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Cubuk J, Greenberg L, Greenberg AE, Emenecker RJ, Stuchell-Brereton MD, Holehouse AS, Soranno A, Greenberg MJ. Structural dynamics of the intrinsically disordered linker region of cardiac troponin T. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596451. [PMID: 38853835 PMCID: PMC11160775 DOI: 10.1101/2024.05.30.596451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The cardiac troponin complex, composed of troponins I, T, and C, plays a central role in regulating the calcium-dependent interactions between myosin and the thin filament. Mutations in troponin can cause cardiomyopathies; however, it is still a major challenge for the field to connect how changes in sequence affect troponin's function. Recent high-resolution structures of the thin filament revealed critical insights into the structure-function relationship of the troponin complex, but there remain large, unresolved segments of troponin, including the troponin-T linker region that is a hotspot for several cardiomyopathy mutations. This unresolved yet functionally-significant linker region has been proposed to be intrinsically disordered, with behaviors that are not well described by traditional structural approaches; however, this proposal has not been experimentally verified. Here, we used a combination of single-molecule Förster resonance energy transfer (FRET), molecular dynamics simulations, and functional reconstitution assays to investigate the troponin-T linker region. We experimentally and computationally show that in the context of both isolated troponin and the fully regulated troponin complex, the linker behaves as a dynamic, intrinsically disordered region. This region undergoes polyampholyte expansion in the presence of high salt and distinct conformational changes during the assembly of the troponin complex. We also examine the ΔE160 hypertrophic cardiomyopathy mutation in the linker, and we demonstrate that this mutation does not affect the conformational dynamics of the linker, rather it allosterically affects interactions with other subunits of the troponin complex, leading to increased molecular contractility. Taken together, our data clearly demonstrate the importance of disorder within the troponin-T linker and provide new insights into the molecular mechanisms controlling the pathogenesis of cardiomyopathies.
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Affiliation(s)
- Jasmine Cubuk
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, 660 Euclid Ave, 63110, Saint Louis, MO, USA
- Center for Biomolecular Condensates, Washington University in St Louis, 1 Brookings Drive, 63130, Saint Louis, MO, USA
| | - Lina Greenberg
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, 660 Euclid Ave, 63110, Saint Louis, MO, USA
| | - Akiva E. Greenberg
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, 660 Euclid Ave, 63110, Saint Louis, MO, USA
| | - Ryan J. Emenecker
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, 660 Euclid Ave, 63110, Saint Louis, MO, USA
- Center for Biomolecular Condensates, Washington University in St Louis, 1 Brookings Drive, 63130, Saint Louis, MO, USA
| | - Melissa D. Stuchell-Brereton
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, 660 Euclid Ave, 63110, Saint Louis, MO, USA
- Center for Biomolecular Condensates, Washington University in St Louis, 1 Brookings Drive, 63130, Saint Louis, MO, USA
| | - Alex S. Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, 660 Euclid Ave, 63110, Saint Louis, MO, USA
- Center for Biomolecular Condensates, Washington University in St Louis, 1 Brookings Drive, 63130, Saint Louis, MO, USA
| | - Andrea Soranno
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, 660 Euclid Ave, 63110, Saint Louis, MO, USA
- Center for Biomolecular Condensates, Washington University in St Louis, 1 Brookings Drive, 63130, Saint Louis, MO, USA
| | - Michael J. Greenberg
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, 660 Euclid Ave, 63110, Saint Louis, MO, USA
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2
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Yang Z, Marston SB, Gould IR. Modulation of Structure and Dynamics of Cardiac Troponin by Phosphorylation and Mutations Revealed by Molecular Dynamics Simulations. J Phys Chem B 2023; 127:8736-8748. [PMID: 37791815 PMCID: PMC10591477 DOI: 10.1021/acs.jpcb.3c02337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 09/08/2023] [Indexed: 10/05/2023]
Abstract
Adrenaline acts on β1 receptors in the heart muscle to enhance contractility, increase the heart rate, and increase the rate of relaxation (lusitropy) via activation of the cyclic AMP-dependent protein kinase, PKA. Phosphorylation of serines 22 and 23 in the N-terminal peptide of cardiac troponin I is responsible for lusitropy. Mutations associated with cardiomyopathy suppress the phosphorylation-dependent change. Key parts of troponin responsible for this modulatory system are disordered and cannot be resolved by conventional structural approaches. We performed all-atom molecular dynamics simulations (5 × 1.5 μs runs) of the troponin core (419 amino acids) in the presence of Ca2+ in the bisphosphorylated and unphosphorylated states for both wild-type troponin and the troponin C (cTnC) G159D mutant. PKA phosphorylation affects troponin dynamics. There is significant rigidification of the structure involving rearrangement of the cTnI(1-33)-cTnC interaction and changes in the distribution of the cTnC helix A/B angle, troponin I (cTnI) switch peptide (149-164) docking, and the angle between the regulatory head and ITC arm domains. The familial dilated cardiomyopathy cTnC G159D mutation whose Ca2+ sensitivity is not modulated by cTnI phosphorylation exhibits a structure inherently more rigid than the wild type, with phosphorylation reversing the direction of all metrics relative to the wild type.
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Affiliation(s)
- Zeyu Yang
- Department
of Chemistry, Molecular Sciences Research Hub, Imperial College London, Shepherd’s Bush, London W12 0BZ, U.K.
- Institute
of Chemical Biology, Molecular Sciences Research Hub, Imperial College London, Shepherd’s Bush, London W12 0BZ, U.K.
| | - Steven B. Marston
- National
Heart & Lung Institute, Imperial College
London, London W12 0NN, U.K.
| | - Ian R. Gould
- Department
of Chemistry, Molecular Sciences Research Hub, Imperial College London, Shepherd’s Bush, London W12 0BZ, U.K.
- Institute
of Chemical Biology, Molecular Sciences Research Hub, Imperial College London, Shepherd’s Bush, London W12 0BZ, U.K.
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3
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Sun B, Kekenes-Huskey PM. Myofilament-associated proteins with intrinsic disorder (MAPIDs) and their resolution by computational modeling. Q Rev Biophys 2023; 56:e2. [PMID: 36628457 PMCID: PMC11070111 DOI: 10.1017/s003358352300001x] [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] [Indexed: 01/12/2023]
Abstract
The cardiac sarcomere is a cellular structure in the heart that enables muscle cells to contract. Dozens of proteins belong to the cardiac sarcomere, which work in tandem to generate force and adapt to demands on cardiac output. Intriguingly, the majority of these proteins have significant intrinsic disorder that contributes to their functions, yet the biophysics of these intrinsically disordered regions (IDRs) have been characterized in limited detail. In this review, we first enumerate these myofilament-associated proteins with intrinsic disorder (MAPIDs) and recent biophysical studies to characterize their IDRs. We secondly summarize the biophysics governing IDR properties and the state-of-the-art in computational tools toward MAPID identification and characterization of their conformation ensembles. We conclude with an overview of future computational approaches toward broadening the understanding of intrinsic disorder in the cardiac sarcomere.
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Affiliation(s)
- Bin Sun
- Research Center for Pharmacoinformatics (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Department of Medicinal Chemistry and Natural Medicine Chemistry, College of Pharmacy, Harbin Medical University, Harbin 150081, China
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4
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Mier P, Paladin L, Tamana S, Petrosian S, Hajdu-Soltész B, Urbanek A, Gruca A, Plewczynski D, Grynberg M, Bernadó P, Gáspári Z, Ouzounis CA, Promponas VJ, Kajava AV, Hancock JM, Tosatto SCE, Dosztanyi Z, Andrade-Navarro MA. Disentangling the complexity of low complexity proteins. Brief Bioinform 2021; 21:458-472. [PMID: 30698641 PMCID: PMC7299295 DOI: 10.1093/bib/bbz007] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/19/2018] [Accepted: 01/07/2019] [Indexed: 12/31/2022] Open
Abstract
There are multiple definitions for low complexity regions (LCRs) in protein sequences, with all of them broadly considering LCRs as regions with fewer amino acid types compared to an average composition. Following this view, LCRs can also be defined as regions showing composition bias. In this critical review, we focus on the definition of sequence complexity of LCRs and their connection with structure. We present statistics and methodological approaches that measure low complexity (LC) and related sequence properties. Composition bias is often associated with LC and disorder, but repeats, while compositionally biased, might also induce ordered structures. We illustrate this dichotomy, and more generally the overlaps between different properties related to LCRs, using examples. We argue that statistical measures alone cannot capture all structural aspects of LCRs and recommend the combined usage of a variety of predictive tools and measurements. While the methodologies available to study LCRs are already very advanced, we foresee that a more comprehensive annotation of sequences in the databases will enable the improvement of predictions and a better understanding of the evolution and the connection between structure and function of LCRs. This will require the use of standards for the generation and exchange of data describing all aspects of LCRs. Short abstract There are multiple definitions for low complexity regions (LCRs) in protein sequences. In this critical review, we focus on the definition of sequence complexity of LCRs and their connection with structure. We present statistics and methodological approaches that measure low complexity (LC) and related sequence properties. Composition bias is often associated with LC and disorder, but repeats, while compositionally biased, might also induce ordered structures. We illustrate this dichotomy, plus overlaps between different properties related to LCRs, using examples.
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Affiliation(s)
- Pablo Mier
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Lisanna Paladin
- Department of Biomedical Science, University of Padova, Padova, Italy
| | - Stella Tamana
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Sophia Petrosian
- Biological Computation and Process Laboratory, Chemical Process & Energy Resources Institute, Centre for Research & Technology Hellas, Thessalonica, Greece
| | - Borbála Hajdu-Soltész
- MTA-ELTE Lendület Bioinformatics Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | - Annika Urbanek
- Centre de Biochimie Structurale, INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Aleksandra Gruca
- Institute of Informatics, Silesian University of Technology, Gliwice, Poland
| | - Dariusz Plewczynski
- Center of New Technologies, University of Warsaw, Warsaw, Poland.,Faculty of Mathematics and Information Science, Warsaw University of Technology, Warsaw, Poland
| | | | - Pau Bernadó
- Centre de Biochimie Structurale, INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Zoltán Gáspári
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Christos A Ouzounis
- Biological Computation and Process Laboratory, Chemical Process & Energy Resources Institute, Centre for Research & Technology Hellas, Thessalonica, Greece
| | - Vasilis J Promponas
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Andrey V Kajava
- Centre de Recherche en Biologie Cellulaire de Montpellier, CNRS-UMR, Institut de Biologie Computationnelle, Universite de Montpellier, Montpellier, France.,Institute of Bioengineering, University ITMO, St. Petersburg, Russia
| | - John M Hancock
- Earlham Institute, Norwich, UK.,ELIXIR Hub, Welcome Genome Campus, Hinxton, UK
| | - Silvio C E Tosatto
- Department of Biomedical Science, University of Padova, Padova, Italy.,CNR Institute of Neuroscience, Padova, Italy
| | - Zsuzsanna Dosztanyi
- MTA-ELTE Lendület Bioinformatics Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | - Miguel A Andrade-Navarro
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University of Mainz, Mainz, Germany
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5
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Lambert M, Claeyssen C, Bastide B, Cieniewski‐Bernard C. O-GlcNAcylation as a regulator of the functional and structural properties of the sarcomere in skeletal muscle: An update review. Acta Physiol (Oxf) 2020; 228:e13301. [PMID: 31108020 DOI: 10.1111/apha.13301] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/03/2019] [Accepted: 05/10/2019] [Indexed: 12/15/2022]
Abstract
Although the O-GlcNAcylation process was discovered in 1984, its potential role in the physiology and physiopathology of skeletal muscle only emerged 20 years later. An increasing number of publications strongly support a key role of O-GlcNAcylation in the modulation of important cellular processes which are essential for skeletal muscle functions. Indeed, over a thousand of O-GlcNAcylated proteins have been identified within skeletal muscle since 2004, which belong to various classes of proteins, including sarcomeric proteins. In this review, we focused on these myofibrillar proteins, including contractile and structural proteins. Because of the modification of motor and regulatory proteins, the regulatory myosin light chain (MLC2) is related to several reports that support a key role of O-GlcNAcylation in the fine modulation of calcium activation parameters of skeletal muscle fibres, depending on muscle phenotype and muscle work. In addition, another key function of O-GlcNAcylation has recently emerged in the regulation of organization and reorganization of the sarcomere. Altogether, this data support a key role of O-GlcNAcylation in the homeostasis of sarcomeric cytoskeleton, known to be disturbed in many related muscle disorders.
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Affiliation(s)
- Matthias Lambert
- Univ. Lille, EA 7369 ‐ URePSSS ‐ Unité de Recherche Pluridisciplinaire Sport Santé Société Lille France
| | - Charlotte Claeyssen
- Univ. Lille, EA 7369 ‐ URePSSS ‐ Unité de Recherche Pluridisciplinaire Sport Santé Société Lille France
| | - Bruno Bastide
- Univ. Lille, EA 7369 ‐ URePSSS ‐ Unité de Recherche Pluridisciplinaire Sport Santé Société Lille France
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6
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Johnston JR, Landim-Vieira M, Marques MA, de Oliveira GAP, Gonzalez-Martinez D, Moraes AH, He H, Iqbal A, Wilnai Y, Birk E, Zucker N, Silva JL, Chase PB, Pinto JR. The intrinsically disordered C terminus of troponin T binds to troponin C to modulate myocardial force generation. J Biol Chem 2019; 294:20054-20069. [PMID: 31748410 PMCID: PMC6937556 DOI: 10.1074/jbc.ra119.011177] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/13/2019] [Indexed: 12/15/2022] Open
Abstract
Aberrant regulation of myocardial force production represents an early biomechanical defect associated with sarcomeric cardiomyopathies, but the molecular mechanisms remain poorly defined. Here, we evaluated the pathogenicity of a previously unreported sarcomeric gene variant identified in a pediatric patient with sporadic dilated cardiomyopathy, and we determined a molecular mechanism. Trio whole-exome sequencing revealed a de novo missense variant in TNNC1 that encodes a p.I4M substitution in the N-terminal helix of cardiac troponin C (cTnC). Reconstitution of this human cTnC variant into permeabilized porcine cardiac muscle preparations significantly decreases the magnitude and rate of isometric force generation at physiological Ca2+-activation levels. Computational modeling suggests that this inhibitory effect can be explained by a decrease in the rates of cross-bridge attachment and detachment. For the first time, we show that cardiac troponin T (cTnT), in part through its intrinsically disordered C terminus, directly binds to WT cTnC, and we find that this cardiomyopathic variant displays tighter binding to cTnT. Steady-state fluorescence and NMR spectroscopy studies suggest that this variant propagates perturbations in cTnC structural dynamics to distal regions of the molecule. We propose that the intrinsically disordered C terminus of cTnT directly interacts with the regulatory N-domain of cTnC to allosterically modulate Ca2+ activation of force, perhaps by controlling the troponin I switching mechanism of striated muscle contraction. Alterations in cTnC-cTnT binding may compromise contractile performance and trigger pathological remodeling of the myocardium.
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Affiliation(s)
- Jamie R Johnston
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida 32306
| | - Maicon Landim-Vieira
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida 32306
| | - Mayra A Marques
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Instituto Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Guilherme A P de Oliveira
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Instituto Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - David Gonzalez-Martinez
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida 32306
| | - Adolfo H Moraes
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Huan He
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida 32306
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306
| | - Anwar Iqbal
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Instituto Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Yael Wilnai
- Department of Pediatrics, Dana-Dwek ChildrenγÇÖs Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel 6423906
| | - Einat Birk
- Department of Cardiology, Schneider ChildrenγÇÖs Medical Center, Tel Aviv University, Petah Tikva, Israel 4920235
| | - Nili Zucker
- Department of Cardiology, Schneider ChildrenγÇÖs Medical Center, Tel Aviv University, Petah Tikva, Israel 4920235
| | - Jerson L Silva
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Instituto Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - P Bryant Chase
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306
| | - Jose Renato Pinto
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida 32306
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7
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Bowman JD, Lindert S. Computational Studies of Cardiac and Skeletal Troponin. Front Mol Biosci 2019; 6:68. [PMID: 31448287 PMCID: PMC6696891 DOI: 10.3389/fmolb.2019.00068] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/25/2019] [Indexed: 12/16/2022] Open
Abstract
Troponin is a key regulatory protein in muscle contraction, consisting of three subunits troponin C (TnC), troponin I (TnI), and troponin T (TnT). Calcium association to TnC initiates contraction by causing a series of dynamic and conformational changes that allow the switch peptide of TnI to bind and subsequently cross bridges to form between the thin and thick filament of the sarcomere. Owing to its pivotal role in contraction regulation, troponin has been the focus of numerous computational studies over the last decade. These studies elegantly supplemented a large volume of experimental work and focused on the structure, dynamics and function of the whole troponin complex, individual subunits, and even on segments of the thin filament. Molecular dynamics, Brownian dynamics, and free energy simulations have been used to elucidate the conformational dynamics and underlying free energy landscape of troponin, calcium, and switch peptide binding, as well as the effect of disease mutations, small molecules and post-translational modifications such as phosphorylation. Frequently, simulations have been used to confirm or explain experimental observations. Computer-aided drug discovery tools have been employed to identify novel potential calcium sensitizing agents binding to the TnC-TnI interface. Finally, Markov modeling has contributed to simulating contraction within the sarcomere on the mesoscale. Here we are reviewing and classifying the existing computational work on troponin and its subunits, outline current gaps in simulations elucidating troponin's role in contraction and suggest potential future developments in the field.
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Affiliation(s)
- Jacob D Bowman
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, United States
| | - Steffen Lindert
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, United States
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8
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The Structural and Functional Diversity of Intrinsically Disordered Regions in Transmembrane Proteins. J Membr Biol 2019; 252:273-292. [DOI: 10.1007/s00232-019-00069-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/17/2019] [Indexed: 10/26/2022]
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9
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Marques MA, Parvatiyar MS, Yang W, de Oliveira GAP, Pinto JR. The missing links within troponin. Arch Biochem Biophys 2018; 663:95-100. [PMID: 30584890 DOI: 10.1016/j.abb.2018.12.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/18/2018] [Accepted: 12/21/2018] [Indexed: 01/02/2023]
Abstract
The cardiac contraction-relaxation cycle is controlled by a sophisticated set of machinery. Of particular interest, is the revelation that allosteric networks transmit effects of binding at one site to influence troponin complex dynamics and structural-mediated signaling in often distal, functional sites in the myofilament. Our recent observations provide compelling evidence that allostery can explain the function of large-scale macromolecular events. Here we elaborate on our recent findings of interdomain communication within troponin C, using cutting-edge structural biology approaches, and highlight the importance of unveiling the unknown, distant communication networks within this system to obtain more comprehensive knowledge of how allostery impacts cardiac physiology and disease.
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Affiliation(s)
- Mayra A Marques
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Michelle S Parvatiyar
- Department of Nutrition, Food and Exercise Sciences, Florida State University, 107 Chieftan Way, Tallahassee, FL, 32306-1493, USA
| | - Wei Yang
- Department of Chemistry and Biochemistry and Institute of Molecular Biophysics, Florida State University, Kasha Laboratory Building, 91 Chieftan Way, Tallahassee, FL, 32306-4380, USA
| | - Guilherme A P de Oliveira
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, 22908-0733, USA.
| | - Jose R Pinto
- Department of Biomedical Sciences, Florida State University College of Medicine, 1115 West Call Street, Tallahassee, FL, 32306-4300, USA.
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10
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Janssens JV, Ma B, Brimble MA, Van Eyk JE, Delbridge LMD, Mellor KM. Cardiac troponins may be irreversibly modified by glycation: novel potential mechanisms of cardiac performance modulation. Sci Rep 2018; 8:16084. [PMID: 30382112 PMCID: PMC6208411 DOI: 10.1038/s41598-018-33886-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 08/31/2018] [Indexed: 02/07/2023] Open
Abstract
Dynamic movements of the cardiac troponin complex are an important component of the cardiac cycle. Whether cardiac troponins are subjected to irreversible advanced glycation end-product (AGE) modification is unknown. This study interrogated human and rat cardiac troponin-C, troponin-I and troponin-T to identify endogenous AGE modifications using mass spectrometry (LC-MS/MS). AGE modifications were detected on two amino acid residues of human troponin-C (Lys6, Lys39), thirteen troponin-I residues (Lys36, Lys50, Lys58, Arg79, Lys117, Lys120, Lys131, Arg148, Arg162, Lys164, Lys183, Lys193, Arg204), and three troponin-T residues (Lys107, Lys125, Lys227). AGE modifications of three corresponding troponin-I residues (Lys58, Lys120, Lys194) and two corresponding troponin-T residues (Lys107, Lys227) were confirmed in cardiac tissue extracts from an experimental rodent diabetic model. Additionally, novel human troponin-I phosphorylation sites were detected (Thr119, Thr123). Accelerated AGE modification of troponin-C was evident in vitro with hexose sugar exposure. This study provides the first demonstration of the occurrence of cardiac troponin complex AGE-modifications. These irreversible AGE modifications are situated in regions of the troponin complex known to be important in myofilament relaxation, and may be of particular pathological importance in the pro-glycation environment of diabetic cardiomyopathy.
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Affiliation(s)
| | - Brendan Ma
- Department of Physiology, University of Melbourne, Melbourne, Australia
| | - Margaret A Brimble
- Department of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | - Jennifer E Van Eyk
- Advanced Clinical Biosystems Research Institute, Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, USA
| | - Lea M D Delbridge
- Department of Physiology, University of Melbourne, Melbourne, Australia
| | - Kimberley M Mellor
- Department of Physiology, University of Melbourne, Melbourne, Australia. .,Department of Physiology, University of Auckland, Auckland, New Zealand. .,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
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11
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Johnston JR, Chase PB, Pinto JR. Troponin through the looking-glass: emerging roles beyond regulation of striated muscle contraction. Oncotarget 2017; 9:1461-1482. [PMID: 29416706 PMCID: PMC5787451 DOI: 10.18632/oncotarget.22879] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 11/20/2017] [Indexed: 01/03/2023] Open
Abstract
Troponin is a heterotrimeric Ca2+-binding protein that has a well-established role in regulating striated muscle contraction. However, mounting evidence points to novel cellular functions of troponin, with profound implications in cancer, cardiomyopathy pathogenesis and skeletal muscle aging. Here, we highlight the non-canonical roles and aberrant expression patterns of troponin beyond the sarcomeric milieu. Utilizing bioinformatics tools and online databases, we also provide pathway, subcellular localization, and protein-protein/DNA interaction analyses that support a role for troponin in multiple subcellular compartments. This emerging knowledge challenges the conventional view of troponin as a sarcomere-specific protein exclusively involved in muscle contraction and may transform the way we think about sarcomeric proteins, particularly in the context of human disease and aging.
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Affiliation(s)
- Jamie R Johnston
- Department of Biomedical Sciences, The Florida State University College of Medicine, Tallahassee, FL, 32306-4300, USA
| | - P Bryant Chase
- Department of Biological Science, The Florida State University, Tallahassee, FL, 32306-4370, USA
| | - Jose Renato Pinto
- Department of Biomedical Sciences, The Florida State University College of Medicine, Tallahassee, FL, 32306-4300, USA
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12
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Tarnovskaya S, Kiselev A, Kostareva A, Frishman D. Structural consequences of mutations associated with idiopathic restrictive cardiomyopathy. Amino Acids 2017; 49:1815-1829. [DOI: 10.1007/s00726-017-2480-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 08/12/2017] [Indexed: 02/02/2023]
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13
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Sundarrajan L, Yeung C, Hahn L, Weber LP, Unniappan S. Irisin regulates cardiac physiology in zebrafish. PLoS One 2017; 12:e0181461. [PMID: 28771499 PMCID: PMC5542394 DOI: 10.1371/journal.pone.0181461] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 06/30/2017] [Indexed: 11/30/2022] Open
Abstract
Irisin is a myokine encoded in its precursor fibronectin type III domain containing 5 (FNDC5). It is abundantly expressed in cardiac and skeletal muscle, and is secreted upon the activation of peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1 alpha). We aimed to study the role of irisin on cardiac function and muscle protein regulation in zebrafish. Western blot analyses detected the presence of irisin protein (23 kDa) in zebrafish heart and skeletal muscle, and irisin immunoreactivity was detected in both tissues. Irisin siRNA treated samples did not show bands corresponding to irisin in zebrafish. In vitro studies found that treatment with irisin (0.1 nM) downregulated the expression of PGC-1 alpha, myostatin a, and b, while upregulating troponin C mRNA expression in zebrafish heart and skeletal muscle. Exogenous irisin (0.1 and 1 ng/g B.W) increased diastolic volume, heart rate and cardiac output, while knockdown of irisin (10 ng/g B.W) showed opposing effects on cardiovascular function. Irisin (1 and 10 ng/g B.W) downregulated PGC-1 alpha, myostatin a and b, and upregulated troponin C and troponin T2D mRNA expression. Meanwhile, knockdown of irisin showed opposing effects on troponin C, troponin T2D and myostatin a and b mRNAs in zebrafish heart and skeletal muscle. Collectively, these results identified muscle proteins as novel targets of irisin, and added irisin to the list of peptide modulators of cardiovascular physiology in zebrafish.
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Affiliation(s)
- Lakshminarasimhan Sundarrajan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Chanel Yeung
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Logan Hahn
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Lynn P. Weber
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- * E-mail:
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14
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England J, Loughna S, Rutland CS. Multiple Species Comparison of Cardiac Troponin T and Dystrophin: Unravelling the DNA behind Dilated Cardiomyopathy. J Cardiovasc Dev Dis 2017; 4:E8. [PMID: 29367539 PMCID: PMC5715711 DOI: 10.3390/jcdd4030008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/01/2017] [Accepted: 07/05/2017] [Indexed: 12/14/2022] Open
Abstract
Animals have frequently been used as models for human disorders and mutations. Following advances in genetic testing and treatment options, and the decreasing cost of these technologies in the clinic, mutations in both companion and commercial animals are now being investigated. A recent review highlighted the genes associated with both human and non-human dilated cardiomyopathy. Cardiac troponin T and dystrophin were observed to be associated with both human and turkey (troponin T) and canine (dystrophin) dilated cardiomyopathies. This review gives an overview of the work carried out in cardiac troponin T and dystrophin to date in both human and animal dilated cardiomyopathy.
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Affiliation(s)
- Jennifer England
- School of Life Sciences, Medical School, Queens Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Siobhan Loughna
- School of Life Sciences, Medical School, Queens Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Catrin Sian Rutland
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire LE12 5RD, UK.
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15
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Moldogazieva NT, Shaitan KV, Antonov MY, Mokhosoev IM, Levtsova OV, Terentiev AA. Human EGF-derived direct and reverse short linear motifs: conformational dynamics insight into the receptor-binding residues. J Biomol Struct Dyn 2017; 36:1286-1305. [PMID: 28447543 DOI: 10.1080/07391102.2017.1321502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Short linear motifs (SLiMs) have been recognized to perform diverse functions in a variety of regulatory proteins through the involvement in protein-protein interactions, signal transduction, cell cycle regulation, protein secretion, etc. However, detailed molecular mechanisms underlying their functions including roles of definite amino acid residues remain obscure. In our previous studies, we demonstrated that conformational dynamics of amino acid residues in oligopeptides derived from regulatory proteins such as alpha-fetoprotein (AFP), carcino-embryonic antigen (CEA), and pregnancy specific β1-glycoproteins (PSGs) contributes greatly to their biological activities. In the present work, we revealed the 22-member linear modules composed of direct and reverse AFP14-20-like heptapeptide motifs linked by CxxGY/FxGx consensus motif within epidermal growth factor (EGF), growth factors of EGF family and numerous regulatory proteins containing EGF-like modules. We showed, first, the existence of similarity in amino acid signatures of both direct and reverse motifs in terms of their physicochemical properties. Second, molecular dynamics (MD) simulation study demonstrated that key receptor-binding residues in human EGF in the aligned positions of the direct and reverse motifs may have similar distribution of conformational probability densities and dynamic behavior despite their distinct physicochemical properties. Third, we found that the length of a polypeptide chain (from 7 to 53 residues) has no effect, while disulfide bridging and backbone direction significantly influence the conformational distribution and dynamics of the residues. Our data may contribute to the atomic level structure-function analysis and protein structure decoding; additionally, they may provide a basis for novel protein/peptide engineering and peptide-mimetic drug design.
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Affiliation(s)
- Nurbubu T Moldogazieva
- a Department of Biochemistry and Molecular Biology , N.I. Pirogov Russian National Research Medical University , 1 Ostrovityanov str., Moscow 117997 , Russian Federation
| | - Konstantin V Shaitan
- b Faculty of Biology, Department of Bioengineering , M.V. Lomonosov Moscow State University , 1 Vorobyevy Gory, Moscow 119991 , Russian Federation
| | - Mikhail Yu Antonov
- c M.K. Ammosov North-Eastern Federal University , 58 Belinskiy str., Yakutsk 677980 , Republic of Sakha (Yakutia) , Russian Federation
| | - Innokenty M Mokhosoev
- a Department of Biochemistry and Molecular Biology , N.I. Pirogov Russian National Research Medical University , 1 Ostrovityanov str., Moscow 117997 , Russian Federation
| | - Olga V Levtsova
- b Faculty of Biology, Department of Bioengineering , M.V. Lomonosov Moscow State University , 1 Vorobyevy Gory, Moscow 119991 , Russian Federation
| | - Alexander A Terentiev
- a Department of Biochemistry and Molecular Biology , N.I. Pirogov Russian National Research Medical University , 1 Ostrovityanov str., Moscow 117997 , Russian Federation
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16
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Papadaki M, Marston SB. The Importance of Intrinsically Disordered Segments of Cardiac Troponin in Modulating Function by Phosphorylation and Disease-Causing Mutations. Front Physiol 2016; 7:508. [PMID: 27853436 PMCID: PMC5089987 DOI: 10.3389/fphys.2016.00508] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 10/17/2016] [Indexed: 11/18/2022] Open
Abstract
Troponin plays a central role in regulation of muscle contraction. It is the Ca2+ switch of striated muscles including the heart and in the cardiac muscle it is physiologically modulated by PKA-dependent phosphorylation at Ser22 and 23. Many cardiomyopathy-related mutations affect Ca2+ regulation and/or disrupt the relationship between Ca2+ binding and phosphorylation. Unlike the mechanism of heart activation, the modulation of Ca2+-sensitivity by phosphorylation of the cardiac specific N-terminal segment of TnI (1–30) is structurally subtle and has proven hard to investigate. The crystal structure of cardiac troponin describes only the relatively stable core of the molecule and the crucial mobile parts of the molecule are missing including TnI C-terminal region, TnI (1–30), TnI (134–149) (“inhibitory” peptide) and the C-terminal 28 amino acids of TnT that are intrinsically disordered. Recent studies have been performed to answer this matter by building structural models of cardiac troponin in phosphorylated and dephosphorylated states based on peptide NMR studies. Now these have been updated by more recent concepts derived from molecular dynamic simulations treating troponin as a dynamic structure. The emerging model confirms the stable core structure of troponin and the mobile structure of the intrinsically disordered segments. We will discuss how we can describe these segments in terms of dynamic transitions between a small number of states, with the probability distributions being altered by phosphorylation and by HCM or DCM-related mutations that can explain how Ca2+-sensitivity is modulated by phosphorylation and the effects of mutations.
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Affiliation(s)
- Maria Papadaki
- Department of Cell and Molecular Physiology, Loyola University of Chicago Maywood, IL, USA
| | - Steven B Marston
- Myocardial Function, National Heart and Lung Institute, Imperial College London London, UK
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Marques MDA, de Oliveira GAP. Cardiac Troponin and Tropomyosin: Structural and Cellular Perspectives to Unveil the Hypertrophic Cardiomyopathy Phenotype. Front Physiol 2016; 7:429. [PMID: 27721798 PMCID: PMC5033975 DOI: 10.3389/fphys.2016.00429] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 09/09/2016] [Indexed: 12/12/2022] Open
Abstract
Inherited myopathies affect both skeletal and cardiac muscle and are commonly associated with genetic dysfunctions, leading to the production of anomalous proteins. In cardiomyopathies, mutations frequently occur in sarcomeric genes, but the cause-effect scenario between genetic alterations and pathological processes remains elusive. Hypertrophic cardiomyopathy (HCM) was the first cardiac disease associated with a genetic background. Since the discovery of the first mutation in the β-myosin heavy chain, more than 1400 new mutations in 11 sarcomeric genes have been reported, awarding HCM the title of the “disease of the sarcomere.” The most common macroscopic phenotypes are left ventricle and interventricular septal thickening, but because the clinical profile of this disease is quite heterogeneous, these phenotypes are not suitable for an accurate diagnosis. The development of genomic approaches for clinical investigation allows for diagnostic progress and understanding at the molecular level. Meanwhile, the lack of accurate in vivo models to better comprehend the cellular events triggered by this pathology has become a challenge. Notwithstanding, the imbalance of Ca2+ concentrations, altered signaling pathways, induction of apoptotic factors, and heart remodeling leading to abnormal anatomy have already been reported. Of note, a misbalance of signaling biomolecules, such as kinases and tumor suppressors (e.g., Akt and p53), seems to participate in apoptotic and fibrotic events. In HCM, structural and cellular information about defective sarcomeric proteins and their altered interactome is emerging but still represents a bottleneck for developing new concepts in basic research and for future therapeutic interventions. This review focuses on the structural and cellular alterations triggered by HCM-causing mutations in troponin and tropomyosin proteins and how structural biology can aid in the discovery of new platforms for therapeutics. We highlight the importance of a better understanding of allosteric communications within these thin-filament proteins to decipher the HCM pathological state.
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Affiliation(s)
- Mayra de A Marques
- Programa de Biologia Estrutural, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Instituto de Bioquímica Médica Leopoldo de Meis, Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
| | - Guilherme A P de Oliveira
- Programa de Biologia Estrutural, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Instituto de Bioquímica Médica Leopoldo de Meis, Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
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