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Morton GM, Toledo MP, Zheng Y, Zheng C, Megraw TL. A distinct isoform of Msp300/Nesprin organizes the perinuclear microtubule organizing center in adipose cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.601268. [PMID: 38979285 PMCID: PMC11230431 DOI: 10.1101/2024.06.28.601268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
In many cell types, disparate non-centrosomal microtubule-organizing centers (ncMTOCs) replace functional centrosomes and serve the unique needs of the cell types in which they are formed. In Drosophila fat body cells (adipocytes), an ncMTOC is organized on the nuclear surface. This perinuclear ncMTOC is anchored by Msp300, encoded by one of two Nesprin-encoding genes in Drosophila. Msp300 and the spectraplakin short stop (shot) are co-dependent for localization to the nuclear envelope to generate the ncMTOC where they recruit the microtubule minus-end stabilizer Patronin (CAMSAP). The fat body perinuclear ncMTOC requires Patronin, Ninein, and Msps (ortholog of ch-TOG), but does not require γ-tubulin for MT assembly. The Msp300 gene is complex, encoding at least eleven isoforms. Here we show that two Msp300 isoforms, Msp300-PE and -PG, are required and only one, Msp300-PE, appears sufficient for generation of the ncMTOC. Loss of Msp300-PE,-PG retains the presence of the other isoforms at the nuclear surface, indicating that they are not sufficient to generate the ncMTOC. Loss of Msp300-PE,-PG results in severe loss of localization of shot and Patronin, and disruption of the MT array. This results in nuclear mispositioning and loss of endosomal trafficking. Msp300-PE has an unusual domain structure including a lack of a KASH domain and very few spectrin repeats and appears therefore to have a highly derived function suited to generating an ncMTOC on the nuclear surface.
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Affiliation(s)
- Garret M Morton
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Maria Pilar Toledo
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Yiming Zheng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiang'an Hospital of Xiamen University, Xiamen University, Xiamen, China, 361102, and Shenzhen Research Institute of Xiamen University, Shenzhen, China, 518057
| | - Chunfeng Zheng
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Timothy L Megraw
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
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2
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Bougaran P, Bautch VL. Life at the crossroads: the nuclear LINC complex and vascular mechanotransduction. Front Physiol 2024; 15:1411995. [PMID: 38831796 PMCID: PMC11144885 DOI: 10.3389/fphys.2024.1411995] [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: 04/03/2024] [Accepted: 05/02/2024] [Indexed: 06/05/2024] Open
Abstract
Vascular endothelial cells line the inner surface of all blood vessels, where they are exposed to polarized mechanical forces throughout their lifespan. Both basal substrate interactions and apical blood flow-induced shear stress regulate blood vessel development, remodeling, and maintenance of vascular homeostasis. Disruption of these interactions leads to dysfunction and vascular pathologies, although how forces are sensed and integrated to affect endothelial cell behaviors is incompletely understood. Recently the endothelial cell nucleus has emerged as a prominent force-transducing organelle that participates in vascular mechanotransduction, via communication to and from cell-cell and cell-matrix junctions. The LINC complex, composed of SUN and nesprin proteins, spans the nuclear membranes and connects the nuclear lamina, the nuclear envelope, and the cytoskeleton. Here we review LINC complex involvement in endothelial cell mechanotransduction, describe unique and overlapping functions of each LINC complex component, and consider emerging evidence that two major SUN proteins, SUN1 and SUN2, orchestrate a complex interplay that extends outward to cell-cell and cell-matrix junctions and inward to interactions within the nucleus and chromatin. We discuss these findings in relation to vascular pathologies such as Hutchinson-Gilford progeria syndrome, a premature aging disorder with cardiovascular impairment. More knowledge of LINC complex regulation and function will help to understand how the nucleus participates in endothelial cell force sensing and how dysfunction leads to cardiovascular disease.
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Affiliation(s)
- Pauline Bougaran
- Department of Biology, The University of North Carolina, Chapel Hill, NC, United States
| | - Victoria L. Bautch
- Department of Biology, The University of North Carolina, Chapel Hill, NC, United States
- McAllister Heart Institute, The University of North Carolina, Chapel Hill, NC, United States
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3
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Gwilliam K, Sperber M, Perry K, Rose KP, Ginsberg L, Paladugu N, Song Y, Milon B, Elkon R, Hertzano R. A cell type-specific approach to elucidate the role of miR-96 in inner ear hair cells. FRONTIERS IN AUDIOLOGY AND OTOLOGY 2024; 2:1400576. [PMID: 38826689 PMCID: PMC11141775 DOI: 10.3389/fauot.2024.1400576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Introduction Mutations in microRNA-96 (miR-96), a microRNA expressed within the hair cells (HCs) of the inner ear, result in progressive hearing loss in both mouse models and humans. In this study, we present the first HC-specific RNA-sequencing (RNA-seq) dataset from newborn Mir96Dmdo heterozygous, homozygous mutant, and wildtype mice. Methods Bulk RNA-seq was performed on HCs of newborn Mir96Dmdo heterozygous, homozygous mutant, and wildtype mice. Differentially expressed gene analysis was conducted on Mir96Dmdo homozygous mutant HCs compared to wildtype littermate controls, followed by GO term and protein-protein interaction analysis on these differentially expressed genes. Results We identify 215 upregulated and 428 downregulated genes in the HCs of the Mir96Dmdo homozygous mutant mice compared to their wildtype littermate controls. Many of the significantly downregulated genes in Mir96Dmdo homozygous mutant HCs have established roles in HC development and/or known roles in deafness including Myo15a, Myo7a, Ush1c, Gfi1, and Ptprq and have enrichment in gene ontology (GO) terms with biological functions such as sensory perception of sound. Interestingly, upregulated genes in Mir96Dmdo homozygous mutants, including possible miR-96 direct targets, show higher wildtype expression in supporting cells compared to HCs. Conclusion Our data further support a role for miR-96 in HC development, possibly as a repressor of supporting cell transcriptional programs in HCs. The HC-specific Mir96Dmdo RNA-seq data set generated from this manuscript are now publicly available in a dedicated profile in the gene expression analysis resource (gEAR-https://umgear.org/p?l=miR96).
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Affiliation(s)
- Kathleen Gwilliam
- Section on Omics and Translational Science of Hearing, Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States
| | - Michal Sperber
- Department of Human Molecular Genetics and Biochemistry, Tel Aviv University School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Katherine Perry
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Kevin P. Rose
- Section on Omics and Translational Science of Hearing, Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States
| | - Laura Ginsberg
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Nikhil Paladugu
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Yang Song
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Beatrice Milon
- Section on Omics and Translational Science of Hearing, Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Tel Aviv University School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ronna Hertzano
- Section on Omics and Translational Science of Hearing, Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, United States
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States
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4
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Zi-Yi Z, Qin Q, Fei Z, Cun-Yu C, Lin T. Nesprin proteins: bridging nuclear envelope dynamics to muscular dysfunction. Cell Commun Signal 2024; 22:208. [PMID: 38566066 PMCID: PMC10986154 DOI: 10.1186/s12964-024-01593-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 03/24/2024] [Indexed: 04/04/2024] Open
Abstract
This review presents a comprehensive exploration of the pivotal role played by the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, with a particular focus on Nesprin proteins, in cellular mechanics and the pathogenesis of muscular diseases. Distinguishing itself from prior works, the analysis delves deeply into the intricate interplay of the LINC complex, emphasizing its indispensable contribution to maintaining cellular structural integrity, especially in mechanically sensitive tissues such as cardiac and striated muscles. Additionally, the significant association between mutations in Nesprin proteins and the onset of Dilated Cardiomyopathy (DCM) and Emery-Dreifuss Muscular Dystrophy (EDMD) is highlighted, underscoring their pivotal role in disease pathogenesis. Through a comprehensive examination of DCM and EDMD cases, the review elucidates the disruptions in the LINC complex, nuclear morphology alterations, and muscular developmental disorders, thus emphasizing the essential function of an intact LINC complex in preserving muscle physiological functions. Moreover, the review provides novel insights into the implications of Nesprin mutations for cellular dynamics in the pathogenesis of muscular diseases, particularly in maintaining cardiac structural and functional integrity. Furthermore, advanced therapeutic strategies, including rectifying Nesprin gene mutations, controlling Nesprin protein expression, enhancing LINC complex functionality, and augmenting cardiac muscle cell function are proposed. By shedding light on the intricate molecular mechanisms underlying nuclear-cytoskeletal interactions, the review lays the groundwork for future research and therapeutic interventions aimed at addressing genetic muscle disorders.
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Affiliation(s)
- Zhou Zi-Yi
- Department of Cardiology, Yichang Central People's Hospital, Yichang, 443003, Hubei, People's Republic of China
- School of Basic Medicine, China Three Gorges University, Yichang, 443000, Hubei, People's Republic of China
| | - Qin Qin
- Department of Cardiology, Yichang Central People's Hospital, Yichang, 443003, Hubei, People's Republic of China
- School of Basic Medicine, China Three Gorges University, Yichang, 443000, Hubei, People's Republic of China
| | - Zhou Fei
- Department of Cardiology, Yichang Central People's Hospital, Yichang, 443003, Hubei, People's Republic of China
| | - Cao Cun-Yu
- School of Basic Medicine, China Three Gorges University, Yichang, 443000, Hubei, People's Republic of China
- College of Basic Medical Sciences, Hubei Key Laboratory of Tumor Microencironment and immunotherapy, China Three Gorges University, Yichang, 443000, Hubei, People's Republic of China
| | - Teng Lin
- Department of Cardiology, Yichang Central People's Hospital, Yichang, 443003, Hubei, People's Republic of China.
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, SE5 9NU, UK.
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Gurusaran M, Erlandsen BS, Davies OR. The crystal structure of SUN1-KASH6 reveals an asymmetric LINC complex architecture compatible with nuclear membrane insertion. Commun Biol 2024; 7:138. [PMID: 38291267 PMCID: PMC10827754 DOI: 10.1038/s42003-024-05794-6] [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: 06/14/2023] [Accepted: 01/08/2024] [Indexed: 02/01/2024] Open
Abstract
The LINC complex transmits cytoskeletal forces into the nucleus to control the structure and movement of nuclear contents. It is formed of nuclear SUN and cytoplasmic KASH proteins, which interact within the nuclear lumen, immediately below the outer nuclear membrane. However, the symmetrical location of KASH molecules within SUN-KASH complexes in previous crystal structures has been difficult to reconcile with the steric requirements for insertion of their immediately upstream transmembrane helices into the outer nuclear membrane. Here, we report the crystal structure of the SUN-KASH complex between SUN1 and JAW1/LRMP (KASH6) in an asymmetric 9:6 configuration. This intertwined assembly involves two distinct KASH conformations such that all six KASH molecules emerge on the same molecular surface. Hence, they are ideally positioned for insertion of upstream sequences into the outer nuclear membrane. Thus, we report a SUN-KASH complex architecture that appears to be directly compatible with its biological role.
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Affiliation(s)
- Manickam Gurusaran
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Benedikte S Erlandsen
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Owen R Davies
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK.
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6
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Baskerville V, Rapuri S, Mehlhop E, Coyne AN. SUN1 facilitates CHMP7 nuclear influx and injury cascades in sporadic amyotrophic lateral sclerosis. Brain 2024; 147:109-121. [PMID: 37639327 PMCID: PMC10766250 DOI: 10.1093/brain/awad291] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/16/2023] [Accepted: 08/07/2023] [Indexed: 08/31/2023] Open
Abstract
We have recently identified the aberrant nuclear accumulation of the ESCRT-III protein CHMP7 as an initiating event that leads to a significant injury to the nuclear pore complex (NPC) characterized by the reduction of specific nucleoporins from the neuronal NPC in sporadic amyotrophic lateral sclerosis (sALS) and C9orf72 ALS/frontotemporal dementia (FTD)-induced pluripotent stem cell-derived neurons (iPSNs), a phenomenon also observed in post-mortem patient tissues. Importantly, this NPC injury is sufficient to contribute to TDP-43 dysfunction and mislocalization, a common pathological hallmark of neurodegenerative diseases. However, the molecular mechanisms and events that give rise to increased nuclear translocation and/or retention of CHMP7 to initiate this pathophysiological cascade remain largely unknown. Here, using an iPSN model of sALS, we demonstrate that impaired NPC permeability barrier integrity and interactions with the LINC complex protein SUN1 facilitate CHMP7 nuclear localization and the subsequent 'activation' of NPC injury cascades. Collectively, our data provide mechanistic insights in the pathophysiological underpinnings of ALS/FTD and highlight SUN1 as a potent contributor to and modifier of CHMP7-mediated toxicity in sALS pathogenesis.
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Affiliation(s)
- Victoria Baskerville
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Sampath Rapuri
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Emma Mehlhop
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alyssa N Coyne
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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7
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Gurusaran M, Biemans JJ, Wood CW, Davies OR. Molecular insights into LINC complex architecture through the crystal structure of a luminal trimeric coiled-coil domain of SUN1. Front Cell Dev Biol 2023; 11:1144277. [PMID: 37416798 PMCID: PMC10320395 DOI: 10.3389/fcell.2023.1144277] [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: 01/14/2023] [Accepted: 06/09/2023] [Indexed: 07/08/2023] Open
Abstract
The LINC complex, consisting of interacting SUN and KASH proteins, mechanically couples nuclear contents to the cytoskeleton. In meiosis, the LINC complex transmits microtubule-generated forces to chromosome ends, driving the rapid chromosome movements that are necessary for synapsis and crossing over. In somatic cells, it defines nuclear shape and positioning, and has a number of specialised roles, including hearing. Here, we report the X-ray crystal structure of a coiled-coiled domain of SUN1's luminal region, providing an architectural foundation for how SUN1 traverses the nuclear lumen, from the inner nuclear membrane to its interaction with KASH proteins at the outer nuclear membrane. In combination with light and X-ray scattering, molecular dynamics and structure-directed modelling, we present a model of SUN1's entire luminal region. This model highlights inherent flexibility between structured domains, and raises the possibility that domain-swap interactions may establish a LINC complex network for the coordinated transmission of cytoskeletal forces.
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Affiliation(s)
- Manickam Gurusaran
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Jelle J. Biemans
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Christopher W. Wood
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Owen R. Davies
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
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8
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Lewis MA, Schulte J, Matthews L, Vaden KI, Steves CJ, Williams FMK, Schulte BA, Dubno JR, Steel KP. Accurate phenotypic classification and exome sequencing allow identification of novel genes and variants associated with adult-onset hearing loss. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.04.27.23289040. [PMID: 37163093 PMCID: PMC10168485 DOI: 10.1101/2023.04.27.23289040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Adult-onset progressive hearing loss is a common, complex disease with a strong genetic component. Although to date over 150 genes have been identified as contributing to human hearing loss, many more remain to be discovered, as does most of the underlying genetic diversity. Many different variants have been found to underlie adult-onset hearing loss, but they tend to be rare variants with a high impact upon the gene product. It is likely that combinations of more common, lower impact variants also play a role in the prevalence of the disease. Here we present our exome study of hearing loss in a cohort of 532 older adult volunteers with extensive phenotypic data, including 99 older adults with normal hearing, an important control set. Firstly, we carried out an outlier analysis to identify genes with a high variant load in older adults with hearing loss compared to those with normal hearing. Secondly, we used audiometric threshold data to identify individual variants which appear to contribute to different threshold values. We followed up these analyses in a second cohort. Using these approaches, we identified genes and variants linked to better hearing as well as those linked to worse hearing. These analyses identified some known deafness genes, demonstrating proof of principle of our approach. However, most of the candidate genes are novel associations with hearing loss. While the results support the suggestion that genes responsible for severe deafness may also be involved in milder hearing loss, they also suggest that there are many more genes involved in hearing which remain to be identified. Our candidate gene lists may provide useful starting points for improved diagnosis and drug development.
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Affiliation(s)
- Morag A Lewis
- Wolfson Centre for Age-Related Diseases, King's College London, SE1 1UL, UK
- The Medical University of South Carolina, SC, USA
| | | | | | | | - Claire J Steves
- Department of Twin Research and Genetic Epidemiology, King's College London, School of Life Course and Population Sciences, London, UK
| | - Frances M K Williams
- Department of Twin Research and Genetic Epidemiology, King's College London, School of Life Course and Population Sciences, London, UK
| | | | - Judy R Dubno
- The Medical University of South Carolina, SC, USA
| | - Karen P Steel
- Wolfson Centre for Age-Related Diseases, King's College London, SE1 1UL, UK
- The Medical University of South Carolina, SC, USA
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Nuclear Translocation Triggered at the Onset of Hearing in Cochlear Inner Hair Cells of Rats and Mice. J Assoc Res Otolaryngol 2023:10.1007/s10162-023-00894-2. [PMID: 36932316 DOI: 10.1007/s10162-023-00894-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 02/21/2023] [Indexed: 03/19/2023] Open
Abstract
PURPOSE Nuclear position is precisely orchestrated during cell division, migration, and maturation of cells and tissues. Here we report a previously unrecognized, programmed movement of the nucleus in rat and mouse cochlear inner hair cells (IHCs) coinciding with the functional maturation of inner hair cells around the onset of hearing. METHODS We measured hair cell length and nuclear position from confocal scans of immunofluorescence-labeled hair cells from whole-mount cochlear preparations throughout post-natal development. RESULTS In early post-natal days, the IHC experiences a period of sustained growth, during which the nucleus sits at the very basal pole of the cell, far from the apically located mechano-transducing stereocilia, but close to where synapses with primary afferent and efferent neurons are forming. After IHCs reach their final length, the nucleus moves to occupy a new position half-way along the length of the cell. Nuclear translocation begins in the middle turn, completes throughout the cochlea within 2-3 days, and coincides with the emergence of endolymphatic potential, the acquisition of big-conductance potassium channels (BK), and the onset of acoustic hearing. IHCs cultured in-vitro without endolymphatic potential (EP) do not grow, do not express BK, and do not experience nuclear movement. IHCs cultured in high K+ solutions (to simulate EP) grow but do not experience nuclear movement or acquire BK channels. CONCLUSION Nuclear migration at the onset of hearing is a key step in the morphological maturation of IHCs. Whether this plays a role in functional maturation remains to be explored.
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10
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Taiber S, Gozlan O, Cohen R, Andrade LR, Gregory EF, Starr DA, Moran Y, Hipp R, Kelley MW, Manor U, Sprinzak D, Avraham KB. A Nesprin-4/kinesin-1 cargo model for nuclear positioning in cochlear outer hair cells. Front Cell Dev Biol 2022; 10:974168. [PMID: 36211453 PMCID: PMC9537699 DOI: 10.3389/fcell.2022.974168] [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: 06/20/2022] [Accepted: 09/07/2022] [Indexed: 11/14/2022] Open
Abstract
Nuclear positioning is important for the functionality of many cell types and is mediated by interactions of cytoskeletal elements and nucleoskeleton proteins. Nesprin proteins, part of the linker of nucleoskeleton and cytoskeleton (LINC) complex, have been shown to participate in nuclear positioning in multiple cell types. Outer hair cells (OHCs) in the inner ear are specialized sensory epithelial cells that utilize somatic electromotility to amplify auditory signals in the cochlea. Recently, Nesprin-4 (encoded by Syne4) was shown to play a crucial role in nuclear positioning in OHCs. Syne4 deficiency in humans and mice leads to mislocalization of the OHC nuclei and cell death resulting in deafness. However, it is unknown how Nesprin-4 mediates the position of the nucleus, and which other molecular components are involved in this process. Here, we show that the interaction of Nesprin-4 and the microtubule motor kinesin-1 is mediated by a conserved 4 amino-acid motif. Using in vivo AAV gene delivery, we show that this interaction is critical for nuclear positioning and hearing in mice. Nuclear mislocalization and cell death of OHCs coincide with the onset of hearing and electromotility and are solely restricted to outer, but not inner, hair cells. Likewise, the C. elegans functional homolog of Nesprin-4, UNC-83, uses a similar motif to mediate interactions between migrating nuclei and kinesin-1. Overall, our results suggest that OHCs require unique cellular machinery for proper nuclear positioning at the onset of electromotility. This machinery relies on the interaction between Nesprin-4 and kinesin-1 motors supporting a microtubule cargo model for nuclear positioning.
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Affiliation(s)
- Shahar Taiber
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel,School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Oren Gozlan
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Roie Cohen
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Leonardo R. Andrade
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Ellen F. Gregory
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States
| | - Daniel A. Starr
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States
| | - Yehu Moran
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rebecca Hipp
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - Matthew W. Kelley
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - Uri Manor
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
| | - David Sprinzak
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel,*Correspondence: David Sprinzak, ; Karen B. Avraham,
| | - Karen B. Avraham
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel,*Correspondence: David Sprinzak, ; Karen B. Avraham,
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11
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Searching for the Molecular Basis of Partial Deafness. Int J Mol Sci 2022; 23:ijms23116029. [PMID: 35682719 PMCID: PMC9181477 DOI: 10.3390/ijms23116029] [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: 03/31/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 02/04/2023] Open
Abstract
Hearing is an important human sense for communicating and connecting with others. Partial deafness (PD) is a common hearing problem, in which there is a down-sloping audiogram. In this study, we apply a practical system for classifying PD patients, used for treatment purposes, to distinguish two groups of patients: one with almost normal hearing thresholds at low frequencies (PDT-EC, n = 20), and a second group with poorer thresholds at those same low frequencies (PDT-EAS, n = 20). After performing comprehensive genetic testing with a panel of 237 genes, we found that genetic factors can explain a significant proportion of both PDT-EC and PDT-EAS hearing losses, accounting, respectively, for approx. one-fifth and one-half of all the cases in our cohort. Most of the causative variants were located in dominant and recessive genes previously linked to PD, but more than half of the variants were novel. Among the contributors to PDT-EC we identified OSBPL2 and SYNE4, two relatively new hereditary hearing loss genes with a low publication profile. Our study revealed that, for all PD patients, a postlingual hearing loss more severe in the low-frequency range is associated with a higher detection rate of causative variants. Isolating a genetic cause of PD is important in terms of prognosis, therapeutic effectiveness, and risk of recurrence.
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Acharya A, Schrauwen I, Leal SM. Identification of autosomal recessive nonsyndromic hearing impairment genes through the study of consanguineous and non-consanguineous families: past, present, and future. Hum Genet 2022; 141:413-430. [PMID: 34291353 PMCID: PMC10416318 DOI: 10.1007/s00439-021-02309-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 06/24/2021] [Indexed: 10/20/2022]
Abstract
Hearing impairment (HI) is one of the most common sensory disabilities with exceptionally high genetic heterogeneity. Of genetic HI cases, 30% are syndromic and 70% are nonsyndromic. For nonsyndromic (NS) HI, 77% of the cases are due to autosomal recessive (AR) inheritance. ARNSHI is usually congenital/prelingual, severe-to-profound, affects all frequencies and is not progressive. Thus far, 73 ARNSHI genes have been identified. Populations with high rates of consanguinity have been crucial in the identification of ARNSHI genes, and 92% (67/73) of these genes were identified in consanguineous families. Recent changes in genomic technologies and analyses have allowed a shift towards ARNSHI gene discovery in outbred populations. The latter is crucial towards understanding the genetic architecture of ARNSHI in diverse and understudied populations. We present an overview of the 73 ARNSHI genes, the methods used to identify them, including next-generation sequencing which revolutionized the field, and new technologies that show great promise in advancing ARNSHI discoveries.
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Affiliation(s)
- Anushree Acharya
- Center for Statistical Genetics, Gertrude H. Sergievsky Center, Columbia University Medical Center, New York, NY, USA
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Isabelle Schrauwen
- Center for Statistical Genetics, Gertrude H. Sergievsky Center, Columbia University Medical Center, New York, NY, USA
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Suzanne M Leal
- Center for Statistical Genetics, Gertrude H. Sergievsky Center, Columbia University Medical Center, New York, NY, USA.
- Department of Neurology, Columbia University Medical Center, New York, NY, USA.
- Taub Institute for Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA.
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13
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Shalaby KE, Aouida M, Gupta V, Ghanem SS, El-Agnaf OMA. Rapid Assessment of CRISPR Transfection Efficiency and Enrichment of CRISPR Induced Mutations Using a Dual-Fluorescent Stable Reporter System. Front Genome Ed 2022; 4:854866. [PMID: 35386234 PMCID: PMC8978543 DOI: 10.3389/fgeed.2022.854866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 02/15/2022] [Indexed: 11/30/2022] Open
Abstract
The nuclease activity of the CRISPR-Cas9 system relies on the delivery of a CRISPR-associated protein 9 (Cas9) and a single guide RNA (sgRNA) against the target gene. CRISPR components are typically delivered to cells as either a Cas9/sgRNA ribonucleoprotein (RNP) complex or a plasmid encoding a Cas9 protein along with a sequence-specific sgRNA. Multiple transfection reagents are known to deliver CRISPR-Cas9 components, and delivery vectors are being developed for different purposes by several groups. Here, we repurposed a dual-fluorescence (RFP-GFP-GFP) reporter system to quantify the uptake level of the functional CRISPR-Cas9 components into cells and compare the efficiency of CRISPR delivery vectors. Using this system, we developed a novel and rapid cell-based microplate reader assay that makes possible real-time, rapid, and high throughput quantification of CRISPR nuclease activity. Cells stably expressing this dual-fluorescent reporter construct facilitated a direct quantification of the level of the internalized and functional CRISPR-Cas9 molecules into the cells without the need of co-transfecting fluorescently labeled reporter molecules. Additionally, targeting a reporter gene integrated into the genome recapitulates endogenous gene targeting. Thus, this reporter could be used to optimize various transfection conditions of CRISPR components, to evaluate and compare the efficiency of transfection agents, and to enrich cells containing desired CRISPR-induced mutations.
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Affiliation(s)
- Karim E. Shalaby
- Biological and Biomedical Sciences Division, College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Mustapha Aouida
- Biological and Biomedical Sciences Division, College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
- *Correspondence: Mustapha Aouida, ; Omar M. A. El-Agnaf,
| | - Vijay Gupta
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Simona S. Ghanem
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Omar M. A. El-Agnaf
- Biological and Biomedical Sciences Division, College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
- *Correspondence: Mustapha Aouida, ; Omar M. A. El-Agnaf,
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14
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Hernández-Guzmán C, Gallego-Gutiérrez H, Chávez-Munguía B, Martín-Tapia D, González-Mariscal L. Zonula occludens 2 and Cell-Cell Contacts Are Required for Normal Nuclear Shape in Epithelia. Cells 2021; 10:cells10102568. [PMID: 34685547 PMCID: PMC8534263 DOI: 10.3390/cells10102568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/04/2021] [Accepted: 09/06/2021] [Indexed: 01/10/2023] Open
Abstract
MAGUK protein ZO-2 is present at tight junctions (TJs) and nuclei. In MDCK ZO-2 knockdown (KD) cells, nuclei exhibit an irregular shape with lobules and indentations. This condition correlates with an increase in DNA double strand breaks, however cells are not senescent and instead become resistant to UV-induced senescence. The irregular nuclear shape is also observed in isolated cells and in those without TJs, due to the lack of extracellular calcium. The aberrant nuclear shape of ZO-2 KD cells is not accompanied by a reduced expression of lamins A/C and B and lamin B receptors. Instead, it involves a decrease in constitutive and facultative heterochromatin, and microtubule instability that is restored with docetaxel. ZO-2 KD cells over-express SUN-1 that crosses the inner nuclear membrane and connects the nucleoskeleton of lamin A to nesprins, which traverse the outer nuclear membrane. Nesprins-3 and -4 that indirectly bind on their cytoplasmic face to vimentin and microtubules, respectively, are also over-expressed in ZO-2 KD cells, whereas vimentin is depleted. SUN-1 and lamin B1 co-immunoprecipitate with ZO-2, and SUN-1 associates to ZO-2 in a pull-down assay. Our results suggest that ZO-2 forms a complex with SUN-1 and lamin B1 at the inner nuclear membrane, and that ZO-2 and cell–cell contacts are required for a normal nuclear shape.
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Affiliation(s)
- Christian Hernández-Guzmán
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Ave IPN 2508, Mexico City 07360, Mexico; (C.H.-G.); (H.G.-G.); (D.M.-T.)
| | - Helios Gallego-Gutiérrez
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Ave IPN 2508, Mexico City 07360, Mexico; (C.H.-G.); (H.G.-G.); (D.M.-T.)
| | - Bibiana Chávez-Munguía
- Center for Research and Advanced Studies (Cinvestav), Department of Infectomics and Molecular Pathogenesis, Ave IPN 2508, Mexico City 07360, Mexico;
| | - Dolores Martín-Tapia
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Ave IPN 2508, Mexico City 07360, Mexico; (C.H.-G.); (H.G.-G.); (D.M.-T.)
| | - Lorenza González-Mariscal
- Center for Research and Advanced Studies (Cinvestav), Department of Physiology, Biophysics and Neuroscience, Ave IPN 2508, Mexico City 07360, Mexico; (C.H.-G.); (H.G.-G.); (D.M.-T.)
- Correspondence: ; Tel.: +52-55-5747-3966
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15
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van Ingen MJA, Kirby TJ. LINCing Nuclear Mechanobiology With Skeletal Muscle Mass and Function. Front Cell Dev Biol 2021; 9:690577. [PMID: 34368139 PMCID: PMC8335485 DOI: 10.3389/fcell.2021.690577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 06/25/2021] [Indexed: 11/13/2022] Open
Abstract
Skeletal muscle demonstrates a high degree of adaptability in response to changes in mechanical input. The phenotypic transformation in response to mechanical cues includes changes in muscle mass and force generating capabilities, yet the molecular pathways that govern skeletal muscle adaptation are still incompletely understood. While there is strong evidence that mechanotransduction pathways that stimulate protein synthesis play a key role in regulation of muscle mass, there are likely additional mechano-sensitive mechanisms important for controlling functional muscle adaptation. There is emerging evidence that the cell nucleus can directly respond to mechanical signals (i.e., nuclear mechanotransduction), providing a potential additional level of cellular regulation for controlling skeletal muscle mass. The importance of nuclear mechanotransduction in cellular function is evident by the various genetic diseases that arise from mutations in proteins crucial to the transmission of force between the cytoskeleton and the nucleus. Intriguingly, these diseases preferentially affect cardiac and skeletal muscle, suggesting that nuclear mechanotransduction is critically important for striated muscle homeostasis. Here we discuss our current understanding for how the nucleus acts as a mechanosensor, describe the main cytoskeletal and nuclear proteins involved in the process, and propose how similar mechanoresponsive mechanisms could occur in the unique cellular environment of a myofiber. In addition, we examine how nuclear mechanotransduction fits into our current framework for how mechanical stimuli regulates skeletal muscle mass.
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Affiliation(s)
- Maria J A van Ingen
- Biomolecular Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Tyler J Kirby
- Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam Movement Sciences, Amsterdam UMC, Amsterdam, Netherlands
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16
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The SUN2-nesprin-2 LINC complex and KIF20A function in the Golgi dispersal. Sci Rep 2021; 11:5358. [PMID: 33686165 PMCID: PMC7940470 DOI: 10.1038/s41598-021-84750-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 02/12/2021] [Indexed: 01/31/2023] Open
Abstract
The morphology of the Golgi complex is influenced by the cellular context, which strictly correlates with nuclear functions; however, the mechanism underlying this association remains elusive. The inner nuclear membrane SUN proteins, SUN1 and SUN2, have diverse functions together with the outer nuclear membrane nesprin proteins, which comprise the LINC complex. We found that depletion of SUN1 leads to Golgi complex dispersion with maintenance of ministacks and retained function for vesicle transport through the Golgi complex. In addition, SUN2 associates with microtubule plus-end-directed motor KIF20A, possibly via nesprin-2. KIF20A plays a role in the Golgi dispersion in conjunction with the SUN2-nesprin-2 LINC complex in SUN1-depleted cells, suggesting that SUN1 suppresses the function of the SUN2-nesprin-2 LINC complex under a steady-state condition. Further, SUN1-knockout mice, which show impaired cerebellar development and cerebellar ataxia, presented altered Golgi morphology in Purkinje cells. These findings revealed a regulation of the Golgi organization by the LINC complex.
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17
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Flores J, Takvorian PM, Weiss LM, Cali A, Gao N. Human microsporidian pathogen Encephalitozoon intestinalis impinges on enterocyte membrane trafficking and signaling. J Cell Sci 2021; 134:jcs253757. [PMID: 33589497 PMCID: PMC7938802 DOI: 10.1242/jcs.253757] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 02/01/2021] [Indexed: 12/23/2022] Open
Abstract
Microsporidia are a large phylum of obligate intracellular parasites. Approximately a dozen species of microsporidia infect humans, where they are responsible for a variety of diseases and occasionally death, especially in immunocompromised individuals. To better understand the impact of microsporidia on human cells, we infected human colonic Caco2 cells with Encephalitozoon intestinalis, and showed that these enterocyte cultures can be used to recapitulate the life cycle of the parasite, including the spread of infection with infective spores. Using transmission electron microscopy, we describe this lifecycle and demonstrate nuclear, mitochondrial and microvillar alterations by this pathogen. We also analyzed the transcriptome of infected cells to reveal host cell signaling alterations upon infection. These high-resolution imaging and transcriptional profiling analysis shed light on the impact of the microsporidial infection on its primary human target cell type.This article has an associated First Person interview with the first authors of the paper.
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Affiliation(s)
- Juan Flores
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102, USA
| | - Peter M Takvorian
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102, USA
- Departments of Medicine and Pathology, Albert Einstein College of Medicine Bronx, New York 10461, USA
| | - Louis M Weiss
- Departments of Medicine and Pathology, Albert Einstein College of Medicine Bronx, New York 10461, USA
| | - Ann Cali
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102, USA
| | - Nan Gao
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102, USA
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18
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Taiber S, Cohen R, Yizhar‐Barnea O, Sprinzak D, Holt JR, Avraham KB. Neonatal AAV gene therapy rescues hearing in a mouse model of SYNE4 deafness. EMBO Mol Med 2021; 13:e13259. [PMID: 33350593 PMCID: PMC7863404 DOI: 10.15252/emmm.202013259] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 11/10/2020] [Accepted: 11/18/2020] [Indexed: 12/21/2022] Open
Abstract
Genetic variants account for approximately half the cases of congenital and early-onset deafness. Methods and technologies for viral delivery of genes into the inner ear have evolved over the past decade to render gene therapy a viable and attractive approach for treatment. Variants in SYNE4, encoding the protein nesprin-4, a member of the linker of nucleoskeleton and cytoskeleton (LINC), lead to DFNB76 human deafness. Syne4-/- mice have severe-to-profound progressive hearing loss and exhibit mislocalization of hair cell nuclei and hair cell degeneration. We used AAV9-PHP.B, a recently developed synthetic adeno-associated virus, to deliver the coding sequence of Syne4 into the inner ears of neonatal Syne4-/- mice. Here we report rescue of hair cell morphology and survival, nearly complete recovery of auditory function, and restoration of auditory-associated behaviors, without observed adverse effects. Uncertainties remain regarding the durability of the treatment and the time window for intervention in humans, but our results suggest that gene therapy has the potential to prevent hearing loss in humans with SYNE4 mutations.
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Affiliation(s)
- Shahar Taiber
- Department of Human Molecular Genetics & BiochemistrySackler Faculty of Medicine & Sagol School of NeuroscienceTel Aviv UniversityTel AvivIsrael
| | - Roie Cohen
- School of Neurobiology, Biochemistry and BiophysicsGeorge S. Wise Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael
| | - Ofer Yizhar‐Barnea
- Department of Human Molecular Genetics & BiochemistrySackler Faculty of Medicine & Sagol School of NeuroscienceTel Aviv UniversityTel AvivIsrael
| | - David Sprinzak
- School of Neurobiology, Biochemistry and BiophysicsGeorge S. Wise Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael
| | - Jeffrey R Holt
- Departments of Otolaryngology & NeurologyBoston Children’s Hospital & Harvard Medical SchoolBostonMAUSA
| | - Karen B Avraham
- Department of Human Molecular Genetics & BiochemistrySackler Faculty of Medicine & Sagol School of NeuroscienceTel Aviv UniversityTel AvivIsrael
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19
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Gurusaran M, Davies OR. A molecular mechanism for LINC complex branching by structurally diverse SUN-KASH 6:6 assemblies. eLife 2021; 10:60175. [PMID: 33393904 PMCID: PMC7800377 DOI: 10.7554/elife.60175] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 01/03/2021] [Indexed: 12/11/2022] Open
Abstract
The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex mechanically couples cytoskeletal and nuclear components across the nuclear envelope to fulfil a myriad of cellular functions, including nuclear shape and positioning, hearing, and meiotic chromosome movements. The canonical model is that 3:3 interactions between SUN and KASH proteins underlie the nucleocytoskeletal linkages provided by the LINC complex. Here, we provide crystallographic and biophysical evidence that SUN-KASH is a constitutive 6:6 complex in which two constituent 3:3 complexes interact head-to-head. A common SUN-KASH topology is achieved through structurally diverse 6:6 interaction mechanisms by distinct KASH proteins, including zinc-coordination by Nesprin-4. The SUN-KASH 6:6 interface provides a molecular mechanism for the establishment of integrative and distributive connections between 3:3 structures within a branched LINC complex network. In this model, SUN-KASH 6:6 complexes act as nodes for force distribution and integration between adjacent SUN and KASH molecules, enabling the coordinated transduction of large forces across the nuclear envelope.
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Affiliation(s)
- Manickam Gurusaran
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom.,Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, United Kingdom
| | - Owen Richard Davies
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom.,Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, United Kingdom
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20
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O'Bryan CS, Zhang Q, Lele TP, Angelini TE. Mechanical Characterization of Glandular Acini Using a Micro-indentation Instrument. Bio Protoc 2020; 10:e3847. [PMID: 33889659 DOI: 10.21769/bioprotoc.3847] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 10/09/2020] [Indexed: 11/02/2022] Open
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex is responsible for tethering the nucleus to the cytoskeleton, providing a pathway for the cell's nucleus to sense mechanical signals from the environment. Recently, we explored the role of the LINC complex in the development of glandular epithelial acini, such as those found in kidneys, breasts, and other organs. Acini developed with disrupted LINC complexes exhibited a loss of structural integrity, including filling of the lumen structures. As part of our investigation, we performed a mechanical indentation assay of LINC disrupted and undisrupted MDCK II cells using a micro-indentation instrument mounted above a laser-scanning confocal microscope. Through a combination of force measurements acquired from the micro-indentation instrument and contact area measurements taken from fluorescence images, we determined the average contact pressure at which the acini structure ruptured. Here, we provide a detailed description of the design of the micro-indentation instrument, as well as the experimental steps developed to perform these bio-indentation measurements. Furthermore, we discuss the data analysis steps necessary to determine the rupture pressure of the acini structures. While this protocol is focused on the indentation of individual glandular acini, the methods presented here can be adapted to perform a variety of mechanical indentation experiments for both 2D and 3D biological systems.
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Affiliation(s)
- Christopher S O'Bryan
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL, USA.,Department of Chemical and Biological Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Qiao Zhang
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Thomas E Angelini
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL, USA.,J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
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21
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Kmonickova V, Frolikova M, Steger K, Komrskova K. The Role of the LINC Complex in Sperm Development and Function. Int J Mol Sci 2020; 21:E9058. [PMID: 33260574 PMCID: PMC7730847 DOI: 10.3390/ijms21239058] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 11/23/2022] Open
Abstract
The LINC (LInker of Nucleoskeleton and Cytoskeleton) complex is localized within the nuclear envelope and consists of SUN (Sad1/UNc84 homology domain-containing) proteins located in the inner nuclear membrane and KASH (Klarsicht/Anc1/Syne1 homology domain-containing) proteins located in the outer nuclear membrane, hence linking nuclear with cytoplasmic structures. While the nucleoplasm-facing side acts as a key player for correct pairing of homolog chromosomes and rapid chromosome movements during meiosis, the cytoplasm-facing side plays a pivotal role for sperm head development and proper acrosome formation during spermiogenesis. A further complex present in spermatozoa is involved in head-to-tail coupling. An intact LINC complex is crucial for the production of fertile sperm, as mutations in genes encoding for complex proteins are known to be associated with male subfertility in both mice and men. The present review provides a comprehensive overview on our current knowledge of LINC complex subtypes present in germ cells and its central role for male reproduction. Future studies on distinct LINC complex components are an absolute requirement to improve the diagnosis of idiopathic male factor infertility and the outcome of assisted reproduction.
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Affiliation(s)
- Vera Kmonickova
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 252 50 Vestec, Czech Republic; (V.K.); (M.F.)
| | - Michaela Frolikova
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 252 50 Vestec, Czech Republic; (V.K.); (M.F.)
| | - Klaus Steger
- Department of Urology, Pediatric Urology and Andrology, Molecular Andrology, Justus-Liebig University, 35392 Giessen, Germany;
| | - Katerina Komrskova
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 252 50 Vestec, Czech Republic; (V.K.); (M.F.)
- Department of Zoology, Faculty of Science, Charles University, Vinicna 7, 128 44 Prague 2, Czech Republic
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22
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Vona B, Doll J, Hofrichter MAH, Haaf T, Varshney GK. Small fish, big prospects: using zebrafish to unravel the mechanisms of hereditary hearing loss. Hear Res 2020; 397:107906. [PMID: 32063424 PMCID: PMC7415493 DOI: 10.1016/j.heares.2020.107906] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/13/2020] [Accepted: 01/29/2020] [Indexed: 12/16/2022]
Abstract
Over the past decade, advancements in high-throughput sequencing have greatly enhanced our knowledge of the mutational signatures responsible for hereditary hearing loss. In its present state, the field has a largely uncensored view of protein coding changes in a growing number of genes that have been associated with hereditary hearing loss, and many more that have been proposed as candidate genes. Sequencing data can now be generated using methods that have become widespread and affordable. The greatest hurdles facing the field concern functional validation of uncharacterized genes and rapid application to human diseases, including hearing and balance disorders. To date, over 30 hearing-related disease models exist in zebrafish. New genome editing technologies, including CRISPR/Cas9 will accelerate the functional validation of hearing loss genes and variants in zebrafish. Here, we discuss current progress in the field and recent advances in genome editing approaches.
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Affiliation(s)
- Barbara Vona
- Department of Otolaryngology--Head & Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, Tübingen, Germany.
| | - Julia Doll
- Institute of Human Genetics, Julius Maximilians University, Würzburg, Germany
| | | | - Thomas Haaf
- Institute of Human Genetics, Julius Maximilians University, Würzburg, Germany
| | - Gaurav K Varshney
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States.
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23
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Nadar-Ponniah PT, Taiber S, Caspi M, Koffler-Brill T, Dror AA, Siman-Tov R, Rubinstein M, Padmanabhan K, Luxenburg C, Lang RA, Avraham KB, Rosin-Arbesfeld R. Striatin Is Required for Hearing and Affects Inner Hair Cells and Ribbon Synapses. Front Cell Dev Biol 2020; 8:615. [PMID: 32766247 PMCID: PMC7381154 DOI: 10.3389/fcell.2020.00615] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/22/2020] [Indexed: 12/22/2022] Open
Abstract
Striatin, a subunit of the serine/threonine phosphatase PP2A, is a core member of the conserved striatin-interacting phosphatase and kinase (STRIPAK) complexes. The protein is expressed in the cell junctions between epithelial cells, which play a role in maintaining cell-cell adhesion. Since the cell junctions are crucial for the function of the mammalian inner ear, we examined the localization and function of striatin in the mouse cochlea. Our results show that in neonatal mice, striatin is specifically expressed in the cell-cell junctions of the inner hair cells, the receptor cells in the mammalian cochlea. Auditory brainstem response measurements of striatin-deficient mice indicated a progressive, high-frequency hearing loss, suggesting that striatin is essential for normal hearing. Moreover, scanning electron micrographs of the organ of Corti revealed a moderate degeneration of the outer hair cells in the middle and basal regions, concordant with the high-frequency hearing loss. Additionally, striatin-deficient mice show aberrant ribbon synapse maturation. Loss of the outer hair cells, combined with the aberrant ribbon synapse distribution, may lead to the observed auditory impairment. Together, these results suggest a novel function for striatin in the mammalian auditory system.
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Affiliation(s)
- Prathamesh T. Nadar-Ponniah
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shahar Taiber
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Michal Caspi
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tal Koffler-Brill
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Amiel A. Dror
- Department of Otolaryngology, Head and Neck Surgery, Galilee Medical Center, Nahariya, Israel
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Ronen Siman-Tov
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Krishnanand Padmanabhan
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Chen Luxenburg
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Richard A. Lang
- Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Karen B. Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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24
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Davidson PM, Battistella A, Déjardin T, Betz T, Plastino J, Borghi N, Cadot B, Sykes C. Nesprin-2 accumulates at the front of the nucleus during confined cell migration. EMBO Rep 2020; 21:e49910. [PMID: 32419336 DOI: 10.15252/embr.201949910] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/15/2020] [Accepted: 04/21/2020] [Indexed: 12/12/2022] Open
Abstract
The mechanisms by which cells exert forces on their nuclei to migrate through openings smaller than the nuclear diameter remain unclear. We use CRISPR/Cas9 to fluorescently label nesprin-2 giant, which links the cytoskeleton to the nuclear interior. We demonstrate that nesprin-2 accumulates at the front of the nucleus during nuclear deformation through narrow constrictions, independently of the nuclear lamina. We find that nesprins are mobile at time scales similar to the accumulation. Using artificial constructs, we show that the actin-binding domain of nesprin-2 is necessary and sufficient for this accumulation. Actin filaments are organized in a barrel structure around the nucleus in the direction of movement. Using two-photon ablation and cytoskeleton-inhibiting drugs, we demonstrate an actomyosin-dependent pulling force on the nucleus from the front of the cell. The elastic recoil upon ablation is dampened when nesprins are reduced at the nuclear envelope. We thus show that actin redistributes nesprin-2 giant toward the front of the nucleus and contributes to pulling the nucleus through narrow constrictions, in concert with myosin.
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Affiliation(s)
- Patricia M Davidson
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France.,Center for Research in Myology, INSERM UMR974, Sorbonne Université, Paris, France
| | - Aude Battistella
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France
| | - Théophile Déjardin
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France.,Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, France
| | - Timo Betz
- Institute of Cell Biology, ZMBE, Münster, Germany
| | - Julie Plastino
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France
| | - Nicolas Borghi
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, France
| | - Bruno Cadot
- Center for Research in Myology, INSERM UMR974, Sorbonne Université, Paris, France
| | - Cécile Sykes
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France
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25
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Lee S, Dondzillo A, Gubbels SP, Raphael Y. Practical aspects of inner ear gene delivery for research and clinical applications. Hear Res 2020; 394:107934. [PMID: 32204962 DOI: 10.1016/j.heares.2020.107934] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 02/26/2020] [Accepted: 02/28/2020] [Indexed: 12/24/2022]
Abstract
The application of gene therapy is widely expanding in research and continuously improving in preparation for clinical applications. The inner ear is an attractive target for gene therapy for treating environmental and genetic diseases in both the auditory and vestibular systems. With the lack of spontaneous cochlear hair cell replacement, hair cell regeneration in adult mammals is among the most important goals of gene therapy. In addition, correcting gene defects can open up a new era for treating inner ear diseases. The relative isolation and small size of the inner ear dictate local administration routes and carefully calculated small volumes of reagents. In the current review, we will cover effective timing, injection routes and types of vectors for successful gene delivery to specific target cells within the inner ear. Differences between research purposes and clinical applications are also discussed.
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Affiliation(s)
- Sungsu Lee
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, Michigan Medicine, Ann Arbor, MI, USA
| | - Anna Dondzillo
- Department of Otolaryngology, Head and Neck Surgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Samuel P Gubbels
- Department of Otolaryngology, Head and Neck Surgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Yehoash Raphael
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, Michigan Medicine, Ann Arbor, MI, USA.
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26
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Extranuclear Structural Components that Mediate Dynamic Chromosome Movements in Yeast Meiosis. Curr Biol 2020; 30:1207-1216.e4. [PMID: 32059771 DOI: 10.1016/j.cub.2020.01.054] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 11/20/2019] [Accepted: 01/16/2020] [Indexed: 02/02/2023]
Abstract
Telomere-led rapid chromosome movements or rapid prophase movements direct fundamental meiotic processes required for successful haploidization of the genome. Critical components of the machinery that generates rapid prophase movements are unknown, and the mechanism underlying rapid prophase movements remains poorly understood. We identified S. cerevisiae Mps2 as the outer nuclear membrane protein that connects the LINC complex with the cytoskeleton. We also demonstrate that the motor Myo2 works together with Mps2 to couple the telomeres to the actin cytoskeleton. Further, we show that Csm4 interacts with Mps2 and is required for perinuclear localization of Myo2, implicating Csm4 as a regulator of the Mps2-Myo2 interaction. We propose a model in which the newly identified functions of Mps2 and Myo2 cooperate with Csm4 to drive chromosome movements in meiotic prophase by coupling telomeres to the actin cytoskeleton.
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27
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Evans JJ, Alkaisi MM, Sykes PH. Tumour Initiation: a Discussion on Evidence for a "Load-Trigger" Mechanism. Cell Biochem Biophys 2019; 77:293-308. [PMID: 31598831 PMCID: PMC6841748 DOI: 10.1007/s12013-019-00888-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 09/23/2019] [Indexed: 12/18/2022]
Abstract
Appropriate mechanical forces on cells are vital for normal cell behaviour and this review discusses the possibility that tumour initiation depends partly on the disruption of the normal physical architecture of the extracellular matrix (ECM) around a cell. The alterations that occur thence promote oncogene expression. Some questions, that are not answered with certainty by current consensus mechanisms of tumourigenesis, are elegantly explained by the triggering of tumours being a property of the physical characteristics of the ECM, which is operative following loading of the tumour initiation process with a relevant gene variant. Clinical observations are consistent with this alternative hypothesis which is derived from studies that have, together, accumulated an extensive variety of data incorporating biochemical, genetic and clinical findings. Thus, this review provides support for the view that the ECM may have an executive function in induction of a tumour. Overall, reported observations suggest that either restoring an ECM associated with homeostasis or targeting the related signal transduction mechanisms may possibly be utilised to modify or control the early progression of cancers. The review provides a coherent template for discussing the notion, in the context of contemporary knowledge, that tumourigenesis is an alliance of biochemistry, genetics and biophysics, in which the physical architecture of the ECM may be a fundamental component. For more definitive clarification of the concept there needs to be a phalanx of experiments conceived around direct questions that are raised by this paper.
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Affiliation(s)
- John J Evans
- Department of Obstetrics and Gynaecology, University of Otago Christchurch, Christchurch, New Zealand.
- MacDiarmid Institute of Advanced Materials and Nanotechnology, Christchurch, New Zealand.
| | - Maan M Alkaisi
- MacDiarmid Institute of Advanced Materials and Nanotechnology, Christchurch, New Zealand
- Department of Electrical and Computer Engineering, University of Canterbury, Christchurch, New Zealand
| | - Peter H Sykes
- Department of Obstetrics and Gynaecology, University of Otago Christchurch, Christchurch, New Zealand
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28
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Sneider A, Hah J, Wirtz D, Kim DH. Recapitulation of molecular regulators of nuclear motion during cell migration. Cell Adh Migr 2019; 13:50-62. [PMID: 30261154 PMCID: PMC6527386 DOI: 10.1080/19336918.2018.1506654] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/05/2018] [Accepted: 07/18/2018] [Indexed: 01/12/2023] Open
Abstract
Cell migration is a highly orchestrated cellular event that involves physical interactions of diverse subcellular components. The nucleus as the largest and stiffest organelle in the cell not only maintains genetic functionality, but also actively changes its morphology and translocates through dynamic formation of nucleus-bound contractile stress fibers. Nuclear motion is an active and essential process for successful cell migration and nucleus self-repairs in response to compression and extension forces in complex cell microenvironment. This review recapitulates molecular regulators that are crucial for nuclear motility during cell migration and highlights recent advances in nuclear deformation-mediated rupture and repair processes in a migrating cell.
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Affiliation(s)
- Alexandra Sneider
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Jungwon Hah
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea
| | - Denis Wirtz
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Dong-Hwee Kim
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea
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29
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Loo TH, Ye X, Chai RJ, Ito M, Bonne G, Ferguson-Smith AC, Stewart CL. The mammalian LINC complex component SUN1 regulates muscle regeneration by modulating drosha activity. eLife 2019; 8:e49485. [PMID: 31686651 PMCID: PMC6853637 DOI: 10.7554/elife.49485] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/27/2019] [Indexed: 01/13/2023] Open
Abstract
Here we show that a major muscle specific isoform of the murine LINC complex protein SUN1 is required for efficient muscle regeneration. The nucleoplasmic domain of the isoform specifically binds to and inhibits Drosha, a key component of the microprocessor complex required for miRNA synthesis. Comparison of the miRNA profiles between wildtype and SUN1 null myotubes identified a cluster of miRNAs encoded by a non-translated retrotransposon-like one antisense (Rtl1as) transcript that are decreased in the WT myoblasts due to SUN1 inhibition of Drosha. One of these miRNAs miR-127 inhibits the translation of the Rtl1 sense transcript, that encodes the retrotransposon-like one protein (RTL1), which is also required for muscle regeneration and is expressed in regenerating/dystrophic muscle. The LINC complex may therefore regulate gene expression during muscle regeneration by controlling miRNA processing. This provides new insights into the molecular pathology underlying muscular dystrophies and how the LINC complex may regulate mechanosignaling.
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Affiliation(s)
- Tsui Han Loo
- Developmental and Regenerative BiologyInstitute of Medical BiologySingaporeSingapore
| | - Xiaoqian Ye
- Developmental and Regenerative BiologyInstitute of Medical BiologySingaporeSingapore
| | - Ruth Jinfen Chai
- Developmental and Regenerative BiologyInstitute of Medical BiologySingaporeSingapore
| | - Mitsuteru Ito
- Department of GeneticsUniversity of CambridgeCambridgeUnited Kingdom
| | - Gisèle Bonne
- Center of Research in Myology, Institut de MyologieSorbonne Universités, UPMC Univ Paris 06, INSERM UMRS 974, CNRS FRE 3617ParisFrance
| | | | - Colin L Stewart
- Developmental and Regenerative BiologyInstitute of Medical BiologySingaporeSingapore
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30
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Starr DA. A network of nuclear envelope proteins and cytoskeletal force generators mediates movements of and within nuclei throughout Caenorhabditis elegans development. Exp Biol Med (Maywood) 2019; 244:1323-1332. [PMID: 31495194 PMCID: PMC6880151 DOI: 10.1177/1535370219871965] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Nuclear migration and anchorage, together referred to as nuclear positioning, are central to many cellular and developmental events. Nuclear positioning is mediated by a conserved network of nuclear envelope proteins that interacts with force generators in the cytoskeleton. At the heart of this network are li nker of n ucleoskeleton and c ytoskeleton (LINC) complexes made of S ad1 and UN C-84 (SUN) proteins at the inner nuclear membrane and K larsicht, A NC-1, and S yne homology (KASH) proteins in the outer nuclear membrane. LINC complexes span the nuclear envelope, maintain nuclear envelope architecture, designate the surface of nuclei distinctly from the contiguous endoplasmic reticulum, and were instrumental in the early evolution of eukaryotes. LINC complexes interact with lamins in the nucleus and with various cytoplasmic KASH effectors from the surface of nuclei. These effectors regulate the cytoskeleton, leading to a variety of cellular outputs including pronuclear migration, nuclear migration through constricted spaces, nuclear anchorage, centrosome attachment to nuclei, meiotic chromosome movements, and DNA damage repair. How LINC complexes are regulated and how they function are reviewed here. The focus is on recent studies elucidating the best-understood network of LINC complexes, those used throughout Caenorhabditis elegans development.
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Affiliation(s)
- Daniel A Starr
- Department of Molecular and Cellular Biology,
University of California, Davis, CA 95616, USA
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31
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Zhang Q, Narayanan V, Mui KL, O'Bryan CS, Anderson RH, Kc B, Cabe JI, Denis KB, Antoku S, Roux KJ, Dickinson RB, Angelini TE, Gundersen GG, Conway DE, Lele TP. Mechanical Stabilization of the Glandular Acinus by Linker of Nucleoskeleton and Cytoskeleton Complex. Curr Biol 2019; 29:2826-2839.e4. [PMID: 31402305 PMCID: PMC6736724 DOI: 10.1016/j.cub.2019.07.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 06/03/2019] [Accepted: 07/09/2019] [Indexed: 12/19/2022]
Abstract
The nucleoskeleton and cytoskeleton are important protein networks that govern cellular behavior and are connected together by the linker of nucleoskeleton and cytoskeleton (LINC) complex. Mutations in LINC complex components may be relevant to cancer, but how cell-level changes might translate into tissue-level malignancy is unclear. We used glandular epithelial cells in a three-dimensional culture model to investigate the effect of perturbations of the LINC complex on higher order cellular architecture. We show that inducible LINC complex disruption in human mammary epithelial MCF-10A cells and canine kidney epithelial MDCK II cells mechanically destabilizes the acinus. Lumenal collapse occurs because the acinus is unstable to increased mechanical tension that is caused by upregulation of Rho-kinase-dependent non-muscle myosin II motor activity. These findings provide a potential mechanistic explanation for how disruption of LINC complex may contribute to a loss of tissue structure in glandular epithelia.
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Affiliation(s)
- Qiao Zhang
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Vani Narayanan
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Keeley L Mui
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Christopher S O'Bryan
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA
| | | | - Birendra Kc
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Jolene I Cabe
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Kevin B Denis
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Susumu Antoku
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Kyle J Roux
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD 57104, USA; Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57105, USA
| | - Richard B Dickinson
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Thomas E Angelini
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Gregg G Gundersen
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Daniel E Conway
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA.
| | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA.
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32
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Östlund C, Chang W, Gundersen GG, Worman HJ. Pathogenic mutations in genes encoding nuclear envelope proteins and defective nucleocytoplasmic connections. Exp Biol Med (Maywood) 2019; 244:1333-1344. [PMID: 31299860 DOI: 10.1177/1535370219862243] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Mutations in genes encoding nuclear lamins and associated nuclear envelope proteins have been linked to a broad range of inherited diseases affecting different tissues and organs. These diseases are often referred to as laminopathies. Scientists have yet to elucidate exactly how pathogenic mutations leading to alteration of a nuclear envelope protein cause disease. Our relatively recent research has shown that pathogenic mutations in genes encoding nuclear envelope proteins lead to defective nucleocytoplasmic connections that disrupt proper functioning of the linker of nucleoskeleton and cytoskeleton complex in the establishment of cell polarity. These defects may explain, at least in part, pathogenic mechanisms underlying laminopathies.Impact statementMutations in genes encoding nuclear lamins and associated nuclear envelope proteins have been linked to several diseases affecting different tissues and organs. The pathogenic mechanisms underlying these diseases, often called laminopathies, remain poorly understood. Increased knowledge of the functions of different nuclear envelope proteins and the interactions between them is crucial to elucidate these disease mechanisms. Our research has shown that pathogenic mutations in genes encoding nuclear envelope proteins lead to defective nucleocytoplasmic connections that disrupt proper functioning of the linker of nucleoskeleton and cytoskeleton (LINC) complex in the establishment of cell polarity. These defects may contribute to the pathogenesis of laminopathies and provide novel targets for therapeutics.
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Affiliation(s)
- Cecilia Östlund
- Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Wakam Chang
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Gregg G Gundersen
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Howard J Worman
- Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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33
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Joukov V, De Nicolo A. The Centrosome and the Primary Cilium: The Yin and Yang of a Hybrid Organelle. Cells 2019; 8:E701. [PMID: 31295970 PMCID: PMC6678760 DOI: 10.3390/cells8070701] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/04/2019] [Accepted: 07/06/2019] [Indexed: 12/27/2022] Open
Abstract
Centrosomes and primary cilia are usually considered as distinct organelles, although both are assembled with the same evolutionary conserved, microtubule-based templates, the centrioles. Centrosomes serve as major microtubule- and actin cytoskeleton-organizing centers and are involved in a variety of intracellular processes, whereas primary cilia receive and transduce environmental signals to elicit cellular and organismal responses. Understanding the functional relationship between centrosomes and primary cilia is important because defects in both structures have been implicated in various diseases, including cancer. Here, we discuss evidence that the animal centrosome evolved, with the transition to complex multicellularity, as a hybrid organelle comprised of the two distinct, but intertwined, structural-functional modules: the centriole/primary cilium module and the pericentriolar material/centrosome module. The evolution of the former module may have been caused by the expanding cellular diversification and intercommunication, whereas that of the latter module may have been driven by the increasing complexity of mitosis and the requirement for maintaining cell polarity, individuation, and adhesion. Through its unique ability to serve both as a plasma membrane-associated primary cilium organizer and a juxtanuclear microtubule-organizing center, the animal centrosome has become an ideal integrator of extracellular and intracellular signals with the cytoskeleton and a switch between the non-cell autonomous and the cell-autonomous signaling modes. In light of this hypothesis, we discuss centrosome dynamics during cell proliferation, migration, and differentiation and propose a model of centrosome-driven microtubule assembly in mitotic and interphase cells. In addition, we outline the evolutionary benefits of the animal centrosome and highlight the hierarchy and modularity of the centrosome biogenesis networks.
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Affiliation(s)
- Vladimir Joukov
- N.N. Petrov National Medical Research Center of Oncology, 197758 Saint-Petersburg, Russia.
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34
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Jahed Z, Hao H, Thakkar V, Vu UT, Valdez VA, Rathish A, Tolentino C, Kim SCJ, Fadavi D, Starr DA, Mofrad MRK. Role of KASH domain lengths in the regulation of LINC complexes. Mol Biol Cell 2019; 30:2076-2086. [PMID: 30995155 PMCID: PMC6727767 DOI: 10.1091/mbc.e19-02-0079] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The linker of the nucleoskeleton and cytoskeleton (LINC) complex is formed by the conserved interactions between Sad-1 and UNC-84 (SUN) and Klarsicht, ANC-1, SYNE homology (KASH) domain proteins, providing a physical coupling between the nucleoskeleton and cytoskeleton that mediates the transfer of physical forces across the nuclear envelope. The LINC complex can perform distinct cellular functions by pairing various KASH domain proteins with the same SUN domain protein. For example, in Caenorhabditis elegans, SUN protein UNC-84 binds to two KASH proteins UNC-83 and ANC-1 to mediate nuclear migration and anchorage, respectively. In addition to distinct cytoplasmic domains, the luminal KASH domain also varies among KASH domain proteins of distinct functions. In this study, we combined in vivo C. elegans genetics and in silico molecular dynamics simulations to understand the relation between the length and amino acid composition of the luminal KASH domain, and the function of the SUN–KASH complex. We show that longer KASH domains can withstand and transfer higher forces and interact with the membrane through a conserved membrane proximal EEDY domain that is unique to longer KASH domains. In agreement with our models, our in vivo results show that swapping the KASH domains of ANC-1 and UNC-83, or shortening the KASH domain of ANC-1, both result in a nuclear anchorage defect in C. elegans.
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Affiliation(s)
- Zeinab Jahed
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Hongyan Hao
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Vyom Thakkar
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Uyen T Vu
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Venecia A Valdez
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Akshay Rathish
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Chris Tolentino
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Samuel C J Kim
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Darya Fadavi
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Daniel A Starr
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Mohammad R K Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720.,Molecular Biophysics and Integrative Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
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35
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Ingham NJ, Pearson SA, Vancollie VE, Rook V, Lewis MA, Chen J, Buniello A, Martelletti E, Preite L, Lam CC, Weiss FD, Powis Z, Suwannarat P, Lelliott CJ, Dawson SJ, White JK, Steel KP. Mouse screen reveals multiple new genes underlying mouse and human hearing loss. PLoS Biol 2019; 17:e3000194. [PMID: 30973865 PMCID: PMC6459510 DOI: 10.1371/journal.pbio.3000194] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 03/07/2019] [Indexed: 11/23/2022] Open
Abstract
Adult-onset hearing loss is very common, but we know little about the underlying molecular pathogenesis impeding the development of therapies. We took a genetic approach to identify new molecules involved in hearing loss by screening a large cohort of newly generated mouse mutants using a sensitive electrophysiological test, the auditory brainstem response (ABR). We review here the findings from this screen. Thirty-eight unexpected genes associated with raised thresholds were detected from our unbiased sample of 1,211 genes tested, suggesting extreme genetic heterogeneity. A wide range of auditory pathophysiologies was found, and some mutant lines showed normal development followed by deterioration of responses, revealing new molecular pathways involved in progressive hearing loss. Several of the genes were associated with the range of hearing thresholds in the human population and one, SPNS2, was involved in childhood deafness. The new pathways required for maintenance of hearing discovered by this screen present new therapeutic opportunities. This study uses an electrophysiological screen of over a thousand new mutant mouse lines to identify 38 new genes underlying deafness, some associated with human hearing function, revealing a wide range of molecular and pathological mechanisms. Progressive hearing loss with age is extremely common in the population, leading to difficulties in understanding speech, increased social isolation, and associated depression. We know it has a significant heritability, but so far we know very little about the molecular pathways leading to hearing loss, hampering the development of treatments. Here, we describe a large-scale screen of 1,211 new targeted mouse mutant lines, resulting in the identification of 38 genes underlying hearing loss that were not previously suspected of involvement in hearing. Some of these genes reveal molecular pathways that may be useful targets for drug development. Our further analysis of the genes identified and the varied pathological mechanisms within the ear resulting from the mutations suggests that hearing loss is an extremely heterogeneous disorder and may have as many as 1,000 genes involved.
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Affiliation(s)
- Neil J. Ingham
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | | | | | - Victoria Rook
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Morag A. Lewis
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Jing Chen
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Annalisa Buniello
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Elisa Martelletti
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Lorenzo Preite
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Chi Chung Lam
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Felix D. Weiss
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Zӧe Powis
- Department of Emerging Genetics Medicine, Ambry Genetics, Aliso Viejo, California, United States of America
| | - Pim Suwannarat
- Mid-Atlantic Permanente Medical Group, Rockville, Maryland, United States of America
| | | | - Sally J. Dawson
- UCL Ear Institute, University College London, London, United Kingdom
| | | | - Karen P. Steel
- Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
- * E-mail:
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36
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Jahed Z, Fadavi D, Vu UT, Asgari E, Luxton GWG, Mofrad MRK. Molecular Insights into the Mechanisms of SUN1 Oligomerization in the Nuclear Envelope. Biophys J 2019. [PMID: 29539404 DOI: 10.1016/j.bpj.2018.01.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The LINC complex is found in a wide variety of organisms and is formed by the transluminal interaction between outer- and inner-nuclear-membrane KASH and SUN proteins, respectively. Most extensively studied are SUN1 and SUN2 proteins, which are widely expressed in mammals. Although SUN1 and SUN2 play functionally redundant roles in several cellular processes, more recent studies have revealed diverse and distinct functions for SUN1. While several recent in vitro structural studies have revealed the molecular details of various fragments of SUN2, no such structural information is available for SUN1. Herein, we conduct a systematic analysis of the molecular relationships between SUN1 and SUN2, highlighting key similarities and differences that could lead to clues into their distinct functions. We use a wide range of computational tools, including multiple sequence alignments, homology modeling, molecular docking, and molecular dynamic simulations, to predict structural differences between SUN1 and SUN2, with the goal of understanding the molecular mechanisms underlying SUN1 oligomerization in the nuclear envelope. Our simulations suggest that the structural model of SUN1 is stable in a trimeric state and that SUN1 trimers can associate through their SUN domains to form lateral complexes. We also ask whether SUN1 could adopt an inactive monomeric conformation as seen in SUN2. Our results imply that the KASH binding domain of SUN1 is also inhibited in monomeric SUN1 but through weaker interactions than in monomeric SUN2.
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Affiliation(s)
- Zeinab Jahed
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, California
| | - Darya Fadavi
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, California
| | - Uyen T Vu
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, California
| | - Ehsaneddin Asgari
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, California
| | - G W Gant Luxton
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota
| | - Mohammad R K Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, California; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California.
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Abstract
Nuclear positioning plays an essential role in defining cell architecture and behaviour in both development and disease, and nuclear location frequently adjusts according to internal and external cues. For instance, during periods of migration in many cell types, the nucleus may be actively repositioned behind the microtubule-organising centre. Nuclear movement, for the most part, is dependent upon coupling of the cytoskeleton to the nuclear periphery. This is accomplished largely through SUN and KASH domain proteins, which together assemble to form LINC (linker of the nucleoskeleton and cytoskeleton) complexes spanning the nuclear envelope. SUN proteins of the inner nuclear membrane provide a connection to nuclear structures while acting as a tether for outer nuclear membrane KASH proteins. The latter contain binding sites for diverse cytoskeletal components. Recent publications highlight new aspects of LINC complex regulation revealing that the interplay between SUN and KASH partners can strongly influence how the nucleus functionally engages with different branches of the cytoskeleton.
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Affiliation(s)
- Brian Burke
- Institute for Medical Biology, 8A Biomedical Grove, #06-06 Immunos , 138648, Singapore
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38
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Carpena NT, Lee MY. Genetic Hearing Loss and Gene Therapy. Genomics Inform 2018; 16:e20. [PMID: 30602081 PMCID: PMC6440668 DOI: 10.5808/gi.2018.16.4.e20] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 12/04/2018] [Indexed: 12/15/2022] Open
Abstract
Genetic hearing loss crosses almost all the categories of hearing loss which includes the following: conductive, sensory, and neural; syndromic and nonsyndromic; congenital, progressive, and adult onset; high-frequency, low-frequency, or mixed frequency; mild or profound; and recessive, dominant, or sex-linked. Genes play a role in almost half of all cases of hearing loss but effective treatment options are very limited. Genetic hearing loss is considered to be extremely genetically heterogeneous. The advancements in genomics have been instrumental to the identification of more than 6,000 causative variants in more than 150 genes causing hearing loss. Identification of genes for hearing impairment provides an increased insight into the normal development and function of cells in the auditory system. These defective genes will ultimately be important therapeutic targets. However, the auditory system is extremely complex which requires tremendous advances in gene therapy including gene vectors, routes of administration, and therapeutic approaches. This review summarizes and discusses recent advances in elucidating the genomics of genetic hearing loss and technologies aimed at developing a gene therapy that may become a treatment option for in the near future.
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Affiliation(s)
- Nathanial T Carpena
- Department of Otolaryngology-Head and Neck Surgery, Dankook University College of Medicine, Cheonan 31116, Korea
| | - Min Young Lee
- Department of Otolaryngology-Head and Neck Surgery, Dankook University College of Medicine, Cheonan 31116, Korea.,Beckman Laser Institute Korea, Dankook University, Cheonan 31116, Korea
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39
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Abstract
ABSTRACT
The intracellular environment of eukaryotic cells is highly complex and compact. The limited volume of the cell, usually a few hundred femtoliters, is not only occupied by numerous complicated, diverse membranous and proteinaceous structures, these structures are also highly dynamic due to constant remodeling and trafficking events. Consequently, intracellular interactions are more than just opportunities to exchange molecules; they also involve components physically navigating around each other in a highly confined space. While the biochemical interactions between organelles have been intensely studied in the past decades, the mechanical properties of organelles and the physical interactions between them are only beginning to be unraveled. Indeed, recent studies show that intracellular organelles are, at times, under extreme mechanical strain both in widely used experimental systems as well as in vivo. In this Hypothesis, we highlight known examples of intracellular mechanical challenges in biological systems and focus on the coping mechanisms of two important organelles, the nucleus and mitochondria, for they are the best studied in this aspect. In the case of mitochondria, we propose that ER–mitochondrial contact sites at thin cell peripheries may induce mitochondrial fission by mechanically constricting mitochondrial tubules. We also briefly discuss the mechano-responsiveness of other organelles and interesting directions for future research.
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Affiliation(s)
- Qian Feng
- Institute of Biochemistry, ETH Zurich, 8093 Zürich, Switzerland
| | - Benoît Kornmann
- Institute of Biochemistry, ETH Zurich, 8093 Zürich, Switzerland
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40
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Lele TP, Dickinson RB, Gundersen GG. Mechanical principles of nuclear shaping and positioning. J Cell Biol 2018; 217:3330-3342. [PMID: 30194270 PMCID: PMC6168261 DOI: 10.1083/jcb.201804052] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/27/2018] [Accepted: 08/24/2018] [Indexed: 12/16/2022] Open
Abstract
Positioning and shaping the nucleus represents a mechanical challenge for the migrating cell because of its large size and resistance to deformation. Cells shape and position the nucleus by transmitting forces from the cytoskeleton onto the nuclear surface. This force transfer can occur through specialized linkages between the nuclear envelope and the cytoskeleton. In response, the nucleus can deform and/or it can move. Nuclear movement will occur when there is a net differential in mechanical force across the nucleus, while nuclear deformation will occur when mechanical forces overcome the mechanical resistance of the various structures that comprise the nucleus. In this perspective, we review current literature on the sources and magnitude of cellular forces exerted on the nucleus, the nuclear envelope proteins involved in transferring cellular forces, and the contribution of different nuclear structural components to the mechanical response of the nucleus to these forces.
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Affiliation(s)
- Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL .,Anatomy and Cell Biology, University of Florida, Gainesville, FL
| | | | - Gregg G Gundersen
- Department of Pathology and Cell Biology, Columbia University, New York, NY
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41
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Janin A, Gache V. Nesprins and Lamins in Health and Diseases of Cardiac and Skeletal Muscles. Front Physiol 2018; 9:1277. [PMID: 30245638 PMCID: PMC6137955 DOI: 10.3389/fphys.2018.01277] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/22/2018] [Indexed: 12/26/2022] Open
Abstract
Since the discovery of the inner nuclear transmembrane protein emerin in the early 1990s, nuclear envelope (NE) components and related involvement in nuclei integrity and functionality have been highly investigated. The NE is composed of two distinct lipid bilayers described as the inner (INM) and outer (ONM) nuclear membrane. NE proteins can be specifically “integrated” in the INM (such as emerin and SUN proteins) or in the ONM such as nesprins. Additionally, flanked to the INM, the nuclear lamina, a proteinaceous meshwork mainly composed of lamins A and C completes NE composition. This network of proteins physically interplays to guarantee NE integrity and most importantly, shape the bridge between cytoplasmic cytoskeletons networks (such as microtubules and actin) and the genome, through the anchorage to the heterochromatin. The essential network driving the connection of nucleoskeleton with cytoskeleton takes place in the perinuclear space (the space between ONM and INM) with the contribution of the LINC complex (for Linker of Nucleoskeleton to Cytoskeleton), hosting KASH and SUN proteins interactions. This close interplay between compartments has been related to diverse functions from nuclear integrity, activity and positioning through mechanotransduction pathways. At the same time, mutations in NE components genes coding for proteins such as lamins or nesprins, had been associated with a wide range of congenital diseases including cardiac and muscular diseases. Although most of these NE associated proteins are ubiquitously expressed, a large number of tissue-specific disorders have been associated with diverse pathogenic mutations. Thus, diagnosis and molecular explanation of this group of diseases, commonly called “nuclear envelopathies,” is currently challenging. This review aims, first, to give a better understanding of diverse functions of the LINC complex components, from the point of view of lamins and nesprins. Second, to summarize human congenital diseases with a special focus on muscle and heart abnormalities, caused by mutations in genes coding for these two types of NE associated proteins.
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Affiliation(s)
- Alexandre Janin
- CNRS UMR5310, INSERM U1217, Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.,Laboratoire de Cardiogénétique Moléculaire, Centre de Biologie et Pathologie Est, Hospices Civils de Lyon, Bron, France
| | - Vincent Gache
- CNRS UMR5310, INSERM U1217, Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
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42
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Jahed Z, Vu UT, Fadavi D, Ke H, Rathish A, Kim SCJ, Feng W, Mofrad MRK. A molecular model for LINC complex regulation: activation of SUN2 for KASH binding. Mol Biol Cell 2018; 29:2012-2023. [PMID: 29995584 PMCID: PMC6232973 DOI: 10.1091/mbc.e18-04-0266] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Linkers of the nucleoskeleton and cytoskeleton are key molecular complexes that span the nuclear envelope (NE) and provide a direct linkage between the nucleoskeleton and cytoskeleton. Two major components of these complexes are members of the SUN and KASH protein families that interact in the perinuclear space to allow the transmission of mechanochemical signals across the NE. Structural details of the mammalian SUN domain protein SUN2 have established that SUN2 must form a trimer to bind to KASH, and that this trimerization is mediated through two predicted coiled-coil regions of the protein, CC1 and CC2, which precede the SUN domain. Recent crystallographic data suggest that CC2-SUN formed an unexpected autoinhibited monomer unable to bind to KASH. These structural insights raise the question of how full-length SUN2 transitions from a monomer to a trimer inside the NE. In this study we used a computational approach to model a fragment of SUN2 containing CC1, CC2, and the SUN domain. We observed the dynamics of these modeled structures using ∼1 μs molecular dynamics simulations and showed that the interplay between CC1 and CC2 may be sufficient for the release of CC2-SUN2 from its autoinhibited state. Additionally, using our models and gel filtration analysis, we show the involvement of an E452 residue on CC1 in the monomer–trimer transition of SUN2. Intriguingly, mutations in this residue have been seen in muscular dystrophy–associated SUN2 variants. Finally, we propose a Ca2+-dependent monomer–trimer transition of SUN2.
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Affiliation(s)
- Zeinab Jahed
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Uyen T Vu
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Darya Fadavi
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Huimin Ke
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Akshay Rathish
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Samuel C J Kim
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Wei Feng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Mohammad R K Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720.,Molecular Biophysics and Integrative Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
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43
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Mouse models of nesprin-related diseases. Biochem Soc Trans 2018; 46:669-681. [PMID: 29784648 DOI: 10.1042/bst20180085] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/05/2018] [Accepted: 04/20/2018] [Indexed: 02/05/2023]
Abstract
Nesprins (nuclear envelope spectrin repeat proteins) are a family of multi-isomeric scaffolding proteins. Nesprins form the LInker of Nucleoskeleton-and-Cytoskeleton (LINC) complex with SUN (Sad1p/UNC84) domain-containing proteins at the nuclear envelope, in association with lamin A/C and emerin, linking the nucleoskeleton to the cytoskeleton. The LINC complex serves as both a physical linker between the nuclear lamina and the cytoskeleton and a mechanosensor. The LINC complex has a broad range of functions and is involved in maintaining nuclear architecture, nuclear positioning and migration, and also modulating gene expression. Over 80 disease-related variants have been identified in SYNE-1/2 (nesprin-1/2) genes, which result in muscular or central nervous system disorders including autosomal dominant Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy and autosomal recessive cerebellar ataxia type 1. To date, 17 different nesprin mouse lines have been established to mimic these nesprin-related human diseases, which have provided valuable insights into the roles of nesprin and its scaffold LINC complex in a tissue-specific manner. In this review, we summarise the existing nesprin mouse models, compare their phenotypes and discuss the potential mechanisms underlying nesprin-associated diseases.
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44
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Tan KL, Haelterman NA, Kwartler CS, Regalado ES, Lee PT, Nagarkar-Jaiswal S, Guo DC, Duraine L, Wangler MF, Bamshad MJ, Nickerson DA, Lin G, Milewicz DM, Bellen HJ. Ari-1 Regulates Myonuclear Organization Together with Parkin and Is Associated with Aortic Aneurysms. Dev Cell 2018; 45:226-244.e8. [PMID: 29689197 PMCID: PMC5920516 DOI: 10.1016/j.devcel.2018.03.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 02/15/2018] [Accepted: 03/26/2018] [Indexed: 12/25/2022]
Abstract
Nuclei are actively positioned and anchored to the cytoskeleton via the LINC (Linker of Nucleoskeleton and Cytoskeleton) complex. We identified mutations in the Parkin-like E3 ubiquitin ligase Ariadne-1 (Ari-1) that affect the localization and distribution of LINC complex members in Drosophila. ari-1 mutants exhibit nuclear clustering and morphology defects in larval muscles. We show that Ari-1 mono-ubiquitinates the core LINC complex member Koi. Surprisingly, we discovered functional redundancy between Parkin and Ari-1: increasing Parkin expression rescues ari-1 mutant phenotypes and vice versa. We further show that rare variants in the human homolog of ari-1 (ARIH1) are associated with thoracic aortic aneurysms and dissections, conditions resulting from smooth muscle cell (SMC) dysfunction. Human ARIH1 rescues fly ari-1 mutant phenotypes, whereas human variants found in patients fail to do so. In addition, SMCs obtained from patients display aberrant nuclear morphology. Hence, ARIH1 is critical in anchoring myonuclei to the cytoskeleton.
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Affiliation(s)
- Kai Li Tan
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX 77030, USA
| | - Nele A Haelterman
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Callie S Kwartler
- Department of Internal Medicine, The University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX 77030, USA
| | - Ellen S Regalado
- Department of Internal Medicine, The University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX 77030, USA
| | - Pei-Tseng Lee
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Sonal Nagarkar-Jaiswal
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Howard Hughes Medical Institute, BCM, Houston, TX 77030, USA
| | - Dong-Chuan Guo
- Department of Internal Medicine, The University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX 77030, USA
| | - Lita Duraine
- Howard Hughes Medical Institute, BCM, Houston, TX 77030, USA
| | - Michael F Wangler
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Michael J Bamshad
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Deborah A Nickerson
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Guang Lin
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Dianna M Milewicz
- Department of Internal Medicine, The University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX 77030, USA
| | - Hugo J Bellen
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Howard Hughes Medical Institute, BCM, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA; Department of Neuroscience, BCM, Houston, TX 77030, USA.
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45
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Nesprin-1/2: roles in nuclear envelope organisation, myogenesis and muscle disease. Biochem Soc Trans 2018; 46:311-320. [PMID: 29487227 DOI: 10.1042/bst20170149] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/12/2018] [Accepted: 01/17/2018] [Indexed: 02/05/2023]
Abstract
Nesprins (nuclear envelope spectrin repeat proteins) are multi-isomeric scaffolding proteins. Nesprin-1 and -2 are highly expressed in skeletal and cardiac muscles and together with SUN (Sad1p/UNC84) domain-containing proteins form the LInker of Nucleoskeleton and Cytoskeleton (LINC) complex at the nuclear envelope in association with lamin A/C and emerin. Mutations in nesprin-1/2 have been found in patients with autosomal dominant Emery-Dreifuss muscular dystrophy (EDMD) as well as dilated cardiomyopathy (DCM). Several lines of evidence indicate that compromised LINC complex function is the critical step leading to muscle disease. Here, we review recent advances in our understanding of the functions of nesprin-1/2 in the LINC complex and mechanistic insights into how mutations in nesprin-1/2 lead to nesprin-related muscle diseases, in particular DCM and EDMD.
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46
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Emerging views of the nucleus as a cellular mechanosensor. Nat Cell Biol 2018; 20:373-381. [PMID: 29467443 DOI: 10.1038/s41556-018-0038-y] [Citation(s) in RCA: 333] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/09/2018] [Indexed: 12/14/2022]
Abstract
The ability of cells to respond to mechanical forces is critical for numerous biological processes. Emerging evidence indicates that external mechanical forces trigger changes in nuclear envelope structure and composition, chromatin organization and gene expression. However, it remains unclear if these processes originate in the nucleus or are downstream of cytoplasmic signals. Here we discuss recent findings that support a direct role of the nucleus in cellular mechanosensing and highlight novel tools to study nuclear mechanotransduction.
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47
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Next-Generation Sequencing and Mutational Analysis: Implications for Genes Encoding LINC Complex Proteins. Methods Mol Biol 2018; 1840:321-336. [PMID: 30141054 DOI: 10.1007/978-1-4939-8691-0_22] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Targeted panel, whole exome, or whole genome DNA sequencing using next-generation sequencing (NGS) allows for extensive high-throughput investigation of molecular machines/systems such as the LINC complex. This includes the identification of genetic variants in humans that cause disease, as is the case for some genes encoding LINC complex proteins. The relatively low cost and high speed of the sequencing process results in large datasets at various stages of analysis and interpretation. For those not intimately familiar with the process, interpretation of the data might prove challenging. This review lays out the most important and most commonly used materials and methods of NGS. It also discusses data analysis and potential pitfalls one might encounter because of peculiarities of the laboratory methodology or data analysis pipelines.
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48
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Zhu R, Antoku S, Gundersen GG. Centrifugal Displacement of Nuclei Reveals Multiple LINC Complex Mechanisms for Homeostatic Nuclear Positioning. Curr Biol 2017; 27:3097-3110.e5. [PMID: 28988861 DOI: 10.1016/j.cub.2017.08.073] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/26/2017] [Accepted: 08/30/2017] [Indexed: 11/18/2022]
Abstract
Nuclear movement is critical for developmental events, cell polarity, and migration and is usually mediated by linker of nucleoskeleton and cytoskeleton (LINC) complexes connecting the nucleus to cytoskeletal elements. Compared to active nuclear movement, relatively little is known about homeostatic positioning of nuclei, including whether it is an active process. To explore homeostatic nuclear positioning, we developed a method to displace nuclei in adherent cells using centrifugal force. Nuclei displaced by centrifugation rapidly recentered by mechanisms that depended on cell context. In cell monolayers with wounds oriented orthogonal to the force, nuclei were displaced toward the front and back of the cells on the two sides of the wound. Nuclei recentered from both positions, but at different rates and with different cytoskeletal linkage mechanisms. Rearward recentering was actomyosin, nesprin-2G, and SUN2 dependent, whereas forward recentering was microtubule, dynein, nesprin-2G, and SUN1 dependent. Nesprin-2G engaged actin through its N terminus and microtubules through a novel dynein interacting site near its C terminus. Both activities were necessary to maintain nuclear position in uncentrifuged cells. Thus, even when not moving, nuclei are actively maintained in position by engaging the cytoskeleton through the LINC complex.
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Affiliation(s)
- Ruijun Zhu
- Department of Pathology and Cell Biology, Columbia University, 630 West 168(th) Street, New York, NY 10032, USA
| | - Susumu Antoku
- Department of Pathology and Cell Biology, Columbia University, 630 West 168(th) Street, New York, NY 10032, USA
| | - Gregg G Gundersen
- Department of Pathology and Cell Biology, Columbia University, 630 West 168(th) Street, New York, NY 10032, USA.
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49
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Rapisarda V, Malashchuk I, Asamaowei IE, Poterlowicz K, Fessing MY, Sharov AA, Karakesisoglou I, Botchkarev VA, Mardaryev A. p63 Transcription Factor Regulates Nuclear Shape and Expression of Nuclear Envelope-Associated Genes in Epidermal Keratinocytes. J Invest Dermatol 2017; 137:2157-2167. [PMID: 28595999 PMCID: PMC5610935 DOI: 10.1016/j.jid.2017.05.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/20/2017] [Accepted: 05/01/2017] [Indexed: 01/07/2023]
Abstract
The maintenance of a proper nuclear architecture and three-dimensional organization of the genes, enhancer elements, and transcription machinery plays an essential role in tissue development and regeneration. Here we show that in the developing skin, epidermal progenitor cells of mice lacking p63 transcription factor display alterations in the nuclear shape accompanied by a marked decrease in expression of several nuclear envelope-associated components (Lamin B1, Lamin A/C, Sun1, Nesprin-3, Plectin) compared with controls. Furthermore, chromatin immunoprecipitation-quantitative PCR assay showed enrichment of p63 on Sun1, Syne3, and Plec promoters, suggesting them as p63 targets. Alterations in the nuclei shape and expression of nuclear envelope-associated proteins were accompanied by altered distribution patterns of the repressive histone marks trimethylation on lysine 27 of histone H3, trimethylation on lysine 9 of histone H3, and heterochromatin protein 1-alpha in p63-null keratinocytes. These changes were also accompanied by downregulation of the transcriptional activity and relocation of the keratinocyte-specific gene loci away from the sites of active transcription toward the heterochromatin-enriched repressive nuclear compartments in p63-null cells. These data demonstrate functional links between the nuclear envelope organization, chromatin architecture, and gene expression in keratinocytes and suggest nuclear envelope-associated genes as important targets mediating p63-regulated gene expression program in the epidermis.
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Key Words
- cc, chromocenter
- chip-qpcr, chromatin immunoprecipitation-quantitative pcr
- h3k9me3, trimethylation on lysine 9 of histone h3
- h3k27me3, trimethylation on lysine 27 of histone h3
- ktyi, keratin type i
- ktyii, keratin type ii
- pmk, primary mouse keratinocyte
- if, intermediate filament
- nm, nuclear membrane
- ne, nuclear envelope
- wt, wild-type
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Affiliation(s)
| | - Igor Malashchuk
- Centre for Skin Sciences, University of Bradford, Bradford, UK
| | | | | | | | - Andrey A Sharov
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA
| | | | - Vladimir A Botchkarev
- Centre for Skin Sciences, University of Bradford, Bradford, UK; Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA.
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50
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Roman W, Martins JP, Carvalho FA, Voituriez R, Abella JV, Santos NC, Cadot B, Way M, Gomes ER. Myofibril contraction and crosslinking drive nuclear movement to the periphery of skeletal muscle. Nat Cell Biol 2017; 19:1189-1201. [PMID: 28892082 PMCID: PMC5675053 DOI: 10.1038/ncb3605] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/04/2017] [Indexed: 12/17/2022]
Abstract
Nuclear movements are important for multiple cellular functions, and are driven by polarized forces generated by motor proteins and the cytoskeleton. During skeletal myofibre formation or regeneration, nuclei move from the centre to the periphery of the myofibre for proper muscle function. Centrally located nuclei are also found in different muscle disorders. Using theoretical and experimental approaches, we demonstrate that nuclear movement to the periphery of myofibres is mediated by centripetal forces around the nucleus. These forces arise from myofibril contraction and crosslinking that 'zip' around the nucleus in combination with tight regulation of nuclear stiffness by lamin A/C. In addition, an Arp2/3 complex containing Arpc5L together with γ-actin is required to organize desmin to crosslink myofibrils for nuclear movement. Our work reveals that centripetal forces exerted by myofibrils squeeze the nucleus to the periphery of myofibres.
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Affiliation(s)
- William Roman
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, GH Pitié-Salpêtrière, 47 Boulevard de l'hôpital, 75013 Paris, France; Centre de Référence de Pathologie Neuromusculaire Paris-Est, Institut de Myologie, GHU La Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisboa, Portugal
| | - Joao P. Martins
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisboa, Portugal
| | - Filomena A. Carvalho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisboa, Portugal
| | - Raphael Voituriez
- Laboratoire de Physique Théorique de la Matière Condensée; CNRS UMR 7600; Université Pierre et Marie Curie, Paris , France
- Laboratoire Jean Perrin; CNRS FRE 3231, Université Pierre et Marie Curie ; Paris, France
| | - Jasmine V.G. Abella
- Cellular Signalling and Cytoskeletal Function, The Francis Crick Institute, 44 Lincoln’s Inn Fields, London, WC2A 3LY, UK
| | - Nuno C. Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisboa, Portugal
| | - Bruno Cadot
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, GH Pitié-Salpêtrière, 47 Boulevard de l'hôpital, 75013 Paris, France; Centre de Référence de Pathologie Neuromusculaire Paris-Est, Institut de Myologie, GHU La Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Michael Way
- Cellular Signalling and Cytoskeletal Function, The Francis Crick Institute, 44 Lincoln’s Inn Fields, London, WC2A 3LY, UK
| | - Edgar R. Gomes
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, GH Pitié-Salpêtrière, 47 Boulevard de l'hôpital, 75013 Paris, France; Centre de Référence de Pathologie Neuromusculaire Paris-Est, Institut de Myologie, GHU La Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisboa, Portugal
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