1
|
Kengyel A, Palarz PM, Krohn J, Marquardt A, Greve JN, Heiringhoff R, Jörns A, Manstein DJ. Motor properties of Myosin 5c are modulated by tropomyosin isoforms and inhibited by pentabromopseudilin. Front Physiol 2024; 15:1394040. [PMID: 38606007 PMCID: PMC11008601 DOI: 10.3389/fphys.2024.1394040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 03/20/2024] [Indexed: 04/13/2024] Open
Abstract
Myosin 5c (Myo5c) is a motor protein that is produced in epithelial and glandular tissues, where it plays an important role in secretory processes. Myo5c is composed of two heavy chains, each containing a generic motor domain, an elongated neck domain consisting of a single α-helix with six IQ motifs, each of which binds to a calmodulin (CaM) or a myosin light chain from the EF-hand protein family, a coiled-coil dimer-forming region and a carboxyl-terminal globular tail domain. Although Myo5c is a low duty cycle motor, when two or more Myo5c-heavy meromyosin (HMM) molecules are linked together, they move processively along actin filaments. We describe the purification and functional characterization of human Myo5c-HMM co-produced either with CaM alone or with CaM and the essential and regulatory light chains Myl6 and Myl12b. We describe the extent to which cofilaments of actin and Tpm1.6, Tpm1.8 or Tpm3.1 alter the maximum actin-activated ATPase and motile activity of the recombinant Myo5c constructs. The small allosteric effector pentabromopseudilin (PBP), which is predicted to bind in a groove close to the actin and nucleotide binding site with a calculated ΔG of -18.44 kcal/mol, inhibits the motor function of Myo5c with a half-maximal concentration of 280 nM. Using immunohistochemical staining, we determined the distribution and exact localization of Myo5c in endothelial and endocrine cells from rat and human tissue. Particular high levels of Myo5c were observed in insulin-producing β-cells located within the pancreatic islets of Langerhans.
Collapse
Affiliation(s)
- András Kengyel
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
- Department of Biophysics, University of Pécs Medical School, Pécs, Hungary
| | - Philip M. Palarz
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Jacqueline Krohn
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Anja Marquardt
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Johannes N. Greve
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Robin Heiringhoff
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Anne Jörns
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Dietmar J. Manstein
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Carrington G, Fatima U, Caramujo I, Lewis T, Casas-Mao D, Peckham M. A multiscale approach reveals the molecular architecture of the autoinhibited kinesin KIF5A. J Biol Chem 2024; 300:105713. [PMID: 38309508 PMCID: PMC10907169 DOI: 10.1016/j.jbc.2024.105713] [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: 11/06/2023] [Revised: 01/23/2024] [Accepted: 01/26/2024] [Indexed: 02/05/2024] Open
Abstract
Kinesin-1 is a microtubule motor that transports cellular cargo along microtubules. KIF5A is one of three kinesin-1 isoforms in humans, all of which are autoinhibited by an interaction between the motor and an IAK motif in the proximal region of the C-terminal tail. The C-terminal tail of KIF5A is ∼80 residues longer than the other two kinesin-1 isoforms (KIF5B and KIF5C) and it is unclear if it contributes to autoinhibition. Mutations in KIF5A cause neuronal diseases and could affect autoinhibition, as reported for a mutation that skips exon 27, altering its C-terminal sequence. Here, we combined negative-stain electron microscopy, crosslinking mass spectrometry (XL-MS) and AlphaFold2 structure prediction to determine the molecular architecture of the full-length autoinhibited KIF5A homodimer, in the absence of light chains. We show that KIF5A forms a compact, bent conformation, through a bend between coiled-coils 2 and 3, around P687. XL-MS of WT KIF5A revealed extensive interactions between residues in the motor, between coiled-coil 1 and the motor, between coiled-coils 1 and 2, with coiled-coils 3 and 4, and the proximal region of the C-terminal tail and the motor in the autoinhibited state, but not between the distal C-terminal region and the rest of the molecule. While negative-stain electron microscopy of exon-27 KIF5A splice mutant showed the presence of autoinhibited molecules, XL-MS analysis suggested that its autoinhibited state is more labile. Our model offers a conceptual framework for understanding how mutations within the motor and stalk domain may affect motor activity.
Collapse
Affiliation(s)
- Glenn Carrington
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Uzrama Fatima
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Ines Caramujo
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Tarek Lewis
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - David Casas-Mao
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Michelle Peckham
- Faculty of Biological Sciences, Astbury Centre for Structural Biology and the School of Molecular and Cellular Biology, University of Leeds, Leeds, UK.
| |
Collapse
|
4
|
Bao Y, Jia F, Li M, Xu R, Xie Y, Zhang F, Guo J. Characterizing the Molecular Mechanism of the Lethal C423D Mutation in FgMyoI: A Molecular Perspective. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:1539-1549. [PMID: 38226494 DOI: 10.1021/acs.jafc.3c08648] [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: 01/17/2024]
Abstract
The lethal mutation C423D in Fusarium graminearum myosin I (FgMyoI) occurs close to the binding pocket of the allosteric inhibitor phenamacril and causes severe inhibition on mycelial growth of F. graminearum strain PH-1. Here, based on extensive Gaussian accelerated molecular dynamics simulations and wet experiments, we elucidate the underlying molecular mechanism of the abnormal functioning of the FgMyoIC423D mutant at the atomistic level. Our results suggest that the damaging mutation C423D exhibits a synergistic allosteric inhibition mechanism similar to but more robust than that of phenamacril, including effects on the active site and actin binding. Unlike phenamacril-induced closure of Switch2, the mutation results in unfolding of the N-terminal relay helix with a partially opened Switch2 and blocks the structural rearrangement of the relay/SH1 helices, impairing the proper initiation of the recovery stroke. Due to the significant influence of C423D mutation on the function of FgMyoI, designing covalent inhibitors targeting this site holds tremendous potential.
Collapse
Affiliation(s)
- Yiqiong Bao
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Fangying Jia
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Mengrong Li
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Ran Xu
- Centre for Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao 999078, China
| | - Yanjie Xie
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Feng Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Jingjing Guo
- Centre for Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao 999078, China
| |
Collapse
|
5
|
Liu X, Gennerich A. Insect Cell-Based Expression of Cytoskeletal Motor Proteins for Single-Molecule Studies. Methods Mol Biol 2024; 2694:69-90. [PMID: 37824000 PMCID: PMC10880877 DOI: 10.1007/978-1-0716-3377-9_4] [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: 10/13/2023]
Abstract
Cytoskeletal motor proteins are essential molecular machines that hydrolyze ATP to generate force and motion along cytoskeletal filaments. Members of the dynein and kinesin superfamilies play critical roles in transporting biological payloads (such as proteins, organelles, and vesicles) along microtubule pathways, cause the beating of flagella and cilia, and act within the mitotic and meiotic spindles to segregate replicated chromosomes to progeny cells. Understanding the underlying mechanisms and behaviors of motor proteins is critical to provide better strategies for the treatment of motor protein-related diseases. Here, we provide detailed protocols for the recombinant expression of the Kinesin-1 motor KIF5C using a baculovirus/insect cell system and provide updated protocols for performing single-molecule studies using total internal reflection fluorescence microscopy and optical tweezers to study the motility and force generation of the purified motor.
Collapse
Affiliation(s)
- Xinglei Liu
- Department of Biochemistry and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Arne Gennerich
- Department of Biochemistry and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA.
| |
Collapse
|
6
|
Holló A, Billington N, Takagi Y, Kengyel A, Sellers JR, Liu R. Molecular regulatory mechanism of human myosin-7a. J Biol Chem 2023; 299:105243. [PMID: 37690683 PMCID: PMC10579538 DOI: 10.1016/j.jbc.2023.105243] [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: 06/23/2023] [Revised: 09/01/2023] [Accepted: 09/04/2023] [Indexed: 09/12/2023] Open
Abstract
Myosin-7a is an actin-based motor protein essential for vision and hearing. Mutations of myosin-7a cause type 1 Usher syndrome, the most common and severe form of deafblindness in humans. The molecular mechanisms that govern its mechanochemistry remain poorly understood, primarily because of the difficulty of purifying stable intact protein. Here, we recombinantly produce the complete human myosin-7a holoenzyme in insect cells and characterize its biochemical and motile properties. Unlike the Drosophila ortholog that primarily associates with calmodulin (CaM), we found that human myosin-7a utilizes a unique combination of light chains including regulatory light chain, CaM, and CaM-like protein 4. Our results further reveal that CaM-like protein 4 does not function as a Ca2+ sensor but plays a crucial role in maintaining the lever arm's structural-functional integrity. Using our recombinant protein system, we purified two myosin-7a splicing isoforms that have been shown to be differentially expressed along the cochlear tonotopic axis. We show that they possess distinct mechanoenzymatic properties despite differing by only 11 amino acids at their N termini. Using single-molecule in vitro motility assays, we demonstrate that human myosin-7a exists as an autoinhibited monomer and can move processively along actin when artificially dimerized or bound to cargo adaptor proteins. These results suggest that myosin-7a can serve multiple roles in sensory systems such as acting as a transporter or an anchor/force sensor. Furthermore, our research highlights that human myosin-7a has evolved unique regulatory elements that enable precise tuning of its mechanical properties suitable for mammalian auditory functions.
Collapse
Affiliation(s)
- Alexandra Holló
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA; Department of Biophysics, University of Pécs Medical School, Pécs, Hungary
| | - Neil Billington
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA; Department of Biochemistry & Molecular Medicine, School of Medicine, West Virginia University, Morgantown, West Virginia, USA; Microscope Imaging Facility, West Virginia University, Morgantown, West Virginia, USA
| | - Yasuharu Takagi
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - András Kengyel
- Department of Biophysics, University of Pécs Medical School, Pécs, Hungary; Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - James R Sellers
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
| | - Rong Liu
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA; Department of Biochemistry & Molecular Medicine, School of Medicine, West Virginia University, Morgantown, West Virginia, USA.
| |
Collapse
|
7
|
Vitriol EA, Quintanilla MA, Tidei JJ, Troughton LD, Cody A, Cisterna BA, Jane ML, Oakes PW, Beach JR. Nonmuscle myosin 2 filaments are processive in cells. Biophys J 2023; 122:3678-3689. [PMID: 37218133 PMCID: PMC10541485 DOI: 10.1016/j.bpj.2023.05.014] [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: 02/24/2023] [Revised: 04/26/2023] [Accepted: 05/18/2023] [Indexed: 05/24/2023] Open
Abstract
Directed transport of cellular components is often dependent on the processive movements of cytoskeletal motors. Myosin 2 motors predominantly engage actin filaments of opposing orientation to drive contractile events and are therefore not traditionally viewed as processive. However, recent in vitro experiments with purified nonmuscle myosin 2 (NM2) demonstrated myosin 2 filaments could move processively. Here, we establish processivity as a cellular property of NM2. Processive runs in central nervous system-derived CAD cells are most apparent on bundled actin in protrusions that terminate at the leading edge. We find that processive velocities in vivo are consistent with in vitro measurements. NM2 makes these processive runs in its filamentous form against lamellipodia retrograde flow, though anterograde movement can still occur in the absence of actin dynamics. Comparing the processivity of NM2 isoforms, we find that NM2A moves slightly faster than NM2B. Finally, we demonstrate that this is not a cell-specific property, as we observe processive-like movements of NM2 in the lamella and subnuclear stress fibers of fibroblasts. Collectively, these observations further broaden NM2 functionality and the biological processes in which the already ubiquitous motor can contribute.
Collapse
Affiliation(s)
- Eric A Vitriol
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, Georgia.
| | - Melissa A Quintanilla
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois
| | - Joseph J Tidei
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois
| | - Lee D Troughton
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois
| | - Abigail Cody
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois
| | - Bruno A Cisterna
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, Georgia
| | - Makenzie L Jane
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, Georgia
| | - Patrick W Oakes
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois.
| | - Jordan R Beach
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois.
| |
Collapse
|
8
|
Park J, Bird JE. The actin cytoskeleton in hair bundle development and hearing loss. Hear Res 2023; 436:108817. [PMID: 37300948 PMCID: PMC10408727 DOI: 10.1016/j.heares.2023.108817] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/18/2023] [Accepted: 05/25/2023] [Indexed: 06/12/2023]
Abstract
Inner ear hair cells assemble mechanosensitive hair bundles on their apical surface that transduce sounds and accelerations. Each hair bundle is comprised of ∼ 100 individual stereocilia that are arranged into rows of increasing height and width; their specific and precise architecture being necessary for mechanoelectrical transduction (MET). The actin cytoskeleton is fundamental to establishing this architecture, not only by forming the structural scaffold shaping each stereocilium, but also by composing rootlets and the cuticular plate that together provide a stable foundation supporting each stereocilium. In concert with the actin cytoskeleton, a large assortment of actin-binding proteins (ABPs) function to cross-link actin filaments into specific topologies, as well as control actin filament growth, severing, and capping. These processes are individually critical for sensory transduction and are all disrupted in hereditary forms of human hearing loss. In this review, we provide an overview of actin-based structures in the hair bundle and the molecules contributing to their assembly and functional properties. We also highlight recent advances in mechanisms driving stereocilia elongation and how these processes are tuned by MET.
Collapse
Affiliation(s)
- Jinho Park
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, United States; Myology Institute, University of Florida, Gainesville, FL 32610, United States
| | - Jonathan E Bird
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, United States; Myology Institute, University of Florida, Gainesville, FL 32610, United States.
| |
Collapse
|
9
|
Fineberg A, Takagi Y, Thirumurugan K, Andrecka J, Billington N, Young G, Cole D, Burgess SA, Curd AP, Hammer JA, Sellers JR, Kukura P, Knight PJ. Myosin-5 varies its steps along the irregular F-actin track. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.16.549178. [PMID: 37503193 PMCID: PMC10370000 DOI: 10.1101/2023.07.16.549178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Molecular motors employ chemical energy to generate unidirectional mechanical output against a track. By contrast to the majority of macroscopic machines, they need to navigate a chaotic cellular environment, potential disorder in the track and Brownian motion. Nevertheless, decades of nanometer-precise optical studies suggest that myosin-5a, one of the prototypical molecular motors, takes uniform steps spanning 13 subunits (36 nm) along its F-actin track. Here, we use high-resolution interferometric scattering (iSCAT) microscopy to reveal that myosin takes strides spanning 22 to 34 actin subunits, despite walking straight along the helical actin filament. We show that cumulative angular disorder in F-actin accounts for the observed proportion of each stride length, akin to crossing a river on variably-spaced stepping stones. Electron microscopy revealed the structure of the stepping molecule. Our results indicate that both motor and track are soft materials that can adapt to function in complex cellular conditions.
Collapse
Affiliation(s)
- Adam Fineberg
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- Laboratory of Single Molecule Biophysics, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, U.S.A
| | - Yasuharu Takagi
- Laboratory of Molecular Physiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, U.S.A
| | - Kavitha Thirumurugan
- Astbury Centre for Structural Molecular Biology, and Institute of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, U.K
- Present address: Structural Biology Lab, Pearl Research Park, SBST, Vellore Institute of Technology, Vellore-632 014, India
| | - Joanna Andrecka
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- Present address: Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Neil Billington
- Laboratory of Molecular Physiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, U.S.A
- Present address: Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV, U.S.A
| | - Gavin Young
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- Present address: Refeyn Ltd., Unit 9, Trade City, Sandy Ln W, Littlemore, Oxford OX4 6FF, U.K
| | - Daniel Cole
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- Present address: Refeyn Ltd., Unit 9, Trade City, Sandy Ln W, Littlemore, Oxford OX4 6FF, U.K
| | - Stan A. Burgess
- Astbury Centre for Structural Molecular Biology, and Institute of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, U.K
| | - Alistair P. Curd
- Astbury Centre for Structural Molecular Biology, and Institute of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, U.K
| | - John A. Hammer
- Cell and Developmental Biology Center, NHLBI, National Institutes of Health, Bethesda, MD 20892, U.S.A
| | - James R. Sellers
- Laboratory of Molecular Physiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, U.S.A
| | - Philipp Kukura
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Rd, Oxford OX1 3QU, U.K
| | - Peter J. Knight
- Astbury Centre for Structural Molecular Biology, and Institute of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, U.K
| |
Collapse
|
10
|
Vitriol EA, Quintanilla MA, Tidei JJ, Troughton LD, Cody A, Cisterna BA, Jane ML, Oakes PW, Beach JR. Non-muscle myosin 2 filaments are processive in cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.24.529920. [PMID: 36865321 PMCID: PMC9980172 DOI: 10.1101/2023.02.24.529920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Directed transport of cellular components is often dependent on the processive movements of cytoskeletal motors. Myosin 2 motors predominantly engage actin filaments of opposing orientation to drive contractile events, and are therefore not traditionally viewed as processive. However, recent in vitro experiments with purified non-muscle myosin 2 (NM2) demonstrated myosin 2 filaments could move processively. Here, we establish processivity as a cellular property of NM2. Processive runs in central nervous system-derived CAD cells are most apparent as processive movements on bundled actin in protrusions that terminate at the leading edge. We find that processive velocities in vivo are consistent with in vitro measurements. NM2 makes these processive runs in its filamentous form against lamellipodia retrograde flow, though anterograde movement can still occur in the absence of actin dynamics. Comparing the processivity of NM2 isoforms, we find that NM2A moves slightly faster than NM2B. Finally, we demonstrate that this is not a cell-specific property, as we observe processive-like movements of NM2 in the lamella and subnuclear stress fibers of fibroblasts. Collectively, these observations further broaden NM2 functionality and the biological processes in which the already ubiquitous motor can contribute.
Collapse
Affiliation(s)
- Eric A Vitriol
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA
| | - Melissa A Quintanilla
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Joseph J Tidei
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Lee D Troughton
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Abigail Cody
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Bruno A Cisterna
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA
| | - Makenzie L Jane
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA
| | - Patrick W Oakes
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Jordan R Beach
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| |
Collapse
|
11
|
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.
Collapse
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.
| |
Collapse
|
12
|
Wang R, Wang Y, Yu R, Xu W, Zhang T, Xiao Y. Case report: Osteo-oto-hepato-enteric syndrome caused by UNC45A deficiency. Front Genet 2023; 13:1079481. [PMID: 36699472 PMCID: PMC9868473 DOI: 10.3389/fgene.2022.1079481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/19/2022] [Indexed: 01/10/2023] Open
Abstract
Background: Recently, UNC45 myosin chaperone A (UNC45A) deficiency was identified as a cause of osteo-oto-hepato-enteric syndrome (O2HE) characterized by congenital diarrhea, neonatal cholestasis, deafness, and bone fragility. To date, only a few O2HE cases have been reported in the literature. Case presentation: Here, we present a child from China diagnosed with O2HE with novel compound heterozygous variants in UNC45A. The patient suffered with neonatal jaundice, cholestasis, and intractable diarrhea after birth. Laboratory tests revealed highly elevated levels of total serum bilirubin (TB), direct bilirubin (DB), and total bile acid (TBA). The patient was managed with ursodeoxycholic acid (UDCA)-based treatments, and the clinical symptoms and abnormal liver functions were significantly relieved. The patient's hearing was normal, and no sign of bone fragility was observed. Exome sequencing (ES) identified novel compound heterozygote variants c.292C>T (p.Arg98Trp)/c.2534-2545del (p.Leu845-Met848del) in UNC45A, which were inherited from her mother and father, respectively. Both variants are predicted to be deleterious by in silico predictors. Conclusion: We present an O2HE child from China with novel compound heterozygous variants in UNC45A. Our patient's clinical manifestations were less severe than those of the previous reported cases, which expands the clinical spectrum of O2HE.
Collapse
Affiliation(s)
- Ruixue Wang
- Department of Gastroenterology, Hepatology, and Nutrition, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yizhong Wang
- Department of Gastroenterology, Hepatology, and Nutrition, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China,Gut Microbiota and Metabolic Research Center, Immunity and Critical Care Medicine, School of Medicine, Institute of Pediatric Infection, Shanghai Jiao Tong University, Shanghai, China
| | - Ronghua Yu
- Department of Gastroenterology, Hepatology, and Nutrition, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wuhen Xu
- Molecular Diagnostic Laboratory, School of Medicine, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Ting Zhang
- Department of Gastroenterology, Hepatology, and Nutrition, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China,Gut Microbiota and Metabolic Research Center, Immunity and Critical Care Medicine, School of Medicine, Institute of Pediatric Infection, Shanghai Jiao Tong University, Shanghai, China
| | - Yongmei Xiao
- Department of Gastroenterology, Hepatology, and Nutrition, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China,*Correspondence: Yongmei Xiao,
| |
Collapse
|
13
|
Fitz GN, Weck ML, Bodnya C, Perkins OL, Tyska MJ. Protrusion growth driven by myosin-generated force. Dev Cell 2023; 58:18-33.e6. [PMID: 36626869 PMCID: PMC9940483 DOI: 10.1016/j.devcel.2022.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/10/2022] [Accepted: 11/29/2022] [Indexed: 01/11/2023]
Abstract
Actin-based protrusions extend from the surface of all eukaryotic cells, where they support diverse activities essential for life. Models of protrusion growth hypothesize that actin filament assembly exerts force for pushing the plasma membrane outward. However, membrane-associated myosin motors are also abundant in protrusions, although their potential for contributing, growth-promoting force remains unexplored. Using an inducible system that docks myosin motor domains to membrane-binding modules with temporal control, we found that application of myosin-generated force to the membrane is sufficient for driving robust protrusion elongation in human, mouse, and pig cell culture models. Protrusion growth scaled with motor accumulation, required barbed-end-directed force, and was independent of cargo delivery or recruitment of canonical elongation factors. Application of growth-promoting force was also supported by structurally distinct myosin motors and membrane-binding modules. Thus, myosin-generated force can drive protrusion growth, and this mechanism is likely active in diverse biological contexts.
Collapse
Affiliation(s)
- Gillian N Fitz
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Meredith L Weck
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Caroline Bodnya
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Olivia L Perkins
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Matthew J Tyska
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| |
Collapse
|
14
|
Moreland ZG, Bird JE. Myosin motors in sensory hair bundle assembly. Curr Opin Cell Biol 2022; 79:102132. [PMID: 36257241 DOI: 10.1016/j.ceb.2022.102132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 09/02/2022] [Accepted: 09/07/2022] [Indexed: 01/31/2023]
Abstract
Mechanosensory hair bundles are assembled from actin-based stereocilia that project from the apical surface of hair cells in the inner ear. Stereocilia architecture is critical for the transduction of sound and accelerations, and structural defects in these mechano-sensors are a clinical cause of hearing and balance disorders in humans. Unconventional myosin motors are central to the assembly and shaping of stereocilia architecture. A sub-group of myosin motors with MyTH4-FERM domains (MYO7A, MYO15A) are particularly important in these processes, and hypothesized to act as transporters delivering structural and actin-regulatory cargos, in addition to generating force and tension. In this review, we summarize existing evidence for how MYO7A and MYO15A operate and how their dysfunction leads to stereocilia pathology. We further highlight emerging properties of the MyTH4/FERM myosin family and speculate how these new functions might contribute towards the acquisition and maintenance of mechano-sensitivity.
Collapse
Affiliation(s)
- Zane G Moreland
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, 32610, USA; Myology Institute, University of Florida, Gainesville, FL, 32610, USA; Graduate Program in Biomedical Sciences, University of Florida, Gainesville, FL, 32610, USA
| | - Jonathan E Bird
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, 32610, USA; Myology Institute, University of Florida, Gainesville, FL, 32610, USA.
| |
Collapse
|
15
|
Analysis of Plasmodium falciparum myosin B ATPase activity and structure in complex with the calmodulin-like domain of its light chain MLC-B. J Biol Chem 2022; 298:102634. [PMID: 36273584 PMCID: PMC9692044 DOI: 10.1016/j.jbc.2022.102634] [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: 05/29/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 11/07/2022] Open
Abstract
Myosin B (MyoB) is a class 14 myosin expressed in all invasive stages of the malaria parasite, Plasmodium falciparum. It is not associated with the glideosome complex that drives motility and invasion of host cells. During red blood cell invasion, MyoB remains at the apical tip of the merozoite but is no longer observed once invasion is completed. MyoB is not essential for parasite survival, but when it is knocked out, merozoites are delayed in the initial stages of red blood cell invasion, giving rise to a growth defect that correlates with reduced invasion success. Therefore, further characterization is needed to understand how MyoB contributes to parasite invasion. Here, we have expressed and purified functional MyoB with the help of parasite-specific chaperones Hsp90 and Unc45, characterized its binding to actin and its known light chain MLC-B using biochemical and biophysical methods and determined its low-resolution structure in solution using small angle X-ray scattering. In addition to MLC-B, we found that four other putative regulatory light chains bind to the MyoB IQ2 motif in vitro. The purified recombinant MyoB adopted the overall shape of a myosin, exhibited actin-activated ATPase activity, and moved actin filaments in vitro. Additionally, we determined that the ADP release rate was faster than the ATP turnover number, and thus, does not appear to be rate limiting. This, together with the observed high affinity to actin and the specific localization of MyoB, may point toward a role in tethering and/or force sensing during early stages of invasion.
Collapse
|
16
|
Gong R, Jiang F, Moreland ZG, Reynolds MJ, de los Reyes SE, Gurel P, Shams A, Heidings JB, Bowl MR, Bird JE, Alushin GM. Structural basis for tunable control of actin dynamics by myosin-15 in mechanosensory stereocilia. SCIENCE ADVANCES 2022; 8:eabl4733. [PMID: 35857845 PMCID: PMC9299544 DOI: 10.1126/sciadv.abl4733] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 06/03/2022] [Indexed: 05/12/2023]
Abstract
The motor protein myosin-15 is necessary for the development and maintenance of mechanosensory stereocilia, and mutations in myosin-15 cause hereditary deafness. In addition to transporting actin regulatory machinery to stereocilia tips, myosin-15 directly nucleates actin filament ("F-actin") assembly, which is disrupted by a progressive hearing loss mutation (p.D1647G, "jordan"). Here, we present cryo-electron microscopy structures of myosin-15 bound to F-actin, providing a framework for interpreting the impacts of deafness mutations on motor activity and actin nucleation. Rigor myosin-15 evokes conformational changes in F-actin yet maintains flexibility in actin's D-loop, which mediates inter-subunit contacts, while the jordan mutant locks the D-loop in a single conformation. Adenosine diphosphate-bound myosin-15 also locks the D-loop, which correspondingly blunts actin-polymerization stimulation. We propose myosin-15 enhances polymerization by bridging actin protomers, regulating nucleation efficiency by modulating actin's structural plasticity in a myosin nucleotide state-dependent manner. This tunable regulation of actin polymerization could be harnessed to precisely control stereocilium height.
Collapse
Affiliation(s)
- Rui Gong
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | - Fangfang Jiang
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Zane G. Moreland
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Matthew J. Reynolds
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | | | - Pinar Gurel
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | - Arik Shams
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - James B. Heidings
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Michael R. Bowl
- Mammalian Genetics Unit, MRC Harwell Institute, Harwell Campus, Oxfordshire, UK
- UCL Ear Institute, University College London, London, UK
| | - Jonathan E. Bird
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Gregory M. Alushin
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| |
Collapse
|
17
|
Kage F, Vicente-Manzanares M, McEwan BC, Kettenbach AN, Higgs HN. Myosin II proteins are required for organization of calcium-induced actin networks upstream of mitochondrial division. Mol Biol Cell 2022; 33:ar63. [PMID: 35427150 PMCID: PMC9561854 DOI: 10.1091/mbc.e22-01-0005] [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] [Indexed: 11/11/2022] Open
Abstract
The formin INF2 polymerizes a calcium-activated cytoplasmic network of actin filaments, which we refer to as calcium-induced actin polymerization (CIA). CIA plays important roles in multiple cellular processes, including mitochondrial dynamics and vesicle transport. Here, we show that nonmuscle myosin II (NMII) is activated within 60 s of calcium stimulation and rapidly recruited to the CIA network. Knockout of any individual NMII in U2OS cells affects the organization of the CIA network, as well as three downstream effects: endoplasmic-reticulum-to-mitochondrial calcium transfer, mitochondrial Drp1 recruitment, and mitochondrial division. Interestingly, while NMIIC is the least abundant NMII in U2OS cells (>200-fold less than NMIIA and >10-fold less than NMIIB), its knockout is equally deleterious to CIA. On the basis of these results, we propose that myosin II filaments containing all three NMII heavy chains exert organizational and contractile roles in the CIA network. In addition, NMIIA knockout causes a significant decrease in myosin regulatory light chain levels, which might have additional effects.
Collapse
Affiliation(s)
- Frieda Kage
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Miguel Vicente-Manzanares
- Centro de Investigacion del Cancer/Instituto de Biologia Molecular y Celular del Cancer, Centro Mixto Universidad de Salamanca, 37007 Salamanca, Spain
| | - Brennan C. McEwan
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
- Program in Cancer Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Arminja N. Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
- Program in Cancer Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Henry N. Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| |
Collapse
|
18
|
Miyoshi T, Belyantseva IA, Kitajiri SI, Miyajima H, Nishio SY, Usami SI, Kim BJ, Choi BY, Omori K, Shroff H, Friedman TB. Human deafness-associated variants alter the dynamics of key molecules in hair cell stereocilia F-actin cores. Hum Genet 2021; 141:363-382. [PMID: 34232383 DOI: 10.1007/s00439-021-02304-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/15/2021] [Indexed: 12/16/2022]
Abstract
Stereocilia protrude up to 100 µm from the apical surface of vertebrate inner ear hair cells and are packed with cross-linked filamentous actin (F-actin). They function as mechanical switches to convert sound vibration into electrochemical neuronal signals transmitted to the brain. Several genes encode molecular components of stereocilia including actin monomers, actin regulatory and bundling proteins, motor proteins and the proteins of the mechanotransduction complex. A stereocilium F-actin core is a dynamic system, which is continuously being remodeled while maintaining an outwardly stable architecture under the regulation of F-actin barbed-end cappers, severing proteins and crosslinkers. The F-actin cores of stereocilia also provide a pathway for motor proteins to transport cargos including components of tip-link densities, scaffolding proteins and actin regulatory proteins. Deficiencies and mutations of stereocilia components that disturb this "dynamic equilibrium" in stereocilia can induce morphological changes and disrupt mechanotransduction causing sensorineural hearing loss, best studied in mouse and zebrafish models. Currently, at least 23 genes, associated with human syndromic and nonsyndromic hearing loss, encode proteins involved in the development and maintenance of stereocilia F-actin cores. However, it is challenging to predict how variants associated with sensorineural hearing loss segregating in families affect protein function. Here, we review the functions of several molecular components of stereocilia F-actin cores and provide new data from our experimental approach to directly evaluate the pathogenicity and functional impact of reported and novel variants of DIAPH1 in autosomal-dominant DFNA1 hearing loss using single-molecule fluorescence microscopy.
Collapse
Affiliation(s)
- Takushi Miyoshi
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, Room 1F-143A, Bethesda, MD, 20892, USA. .,Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan.
| | - Inna A Belyantseva
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, Room 1F-143A, Bethesda, MD, 20892, USA
| | - Shin-Ichiro Kitajiri
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 390-8621, Matsumoto, Japan
| | - Hiroki Miyajima
- Department of Otolaryngology, Shinshu University School of Medicine, Matsumoto, 390-8621, Japan.,Department of Otolaryngology, Aizawa Hospital, Matsumoto, 390-8510, Japan
| | - Shin-Ya Nishio
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 390-8621, Matsumoto, Japan
| | - Shin-Ichi Usami
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 390-8621, Matsumoto, Japan
| | - Bong Jik Kim
- Department of Otolaryngology-Head and Neck Surgery, Chungnam National University College of Medicine, Chungnam National University Sejong Hospital, Sejong, 30099, South Korea.,Brain Research Institute, Chungnam National University College of Medicine, Daejeon, 35015, South Korea
| | - Byung Yoon Choi
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, 13620, South Korea
| | - Koichi Omori
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Hari Shroff
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, Room 1F-143A, Bethesda, MD, 20892, USA
| |
Collapse
|
19
|
Latham SL, Weiß N, Schwanke K, Thiel C, Croucher DR, Zweigerdt R, Manstein DJ, Taft MH. Myosin-18B Regulates Higher-Order Organization of the Cardiac Sarcomere through Thin Filament Cross-Linking and Thick Filament Dynamics. Cell Rep 2021; 32:108090. [PMID: 32877672 DOI: 10.1016/j.celrep.2020.108090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/07/2020] [Accepted: 08/07/2020] [Indexed: 12/20/2022] Open
Abstract
MYO18B loss-of-function mutations and depletion significantly compromise the structural integrity of striated muscle sarcomeres. The molecular function of the encoded protein, myosin-18B (M18B), within the developing muscle is unknown. Here, we demonstrate that recombinant M18B lacks motor ATPase activity and harbors previously uncharacterized N-terminal actin-binding domains, properties that make M18B an efficient actin cross-linker and molecular brake capable of regulating muscle myosin-2 contractile forces. Spatiotemporal analysis of M18B throughout cardiomyogenesis and myofibrillogenesis reveals that this structural myosin undergoes nuclear-cytoplasmic redistribution during myogenic differentiation, where its incorporation within muscle stress fibers coincides with actin striation onset. Furthermore, this analysis shows that M18B is directly integrated within the muscle myosin thick filament during myofibril maturation. Altogether, our data suggest that M18B has evolved specific biochemical properties that allow it to define and maintain sarcomeric organization from within the thick filament via its dual actin cross-linking and motor modulating capabilities.
Collapse
Affiliation(s)
- Sharissa L Latham
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover 30625, Germany; The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia; St Vincent's Hospital Clinical School, UNSW Sydney, NSW 2052, Australia
| | - Nadine Weiß
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover 30625, Germany
| | - Kristin Schwanke
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, REBIRTH-Cluster of Excellence, Hannover Medical School, Hannover 30625, Germany
| | - Claudia Thiel
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover 30625, Germany
| | - David R Croucher
- The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia; St Vincent's Hospital Clinical School, UNSW Sydney, NSW 2052, Australia
| | - Robert Zweigerdt
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, REBIRTH-Cluster of Excellence, Hannover Medical School, Hannover 30625, Germany
| | - Dietmar J Manstein
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover 30625, Germany
| | - Manuel H Taft
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover 30625, Germany.
| |
Collapse
|
20
|
Abstract
Filopodia, microvilli and stereocilia represent an important group of plasma membrane protrusions. These specialized projections are supported by parallel bundles of actin filaments and have critical roles in sensing the external environment, increasing cell surface area, and acting as mechanosensors. While actin-associated proteins are essential for actin-filament elongation and bundling in these protrusions, myosin motors have a surprising role in the formation and extension of filopodia and stereocilia and in the organization of microvilli. Actin regulators and specific myosins collaborate in controlling the length of these structures. Myosins can transport cargoes along the length of these protrusions, and, in the case of stereocilia and microvilli, interactions with adaptors and cargoes can also serve to anchor adhesion receptors to the actin-rich core via functionally conserved motor-adaptor complexes. This review highlights recent progress in understanding the diverse roles myosins play in filopodia, microvilli and stereocilia.
Collapse
Affiliation(s)
- Anne Houdusse
- Structural Motility, Institut Curie, Paris Université Sciences et Lettres, Sorbonne Université, CNRS UMR144, 75005 Paris, France.
| | - Margaret A Titus
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA.
| |
Collapse
|
21
|
Rich SK, Baskar R, Terman JR. Propagation of F-actin disassembly via Myosin15-Mical interactions. SCIENCE ADVANCES 2021; 7:7/20/eabg0147. [PMID: 33980493 PMCID: PMC8115926 DOI: 10.1126/sciadv.abg0147] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
The F-actin cytoskeleton drives cellular form and function. However, how F-actin-based changes occur with spatiotemporal precision and specific directional orientation is poorly understood. Here, we identify that the unconventional class XV myosin [Myosin 15 (Myo15)] physically and functionally interacts with the F-actin disassembly enzyme Mical to spatiotemporally position cellular breakdown and reconstruction. Specifically, while unconventional myosins have been associated with transporting cargo along F-actin to spatially target cytoskeletal assembly, we now find they also target disassembly. Myo15 specifically positions this F-actin disassembly by associating with Mical and using its motor and MyTH4-FERM cargo-transporting functions to broaden Mical's distribution. Myo15's broadening of Mical's distribution also expands and directionally orients Mical-mediated F-actin disassembly and subsequent cellular remodeling, including in response to Semaphorin/Plexin cell surface activation signals. Thus, we identify a mechanism that spatiotemporally propagates F-actin disassembly while also proposing that other F-actin-trafficked-cargo is derailed by this disassembly to directionally orient rebuilding.
Collapse
Affiliation(s)
- Shannon K Rich
- Departments of Neuroscience and Pharmacology and Neuroscience Graduate Program, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Raju Baskar
- Departments of Neuroscience and Pharmacology and Neuroscience Graduate Program, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jonathan R Terman
- Departments of Neuroscience and Pharmacology and Neuroscience Graduate Program, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
22
|
Cirilo JA, Gunther LK, Yengo CM. Functional Role of Class III Myosins in Hair Cells. Front Cell Dev Biol 2021; 9:643856. [PMID: 33718386 PMCID: PMC7947357 DOI: 10.3389/fcell.2021.643856] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/01/2021] [Indexed: 11/14/2022] Open
Abstract
Cytoskeletal motors produce force and motion using the energy from ATP hydrolysis and function in a variety of mechanical roles in cells including muscle contraction, cargo transport, and cell division. Actin-based myosin motors have been shown to play crucial roles in the development and function of the stereocilia of auditory and vestibular inner ear hair cells. Hair cells can contain hundreds of stereocilia, which rely on myosin motors to elongate, organize, and stabilize their structure. Mutations in many stereocilia-associated myosins have been shown to cause hearing loss in both humans and animal models suggesting that each myosin isoform has a specific function in these unique parallel actin bundle-based protrusions. Here we review what is known about the classes of myosins that function in the stereocilia, with a special focus on class III myosins that harbor point mutations associated with delayed onset hearing loss. Much has been learned about the role of the two class III myosin isoforms, MYO3A and MYO3B, in maintaining the precise stereocilia lengths required for normal hearing. We propose a model for how class III myosins play a key role in regulating stereocilia lengths and demonstrate how their motor and regulatory properties are particularly well suited for this function. We conclude that ongoing studies on class III myosins and other stereocilia-associated myosins are extremely important and may lead to novel therapeutic strategies for the treatment of hearing loss due to stereocilia degeneration.
Collapse
Affiliation(s)
- Joseph A Cirilo
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, United States
| | - Laura K Gunther
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, United States
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, United States
| |
Collapse
|
23
|
Jiang F, Takagi Y, Shams A, Heissler SM, Friedman TB, Sellers JR, Bird JE. The ATPase mechanism of myosin 15, the molecular motor mutated in DFNB3 human deafness. J Biol Chem 2021; 296:100243. [PMID: 33372036 PMCID: PMC7948958 DOI: 10.1074/jbc.ra120.014903] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 11/18/2022] Open
Abstract
Cochlear hair cells each possess an exquisite bundle of actin-based stereocilia that detect sound. Unconventional myosin 15 (MYO15) traffics and delivers critical molecules required for stereocilia development and thus is essential for building the mechanosensory hair bundle. Mutations in the human MYO15A gene interfere with stereocilia trafficking and cause hereditary hearing loss, DFNB3, but the impact of these mutations is not known, as MYO15 itself is poorly characterized. To learn more, we performed a kinetic study of the ATPase motor domain to characterize its mechanochemical cycle. Using the baculovirus-Sf9 system, we purified a recombinant minimal motor domain (S1) by coexpressing the mouse MYO15 ATPase, essential and regulatory light chains that bind its IQ domains, and UNC45 and HSP90A chaperones required for correct folding of the ATPase. MYO15 purified with either UNC45A or UNC45B coexpression had similar ATPase activities (kcat = ∼ 6 s-1 at 20 °C). Using stopped-flow and quenched-flow transient kinetic analyses, we measured the major rate constants describing the ATPase cycle, including ATP, ADP, and actin binding; hydrolysis; and phosphate release. Actin-attached ADP release was the slowest measured transition (∼12 s-1 at 20 °C), although this did not rate-limit the ATPase cycle. The kinetic analysis shows the MYO15 motor domain has a moderate duty ratio (∼0.5) and weak thermodynamic coupling between ADP and actin binding. These findings are consistent with MYO15 being kinetically adapted for processive motility when oligomerized. Our kinetic characterization enables future studies into how deafness-causing mutations affect MYO15 and disrupt stereocilia trafficking necessary for hearing.
Collapse
Affiliation(s)
- Fangfang Jiang
- Department of Pharmacology and Therapeutics, and the Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Yasuharu Takagi
- Laboratory of Molecular Physiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Arik Shams
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, USA
| | - Sarah M Heissler
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, USA
| | - James R Sellers
- Laboratory of Molecular Physiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Jonathan E Bird
- Department of Pharmacology and Therapeutics, and the Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA.
| |
Collapse
|
24
|
Myosin XVI in the Nervous System. Cells 2020; 9:cells9081903. [PMID: 32824179 PMCID: PMC7464383 DOI: 10.3390/cells9081903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/07/2020] [Accepted: 08/12/2020] [Indexed: 12/12/2022] Open
Abstract
The myosin family is a large inventory of actin-associated motor proteins that participate in a diverse array of cellular functions. Several myosin classes are expressed in neural cells and play important roles in neural functioning. A recently discovered member of the myosin superfamily, the vertebrate-specific myosin XVI (Myo16) class is expressed predominantly in neural tissues and appears to be involved in the development and proper functioning of the nervous system. Accordingly, the alterations of MYO16 has been linked to neurological disorders. Although the role of Myo16 as a generic actin-associated motor is still enigmatic, the N-, and C-terminal extensions that flank the motor domain seem to confer unique structural features and versatile interactions to the protein. Recent biochemical and physiological examinations portray Myo16 as a signal transduction element that integrates cell signaling pathways to actin cytoskeleton reorganization. This review discusses the current knowledge of the structure-function relation of Myo16. In light of its prevalent localization, the emphasis is laid on the neural aspects.
Collapse
|
25
|
Abstract
Myosins constitute a superfamily of actin-based molecular motor proteins that mediates a variety of cellular activities including muscle contraction, cell migration, intracellular transport, the formation of membrane projections, cell adhesion, and cell signaling. The 12 myosin classes that are expressed in humans share sequence similarities especially in the N-terminal motor domain; however, their enzymatic activities, regulation, ability to dimerize, binding partners, and cellular functions differ. It is becoming increasingly apparent that defects in myosins are associated with diseases including cardiomyopathies, colitis, glomerulosclerosis, neurological defects, cancer, blindness, and deafness. Here, we review the current state of knowledge regarding myosins and disease.
Collapse
|
26
|
|
27
|
Caldwell JT, Mermelstein DJ, Walker RC, Bernstein SI, Huxford T. X-ray Crystallographic and Molecular Dynamic Analyses of Drosophila melanogaster Embryonic Muscle Myosin Define Domains Responsible for Isoform-Specific Properties. J Mol Biol 2020; 432:427-447. [PMID: 31786266 PMCID: PMC6995774 DOI: 10.1016/j.jmb.2019.11.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/19/2019] [Accepted: 11/19/2019] [Indexed: 01/19/2023]
Abstract
Drosophila melanogaster is a powerful system for characterizing alternative myosin isoforms and modeling muscle diseases, but high-resolution structures of fruit fly contractile proteins have not been determined. Here we report the first x-ray crystal structure of an insect myosin: the D melanogaster skeletal muscle myosin II embryonic isoform (EMB). Using our system for recombinant expression of myosin heavy chain (MHC) proteins in whole transgenic flies, we prepared and crystallized stable proteolytic S1-like fragments containing the entire EMB motor domain bound to an essential light chain. We solved the x-ray crystal structure by molecular replacement and refined the resulting model against diffraction data to 2.2 Å resolution. The protein is captured in two slightly different renditions of the rigor-like conformation with a citrate of crystallization at the nucleotide binding site and exhibits structural features common to myosins of diverse classes from all kingdoms of life. All atom molecular dynamics simulations on EMB in its nucleotide-free state and a derivative homology model containing 61 amino acid substitutions unique to the indirect flight muscle isoform (IFI) suggest that differences in the identity of residues within the relay and the converter that are encoded for by MHC alternative exons 9 and 11, respectively, directly contribute to increased mobility of these regions in IFI relative to EMB. This suggests the possibility that alternative folding or conformational stability within these regions contribute to the observed functional differences in Drosophila EMB and IFI myosins.
Collapse
Affiliation(s)
- James T Caldwell
- Structural Biochemistry Laboratory, Department of Chemistry & Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1030, USA; Department of Biology and Molecular Biology Institute, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4614, USA
| | - Daniel J Mermelstein
- San Diego Supercomputer Center and Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0505, USA
| | - Ross C Walker
- San Diego Supercomputer Center and Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0505, USA
| | - Sanford I Bernstein
- Department of Biology and Molecular Biology Institute, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4614, USA
| | - Tom Huxford
- Structural Biochemistry Laboratory, Department of Chemistry & Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1030, USA.
| |
Collapse
|
28
|
Mechanotransduction-Dependent Control of Stereocilia Dimensions and Row Identity in Inner Hair Cells. Curr Biol 2020; 30:442-454.e7. [PMID: 31902726 DOI: 10.1016/j.cub.2019.11.076] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/08/2019] [Accepted: 11/26/2019] [Indexed: 02/07/2023]
Abstract
Actin-rich structures, like stereocilia and microvilli, are assembled with precise control of length, diameter, and relative spacing. By quantifying actin-core dimensions of stereocilia from phalloidin-labeled mouse cochleas, we demonstrated that inner hair cell stereocilia developed in specific stages, where a widening phase is sandwiched between two lengthening phases. Moreover, widening of the second-tallest stereocilia rank (row 2) occurred simultaneously with the appearance of mechanotransduction. Correspondingly, Tmc1KO/KO;Tmc2KO/KO or TmieKO/KO hair cells, which lack transduction, have significantly altered stereocilia lengths and diameters, including a narrowed row 2. EPS8 and the short splice isoform of MYO15A, identity markers for mature row 1 (the tallest row), lost their row exclusivity in transduction mutants. GNAI3, another member of the mature row 1 complex, accumulated at mutant row 1 tips at considerably lower levels than in wild-type bundles. Alterations in stereocilia dimensions and in EPS8 distribution seen in transduction mutants were mimicked by block of transduction channels of cochlear explants in culture. In addition, proteins normally concentrated at mature row 2 tips were also distributed differently in transduction mutants; the heterodimeric capping protein subunit CAPZB and its partner TWF2 never concentrated at row 2 tips like they do in wild-type bundles. The altered distribution of marker proteins in transduction mutants was accompanied by increased variability in stereocilia length. Transduction channels thus specify and maintain row identity, control addition of new actin filaments to increase stereocilia diameter, and coordinate stereocilia height within rows.
Collapse
|
29
|
Friedman TB, Belyantseva IA, Frolenkov GI. Myosins and Hearing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1239:317-330. [DOI: 10.1007/978-3-030-38062-5_13] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
30
|
Hellerschmied D, Lehner A, Franicevic N, Arnese R, Johnson C, Vogel A, Meinhart A, Kurzbauer R, Deszcz L, Gazda L, Geeves M, Clausen T. Molecular features of the UNC-45 chaperone critical for binding and folding muscle myosin. Nat Commun 2019; 10:4781. [PMID: 31636255 PMCID: PMC6803673 DOI: 10.1038/s41467-019-12667-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 09/21/2019] [Indexed: 12/16/2022] Open
Abstract
Myosin is a motor protein that is essential for a variety of processes ranging from intracellular transport to muscle contraction. Folding and assembly of myosin relies on a specific chaperone, UNC-45. To address its substrate-targeting mechanism, we reconstitute the interplay between Caenorhabditis elegans UNC-45 and muscle myosin MHC-B in insect cells. In addition to providing a cellular chaperone assay, the established system enabled us to produce large amounts of functional muscle myosin, as evidenced by a biochemical and structural characterization, and to directly monitor substrate binding to UNC-45. Data from in vitro and cellular chaperone assays, together with crystal structures of binding-deficient UNC-45 mutants, highlight the importance of utilizing a flexible myosin-binding domain. This so-called UCS domain can adopt discrete conformations to efficiently bind and fold substrate. Moreover, our data uncover the molecular basis of temperature-sensitive UNC-45 mutations underlying one of the most prominent motility defects in C. elegans. Myosin, a motor protein essential for intracellular transport to muscle contraction, requires a chaperone UNC-45 for folding and assembly. Here authors use in vitro reconstitution and structural biology to characterize the interplay between UNC-45 and muscle myosin MHC-B.
Collapse
Affiliation(s)
- Doris Hellerschmied
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria. .,Faculty of Biology, Center of Medical Biotechnology, University Duisburg-Essen, Essen, Germany.
| | | | - Nina Franicevic
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Renato Arnese
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Chloe Johnson
- School of Biosciences, University of Kent, Canterbury, UK
| | - Antonia Vogel
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Anton Meinhart
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Robert Kurzbauer
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Luiza Deszcz
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Linn Gazda
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Michael Geeves
- School of Biosciences, University of Kent, Canterbury, UK
| | - Tim Clausen
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria. .,Medical University Vienna, Vienna, Austria.
| |
Collapse
|
31
|
Mooneyham A, Iizuka Y, Yang Q, Coombes C, McClellan M, Shridhar V, Emmings E, Shetty M, Chen L, Ai T, Meints J, Lee MK, Gardner M, Bazzaro M. UNC-45A Is a Novel Microtubule-Associated Protein and Regulator of Paclitaxel Sensitivity in Ovarian Cancer Cells. Mol Cancer Res 2019; 17:370-383. [PMID: 30322860 PMCID: PMC6359974 DOI: 10.1158/1541-7786.mcr-18-0670] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 09/11/2018] [Accepted: 10/02/2018] [Indexed: 12/14/2022]
Abstract
UNC-45A, a highly conserved member of the UCS (UNC45A/CRO1/SHE4P) protein family of cochaperones, plays an important role in regulating cytoskeletal-associated functions in invertebrates and mammalian cells, including cytokinesis, exocytosis, cell motility, and neuronal development. Here, for the first time, UNC-45A is demonstrated to function as a mitotic spindle-associated protein that destabilizes microtubules (MT) activity. Using in vitro biophysical reconstitution and total internal reflection fluorescence microscopy analysis, we reveal that UNC-45A directly binds to taxol-stabilized MTs in the absence of any additional cellular cofactors or other MT-associated proteins and acts as an ATP-independent MT destabilizer. In cells, UNC-45A binds to and destabilizes mitotic spindles, and its depletion causes severe defects in chromosome congression and segregation. UNC-45A is overexpressed in human clinical specimens from chemoresistant ovarian cancer and that UNC-45A-overexpressing cells resist chromosome missegregation and aneuploidy when treated with clinically relevant concentrations of paclitaxel. Lastly, UNC-45A depletion exacerbates paclitaxel-mediated stabilizing effects on mitotic spindles and restores sensitivity to paclitaxel. IMPLICATIONS: These findings reveal novel and significant roles for UNC-45A in regulation of cytoskeletal dynamics, broadening our understanding of the basic mechanisms regulating MT stability and human cancer susceptibility to paclitaxel, one of the most widely used chemotherapy agents for the treatment of human cancers.
Collapse
Affiliation(s)
- Ashley Mooneyham
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Heath, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yoshie Iizuka
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Heath, University of Minnesota, Minneapolis, MN 55455, USA
| | - Qing Yang
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455
| | - Courtney Coombes
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455
| | - Mark McClellan
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455
| | - Vijayalakshmi Shridhar
- Department of Experimental Pathology, Mayo Clinic College of Medicine, Rochester, MN 55905 USA
| | - Edith Emmings
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Heath, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mihir Shetty
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Heath, University of Minnesota, Minneapolis, MN 55455, USA
| | - Liqiang Chen
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455 USA
| | - Teng Ai
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455 USA
| | - Joyce Meints
- Department of Neuroscience, University of Minnesota Minneapolis, MN 55455 USA
| | - Michael K Lee
- Department of Neuroscience, University of Minnesota Minneapolis, MN 55455 USA
| | - Melissa Gardner
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455
| | - Martina Bazzaro
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women’s Heath, University of Minnesota, Minneapolis, MN 55455, USA,,Corresponding author: Martina Bazzaro, Masonic Cancer Center, 420 Delaware Street S.E, Room 490, Minneapolis, Minnesota 55455, Tel: 612-6252889, Fax: 612-626-0665,
| |
Collapse
|
32
|
Wollenberg RD, Taft MH, Giese S, Thiel C, Balázs Z, Giese H, Manstein DJ, Sondergaard TE. Phenamacril is a reversible and noncompetitive inhibitor of Fusarium class I myosin. J Biol Chem 2019; 294:1328-1337. [PMID: 30504222 PMCID: PMC6349130 DOI: 10.1074/jbc.ra118.005408] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/01/2018] [Indexed: 01/03/2023] Open
Abstract
The cyanoacrylate compound phenamacril (also known as JS399-19) is a recently identified fungicide that exerts its antifungal effect on susceptible Fusarium species by inhibiting the ATPase activity of their myosin class I motor domains. Although much is known about the antifungal spectrum of phenamacril, the exact mechanism behind the phenamacril-mediated inhibition remains to be resolved. Here, we describe the characterization of the effect of phenamacril on purified myosin motor constructs from the model plant pathogen and phenamacril-susceptible species Fusarium graminearum, phenamacril-resistant Fusarium species, and the mycetozoan model organism Dictyostelium discoideum Our results show that phenamacril potently (IC50 ∼360 nm), reversibly, and noncompetitively inhibits ATP turnover, actin binding during ATP turnover, and motor activity of F. graminearum myosin-1. Phenamacril also inhibits the ATPase activity of Fusarium avenaceum myosin-1 but has little or no inhibitory effect on the motor activity of Fusarium solani myosin-1, human myosin-1c, and D. discoideum myosin isoforms 1B, 1E, and 2. Our findings indicate that phenamacril is a species-specific, noncompetitive inhibitor of class I myosin in susceptible Fusarium sp.
Collapse
Affiliation(s)
- Rasmus D Wollenberg
- Department of Chemistry and Bioscience, Aalborg University, DK-9220 Aalborg, Denmark
| | - Manuel H Taft
- Institute for Biophysical Chemistry, OE4350, Hannover Medical School, 30623 Hannover, Germany
| | - Sven Giese
- Institute for Biophysical Chemistry, OE4350, Hannover Medical School, 30623 Hannover, Germany
| | - Claudia Thiel
- Division of Structural Biochemistry, OE8830, Hannover Medical School, 30623 Hannover, Germany
| | - Zoltán Balázs
- Department of Chemistry and Bioscience, Aalborg University, DK-9220 Aalborg, Denmark
| | - Henriette Giese
- Department of Chemistry and Bioscience, Aalborg University, DK-9220 Aalborg, Denmark
| | - Dietmar J Manstein
- Institute for Biophysical Chemistry, OE4350, Hannover Medical School, 30623 Hannover, Germany; Division of Structural Biochemistry, OE8830, Hannover Medical School, 30623 Hannover, Germany.
| | - Teis E Sondergaard
- Department of Chemistry and Bioscience, Aalborg University, DK-9220 Aalborg, Denmark.
| |
Collapse
|
33
|
Dash B, Dib-Hajj SD, Waxman SG. Multiple myosin motors interact with sodium/potassium-ATPase alpha 1 subunits. Mol Brain 2018; 11:45. [PMID: 30086768 PMCID: PMC6081954 DOI: 10.1186/s13041-018-0388-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/20/2018] [Indexed: 11/10/2022] Open
Abstract
The alpha1 (α1) subunit of the sodium/potassium ATPase (i.e., Na+/K+-ATPase α1), the prototypical sodium pump, is expressed in each eukaryotic cell. They pump out three sodium ions in exchange for two extracellular potassium ions to establish a cellular electrochemical gradient important for firing of neuronal and cardiac action potentials. We hypothesized that myosin (myo or myh) motor proteins might interact with Na+/K+-ATPase α1 subunits in order for them to play an important role in the transport and trafficking of sodium pump. To this end immunoassays were performed to determine whether class II non-muscle myosins (i.e., NMHC-IIA/myh9, NMHC-IIB/myh10 or NMHC-IIC/myh14), myosin Va (myoVa) and myosin VI (myoVI) would interact with Na+/K+-ATPase α1 subunits. Immunoprecipitation of myh9, myh10, myh14, myoVa and myoVI from rat brain tissues led to the co-immunoprecipitation of Na+/K+-ATPase α1 subunits expressed there. Heterologous expression studies using HEK293 cells indicated that recombinant myh9, myh10, myh14 and myoVI interact with Na+/K+-ATPase α1 subunits expressed in HEK293 cells. Additional results indicated that loss of tail regions in recombinant myh9, myh10, myh14 and myoVI did not affect their interaction with Na+/K+-ATPase α1 subunits. However, recombinant myh9, myh10 and myh14 mutants having reduced or no actin binding ability, as a result of loss of their actin binding sites, displayed greatly reduced or null interaction with Na+/K+-ATPase α1 subunits. These results suggested the involvement of the actin binding site, but not tail regions, of NMHC-IIs in their interaction with Na+/K+-ATPase α1 subunits. Overall these results suggest a role for these diverse myosins in the trafficking and transport of sodium pump in neuronal and non-neuronal tissues.
Collapse
Affiliation(s)
- Bhagirathi Dash
- Department of Neurology, Yale University Schoolof Medicine, New Haven, CT, 06510, USA.,Center for Neuroscience & Regeneration Research, Yale University School of Medicine, New Haven, CT, 06510, USA.,Rehabilitation Research center, VA Connecticut Healthcare System, 950 Campbell Avenue, Bldg. 34, West Haven, CT, 06516, USA
| | - Sulayman D Dib-Hajj
- Department of Neurology, Yale University Schoolof Medicine, New Haven, CT, 06510, USA.,Center for Neuroscience & Regeneration Research, Yale University School of Medicine, New Haven, CT, 06510, USA.,Rehabilitation Research center, VA Connecticut Healthcare System, 950 Campbell Avenue, Bldg. 34, West Haven, CT, 06516, USA
| | - Stephen G Waxman
- Department of Neurology, Yale University Schoolof Medicine, New Haven, CT, 06510, USA. .,Center for Neuroscience & Regeneration Research, Yale University School of Medicine, New Haven, CT, 06510, USA. .,Rehabilitation Research center, VA Connecticut Healthcare System, 950 Campbell Avenue, Bldg. 34, West Haven, CT, 06516, USA.
| |
Collapse
|
34
|
|
35
|
Dash B, Han C, Waxman SG, Dib-Hajj SD. Nonmuscle myosin II isoforms interact with sodium channel alpha subunits. Mol Pain 2018; 14:1744806918788638. [PMID: 29956586 PMCID: PMC6052497 DOI: 10.1177/1744806918788638] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Sodium channels play pivotal roles in health and diseases due to their ability to control cellular excitability. The pore-forming α-subunits (sodium channel alpha subunits) of the voltage-sensitive channels (i.e., Nav1.1–1.9) and the nonvoltage-dependent channel (i.e., Nax) share a common structural motif and selectivity for sodium ions. We hypothesized that the actin-based nonmuscle myosin II motor proteins, nonmuscle myosin heavy chain-IIA/myh9, and nonmuscle myosin heavy chain-IIB/myh10 might interact with sodium channel alpha subunits to play an important role in their transport, trafficking, and/or function. Immunochemical and electrophysiological assays were conducted using rodent nervous (brain and dorsal root ganglia) tissues and ND7/23 cells coexpressing Nav subunits and recombinant myosins. Immunoprecipitation of myh9 and myh10 from rodent brain tissues led to the coimmunoprecipitation of Nax, Nav1.2, and Nav1.3 subunits, but not Nav1.1 and Nav1.6 subunits, expressed there. Similarly, immunoprecipitation of myh9 and myh10 from rodent dorsal root ganglia tissues led to the coimmunoprecipitation of Nav1.7 and Nav1.8 subunits, but not Nav1.9 subunits, expressed there. The functional implication of one of these interactions was assessed by coexpressing myh10 along with Nav1.8 subunits in ND7/23 cells. Myh10 overexpression led to three-fold increase (P < 0.01) in the current density of Nav1.8 channels expressed in ND7/23 cells. Myh10 coexpression also hyperpolarized voltage-dependent activation and steady-state fast inactivation of Nav1.8 channels. In addition, coexpression of myh10 reduced (P < 0.01) the offset of fast inactivation and the amplitude of the ramp currents of Nav1.8 channels. These results indicate that nonmuscle myosin heavy chain-IIs interact with sodium channel alpha subunits subunits in an isoform-dependent manner and influence their functional properties.
Collapse
Affiliation(s)
- Bhagirathi Dash
- 1 Department of Neurology, Yale University School of Medicine, New Haven, CT, USA.,2 Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA.,3 Rehabilitation Research Center, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Chongyang Han
- 1 Department of Neurology, Yale University School of Medicine, New Haven, CT, USA.,2 Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA.,3 Rehabilitation Research Center, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Stephen G Waxman
- 1 Department of Neurology, Yale University School of Medicine, New Haven, CT, USA.,2 Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA.,3 Rehabilitation Research Center, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Sulayman D Dib-Hajj
- 1 Department of Neurology, Yale University School of Medicine, New Haven, CT, USA.,2 Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA.,3 Rehabilitation Research Center, VA Connecticut Healthcare System, West Haven, CT, USA
| |
Collapse
|
36
|
Abstract
The delivery of intracellular material within cells is crucial for maintaining normal function. Myosins transport a wide variety of cargo, ranging from vesicles to ribonuclear protein particles (RNPs), in plants, fungi, and metazoa. The properties of a given myosin transporter are adapted to move on different actin filament tracks, either on the disordered actin networks at the cell cortex or along highly organized actin bundles to distribute their cargo in a localized manner or move it across long distances in the cell. Transport is controlled by selective recruitment of the myosin to its cargo that also plays a role in activation of the motor.
Collapse
Affiliation(s)
- Margaret A Titus
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| |
Collapse
|
37
|
Membrane bending occurs at all stages of clathrin-coat assembly and defines endocytic dynamics. Nat Commun 2018; 9:419. [PMID: 29379015 PMCID: PMC5789089 DOI: 10.1038/s41467-018-02818-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/02/2018] [Indexed: 01/01/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) internalizes plasma membrane by reshaping small regions of the cell surface into spherical vesicles. The key mechanistic question of how coat assembly produces membrane curvature has been studied with molecular and cellular structural biology approaches, without direct visualization of the process in living cells; resulting in two competing models for membrane bending. Here we use polarized total internal reflection fluorescence microscopy (pol-TIRF) combined with electron, atomic force, and super-resolution optical microscopy to measure membrane curvature during CME. Surprisingly, coat assembly accommodates membrane bending concurrent with or after the assembly of the clathrin lattice. Once curvature began, CME proceeded to scission with robust timing. Four color pol-TIRF showed that CALM accumulated at high levels during membrane bending, implicating its auxiliary role in curvature generation. We conclude that clathrin-coat assembly is versatile and that multiple membrane-bending trajectories likely reflect the energetics of coat assembly relative to competing forces. Two distinct and opposing models for clathrin-mediated endocytosis have been inferred from EM and structural biology data. Here the authors develop an optical method to directly visualize membrane-bending dynamics and show that coat assembly accommodates membrane bending during or after the assembly of the clathrin lattice, which is not predicted by either model.
Collapse
|
38
|
Lehtimäki JI, Fenix AM, Kotila TM, Balistreri G, Paavolainen L, Varjosalo M, Burnette DT, Lappalainen P. UNC-45a promotes myosin folding and stress fiber assembly. J Cell Biol 2017; 216:4053-4072. [PMID: 29055011 PMCID: PMC5716280 DOI: 10.1083/jcb.201703107] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 08/28/2017] [Accepted: 09/19/2017] [Indexed: 12/15/2022] Open
Abstract
Contractile actomyosin bundles, stress fibers, are crucial for adhesion, morphogenesis, and mechanosensing in nonmuscle cells. However, the mechanisms by which nonmuscle myosin II (NM-II) is recruited to those structures and assembled into functional bipolar filaments have remained elusive. We report that UNC-45a is a dynamic component of actin stress fibers and functions as a myosin chaperone in vivo. UNC-45a knockout cells display severe defects in stress fiber assembly and consequent abnormalities in cell morphogenesis, polarity, and migration. Experiments combining structured-illumination microscopy, gradient centrifugation, and proteasome inhibition approaches revealed that a large fraction of NM-II and myosin-1c molecules fail to fold in the absence of UNC-45a. The remaining properly folded NM-II molecules display defects in forming functional bipolar filaments. The C-terminal UNC-45/Cro1/She4p domain of UNC-45a is critical for NM-II folding, whereas the N-terminal tetratricopeptide repeat domain contributes to the assembly of functional stress fibers. Thus, UNC-45a promotes generation of contractile actomyosin bundles through synchronized NM-II folding and filament-assembly activities.
Collapse
Affiliation(s)
| | - Aidan M Fenix
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN
| | - Tommi M Kotila
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Giuseppe Balistreri
- Department of Biosciences, Division of General Microbiology, University of Helsinki, Helsinki, Finland
| | - Lassi Paavolainen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Dylan T Burnette
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN
| | - Pekka Lappalainen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| |
Collapse
|
39
|
Bookwalter CS, Tay CL, McCrorie R, Previs MJ, Lu H, Krementsova EB, Fagnant PM, Baum J, Trybus KM. Reconstitution of the core of the malaria parasite glideosome with recombinant Plasmodium class XIV myosin A and Plasmodium actin. J Biol Chem 2017; 292:19290-19303. [PMID: 28978649 PMCID: PMC5702669 DOI: 10.1074/jbc.m117.813972] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 09/27/2017] [Indexed: 11/08/2022] Open
Abstract
Motility of the apicomplexan malaria parasite Plasmodium falciparum is enabled by a multiprotein glideosome complex, whose core is the class XIV myosin motor, PfMyoA, and a divergent Plasmodium actin (PfAct1). Parasite motility is necessary for host-cell invasion and virulence, but studying its molecular basis has been hampered by unavailability of sufficient amounts of PfMyoA. Here, we expressed milligram quantities of functional full-length PfMyoA with the baculovirus/Sf9 cell expression system, which required a UCS (UNC-45/CRO1/She4p) family myosin chaperone from Plasmodium spp. In addition to the known light chain myosin tail interacting protein (MTIP), we identified an essential light chain (PfELC) that co-purified with PfMyoA isolated from parasite lysates. The speed at which PfMyoA moved actin was fastest with both light chains bound, consistent with the light chain–binding domain acting as a lever arm to amplify nucleotide-dependent motions in the motor domain. Surprisingly, PfELC binding to the heavy chain required that MTIP also be bound to the heavy chain, unlike MTIP that bound the heavy chain independently of PfELC. Neither the presence of calcium nor deletion of the MTIP N-terminal extension changed the speed of actin movement. Of note, PfMyoA moved filaments formed from Sf9 cell–expressed PfAct1 at the same speed as skeletal muscle actin. Duty ratio estimates suggested that as few as nine motors can power actin movement at maximal speed, a feature that may be necessitated by the dynamic nature of Plasmodium actin filaments in the parasite. In summary, we have reconstituted the essential core of the glideosome, enabling drug targeting of both of its core components to inhibit parasite invasion.
Collapse
Affiliation(s)
- Carol S Bookwalter
- From the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405 and
| | - Chwen L Tay
- the Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Rama McCrorie
- the Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Michael J Previs
- From the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405 and
| | - Hailong Lu
- From the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405 and
| | - Elena B Krementsova
- From the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405 and
| | - Patricia M Fagnant
- From the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405 and
| | - Jake Baum
- the Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Kathleen M Trybus
- From the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405 and
| |
Collapse
|
40
|
Fission yeast myosin Myo2 is down-regulated in actin affinity by light chain phosphorylation. Proc Natl Acad Sci U S A 2017; 114:E7236-E7244. [PMID: 28808035 DOI: 10.1073/pnas.1703161114] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Studies in fission yeast Schizosaccharomyces pombe have provided the basis for the most advanced models of the dynamics of the cytokinetic contractile ring. Myo2, a class-II myosin, is the major source of tension in the contractile ring, but how Myo2 is anchored and regulated to produce force is poorly understood. To enable more detailed biochemical/biophysical studies, Myo2 was expressed in the baculovirus/Sf9 insect cell system with its two native light chains, Rlc1 and Cdc4. Milligram yields of soluble, unphosphorylated Myo2 were obtained that exhibited high actin-activated ATPase activity and in vitro actin filament motility. The fission yeast specific chaperone Rng3 was thus not required for expression or activity. In contrast to nonmuscle myosins from animal cells that require phosphorylation of the regulatory light chain for activation, phosphorylation of Rlc1 markedly reduced the affinity of Myo2 for actin. Another unusual feature of Myo2 was that, unlike class-II myosins, which generally form bipolar filamentous structures, Myo2 showed no inclination to self-assemble at approximately physiological salt concentrations, as analyzed by sedimentation velocity ultracentrifugation. This lack of assembly supports the hypothesis that clusters of Myo2 depend on interactions at the cell cortex in structural units called nodes for force production during cytokinesis.
Collapse
|
41
|
Sochacki KA, Dickey AM, Strub MP, Taraska JW. Endocytic proteins are partitioned at the edge of the clathrin lattice in mammalian cells. Nat Cell Biol 2017; 19:352-361. [PMID: 28346440 DOI: 10.1038/ncb3498] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 02/23/2017] [Indexed: 12/15/2022]
Abstract
Dozens of proteins capture, polymerize and reshape the clathrin lattice during clathrin-mediated endocytosis (CME). How or if this ensemble of proteins is organized in relation to the clathrin coat is unknown. Here, we map key molecules involved in CME at the nanoscale using correlative super-resolution light and transmission electron microscopy. We localize 19 different endocytic proteins (amphiphysin1, AP2, β2-arrestin, CALM, clathrin, DAB2, dynamin2, EPS15, epsin1, epsin2, FCHO2, HIP1R, intersectin, NECAP, SNX9, stonin2, syndapin2, transferrin receptor, VAMP2) on thousands of individual clathrin structures, generating a comprehensive molecular architecture of endocytosis with nanoscale precision. We discover that endocytic proteins distribute into distinct spatial zones in relation to the edge of the clathrin lattice. The presence or concentrations of proteins within these zones vary at distinct stages of organelle development. We propose that endocytosis is driven by the recruitment, reorganization and loss of proteins within these partitioned nanoscale zones.
Collapse
Affiliation(s)
- Kem A Sochacki
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Andrea M Dickey
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Marie-Paule Strub
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Justin W Taraska
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| |
Collapse
|
42
|
Graf IR, Frey E. Generic Transport Mechanisms for Molecular Traffic in Cellular Protrusions. PHYSICAL REVIEW LETTERS 2017; 118:128101. [PMID: 28388182 DOI: 10.1103/physrevlett.118.128101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Indexed: 06/07/2023]
Abstract
Transport of molecular motors along protein filaments in a half-closed geometry is a common feature of biologically relevant processes in cellular protrusions. Using a lattice-gas model we study how the interplay between active and diffusive transport and mass conservation leads to localized domain walls and tip localization of the motors. We identify a mechanism for task sharing between the active motors (maintaining a gradient) and the diffusive motion (transport to the tip), which ensures that energy consumption is low and motor exchange mostly happens at the tip. These features are attributed to strong nearest-neighbor correlations that lead to a strong reduction of active currents, which we calculate analytically using an exact moment identity, and might prove useful for the understanding of correlations and active transport also in more elaborate systems.
Collapse
Affiliation(s)
- Isabella R Graf
- Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, D-80333 Munich, Germany
| | - Erwin Frey
- Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, D-80333 Munich, Germany
| |
Collapse
|
43
|
Myosin B of Plasmodium falciparum (PfMyoB): in silico prediction of its three-dimensional structure and its possible interaction with MTIP. Parasitol Res 2017; 116:1373-1382. [PMID: 28265752 DOI: 10.1007/s00436-017-5417-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 02/21/2017] [Indexed: 10/24/2022]
Abstract
The mobility and invasion strategy of Plasmodium falciparum is governed by a protein complex known as the glideosome, which contains an actin-myosin motor. It has been shown that myosin A of the parasite (PfMyoA) is the myosin of the glideosome, and the interaction of PfMyoA with myosin tail domain interacting protein (MTIP) determines its correct location and its ability to function in the complex. Because PfMyoA and myosin B of P. falciparum (PfMyoB) share high sequence identity, are both small proteins without a tail domain, belong to the class XIV myosins, and are expressed in late schizonts and merozoites, we suspect that these myosins may have similar or redundant functions. Therefore, this work examined the structural similarity between PfMyoA and PfMyoB and performed a molecular docking between PfMyoB and MTIP. Three-dimensional (3D) models obtained for PfMyoA and PfMyoB achieved high scores in the structural validation programs used, and their superimposition revealed high structural similarity, supporting the hypothesis of possible similar functions for these two proteins. The 3D interaction models obtained and energy values found suggested that interaction between PfMyoB and MTIP is possible. Given the apparent abundance of PfMyoA relative to PfMyoB in the parasite, we believe that the interaction between PfMyoB and MTIP would only be detectable in specific cellular environments because under normal circumstances, it would be masked by the interaction between PfMyoA and MTIP.
Collapse
|
44
|
Pinkoviezky I, Gov NS. Exclusion and Hierarchy of Time Scales Lead to Spatial Segregation of Molecular Motors in Cellular Protrusions. PHYSICAL REVIEW LETTERS 2017; 118:018102. [PMID: 28106430 DOI: 10.1103/physrevlett.118.018102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Indexed: 06/06/2023]
Abstract
Molecular motors that carry cargo along biopolymer filaments within cells play a crucial role in the functioning of the cell. In particular, these motors are essential for the formation and maintenance of the cellular protrusions that play key roles in motility and specific functionalities, such as the stereocilia in hair cells. Typically, there are several species of motors, carrying different cargos, that share the same track. Furthermore, it was observed that in the mature stereocilia, the different motors occupy well-segregated bands as a function of distance from the tip. We use a totally asymmetric exclusion process model with two- and three-motor species, to study the conditions that give rise to such spatial patterns. We find that the well-segregated bands appear for motors with a strong hierarchy of attachment or detachment rates. This is a striking example of pattern formation in nonequilibrium, low-dimensional systems.
Collapse
Affiliation(s)
- I Pinkoviezky
- Department of Chemical Physics, Weizmann Institute of Science, P.O. Box 26, Rehovot 76100, Israel
| | - N S Gov
- Department of Chemical Physics, Weizmann Institute of Science, P.O. Box 26, Rehovot 76100, Israel
| |
Collapse
|
45
|
Masters TA, Kendrick-Jones J, Buss F. Myosins: Domain Organisation, Motor Properties, Physiological Roles and Cellular Functions. Handb Exp Pharmacol 2017; 235:77-122. [PMID: 27757761 DOI: 10.1007/164_2016_29] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Myosins are cytoskeletal motor proteins that use energy derived from ATP hydrolysis to generate force and movement along actin filaments. Humans express 38 myosin genes belonging to 12 classes that participate in a diverse range of crucial activities, including muscle contraction, intracellular trafficking, cell division, motility, actin cytoskeletal organisation and cell signalling. Myosin malfunction has been implicated a variety of disorders including deafness, hypertrophic cardiomyopathy, Usher syndrome, Griscelli syndrome and cancer. In this chapter, we will first discuss the key structural and kinetic features that are conserved across the myosin family. Thereafter, we summarise for each member in turn its unique functional and structural adaptations, cellular roles and associated pathologies. Finally, we address the broad therapeutic potential for pharmacological interventions that target myosin family members.
Collapse
Affiliation(s)
- Thomas A Masters
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.
| | | | - Folma Buss
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| |
Collapse
|
46
|
Weck ML, Grega-Larson NE, Tyska MJ. MyTH4-FERM myosins in the assembly and maintenance of actin-based protrusions. Curr Opin Cell Biol 2016; 44:68-78. [PMID: 27836411 DOI: 10.1016/j.ceb.2016.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 10/12/2016] [Indexed: 12/13/2022]
Abstract
Unconventional myosins are actin-based molecular motors that serve a multitude of roles within the cell. One group of myosin motors, the MyTH4-FERM myosins, play an integral part in building and maintaining finger-like protrusions, which allow cells to interact with their external environment. Suggested to act primarily as transporters, these motor proteins enrich adhesion molecules, actin-regulatory proteins and other factors at the tips of filopodia, microvilli, and stereocilia. Below we review data from biophysical, biochemical, and cell biological studies, which implicate these myosins as central players in the assembly, maintenance and function of actin-based protrusions.
Collapse
Affiliation(s)
- Meredith L Weck
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, 3154 MRB III, PMB 407935, 465 21st Avenue South, Nashville, TN 37240-7935, United States
| | - Nathan E Grega-Larson
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, 3154 MRB III, PMB 407935, 465 21st Avenue South, Nashville, TN 37240-7935, United States
| | - Matthew J Tyska
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, 3154 MRB III, PMB 407935, 465 21st Avenue South, Nashville, TN 37240-7935, United States.
| |
Collapse
|
47
|
Rehman AU, Bird JE, Faridi R, Shahzad M, Shah S, Lee K, Khan SN, Imtiaz A, Ahmed ZM, Riazuddin S, Santos-Cortez RLP, Ahmad W, Leal SM, Riazuddin S, Friedman TB. Mutational Spectrum of MYO15A and the Molecular Mechanisms of DFNB3 Human Deafness. Hum Mutat 2016; 37:991-1003. [PMID: 27375115 DOI: 10.1002/humu.23042] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/26/2016] [Indexed: 12/17/2022]
Abstract
Deafness in humans is a common neurosensory disorder and is genetically heterogeneous. Across diverse ethnic groups, mutations of MYO15A at the DFNB3 locus appear to be the third or fourth most common cause of autosomal-recessive, nonsyndromic deafness. In 49 of the 67 exons of MYO15A, there are currently 192 recessive mutations identified, including 14 novel mutations reported here. These mutations are distributed uniformly across MYO15A with one enigmatic exception; the alternatively spliced giant exon 2, encoding 1,233 residues, has 17 truncating mutations but no convincing deafness-causing missense mutations. MYO15A encodes three distinct isoform classes, one of which is 395 kDa (3,530 residues), the largest member of the myosin superfamily of molecular motors. Studies of Myo15 mouse models that recapitulate DFNB3 revealed two different pathogenic mechanisms of hearing loss. In the inner ear, myosin 15 is necessary both for the development and the long-term maintenance of stereocilia, mechanosensory sound-transducing organelles that extend from the apical surface of hair cells. The goal of this Mutation Update is to provide a comprehensive review of mutations and functions of MYO15A.
Collapse
Affiliation(s)
- Atteeq U Rehman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, 20892
| | - Jonathan E Bird
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, 20892
| | - Rabia Faridi
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, 20892.,Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 54550, Pakistan
| | - Mohsin Shahzad
- Department of Otorhinolaryngology Head & Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, 21201
| | - Sujay Shah
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, 20892
| | - Kwanghyuk Lee
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Shaheen N Khan
- Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 54550, Pakistan
| | - Ayesha Imtiaz
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, 20892
| | - Zubair M Ahmed
- Department of Otorhinolaryngology Head & Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, 21201
| | - Saima Riazuddin
- Department of Otorhinolaryngology Head & Neck Surgery, School of Medicine, University of Maryland, Baltimore, Maryland, 21201
| | - Regie Lyn P Santos-Cortez
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Suzanne M Leal
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Sheikh Riazuddin
- Allama Iqbal Medical Research Centre, Jinnah Hospital Complex, University of Health Sciences, Lahore, 54550, Pakistan
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, 20892.
| |
Collapse
|
48
|
Abstract
The myosin holoenzyme is a multimeric protein complex consisting of heavy chains and light chains. Myosin light chains are calmodulin family members which are crucially involved in the mechanoenzymatic function of the myosin holoenzyme. This review examines the diversity of light chains within the myosin superfamily, discusses interactions between the light chain and the myosin heavy chain as well as regulatory and structural functions of the light chain as a subunit of the myosin holoenzyme. It covers aspects of the myosin light chain in the localization of the myosin holoenzyme, protein-protein interactions and light chain binding to non-myosin binding partners. Finally, this review challenges the dogma that myosin regulatory and essential light chain exclusively associate with conventional myosin heavy chains while unconventional myosin heavy chains usually associate with calmodulin.
Collapse
Affiliation(s)
- Sarah M Heissler
- a Laboratory of Molecular Physiology; National Heart, Lung, and Blood Institute; National Institutes of Health ; Bethesda , MD USA
| | - James R Sellers
- a Laboratory of Molecular Physiology; National Heart, Lung, and Blood Institute; National Institutes of Health ; Bethesda , MD USA
| |
Collapse
|
49
|
Heissler SM, Sellers JR. Four things to know about myosin light chains as reporters for non-muscle myosin-2 dynamics in live cells. Cytoskeleton (Hoboken) 2016; 72:65-70. [PMID: 25712372 DOI: 10.1002/cm.21212] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/19/2014] [Accepted: 02/03/2015] [Indexed: 11/07/2022]
Abstract
The interplay between non-muscle myosins-2 and filamentous actin results in cytoplasmic contractility which is essential for eukaryotic life. Concomitantly, there is tremendous interest in elucidating the physiological function and temporal localization of non-muscle myosin-2 in cells. A commonly used method to study the function and localization of non-muscle myosin-2 is to overexpress a fluorescent protein (FP)-tagged version of the regulatory light chain (RLC) which binds to the myosin-2 heavy chain by mass action. Caveats about this approach include findings from recent studies indicating that the RLC does not bind exclusively to the non-muscle myosin-2 heavy chain. Rather, it can also associate with the myosin heavy chains of several other classes as well as other targets than myosin. In addition, the presence of the FP moiety may compromise myosin's enzymatic and mechanical performance. This and other factors to be discussed in this commentary raise questions about the possible complications in using FP-RLC as a marker for the dynamic localization and regulatory aspects of non-muscle myosin-2 motor functions in cell biological experiments.
Collapse
Affiliation(s)
- Sarah M Heissler
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | | |
Collapse
|
50
|
Kondo T, Okada M, Kunihiro K, Takahashi M, Yaoita Y, Hosoya H, Hamao K. Characterization of myosin II regulatory light chain isoforms in HeLa cells. Cytoskeleton (Hoboken) 2016; 72:609-20. [DOI: 10.1002/cm.21268] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 11/27/2015] [Accepted: 12/07/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Tomo Kondo
- Department of Biological Science; Graduate School of Science, Hiroshima University; Higashihiroshima 739-8526 Japan
| | - Morihiro Okada
- Division of Embryology and Genetics; Institute for Amphibian Biology, Graduate School of Science, Hiroshima University; Higashihiroshima 739-8526 Japan
| | - Kayo Kunihiro
- Department of Biological Science; Graduate School of Science, Hiroshima University; Higashihiroshima 739-8526 Japan
| | - Masayuki Takahashi
- Department of Chemistry; Faculty of Science, Hokkaido University; Sapporo 010-0810 Japan
| | - Yoshio Yaoita
- Division of Embryology and Genetics; Institute for Amphibian Biology, Graduate School of Science, Hiroshima University; Higashihiroshima 739-8526 Japan
| | - Hiroshi Hosoya
- Department of Biological Science; Graduate School of Science, Hiroshima University; Higashihiroshima 739-8526 Japan
| | - Kozue Hamao
- Department of Biological Science; Graduate School of Science, Hiroshima University; Higashihiroshima 739-8526 Japan
| |
Collapse
|