| Structural highlights
Disease
[TNNC1_HUMAN] Defects in TNNC1 are the cause of cardiomyopathy dilated type 1Z (CMD1Z) [MIM:611879]. Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death.[1] Defects in TNNC1 are the cause of familial hypertrophic cardiomyopathy type 13 (CMH13) [MIM:613243]. A hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum. The symptoms include dyspnea, syncope, collapse, palpitations, and chest pain. They can be readily provoked by exercise. The disorder has inter- and intrafamilial variability ranging from benign to malignant forms with high risk of cardiac failure and sudden cardiac death.[2] [3] [4] [5] [TNNI3_HUMAN] Defects in TNNI3 are the cause of familial hypertrophic cardiomyopathy type 7 (CMH7) [MIM:613690]. Familial hypertrophic cardiomyopathy is a hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum. The symptoms include dyspnea, syncope, collapse, palpitations, and chest pain. They can be readily provoked by exercise. The disorder has inter- and intrafamilial variability ranging from benign to malignant forms with high risk of cardiac failure and sudden cardiac death.[6] [7] [8] [9] [10] Defects in TNNI3 are the cause of familial restrictive cardiomyopathy type 1 (RCM1) [MIM:115210]. RCM1 is a heart muscle disorder characterized by impaired filling of the ventricles with reduced diastolic volume, in the presence of normal or near normal wall thickness and systolic function.[11] Defects in TNNI3 are the cause of cardiomyopathy dilated type 2A (CMD2A) [MIM:611880]. Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death.[12] Defects in TNNI3 are the cause of cardiomyopathy dilated type 1FF (CMD1FF) [MIM:613286]. Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death.
Function
[TNNC1_HUMAN] Troponin is the central regulatory protein of striated muscle contraction. Tn consists of three components: Tn-I which is the inhibitor of actomyosin ATPase, Tn-T which contains the binding site for tropomyosin and Tn-C. The binding of calcium to Tn-C abolishes the inhibitory action of Tn on actin filaments. [TNNI3_HUMAN] Troponin I is the inhibitory subunit of troponin, the thin filament regulatory complex which confers calcium-sensitivity to striated muscle actomyosin ATPase activity.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Cardiac troponin C is the Ca2+-dependent switch for heart muscle contraction. Troponin C is associated with various other proteins including troponin I and troponin T. The interaction between the subunits within the troponin complex is of critical importance in understanding contractility. Following a Ca2+ signal to begin contraction, the inhibitory region of troponin I comprising residues Thr128-Arg147 relocates from its binding surface on actin to troponin C, triggering movement of troponin-tropomyosin within the thin filament and thereby freeing actin-binding site(s) for interactions with the myosin ATPase of the thick filament to generate the power stroke. The structure of calcium-saturated cardiac troponin C (C-domain) in complex with the inhibitory region of troponin I was determined using multinuclear and multidimensional nuclear magnetic resonance spectroscopy. The structure of this complex reveals that the inhibitory region adopts a helical conformation spanning residues Leu134-Lys139, with a novel orientation between the E- and H-helices of troponin C, which is largely stabilized by electrostatic interactions. By using isotope labeling, we have studied the dynamics of the protein and peptide in the binary complex. The structure of this inhibited complex provides a framework for understanding into interactions within the troponin complex upon heart contraction.
Structure and dynamics of the C-domain of human cardiac troponin C in complex with the inhibitory region of human cardiac troponin I.,Lindhout DA, Sykes BD J Biol Chem. 2003 Jul 18;278(29):27024-34. Epub 2003 May 5. PMID:12732641[13]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Mogensen J, Murphy RT, Shaw T, Bahl A, Redwood C, Watkins H, Burke M, Elliott PM, McKenna WJ. Severe disease expression of cardiac troponin C and T mutations in patients with idiopathic dilated cardiomyopathy. J Am Coll Cardiol. 2004 Nov 16;44(10):2033-40. PMID:15542288 doi:S0735-1097(04)01700-0
- ↑ Hoffmann B, Schmidt-Traub H, Perrot A, Osterziel KJ, Gessner R. First mutation in cardiac troponin C, L29Q, in a patient with hypertrophic cardiomyopathy. Hum Mutat. 2001 Jun;17(6):524. PMID:11385718 doi:10.1002/humu.1143
- ↑ Schmidtmann A, Lindow C, Villard S, Heuser A, Mugge A, Gessner R, Granier C, Jaquet K. Cardiac troponin C-L29Q, related to hypertrophic cardiomyopathy, hinders the transduction of the protein kinase A dependent phosphorylation signal from cardiac troponin I to C. FEBS J. 2005 Dec;272(23):6087-97. PMID:16302972 doi:10.1111/j.1742-4658.2005.05001.x
- ↑ Landstrom AP, Parvatiyar MS, Pinto JR, Marquardt ML, Bos JM, Tester DJ, Ommen SR, Potter JD, Ackerman MJ. Molecular and functional characterization of novel hypertrophic cardiomyopathy susceptibility mutations in TNNC1-encoded troponin C. J Mol Cell Cardiol. 2008 Aug;45(2):281-8. doi: 10.1016/j.yjmcc.2008.05.003. Epub , 2008 May 11. PMID:18572189 doi:10.1016/j.yjmcc.2008.05.003
- ↑ Pinto JR, Parvatiyar MS, Jones MA, Liang J, Ackerman MJ, Potter JD. A functional and structural study of troponin C mutations related to hypertrophic cardiomyopathy. J Biol Chem. 2009 Jul 10;284(28):19090-100. doi: 10.1074/jbc.M109.007021. Epub, 2009 May 12. PMID:19439414 doi:10.1074/jbc.M109.007021
- ↑ Kimura A, Harada H, Park JE, Nishi H, Satoh M, Takahashi M, Hiroi S, Sasaoka T, Ohbuchi N, Nakamura T, Koyanagi T, Hwang TH, Choo JA, Chung KS, Hasegawa A, Nagai R, Okazaki O, Nakamura H, Matsuzaki M, Sakamoto T, Toshima H, Koga Y, Imaizumi T, Sasazuki T. Mutations in the cardiac troponin I gene associated with hypertrophic cardiomyopathy. Nat Genet. 1997 Aug;16(4):379-82. PMID:9241277 doi:10.1038/ng0897-379
- ↑ Niimura H, Patton KK, McKenna WJ, Soults J, Maron BJ, Seidman JG, Seidman CE. Sarcomere protein gene mutations in hypertrophic cardiomyopathy of the elderly. Circulation. 2002 Jan 29;105(4):446-51. PMID:11815426
- ↑ Richard P, Charron P, Carrier L, Ledeuil C, Cheav T, Pichereau C, Benaiche A, Isnard R, Dubourg O, Burban M, Gueffet JP, Millaire A, Desnos M, Schwartz K, Hainque B, Komajda M. Hypertrophic cardiomyopathy: distribution of disease genes, spectrum of mutations, and implications for a molecular diagnosis strategy. Circulation. 2003 May 6;107(17):2227-32. Epub 2003 Apr 21. PMID:12707239 doi:10.1161/01.CIR.0000066323.15244.54
- ↑ Erdmann J, Daehmlow S, Wischke S, Senyuva M, Werner U, Raible J, Tanis N, Dyachenko S, Hummel M, Hetzer R, Regitz-Zagrosek V. Mutation spectrum in a large cohort of unrelated consecutive patients with hypertrophic cardiomyopathy. Clin Genet. 2003 Oct;64(4):339-49. PMID:12974739
- ↑ Ingles J, Doolan A, Chiu C, Seidman J, Seidman C, Semsarian C. Compound and double mutations in patients with hypertrophic cardiomyopathy: implications for genetic testing and counselling. J Med Genet. 2005 Oct;42(10):e59. PMID:16199542 doi:10.1136/jmg.2005.033886
- ↑ Mogensen J, Kubo T, Duque M, Uribe W, Shaw A, Murphy R, Gimeno JR, Elliott P, McKenna WJ. Idiopathic restrictive cardiomyopathy is part of the clinical expression of cardiac troponin I mutations. J Clin Invest. 2003 Jan;111(2):209-16. PMID:12531876 doi:10.1172/JCI16336
- ↑ Murphy RT, Mogensen J, Shaw A, Kubo T, Hughes S, McKenna WJ. Novel mutation in cardiac troponin I in recessive idiopathic dilated cardiomyopathy. Lancet. 2004 Jan 31;363(9406):371-2. PMID:15070570 doi:10.1016/S0140-6736(04)15468-8
- ↑ Lindhout DA, Sykes BD. Structure and dynamics of the C-domain of human cardiac troponin C in complex with the inhibitory region of human cardiac troponin I. J Biol Chem. 2003 Jul 18;278(29):27024-34. Epub 2003 May 5. PMID:12732641 doi:10.1074/jbc.M302497200
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