1
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Fleming JR, Müller I, Zacharchenko T, Diederichs K, Mayans O. Molecular insights into titin's A-band. J Muscle Res Cell Motil 2023; 44:255-270. [PMID: 37258982 PMCID: PMC10665226 DOI: 10.1007/s10974-023-09649-1] [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: 03/06/2023] [Accepted: 04/11/2023] [Indexed: 06/02/2023]
Abstract
The thick filament-associated A-band region of titin is a highly repetitive component of the titin chain with important scaffolding properties that support thick filament assembly. It also has a demonstrated link to human disease. Despite its functional significance, it remains a largely uncharacterized part of the titin protein. Here, we have performed an analysis of sequence and structure conservation of A-band titin, with emphasis on poly-FnIII tandem components. Specifically, we have applied multi-dimensional sequence pairwise similarity analysis to FnIII domains and complemented this with the crystallographic elucidation of the 3D-structure of the FnIII-triplet A84-A86 from the fourth long super-repeat in the C-zone (C4). Structural models serve here as templates to map sequence conservation onto super-repeat C4, which we show is a prototypical representative of titin's C-zone. This templating identifies positionally conserved residue clusters in C super-repeats with the potential of mediating interactions to thick-filament components. Conservation localizes to two super-repeat positions: Ig domains in position 1 and FnIII domains in position 7. The analysis also allows conclusions to be drawn on the conserved architecture of titin's A-band, as well as revisiting and expanding the evolutionary model of titin's A-band.
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Affiliation(s)
| | - Iljas Müller
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Thomas Zacharchenko
- Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
- Wellcome Centre for Cell-Matrix Research, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Kay Diederichs
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Olga Mayans
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany.
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2
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Di Feo MF, Lillback V, Jokela M, McEntagart M, Homfray T, Giorgio E, Casalis Cavalchini GC, Brusco A, Iascone M, Spaccini L, D'Oria P, Savarese M, Udd B. The crucial role of titin in fetal development: recurrent miscarriages and bone, heart and muscle anomalies characterise the severe end of titinopathies spectrum. J Med Genet 2023; 60:866-873. [PMID: 36977548 DOI: 10.1136/jmg-2022-109018] [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: 10/31/2022] [Accepted: 01/18/2023] [Indexed: 03/30/2023]
Abstract
BACKGROUND Titin truncating variants (TTNtvs) have been associated with several forms of myopathies and/or cardiomyopathies. In homozygosity or in compound heterozygosity, they cause a wide spectrum of recessive phenotypes with a congenital or childhood onset. Most recessive phenotypes showing a congenital or childhood onset have been described in subjects carrying biallelic TTNtv in specific exons. Often karyotype or chromosomal microarray analyses are the only tests performed when prenatal anomalies are identified. Thereby, many cases caused by TTN defects might be missed in the diagnostic evaluations. In this study, we aimed to dissect the most severe end of the titinopathies spectrum. METHODS We performed a retrospective study analysing an international cohort of 93 published and 10 unpublished cases carrying biallelic TTNtv. RESULTS We identified recurrent clinical features showing a significant correlation with the genotype, including fetal akinesia (up to 62%), arthrogryposis (up to 85%), facial dysmorphisms (up to 73%), joint (up to 17%), bone (up to 22%) and heart anomalies (up to 27%) resembling complex, syndromic phenotypes. CONCLUSION We suggest TTN to be carefully evaluated in any diagnostic process involving patients with these prenatal signs. This step will be essential to improve diagnostic performance, expand our knowledge and optimise prenatal genetic counselling.
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Affiliation(s)
- Maria Francesca Di Feo
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health (DINOGMI), University of Genoa, Genova, Italy
| | - Victoria Lillback
- Folkhälsan Research Center, Helsinki, Uusimaa, Finland
- University of Helsinki Department of Medical and Clinical Genetics, Helsinki, Uusimaa, Finland
| | - Manu Jokela
- Tampere University Hospital, Tampere, Pirkanmaa, Finland
- TYKS Turku University Hospital, Turku, Varsinais-Suomi, Finland
| | - Meriel McEntagart
- Department of Medical Genetics, St George's University of London, London, London, UK
| | - Tessa Homfray
- St George's University of London, London, London, UK
| | - Elisa Giorgio
- Department of Molecular Medicine, University of Pavia, Pavia, Lombardia, Italy
- Fondazione Istituto Neurologico Nazionale C Mondino Istituto di Ricovero e Cura a Carattere Scientifico, Pavia, Lombardia, Italy
| | - Guido C Casalis Cavalchini
- Medical Genetics Unit, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Piemonte, Italy
| | - Alfredo Brusco
- Department of Medical Sciences, University of Turin School of Medicine, Torino, Piemonte, Italy
| | - Maria Iascone
- Laboratorio di Genetica Medica, ASST Papa Giovanni XXIII, Bergamo, BG, Italy
| | - Luigina Spaccini
- Unità di Genetica Medica, UOC Ostetricia e Ginecologia, Ospedale dei Bambini Vittore Buzzi, Milano, Lombardia, Italy
| | - Patrizia D'Oria
- UOC Ostetrica e Ginecologia, Ospedale Bolognini di Seriate, Seriate, Lombardia, Italy
| | - Marco Savarese
- Folkhälsan Research Center, Helsinki, Uusimaa, Finland
- Department of Medical Genetics, University of Helsinki, Helsinki, Uusimaa, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Uusimaa, Finland
- Tampere University Hospital Department of Musculoskeletal Diseases, Tampere, Pirkanmaa, Finland
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3
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Taylor KA. John Squire and the myosin thick filament structure in muscle. J Muscle Res Cell Motil 2023; 44:143-152. [PMID: 37099254 PMCID: PMC10686309 DOI: 10.1007/s10974-023-09646-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/22/2023] [Indexed: 04/27/2023]
Abstract
The structure of the thin, actin-containing filament of muscle is both highly conserved across a broad range of muscle types and is now well understood. The structure of the thick, myosin-containing filaments of striated muscle are quite variable and remained comparatively unknown until recently, particularly in the arrangement of the myosin tails. John Squire played a major role not only in our understanding of thin filament structure and function but also in the structure of the thick filaments. Long before much was known about the structure and composition of muscle thick filaments, he proposed a general model for how myosin filaments were constructed. His role in our current understanding the structure of striated muscle thick filaments and the extent through which his predictions have held true is the topic of this review.
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Affiliation(s)
- Kenneth A Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306-4380, USA.
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4
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González Morales N, Marescal O, Szikora S, Katzemich A, Correia-Mesquita T, Bíró P, Erdelyi M, Mihály J, Schöck F. The oxoglutarate dehydrogenase complex is involved in myofibril growth and Z-disc assembly in Drosophila. J Cell Sci 2023; 136:jcs260717. [PMID: 37272588 PMCID: PMC10323237 DOI: 10.1242/jcs.260717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 05/24/2023] [Indexed: 06/06/2023] Open
Abstract
Myofibrils are long intracellular cables specific to muscles, composed mainly of actin and myosin filaments. The actin and myosin filaments are organized into repeated units called sarcomeres, which form the myofibrils. Muscle contraction is achieved by the simultaneous shortening of sarcomeres, which requires all sarcomeres to be the same size. Muscles have a variety of ways to ensure sarcomere homogeneity. We have previously shown that the controlled oligomerization of Zasp proteins sets the diameter of the myofibril. Here, we looked for Zasp-binding proteins at the Z-disc to identify additional proteins coordinating myofibril growth and assembly. We found that the E1 subunit of the oxoglutarate dehydrogenase complex localizes to both the Z-disc and the mitochondria, and is recruited to the Z-disc by Zasp52. The three subunits of the oxoglutarate dehydrogenase complex are required for myofibril formation. Using super-resolution microscopy, we revealed the overall organization of the complex at the Z-disc. Metabolomics identified an amino acid imbalance affecting protein synthesis as a possible cause of myofibril defects, which is supported by OGDH-dependent localization of ribosomes at the Z-disc.
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Affiliation(s)
- Nicanor González Morales
- Department of Biology, McGill University, Quebec H3A 1B1, Canada
- Department of Biology, Dalhousie University, Nova Scotia B3H 4R2, Canada
| | - Océane Marescal
- Department of Biology, McGill University, Quebec H3A 1B1, Canada
| | - Szilárd Szikora
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged 6726, Hungary
| | - Anja Katzemich
- Department of Biology, McGill University, Quebec H3A 1B1, Canada
| | | | - Péter Bíró
- Department of Optics and Quantum Electronics, University of Szeged, Szeged 6720, Hungary
| | - Miklos Erdelyi
- Department of Optics and Quantum Electronics, University of Szeged, Szeged 6720, Hungary
| | - József Mihály
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged 6726, Hungary
- Department of Genetics, University of Szeged, Szeged 6726, Hungary
| | - Frieder Schöck
- Department of Biology, McGill University, Quebec H3A 1B1, Canada
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5
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Parker F, Tang AAS, Rogers B, Carrington G, dos Remedios C, Li A, Tomlinson D, Peckham M. Affimers targeting proteins in the cardiomyocyte Z-disc: Novel tools that improve imaging of heart tissue. Front Cardiovasc Med 2023; 10:1094563. [PMID: 36865889 PMCID: PMC9971620 DOI: 10.3389/fcvm.2023.1094563] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/30/2023] [Indexed: 02/16/2023] Open
Abstract
Dilated Cardiomyopathy is a common form of heart failure. Determining how this disease affects the structure and organization of cardiomyocytes in the human heart is important in understanding how the heart becomes less effective at contraction. Here we isolated and characterised Affimers (small non-antibody binding proteins) to Z-disc proteins ACTN2 (α-actinin-2), ZASP (also known as LIM domain binding protein 3 or LDB3) and the N-terminal region of the giant protein titin (TTN Z1-Z2). These proteins are known to localise in both the sarcomere Z-discs and the transitional junctions, found close to the intercalated discs that connect adjacent cardiomyocytes. We use cryosections of left ventricles from two patients diagnosed with end-stage Dilated Cardiomyopathy who underwent Orthotopic Heart Transplantation and were whole genome sequenced. We describe how Affimers substantially improve the resolution achieved by confocal and STED microscopy compared to conventional antibodies. We quantified the expression of ACTN2, ZASP and TTN proteins in two patients with dilated cardiomyopathy and compared them with a sex- and age-matched healthy donor. The small size of the Affimer reagents, combined with a small linkage error (the distance from the epitope to the dye label covalently bound to the Affimer) revealed new structural details in Z-discs and intercalated discs in the failing samples. Affimers are thus useful for analysis of changes to cardiomyocyte structure and organisation in diseased hearts.
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Affiliation(s)
- Francine Parker
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Anna A. S. Tang
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Brendan Rogers
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Glenn Carrington
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Cris dos Remedios
- Mechanobiology Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
| | - Amy Li
- Sydney Heart Bank, The University of Sydney, Sydney, NSW, Australia
- Department of Pharmacy & Biomedical Sciences, La Trobe University, Bendigo, VIC, Australia
- Centre for Healthy Futures, Torrens University Australia, Surrey Hills, NSW, Australia
| | - Darren Tomlinson
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Michelle Peckham
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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6
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Schueder F, Mangeol P, Chan EH, Rees R, Schünemann J, Jungmann R, Görlich D, Schnorrer F. Nanobodies combined with DNA-PAINT super-resolution reveal a staggered titin nanoarchitecture in flight muscles. eLife 2023; 12:79344. [PMID: 36645127 PMCID: PMC9886278 DOI: 10.7554/elife.79344] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 11/22/2022] [Indexed: 01/17/2023] Open
Abstract
Sarcomeres are the force-producing units of all striated muscles. Their nanoarchitecture critically depends on the large titin protein, which in vertebrates spans from the sarcomeric Z-disc to the M-band and hence links actin and myosin filaments stably together. This ensures sarcomeric integrity and determines the length of vertebrate sarcomeres. However, the instructive role of titins for sarcomeric architecture outside of vertebrates is not as well understood. Here, we used a series of nanobodies, the Drosophila titin nanobody toolbox, recognising specific domains of the two Drosophila titin homologs Sallimus and Projectin to determine their precise location in intact flight muscles. By combining nanobodies with DNA-PAINT super-resolution microscopy, we found that, similar to vertebrate titin, Sallimus bridges across the flight muscle I-band, whereas Projectin is located at the beginning of the A-band. Interestingly, the ends of both proteins overlap at the I-band/A-band border, revealing a staggered organisation of the two Drosophila titin homologs. This architecture may help to stably anchor Sallimus at the myosin filament and hence ensure efficient force transduction during flight.
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Affiliation(s)
- Florian Schueder
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian UniversityMunichGermany
- Max Planck Institute of BiochemistryMartinsriedGermany
| | - Pierre Mangeol
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living SystemsMarseilleFrance
| | - Eunice HoYee Chan
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living SystemsMarseilleFrance
| | - Renate Rees
- Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | | | - Ralf Jungmann
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian UniversityMunichGermany
- Max Planck Institute of BiochemistryMartinsriedGermany
| | - Dirk Görlich
- Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Frank Schnorrer
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living SystemsMarseilleFrance
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7
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Schöck F, González-Morales N. The insect perspective on Z-disc structure and biology. J Cell Sci 2022; 135:277280. [PMID: 36226637 DOI: 10.1242/jcs.260179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myofibrils are the intracellular structures formed by actin and myosin filaments. They are paracrystalline contractile cables with unusually well-defined dimensions. The sliding of actin past myosin filaments powers contractions, and the entire system is held in place by a structure called the Z-disc, which anchors the actin filaments. Myosin filaments, in turn, are anchored to another structure called the M-line. Most of the complex architecture of myofibrils can be reduced to studying the Z-disc, and recently, important advances regarding the arrangement and function of Z-discs in insects have been published. On a very small scale, we have detailed protein structure information. At the medium scale, we have cryo-electron microscopy maps, super-resolution microscopy and protein-protein interaction networks, while at the functional scale, phenotypic data are available from precise genetic manipulations. All these data aim to answer how the Z-disc works and how it is assembled. Here, we summarize recent data from insects and explore how it fits into our view of the Z-disc, myofibrils and, ultimately, muscles.
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Affiliation(s)
- Frieder Schöck
- Department of Biology, McGill University, Montreal, Quebec, H3A 1B1, Canada
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8
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Tolkatchev D, Gregorio CC, Kostyukova AS. The role of leiomodin in actin dynamics: a new road or a secret gate. FEBS J 2022; 289:6119-6131. [PMID: 34273242 PMCID: PMC8761783 DOI: 10.1111/febs.16128] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/10/2021] [Accepted: 07/16/2021] [Indexed: 12/29/2022]
Abstract
Leiomodin is an important emerging regulator of thin filaments. As novel molecular, cellular, animal model, and human data accumulate, the mechanisms of its action become clearer. Structural studies played a significant part in understanding the functional significance of leiomodin's interacting partners and functional domains. In this review, we present the current state of knowledge on the structural and cellular properties of leiomodin which has led to two proposed mechanisms of its function. Although it is known that leiomodin is essential for life, numerous domains within leiomodin remain unstudied and as such, we outline future directions for investigations that we predict will provide evidence that leiomodin is a multifunctional protein.
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Affiliation(s)
- Dmitri Tolkatchev
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164, USA
| | - Carol C. Gregorio
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ 85724, USA
| | - Alla S. Kostyukova
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164, USA
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9
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Sagath L, Lehtokari VL, Wallgren-Pettersson C, Pelin K, Kiiski K. A custom ddPCR method for the detection of copy number variations in the nebulin triplicate region. PLoS One 2022; 17:e0267793. [PMID: 35576196 PMCID: PMC9109913 DOI: 10.1371/journal.pone.0267793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 04/15/2022] [Indexed: 11/21/2022] Open
Abstract
The human genome contains repetitive regions, such as segmental duplications, known to be prone to copy number variation. Segmental duplications are highly identical and homologous sequences, posing a specific challenge for most mutation detection methods. The giant nebulin gene is expressed in skeletal muscle. It harbors a large segmental duplication region composed of eight exons repeated three times, the so-called triplicate region. Mutations in nebulin are known to cause nemaline myopathy and other congenital myopathies. Using our custom targeted Comparative Genomic Hybridization arrays, we have previously shown that copy number variations in the nebulin triplicate region are pathogenic when the copy number of the segmental duplication block deviates two or more copies from the normal number, which is three per allele. To complement our Comparative Genomic Hybridization arrays, we have established a custom Droplet Digital PCR method for the detection of copy number variations within the nebulin triplicate region. The custom Droplet Digital PCR assays allow sensitive, rapid, high-throughput, and cost-effective detection of copy number variations within this region and is ready for implementation a screening method for disease-causing copy number variations of the nebulin triplicate region. We suggest that Droplet Digital PCR may also be used in the study and diagnostics of other segmental duplication regions of the genome.
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Affiliation(s)
- Lydia Sagath
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- * E-mail: , (LS); (KK)
| | - Vilma-Lotta Lehtokari
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Carina Wallgren-Pettersson
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Katarina Pelin
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Kirsi Kiiski
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- * E-mail: , (LS); (KK)
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10
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Szikora S, Görög P, Mihály J. The Mechanisms of Thin Filament Assembly and Length Regulation in Muscles. Int J Mol Sci 2022; 23:5306. [PMID: 35628117 PMCID: PMC9140763 DOI: 10.3390/ijms23105306] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 02/01/2023] Open
Abstract
The actin containing tropomyosin and troponin decorated thin filaments form one of the crucial components of the contractile apparatus in muscles. The thin filaments are organized into densely packed lattices interdigitated with myosin-based thick filaments. The crossbridge interactions between these myofilaments drive muscle contraction, and the degree of myofilament overlap is a key factor of contractile force determination. As such, the optimal length of the thin filaments is critical for efficient activity, therefore, this parameter is precisely controlled according to the workload of a given muscle. Thin filament length is thought to be regulated by two major, but only partially understood mechanisms: it is set by (i) factors that mediate the assembly of filaments from monomers and catalyze their elongation, and (ii) by factors that specify their length and uniformity. Mutations affecting these factors can alter the length of thin filaments, and in human cases, many of them are linked to debilitating diseases such as nemaline myopathy and dilated cardiomyopathy.
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Affiliation(s)
- Szilárd Szikora
- Institute of Genetics, Biological Research Centre, H-6726 Szeged, Hungary;
| | - Péter Görög
- Institute of Genetics, Biological Research Centre, H-6726 Szeged, Hungary;
- Doctoral School of Multidisciplinary Medical Science, Faculty of Medicine, University of Szeged, H-6725 Szeged, Hungary
| | - József Mihály
- Institute of Genetics, Biological Research Centre, H-6726 Szeged, Hungary;
- Department of Genetics, University of Szeged, H-6726 Szeged, Hungary
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11
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Nanosurgical Manipulation of Titin and Its M-Complex. NANOMATERIALS 2022; 12:nano12020178. [PMID: 35055197 PMCID: PMC8779236 DOI: 10.3390/nano12020178] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/01/2022] [Accepted: 01/04/2022] [Indexed: 01/21/2023]
Abstract
Titin is a multifunctional filamentous protein anchored in the M-band, a hexagonally organized supramolecular lattice in the middle of the muscle sarcomere. Functionally, the M-band is a framework that cross-links myosin thick filaments, organizes associated proteins, and maintains sarcomeric symmetry via its structural and putative mechanical properties. Part of the M-band appears at the C-terminal end of isolated titin molecules in the form of a globular head, named here the “M-complex”, which also serves as the point of head-to-head attachment of titin. We used high-resolution atomic force microscopy and nanosurgical manipulation to investigate the topographical and internal structure and local mechanical properties of the M-complex and its associated titin molecules. We find that the M-complex is a stable structure that corresponds to the transverse unit of the M-band organized around the myosin thick filament. M-complexes may be interlinked into an M-complex array that reflects the local structural and mechanical status of the transversal M-band lattice. Local segments of titin and the M-complex could be nanosurgically manipulated to achieve extension and domain unfolding. Long threads could be pulled out of the M-complex, suggesting that it is a compact supramolecular reservoir of extensible filaments. Nanosurgery evoked an unexpected volume increment in the M-complex, which may be related to its function as a mechanical spacer. The M-complex thus displays both elastic and plastic properties which support the idea that the M-band may be involved in mechanical functions within the muscle sarcomere.
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12
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Liu R, Wu GY, Li KY, Ge QF, Wu MG, Yu H, Wu SL, Bao WB. Comparative Study on Pale, Soft and Exudative (PSE) and Red, Firm and Non-Exudative (RFN) Pork: Protein Changes during Aging and the Differential Protein Expression of the Myofibrillar Fraction at 1 h Postmortem. Foods 2021; 10:foods10040733. [PMID: 33808327 PMCID: PMC8066169 DOI: 10.3390/foods10040733] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 01/06/2023] Open
Abstract
In this paper, the protein changes during aging and the differences in the myofibrillar protein fraction at 1 h postmortem of pale, soft and exudative (PSE), and red, firm and non-exudative (RFN) pork longissimus thoracis (LT) were comparatively studied. The PSE and RFN groups were screened out based on the differences in their pH and lightness (L*) at 1 h, and their purge loss at 24 h postmortem. Based on the measured MFI, desmin degradation, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, PSE meat presented more significant changes in the myofibrillar protein fraction compared to RFN meat during postmortem aging. Through liquid chromatograph-mass spectrometer/mass spectrometer (LC-MS/MS) analysis, a total of 172 differential proteins were identified, among which 151 were up-regulated and 21 were down-regulated in the PSE group. The differential proteins were muscle contraction, motor proteins, microfilaments, microtubules, glycolysis, glycogen metabolism, energy metabolism, molecular chaperones, transport, and enzyme proteins. The AMP activated protein kinase (AMPK) signaling pathway, HIF-1 signaling pathway, calcium signaling pathway, and PI3K-Akt signaling pathway were identified as the significant pathways related to meat quality. This study suggested that the different changes of the myofibrillar protein fraction were involved in the biochemical metabolism in postmortem muscle, which may contribute to the molecular understanding of PSE meat formation.
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Affiliation(s)
- Rui Liu
- Industrial Engineering Center for Huaiyang Cuisine of Jiangsu Province, College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China; (R.L.); (G.-Y.W.); (K.-Y.L.); (M.-G.W.); (H.Y.)
- Jiangsu Key Laboratory of Animal Genetic Breeding and Molecular Design, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China;
| | - Guo-Yue Wu
- Industrial Engineering Center for Huaiyang Cuisine of Jiangsu Province, College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China; (R.L.); (G.-Y.W.); (K.-Y.L.); (M.-G.W.); (H.Y.)
| | - Ke-Yue Li
- Industrial Engineering Center for Huaiyang Cuisine of Jiangsu Province, College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China; (R.L.); (G.-Y.W.); (K.-Y.L.); (M.-G.W.); (H.Y.)
| | - Qing-Feng Ge
- Industrial Engineering Center for Huaiyang Cuisine of Jiangsu Province, College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China; (R.L.); (G.-Y.W.); (K.-Y.L.); (M.-G.W.); (H.Y.)
- Correspondence: (Q.-F.G.); (W.-B.B.); Tel.: +86-0514-89786171 (Q.-F.G.)
| | - Man-Gang Wu
- Industrial Engineering Center for Huaiyang Cuisine of Jiangsu Province, College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China; (R.L.); (G.-Y.W.); (K.-Y.L.); (M.-G.W.); (H.Y.)
| | - Hai Yu
- Industrial Engineering Center for Huaiyang Cuisine of Jiangsu Province, College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China; (R.L.); (G.-Y.W.); (K.-Y.L.); (M.-G.W.); (H.Y.)
| | - Sheng-Long Wu
- Jiangsu Key Laboratory of Animal Genetic Breeding and Molecular Design, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China;
| | - Wen-Bin Bao
- Jiangsu Key Laboratory of Animal Genetic Breeding and Molecular Design, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China;
- Correspondence: (Q.-F.G.); (W.-B.B.); Tel.: +86-0514-89786171 (Q.-F.G.)
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13
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Jiang H, Hooper C, Kelly M, Steeples V, Simon JN, Beglov J, Azad AJ, Leinhos L, Bennett P, Ehler E, Kalisch-Smith JI, Sparrow DB, Fischer R, Heilig R, Isackson H, Ehsan M, Patone G, Huebner N, Davies B, Watkins H, Gehmlich K. Functional analysis of a gene-edited mouse model to gain insights into the disease mechanisms of a titin missense variant. Basic Res Cardiol 2021; 116:14. [PMID: 33637999 PMCID: PMC7910237 DOI: 10.1007/s00395-021-00853-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/10/2021] [Indexed: 11/03/2022]
Abstract
Titin truncating variants are a well-established cause of cardiomyopathy; however, the role of titin missense variants is less well understood. Here we describe the generation of a mouse model to investigate the underlying disease mechanism of a previously reported titin A178D missense variant identified in a family with non-compaction and dilated cardiomyopathy. Heterozygous and homozygous mice carrying the titin A178D missense variant were characterised in vivo by echocardiography. Heterozygous mice had no detectable phenotype at any time point investigated (up to 1 year). By contrast, homozygous mice developed dilated cardiomyopathy from 3 months. Chronic adrenergic stimulation aggravated the phenotype. Targeted transcript profiling revealed induction of the foetal gene programme and hypertrophic signalling pathways in homozygous mice, and these were confirmed at the protein level. Unsupervised proteomics identified downregulation of telethonin and four-and-a-half LIM domain 2, as well as the upregulation of heat shock proteins and myeloid leukaemia factor 1. Loss of telethonin from the cardiac Z-disc was accompanied by proteasomal degradation; however, unfolded telethonin accumulated in the cytoplasm, leading to a proteo-toxic response in the mice.We show that the titin A178D missense variant is pathogenic in homozygous mice, resulting in cardiomyopathy. We also provide evidence of the disease mechanism: because the titin A178D variant abolishes binding of telethonin, this leads to its abnormal cytoplasmic accumulation. Subsequent degradation of telethonin by the proteasome results in proteasomal overload, and activation of a proteo-toxic response. The latter appears to be a driving factor for the cardiomyopathy observed in the mouse model.
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Affiliation(s)
- He Jiang
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Charlotte Hooper
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Matthew Kelly
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Violetta Steeples
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Jillian N Simon
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Julia Beglov
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Amar J Azad
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Lisa Leinhos
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Pauline Bennett
- Randall Centre for Cell and Molecular Biophysics, School of Cardiovascular Medicine and Sciences, King's College London BHF Centre of Research Excellence, London, UK
| | - Elisabeth Ehler
- Randall Centre for Cell and Molecular Biophysics, School of Cardiovascular Medicine and Sciences, King's College London BHF Centre of Research Excellence, London, UK
| | | | - Duncan B Sparrow
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Roman Fischer
- Nuffield Department of Clinical Medicine, Target Discovery Institute, University of Oxford, Oxford, UK
| | - Raphael Heilig
- Nuffield Department of Clinical Medicine, Target Discovery Institute, University of Oxford, Oxford, UK
| | - Henrik Isackson
- Department of Medical Sciences, Cardiology, Uppsala University, Uppsala, Sweden
- Department of Medical Cell Biology, Integrative Physiology, Uppsala University, Uppsala, Sweden
| | - Mehroz Ehsan
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Giannino Patone
- Max Delbrueck Centre for Molecular Medicine, Berlin, Germany
| | - Norbert Huebner
- Max Delbrueck Centre for Molecular Medicine, Berlin, Germany
| | - Benjamin Davies
- Transgenic Core, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Hugh Watkins
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK
| | - Katja Gehmlich
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, OX3 9DU, UK.
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
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14
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Li Y, Hessel AL, Unger A, Ing D, Recker J, Koser F, Freundt JK, Linke WA. Graded titin cleavage progressively reduces tension and uncovers the source of A-band stability in contracting muscle. eLife 2020; 9:64107. [PMID: 33357376 PMCID: PMC7781594 DOI: 10.7554/elife.64107] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 12/23/2020] [Indexed: 12/11/2022] Open
Abstract
The giant muscle protein titin is a major contributor to passive force; however, its role in active force generation is unresolved. Here, we use a novel titin-cleavage (TC) mouse model that allows specific and rapid cutting of elastic titin to quantify how titin-based forces define myocyte ultrastructure and mechanics. We show that under mechanical strain, as TC doubles from heterozygous to homozygous TC muscles, Z-disks become increasingly out of register while passive and active forces are reduced. Interactions of elastic titin with sarcomeric actin filaments are revealed. Strikingly, when titin-cleaved muscles contract, myosin-containing A-bands become split and adjacent myosin filaments move in opposite directions while also shedding myosins. This establishes intact titin filaments as critical force-transmission networks, buffering the forces observed by myosin filaments during contraction. To perform this function, elastic titin must change stiffness or extensible length, unveiling its fundamental role as an activation-dependent spring in contracting muscle.
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Affiliation(s)
- Yong Li
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Anthony L Hessel
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Andreas Unger
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - David Ing
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Jannik Recker
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Franziska Koser
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Johanna K Freundt
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Wolfgang A Linke
- Institute of Physiology II, University of Muenster, Muenster, Germany
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15
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Popova S, Ulanova A, Gritsyna Y, Salmov N, Rogachevsky V, Mikhailova G, Bobylev A, Bobyleva L, Yutskevich Y, Morenkov O, Zakharova N, Vikhlyantsev I. Predominant synthesis of giant myofibrillar proteins in striated muscles of the long-tailed ground squirrel Urocitellus undulatus during interbout arousal. Sci Rep 2020; 10:15185. [PMID: 32938992 PMCID: PMC7495002 DOI: 10.1038/s41598-020-72127-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 08/24/2020] [Indexed: 12/11/2022] Open
Abstract
Molecular mechanisms underlying muscle-mass retention during hibernation have been extensively discussed in recent years. This work tested the assumption that protein synthesis hyperactivation during interbout arousal of the long-tailed ground squirrel Urocitellus undulatus should be accompanied by increased calpain-1 activity in striated muscles. Calpain-1 is known to be autolysed and activated in parallel. Western blotting detected increased amounts of autolysed calpain-1 fragments in the heart (1.54-fold, p < 0.05) and m. longissimus dorsi (1.8-fold, p < 0.01) of ground squirrels during interbout arousal. The total protein synthesis rate determined by SUnSET declined 3.67-fold in the heart (p < 0.01) and 2.96-fold in m. longissimus dorsi (p < 0.01) during interbout arousal. The synthesis rates of calpain-1 substrates nebulin and titin in muscles did not differ during interbout arousal from those in active summer animals. A recovery of the volume of m. longissimus dorsi muscle fibres, a trend towards a heart-muscle mass increase and a restoration of the normal titin content (reduced in the muscles during hibernation) were observed. The results indicate that hyperactivation of calpain-1 in striated muscles of long-tailed ground squirrels during interbout arousal is accompanied by predominant synthesis of giant sarcomeric cytoskeleton proteins. These changes may contribute to muscle mass retention during hibernation.
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Affiliation(s)
- Svetlana Popova
- Laboratory of the Structure and Functions of Muscle Proteins, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Anna Ulanova
- Laboratory of the Structure and Functions of Muscle Proteins, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Yulia Gritsyna
- Laboratory of the Structure and Functions of Muscle Proteins, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Nikolay Salmov
- Laboratory of the Structure and Functions of Muscle Proteins, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Vadim Rogachevsky
- Laboratory of Signal Perception Mechanisms, Institute of Cell Biophysics, FRC PSCBR, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Gulnara Mikhailova
- Laboratory of the Structure and Functions of Muscle Proteins, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Alexander Bobylev
- Laboratory of the Structure and Functions of Muscle Proteins, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Liya Bobyleva
- Laboratory of the Structure and Functions of Muscle Proteins, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Yana Yutskevich
- Kuban State University, Krasnodar, Krasnodar Krai, 350040, Russia
| | - Oleg Morenkov
- Laboratory of Cell Culture and Tissue Engineering, Institute of Cell Biophysics, FRC PSCBR, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Nadezda Zakharova
- Laboratory of Natural and Artificial Hypobiosis Mechanisms, Institute of Cell Biophysics, FRC PSCBR, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Ivan Vikhlyantsev
- Laboratory of the Structure and Functions of Muscle Proteins, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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16
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Tolkatchev D, Smith GE, Schultz LE, Colpan M, Helms GL, Cort JR, Gregorio CC, Kostyukova AS. Leiomodin creates a leaky cap at the pointed end of actin-thin filaments. PLoS Biol 2020; 18:e3000848. [PMID: 32898131 PMCID: PMC7500696 DOI: 10.1371/journal.pbio.3000848] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 09/18/2020] [Accepted: 08/17/2020] [Indexed: 01/26/2023] Open
Abstract
Improper lengths of actin-thin filaments are associated with altered contractile activity and lethal myopathies. Leiomodin, a member of the tropomodulin family of proteins, is critical in thin filament assembly and maintenance; however, its role is under dispute. Using nuclear magnetic resonance data and molecular dynamics simulations, we generated the first atomic structural model of the binding interface between the tropomyosin-binding site of cardiac leiomodin and the N-terminus of striated muscle tropomyosin. Our structural data indicate that the leiomodin/tropomyosin complex only forms at the pointed end of thin filaments, where the tropomyosin N-terminus is not blocked by an adjacent tropomyosin protomer. This discovery provides evidence supporting the debated mechanism where leiomodin and tropomodulin regulate thin filament lengths by competing for thin filament binding. Data from experiments performed in cardiomyocytes provide additional support for the competition model; specifically, expression of a leiomodin mutant that is unable to interact with tropomyosin fails to displace tropomodulin at thin filament pointed ends and fails to elongate thin filaments. Together with previous structural and biochemical data, we now propose a molecular mechanism of actin polymerization at the pointed end in the presence of bound leiomodin. In the proposed model, the N-terminal actin-binding site of leiomodin can act as a "swinging gate" allowing limited actin polymerization, thus making leiomodin a leaky pointed-end cap. Results presented in this work answer long-standing questions about the role of leiomodin in thin filament length regulation and maintenance.
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Affiliation(s)
- Dmitri Tolkatchev
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, United States of America
| | - Garry E. Smith
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, United States of America
| | - Lauren E. Schultz
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Mert Colpan
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Gregory L. Helms
- The Center for NMR Spectroscopy, Washington State University, Pullman, Washington, United States of America
| | - John R. Cort
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington, United States of America
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, United States of America
| | - Carol C. Gregorio
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Alla S. Kostyukova
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, United States of America
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17
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Bennett P, Rees M, Gautel M. The Axial Alignment of Titin on the Muscle Thick Filament Supports Its Role as a Molecular Ruler. J Mol Biol 2020; 432:4815-4829. [PMID: 32619437 PMCID: PMC7427331 DOI: 10.1016/j.jmb.2020.06.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 01/04/2023]
Abstract
The giant protein titin is expressed in vertebrate striated muscle where it spans half a sarcomere from the Z-disc to the M-band and is essential for muscle organisation, activity and health. The C-terminal portion of titin is closely associated with the thick, myosin-containing filament and exhibits a complex pattern of immunoglobulin and fibronectin domains. This pattern reflects features of the filament organisation suggesting that it acts as a molecular ruler and template, but the exact axial disposition of the molecule has not been determined. Here, we present data that allow us to precisely locate titin domains axially along the thick filament from its tip to the edge of the bare zone. We find that the domains are regularly distributed along the filament at 4-nm intervals and we can determine the domains that associate with features of the filament, such as the 11 stripes of accessory proteins. We confirm that the nine stripes ascribed to myosin binding protein-C are not related to the titin sequence previously assumed; rather, they relate to positions approximately 18 domains further towards the C terminus along titin. This disposition also allows a subgroup of titin domains comprising two or three fibronectin domains to associate with each of the 49 levels of myosin heads in each half filament. The results strongly support the role of titin as a blueprint for the thick filament and the arrangement of the myosin motor domains.
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Affiliation(s)
- Pauline Bennett
- The Randall Centre for Cell & Molecular Biophysics, School of Basic and Medical Biosciences, New Hunt's House, Guy's Campus, King's College London, London, UK.
| | - Martin Rees
- The Randall Centre for Cell & Molecular Biophysics, School of Basic and Medical Biosciences, New Hunt's House, Guy's Campus, King's College London, London, UK.
| | - Mathias Gautel
- The Randall Centre for Cell & Molecular Biophysics, School of Basic and Medical Biosciences, New Hunt's House, Guy's Campus, King's College London, London, UK.
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18
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Dhanyasi N, VijayRaghavan K, Shilo BZ, Schejter ED. Microtubules provide guidance cues for myofibril and sarcomere assembly and growth. Dev Dyn 2020; 250:60-73. [PMID: 32725855 DOI: 10.1002/dvdy.227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/09/2020] [Accepted: 06/20/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Muscle myofibrils and sarcomeres present exceptional examples of highly ordered cytoskeletal filament arrays, whose distinct spatial organization is an essential aspect of muscle cell functionality. We utilized ultra-structural analysis to investigate the assembly of myofibrils and sarcomeres within developing myotubes of the indirect flight musculature of Drosophila. RESULTS A temporal sequence composed of three major processes was identified: subdivision of the unorganized cytoplasm of nascent, multi-nucleated myotubes into distinct organelle-rich and filament-rich domains; initial organization of the filament-rich domains into myofibrils harboring nascent sarcomeric units; and finally, maturation of the highly-ordered pattern of sarcomeric thick (myosin-based) and thin (microfilament-based) filament arrays in parallel to myofibril radial growth. Significantly, organized microtubule arrays were present throughout these stages and exhibited dynamic changes in their spatial patterns consistent with instructive roles. Genetic manipulations confirm these notions, and imply specific and critical guidance activities of the microtubule-based cytoskeleton, as well as structural interdependence between the myosin- and actin-based filament arrays. CONCLUSIONS Our observations highlight a surprisingly significant, behind-the-scenes role for microtubules in establishment of myofibril and sarcomere spatial patterns and size, and provide a detailed account of the interplay between major cytoskeletal elements in generating these essential contractile myogenic units.
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Affiliation(s)
- Nagaraju Dhanyasi
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.,National Centre for Biological Sciences, TIFR, Bangalore, India
| | - K VijayRaghavan
- National Centre for Biological Sciences, TIFR, Bangalore, India
| | - Ben-Zion Shilo
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Eyal D Schejter
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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19
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Rozhkov DO, Zinovyeva OE, Barinov AN, Vikhlyantsev IM, Mikhailova GZ, Penkov NV, Nosovsky AM. Myofascial pain syndrome in female patients with chronic nonspecific back pain: diagnosis and treatment. NEUROLOGY, NEUROPSYCHIATRY, PSYCHOSOMATICS 2020. [DOI: 10.14412/2074-2711-2020-2-57-63] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- D. O. Rozhkov
- Clinic for Nervous System Diseases, Faculty of General Medicine, Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Ministry of Health of Russia
| | - O. E. Zinovyeva
- Department of Nervous System Diseases and Neurosurgery, Faculty of General Medicine, Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Ministry of Health of Russia
| | - A. N. Barinov
- Department of Nervous System Diseases and Neurosurgery, Faculty of General Medicine, Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Ministry of Health of Russia
| | - I. M. Vikhlyantsev
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences;
Pushchino State Natural Science Institute, Pushchino, Moscow Region
| | - G. Z. Mikhailova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences;
Pushchino State Natural Science Institute, Pushchino, Moscow Region
| | - N. V. Penkov
- Institute of Cell Biophysics, Separate Subdivision, Pushchino Biological Research Center, Federal Research Center, Russian Academy of Sciences
| | - A. M. Nosovsky
- Institute of Biomedical Problems, State Research Center of the Russian Federation, Russian Academy of Sciences
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20
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Prill K, Dawson JF. Assembly and Maintenance of Sarcomere Thin Filaments and Associated Diseases. Int J Mol Sci 2020; 21:E542. [PMID: 31952119 PMCID: PMC7013991 DOI: 10.3390/ijms21020542] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/06/2020] [Accepted: 01/12/2020] [Indexed: 12/22/2022] Open
Abstract
Sarcomere assembly and maintenance are essential physiological processes required for cardiac and skeletal muscle function and organism mobility. Over decades of research, components of the sarcomere and factors involved in the formation and maintenance of this contractile unit have been identified. Although we have a general understanding of sarcomere assembly and maintenance, much less is known about the development of the thin filaments and associated factors within the sarcomere. In the last decade, advancements in medical intervention and genome sequencing have uncovered patients with novel mutations in sarcomere thin filaments. Pairing this sequencing with reverse genetics and the ability to generate patient avatars in model organisms has begun to deepen our understanding of sarcomere thin filament development. In this review, we provide a summary of recent findings regarding sarcomere assembly, maintenance, and disease with respect to thin filaments, building on the previous knowledge in the field. We highlight debated and unknown areas within these processes to clearly define open research questions.
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Affiliation(s)
| | - John F. Dawson
- Centre for Cardiovascular Investigations, Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada;
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21
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González-Morales N, Xiao YS, Schilling MA, Marescal O, Liao KA, Schöck F. Myofibril diameter is set by a finely tuned mechanism of protein oligomerization in Drosophila. eLife 2019; 8:50496. [PMID: 31746737 PMCID: PMC6910826 DOI: 10.7554/elife.50496] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 11/18/2019] [Indexed: 11/13/2022] Open
Abstract
Myofibrils are huge cytoskeletal assemblies embedded in the cytosol of muscle cells. They consist of arrays of sarcomeres, the smallest contractile unit of muscles. Within a muscle type, myofibril diameter is highly invariant and contributes to its physiological properties, yet little is known about the underlying mechanisms setting myofibril diameter. Here we show that the PDZ and LIM domain protein Zasp, a structural component of Z-discs, mediates Z-disc and thereby myofibril growth through protein oligomerization. Oligomerization is induced by an interaction of its ZM domain with LIM domains. Oligomerization is terminated upon upregulation of shorter Zasp isoforms which lack LIM domains at later developmental stages. The balance between these two isoforms, which we call growing and blocking isoforms sets the stereotyped diameter of myofibrils. If blocking isoforms dominate, myofibrils become smaller. If growing isoforms dominate, myofibrils and Z-discs enlarge, eventually resulting in large pathological aggregates that disrupt muscle function.
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Affiliation(s)
| | - Yu Shu Xiao
- Department of Biology, McGill University, Montreal, Canada
| | | | | | - Kuo An Liao
- Department of Biology, McGill University, Montreal, Canada
| | - Frieder Schöck
- Department of Biology, McGill University, Montreal, Canada
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22
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Ulanova A, Gritsyna Y, Salmov N, Lomonosova Y, Belova S, Nemirovskaya T, Shenkman B, Vikhlyantsev I. Effect of L-Arginine on Titin Expression in Rat Soleus Muscle After Hindlimb Unloading. Front Physiol 2019; 10:1221. [PMID: 31616317 PMCID: PMC6764413 DOI: 10.3389/fphys.2019.01221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 09/06/2019] [Indexed: 01/18/2023] Open
Abstract
Nitric oxide (NO), produced by NO-synthases via L-arginine oxidation, is an essential trigger for signaling processes involved in structural and metabolic changes in muscle fibers. Recently, it was shown that L-arginine administration prevented the decrease in levels of the muscle cytoskeletal proteins, desmin and dystrophin, in rat soleus muscle after 14 days of hindlimb unloading. Therefore, in this study, we investigated the effect of L-arginine administration on the degree of atrophy changes in the rat soleus muscles under unloading conditions, and on the content, gene expression, and phosphorylation level of titin, the giant protein of striated muscles, able to form a third type of myofilaments—elastic filaments. A 7-day gravitational unloading [hindlimb suspension (HS) group] resulted in a decrease in the soleus weight:body weight ratio (by 31.8%, p < 0.05), indicating muscle atrophy development. The content of intact titin (T1) decreased (by 22.4%, p < 0.05) and the content of proteolytic fragments of titin (T2) increased (by 66.7%, p < 0.05) in the soleus muscle of HS rats, compared to control rats. The titin gene expression and phosphorylation level of titin between these two groups were not significantly different. L-Arginine administration under 7-day gravitational unloading decreased the degree of atrophy changes and also prevented the decrease in levels of T1 in the soleus muscle as compared to HS group. Furthermore, L-arginine administration under unloading resulted in increased titin mRNA level (by 76%, p < 0.05) and decreased phosphorylation level of T2 (by 28%, p < 0.05), compared to those in the HS group. These results suggest that administration of L-arginine, the NO precursor, under unloading decreased the degree of atrophy changes, increased gene expression of titin and prevented the decrease in levels of T1 in the rat soleus muscle. The results can be used to search for approaches to reduce the development of negative changes caused by gravitational unloading in the muscle.
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Affiliation(s)
- Anna Ulanova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia.,Pushchino State Institute of Natural Sciences, Pushchino, Russia
| | - Yuliya Gritsyna
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Nikolai Salmov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Yuliya Lomonosova
- State Scientific Center RF, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Svetlana Belova
- State Scientific Center RF, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Tatyana Nemirovskaya
- State Scientific Center RF, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Boris Shenkman
- State Scientific Center RF, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Ivan Vikhlyantsev
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
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23
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Dowling P, Zweyer M, Swandulla D, Ohlendieck K. Characterization of Contractile Proteins from Skeletal Muscle Using Gel-Based Top-Down Proteomics. Proteomes 2019; 7:proteomes7020025. [PMID: 31226838 PMCID: PMC6631179 DOI: 10.3390/proteomes7020025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/14/2019] [Accepted: 06/17/2019] [Indexed: 12/22/2022] Open
Abstract
The mass spectrometric analysis of skeletal muscle proteins has used both peptide-centric and protein-focused approaches. The term 'top-down proteomics' is often used in relation to studying purified proteoforms and their post-translational modifications. Two-dimensional gel electrophoresis, in combination with peptide generation for the identification and characterization of intact proteoforms being present in two-dimensional spots, plays a critical role in specific applications of top-down proteomics. A decisive bioanalytical advantage of gel-based and top-down approaches is the initial bioanalytical focus on intact proteins, which usually enables the swift identification and detailed characterisation of specific proteoforms. In this review, we describe the usage of two-dimensional gel electrophoretic top-down proteomics and related approaches for the systematic analysis of key components of the contractile apparatus, with a special focus on myosin heavy and light chains and their associated regulatory proteins. The detailed biochemical analysis of proteins belonging to the thick and thin skeletal muscle filaments has decisively improved our biochemical understanding of structure-function relationships within the contractile apparatus. Gel-based and top-down proteomics has clearly established a variety of slow and fast isoforms of myosin, troponin and tropomyosin as excellent markers of fibre type specification and dynamic muscle transition processes.
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Affiliation(s)
- Paul Dowling
- Department of Biology, Maynooth University, Maynooth, W23F2H6 Co. Kildare, Ireland.
- MU Human Health Research Institute, Maynooth University, Maynooth, W23F2H6 Co. Kildare, Ireland.
| | - Margit Zweyer
- Institute of Physiology II, University of Bonn, D-53115 Bonn, Germany.
| | - Dieter Swandulla
- Institute of Physiology II, University of Bonn, D-53115 Bonn, Germany.
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, Maynooth, W23F2H6 Co. Kildare, Ireland.
- MU Human Health Research Institute, Maynooth University, Maynooth, W23F2H6 Co. Kildare, Ireland.
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24
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Dasbiswas K, Hu S, Schnorrer F, Safran SA, Bershadsky AD. Ordering of myosin II filaments driven by mechanical forces: experiments and theory. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0114. [PMID: 29632266 DOI: 10.1098/rstb.2017.0114] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/30/2017] [Indexed: 12/27/2022] Open
Abstract
Myosin II filaments form ordered superstructures in both cross-striated muscle and non-muscle cells. In cross-striated muscle, myosin II (thick) filaments, actin (thin) filaments and elastic titin filaments comprise the stereotypical contractile units of muscles called sarcomeres. Linear chains of sarcomeres, called myofibrils, are aligned laterally in registry to form cross-striated muscle cells. The experimentally observed dependence of the registered organization of myofibrils on extracellular matrix elasticity has been proposed to arise from the interactions of sarcomeric contractile elements (considered as force dipoles) through the matrix. Non-muscle cells form small bipolar filaments built of less than 30 myosin II molecules. These filaments are associated in registry forming superstructures ('stacks') orthogonal to actin filament bundles. Formation of myosin II filament stacks requires the myosin II ATPase activity and function of the actin filament crosslinking, polymerizing and depolymerizing proteins. We propose that the myosin II filaments embedded into elastic, intervening actin network (IVN) function as force dipoles that interact attractively through the IVN. This is in analogy with the theoretical picture developed for myofibrils where the elastic medium is now the actin cytoskeleton itself. Myosin stack formation in non-muscle cells provides a novel mechanism for the self-organization of the actin cytoskeleton at the level of the entire cell.This article is part of the theme issue 'Self-organization in cell biology'.
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Affiliation(s)
- Kinjal Dasbiswas
- James Franck Institute, University of Chicago, Chicago, IL 60637, USA
| | - Shiqiong Hu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Republic of Singapore.,Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Frank Schnorrer
- Aix Marseille University, CNRS, IBDM, 13288 Marseille, France
| | - Samuel A Safran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alexander D Bershadsky
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Republic of Singapore .,Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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25
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Nikonova E, Kao SY, Ravichandran K, Wittner A, Spletter ML. Conserved functions of RNA-binding proteins in muscle. Int J Biochem Cell Biol 2019; 110:29-49. [PMID: 30818081 DOI: 10.1016/j.biocel.2019.02.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 02/21/2019] [Accepted: 02/23/2019] [Indexed: 12/13/2022]
Abstract
Animals require different types of muscle for survival, for example for circulation, motility, reproduction and digestion. Much emphasis in the muscle field has been placed on understanding how transcriptional regulation generates diverse types of muscle during development. Recent work indicates that alternative splicing and RNA regulation are as critical to muscle development, and altered function of RNA-binding proteins causes muscle disease. Although hundreds of genes predicted to bind RNA are expressed in muscles, many fewer have been functionally characterized. We present a cross-species view summarizing what is known about RNA-binding protein function in muscle, from worms and flies to zebrafish, mice and humans. In particular, we focus on alternative splicing regulated by the CELF, MBNL and RBFOX families of proteins. We discuss the systemic nature of diseases associated with loss of RNA-binding proteins in muscle, focusing on mis-regulation of CELF and MBNL in myotonic dystrophy. These examples illustrate the conservation of RNA-binding protein function and the marked utility of genetic model systems in understanding mechanisms of RNA regulation.
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Affiliation(s)
- Elena Nikonova
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany
| | - Shao-Yen Kao
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany
| | - Keshika Ravichandran
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany
| | - Anja Wittner
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany
| | - Maria L Spletter
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany; Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany.
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26
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Murphy S, Dowling P, Zweyer M, Swandulla D, Ohlendieck K. Proteomic profiling of giant skeletal muscle proteins. Expert Rev Proteomics 2019; 16:241-256. [DOI: 10.1080/14789450.2019.1575205] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Sandra Murphy
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Ireland
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Ireland
| | - Margit Zweyer
- Institute of Physiology II, University of Bonn, Bonn, Germany
| | | | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Ireland
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27
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Rall JA. What makes skeletal muscle striated? Discoveries in the endosarcomeric and exosarcomeric cytoskeleton. ADVANCES IN PHYSIOLOGY EDUCATION 2018; 42:672-684. [PMID: 30431326 DOI: 10.1152/advan.00152.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
One of the most iconic images in biology is the cross-striated appearance of a skeletal muscle fiber. The repeating band pattern shows that all of the sarcomeres are the same length. All of the A bands are the same length and are located in the middle of the sarcomeres. Furthermore, all of the myofibrils are transversely aligned across the muscle fiber. It has been known for 300 yr that skeletal muscle is striated, but only in the last 40 yr has a molecular understanding of the striations emerged. In the 1950s it was discovered that the extraction of myosin from myofibrils abolished the A bands, and the myofibrils were no longer striated. With the further extraction of actin, only the Z disks remained. Strangely, the sarcomere length did not change, and these "ghost" myofibrils still exhibited elastic behavior. The breakthrough came in the 1970s with the discovery of the gigantic protein titin. Titin, an elastic protein ~1 µm in length, runs from the Z disk to the middle of the A band and ensures that each sarcomere is the same length. Titin anchors the A band in the middle of the sarcomere and may determine thick-filament length and thus A-band length. In the 1970s it was proposed that the intermediate filament desmin, which surrounds the Z disks, connects adjacent myofibrils, resulting in the striated appearance of a skeletal muscle fiber.
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Affiliation(s)
- Jack A Rall
- Department of Physiology and Cell Biology, College of Medicine, Ohio State University , Columbus, Ohio
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28
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Kellermayer M, Sziklai D, Papp Z, Decker B, Lakatos E, Mártonfalvi Z. Topology of interaction between titin and myosin thick filaments. J Struct Biol 2018; 203:46-53. [PMID: 29738832 DOI: 10.1016/j.jsb.2018.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 04/30/2018] [Accepted: 05/04/2018] [Indexed: 01/01/2023]
Abstract
Titin is a giant protein spanning between the Z- and M-lines of the sarcomere. In the A-band titin is associated with the myosin thick filament. It has been speculated that titin may serve as a blueprint for thick-filament formation due to the super-repeat structure of its A-band domains. Accordingly, titin might provide a template that determines the length and structural periodicity of the thick filament. Here we tested the titin ruler hypothesis by mixing titin and myosin at in situ stoichiometric ratios (300 myosins per 12 titins) in buffers of different ionic strength (KCl concentration range 100-300 mM). The topology of the filamentous complexes was investigated with atomic force microscopy. We found that the samples contained distinct, segregated populations of titin molecules and myosin thick filaments. We were unable to identify complexes in which myosin molecules were regularly associated to either mono- or oligomeric titin in either relaxed or stretched states of the titin filaments. Thus, the electrostatically driven self-association is stronger in both myosin and titin than their binding to each other, and it is unlikely that titin functions as a geometrical template for thick-filament formation. However, when allowed to equilibrate configurationally, long myosin thick filaments appeared with titin oligomers attached to their surface. The titin meshwork formed on the thick-filament surface may play a role in controlling thick-filament length by regulating the structural dynamics of myosin molecules and placing a mechanical limit on the filament length.
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Affiliation(s)
- Miklós Kellermayer
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest H1094, Hungary.
| | - Dominik Sziklai
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest H1094, Hungary
| | - Zsombor Papp
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest H1094, Hungary
| | - Brennan Decker
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest H1094, Hungary
| | - Eszter Lakatos
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest H1094, Hungary
| | - Zsolt Mártonfalvi
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest H1094, Hungary
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29
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Wang L, Geist J, Grogan A, Hu LYR, Kontrogianni-Konstantopoulos A. Thick Filament Protein Network, Functions, and Disease Association. Compr Physiol 2018; 8:631-709. [PMID: 29687901 PMCID: PMC6404781 DOI: 10.1002/cphy.c170023] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sarcomeres consist of highly ordered arrays of thick myosin and thin actin filaments along with accessory proteins. Thick filaments occupy the center of sarcomeres where they partially overlap with thin filaments. The sliding of thick filaments past thin filaments is a highly regulated process that occurs in an ATP-dependent manner driving muscle contraction. In addition to myosin that makes up the backbone of the thick filament, four other proteins which are intimately bound to the thick filament, myosin binding protein-C, titin, myomesin, and obscurin play important structural and regulatory roles. Consistent with this, mutations in the respective genes have been associated with idiopathic and congenital forms of skeletal and cardiac myopathies. In this review, we aim to summarize our current knowledge on the molecular structure, subcellular localization, interacting partners, function, modulation via posttranslational modifications, and disease involvement of these five major proteins that comprise the thick filament of striated muscle cells. © 2018 American Physiological Society. Compr Physiol 8:631-709, 2018.
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Affiliation(s)
- Li Wang
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Janelle Geist
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Alyssa Grogan
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Li-Yen R. Hu
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
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30
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Tonino P, Kiss B, Strom J, Methawasin M, Smith JE, Kolb J, Labeit S, Granzier H. The giant protein titin regulates the length of the striated muscle thick filament. Nat Commun 2017; 8:1041. [PMID: 29051486 PMCID: PMC5648799 DOI: 10.1038/s41467-017-01144-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 08/22/2017] [Indexed: 01/13/2023] Open
Abstract
The contractile machinery of heart and skeletal muscles has as an essential component the thick filament, comprised of the molecular motor myosin. The thick filament is of a precisely controlled length, defining thereby the force level that muscles generate and how this force varies with muscle length. It has been speculated that the mechanism by which thick filament length is controlled involves the giant protein titin, but no conclusive support for this hypothesis exists. Here we show that in a mouse model in which we deleted two of titin’s C-zone super-repeats, thick filament length is reduced in cardiac and skeletal muscles. In addition, functional studies reveal reduced force generation and a dilated cardiomyopathy (DCM) phenotype. Thus, regulation of thick filament length depends on titin and is critical for maintaining muscle health. Thick filaments in skeletal muscle and heart are composed of myosin. The authors show that the length of thick filaments is defined by titin, and that alterations in titin length affect force generation and lead to dilated cardiomyopathy in mice.
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Affiliation(s)
- Paola Tonino
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, 85721, USA.,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona, 85721, USA
| | - Balazs Kiss
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, 85721, USA.,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona, 85721, USA
| | - Josh Strom
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, 85721, USA.,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona, 85721, USA
| | - Mei Methawasin
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, 85721, USA.,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona, 85721, USA
| | - John E Smith
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, 85721, USA.,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona, 85721, USA
| | - Justin Kolb
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, 85721, USA.,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona, 85721, USA
| | - Siegfried Labeit
- Department of Integrative Pathophysiology, Medical Faculty Mannheim, Mannheim, 68167, Germany.,DZHK, Mannheim-Heidelberg, 68167, Germany
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, 85721, USA. .,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, Arizona, 85721, USA.
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31
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Gritsyna YV, Salmov NN, Bobylev AG, Ulanova AD, Kukushkin NI, Podlubnaya ZA, Vikhlyantsev IM. Increased Autolysis ofμ-Calpain in Skeletal Muscles of Chronic Alcohol-Fed Rats. Alcohol Clin Exp Res 2017; 41:1686-1694. [DOI: 10.1111/acer.13476] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 08/04/2017] [Indexed: 01/31/2023]
Affiliation(s)
- Yulia V. Gritsyna
- Laboratory of Structure and Functions of Muscle Proteins; Institute of Theoretical and Experimental Biophysics; Russian Academy of Sciences; Pushchino Russia
| | - Nikolay N. Salmov
- Laboratory of Structure and Functions of Muscle Proteins; Institute of Theoretical and Experimental Biophysics; Russian Academy of Sciences; Pushchino Russia
| | - Alexander G. Bobylev
- Laboratory of Structure and Functions of Muscle Proteins; Institute of Theoretical and Experimental Biophysics; Russian Academy of Sciences; Pushchino Russia
- Pushchino State Institute of Natural Science; Pushchino Russia
| | - Anna D. Ulanova
- Laboratory of Structure and Functions of Muscle Proteins; Institute of Theoretical and Experimental Biophysics; Russian Academy of Sciences; Pushchino Russia
- Pushchino State Institute of Natural Science; Pushchino Russia
| | - Nikolay I. Kukushkin
- Laboratory of Cell Cultures and Cell Engineering; Institute of Cell Biophysics; Russian Academy of Sciences; Pushchino Russia
| | - Zoya A. Podlubnaya
- Laboratory of Structure and Functions of Muscle Proteins; Institute of Theoretical and Experimental Biophysics; Russian Academy of Sciences; Pushchino Russia
- Pushchino State Institute of Natural Science; Pushchino Russia
| | - Ivan M. Vikhlyantsev
- Laboratory of Structure and Functions of Muscle Proteins; Institute of Theoretical and Experimental Biophysics; Russian Academy of Sciences; Pushchino Russia
- Pushchino State Institute of Natural Science; Pushchino Russia
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32
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Abstract
Coiled coils appear in countless structural contexts, as appendages to small proteins, as parts of multi-domain proteins, and as building blocks of filaments. Although their structure is unpretentious and their basic properties are understood in great detail, the spectrum of functional properties they provide in different proteins has become increasingly complex. This chapter aims to depict this functional spectrum, to identify common themes and their molecular basis, with an emphasis on new insights gained into dynamic aspects.
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Affiliation(s)
- Marcus D Hartmann
- Max Planck Institute for Developmental Biology, Spemannstraße 35, 72076, Tübingen, Germany.
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