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Lambert MR, Gussoni E. Tropomyosin 3 (TPM3) function in skeletal muscle and in myopathy. Skelet Muscle 2023; 13:18. [PMID: 37936227 PMCID: PMC10629095 DOI: 10.1186/s13395-023-00327-x] [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: 08/11/2023] [Accepted: 10/10/2023] [Indexed: 11/09/2023] Open
Abstract
The tropomyosin genes (TPM1-4) contribute to the functional diversity of skeletal muscle fibers. Since its discovery in 1988, the TPM3 gene has been recognized as an indispensable regulator of muscle contraction in slow muscle fibers. Recent advances suggest that TPM3 isoforms hold more extensive functions during skeletal muscle development and in postnatal muscle. Additionally, mutations in the TPM3 gene have been associated with the features of congenital myopathies. The use of different in vitro and in vivo model systems has leveraged the discovery of several disease mechanisms associated with TPM3-related myopathy. Yet, the precise mechanisms by which TPM3 mutations lead to muscle dysfunction remain unclear. This review consolidates over three decades of research about the role of TPM3 in skeletal muscle. Overall, the progress made has led to a better understanding of the phenotypic spectrum in patients affected by mutations in this gene. The comprehensive body of work generated over these decades has also laid robust groundwork for capturing the multiple functions this protein plays in muscle fibers.
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Affiliation(s)
- Matthias R Lambert
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA.
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA.
| | - Emanuela Gussoni
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- The Stem Cell Program, Boston Children's Hospital, Boston, MA, 02115, USA
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Rall JA. Discovery of the regulatory role of calcium ion in muscle contraction and relaxation: Setsuro Ebashi and the international emergence of Japanese muscle research. ADVANCES IN PHYSIOLOGY EDUCATION 2022; 46:481-490. [PMID: 35759528 DOI: 10.1152/advan.00108.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 06/23/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
In the early 1950s Setsuro Ebashi was a graduate student at Tokyo University studying the biochemical models of muscle contraction. The muscle components in these models contracted in the presence of ATP, but what caught his attention was that the components did not relax when ATP was exhausted. Ebashi decided in 1952 to attempt to elucidate the mechanism of muscle relaxation using these models. This decision started a journey that would lead him to be the first to propose the calcium concept of muscle contraction and relaxation in 1961. It was an unpopular theory with biochemists who refused to accept that anything as simple as an inorganic ion, Ca2+, could control anything as important as muscle contraction. Ebashi was convinced that he was correct. He proceeded to show that micromolar concentrations of Ca2+ activated contraction. In 1961 he discovered the particulate nature of the ATP-dependent relaxing factor (the sarcoplasmic reticulum) and determined that it acted by binding Ca2+. Most notably, in 1966 he discovered troponin, the Ca2+ receptor in muscle, which mediated Ca2+ control of contraction. Ebashi's discoveries were considered the most important in the muscle field since the 1950s. Ebashi had to overcome the doubt of the scientific community. This story is one of great scientific achievement against great odds that marked the emergence of Japanese muscle research onto the international scientific stage.NEW & NOTEWORTHY Setsuro Ebashi proposed the calcium concept of muscle contraction and relaxation in 1961. It was a very unpopular theory. He showed that Ca2+ activated contraction and that the sarcoplasmic reticulum caused relaxation by binding Ca2+ in an ATP-dependent manner. Most notably, he discovered the receptor that mediated Ca2+ control of contraction and named it "troponin." Ebashi's discoveries are considered to be the most important in the muscle field since the 1950s.
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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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Tropomyosin Is Potential Markers for the Diagnosis and Prognosis of Bladder Cancer. DISEASE MARKERS 2022; 2022:6936262. [PMID: 35734544 PMCID: PMC9208974 DOI: 10.1155/2022/6936262] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/08/2022] [Accepted: 06/03/2022] [Indexed: 12/11/2022]
Abstract
Objective To investigate the correlation between tropomyosin (TM) and clinical characteristics of bladder cancer. In addition, the relationship between TM and immune cell infiltration in bladder cancer was further analyzed. Methods Based on The Cancer Genome Atlas (TCGA) database, the relationship between TM expression and clinicopathological features in bladder cancer was analyzed. Receiver operating characteristic (ROC) curve was used to evaluate the value of TM as a diagnostic marker for bladder cancer. Univariate and multivariate Cox regression was used to analyze the independent factors affecting the prognosis of patients with bladder cancer. The relationship between TM and immune cell infiltration was analyzed. Results ROC curve showed that TPM1, TPM2, and TPM3 had significant diagnostic ability (AUC was 0.845, 0.848, and 0.873, respectively). The high expression of TPM1 and TPM2 is associated with poor overall and disease-specific survival in patients with bladder cancer (P < 0.05). Multivariate Cox analysis showed that age and TPM1 were independent prognostic factors. The expression levels of TPM1, TPM2, TPM3, and TPM4 in low grade bladder cancer were lower than those in high grade bladder cancer (P < 0.05). TPM1 and TPM2 are positively correlated with the infiltration of macrophages and NK cells in bladder cancer. TPM3 is positively associated with Th2. TPM4 is positively correlated with Th1 cells, macrophages, and neutrophils (P < 0.05). Conclusions TPM1 and TPM2 are effective markers for the diagnosis of bladder cancer. TPM1 is an independent prognostic factor for bladder cancer. TM is also associated with the infiltration of various immune cells in bladder cancer. TM may have influenced the development of bladder cancer through immune inhibition.
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Hassoun R, Erdmann C, Schmitt S, Fujita-Becker S, Mügge A, Schröder RR, Geyer M, Borbor M, Jaquet K, Hamdani N, Mannherz HG. Functional Characterization of Cardiac Actin Mutants Causing Hypertrophic (p.A295S) and Dilated Cardiomyopathy (p.R312H and p.E361G). Int J Mol Sci 2022; 23:ijms23084465. [PMID: 35457283 PMCID: PMC9024677 DOI: 10.3390/ijms23084465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/15/2022] [Accepted: 04/15/2022] [Indexed: 11/16/2022] Open
Abstract
Human wild type (wt) cardiac α-actin and its mutants p.A295S or p.R312H and p.E361G correlated with hypertrophic or dilated cardiomyopathy, respectively, were expressed by using the baculovirus/Sf21 insect cell system. The c-actin variants inhibited DNase I, indicating maintenance of their native state. Electron microscopy showed the formation of normal appearing actin filaments though they showed mutant specific differences in length and straightness correlating with their polymerization rates. TRITC-phalloidin staining showed that p.A295S and p.R312H exhibited reduced and the p.E361G mutant increased lengths of their formed filaments. Decoration of c-actins with cardiac tropomyosin (cTm) and troponin (cTn) conveyed Ca2+-sensitivity of the myosin-S1 ATPase stimulation, which was higher for the HCM p.A295S mutant and lower for the DCM p.R312H and p.E361G mutants than for wt c-actin. The lower Ca2+-sensitivity of myosin-S1 stimulation by both DCM actin mutants was corrected by the addition of levosimendan. Ca2+-dependency of the movement of pyrene-labeled cTm along polymerized c-actin variants decorated with cTn corresponded to the relations observed for the myosin-S1 ATPase stimulation though shifted to lower Ca2+-concentrations. The N-terminal C0C2 domain of cardiac myosin-binding protein-C increased the Ca2+-sensitivity of the pyrene-cTM movement of bovine, recombinant wt, p.A295S, and p.E361G c-actins, but not of the p.R312H mutant, suggesting decreased affinity to cTm.
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Affiliation(s)
- Roua Hassoun
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Cardiology, St. Josef-Hospital, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany
| | - Constanze Erdmann
- Department of Anatomy and Molecular Embryology, Medical Faculty, Ruhr-University Bochum, D-44780 Bochum, Germany;
| | - Sebastian Schmitt
- Institute of Structural Biology, University of Bonn, D-53127 Bonn, Germany; (S.S.); (M.G.)
| | - Setsuko Fujita-Becker
- Cryoelectron Microscopy, BioQuant, Medical Faculty, University of Heidelberg, D-69120 Heidelberg, Germany; (S.F.-B.); (R.R.S.)
| | - Andreas Mügge
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Cardiology, St. Josef-Hospital, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany
| | - Rasmus R. Schröder
- Cryoelectron Microscopy, BioQuant, Medical Faculty, University of Heidelberg, D-69120 Heidelberg, Germany; (S.F.-B.); (R.R.S.)
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, D-53127 Bonn, Germany; (S.S.); (M.G.)
| | - Mina Borbor
- Department of Neurology, University Hospital Essen, D-45147 Essen, Germany;
| | - Kornelia Jaquet
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Cardiology, St. Josef-Hospital, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany
| | - Nazha Hamdani
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Cardiology, St. Josef-Hospital, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany
- Correspondence: (N.H.); (H.G.M.); Tel.: +49-234-32-29412 (N.H.); Fax: +49-234-32-14040 (N.H.); +49-234-32-14474 (H.G.M.)
| | - Hans Georg Mannherz
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Anatomy and Molecular Embryology, Medical Faculty, Ruhr-University Bochum, D-44780 Bochum, Germany;
- Correspondence: (N.H.); (H.G.M.); Tel.: +49-234-32-29412 (N.H.); Fax: +49-234-32-14040 (N.H.); +49-234-32-14474 (H.G.M.)
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Chan SF, Wen QQ, Ao CM, Wang W, Wang CG, Zhao YF. Transcriptome responses of RNAi-mediated ETH knockdown in Scylla paramamosain at different premolt substages. Front Endocrinol (Lausanne) 2022; 13:917088. [PMID: 35966071 PMCID: PMC9370559 DOI: 10.3389/fendo.2022.917088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 07/04/2022] [Indexed: 12/03/2022] Open
Abstract
Ecdysis triggering hormone (ETH) plays an important role in molting, reproduction, and courtship behavior in insects. To investigate the potential downstream pathways and genes of ETH in Scylla paramamosain, RNA interference (RNAi) was conducted on crabs at early (D0) and late (D2) premolt substages, and the transcriptome profiles of each group were compared by RNA sequencing. Real-time quantitative polymerase chain reaction (RT-qPCR) and semiquantitative polymerase chain reaction (RT-PCR) results showed a significant knockdown of ETH at D0 stage, whereas a significant increase was shown conversely in crabs at D2 substage after the injection of dsETH. A total of 242,979 transcripts were assembled, and 44,012 unigenes were identified. Transcriptomic comparison between crabs at D2 and D0 substages showed 2,683 differentially expressed genes (DEGs); these genes were enriched in ribosome and pathways related to transcription factor complex and cell part. Twenty DEGs were identified between dsETH-injected and dsGFP-injected crabs at D0 substage; these DEGs were involved in carbohydrate metabolism, one carbon pool by folate, and chitin binding. Twenty-six DEGs were identified between dsETH-injected and dsGFP-injected crabs at D2 substage; these DEGs were involved in calcium channel inhibitor activity, fat digestion and absorption, and cardiac muscle contraction. RT-qPCR verified the differential expression of the selected genes. In conclusion, crabs at D0 substage are more active in preparing the macromolecular complex that is needed for molting. Moreover, ETH has potential roles in carbohydrate metabolism, one carbon pool by folate, and chitin binding for crabs at D0 substage, while the role of ETH turns to be involved in calcium channel inhibitor activity, fat digestion and absorption, and cardiac muscle contraction at D2 substage to facilitate the occurrence of molting. The selected DEGs provide valuable insight into the role of ETH in the regulation of crustacean molting.
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Affiliation(s)
| | - Qi-Qiao Wen
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Chun-Mei Ao
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Wei Wang
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Beibu Gulf University, Qinzhou, China
| | - Cheng-Gui Wang
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Yan-Fei Zhao
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
- *Correspondence: Yan-Fei Zhao,
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De Novo Missense Mutations in TNNC1 and TNNI3 Causing Severe Infantile Cardiomyopathy Affect Myofilament Structure and Function and Are Modulated by Troponin Targeting Agents. Int J Mol Sci 2021; 22:ijms22179625. [PMID: 34502534 PMCID: PMC8431798 DOI: 10.3390/ijms22179625] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 01/09/2023] Open
Abstract
Rare pediatric non-compaction and restrictive cardiomyopathy are usually associated with a rapid and severe disease progression. While the non-compaction phenotype is characterized by structural defects and is correlated with systolic dysfunction, the restrictive phenotype exhibits diastolic dysfunction. The molecular mechanisms are poorly understood. Target genes encode among others, the cardiac troponin subunits forming the main regulatory protein complex of the thin filament for muscle contraction. Here, we compare the molecular effects of two infantile de novo point mutations in TNNC1 (p.cTnC-G34S) and TNNI3 (p.cTnI-D127Y) leading to severe non-compaction and restrictive phenotypes, respectively. We used skinned cardiomyocytes, skinned fibers, and reconstituted thin filaments to measure the impact of the mutations on contractile function. We investigated the interaction of these troponin variants with actin and their inter-subunit interactions, as well as the structural integrity of reconstituted thin filaments. Both mutations exhibited similar functional and structural impairments, though the patients developed different phenotypes. Furthermore, the protein quality control system was affected, as shown for TnC-G34S using patient's myocardial tissue samples. The two troponin targeting agents levosimendan and green tea extract (-)-epigallocatechin-3-gallate (EGCg) stabilized the structural integrity of reconstituted thin filaments and ameliorated contractile function in vitro in some, but not all, aspects to a similar degree for both mutations.
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Pavase TR, Lin H, Soomro MA, Zheng H, Li X, Wang K, Li Z. Visual detection of tropomyosin, a major shrimp allergenic protein using gold nanoparticles (AuNPs)-assisted colorimetric aptasensor. MARINE LIFE SCIENCE & TECHNOLOGY 2021; 3:382-394. [PMID: 37073291 PMCID: PMC10077205 DOI: 10.1007/s42995-020-00085-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 11/05/2020] [Indexed: 05/03/2023]
Abstract
A gold nanoparticle-based label-free colorimetric assay was developed to detect the shrimp allergenic protein tropomyosin (TM), an important biomarker responsible for severe clinical reactivity to shellfish. In a gold nanoparticles (AuNPs)-tropomyosin-binding aptamer (TMBA) complex, the aptamer adsorbs onto the surface of AuNPs and dissociates in the presence of TM. In addition, AuNPs tend to aggregate in the presence of ionic salt, revealing a color change (i.e., wine-red to purple/blue) with a shift in the maximum absorption peak from 520 nm. In the presence of specific binding TM, the aptamer folds into a tertiary structure where it more efficiently stabilizes AuNPs toward the salt-induced aggregation with a hypsochromic shift in the absorption spectra compared to the stabilized AuNPs by aptamer alone. Based on the aggregation and sensitive spectral transformation principle, the AuNPs-based colorimetric aptasensor was successfully applied to detect TM with a range of 10-200 nmol/L and a low detection limit of 40 nmol/L in water samples. The reliability, selectivity, and sensitivity of the aptasensor was then tested with food samples spiked with TM. The observed detection limit was as low as 70 nmol/L in shrimp, 90 nmol/L in tofu, and 80 nmol/L in eggs, respectively. We anticipate the proposed AuNPs-based colorimetric aptasensor assay possesses a high potential for the easy and efficient visual colorimetric detection of TM. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-020-00085-5.
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Affiliation(s)
- Tushar Ramesh Pavase
- Food Safety Laboratory, Department of Food Science and Engineering, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
| | - Hong Lin
- Food Safety Laboratory, Department of Food Science and Engineering, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
| | - Maqsood Ahmed Soomro
- Fish Molecular Immunology Laboratory, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
| | - Hongwei Zheng
- Food Safety Laboratory, Department of Food Science and Engineering, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
| | - Xiaxia Li
- Food Safety Laboratory, Department of Food Science and Engineering, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
| | - Kexin Wang
- Food Safety Laboratory, Department of Food Science and Engineering, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
| | - Zhenxing Li
- Food Safety Laboratory, Department of Food Science and Engineering, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003 China
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Cao J, Routh AL, Kuyumcu-Martinez MN. Nanopore sequencing reveals full-length Tropomyosin 1 isoforms and their regulation by RNA-binding proteins during rat heart development. J Cell Mol Med 2021; 25:8352-8362. [PMID: 34302435 PMCID: PMC8419188 DOI: 10.1111/jcmm.16795] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/01/2021] [Accepted: 07/06/2021] [Indexed: 12/11/2022] Open
Abstract
Alternative splicing (AS) contributes to the diversity of the proteome by producing multiple isoforms from a single gene. Although short‐read RNA‐sequencing methods have been the gold standard for determining AS patterns of genes, they have a difficulty in defining full‐length mRNA isoforms assembled using different exon combinations. Tropomyosin 1 (TPM1) is an actin‐binding protein required for cytoskeletal functions in non‐muscle cells and for contraction in muscle cells. Tpm1 undergoes AS regulation to generate muscle versus non‐muscle TPM1 protein isoforms with distinct physiological functions. It is unclear which full‐length Tpm1 isoforms are produced via AS and how they are regulated during heart development. To address these, we utilized nanopore long‐read cDNA sequencing without gene‐specific PCR amplification. In rat hearts, we identified full‐length Tpm1 isoforms composed of distinct exons with specific exon linkages. We showed that Tpm1 undergoes AS transitions during embryonic heart development such that muscle‐specific exons are connected generating predominantly muscle‐specific Tpm1 isoforms in adult hearts. We found that the RNA‐binding protein RBFOX2 controls AS of rat Tpm1 exon 6a, which is important for cooperative actin binding. Furthermore, RBFOX2 regulates Tpm1 AS of exon 6a antagonistically to the RNA‐binding protein PTBP1. In sum, we defined full‐length Tpm1 isoforms with different exon combinations that are tightly regulated during cardiac development and provided insights into the regulation of Tpm1 AS by RNA‐binding proteins. Our results demonstrate that nanopore sequencing is an excellent tool to determine full‐length AS variants of muscle‐enriched genes.
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Affiliation(s)
- Jun Cao
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Andrew L Routh
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA.,Sealy Centre for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Muge N Kuyumcu-Martinez
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA.,Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA.,Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch, Galveston, Texas, USA
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Racca AW, Rynkiewicz MJ, LaFave N, Ghosh A, Lehman W, Moore JR. M8R tropomyosin mutation disrupts actin binding and filament regulation: The beginning affects the middle and end. J Biol Chem 2020; 295:17128-17137. [PMID: 33020181 PMCID: PMC7863880 DOI: 10.1074/jbc.ra120.014713] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/28/2020] [Indexed: 11/06/2022] Open
Abstract
Dilated cardiomyopathy (DCM) is associated with mutations in cardiomyocyte sarcomeric proteins, including α-tropomyosin. In conjunction with troponin, tropomyosin shifts to regulate actomyosin interactions. Tropomyosin molecules overlap via tropomyosin-tropomyosin head-to-tail associations, forming a continuous strand along the thin filament. These associations are critical for propagation of tropomyosin's reconfiguration along the thin filament and key for the cooperative switching between heart muscle contraction and relaxation. Here, we tested perturbations in tropomyosin structure, biochemistry, and function caused by the DCM-linked mutation, M8R, which is located at the overlap junction. Localized and nonlocalized structural effects of the mutation were found in tropomyosin that ultimately perturb its thin filament regulatory function. Comparison of mutant and WT α-tropomyosin was carried out using in vitro motility assays, CD, actin co-sedimentation, and molecular dynamics simulations. Regulated thin filament velocity measurements showed that the presence of M8R tropomyosin decreased calcium sensitivity and thin filament cooperativity. The co-sedimentation of actin and tropomyosin showed weakening of actin-mutant tropomyosin binding. The binding of troponin T's N terminus to the actin-mutant tropomyosin complex was also weakened. CD and molecular dynamics indicate that the M8R mutation disrupts the four-helix bundle at the head-to-tail junction, leading to weaker tropomyosin-tropomyosin binding and weaker tropomyosin-actin binding. Molecular dynamics revealed that altered end-to-end bond formation has effects extending toward the central region of the tropomyosin molecule, which alter the azimuthal position of tropomyosin, likely disrupting the mutant thin filament response to calcium. These results demonstrate that mutation-induced alterations in tropomyosin-thin filament interactions underlie the altered regulatory phenotype and ultimately the pathogenesis of DCM.
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Affiliation(s)
- Alice Ward Racca
- Department of Biological Sciences, University of Massachusetts-Lowell, Lowell, Massachusetts, USA
| | - Michael J Rynkiewicz
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Nicholas LaFave
- Department of Biological Sciences, University of Massachusetts-Lowell, Lowell, Massachusetts, USA
| | - Anita Ghosh
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, Massachusetts, USA
| | - William Lehman
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Jeffrey R Moore
- Department of Biological Sciences, University of Massachusetts-Lowell, Lowell, Massachusetts, USA.
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Dima JB, Sequeiros C, Barón P, Zaritzky N. Biochemical Composition and Quality Parameters of Raw and Cooked Refrigerated Patagonian Crabmeat (Ovalipes trimaculatus). JOURNAL OF AQUATIC FOOD PRODUCT TECHNOLOGY 2020. [DOI: 10.1080/10498850.2020.1828524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Jimena Bernadette Dima
- Instituto de Biología de Organismos Marinos (IBIOMAR CCT CONICET- CENPAT), Chubut, Argentina
- Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA -CONICET- UNLP), Fac. Cs. Exactas, UNLP, Buenos Aires, Argentina
| | - Cynthia Sequeiros
- Centro Para el Estudio de Sistemas Marinos (CESIMAR CCT CONICET- CENPAT), Chubut, Argentina
| | - Pedro Barón
- Centro Para el Estudio de Sistemas Marinos (CESIMAR CCT CONICET- CENPAT), Chubut, Argentina
| | - Noemi Zaritzky
- Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA -CONICET- UNLP), Fac. Cs. Exactas, UNLP, Buenos Aires, Argentina
- Facultad de Ingeniería (UNLP), Departamento de Ingeniería Química, La Plata, Argentina
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11
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IgE reactivity to fish allergens from Pacific cod (Gadus macrocephalus) in atopic dogs. BMC Vet Res 2020; 16:341. [PMID: 32938440 PMCID: PMC7493343 DOI: 10.1186/s12917-020-02559-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 09/07/2020] [Indexed: 11/24/2022] Open
Abstract
Background IgE reactivity to fish allergens in atopic dogs, which are used as models for food allergy, has not been elucidated to date. We investigated IgE reactivity to crude extracts and purified allergens derived from the Pacific cod (Gadus macrocephalus) in atopic dogs to identify the allergenic proteins of cod. Results The levels of specific IgE to crude cod extracts were measured in the sera of 179 atopic dogs, including 27 dogs with cod allergy, using enzyme-linked immunosorbent assay (ELISA). Specific IgE to crude cod extracts were present in 36 (20%) of the 179 atopic dogs and in 12 (44%) of the 27 dogs with cod allergy. The allergens in crude cod extracts were analyzed by ELISA, immunoblotting, and liquid chromatography-tandem mass spectrometry. In allergen component analysis, IgE reactivity to tropomyosin and enolase was observed in the sera of dogs with cod allergy. IgE reactivity to parvalbumin, collagen, and tropomyosin was evaluated using the sera of atopic dogs that tested positive for specific IgE to crude cod extracts. Among the 36 dogs with IgE reactivity to crude cod extracts, 9 (25%), 14 (39%), and 18 (50%) dogs tested positive for specific IgE to parvalbumin, collagen, and tropomyosin, respectively. Conclusions The IgE reactivity to cod allergens observed in dogs was similar to that in humans, and this finding further supports the use of atopic dogs with fish allergy as a model for fish allergy in humans.
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Dube DK, Dube S, Abbott L, Elsekaily O, Sanger JW, Sanger JM, Poiesz BJ. Sarcomeric TPM3 expression in human heart and skeletal muscle. Cytoskeleton (Hoboken) 2020; 77:313-328. [PMID: 32761805 DOI: 10.1002/cm.21629] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 01/28/2023]
Abstract
In mammals, four tropomyosin genes TPM1, TPM2, TPM3, and TPM4 are known. One isoform of the TPM3 gene, encoding 285 amino acid residues designated as TPM3α, has been reported. TPM3α protein expression in human hearts is not definitively established. We have cloned from human heart and skeletal muscle transcripts of TPM3α and three novel TPM3 isoforms, TPM3ν, TPM3ξ, and TPM3ο. TPM3ν and TPM3ο are alternatively spliced RNAs with different 3'-UTRs encoding an identical novel protein with 285 amino acid differing from TPM3α and TPM3ξ in exon 6 only. TPM3α and TPM3ξ, which have different 3'UTRs, also encode an identical protein. qRT-PCR data show that the transcripts of TPM3α, TPM3ν, TPM3ξ, and TPM3ο are expressed in both heart and skeletal muscle. We have evaluated the expression of various TPM proteins in fetal and adult human hearts, and also in skeletal muscle samples. Western blots using CG3 antibody show a stronger signal of TPM3 protein in fetal heart and adult skeletal muscle compared to adult heart. LC-MS/MS studies with the protein spots separated and identified by CH1 antibody after 2D Western blot analyses, confirm the expression of TPM3α/TPM3ξ in heart, but some peptides detected could be either TPM3α or TPM3ν. In heart samples, TPM1 protein was the dominant with varying amount of TPM2 and TPM3, while TPM4 expression was not observed. In skeletal muscles, TPM2 was the majority TPM protein expressed. The biological consequences of these varying expression of individual tropomyosin proteins are yet to be established.
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Affiliation(s)
- Dipak K Dube
- Department of Medicine, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Syamalima Dube
- Department of Medicine, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Lynn Abbott
- Department of Medicine, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Omar Elsekaily
- Department of Medicine, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Joseph W Sanger
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Jean M Sanger
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Bernard J Poiesz
- Department of Medicine, SUNY Upstate Medical University, Syracuse, New York, USA
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13
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Sano KI, Yuki T, Nomata Y, Nakayama N, Iida R, Mitomo H, Ijiro K, Osada Y. Intrahelical Interactions in an α-Helical Coiled Coil Determine the Structural Stability of Tropomyosin. Biochemistry 2020; 59:2194-2202. [DOI: 10.1021/acs.biochem.0c00203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Ken-Ichi Sano
- Department of Applied Chemistry, Faculty of Fundamental Engineering, Nippon Institute of Technology, Miyashiro, Saitama 345-8501, Japan
- Graduate School of Environmental Symbiotic System Major, Nippon Institute of Technology, Miyashiro, Saitama 345-8501, Japan
| | - Tsubasa Yuki
- Graduate School of Environmental Symbiotic System Major, Nippon Institute of Technology, Miyashiro, Saitama 345-8501, Japan
| | - Yuta Nomata
- Graduate School of Environmental Symbiotic System Major, Nippon Institute of Technology, Miyashiro, Saitama 345-8501, Japan
| | - Norihisa Nakayama
- Graduate School of Environmental Symbiotic System Major, Nippon Institute of Technology, Miyashiro, Saitama 345-8501, Japan
| | - Ryo Iida
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Hideyuki Mitomo
- Research Institute for Electronic Science and Global Station for Soft Matter, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo 001-0021, Japan
| | - Kuniharu Ijiro
- Research Institute for Electronic Science and Global Station for Soft Matter, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo 001-0021, Japan
| | - Yoshihito Osada
- Nano Medical Engineering Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
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14
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Cimiotti D, Fujita-Becker S, Möhner D, Smolina N, Budde H, Wies A, Morgenstern L, Gudkova A, Sejersen T, Sjöberg G, Mügge A, Nowaczyk MM, Reusch P, Pfitzer G, Stehle R, Schröder RR, Mannherz HG, Kostareva A, Jaquet K. Infantile restrictive cardiomyopathy: cTnI-R170G/W impair the interplay of sarcomeric proteins and the integrity of thin filaments. PLoS One 2020; 15:e0229227. [PMID: 32182250 PMCID: PMC7077804 DOI: 10.1371/journal.pone.0229227] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 01/31/2020] [Indexed: 12/11/2022] Open
Abstract
TNNI3 encoding cTnI, the inhibitory subunit of the troponin complex, is the main target for mutations leading to restrictive cardiomyopathy (RCM). Here we investigate two cTnI-R170G/W amino acid replacements, identified in infantile RCM patients, which are located in the regulatory C-terminus of cTnI. The C-terminus is thought to modulate the function of the inhibitory region of cTnI. Both cTnI-R170G/W strongly enhanced the Ca2+-sensitivity of skinned fibres, as is typical for RCM-mutations. Both mutants strongly enhanced the affinity of troponin (cTn) to tropomyosin compared to wildtype cTn, whereas binding to actin was either strengthened (R170G) or weakened (R170W). Furthermore, the stability of reconstituted thin filaments was reduced as revealed by electron microscopy. Filaments containing R170G/W appeared wavy and showed breaks. Decoration of filaments with myosin subfragment S1 was normal in the presence of R170W, but was irregular with R170G. Surprisingly, both mutants did not affect the Ca2+-dependent activation of reconstituted cardiac thin filaments. In the presence of the N-terminal fragment of cardiac myosin binding protein C (cMyBPC-C0C2) cooperativity of thin filament activation was increased only when the filaments contained wildtype cTn. No effect was observed in the presence of cTn containing R170G/W. cMyBPC-C0C2 significantly reduced binding of wildtype troponin to actin/tropomyosin, but not of both mutant cTn. Moreover, we found a direct troponin/cMyBPC-C0C2 interaction using microscale thermophoresis and identified cTnI and cTnT, but not cTnC as binding partners for cMyBPC-C0C2. Only cTn containing cTnI-R170G showed a reduced affinity towards cMyBPC-C0C2. Our results suggest that the RCM cTnI variants R170G/W impair the communication between thin and thick filament proteins and destabilize thin filaments.
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Affiliation(s)
- Diana Cimiotti
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
| | - Setsuko Fujita-Becker
- Cryoelectron Microscopy, BioQuant, Medical Faculty, University of Heidelberg, Heidelberg, Germany
| | - Desirée Möhner
- Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Natalia Smolina
- Department of Molecular Biology and Genetics, Almazov Federal Medical Research Center, St. Petersburg, Russia
| | - Heidi Budde
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
| | - Aline Wies
- Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Lisa Morgenstern
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
| | - Alexandra Gudkova
- Department of Molecular Biology and Genetics, Almazov Federal Medical Research Center, St. Petersburg, Russia
| | - Thomas Sejersen
- Department of Women's and Children's Health and Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Gunnar Sjöberg
- Department of Women's and Children's Health and Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Andreas Mügge
- Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
| | - Marc M Nowaczyk
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Peter Reusch
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany
| | | | - Robert Stehle
- Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Rasmus R Schröder
- Cryoelectron Microscopy, BioQuant, Medical Faculty, University of Heidelberg, Heidelberg, Germany
| | - Hans G Mannherz
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Department of Anatomy and Embryology, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
| | - Anna Kostareva
- Department of Molecular Biology and Genetics, Almazov Federal Medical Research Center, St. Petersburg, Russia.,Department of Women's and Children's Health and Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Kornelia Jaquet
- Department of Clinical Pharmacology and Molecular Cardiology, Ruhr-University of Bochum, Bochum, Germany.,Cardiology, Bergmannsheil and St. Josef Hospital, Clinics of the Ruhr-University Bochum, Bochum, Germany
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15
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Xu LL, Lin H, Li ZX, Ahmed I, Pramod S, Lin H, Lv LT, Tian SL, Yu ZW. Influence of nonthermal extraction technique and allergenicity characteristics of tropomyosin from fish (Larimichthys crocea) in comparison with shrimp (Litopenaeus vannamei) and clam (Ruditapes philippinarum). Food Chem 2020; 309:125575. [DOI: 10.1016/j.foodchem.2019.125575] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/16/2019] [Accepted: 09/20/2019] [Indexed: 02/09/2023]
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16
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Lehman W, Rynkiewicz MJ, Moore JR. A new twist on tropomyosin binding to actin filaments: perspectives on thin filament function, assembly and biomechanics. J Muscle Res Cell Motil 2020; 41:23-38. [PMID: 30771202 PMCID: PMC6697252 DOI: 10.1007/s10974-019-09501-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 02/07/2019] [Indexed: 02/07/2023]
Abstract
Tropomyosin, best known for its role in the steric regulation of muscle contraction, polymerizes head-to-tail to form cables localized along the length of both muscle and non-muscle actin-based thin filaments. In skeletal and cardiac muscles, tropomyosin, under the control of troponin and myosin, moves in a cooperative manner between blocked, closed and open positions on filaments, thereby masking and exposing actin-binding sites necessary for myosin crossbridge head interactions. While the coiled-coil signature of tropomyosin appears to be simple, closer inspection reveals surprising structural complexity required to perform its role in steric regulation. For example, component α-helices of coiled coils are typically zippered together along a continuous core hydrophobic stripe. Tropomyosin, however, contains a number of anomalous, functionally controversial, core amino acid residues. We argue that the atypical residues at this interface, including clusters of alanines and a charged aspartate, are required for preshaping tropomyosin to readily fit to the surface of the actin filament, but do so without compromising tropomyosin rigidity once the filament is assembled. Indeed, persistence length measurements of tropomyosin are characteristic of a semi-rigid cable, in this case conducive to cooperative movement on thin filaments. In addition, we also maintain that tropomyosin displays largely unrecognized and residue-specific torsional variance, which is involved in optimizing contacts between actin and tropomyosin on the assembled thin filament. Corresponding twist-induced stiffness may also enhance cooperative translocation of tropomyosin across actin filaments. We conclude that anomalous core residues of tropomyosin facilitate thin filament regulatory behavior in a multifaceted way.
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Affiliation(s)
- William Lehman
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, Massachusetts, U.S.A
| | - Michael J. Rynkiewicz
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, Massachusetts, U.S.A
| | - Jeffrey R. Moore
- Department of Biological Sciences, University of Massachusetts-Lowell, Lowell, Massachusetts, U.S.A
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17
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Development of ELISA Method for Detecting Crustacean Major Allergen Tropomyosin in Processed Food Samples. FOOD ANAL METHOD 2019. [DOI: 10.1007/s12161-019-01627-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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18
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Huang MC, Lee CL, Ochiai Y, Watabe S. Thermostability of tropomyosins from the fast skeletal muscles of tropical fish species. FISH PHYSIOLOGY AND BIOCHEMISTRY 2019; 45:1189-1202. [PMID: 30945041 DOI: 10.1007/s10695-019-00632-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 03/10/2019] [Indexed: 06/09/2023]
Abstract
In order to investigate the species-specific heat tolerance of tropical fishes, the thermodynamic properties of muscle tropomyosin, a member of myofibrillar proteins, were compared among milkfish, tilapia, grouper, and mudskipper. The purified tropomyosins were subjected to differential scanning calorimetry and circular dichroism spectrometry. To unveil the relationship between the stability and the amino acid sequences, the muscle tropomyosin genes of the four species were also cloned, and their deduced amino acid sequences were compared. Thermodynamic analysis revealed that the milkfish tropomyosin showed lower refolding ability after thermal denaturation, compared with those of the other species. The amino acid sequences of these tropomyosins were similar to each other, with the identity being in the range of 95-96%.
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Affiliation(s)
- Ming-Chih Huang
- Department of Biological Sciences and Technology, National University of Tainan, 33, Sec.2, Shu-Lin St., Tainan, Taiwan, 700-05, Republic of China.
| | - Cheng-Linn Lee
- Department of Biological Sciences and Technology, National University of Tainan, 33, Sec.2, Shu-Lin St., Tainan, Taiwan, 700-05, Republic of China
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Bunkyo, 113-8657, Japan
| | - Yoshihiro Ochiai
- Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi, 980-0845, Japan
| | - Shugo Watabe
- Kitasato University School of Marine Biosciences, Sagamihara, Kanagawa, 252-0374, Japan
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19
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Humayun-Zakaria N, Arnold R, Goel A, Ward D, Savill S, Bryan RT. Tropomyosins: Potential Biomarkers for Urothelial Bladder Cancer. Int J Mol Sci 2019; 20:E1102. [PMID: 30836651 PMCID: PMC6429115 DOI: 10.3390/ijms20051102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 02/07/2023] Open
Abstract
Despite the incidence and prevalence of urothelial bladder cancer (UBC), few advances in treatment and diagnosis have been made in recent years. In this review, we discuss potential biomarker candidates: the tropomyosin family of genes, encoded by four loci in the human genome. The expression of these genes is tissue-specific. Tropomyosins are responsible for diverse cellular roles, most notably based upon their interplay with actin to maintain cellular processes, integrity and structure. Tropomyosins exhibit a large variety of splice forms, and altered isoform expression levels have been associated with cancer, including UBC. Notably, tropomyosin isoforms are detectable in urine, offering the potential for non-invasive diagnosis and risk-stratification. This review collates the basic knowledge on tropomyosin and its isoforms, and discusses their relationships with cancer-related phenomena, most specifically in UBC.
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Affiliation(s)
- Nada Humayun-Zakaria
- Institute of Cancer and Genomic Sciences, College of Medicine and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| | - Roland Arnold
- Institute of Cancer and Genomic Sciences, College of Medicine and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| | - Anshita Goel
- Institute of Cancer and Genomic Sciences, College of Medicine and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| | - Douglas Ward
- Institute of Cancer and Genomic Sciences, College of Medicine and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| | - Stuart Savill
- North Wales Clinical Research Centre, Betsi Cadwaladr University Health Board, Wrexham LL13 7YP, UK.
| | - Richard T Bryan
- Institute of Cancer and Genomic Sciences, College of Medicine and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
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20
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Abstract
Tropomyosin is the archetypal-coiled coil, yet studies of its structure and function have proven it to be a dynamic regulator of actin filament function in muscle and non-muscle cells. Here we review aspects of its structure that deviate from canonical leucine zipper coiled coils that allow tropomyosin to bind to actin, regulate myosin, and interact directly and indirectly with actin-binding proteins. Four genes encode tropomyosins in vertebrates, with additional diversity that results from alternate promoters and alternatively spliced exons. At the same time that periodic motifs for binding actin and regulating myosin are conserved, isoform-specific domains allow for specific interaction with myosins and actin filament regulatory proteins, including troponin. Tropomyosin can be viewed as a universal regulator of the actin cytoskeleton that specifies actin filaments for cellular and intracellular functions.
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21
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Toyota N, Fujitsuka C, Ishibashi G, S Yoshida L, Takano-Ohmuro H. Morphological Modifications in Myofibrils by Suppressing Tropomyosin 4α in Chicken Cardiac Myocytes. Cell Struct Funct 2016; 41:45-54. [PMID: 27118431 DOI: 10.1247/csf.15007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Tropomyosin (TPM) localizes along F-actin and, together with troponin T (TnT) and other components, controls calcium-sensitive muscle contraction. The role of the TPM isoform (TPM4α) that is expressed in embryonic and adult cardiac muscle cells in chicken is poorly understood. To analyze the function of TPM4α in myofibrils, the effects of TPM4α-suppression were examined in embryonic cardiomyocytes by small interference RNA transfection. Localization of myofibril proteins such as TPM, actin, TnT, α-actinin, myosin and connectin was examined by immunofluorescence microscopy on day 5 when almost complete TPM4α-suppression occurred in culture. A unique large structure was detected, consisting of an actin aggregate bulging from the actin bundle, and many curved filaments projecting from the aggregate. TPM, TnT and actin were detected on the large structure, but myosin, connectin, α-actinin and obvious myofibril striations were undetectable. It is possible that TPM4α-suppressed actin filaments are sorted and excluded at the place of the large structure. This suggests that TPM4α-suppression significantly affects actin filament, and that TPM4α plays an important role in constructing and maintaining sarcomeres and myofibrils in cardiac muscle.
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Affiliation(s)
- Naoji Toyota
- Department of Environmental Biology, Kumamoto Gakuen University
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22
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Jin Y, Peng Y, Lin Z, Chen YC, Wei L, Hacker TA, Larsson L, Ge Y. Comprehensive analysis of tropomyosin isoforms in skeletal muscles by top-down proteomics. J Muscle Res Cell Motil 2016; 37:41-52. [PMID: 27090236 PMCID: PMC4955698 DOI: 10.1007/s10974-016-9443-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/07/2016] [Indexed: 01/09/2023]
Abstract
Mammalian skeletal muscles are heterogeneous in nature and are capable of performing various functions. Tropomyosin (Tpm) is a major component of the thin filament in skeletal muscles and plays an important role in controlling muscle contraction and relaxation. Tpm is known to consist of multiple isoforms resulting from different encoding genes and alternative splicing, along with post-translational modifications. However, a systematic characterization of Tpm isoforms in skeletal muscles is still lacking. Therefore, we employed top-down mass spectrometry (MS) to identify and characterize Tpm isoforms present in different skeletal muscles from multiple species, including swine, rat, and human. Our study revealed that Tpm1.1 and Tpm2.2 are the two major Tpm isoforms in swine and rat skeletal muscles, whereas Tpm1.1, Tpm2.2, and Tpm3.12 are present in human skeletal muscles. Tandem MS was utilized to identify the sequences of the major Tpm isoforms. Furthermore, quantitative analysis revealed muscle-type specific differences in the abundance of un-modified and modified Tpm isoforms in rat and human skeletal muscles. This study represents the first systematic investigation of Tpm isoforms in skeletal muscles, which not only demonstrates the capabilities of top-down MS for the comprehensive characterization of skeletal myofilament proteins but also provides the basis for further studies on these Tpm isoforms in muscle-related diseases.
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Affiliation(s)
- Yutong Jin
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI, 53706, USA
| | - Ying Peng
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA
- Human Proteomics Program, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA
| | - Ziqing Lin
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA
- Human Proteomics Program, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA
| | - Yi-Chen Chen
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI, 53706, USA
| | - Liming Wei
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, P.R. China
| | - Timothy A Hacker
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA
| | - Lars Larsson
- Department of Physiology and Pharmacology, Department of Clinical Neuroscience, Clinical Neurophysiology Section, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI, 53706, USA.
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA.
- Human Proteomics Program, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA.
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23
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Abstract
By interacting with the troponin-tropomyosin complex on myofibrillar thin filaments, Ca2+ and myosin govern the regulatory switching processes influencing contractile activity of mammalian cardiac and skeletal muscles. A possible explanation of the roles played by Ca2+ and myosin emerged in the early 1970s when a compelling "steric model" began to gain traction as a likely mechanism accounting for muscle regulation. In its most simple form, the model holds that, under the control of Ca2+ binding to troponin and myosin binding to actin, tropomyosin strands running along thin filaments either block myosin-binding sites on actin when muscles are relaxed or move away from them when muscles are activated. Evidence for the steric model was initially based on interpretation of subtle changes observed in X-ray fiber diffraction patterns of intact skeletal muscle preparations. Over the past 25 years, electron microscopy coupled with three-dimensional reconstruction directly resolved thin filament organization under many experimental conditions and at increasingly higher resolution. At low-Ca2+, tropomyosin was shown to occupy a "blocked-state" position on the filament, and switched-on in a two-step process, involving first a movement of tropomyosin away from the majority of the myosin-binding site as Ca2+ binds to troponin and then a further movement to fully expose the site when small numbers of myosin heads bind to actin. In this contribution, basic information on Ca2+-regulation of muscle contraction is provided. A description is then given relating the voyage of discovery taken to arrive at the present understanding of the steric regulatory model.
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Affiliation(s)
- William Lehman
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, Massachusetts, U.S.A
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24
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Sequeira V, van der Velden J. Historical perspective on heart function: the Frank-Starling Law. Biophys Rev 2015; 7:421-447. [PMID: 28510104 DOI: 10.1007/s12551-015-0184-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 12/18/2022] Open
Abstract
More than a century of research on the Frank-Starling Law has significantly advanced our knowledge about the working heart. The Frank-Starling Law mandates that the heart is able to match cardiac ejection to the dynamic changes occurring in ventricular filling and thereby regulates ventricular contraction and ejection. Significant efforts have been attempted to identify a common fundamental basis for the Frank-Starling heart and, although a unifying idea has still to come forth, there is mounting evidence of a direct relationship between length changes in individual constituents (cardiomyocytes) and their sensitivity to Ca2+ ions. As the Frank-Starling Law is a vital event for the healthy heart, it is of utmost importance to understand its mechanical basis in order to optimize and organize therapeutic strategies to rescue the failing human heart. The present review is a historic perspective on cardiac muscle function. We "revive" a century of scientific research on the heart's fundamental protein constituents (contractile proteins), to their assemblies in the muscle (the sarcomeres), culminating in a thorough overview of the several synergistically events that compose the Frank-Starling mechanism. It is the authors' personal beliefs that much can be gained by understanding the Frank-Starling relationship at the cellular and whole organ level, so that we can finally, in this century, tackle the pathophysiologic mechanisms underlying heart failure.
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Affiliation(s)
- Vasco Sequeira
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
| | - Jolanda van der Velden
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.,ICIN- Netherlands Heart Institute, Utrecht, The Netherlands
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25
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Fudge KR, Heeley DH. Biochemical Characterization of the Roles of Glycines 24 and 27 and Threonine 179 in Tropomyosin from the Fast Skeletal Trunk Muscle of the Atlantic Salmon. Biochemistry 2015; 54:2769-76. [DOI: 10.1021/acs.biochem.5b00156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Korrina R. Fudge
- Department
of Biochemistry, Memorial University of Newfoundland, St. John’s, Newfoundland A1B 3X9, Canada
| | - David H. Heeley
- Department
of Biochemistry, Memorial University of Newfoundland, St. John’s, Newfoundland A1B 3X9, Canada
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26
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Kulkarni AD, Kiron V, Rombout JHWM, Brinchmann MF, Fernandes JMO, Sudheer NS, Singh BIS. Protein profiling in the gut of Penaeus monodon gavaged with oral WSSV-vaccines and live white spot syndrome virus. Proteomics 2014; 14:1660-73. [PMID: 24782450 DOI: 10.1002/pmic.201300405] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 03/23/2014] [Accepted: 04/25/2014] [Indexed: 11/12/2022]
Abstract
White spot syndrome virus (WSSV) is a pathogen that causes considerable mortality of the farmed shrimp, Penaeus monodon. Candidate 'vaccines', WSSV envelope protein VP28 and formalin-inactivated WSSV, can provide short-lived protection against the virus. In this study, P. monodon was orally intubated with the aforementioned vaccine candidates, and protein expression in the gut of immunised shrimps was profiled. The alterations in protein profiles in shrimps infected orally with live-WSSV were also examined. Seventeen of the identified proteins in the vaccine and WSSV-intubated shrimps varied significantly compared to those in the control shrimps. These proteins, classified under exoskeletal, cytoskeletal, immune-related, intracellular organelle part, intracellular calcium-binding or energy metabolism, are thought to directly or indirectly affect shrimp's immunity. The changes in the expression levels of crustacyanin, serine proteases, myosin light chain, and ER protein 57 observed in orally vaccinated shrimp may probably be linked to immunoprotective responses. On the other hand, altered expression of proteins linked to exoskeleton, calcium regulation and energy metabolism in WSSV-intubated shrimps is likely to symbolise disturbances in calcium homeostasis and energy metabolism.
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Affiliation(s)
- Amod D Kulkarni
- Faculty of Biosciences and Aquaculture, University of Nordland, Bodø, Norway
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27
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Kirwan JP, Hodges RS. Transmission of stability information through the N-domain of tropomyosin is interrupted by a stabilizing mutation (A109L) in the hydrophobic core of the stability control region (residues 97-118). J Biol Chem 2013; 289:4356-66. [PMID: 24362038 PMCID: PMC3924298 DOI: 10.1074/jbc.m113.507236] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Tropomyosin (Tm) is an actin-binding, thin filament, two-stranded α-helical coiled-coil critical for muscle contraction and cytoskeletal function. We made the first identification of a stability control region (SCR), residues 97-118, in the Tm sequence that controls overall protein stability but is not required for folding. We also showed that the individual α-helical strands of the coiled-coil are stabilized by Leu-110, whereas the hydrophobic core is destabilized in the SCR by Ala residues at three consecutive d positions. Our hypothesis is that the stabilization of the individual α-helices provides an optimum stability and allows functionally beneficial dynamic motion between the α-helices that is critical for the transmission of stabilizing information along the coiled-coil from the SCR. We prepared three recombinant (rat) Tm(1-131) proteins, including the wild type sequence, a destabilizing mutation L110A, and a stabilizing mutation A109L. These proteins were evaluated by circular dichroism (CD) and differential scanning calorimetry. The single mutation L110A destabilizes the entire Tm(1-131) molecule, showing that the effect of this mutation is transmitted 165 Å along the coiled-coil in the N-terminal direction. The single mutation A109L prevents the SCR from transmitting stabilizing information and separates the coiled-coil into two domains, one that is ∼9 °C more stable than wild type and one that is ∼16 °C less stable. We know of no other example of the substitution of a stabilizing Leu residue in a coiled-coil hydrophobic core position d that causes this dramatic effect. We demonstrate the importance of the SCR in controlling and transmitting the stability signal along this rodlike molecule.
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Affiliation(s)
- J Paul Kirwan
- From the Program in Structural Biology and Biophysics, Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Denver, Aurora, Colorado 80045
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Introducing a special edition of the Journal of Muscle Research and Cell Motility on tropomyosin: form and function. J Muscle Res Cell Motil 2013; 34:151-3. [PMID: 24101402 DOI: 10.1007/s10974-013-9361-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 09/19/2013] [Indexed: 10/26/2022]
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Stafford WF, Lee E, Graceffa P. Equilibrium self-association of tropomyosin. FEBS Lett 2012; 586:3840-2. [PMID: 23022558 DOI: 10.1016/j.febslet.2012.08.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 08/27/2012] [Accepted: 08/28/2012] [Indexed: 01/14/2023]
Abstract
It has recently been reported that tropomyosin exists exclusively as a dimer in physiological salt conditions. It is shown in the present work using analytical ultracentrifugation that, on the contrary, tropomyosin is in equilibrium between monomer, dimer and tetramer with a weak tendency to dimerize and tetramerize. Such a finding has consequences for the assembly of the tropomyosin-actin complex.
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Affiliation(s)
- Walter F Stafford
- Boston Biomedical Research Institute, Watertown, MA 02472, United States
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30
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Kalyva A, Schmidtmann A, Geeves MA. In vitro formation and characterization of the skeletal muscle α·β tropomyosin heterodimers. Biochemistry 2012; 51:6388-99. [PMID: 22812662 PMCID: PMC3535570 DOI: 10.1021/bi300340r] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Tropomyosin (Tm) is a dimer made of two alpha helical chains associated into a parallel coiled-coil. In mammalian skeletal and cardiac muscle, the Tm is expressed from two separate genes to give the α- and β-Tm isoforms. These associate in vivo to form homo- (α(2)) and heterodimers (α·β) with little β(2) normally observed. The proportion of α(2) vs α·β varies across species and across muscle types from almost 100% α(2)- to 50% α·β-Tm. The ratio can also vary during development and in disease. The functional significance of the presence of these two isoforms has not been defined because it is difficult to isolate or purify the α·β dimer for functional studies. Here we report an effective method for purifying bacterially expressed Tm as α·β dimers using a cleavable N-terminal tag on one of the two chains. The same method can be used to isolate Tm dimers in which one chain carries a mutation. We go on to show that the α·β dimers differ in key properties (actin affinity, thermal stability) from either the α(2)- or β(2)-Tm. However, the ability to regulate myosin binding when combined with cardiac troponin appears unaffected.
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31
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Koubassova NA, Tsaturyan AK. Molecular mechanism of actin-myosin motor in muscle. BIOCHEMISTRY (MOSCOW) 2012; 76:1484-506. [PMID: 22339600 DOI: 10.1134/s0006297911130086] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The interaction of actin and myosin powers striated and smooth muscles and some other types of cell motility. Due to its highly ordered structure, skeletal muscle is a very convenient object for studying the general mechanism of the actin-myosin molecular motor. The history of investigation of the actin-myosin motor is briefly described. Modern concepts and data obtained with different techniques including protein crystallography, electron microscopy, biochemistry, and protein engineering are reviewed. Particular attention is given to X-ray diffraction studies of intact muscles and single muscle fibers with permeabilized membrane as they give insight into structural changes that underlie force generation and work production by the motor. Time-resolved low-angle X-ray diffraction on contracting muscle fibers using modern synchrotron radiation sources is used to follow movement of myosin heads with unique time and spatial resolution under near physiological conditions.
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Affiliation(s)
- N A Koubassova
- Institute of Mechanics, Lomonosov Moscow State University, Moscow, Russia.
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32
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Nevzorov IA, Levitsky DI. Tropomyosin: double helix from the protein world. BIOCHEMISTRY (MOSCOW) 2012; 76:1507-27. [PMID: 22339601 DOI: 10.1134/s0006297911130098] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This review concerns the structure and functions of tropomyosin (TM), an actin-binding protein that plays a key role in the regulation of muscle contraction. The TM molecule is a dimer of α-helices, which form a coiled-coil. Recent views on the TM structure are analyzed, and special attention is concentrated on those structural traits of the TM molecule that distinguish it from the other coiled-coil proteins. Modern data are presented on TM functional properties, such as its interaction with actin and ability to move on the surface of actin filaments, which underlies the regulation of the actin-myosin interaction upon contraction of skeletal and cardiac muscles. Also, part of the review is devoted to analysis of the effects of mutations in TM genes associated with muscle diseases (myopathies) on the structure and functions of TM.
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Affiliation(s)
- I A Nevzorov
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, Russia.
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33
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Choi C, Kim D, Kim S, Jeong S, Song E, Helfman DM. From skeletal muscle to cancer: insights learned elucidating the function of tropomyosin. J Struct Biol 2011; 177:63-9. [PMID: 22119848 DOI: 10.1016/j.jsb.2011.11.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 11/08/2011] [Accepted: 11/09/2011] [Indexed: 12/17/2022]
Abstract
The tropomyosins (Tms) are a family of actin filament binding proteins that possess a simple dimeric α-helical coiled-coil structure along their entire length. Our knowledge of Tm structure and function has greatly expanded since they were first discovered in skeletal muscle almost 65 years ago. In multicellular organisms they exhibit extensive cell type specific isoform diversity. In this essay we discuss the genetic mechanisms by which this diversity is generated and its significance to actin-based cellular functions.
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Affiliation(s)
- Cheolwon Choi
- Department of Biological Sciences, Korean Advanced Institute of Science and Technology, Daejeon, Republic of Korea
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34
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Lees JG, Bach CTT, O'Neill GM. Interior decoration: tropomyosin in actin dynamics and cell migration. Cell Adh Migr 2011; 5:181-6. [PMID: 21173575 DOI: 10.4161/cam.5.2.14438] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Cell migration and invasion requires the precise temporal and spatial orchestration of a variety of biological processes. Filaments of polymerized actin are critical players in these diverse processes, including the regulation of cell anchorage points (both cell-cell and cell-extracellular matrix), the uptake and delivery of molecules via endocytic pathways and the generation of force for both membrane protrusion and retraction. How the actin filaments are specialized for each of these discrete functions is yet to be comprehensively elucidated. The cytoskeletal tropomyosins are a family of actin associating proteins that form head-to-tail polymers which lay in the major groove of polymerized actin filaments. In the present review we summarize the emerging isoform-specific functions of tropomyosins in cell migration and invasion and discuss their potential roles in the specialization of actin filaments for the diverse cellular processes that together regulate cell migration and invasion.
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Affiliation(s)
- Justin G Lees
- Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
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35
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Lassing I, Hillberg L, Höglund AS, Karlsson R, Schutt C, Lindberg U. Tropomyosin is a tetramer under physiological salt conditions. Cytoskeleton (Hoboken) 2010; 67:599-607. [PMID: 20658558 DOI: 10.1002/cm.20470] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tropomyosin (TM) is a coiled-coil dimer of alpha-helical peptides, which self associates in a head- to-tail fashion along actin polymers, conferring stability to the microfilaments and serving a regulatory function in acto-myosin driven force generation. While the major amount of TM is associated with filaments also in non-muscle cells, it was recently reported that there are isoform-specific pools of TM multimers (not associated with F-actin), which appear to be utilized during actin polymerization and reformed during depolymerization. To determine the size of these multimers, skeletal muscle TM was studied under different salt conditions using gel-filtration and sucrose gradient sedimentation, and compared with purified non-muscle TM 1 and 5, as well as with TM present in non-muscle cell extracts and skeletal muscle TM added to such extracts. Under physiological salt conditions TM appears as a single homogenous peak with the Stokes radius 8.2 nm and the molecular weight (mw) 130,000. The corresponding values for TM 5 are 7.7 nm and 104,000, respectively. This equals four peptides, implying that native TM is a tetramer in physiological salt. It is therefore concluded that the TM multimers are tetramers.
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Affiliation(s)
- Ingrid Lassing
- Department of Cell Biology, The Wenner-Gren Institute, Stockholm University, Sweden.
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36
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Ohshiro K, Obinata T, Dennisson JG, Ogasawara M, Sato N. Troponin in both Smooth and Striated Muscles of Ascidian Ciona intestinalis Functions as a Ca2+-Dependent Accelerator of Actin−Myosin Interaction. Biochemistry 2010; 49:9563-71. [DOI: 10.1021/bi101295m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Katsushi Ohshiro
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Takashi Obinata
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
- Department of Health and Nutrition, Teikyo-Heisei University, Higashi Ikebukuro 2-51-4, Toshima-ku, Tokyo 170-8445, Japan
| | - Jeanette G. Dennisson
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Michio Ogasawara
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Naruki Sato
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
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37
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Schaub MC, Perry SV, Hartshorne DJ. The effect of tropomyosin on the adenosine triphosphatase activity of desensitized actomyosin. Biochem J 2010; 105:1235-43. [PMID: 16742551 PMCID: PMC1198446 DOI: 10.1042/bj1051235] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
1. Tropomyosin preparations of the Bailey type, and those prepared in the presence of dithiothreitol to prevent oxidation of protein thiol groups, inhibit the Ca(2+)-activated adenosine triphosphatase (ATPase) of desensitized actomyosin by up to 60%. 2. The inhibitory activity of myofibrillar extracts and tropomyosin survives various agents known to denature proteins but to the action of which tropomyosin is unusually stable, namely heating at 100 degrees and mild tryptic digestion. It is destroyed by prolonged treatment with trypsin. 3. The ethylenedioxybis-(ethyleneamino)tetra-acetic acid (EGTA)-sensitizing factor present in extracts of natural actomyosin and myofibrils could be selectively destroyed, leaving unchanged the inhibitory effect on the Ca(2+)-activated ATPase. There was no correlation between the EGTA-sensitizing and the Ca(2+)-activated inhibitory activities of tropomyosin prepared under different conditions. 4. Optimum inhibition was achieved when tropomyosin and the myosin of desensitized actomyosin were present in approximately equimolar proportions. Tropomyosin had no effect on the Ca(2+)-activated ATPase of myosin measured under similar conditions. 5. Evidence is presented showing that the tropomyosin binds to desensitized actomyosin under the conditions in which the ATPase is inhibited.
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Affiliation(s)
- M C Schaub
- Department of Biochemistry, University of Birmingham
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38
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Dennisson JG, Tando Y, Sato N, Ogasawara M, Kubokawa K, Obinata T. Functional Characteristics of Amphioxus Troponin in Regulation of Muscle Contraction. Zoolog Sci 2010; 27:461-9. [DOI: 10.2108/zsj.27.461] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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39
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Wang CLA, Coluccio LM. New insights into the regulation of the actin cytoskeleton by tropomyosin. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 281:91-128. [PMID: 20460184 DOI: 10.1016/s1937-6448(10)81003-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The actin cytoskeleton is regulated by a variety of actin-binding proteins including those constituting the tropomyosin family. Tropomyosins are coiled-coil dimers that bind along the length of actin filaments. In muscles, tropomyosin regulates the interaction of actin-containing thin filaments with myosin-containing thick filaments to allow contraction. In nonmuscle cells where multiple tropomyosin isoforms are expressed, tropomyosins participate in a number of cellular events involving the cytoskeleton. This chapter reviews the current state of the literature regarding tropomyosin structure and function and discusses the evidence that tropomyosins play a role in regulating actin assembly.
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40
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The Shape and Flexibility of Tropomyosin Coiled Coils: Implications for Actin Filament Assembly and Regulation. J Mol Biol 2010; 395:327-39. [DOI: 10.1016/j.jmb.2009.10.060] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 10/19/2009] [Accepted: 10/27/2009] [Indexed: 12/18/2022]
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41
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ENGSTROM A. Submicroscopic Structure of Striated Muscle. Scandinavian Journal of Clinical and Laboratory Investigation 2009; 2:252-6. [PMID: 14787354 DOI: 10.3109/00365515009049879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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42
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Gunning P. Introduction and historical perspective. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 644:1-5. [PMID: 19209809 DOI: 10.1007/978-0-387-85766-4_1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Tropomyosin is a coiled coil dimer which forms a polymer along the major groove of the majority of actin filaments. It is therefore one of the two primary components of the actin filament. Our understanding of the biological function of tropomyosin has been driven almost entirely by its role in striated muscle. This reflects both its original discovery as part of the thin filament in skeletal muscle and its pivotal role in regulating muscle contraction. In contrast, its role in the function of the cytoskeleton of all cells has been poorly understood due, at least in part, to the technical challenge of deciphering the function of a large number of isoforms. This book has brought together many of the leading researchers who have defined the function of tropomyosin in both normal and pathological conditions. Each author brings their own perspective in a series of stand alone reviews of the areas of tropomyosin research they have played a major role in defining.
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Affiliation(s)
- Peter Gunning
- Oncology Research Unit, Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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43
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Pont MJ, Woods EF. Denaturation of tropomyosin by guanidine hydrochloride. INTERNATIONAL JOURNAL OF PROTEIN RESEARCH 2009; 3:177-83. [PMID: 5126610 DOI: 10.1111/j.1399-3011.1971.tb01710.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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44
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Woods EF. Studies on the denaturation of tropomyosin and light meromyosin. INTERNATIONAL JOURNAL OF PROTEIN RESEARCH 2009; 1:29-43. [PMID: 4953053 DOI: 10.1111/j.1399-3011.1969.tb01624.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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45
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Jarosch R. Large-scale models reveal the two-component mechanics of striated muscle. Int J Mol Sci 2008; 9:2658-2723. [PMID: 19330099 PMCID: PMC2635638 DOI: 10.3390/ijms9122658] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Revised: 12/11/2008] [Accepted: 12/15/2008] [Indexed: 11/30/2022] Open
Abstract
This paper provides a comprehensive explanation of striated muscle mechanics and contraction on the basis of filament rotations. Helical proteins, particularly the coiled-coils of tropomyosin, myosin and alpha-actinin, shorten their H-bonds cooperatively and produce torque and filament rotations when the Coulombic net-charge repulsion of their highly charged side-chains is diminished by interaction with ions. The classical "two-component model" of active muscle differentiated a "contractile component" which stretches the "series elastic component" during force production. The contractile components are the helically shaped thin filaments of muscle that shorten the sarcomeres by clockwise drilling into the myosin cross-bridges with torque decrease (= force-deficit). Muscle stretch means drawing out the thin filament helices off the cross-bridges under passive counterclockwise rotation with torque increase (= stretch activation). Since each thin filament is anchored by four elastic alpha-actinin Z-filaments (provided with force-regulating sites for Ca(2+) binding), the thin filament rotations change the torsional twist of the four Z-filaments as the "series elastic components". Large scale models simulate the changes of structure and force in the Z-band by the different Z-filament twisting stages A, B, C, D, E, F and G. Stage D corresponds to the isometric state. The basic phenomena of muscle physiology, i. e. latency relaxation, Fenn-effect, the force-velocity relation, the length-tension relation, unexplained energy, shortening heat, the Huxley-Simmons phases, etc. are explained and interpreted with the help of the model experiments.
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Affiliation(s)
- Robert Jarosch
- Formerly Institute of Plant Physiology, University of Salzburg, Hellbrunnerstrasse 34, A-5020 Salzburg, Austria. E-Mail:
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46
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Hamoir G. Contribution A L'étude Des Protéines Musculaires de Poisson. Regherghes sur le Muscle Strié de la Carpe. ACTA ACUST UNITED AC 2008. [DOI: 10.3109/13813455509146562] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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47
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Shark skeletal muscle tropomyosin is a phosphoprotein. J Muscle Res Cell Motil 2008; 29:101-7. [DOI: 10.1007/s10974-008-9143-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Accepted: 08/05/2008] [Indexed: 11/26/2022]
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48
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Abstract
The actin-binding proteins, nebulette, and nebulin, are comprised of a four-domain layout containing an acidic N-terminal region, a repeat domain, a serine-rich-linker region, and a Src homology-3 domain. Both proteins contain homologous N-terminal regions that are predicted to be in different environments within the sarcomere. The nebulin acidic N-terminal region is found at the distal ends of the thin filaments. Nebulette, however, is predicted to extend 150 nm from the center of the Z-line. To dissect out the functions of the N-terminal domain of nebulette, we have performed a yeast two-hybrid screen using nebulette residues 1-86 as bait. We have identified filamin-C, ZASP-1, and tropomyosin-1 as binding partners. Characterization of the nebulette-filamin interaction indicates that filamin-C predominantly interacts with the modules. These data suggest that filamin-C, a known component of striated muscle Z-lines, interacts with nebulette modules.
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Affiliation(s)
- William B Holmes
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536, USA
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49
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Ohtsuki I, Morimoto S. Troponin: Regulatory function and disorders. Biochem Biophys Res Commun 2008; 369:62-73. [DOI: 10.1016/j.bbrc.2007.11.187] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2007] [Accepted: 11/22/2007] [Indexed: 11/29/2022]
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50
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Gunning P, O'Neill G, Hardeman E. Tropomyosin-based regulation of the actin cytoskeleton in time and space. Physiol Rev 2008; 88:1-35. [PMID: 18195081 DOI: 10.1152/physrev.00001.2007] [Citation(s) in RCA: 352] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Tropomyosins are rodlike coiled coil dimers that form continuous polymers along the major groove of most actin filaments. In striated muscle, tropomyosin regulates the actin-myosin interaction and, hence, contraction of muscle. Tropomyosin also contributes to most, if not all, functions of the actin cytoskeleton, and its role is essential for the viability of a wide range of organisms. The ability of tropomyosin to contribute to the many functions of the actin cytoskeleton is related to the temporal and spatial regulation of expression of tropomyosin isoforms. Qualitative and quantitative changes in tropomyosin isoform expression accompany morphogenesis in a range of cell types. The isoforms are segregated to different intracellular pools of actin filaments and confer different properties to these filaments. Mutations in tropomyosins are directly involved in cardiac and skeletal muscle diseases. Alterations in tropomyosin expression directly contribute to the growth and spread of cancer. The functional specificity of tropomyosins is related to the collaborative interactions of the isoforms with different actin binding proteins such as cofilin, gelsolin, Arp 2/3, myosin, caldesmon, and tropomodulin. It is proposed that local changes in signaling activity may be sufficient to drive the assembly of isoform-specific complexes at different intracellular sites.
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Affiliation(s)
- Peter Gunning
- Oncology Research Unit, The Children's Hospital at Westmead, and Muscle Development Unit, Children's Medical Research Institute, Westmead; New South Wales, Australia.
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