry in the presence of the same three mutations to further elucidate the effect of OM, and its use in the treatment of cardiac disease.
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Affiliation(s)
- Ananya Chakraborti
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Jil C. Tardiff
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85724, United States
| | - Steven D. Schwartz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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19
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Zhao Y, Ding S, Todoh M. Validate the force-velocity relation of the Hill's muscle model from a molecular perspective. Front Bioeng Biotechnol 2022; 10:1006571. [PMID: 36312549 PMCID: PMC9614041 DOI: 10.3389/fbioe.2022.1006571] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/30/2022] [Indexed: 07/30/2023] Open
Affiliation(s)
- Yongkun Zhao
- Division of Human Mechanical Systems and Design, Graduate School of Engineering, Hokkaido University, Sapporo, Japan
- Division of Bioengineering, Graduate School of Engineering Science, Osaka University, Osaka, Japan
| | - Shihang Ding
- Division of Bioengineering, Graduate School of Engineering Science, Osaka University, Osaka, Japan
| | - Masahiro Todoh
- Division of Mechanical and Aerospace Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
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20
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Kawana M, Spudich JA, Ruppel KM. Hypertrophic cardiomyopathy: Mutations to mechanisms to therapies. Front Physiol 2022; 13:975076. [PMID: 36225299 PMCID: PMC9548533 DOI: 10.3389/fphys.2022.975076] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 08/22/2022] [Indexed: 01/10/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) affects more than 1 in 500 people in the general population with an extensive burden of morbidity in the form of arrhythmia, heart failure, and sudden death. More than 25 years since the discovery of the genetic underpinnings of HCM, the field has unveiled significant insights into the primary effects of these genetic mutations, especially for the myosin heavy chain gene, which is one of the most commonly mutated genes. Our group has studied the molecular effects of HCM mutations on human β-cardiac myosin heavy chain using state-of-the-art biochemical and biophysical tools for the past 10 years, combining insights from clinical genetics and structural analyses of cardiac myosin. The overarching hypothesis is that HCM-causing mutations in sarcomere proteins cause hypercontractility at the sarcomere level, and we have shown that an increase in the number of myosin molecules available for interaction with actin is a primary driver. Recently, two pharmaceutical companies have developed small molecule inhibitors of human cardiac myosin to counteract the molecular consequences of HCM pathogenesis. One of these inhibitors (mavacamten) has recently been approved by the FDA after completing a successful phase III trial in HCM patients, and the other (aficamten) is currently being evaluated in a phase III trial. Myosin inhibitors will be the first class of medication used to treat HCM that has both robust clinical trial evidence of efficacy and that targets the fundamental mechanism of HCM pathogenesis. The success of myosin inhibitors in HCM opens the door to finding other new drugs that target the sarcomere directly, as we learn more about the genetics and fundamental mechanisms of this disease.
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Affiliation(s)
- Masataka Kawana
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, United States,Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, United States
| | - James A. Spudich
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, United States
| | - Kathleen M. Ruppel
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, United States,*Correspondence: Kathleen M. Ruppel,
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21
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Abstract
The global burden caused by cardiovascular disease is substantial, with heart disease representing the most common cause of death around the world. There remains a need to develop better mechanistic models of cardiac function in order to combat this health concern. Heart rhythm disorders, or arrhythmias, are one particular type of disease which has been amenable to quantitative investigation. Here we review the application of quantitative methodologies to explore dynamical questions pertaining to arrhythmias. We begin by describing single-cell models of cardiac myocytes, from which two and three dimensional models can be constructed. Special focus is placed on results relating to pattern formation across these spatially-distributed systems, especially the formation of spiral waves of activation. Next, we discuss mechanisms which can lead to the initiation of arrhythmias, focusing on the dynamical state of spatially discordant alternans, and outline proposed mechanisms perpetuating arrhythmias such as fibrillation. We then review experimental and clinical results related to the spatio-temporal mapping of heart rhythm disorders. Finally, we describe treatment options for heart rhythm disorders and demonstrate how statistical physics tools can provide insights into the dynamics of heart rhythm disorders.
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Affiliation(s)
- Wouter-Jan Rappel
- Department of Physics, University of California San Diego, La Jolla, CA 92037
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22
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Kronert WA, Hsu KH, Madan A, Sarsoza F, Cammarato A, Bernstein SI. Myosin Transducer Inter-Strand Communication Is Critical for Normal ATPase Activity and Myofibril Structure. BIOLOGY 2022; 11:biology11081137. [PMID: 36009764 PMCID: PMC9404822 DOI: 10.3390/biology11081137] [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: 06/24/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 02/07/2023]
Abstract
The R249Q mutation in human β-cardiac myosin results in hypertrophic cardiomyopathy. We previously showed that inserting this mutation into Drosophila melanogaster indirect flight muscle myosin yields mechanical and locomotory defects. Here, we use transgenic Drosophila mutants to demonstrate that residue R249 serves as a critical communication link within myosin that controls both ATPase activity and myofibril integrity. R249 is located on a β-strand of the central transducer of myosin, and our molecular modeling shows that it interacts via a salt bridge with D262 on the adjacent β-strand. We find that disrupting this interaction via R249Q, R249D or D262R mutations reduces basal and actin-activated ATPase activity, actin in vitro motility and flight muscle function. Further, the R249D mutation dramatically affects myofibril assembly, yielding abnormalities in sarcomere lengths, increased Z-line thickness and split myofibrils. These defects are exacerbated during aging. Re-establishing the β-strand interaction via a R249D/D262R double mutation restores both basal ATPase activity and myofibril assembly, indicating that these properties are dependent upon transducer inter-strand communication. Thus, the transducer plays an important role in myosin function and myofibril architecture.
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Affiliation(s)
- William A. Kronert
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.A.K.); (K.H.H.); (F.S.)
| | - Karen H. Hsu
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.A.K.); (K.H.H.); (F.S.)
| | - Aditi Madan
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205, USA; (A.M.); (A.C.)
| | - Floyd Sarsoza
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.A.K.); (K.H.H.); (F.S.)
| | - Anthony Cammarato
- Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD 21205, USA; (A.M.); (A.C.)
| | - Sanford I. Bernstein
- Department of Biology, Molecular Biology Institute, Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.A.K.); (K.H.H.); (F.S.)
- Correspondence:
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23
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Angelidis A, Vandenboom R. The effect of muscle length on post-tetanic potentiation of C57BL/6 and skMLCK -/- mouse EDL muscles. J Muscle Res Cell Motil 2022; 43:99-111. [PMID: 35771335 DOI: 10.1007/s10974-022-09620-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/12/2022] [Indexed: 11/25/2022]
Abstract
Post-tetanic potentiation of fast-twitch skeletal muscle is dependent on muscle length, with greater potentiation observed at shorter compared to longer lengths. The structural effects of the primary potentiation mechanism, phosphorylation of the regulatory light chain (RLC) of myosin, are thought to explain this relationship. The purpose of these experiments was to determine whether the length-dependence of potentiation would be attenuated in the absence of RLC phosphorylation. To this end, we compared isometric twitch potentiation of mouse extensor digitorum longus (EDL) muscles with (wildtype, WT) and without (skeletal myosin light chain kinase knockout, skMLCK-/-) phosphorylation. Force was measured at five muscle lengths (0.90 Lo, 0.95 Lo, Lo, 1.05 Lo, 1.10 Lo, where Lo refers to optimal length) prior to and following a tetanic train. In accordance with prior findings, potentiation was dependent on muscle length, with greater values observed at short (e.g., 44.3 ± 4.6% for WT, 33.5 ± 6.2% for skMLCK-/-, at 0.90 Lo) compared to long lengths (e.g., 16.9 ± 1.3% for WT, 9.1 ± 1.8% for skMLCK-/-, at 1.10 Lo) in both genotypes. WT muscles displayed greater potentiation compared to their skMLCK-/- counterparts across lengths (e.g., 16.9 ± 1.6% vs 7.3 ± 1.5% at Lo). However, the relationship between potentiation and muscle length was not different between genotypes. Thus, the alternative mechanisms of potentiation, present in the skMLCK-/- EDL, display a length-dependence of post-tetanic potentiation similar to RLC phosphorylation-dominant potentiation. Additional mechanisms may be required to explain the length-dependence of potentiation.
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Affiliation(s)
- Angelos Angelidis
- Department of Kinesiology, Centre for Bone and Muscle Health, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada.
| | - Rene Vandenboom
- Department of Kinesiology, Centre for Bone and Muscle Health, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
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24
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Adler NS, Cababie LA, Sarto C, Cavasotto CN, Gebhard L, Estrin D, Gamarnik A, Arrar M, Kaufman S. Insights into the product release mechanism of dengue virus NS3 helicase. Nucleic Acids Res 2022; 50:6968-6979. [PMID: 35736223 PMCID: PMC9262617 DOI: 10.1093/nar/gkac473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/11/2022] [Accepted: 05/19/2022] [Indexed: 12/24/2022] Open
Abstract
The non-structural protein 3 helicase (NS3h) is a multifunctional protein that is critical in RNA replication and other stages in the flavivirus life cycle. NS3h uses energy from ATP hydrolysis to translocate along single stranded nucleic acid and to unwind double stranded RNA. Here we present a detailed mechanistic analysis of the product release stage in the catalytic cycle of the dengue virus (DENV) NS3h. This study is based on a combined experimental and computational approach of product-inhibition studies and free energy calculations. Our results support a model in which the catalytic cycle of ATP hydrolysis proceeds through an ordered sequential mechanism that includes a ternary complex intermediate (NS3h-Pi-ADP), which evolves releasing the first product, phosphate (Pi), and subsequently ADP. Our results indicate that in the product release stage of the DENV NS3h a novel open-loop conformation plays an important role that may be conserved in NS3 proteins of other flaviviruses as well.
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Affiliation(s)
| | | | - Carolina Sarto
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica, Analítica y Química Física, Buenos Aires, C1428EGA Argentina,CONICET-Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, C1428EGA Argentina
| | - Claudio N Cavasotto
- CONICET-Universidad Austral, Instituto de Investigaciones en Medicina Traslacional (IIMT), Pilar, Buenos Aires, B1630FHB Argentina,Universidad Austral, Facultad de Ciencias Biomédicas, and Facultad de Ingeniería, Pilar, Buenos Aires, B1630FHB Argentina,Universidad Austral, Austral Institute for Applied Artificial Intelligence, Pilar, Buenos Aires, B1630FHB Argentina
| | - Leopoldo G Gebhard
- CONICET-Universidad Nacional de Quilmes, Departamento de Ciencia y Tecnología, Bernal, Buenos Aires, B1876 Argentina
| | - Darío A Estrin
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica, Analítica y Química Física, Buenos Aires, C1428EGA Argentina,CONICET-Universidad de Buenos Aires, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Buenos Aires, C1428EGA Argentina
| | - Andrea V Gamarnik
- Fundación Instituto Leloir- CONICET, Buenos Aires, C1405BWE Argentina
| | | | - Sergio B Kaufman
- To whom correspondence should be addressed. Tel: +5411 4964 8289 ext 106; Fax: +5411 4962 5457;
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25
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Mondino S, San Martin F, Buschiazzo A. 3D cryo-electron microscopic imaging of bacterial flagella: novel structural and mechanistic insights into cell motility. J Biol Chem 2022; 298:102105. [PMID: 35671822 PMCID: PMC9254593 DOI: 10.1016/j.jbc.2022.102105] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 10/26/2022] Open
Abstract
Bacterial flagella are nanomachines that enable cells to move at high speeds. Comprising ≳25 different types of proteins, the flagellum is a large supramolecular assembly organized into three widely conserved substructures: a basal body including the rotary motor, a connecting hook, and a long filament. The whole flagellum from Escherichia coli weighs ∼20 MDa, without considering its filament portion, which is by itself a ∼1.6 GDa structure arranged as a multimer of ∼30,000 flagellin protomers. Breakthroughs regarding flagellar structure and function have been achieved in the last few years, mainly due to the revolutionary improvements in 3D cryo-electron microscopy methods. This review discusses novel structures and mechanistic insights derived from such high-resolution studies, advancing our understanding of each one of the three major flagellar segments. The rotation mechanism of the motor has been unveiled with unprecedented detail, showing a two-cogwheel machine propelled by a Brownian ratchet device. Additionally, by imaging the flagellin-like protomers that make up the hook in its native bent configuration, their unexpected conformational plasticity challenges the paradigm of a two-state conformational rearrangement mechanism for flagellin-fold proteins. Finally, imaging of the filaments of periplasmic flagella, which endow Spirochete bacteria with their singular motility style, uncovered a strikingly asymmetric protein sheath that coats the flagellin core, challenging the view of filaments as simple homopolymeric structures that work as freely whirling whips. Further research will shed more light on the functional details of this amazing nanomachine, but our current understanding has definitely come a long way.
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Affiliation(s)
- Sonia Mondino
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay; Integrative Microbiology of Zoonotic Agents IMiZA Unit, Joint International Unit, Institut Pasteur/Institut Pasteur de Montevideo, France/Uruguay
| | - Fabiana San Martin
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay; Integrative Microbiology of Zoonotic Agents IMiZA Unit, Joint International Unit, Institut Pasteur/Institut Pasteur de Montevideo, France/Uruguay
| | - Alejandro Buschiazzo
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay; Integrative Microbiology of Zoonotic Agents IMiZA Unit, Joint International Unit, Institut Pasteur/Institut Pasteur de Montevideo, France/Uruguay; Microbiology Department, Institut Pasteur, Paris, France.
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26
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Wang D, Mukhtar A, Humayun M, Wu K, Du Z, Wang S, Zhang Y. A Critical Review on Nanowire-Motors: Design, Mechanism and Applications. CHEM REC 2022; 22:e202200016. [PMID: 35616156 DOI: 10.1002/tcr.202200016] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/24/2022] [Indexed: 01/18/2023]
Abstract
Nanowire-motors (NW-Ms) are promoting the rapid development of emerging biomedicine and environmental governance, and are an important branch of micro-nano motors in the development of nanotechnology. In recent years, huge research breakthroughs have been made in these fields in terms of the fascinating microstructure, conversion efficiency and practical applications of NW-Ms. This review article introduces the latest milestones in NW-Ms research, from production methods, driving mechanisms, control methods to targeted drug delivery, sewage detection, sensors and cell capture. The dynamics and physics of micro-nano devices are reviewed, and finally the current challenges and future research directions in this field are discussed. This review further aims to provide certain guidance for the driving of NW-Ms to meet the urgent needs of emerging applications.
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Affiliation(s)
- Dashuang Wang
- College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China
| | - Aiman Mukhtar
- The State Key Laboratory of Refractories and Metallurgy, International Research Institute for Steel Technology, Collaborative Innovation Center for Advanced Steels, Wuhan University of Science and Technology, Wuhan, 430081, China
| | - Muhammad Humayun
- School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Engineering Research Center for Functional Ceramics of the Ministry of Education, Huazhong University of Science and Technology, Wuhan, 430074, PR China
| | - Kaiming Wu
- The State Key Laboratory of Refractories and Metallurgy, International Research Institute for Steel Technology, Collaborative Innovation Center for Advanced Steels, Wuhan University of Science and Technology, Wuhan, 430081, China
| | - Zhilan Du
- College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China
| | - Shushen Wang
- The State Key Laboratory of Refractories and Metallurgy, International Research Institute for Steel Technology, Collaborative Innovation Center for Advanced Steels, Wuhan University of Science and Technology, Wuhan, 430081, China
| | - Yuxin Zhang
- College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China
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27
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Hesaraki M, Bora U, Pahlavan S, Salehi N, Mousavi SA, Barekat M, Rasouli SJ, Baharvand H, Ozhan G, Totonchi M. A Novel Missense Variant in Actin Binding Domain of MYH7 Is Associated With Left Ventricular Noncompaction. Front Cardiovasc Med 2022; 9:839862. [PMID: 35463789 PMCID: PMC9024299 DOI: 10.3389/fcvm.2022.839862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/22/2022] [Indexed: 11/17/2022] Open
Abstract
Cardiomyopathies are a group of common heart disorders that affect numerous people worldwide. Left ventricular non-compaction (LVNC) is a structural disorder of the ventricular wall, categorized as a type of cardiomyopathy that mostly caused by genetic disorders. Genetic variations are underlying causes of developmental deformation of the heart wall and the resultant contractile insufficiency. Here, we investigated a family with several affected members exhibiting LVNC phenotype. By whole-exome sequencing (WES) of three affected members, we identified a novel heterozygous missense variant (c.1963C>A:p.Leu655Met) in the gene encoding myosin heavy chain 7 (MYH7). This gene is evolutionary conserved among different organisms. We identified MYH7 as a highly enriched myosin, compared to other types of myosin heavy chains, in skeletal and cardiac muscles. Furthermore, MYH7 was among a few classes of MYH in mouse heart that highly expresses from early embryonic to adult stages. In silico predictions showed an altered actin-myosin binding, resulting in weaker binding energy that can cause LVNC. Moreover, CRISPR/Cas9 mediated MYH7 knockout in zebrafish caused impaired cardiovascular development. Altogether, these findings provide the first evidence for involvement of p.Leu655Met missense variant in the incidence of LVNC, most probably through actin-myosin binding defects during ventricular wall morphogenesis.
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Affiliation(s)
- Mahdi Hesaraki
- Department of Developmental Biology, School of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, Tehran, Iran
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Ugur Bora
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Izmir, Turkey
| | - Sara Pahlavan
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Najmeh Salehi
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
- School of Biological Science, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
| | - Seyed Ahmad Mousavi
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Maryam Barekat
- Department of Regenerative Medicine, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Seyed Javad Rasouli
- Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Hossein Baharvand
- Department of Developmental Biology, School of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, Tehran, Iran
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Gunes Ozhan
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Izmir, Turkey
- *Correspondence: Gunes Ozhan
| | - Mehdi Totonchi
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
- School of Biological Science, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
- Mehdi Totonchi
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28
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Debold EP. Mini‐ review: Recent insights into the relative timing of myosin’s powerstroke and release of phosphate. Cytoskeleton (Hoboken) 2022; 78:448-458. [DOI: 10.1002/cm.21695] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/25/2022] [Accepted: 03/08/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Edward P. Debold
- Department of Kinesiology University of Massachusetts Amherst Massachusetts
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29
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The Local Environment of Loop Switch 1 Modulates the Rate of ATP-Induced Dissociation of Human Cardiac Actomyosin. Int J Mol Sci 2022; 23:ijms23031220. [PMID: 35163146 PMCID: PMC8835826 DOI: 10.3390/ijms23031220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 02/04/2023] Open
Abstract
Two isoforms of human cardiac myosin, alpha and beta, share significant sequence similarities but show different kinetics. The alpha isoform is a faster motor; it spends less time being strongly bound to actin during the actomyosin cycle. With alpha isoform, actomyosin dissociates faster upon ATP binding, and the affinity of ADP to actomyosin is weaker. One can suggest that the isoform-specific actomyosin kinetics is regulated at the nucleotide binding site of human cardiac myosin. Myosin is a P-loop ATPase; the nucleotide-binding site consists of P-loop and loops switch 1 and 2. All three loops position MgATP for successful hydrolysis. Loops sequence is conserved in both myosin isoforms, and we hypothesize that the isoform-specific structural element near the active site regulates the rate of nucleotide binding and release. Previously we ran molecular dynamics simulations and found that loop S291-E317 near loop switch 1 is more compact and exhibits larger fluctuations of the position of amino acid residues in beta isoform than in alpha. In alpha isoform, the loop forms a salt bridge with loop switch 1, the bridge is not present in beta isoform. Two isoleucines I303 and I313 of loop S291-E317 are replaced with valines in alpha isoform. We introduced a double mutation I303V:I313V in beta isoform background and studied how the mutation affects the rate of ATP binding and ADP dissociation from actomyosin. We found that ATP-induced actomyosin dissociation occurs faster in the mutant, but the rate of ADP release remains the same as in the wild-type beta isoform. Due to the proximity of loop S291-E317 and loop switch 1, a faster rate of ATP-induced actomyosin dissociation indicates that loop S291-E317 affects structural dynamics of loop switch 1, and that loop switch 1 controls ATP binding to the active site. A similar rate of ADP dissociation from actomyosin in the mutant and wild-type myosin constructs indicates that loop switch 1 does not control ADP release from actomyosin.
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30
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Sun S, Karki C, Gao BZ, Li L. Molecular mechanisms of cardiac actomyosin transforming from rigor state to post-rigor state. J Chem Phys 2022; 156:035101. [PMID: 35065578 PMCID: PMC9305598 DOI: 10.1063/5.0078166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Sudden cardiac death contributed to half of all deaths from cardiovascular diseases. The mechanism of the kinetic cycle of cardiac myosin is crucial for heart protection and drug development. The state change in the myosin kinetic cycle from the rigor state to the post-rigor state is fundamental to explain binding and dissociation. Here, we used β-cardiac myosin in the rigor and post-rigor states to model the actomyosin complexes. Molecular dynamics simulations, electrostatic analysis, and energetic analysis of actomyosin complexes were performed in this work. The results showed that there are fewer interactions and lower electrostatic binding strength in the post-rigor state than in the rigor state. In the post-rigor state, there were higher free binding energy, fewer salt bridges, and fewer hydrogen bonds. The results showed a lower binding affinity in the post-rigor state than in the rigor state. The decrease in the binding affinity provided important conditions for dissociation of the myosin from the actin filament. Although previous studies focused mostly on the binding process, this study provides evidence of dissociation, which is even more important in the myosin kinetic cycle. This research on the mechanism of myosin kinetic cycles provides a novel direction for future genetic disease studies.
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Affiliation(s)
- Shengjie Sun
- Computational Science Program, The University of Texas at El Paso, 500 W University Ave., El Paso, Texas 79968, USA
| | - Chitra Karki
- Computational Science Program, The University of Texas at El Paso, 500 W University Ave., El Paso, Texas 79968, USA
| | - Bruce Z. Gao
- Department of Bioengineering, Clemson University, Clemson, South Carolina 29634, USA
| | - Lin Li
- Author to whom correspondence should be addressed:
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31
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Abstract
In contrast to conventional hard actuators, soft actuators offer many vivid advantages, such as improved flexibility, adaptability, and reconfigurability, which are intrinsic to living systems. These properties make them particularly promising for different applications, including soft electronics, surgery, drug delivery, artificial organs, or prosthesis. The additional degree of freedom for soft actuatoric devices can be provided through the use of intelligent materials, which are able to change their structure, macroscopic properties, and shape under the influence of external signals. The use of such intelligent materials allows a substantial reduction of a device's size, which enables a number of applications that cannot be realized by externally powered systems. This review aims to provide an overview of the properties of intelligent synthetic and living/natural materials used for the fabrication of soft robotic devices. We discuss basic physical/chemical properties of the main kinds of materials (elastomers, gels, shape memory polymers and gels, liquid crystalline elastomers, semicrystalline ferroelectric polymers, gels and hydrogels, other swelling polymers, materials with volume change during melting/crystallization, materials with tunable mechanical properties, and living and naturally derived materials), how they are related to actuation and soft robotic application, and effects of micro/macro structures on shape transformation, fabrication methods, and we highlight selected applications.
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Affiliation(s)
- Indra Apsite
- Faculty of Engineering Science, Department of Biofabrication, University of Bayreuth, Ludwig Thoma Str. 36A, 95447 Bayreuth, Germany
| | - Sahar Salehi
- Department of Biomaterials, Center of Energy Technology und Materials Science, University of Bayreuth, Prof.-Rüdiger-Bormann-Straße 1, 95447 Bayreuth, Germany
| | - Leonid Ionov
- Faculty of Engineering Science, Department of Biofabrication, University of Bayreuth, Ludwig Thoma Str. 36A, 95447 Bayreuth, Germany.,Bavarian Polymer Institute, University of Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany
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32
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Rall JA. Investigation of the molecular motor of muscle: from generating life in a test tube to myosin structure over beers. ADVANCES IN PHYSIOLOGY EDUCATION 2021; 45:730-743. [PMID: 34498938 DOI: 10.1152/advan.00077.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
This article traces 60 years of investigation of the molecular motor of skeletal muscle from the 1940s through the 1990s. It started with the discovery that myosin interaction with actin in the presence of ATP caused shortening of threads of actin and myosin. In 1957, structures protruding from myosin filaments were seen for the first time and called "cross bridges." A combination of techniques led to the proposal in 1969 of the "swinging-tilting cross bridge" model of contraction. In the early 1980s, a major problem arose when it was shown that a probe attached to the cross bridges did not move during contraction. A spectacular breakthrough came when it was discovered that only the cross bridge was required to support movement in an in vitro motility assay. Next it was determined that single myosin molecules caused the movement of actin filaments in 10-nm steps. The atomic structure of the cross bridge was published in 1993, and this discovery supercharged the muscle field. The cross bridge contained a globular head or motor domain that bound actin and ATP. But the most striking feature was the long tail of the cross bridge surrounded by two subunits of the myosin molecule. This structure suggested that the tail might act as a lever arm magnifying head movement. Consistent with this proposal, genetic techniques that lengthened the lever arm resulted in larger myosin steps. Thus the molecular motor of muscle operated not by the tilting of the globular head of myosin but by tilting of the lever arm generating the driving force for contraction.
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Affiliation(s)
- Jack A Rall
- Department of Physiology and Cell Biology, College of Medicine, Ohio State University, Columbus, Ohio
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33
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Pospich S, Sweeney HL, Houdusse A, Raunser S. High-resolution structures of the actomyosin-V complex in three nucleotide states provide insights into the force generation mechanism. eLife 2021; 10:e73724. [PMID: 34812732 PMCID: PMC8735999 DOI: 10.7554/elife.73724] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
The molecular motor myosin undergoes a series of major structural transitions during its force-producing motor cycle. The underlying mechanism and its coupling to ATP hydrolysis and actin binding are only partially understood, mostly due to sparse structural data on actin-bound states of myosin. Here, we report 26 high-resolution cryo-EM structures of the actomyosin-V complex in the strong-ADP, rigor, and a previously unseen post-rigor transition state that binds the ATP analog AppNHp. The structures reveal a high flexibility of myosin in each state and provide valuable insights into the structural transitions of myosin-V upon ADP release and binding of AppNHp, as well as the actomyosin interface. In addition, they show how myosin is able to specifically alter the structure of F-actin.
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Affiliation(s)
- Sabrina Pospich
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
| | - H Lee Sweeney
- Department of Pharmacology and Therapeutics and the Myology Institute, University of FloridaGainesvilleUnited States
| | - Anne Houdusse
- Structural Motility, Institut Curie, Centre National de la Recherche ScientifiqueParisFrance
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
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34
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Fucili A, Cimaglia P, Severi P, Giannini F, Boccadoro A, Micillo M, Rapezzi C, Tavazzi L, Ferrari R. Looking for a Tailored Therapy for Heart Failure: Are We Capable of Treating the Patient Instead of the Disease? J Clin Med 2021; 10:jcm10194325. [PMID: 34640341 PMCID: PMC8509308 DOI: 10.3390/jcm10194325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/23/2021] [Accepted: 09/16/2021] [Indexed: 12/11/2022] Open
Abstract
After almost a decade of stagnation in clinical research for HF treatment, five large randomized trials recently published have supported the use of four new classes of drugs, namely: angiotensin receptor/neprilysin inhibitor, sodium-glucose co-transporters 2 inhibitors, soluble guanylate cyclase modulators, and myosin activators. Each treatment has proved to be beneficial for both long-term outcomes and quality of life. Beside their clinical relevance, all these novel treatments have a different mechanism of action beyond the usual neuro-hormonal blockage. These different pathways, together with the unquestionable clinical evidence, advocate a re-thinking of HF treatment and of the appropriate drug to integrate with the existing standard therapy, according to different characteristics of HFrEF patients. This study aimed to offer a synthetic overview of the mechanisms of action of the new drugs and to propose a more personalized approach, considering patients' characteristics and safety profiles. To this end, we have identified seven profiles for patients with chronic heart failure with reduced ejection fraction and two for pre-discharge patients.
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Affiliation(s)
- Alessandro Fucili
- Cardiovascular Research Centre, Ferrara University, Via Aldo Moro 8, 44124 Ferrara, Italy; (A.F.); (P.S.); (A.B.); (M.M.); (C.R.)
| | - Paolo Cimaglia
- Cardiovascular Department, GVM Care and Research, Maria Cecilia Hospital, Via Corriera 1, 48033 Cotignola, Italy; (P.C.); (F.G.); (L.T.)
| | - Paolo Severi
- Cardiovascular Research Centre, Ferrara University, Via Aldo Moro 8, 44124 Ferrara, Italy; (A.F.); (P.S.); (A.B.); (M.M.); (C.R.)
| | - Francesco Giannini
- Cardiovascular Department, GVM Care and Research, Maria Cecilia Hospital, Via Corriera 1, 48033 Cotignola, Italy; (P.C.); (F.G.); (L.T.)
| | - Alberto Boccadoro
- Cardiovascular Research Centre, Ferrara University, Via Aldo Moro 8, 44124 Ferrara, Italy; (A.F.); (P.S.); (A.B.); (M.M.); (C.R.)
| | - Marco Micillo
- Cardiovascular Research Centre, Ferrara University, Via Aldo Moro 8, 44124 Ferrara, Italy; (A.F.); (P.S.); (A.B.); (M.M.); (C.R.)
| | - Claudio Rapezzi
- Cardiovascular Research Centre, Ferrara University, Via Aldo Moro 8, 44124 Ferrara, Italy; (A.F.); (P.S.); (A.B.); (M.M.); (C.R.)
- Cardiovascular Department, GVM Care and Research, Maria Cecilia Hospital, Via Corriera 1, 48033 Cotignola, Italy; (P.C.); (F.G.); (L.T.)
| | - Luigi Tavazzi
- Cardiovascular Department, GVM Care and Research, Maria Cecilia Hospital, Via Corriera 1, 48033 Cotignola, Italy; (P.C.); (F.G.); (L.T.)
| | - Roberto Ferrari
- Cardiovascular Research Centre, Ferrara University, Via Aldo Moro 8, 44124 Ferrara, Italy; (A.F.); (P.S.); (A.B.); (M.M.); (C.R.)
- Cardiovascular Department, GVM Care and Research, Maria Cecilia Hospital, Via Corriera 1, 48033 Cotignola, Italy; (P.C.); (F.G.); (L.T.)
- Via Ercole I° D’Este 32, 44124 Ferrara, Italy
- Correspondence: ; Tel.: +39-0532-293707
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35
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Chu S, Muretta JM, Thomas DD. Direct detection of the myosin super-relaxed state and interacting-heads motif in solution. J Biol Chem 2021; 297:101157. [PMID: 34481842 PMCID: PMC8479475 DOI: 10.1016/j.jbc.2021.101157] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/31/2021] [Accepted: 08/31/2021] [Indexed: 11/30/2022] Open
Abstract
The interacting-heads motif (IHM) is a structure of myosin that has been proposed to modulate cardiac output by occluding myosin molecules from undergoing the force-generating cycle. It is hypothesized to be the structural basis for the super-relaxed state (SRX), a low-ATPase kinetic state thought to be cardioprotective. The goal of the present study was to test this hypothesis by determining directly and quantitatively the fractions of myosin in the IHM and SRX under the same conditions in solution. To detect the structural IHM, we used time-resolved fluorescence resonance energy transfer to quantitate two distinct populations. One population was observed at a center distance of 2.0 nm, whereas the other was not detectable by fluorescence resonance energy transfer, implying a distance greater than 4 nm. We confirmed the IHM assignment to the 2.0-nm population by applying the same cross-linking protocol used previously to image the IHM by electron microscopy. Under the same conditions, we also measured the fraction of myosin in the SRX using stopped-flow kinetics. Our results show that the populations of SRX and IHM myosin were similar, unless treated with mavacamten, a drug that recently completed phase III clinical trials to treat hypertrophic cardiomyopathy and is proposed to act by stabilizing both the SRX and IHM. However, we found that mavacamten had a much greater effect on the SRX (55% increase) than on the IHM (4% increase). We conclude that the IHM structure is sufficient but not necessary to produce the SRX kinetic state.
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Affiliation(s)
- Sami Chu
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Joseph M Muretta
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA.
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36
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Scott B, Marang C, Woodward M, Debold EP. Myosin's powerstroke occurs prior to the release of phosphate from the active site. Cytoskeleton (Hoboken) 2021; 78:185-198. [PMID: 34331410 DOI: 10.1002/cm.21682] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 02/06/2023]
Abstract
Myosins are a family of motor proteins responsible for various forms of cellular motility, including muscle contraction and vesicular transport. The most fundamental aspect of myosin is its ability to transduce the chemical energy from the hydrolysis of ATP into mechanical work, in the form of force and/or motion. A key unanswered question of the transduction process is the timing of the force-generating powerstroke relative to the release of phosphate (Pi ) from the active site. We examined the ability of single-headed myosin Va to generate a powerstroke in a single molecule laser trap assay while maintaining Pi in its active site, by either elevating Pi in solution or by introducing a mutation in myosin's active site (S217A) to slow Pi -release from the active site. Upon binding to the actin filament, WT myosin generated a powerstoke rapidly (≥500 s-1 ) and without a detectable delay, both in the absence and presence of 30 mM Pi . The elevated levels of Pi did, however, affect event lifetime, eliminating the longest 25% of binding events, confirming that Pi rebound to myosin's active site and accelerated detachment. The S217A construct also generated a powerstroke similar in size and rate upon binding to actin despite the slower Pi release rate. These findings provide direct evidence that myosin Va generates a powerstroke with Pi still in its active site. Therefore, the findings are most consistent with a model in which the powerstroke occurs prior to the release of Pi from the active site.
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Affiliation(s)
- Brent Scott
- Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Christopher Marang
- Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Mike Woodward
- Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Edward P Debold
- Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, USA
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Three-color single-molecule imaging reveals conformational dynamics of dynein undergoing motility. Proc Natl Acad Sci U S A 2021; 118:2101391118. [PMID: 34326255 PMCID: PMC8346880 DOI: 10.1073/pnas.2101391118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Dynein, a dimeric motor protein, moves along microtubules through adenosine 5′-triphosphate- and thermal-driven motions of two large ring domains (AAA rings) and small microtubule-binding domains (MTBDs) separated by a long coiled-coil. Previous single-molecule studies have tracked the positions of the AAA rings during motility, but not the MTBDs. Here, we tracked the relative positions of both MTBDs and one AAA ring by three-color, nanometer-resolution imaging. The observation of both MTBDs provided a direct measurement of how dynein steps on the tubulin subunits, and the simultaneous observation of three fiducial markers revealed extraordinary flexibility and previously unknown conformational states of the motor during motility. The techniques presented here can be used to explore conformational dynamics of many other macromolecular complexes. The motor protein dynein undergoes coordinated conformational changes of its domains during motility along microtubules. Previous single-molecule studies analyzed the motion of the AAA rings of the dynein homodimer, but not the distal microtubule-binding domains (MTBDs) that step along the track. Here, we simultaneously tracked with nanometer precision two MTBDs and one AAA ring of a single dynein as it underwent hundreds of steps using three-color imaging. We show that the AAA ring and the MTBDs do not always step simultaneously and can take differently sized steps. This variability in the movement between the AAA ring and MTBDs results in an unexpectedly large number of conformational states of dynein during motility. Extracting data on conformational transition biases, we could accurately model dynein stepping in silico. Our results reveal that the flexibility between major dynein domains is critical for dynein motility.
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38
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Quantification and demonstration of the collective constriction-by-ratchet mechanism in the dynamin molecular motor. Proc Natl Acad Sci U S A 2021; 118:2101144118. [PMID: 34244431 PMCID: PMC8285958 DOI: 10.1073/pnas.2101144118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Dynamin is a protein that is a central player in endocytosis, a process that mediates the entry of diverse particles into cells, from nutrients to viruses. Dynamin’s primary activity is to use guanosine triphosphate as fuel to constrict and cut membrane tubes. Key quantitative aspects of its function remain yet unclear. In this work, we determine the strength of an individual dynamin motor. Then, by building a detailed computational model resolving individual motors, we demonstrate that dynamin produces sufficient force to tightly constrict a membrane tube when most of its motors are simultaneously cooperating. Hence, we quantitatively validate the prevailing constriction-by-ratchet model for nature’s strongest torque-generating motor: the dynamin “nanomuscle.” Dynamin oligomerizes into helical filaments on tubular membrane templates and, through constriction, cleaves them in a GTPase-driven way. Structural observations of GTP-dependent cross-bridges between neighboring filament turns have led to the suggestion that dynamin operates as a molecular ratchet motor. However, the proof of such mechanism remains absent. Particularly, it is not known whether a powerful enough stroke is produced and how the motor modules would cooperate in the constriction process. Here, we characterized the dynamin motor modules by single-molecule Förster resonance energy transfer (smFRET) and found strong nucleotide-dependent conformational preferences. Integrating smFRET with molecular dynamics simulations allowed us to estimate the forces generated in a power stroke. Subsequently, the quantitative force data and the measured kinetics of the GTPase cycle were incorporated into a model including both a dynamin filament, with explicit motor cross-bridges, and a realistic deformable membrane template. In our simulations, collective constriction of the membrane by dynamin motor modules, based on the ratchet mechanism, is directly reproduced and analyzed. Functional parallels between the dynamin system and actomyosin in the muscle are seen. Through concerted action of the motors, tight membrane constriction to the hemifission radius can be reached. Our experimental and computational study provides an example of how collective motor action in megadalton molecular assemblies can be approached and explicitly resolved.
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Stătescu C, Enachi Ș, Ureche C, Țăpoi L, Anghel L, Șalaru D, Pleșoianu C, Bostan M, Marcu D, Ovanez Balasanian M, Sascău RA. Pushing the Limits of Medical Management in HCM: A Review of Current Pharmacological Therapy Options. Int J Mol Sci 2021; 22:ijms22137218. [PMID: 34281272 PMCID: PMC8268685 DOI: 10.3390/ijms22137218] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common monogenic cardiac disease with a highly variable phenotypic expression, ranging from asymptomatic to drug refractory heart failure (HF) presentation. Pharmacological therapy is the first line of treatment, but options are currently limited to nonspecific medication like betablockers or calcium channel inhibitors, with frequent suboptimal results. While being the gold standard practice for the management of drug refractory HCM patients, septal reduction therapy (SRT) remains an invasive procedure with associated surgical risks and it requires the expertise of the operating centre, thus limiting its accessibility. It is therefore with high interest that researchers look for pharmacological alternatives that could provide higher rates of success. With new data gathering these past years as well as the development of a new drug class showing promising results, this review provides an up-to-date focused synthesis of existing medical treatment options and future directions for HCM pharmacological treatment.
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Affiliation(s)
- Cristian Stătescu
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Ștefana Enachi
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Correspondence: ; Tel.: +40-749-630-641
| | - Carina Ureche
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Laura Țăpoi
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
| | - Larisa Anghel
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Delia Șalaru
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Carmen Pleșoianu
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Mădălina Bostan
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Dragoș Marcu
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Mircea Ovanez Balasanian
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Radu Andy Sascău
- Cardiology Department, Cardiovascular Diseases Institute “Prof. Dr. George I.M. Georgescu”, Carol I Boulevard No. 50, 700503 Iași, Romania; (C.S.); (C.U.); (L.Ț.); (L.A.); (D.Ș.); (C.P.); (M.B.); (D.M.); (M.O.B.); (R.A.S.)
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
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Chakraborti A, Baldo AP, Tardiff JC, Schwartz SD. Investigation of the Recovery Stroke and ATP Hydrolysis and Changes Caused Due to the Cardiomyopathic Point Mutations in Human Cardiac β Myosin. J Phys Chem B 2021; 125:6513-6521. [PMID: 34105970 DOI: 10.1021/acs.jpcb.1c03144] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human cardiac β myosin undergoes the cross-bridge cycle as part of the force-generating mechanism of cardiac muscle. The recovery stroke is considered one of the key steps of the kinetic cycle as it is the conformational rearrangement required to position the active site residues for hydrolysis of ATP and interaction with actin. We explored the free-energy surface of the transition and investigated the effect of the genetic cardiomyopathy causing mutations R453C, I457T, and I467T on this step using metadynamics. This work extends previous studies on Dictyostelium myosin II with engineered mutations. Here, like previously, we generated an unbiased thermodynamic ensemble of reactive trajectories for the chemical step using transition path sampling. Our methodologies were able to predict the changes to the dynamics of the recovery stroke as well as predict the pathway of breakdown of ATP to ADP and HPO42- with the stabilization of the metaphosphate intermediate. We also observed clear differences between the Dictyostelium myosin II and human cardiac β myosin for ATP hydrolysis as well as predict the effect of the mutation I467T on the chemical step.
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Affiliation(s)
- Ananya Chakraborti
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Anthony P Baldo
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Jil C Tardiff
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85724, United States
| | - Steven D Schwartz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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A reverse stroke characterizes the force generation of cardiac myofilaments, leading to an understanding of heart function. Proc Natl Acad Sci U S A 2021; 118:2011659118. [PMID: 34088833 DOI: 10.1073/pnas.2011659118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Changes in the molecular properties of cardiac myosin strongly affect the interactions of myosin with actin that result in cardiac contraction and relaxation. However, it remains unclear how myosin molecules work together in cardiac myofilaments and which properties of the individual myosin molecules impact force production to drive cardiac contractility. Here, we measured the force production of cardiac myofilaments using optical tweezers. The measurements revealed that stepwise force generation was associated with a higher frequency of backward steps at lower loads and higher stall forces than those of fast skeletal myofilaments. To understand these unique collective behaviors of cardiac myosin, the dynamic responses of single cardiac and fast skeletal myosin molecules, interacting with actin filaments, were evaluated under load. The cardiac myosin molecules switched among three distinct conformational positions, ranging from pre- to post-power stroke positions, in 1 mM ADP and 0 to 10 mM phosphate solution. In contrast to cardiac myosin, fast skeletal myosin stayed primarily in the post-power stroke position, suggesting that cardiac myosin executes the reverse stroke more frequently than fast skeletal myosin. To elucidate how the reverse stroke affects the force production of myofilaments and possibly heart function, a simulation model was developed that combines the results from the single-molecule and myofilament experiments. The results of this model suggest that the reversal of the cardiac myosin power stroke may be key to characterizing the force output of cardiac myosin ensembles and possibly to facilitating heart contractions.
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42
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Cardiomyopathy mutations impact the actin-activated power stroke of human cardiac myosin. Biophys J 2021; 120:2222-2236. [PMID: 33864791 DOI: 10.1016/j.bpj.2021.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/02/2021] [Accepted: 04/01/2021] [Indexed: 11/24/2022] Open
Abstract
Cardiac muscle contraction is driven by the molecular motor myosin, which uses the energy from ATP hydrolysis to generate a power stroke when interacting with actin filaments, although it is unclear how this mechanism is impaired by mutations in myosin that can lead to heart failure. We have applied a fluorescence resonance energy transfer (FRET) strategy to investigate structural changes in the lever arm domain of human β-cardiac myosin subfragment 1 (M2β-S1). We exchanged the human ventricular regulatory light chain labeled at a single cysteine (V105C) with Alexa 488 onto M2β-S1, which served as a donor for Cy3ATP bound to the active site. We monitored the FRET signal during the actin-activated product release steps using transient kinetic measurements. We propose that the fast phase measured with our FRET probes represents the macroscopic rate constant associated with actin-activated rotation of the lever arm during the power stroke in M2β-S1. Our results demonstrated M2β-S1 has a slower actin-activated power stroke compared with fast skeletal muscle myosin and myosin V. Measurements at different temperatures comparing the rate constants of the actin-activated power stroke and phosphate release are consistent with a model in which the power stroke occurs before phosphate release and the two steps are tightly coupled. We suggest that the actin-activated power stroke is highly reversible but followed by a highly irreversible phosphate release step in the absence of load and free phosphate. We demonstrated that hypertrophic cardiomyopathy (R723G)- and dilated cardiomyopathy (F764L)-associated mutations both reduced actin activation of the power stroke in M2β-S1. We also demonstrate that both mutations alter in vitro actin gliding in the presence and absence of load. Thus, examining the structural kinetics of the power stroke in M2β-S1 has revealed critical mutation-associated defects in the myosin ATPase pathway, suggesting these measurements will be extremely important for establishing structure-based mechanisms of contractile dysfunction.
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43
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Gunther LK, Rohde JA, Tang W, Cirilo JA, Marang CP, Scott BD, Thomas DD, Debold EP, Yengo CM. FRET and optical trapping reveal mechanisms of actin activation of the power stroke and phosphate release in myosin V. J Biol Chem 2021; 295:17383-17397. [PMID: 33453985 DOI: 10.1074/jbc.ra120.015632] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 10/06/2020] [Indexed: 11/06/2022] Open
Abstract
Myosins generate force and motion by precisely coordinating their mechanical and chemical cycles, but the nature and timing of this coordination remains controversial. We utilized a FRET approach to examine the kinetics of structural changes in the force-generating lever arm in myosin V. We directly compared the FRET results with single-molecule mechanical events examined by optical trapping. We introduced a mutation (S217A) in the conserved switch I region of the active site to examine how myosin couples structural changes in the actin- and nucleotide-binding regions with force generation. Specifically, S217A enhanced the maximum rate of lever arm priming (recovery stroke) while slowing ATP hydrolysis, demonstrating that it uncouples these two steps. We determined that the mutation dramatically slows both actin-induced rotation of the lever arm (power stroke) and phosphate release (≥10-fold), whereas our simulations suggest that the maximum rate of both steps is unchanged by the mutation. Time-resolved FRET revealed that the structure of the pre- and post-power stroke conformations and mole fractions of these conformations were not altered by the mutation. Optical trapping results demonstrated that S217A does not dramatically alter unitary displacements or slow the working stroke rate constant, consistent with the mutation disrupting an actin-induced conformational change prior to the power stroke. We propose that communication between the actin- and nucleotide-binding regions of myosin assures a proper actin-binding interface and active site have formed before producing a power stroke. Variability in this coupling is likely crucial for mediating motor-based functions such as muscle contraction and intracellular transport.
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Affiliation(s)
- Laura K Gunther
- Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA
| | - John A Rohde
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Wanjian Tang
- Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA
| | - Joseph A Cirilo
- Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA
| | - Christopher P Marang
- Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Brent D Scott
- Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Edward P Debold
- Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA.
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Abouward R, Schiavo G. Walking the line: mechanisms underlying directional mRNA transport and localisation in neurons and beyond. Cell Mol Life Sci 2021; 78:2665-2681. [PMID: 33341920 PMCID: PMC8004493 DOI: 10.1007/s00018-020-03724-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/02/2020] [Accepted: 11/25/2020] [Indexed: 12/21/2022]
Abstract
Messenger RNA (mRNA) localisation enables a high degree of spatiotemporal control on protein synthesis, which contributes to establishing the asymmetric protein distribution required to set up and maintain cellular polarity. As such, a tight control of mRNA localisation is essential for many biological processes during development and in adulthood, such as body axes determination in Drosophila melanogaster and synaptic plasticity in neurons. The mechanisms controlling how mRNAs are localised, including diffusion and entrapment, local degradation and directed active transport, are largely conserved across evolution and have been under investigation for decades in different biological models. In this review, we will discuss the standing of the field regarding directional mRNA transport in light of the recent discovery that RNA can hitchhike on cytoplasmic organelles, such as endolysosomes, and the impact of these transport modalities on our understanding of neuronal function during development, adulthood and in neurodegeneration.
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Affiliation(s)
- Reem Abouward
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
- UK Dementia Research Institute, University College London, London, WC1E 6BT, UK
- The Francis Crick Institute, 1 Midland Rd, London, NW1 1AT, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK.
- UK Dementia Research Institute, University College London, London, WC1E 6BT, UK.
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45
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Mugnai ML, Thirumalai D. Step-Wise Hydration of Magnesium by Four Water Molecules Precedes Phosphate Release in a Myosin Motor. J Phys Chem B 2021; 125:1107-1117. [PMID: 33481593 DOI: 10.1021/acs.jpcb.0c10004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular motors, such as myosin, kinesin, and dynein, convert the energy released by the hydrolysis of ATP into mechanical work, thus allowing them to undergo directional motion on cytoskeletal tracks. A pivotal step in the chemomechanical transduction in myosin motors occurs after they bind to the actin filament, which triggers the release of phosphate (Pi, product of ATP hydrolysis) and the rotation of the lever arm. Here, we investigate the mechanism of phosphate release in myosin VI using extensive molecular dynamics simulations involving multiple trajectories of several μs. Because the escape of phosphate is expected to occur on time-scales on the order of milliseconds or more in myosin VI, we observed Pi release only if the trajectories were initiated with a rotated phosphate inside the nucleotide binding pocket. We discovered that although Pi populates the traditional "back door" route, phosphate exits through various other gateways, thus establishing the heterogeneity in the escape routes. Remarkably, we observed that the release of phosphate is preceded by a stepwise hydration of the ADP-bound magnesium ion. The release of the anion occurred only after four water molecules hydrated the cation (Mg2+). By performing comparative structural analyses, we show that hydration of magnesium is the key step in the phosphate release in a number of ATPases and GTPases. Nature may have evolved hydration of Mg2+ as a general molecular switch for Pi release, which is a universal step in the catalytic cycle of many machines that share little sequence or structural similarity.
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Affiliation(s)
- Mauro Lorenzo Mugnai
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - D Thirumalai
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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46
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Modulation of post-powerstroke dynamics in myosin II by 2'-deoxy-ADP. Arch Biochem Biophys 2020; 699:108733. [PMID: 33388313 DOI: 10.1016/j.abb.2020.108733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/25/2020] [Accepted: 12/18/2020] [Indexed: 01/10/2023]
Abstract
Muscle myosins are molecular motors that hydrolyze ATP and generate force through coordinated interactions with actin filaments, known as cross-bridge cycling. During the cross-bridge cycle, functional sites in myosin 'sense' changes in interactions with actin filaments and the nucleotide binding region, resulting in allosteric transmission of information throughout the structure. We investigated whether the dynamics of the post-powerstroke state of the cross-bridge cycle are modulated in a nucleotide-dependent fashion. We compared molecular dynamics simulations of the myosin II motor domain (M) from Dictyostelium discoideum in the presence of ADP (M.ADP) versus 2'-deoxy-ADP bound myosin (M.dADP). We found that dADP was more flexible than ADP and the two nucleotides interacted with myosin in different ways. Replacement of ADP with dADP in the post-powerstroke state also altered the conformation of the actin binding region in myosin heads. Our results provide atomic level insights into allosteric communication networks in myosin that provide insight into the nucleotide-dependent dynamics of the cross-bridge cycle.
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47
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Franz P, Ewert W, Preller M, Tsiavaliaris G. Unraveling a Force-Generating Allosteric Pathway of Actomyosin Communication Associated with ADP and P i Release. Int J Mol Sci 2020; 22:ijms22010104. [PMID: 33374308 PMCID: PMC7795666 DOI: 10.3390/ijms22010104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/20/2020] [Accepted: 12/21/2020] [Indexed: 11/16/2022] Open
Abstract
The actomyosin system generates mechanical work with the execution of the power stroke, an ATP-driven, two-step rotational swing of the myosin-neck that occurs post ATP hydrolysis during the transition from weakly to strongly actin-bound myosin states concomitant with Pi release and prior to ADP dissociation. The activating role of actin on product release and force generation is well documented; however, the communication paths associated with weak-to-strong transitions are poorly characterized. With the aid of mutant analyses based on kinetic investigations and simulations, we identified the W-helix as an important hub coupling the structural changes of switch elements during ATP hydrolysis to temporally controlled interactions with actin that are passed to the central transducer and converter. Disturbing the W-helix/transducer pathway increased actin-activated ATP turnover and reduced motor performance as a consequence of prolonged duration of the strongly actin-attached states. Actin-triggered Pi release was accelerated, while ADP release considerably decelerated, both limiting maximum ATPase, thus transforming myosin-2 into a high-duty-ratio motor. This kinetic signature of the mutant allowed us to define the fractional occupancies of intermediate states during the ATPase cycle providing evidence that myosin populates a cleft-closure state of strong actin interaction during the weak-to-strong transition with bound hydrolysis products before accomplishing the power stroke.
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Affiliation(s)
- Peter Franz
- Cellular Biophysics, Institute for Biophysical Chemistry, Hannover Medical School, 30625 Hannover, Germany;
| | - Wiebke Ewert
- Structural Bioinformatics and Chemical Biology, Institute for Biophysical Chemistry, Hannover Medical School, 30625 Hannover, Germany; (W.E.); (M.P.)
| | - Matthias Preller
- Structural Bioinformatics and Chemical Biology, Institute for Biophysical Chemistry, Hannover Medical School, 30625 Hannover, Germany; (W.E.); (M.P.)
- Department of Natural Sciences, University of Applied Sciences Bonn-Rhein-Sieg, 53757 Sankt Augustin, Germany
| | - Georgios Tsiavaliaris
- Cellular Biophysics, Institute for Biophysical Chemistry, Hannover Medical School, 30625 Hannover, Germany;
- Correspondence:
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48
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Abstract
Treatment of myocardial diseases with renin-angiotensin system inhibitors and β-blockers has greatly contributed to improving prognosis. However, these treatments are non-specific, and with the exception of some treatments, radical treatments according to the cause of each disease have not been developed until recent years. But in the past decade, more specific and more upstream treatments based on the molecular mechanism of disease onset have been developed and are emerging. Some of the effects have been shown in clinical practice and already approved. This article outlines the mechanism of action and clinical data of novel therapeutic agents specific for myocardial diseases such as dilated cardiomyopathy, hypertrophic cardiomyopathy, Fabry disease, cardiac amyloidosis, and myocarditis. In the future, we hope that the molecular mechanisms will be further elucidated and new and upstream treatment methods will be developed.
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Baldo AP, Tardiff JC, Schwartz SD. Mechanochemical Function of Myosin II: Investigation into the Recovery Stroke and ATP Hydrolysis. J Phys Chem B 2020; 124:10014-10023. [PMID: 33136401 DOI: 10.1021/acs.jpcb.0c05762] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Myosin regulates muscle function through a complex cycle of conformational rearrangements coupled with the hydrolysis of adenosine triphosphate (ATP). The recovery stroke reorganizes the myosin active site to hydrolyze ATP and cross bridge with the thin filament to produce muscle contraction. Engineered mutations K84M and R704E in Dictyostelium myosin have been designed to specifically inhibit the recovery stroke and have been shown to indirectly affect the ATPase activity of myosin. We investigated these mutagenic perturbations to the recovery stroke and generated thermodynamically correct and unbiased trajectories for native ATP hydrolysis with computationally enhanced sampling methods. Our methodology was able to resolve experimentally observed changes to kinetic and equilibrium dynamics for the recovery stroke with the correct prediction in the severity of these changes. For ATP hydrolysis, the sequential nature along with the stabilization of a metaphosphate intermediate was observed in agreement with previous studies. However, we observed glutamate 459 being utilized as a proton abstractor to prime the attacking water instead of a lytic water, a phenomenon not well categorized in myosin but has in other ATPases. Both rare event methodologies can be extended to human myosin to investigate isoformic differences from Dictyostelium and scan cardiomyopathic mutations to see differential perturbations to kinetics of other conformational changes in myosin such as the power stroke.
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Affiliation(s)
- Anthony P Baldo
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Jil C Tardiff
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85724, United States
| | - Steven D Schwartz
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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Chen H, Zhang YHPJ. Enzymatic regeneration and conservation of ATP: challenges and opportunities. Crit Rev Biotechnol 2020; 41:16-33. [PMID: 33012193 DOI: 10.1080/07388551.2020.1826403] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Adenosine triphosphate (ATP), the universal energy currency of life, has a central role in numerous biochemical reactions with potential for the synthesis of numerous high-value products. ATP can be regenerated by three types of mechanisms: substrate level phosphorylation, oxidative phosphorylation, and photophosphorylation. Current ATP regeneration methods are mainly based on substrate level phosphorylation catalyzed by one enzyme, several cascade enzymes, or in vitro synthetic enzymatic pathways. Among them, polyphosphate kinases and acetate kinase, along with their respective phosphate donors, are the most popular approaches for in vitro ATP regeneration. For in vitro artificial pathways, either ATP-free or ATP-balancing strategies can be implemented via smart pathway design by choosing ATP-independent enzymes. Also, we discuss some remaining challenges and suggest perspectives, especially for industrial biomanufacturing. Development of ATP regeneration systems featuring low cost, high volumetric productivity, long lifetime, flexible compatibility, and great robustness could be one of the bottom-up strategies for cascade biocatalysis and in vitro synthetic biology.
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Affiliation(s)
- Hongge Chen
- College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Yi-Heng P Job Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin Airport Economic Area, Tianjin, China
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