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Gonchar AD, Kopylova GV, Kochurova AM, Berg VY, Shchepkin DV, Koubasova NA, Tsaturyan AK, Kleymenov SY, Matyushenko AM, Levitsky DI. Effects of myopathy-causing mutations R91P and R245G in the TPM3 gene on structural and functional properties of slow skeletal muscle tropomyosin. Biochem Biophys Res Commun 2020; 534:8-13. [PMID: 33307294 DOI: 10.1016/j.bbrc.2020.11.103] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 11/26/2020] [Indexed: 12/16/2022]
Abstract
Tropomyosin (Tpm) is an actin-binding protein that plays a crucial role in the regulation of muscle contraction. Numerous point mutations in the TPM3 gene encoding Tpm of slow skeletal muscles (Tpm 3.12 or γ-Tpm) are associated with the genesis of various congenital myopathies. Two of these mutations, R91P and R245G, are associated with congenital fiber-type disproportion (CFTD) characterized by hypotonia and generalized muscle weakness. We applied various methods to investigate how these mutations affect the structural and functional properties of γγ-Tpm homodimers. The results show that both these mutations lead to strong structural changes in the γγ-Tpm molecule and significantly impaired its functional properties. These changes in the Tpm properties caused by R91P and R245G mutations give insight into the molecular mechanism of the CFTD development and the weakness of slow skeletal muscles observed in this inherited disease.
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Affiliation(s)
- Anastasiia D Gonchar
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia; Department of Biochemistry, School of Biology, Moscow State University, Moscow, 119234, Russia
| | - Galina V Kopylova
- Institute of Immunology and Physiology, The Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Anastasia M Kochurova
- Institute of Immunology and Physiology, The Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Valentina Y Berg
- Institute of Immunology and Physiology, The Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Daniil V Shchepkin
- Institute of Immunology and Physiology, The Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | | | | | - Sergey Y Kleymenov
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia; Koltzov Institute of Developmental Biology of the Russian Academy of Sciences, 119334, Moscow, Russia
| | - Alexander M Matyushenko
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
| | - Dmitrii I Levitsky
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia.
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Matyushenko AM, Shchepkin DV, Kopylova GV, Bershitsky SY, Levitsky DI. Unique functional properties of slow skeletal muscle tropomyosin. Biochimie 2020; 174:1-8. [PMID: 32224097 DOI: 10.1016/j.biochi.2020.03.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/19/2020] [Accepted: 03/19/2020] [Indexed: 12/20/2022]
Abstract
Tropomyosin (Tpm) is an α-helical coiled-coil actin-binding protein playing an essential role in the regulation of muscle contraction. The α- (Tpm 1.1) and γ- (Tpm 3.12) Tpm isoforms are expressed in fast and slow human skeletal muscles, respectively, while β-Tpm (Tpm 2.2) is expressed in both muscle types. This results in the formation of Tpm αα- and γγ-homodimers as well as αβ- and γβ-heterodimers. The properties of αα-homodimer are well studied, whereas very little is known about the functional properties of γγ-homodimer and γβ-heterodimer. We investigated interaction characteristics of Tpm γγ-homodimer and γβ-heterodimer with actin filaments and Ca2+-regulation of actin-myosin interaction on myosin from fast and slow skeletal muscles. The results showed that complexes formed by γγ-Tpm and γβ-Tpm with F-actin are more stable than those with αα-Tpm and αβ-Tpm. The maximum sliding speed of regulated thin filaments with either γγ-Tpm or γβ-Tpm moving over skeletal myosin was significantly less than that of the filaments with αα-Tpm or αβ-Tpm. The results indicate that isoforms of Tpm along with isoforms of myosin determine of functional properties of skeletal muscles and support an idea on the combined expression of myosin and Tpm isoforms.
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Affiliation(s)
- Alexander M Matyushenko
- A. N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
| | - Daniil V Shchepkin
- Institute of Immunology and Physiology of the Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Galina V Kopylova
- Institute of Immunology and Physiology of the Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Sergey Y Bershitsky
- Institute of Immunology and Physiology of the Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Dmitrii I Levitsky
- A. N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia; A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119234, Russia.
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