1
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Gunther LK, Cirilo JA, Desetty R, Yengo CM. Deafness mutation in the MYO3A motor domain impairs actin protrusion elongation mechanism. Mol Biol Cell 2021; 33:ar5. [PMID: 34788109 PMCID: PMC8886822 DOI: 10.1091/mbc.e21-05-0232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Class III myosins are actin-based motors proposed to transport cargo to the distal tips of stereocilia in the inner ear hair cells and/or to participate in stereocilia length regulation, which is especially important during development. Mutations in the MYO3A gene are associated with delayed onset deafness. A previous study demonstrated that L697W, a dominant deafness mutation, disrupts MYO3A ATPase and motor properties but does not impair its ability to localize to the tips of actin protrusions. In the current study, we characterized the transient kinetic mechanism of the L697W motor ATPase cycle. Our kinetic analysis demonstrates that the mutation slows the ADP release and ATP hydrolysis steps, which results in a slight reduction in the duty ratio and slows detachment kinetics. Fluorescence recovery after photobleaching (FRAP) of filopodia tip localized L697W and WT MYO3A in COS-7 cells revealed that the mutant does not alter turnover or average intensity at the actin protrusion tips. We demonstrate that the mutation slows filopodia extension velocity in COS-7 cells which correlates with its twofold slower in vitro actin gliding velocity. Overall, this work allowed us to propose a model for how the motor properties of MYO3A are crucial for facilitating actin protrusion length regulation.
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Affiliation(s)
- Laura K Gunther
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, 17033
| | - Joseph A Cirilo
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, 17033
| | - Rohini Desetty
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, 17033
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, 17033
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2
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Characterization of a novel MYO3A missense mutation associated with a dominant form of late onset hearing loss. Sci Rep 2018; 8:8706. [PMID: 29880844 PMCID: PMC5992146 DOI: 10.1038/s41598-018-26818-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 05/18/2018] [Indexed: 01/08/2023] Open
Abstract
Whole-exome sequencing of samples from affected members of two unrelated families with late-onset non-syndromic hearing loss revealed a novel mutation (c.2090 T > G; NM_017433) in MYO3A. The mutation was confirmed in 36 affected individuals, showing autosomal dominant inheritance. The mutation alters a single residue (L697W or p.Leu697Trp) in the motor domain of the stereocilia protein MYO3A, leading to a reduction in ATPase activity, motility, and an increase in actin affinity. MYO3A-L697W showed reduced filopodial actin protrusion initiation in COS7 cells, and a predominant tipward accumulation at filopodia and stereocilia when coexpressed with wild-type MYO3A and espin-1, an actin-regulatory MYO3A cargo. The combined higher actin affinity and duty ratio of the mutant myosin cause increased retention time at stereocilia tips, resulting in the displacement of the wild-type MYO3A protein, which may impact cargo transport, stereocilia length, and mechanotransduction. The dominant negative effect of the altered myosin function explains the dominant inheritance of deafness.
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3
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Raval MH, Quintero OA, Weck ML, Unrath WC, Gallagher JW, Cui R, Kachar B, Tyska MJ, Yengo CM. Impact of the Motor and Tail Domains of Class III Myosins on Regulating the Formation and Elongation of Actin Protrusions. J Biol Chem 2016; 291:22781-22792. [PMID: 27582493 PMCID: PMC5077211 DOI: 10.1074/jbc.m116.733741] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 08/29/2016] [Indexed: 11/06/2022] Open
Abstract
Class III myosins (MYO3A and MYO3B) are proposed to function as transporters as well as length and ultrastructure regulators within stable actin-based protrusions such as stereocilia and calycal processes. MYO3A differs from MYO3B in that it contains an extended tail domain with an additional actin-binding motif. We examined how the properties of the motor and tail domains of human class III myosins impact their ability to enhance the formation and elongation of actin protrusions. Direct examination of the motor and enzymatic properties of human MYO3A and MYO3B revealed that MYO3A is a 2-fold faster motor with enhanced ATPase activity and actin affinity. A chimera in which the MYO3A tail was fused to the MYO3B motor demonstrated that motor activity correlates with formation and elongation of actin protrusions. We demonstrate that removal of individual exons (30-34) in the MYO3A tail does not prevent filopodia tip localization but abolishes the ability to enhance actin protrusion formation and elongation in COS7 cells. Interestingly, our results demonstrate that MYO3A slows filopodia dynamics and enhances filopodia lifetime in COS7 cells. We also demonstrate that MYO3A is more efficient than MYO3B at increasing formation and elongation of stable microvilli on the surface of cultured epithelial cells. We propose that the unique features of MYO3A, enhanced motor activity, and an extended tail with tail actin-binding motif, allow it to play an important role in stable actin protrusion length and ultrastructure maintenance.
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Affiliation(s)
- Manmeet H Raval
- From the Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania 17033
| | - Omar A Quintero
- the Department of Biology, University of Richmond, Richmond, Virginia 23173
| | - Meredith L Weck
- the Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - William C Unrath
- From the Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania 17033
| | - James W Gallagher
- the Department of Biology, Lincoln University, Philadelphia, Pennsylvania 19104, and
| | - Runjia Cui
- the Laboratory of Cell Structure and Dynamics, NIDCD, National Institutes of Health, Bethesda, Maryland 20892
| | - Bechara Kachar
- the Laboratory of Cell Structure and Dynamics, NIDCD, National Institutes of Health, Bethesda, Maryland 20892
| | - Matthew J Tyska
- the Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Christopher M Yengo
- From the Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania 17033,
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4
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Baum P, Vogt MA, Gass P, Unsicker K, von Bohlen und Halbach O. FGF-2 deficiency causes dysregulation of Arhgef6 and downstream targets in the cerebral cortex accompanied by altered neurite outgrowth and dendritic spine morphology. Int J Dev Neurosci 2016; 50:55-64. [PMID: 26970009 DOI: 10.1016/j.ijdevneu.2016.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 03/01/2016] [Accepted: 03/01/2016] [Indexed: 01/13/2023] Open
Abstract
Fibroblast growth factor 2 (FGF-2) is an abundant growth factor in the brain and exerts multiple functions on neural cells ranging from cell division, cell fate determination to differentiation. However, many details of the molecular mechanisms underlying the diverse functions of FGF-2 are poorly understood. In a comparative microarray analysis of motor sensory cortex (MSC) tissue of adult knockout (FGF-2(-/-)) and control (FGF-2(+/+)) mice, we found a substantial number of regulated genes, which are implicated in cytoskeletal machinery dynamics. Specifically, we found a prominent downregulation of Arhgef6. Arhgef6 mRNA was significantly reduced in the FGF-2(-/-) cortex, and Arhgef6 protein virtually absent, while RhoA protein levels were massively increased and Cdc42 protein levels were reduced. Since Arhgef6 is localized to dendritic spines, we next analyzed dendritic spines of adult FGF2(-/-) and control mouse cortices. Spine densities were significantly increased, whereas mean length of spines on dendrites of layer V of MSC neurons in adult FGF-2(-/-) mice was significantly decreased as compared to respective controls. Furthermore, neurite length in dissociated cortical cultures from E18 FGF-2(-/-) mice was significantly reduced at DIV7 as compared to wildtype neurons. Despite the fact that altered neuronal morphology and alterations in dendritic spines were observed, FGF-2(-/-) mice behave relatively unsuspicious in several behavioral tasks. However, FGF-2(-/-) mice exhibited decreased thermal pain sensitivity in the hotplate-test.
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Affiliation(s)
- Philip Baum
- Institut für Anatomie und Zellbiologie, Universitätsmedizin Greifswald, Germany; Anatomy & Cell Biology, Department of Molecular Embryology, University of Freiburg, Germany
| | - Miriam A Vogt
- AG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim/University of Heidelberg, Germany; RG Molecular Physiology of Hearing, Head and Neck Surgery Tübingen Hearing, Research Center (THRC),Department of Otolaryngology, University Hospital Tübingen, Germany
| | - Peter Gass
- AG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim/University of Heidelberg, Germany
| | - Klaus Unsicker
- Anatomy & Cell Biology, Department of Molecular Embryology, University of Freiburg, Germany
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5
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Ebrahim S, Avenarius MR, Grati M, Krey JF, Windsor AM, Sousa AD, Ballesteros A, Cui R, Millis BA, Salles FT, Baird MA, Davidson MW, Jones SM, Choi D, Dong L, Raval MH, Yengo CM, Barr-Gillespie PG, Kachar B. Stereocilia-staircase spacing is influenced by myosin III motors and their cargos espin-1 and espin-like. Nat Commun 2016; 7:10833. [PMID: 26926603 PMCID: PMC4773517 DOI: 10.1038/ncomms10833] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 01/25/2016] [Indexed: 12/12/2022] Open
Abstract
Hair cells tightly control the dimensions of their stereocilia, which are actin-rich protrusions with graded heights that mediate mechanotransduction in the inner ear. Two members of the myosin-III family, MYO3A and MYO3B, are thought to regulate stereocilia length by transporting cargos that control actin polymerization at stereocilia tips. We show that eliminating espin-1 (ESPN-1), an isoform of ESPN and a myosin-III cargo, dramatically alters the slope of the stereocilia staircase in a subset of hair cells. Furthermore, we show that espin-like (ESPNL), primarily present in developing stereocilia, is also a myosin-III cargo and is essential for normal hearing. ESPN-1 and ESPNL each bind MYO3A and MYO3B, but differentially influence how the two motors function. Consequently, functional properties of different motor-cargo combinations differentially affect molecular transport and the length of actin protrusions. This mechanism is used by hair cells to establish the required range of stereocilia lengths within a single cell.
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Affiliation(s)
- Seham Ebrahim
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Matthew R Avenarius
- Oregon Hearing Research Center and Vollum Institute, Oregon Health &Science University, Portland, Oregon 97239, USA
| | - M'hamed Grati
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jocelyn F Krey
- Oregon Hearing Research Center and Vollum Institute, Oregon Health &Science University, Portland, Oregon 97239, USA
| | - Alanna M Windsor
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Aurea D Sousa
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Angela Ballesteros
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Runjia Cui
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Bryan A Millis
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Felipe T Salles
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Michelle A Baird
- National High Magnetic Field Laboratory and Department of Biological Science, Florida State University, Tallahassee, Florida 32310, USA
| | - Michael W Davidson
- National High Magnetic Field Laboratory and Department of Biological Science, Florida State University, Tallahassee, Florida 32310, USA
| | - Sherri M Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, Nebraska 68583, USA
| | - Dongseok Choi
- Department of Public Health and Preventive Medicine, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Manmeet H Raval
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA
| | - Peter G Barr-Gillespie
- Oregon Hearing Research Center and Vollum Institute, Oregon Health &Science University, Portland, Oregon 97239, USA
| | - Bechara Kachar
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
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6
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Grati M, Yan D, Raval MH, Walsh T, Ma Q, Chakchouk I, Kannan-Sundhari A, Mittal R, Masmoudi S, Blanton SH, Tekin M, King MC, Yengo CM, Liu XZ. MYO3A Causes Human Dominant Deafness and Interacts with Protocadherin 15-CD2 Isoform. Hum Mutat 2016; 37:481-7. [PMID: 26841241 DOI: 10.1002/humu.22961] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/15/2016] [Indexed: 01/10/2023]
Abstract
Hereditary hearing loss (HL) is characterized by both allelic and locus genetic heterogeneity. Both recessive and dominant forms of HL may be caused by different mutations in the same deafness gene. In a family with post-lingual progressive non-syndromic deafness, whole-exome sequencing of genomic DNA from five hearing-impaired relatives revealed a single variant, p.Gly488Glu (rs145970949:G>A) in MYO3A, co-segregating with HL as an autosomal dominant trait. This amino acid change, predicted to be pathogenic, alters a highly conserved residue in the motor domain of MYO3A. The mutation severely alters the ATPase activity and motility of the protein in vitro, and the mutant protein fails to accumulate in the filopodia tips in COS7 cells. However, the mutant MYO3A was able to reach the tips of organotypic inner ear culture hair cell stereocilia, raising the possibility of a local effect on positioning of the mechanoelectrical transduction (MET) complex at the stereocilia tips. To address this hypothesis, we investigated the interaction of MYO3A with the cytosolic tail of the integral tip-link protein protocadherin 15 (PCDH15), a core component of MET complex. Interestingly, we uncovered a novel interaction between MYO3A and PCDH15 shedding new light on the function of myosin IIIA at stereocilia tips.
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Affiliation(s)
- M'hamed Grati
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Manmeet H Raval
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Tom Walsh
- Departments of Medicine and Genome Sciences, University of Washington, Seattle, Washington
| | - Qi Ma
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Imen Chakchouk
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida.,Laboratoire Procédés de Criblage Moléculaire et Cellulaire, Centre de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisie
| | | | - Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Saber Masmoudi
- Laboratoire Procédés de Criblage Moléculaire et Cellulaire, Centre de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisie
| | - Susan H Blanton
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida.,Dr. John T. Macdonald Foundation, Department of Human Genetics, and John P. Hussman Institute for Human Genomics, University of Miami, Miami, Florida
| | - Mustafa Tekin
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida.,Dr. John T. Macdonald Foundation, Department of Human Genetics, and John P. Hussman Institute for Human Genomics, University of Miami, Miami, Florida
| | - Mary-Claire King
- Departments of Medicine and Genome Sciences, University of Washington, Seattle, Washington
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida.,Dr. John T. Macdonald Foundation, Department of Human Genetics, and John P. Hussman Institute for Human Genomics, University of Miami, Miami, Florida.,Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, Hunan, China
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7
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Liu H, Li J, Raval MH, Yao N, Deng X, Lu Q, Nie S, Feng W, Wan J, Yengo CM, Liu W, Zhang M. Myosin III-mediated cross-linking and stimulation of actin bundling activity of Espin. eLife 2016; 5. [PMID: 26785147 PMCID: PMC4758956 DOI: 10.7554/elife.12856] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/18/2016] [Indexed: 11/13/2022] Open
Abstract
Class III myosins (Myo3) and actin-bundling protein Espin play critical roles in regulating the development and maintenance of stereocilia in vertebrate hair cells, and their defects cause hereditary hearing impairments. Myo3 interacts with Espin1 through its tail homology I motif (THDI), however it is not clear how Myo3 specifically acts through Espin1 to regulate the actin bundle assembly and stabilization. Here we discover that Myo3 THDI contains a pair of repeat sequences capable of independently and strongly binding to the ankyrin repeats of Espin1, revealing an unexpected Myo3-mediated cross-linking mechanism of Espin1. The structures of Myo3 in complex with Espin1 not only elucidate the mechanism of the binding, but also reveal a Myo3-induced release of Espin1 auto-inhibition mechanism. We also provide evidence that Myo3-mediated cross-linking can further promote actin fiber bundling activity of Espin1.
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Affiliation(s)
- Haiyang Liu
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Jianchao Li
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Manmeet H Raval
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, United States
| | - Ningning Yao
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Xiaoying Deng
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Qing Lu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Si Nie
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Wei Feng
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jun Wan
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.,Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, United States
| | - Wei Liu
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.,Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Mingjie Zhang
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.,Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China.,Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Hong Kong, China
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8
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Lelli A, Michel V, Boutet de Monvel J, Cortese M, Bosch-Grau M, Aghaie A, Perfettini I, Dupont T, Avan P, El-Amraoui A, Petit C. Class III myosins shape the auditory hair bundles by limiting microvilli and stereocilia growth. J Cell Biol 2016; 212:231-44. [PMID: 26754646 PMCID: PMC4738386 DOI: 10.1083/jcb.201509017] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/07/2015] [Indexed: 11/22/2022] Open
Abstract
Analysis of mice deficient for myosin IIIa and myosin IIIb shows that class III myosins limit the elongation of stereocilia and of subsequently regressing microvilli, thus contributing to the early hair bundle shaping. The precise architecture of hair bundles, the arrays of mechanosensitive microvilli-like stereocilia crowning the auditory hair cells, is essential to hearing. Myosin IIIa, defective in the late-onset deafness form DFNB30, has been proposed to transport espin-1 to the tips of stereocilia, thereby promoting their elongation. We show that Myo3a−/−Myo3b−/− mice lacking myosin IIIa and myosin IIIb are profoundly deaf, whereas Myo3a-cKO Myo3b−/− mice lacking myosin IIIb and losing myosin IIIa postnatally have normal hearing. Myo3a−/−Myo3b−/− cochlear hair bundles display robust mechanoelectrical transduction currents with normal kinetics but show severe embryonic abnormalities whose features rapidly change. These include abnormally tall and numerous microvilli or stereocilia, ungraded stereocilia bundles, and bundle rounding and closure. Surprisingly, espin-1 is properly targeted to Myo3a−/−Myo3b−/− stereocilia tips. Our results uncover the critical role that class III myosins play redundantly in hair-bundle morphogenesis; they unexpectedly limit the elongation of stereocilia and of subsequently regressing microvilli, thus contributing to the early hair bundle shaping.
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Affiliation(s)
- Andrea Lelli
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France
| | - Vincent Michel
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France
| | - Jacques Boutet de Monvel
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France
| | - Matteo Cortese
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France
| | - Montserrat Bosch-Grau
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France
| | - Asadollah Aghaie
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France Syndrome de Usher et Autres Atteintes Rétino-Cochléaires, Institut de la Vision, 75012 Paris, France
| | - Isabelle Perfettini
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France
| | - Typhaine Dupont
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France
| | - Paul Avan
- Laboratoire de Biophysique Sensorielle, Faculté de Médecine, Université d'Auvergne; Biophysique Médicale, Centre Jean Perrin, 63000 Clermont-Ferrand, France
| | - Aziz El-Amraoui
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France
| | - Christine Petit
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75724 Paris, Cedex 15, France Unité Mixte de Recherche UMRS1120, Institut National de la Santé et de la Recherche Médicale, 75015 Paris, France Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris VI), Complexité du Vivant, 75005 Paris, France Syndrome de Usher et Autres Atteintes Rétino-Cochléaires, Institut de la Vision, 75012 Paris, France Collège de France, 75005 Paris, France
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9
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Yochelis A, Ebrahim S, Millis B, Cui R, Kachar B, Naoz M, Gov NS. Self-organization of waves and pulse trains by molecular motors in cellular protrusions. Sci Rep 2015; 5:13521. [PMID: 26335545 PMCID: PMC4558574 DOI: 10.1038/srep13521] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/29/2015] [Indexed: 11/13/2022] Open
Abstract
Actin-based cellular protrusions are an ubiquitous feature of cells, performing a variety of critical functions ranging from cell-cell communication to cell motility. The formation and maintenance of these protrusions relies on the transport of proteins via myosin motors, to the protrusion tip. While tip-directed motion leads to accumulation of motors (and their molecular cargo) at the protrusion tip, it is observed that motors also form rearward moving, periodic and isolated aggregates. The origins and mechanisms of these aggregates, and whether they are important for the recycling of motors, remain open puzzles. Motivated by novel myosin-XV experiments, a mass conserving reaction-diffusion-advection model is proposed. The model incorporates a non-linear cooperative interaction between motors, which converts them between an active and an inactive state. Specifically, the type of aggregate formed (traveling waves or pulse-trains) is linked to the kinetics of motors at the protrusion tip which is introduced by a boundary condition. These pattern selection mechanisms are found not only to qualitatively agree with empirical observations but open new vistas to the transport phenomena by molecular motors in general.
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Affiliation(s)
- A Yochelis
- Department of Solar Energy and Environmental Physics, Swiss Institute for Dryland Environmental and Energy Research, Blaustein Institutes for Desert Research (BIDR), Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion 84990, Israel
| | - S Ebrahim
- Laboratory of Cell Structure and Dynamics, NIDCD, National Institutes of Health, 50 South Drive, Bethesda, MD 20892-8027, USA
| | - B Millis
- Laboratory of Cell Structure and Dynamics, NIDCD, National Institutes of Health, 50 South Drive, Bethesda, MD 20892-8027, USA
| | - R Cui
- Laboratory of Cell Structure and Dynamics, NIDCD, National Institutes of Health, 50 South Drive, Bethesda, MD 20892-8027, USA
| | - B Kachar
- Laboratory of Cell Structure and Dynamics, NIDCD, National Institutes of Health, 50 South Drive, Bethesda, MD 20892-8027, USA
| | - M Naoz
- Department of Chemical Physics, Weizmann Institute of Science, P.O.B. 26, Rehovot, Israel 76100
| | - N S Gov
- Department of Chemical Physics, Weizmann Institute of Science, P.O.B. 26, Rehovot, Israel 76100
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Mecklenburg KL, Freed SA, Raval M, Quintero OA, Yengo CM, O'Tousa JE. Invertebrate and vertebrate class III myosins interact with MORN repeat-containing adaptor proteins. PLoS One 2015; 10:e0122502. [PMID: 25822849 PMCID: PMC4379085 DOI: 10.1371/journal.pone.0122502] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 02/18/2015] [Indexed: 12/22/2022] Open
Abstract
In Drosophila photoreceptors, the NINAC-encoded myosin III is found in a complex with a small, MORN-repeat containing, protein Retinophilin (RTP). Expression of these two proteins in other cell types showed NINAC myosin III behavior is altered by RTP. NINAC deletion constructs were used to map the RTP binding site within the proximal tail domain of NINAC. In vertebrates, the RTP ortholog is MORN4. Co-precipitation experiments demonstrated that human MORN4 binds to human myosin IIIA (MYO3A). In COS7 cells, MORN4 and MYO3A, but not MORN4 and MYO3B, co-localize to actin rich filopodia extensions. Deletion analysis mapped the MORN4 binding to the proximal region of the MYO3A tail domain. MYO3A dependent MORN4 tip localization suggests that MYO3A functions as a motor that transports MORN4 to the filopodia tips and MORN4 may enhance MYO3A tip localization by tethering it to the plasma membrane at the protrusion tips. These results establish conserved features of the RTP/MORN4 family: they bind within the tail domain of myosin IIIs to control their behavior.
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Affiliation(s)
- Kirk L. Mecklenburg
- Department of Biology, Indiana University South Bend, South Bend, Indiana, United States of America
| | - Stephanie A. Freed
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Manmeet Raval
- Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, United States of America
| | - Omar A. Quintero
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Christopher M. Yengo
- Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, United States of America
- * E-mail: (CY); (JO)
| | - Joseph. E. O'Tousa
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
- * E-mail: (CY); (JO)
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Pinkoviezky I, Gov NS. Traffic jams and shocks of molecular motors inside cellular protrusions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:052703. [PMID: 25353825 DOI: 10.1103/physreve.89.052703] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Indexed: 06/04/2023]
Abstract
Molecular motors are involved in key transport processes inside actin-based cellular protrusions. The motors carry cargo proteins to the protrusion tip which participate in regulating the actin polymerization and play a key role in facilitating the growth and formation of such protrusions. It is observed that the motors accumulate at the tips of cellular protrusions and form aggregates that are found to drift towards the protrusion base at the rate of actin treadmilling. We present a one-dimensional driven lattice model, where motors become inactive after delivering their cargo at the tip, or by loosing their cargo to a cargoless neighbor. The results suggest that the experimental observations may be explained by the formation of traffic jams that form at the tip. The model is solved using a novel application of mean-field and shock analysis. We find a new class of shocks that undergo intermittent collapses. Extensions with attachment and detachment events and relevance to experiments are briefly described.
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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
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Pinkoviezky I, Gov NS. Transport dynamics of molecular motors that switch between an active and inactive state. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:022714. [PMID: 24032871 DOI: 10.1103/physreve.88.022714] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/11/2013] [Indexed: 06/02/2023]
Abstract
Molecular motors are involved in key transport processes in the cell. Many of these motors can switch from an active to a nonactive state, either spontaneously or depending on their interaction with other molecules. When active, the motors move processively along the filaments, while when inactive they are stationary. We treat here the simple case of spontaneously switching motors, between the active and inactive states, along an open linear track. We use our recent analogy with vehicular traffic, where we go beyond the mean-field description. We map the phase diagram of this system, and find that it clearly breaks the symmetry between the different phases, as compared to the standard total asymmetric exclusion process. We make several predictions that may be testable using molecular motors in vitro and in living cells.
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Affiliation(s)
- I Pinkoviezky
- Department of Chemical Physics, Weizmann Institute of Science, P.O. Box 26, Rehovot, Israel 76100
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