Implications of Tropomyosin Phosphorylation in Normal and Cardiomyopathic Hearts

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David F Wieczorek

Abstract

Numerous molecular and biochemical processes regulate protein production in the cell. One of these processes, phosphorylation, allows the cell to rapidly adapt to changing physiological situations. In terminally differentiated cells, such as cardiomyocytes, phosphorylation of sarcomeric proteins controls contraction and relaxation under both normal and stressful conditions. The focus of this review is how phosphorylation of sarcomeric proteins alters physiological performance in cardiac muscle with a particular emphasis on the thin filament protein tropomyosin. This topic is addressed by the examination of tropomyosin isoform expression and its phosphorylation state from embryonic to adult murine development. Next, studies are examined which utilize in vivo model systems to express phosphorylation mimetics and de-phosphorylation genetically-altered tropomyosin transgene constructs. Results show that tropomyosin isoform expression is highly regulated, along with its phosphorylation state. Transgenic mouse hearts which express high levels of a constitutively phosphorylated tropomyosin develop a severe dilated cardiomyopathy and die within a month. A more moderate expression of this phosphorylation mimetic leads to normal systolic performance, but impaired diastolic function. When tropomyosin is dephosphorylated, the transgenic mice develop a compensated cardiac hypertrophy without systolic or diastolic alterations. Interestingly, when dephosphorylated tropomyosin is co-expressed with a hypertrophic cardiomyopathy tropomyosin mutation, the pathological phenotype is rescued with improved cardiac function and no indices of systolic or diastolic dysfunction. These studies demonstrate the functional significance of tropomyosin phosphorylation in determining cardiac performance during both normal and pathological conditions.

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How to Cite
WIECZOREK, David F. Implications of Tropomyosin Phosphorylation in Normal and Cardiomyopathic Hearts. Medical Research Archives, [S.l.], v. 10, n. 8, sep. 2022. ISSN 2375-1924. Available at: <https://esmed.org/MRA/mra/article/view/3103>. Date accessed: 07 oct. 2022. doi: https://doi.org/10.18103/mra.v10i8.3103.
Section
Research Articles

References

1. Muthuchamy M, Pajak L, Howles P, Doetschman T, Wieczorek DF. Developmental analysis of tropomyosin gene expression in embryonic stem cells and mouse embryos. Mol Cell Biol. 1993; 13:3311-3323.
2. Cummins P, Perry SV. Chemical and immunochemical characteristics of tropomyosins from striated and smooth muscle. Biochem J 1974;141:43-49.
3. Vandekerckhove J, Bugaisk G, Buckingham M. Simultaneous expression of skeletal muscle and heart actin proteins in various striated muscle tissues and cells. A quantitative determination of the two actin isoforms. J Biol Chem 1986;261:1838-1843.
4. Lin YH, Warren CM, Li J, McKinsey TA, Russell B. Myofibril growth during cardiac hypertrophy is regulated through dual phosphorylation and acetylation of the actin capping protein CapZ. Cell Signal 2016;28:1015-1024.
5. Scruggs SB, Wang D, Ping P. PRKCE gene encoding protein kinase C-epsilon – Dual roles at sarcomeres and mitochondria in cardiomyocytes. Gene 2016;590:90-96.
6. Russell B, Solis C. Mechanosignaling pathways alter muscle structure and function by post-translational modification of existing sarcomeric proteins to optimize energy usage. J Mus Res Cell Motil 2021;42:367-380.
7. Hildago C, Granzier H. Tuning the molecular giant titin through phosphorylation: role in health and disease. Trends Cardiovasc Med 2013;23:165-171.
8. van der Velden J, Stienen G. Cardiac disorders and pathophysiology of sarcomeric proteins. Physiol Rev 2019;99:381-426.
9. Noland TA Jr, Kuo JF. Phosphorylation of cardiac myosin light chain 2 by protein kinase C and myosin light chain kinases increases Ca2+-stimulated actomyosin MgATPase activity. Biochem Bioiphys Res Commun 1993;193:254-260.
10. Colson BA, Locher MR, Bekyarova T, et al. Differential roles of regulatory light chain and myosin binding protein-C phosphorylations in the modulation of cardiac force development. J Physiol 2010;588:981-993.
11. Moss RL, Fitzsimons DP, Ralphe JC. Cardiac MyBP-C regulates the rate and force of contraction in mammalian myocardium. Circ Res 2015;116:183-192.
12. Saber W, Begin KJ, Warshaw DM, VanBuren P. Cardiac myosin binding protein-C modulates actomyosin binding and kinetics in the in vitro motility assay. J Mol Cell Cardiol 2008;44:1053-1061.
13. Shaffer JF, Kensler RW, Harris SP. The myosin-binding protein C motif binds to F-actin in a phosphorylation-sensitive manner. J Biol Chem 2009;284:12318-12327.
14. Weisberg A, Winegrad S. Alteration of myosin cross bridges by phosphorylation of myosin-binding protein C in cardiac muscle. Proc Natl Acad Sci USA 1996;93:8999-9003.
15. Wang L, Ji X, Barefield D, Sadayappan S, Kawai M. Phosphorylation of cMyBP-C affects contractile mechanisms in a site-specific manner. Biophys J 2014;106:1112-1122.
16. Sumandea M, Pyle WG, Kobayashi T, de Tombe PP, Solaro RJ. Identification of a functionally critical protein kinase C phosphorylation residue of cardiac troponin T. J Biol Chem 2003;278:35135-35144.
17. Kentish JC, McKloskey DF, Layland J. et al. Phosphorylation of troponin I by protein kinase A accelerates relaxation and cross-bridge cycle kinetics in mouse ventricular muscle. Circ Res 2001;88:1059-1065.
18. Solaro RJ, Kobayashi T. Protein phosphorylation and signal transduction in cardiac thin filaments. J Biol Chem 2011;286:9935-9940.
19. Rajan S, Jagatheesan G, Karam CN, et al. Molecular and functional characterization of a novel cardiac-specific human tropomyosin isoform. Circ 2010;121:410-418.
20. Muthuchamy M, Grupp IL, Grupp G., et al. Molecular and physiological effects of overexpressing striated muscle β-tropomyosin in the adult murine heart. J Biol Chem 1995;270:30593-30603.
21. Palmiter KA, Kitada Y, Muthuchamy M, Wieczorek DF, Solaro RJ. Exchange of β- for α-tropomyosin in hearts of transgenic mice induces changes in thin filament response to Ca2+, strong cross-bridge binding, and protein phosphorylation. J Biol Chem 1996:271:11611-11614.
22. Wolska BM, Keller RS, Evans CC, et al. Correlation between myofilament response to Ca2+ and altered dynamics of contraction and relaxation in transgenic cardiac cells that express betα-tropomyosin. Circ Res 1999;84:745-751.
23. Muthuchamy M, Boivin GP, Grupp IL, Wieczorek DF. β-tropomyosin overexpression induces severe cardiac abnormalities. J Mol Cell Cardiol 1998;30:1545-1557.
24. Butters C, Willadsen K, Tobacman L. Cooperative interactions between adjacent troponin-tropomyosin complexes may be transmitted through the actin filament. J Biol Chem 1993;268:15565-15570.
25. Walsh T, Trueblood C, Evans R, Weber A. Removal of tropomyosin overlap and the co-operative response to increasing calcium concentrations of the acto-subfragment-1 ATPase. J Mol Biol 1984;182:265-269.
26. Ribulow H, Barany M. Phosphorylation of tropomyosin in live frog muscle. Arch Biochem Biophys 1977;179:718-720.
27. Heeley DH, Moir AJ, Perry SV. Phosphorylation of tropomyosin during development in mammalian striated muscle. FEBS Lett 1982;146:115-118.
28. Schulz EM, Wieczorek DF. Tropomyosin de-phosphorylation in the heart: what are the consequences? J Muscle Res Cell Motil 2013;239-246.
29. Heeley DH. Phosphorylation of tropomyosin in striated muscle. J Muscle Res Cell Motil 2013:34:233-237.
30. Nixon B, Liu B, Scellini B., et al. Tropomyosin Ser-283 pseudo-phosphorylation slows myofibril relaxation. Arch Biochem Biophys. 2013;535:30-38.
31. Lehman W, Medlock G, Li X, et al. Phosphorylation of Ser283 enhances the stiffness of the tropomyosin head-to-tail overlap domain. Arch Biochem Biophys. 2015;571:10-15.
32. Madhushika A, Silva M, Goonasekara CL, Hayley M, Heeley DH. Further investigation into the biochemical effects of phosphorylation of tropomyosin Tpm1.1(a). Serine-283 is in communication with the midregion. Biochem 2020;59:4725-4734.
33. Rajan S, Jagatheesan G, Petrashevskaya N., et al. Tropomyosin pseudo-phosphorylation results in dilated cardiomyopathy. J Biol Chem 2019;294:2913-2923.
34. Schulz EM, Correll RN, Sheikh HN, et al. Tropomyosin dephosphorylation results in compensated cardiac hypertrophy. J Biol Chem 2012;287:44478-44489.
35. Muthuchamy M, Pieples K, Rethinasamy P. et al. Mouse model of a familial hypertrophic cardiomyopathy mutation in alphα-tropomyosin manifests cardiac dysfunction. Circ Res 1999;85:47-56.
36. Prabhakar R, Boivin GP, Grupp IL., et al. A familial hypertrophic cardiomyopathy alphα-tropomyosin mutation causes severe cardiac hypertrophy and death in mice. J Mol Cell Cardiol 2001; 33:1815-1828.
37. Prabhakar R, Petrashevskaya N, Schwartz A. et al. A mouse model of familial hypertrophic cardiomyopathy caused by a alphα-tropomyosin mutation. Mol Cell Biochem 2003;251:33-42.
38. Wieczorek DF, Jagatheesan G, Rajan S. The role of tropomyosin in heart disease. Adv Exp Med Biol 2008;644:132-142.
39. Schulz EM, Wilder T, Chowdhury S, et al. Decreasing tropomyosin phosphorylation rescues tropomyosin-induced familial hypertrophic cardiomyopathy. J Biol Chem 2013;288:28925-28935.
40. Loong CK, Zhou HX, Chase PB. Persistence length of human cardiac α-tropomyosin measured by single molecule direct probe microscopy. PLoS One 2012;7:e39676.
41. Ly S, Lehrer SS. Long-range effects of familial hypertrophic cardiomyopathy mutations E180G and D175N on the properties of tropomyosin. Biochemistry 2012;51:6413-6420.
42. Nefedova VV, Koubassova N, Borzova V., et al. Tropomyosin pseudo-phosphorylation can rescue the effects of cardiomyopathy-associated mutations. International J Biological Macromolecules 2021:166:424-434.