Troponin and Tropomyosin

Proteins That Switch on and Tune in the Activity of Cardiac Myofilaments

From the Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago.

Correspondence to R. John Solaro, PhD, Department of Physiology and Biophysics (M/C 901), College of Medicine, University of Illinois at Chicago, 835 South Wolcott Ave, Chicago, IL 60612-7342.

Abstract—We present a current perception of the regulation of activation of cardiac myofilaments with emphasis on troponin (Tn) and tropomyosin (Tm). Activation involves both a Ca²⁺-regulated molecular switch and a potentiated state, dependent on feedback effects of force-generating crossbridges. Recent developments in the elucidation of the structure and arrangement of the myofilament proteins offer insights into the molecular interactions that constitute the switching and potentiating mechanisms. Transgenic mice overexpressing myofilament proteins, in vitro studies of mutant myofilament proteins, multidimensional multinuclear nuclear magnetic resonance, and fluorescence resonance energy transfer offer important approaches to understanding the molecular signaling processes. These studies reveal special features of the cardiac myofilament proteins that appear specialized for the unique functions of the heart. An important aspect of these special features is their role in mechanical, chemical, and neurohumoral coupling processes that tune myofilament activation to hemodynamics and beating frequency. Understanding these processes has become essential to understanding cardiac pathologies such as heart failure, ischemia and reperfusion injury, stunning, and familial hypertrophic cardiac myopathies.

Key Words: heart • thin filament • myosin • actin • Ca²⁺ binding protein

This article has been cited by other articles:

				D. Matsuba, T. Terui, J. O-Uchi, H. Tanaka, T. Ojima, I. Ohtsuki, S. Ishiwata, S. Kurihara, and N. Fukuda Protein kinase A-dependent modulation of Ca2+ sensitivity in cardiac and fast skeletal muscles after reconstitution with cardiac troponin J. Gen. Physiol., June 1, 2009; 133(6): 571 - 581. [Abstract] [Full Text] [PDF]

				S. B. Scruggs, A. C. Hinken, A. Thawornkaiwong, J. Robbins, L. A. Walker, P. P. de Tombe, D. L. Geenen, P. M. Buttrick, and R. J. Solaro Ablation of Ventricular Myosin Regulatory Light Chain Phosphorylation in Mice Causes Cardiac Dysfunction in Situ and Affects Neighboring Myofilament Protein Phosphorylation J. Biol. Chem., February 20, 2009; 284(8): 5097 - 5106. [Abstract] [Full Text] [PDF]

				V. Zabrouskov, Y. Ge, J. Schwartz, and J. W. Walker Unraveling Molecular Complexity of Phosphorylated Human Cardiac Troponin I by Top Down Electron Capture Dissociation/Electron Transfer Dissociation Mass Spectrometry Mol. Cell. Proteomics, October 1, 2008; 7(10): 1838 - 1849. [Abstract] [Full Text] [PDF]

				Y. Wen, J. R. Pinto, A. V. Gomes, Y. Xu, Y. Wang, Y. Wang, J. D. Potter, and W. G. L. Kerrick Functional Consequences of the Human Cardiac Troponin I Hypertrophic Cardiomyopathy Mutation R145G in Transgenic Mice J. Biol. Chem., July 18, 2008; 283(29): 20484 - 20494. [Abstract] [Full Text] [PDF]

				T. Terui, M. Sodnomtseren, D. Matsuba, J. Udaka, S. Ishiwata, I. Ohtsuki, S. Kurihara, and N. Fukuda Troponin and Titin Coordinately Regulate Length-dependent Activation in Skinned Porcine Ventricular Muscle J. Gen. Physiol., February 25, 2008; 131(3): 275 - 283. [Abstract] [Full Text] [PDF]

				G. M. Kravtsov, K. W. L. Kam, J. Liu, S. Wu, and T. M. Wong Altered Ca2+ handling by ryanodine receptor and Na+-Ca2+ exchange in the heart from ovariectomized rats: role of protein kinase A Am J Physiol Cell Physiol, May 1, 2007; 292(5): C1625 - C1635. [Abstract] [Full Text] [PDF]

				O. M. Hernandez, M. Jones, G. Guzman, and D. Szczesna-Cordary Myosin essential light chain in health and disease Am J Physiol Heart Circ Physiol, April 1, 2007; 292(4): H1643 - H1654. [Abstract] [Full Text] [PDF]

				J. E. Stelzer, J. R. Patel, and R. L. Moss Protein Kinase A-Mediated Acceleration of the Stretch Activation Response in Murine Skinned Myocardium Is Eliminated by Ablation of cMyBP-C Circ. Res., October 13, 2006; 99(8): 884 - 890. [Abstract] [Full Text] [PDF]

				M. Adamcova, M. Sterba, T. Simunek, A. Potacova, O. Popelova, and V. Gersl Myocardial regulatory proteins and heart failure Eur J Heart Fail, June 1, 2006; 8(4): 333 - 342. [Abstract] [Full Text] [PDF]

				L. Pereira, J. Matthes, I. Schuster, H. H. Valdivia, S. Herzig, S. Richard, and A. M. Gomez Mechanisms of [Ca2+]i Transient Decrease in Cardiomyopathy of db/db Type 2 Diabetic Mice Diabetes, March 1, 2006; 55(3): 608 - 615. [Abstract] [Full Text] [PDF]

				R. P. Kondo, D. A. Dederko, C. Teutsch, J. Chrast, D. Catalucci, K. R. Chien, and W. R. Giles Comparison of contraction and calcium handling between right and left ventricular myocytes from adult mouse heart: a role for repolarization waveform J. Physiol., February 15, 2006; 571(1): 131 - 146. [Abstract] [Full Text] [PDF]

				O. Cazorla, S. Szilagyi, N. Vignier, G. Salazar, E. Kramer, G. Vassort, L. Carrier, and A. Lacampagne Length and protein kinase A modulations of myocytes in cardiac myosin binding protein C-deficient mice Cardiovasc Res, February 1, 2006; 69(2): 370 - 380. [Abstract] [Full Text] [PDF]

				M. Chandra, M. L. Tschirgi, and J. C. Tardiff Increase in tension-dependent ATP consumption induced by cardiac troponin T mutation Am J Physiol Heart Circ Physiol, November 1, 2005; 289(5): H2112 - H2119. [Abstract] [Full Text] [PDF]

				E. W. Clemmens, M. Entezari, D. A Martyn, and M. Regnier Different effects of cardiac versus skeletal muscle regulatory proteins on in vitro measures of actin filament speed and force J. Physiol., August 1, 2005; 566(3): 737 - 746. [Abstract] [Full Text] [PDF]

				G. Sawicki, H. Leon, J. Sawicka, M. Sariahmetoglu, C. J. Schulze, P. G. Scott, D. Szczesna-Cordary, and R. Schulz Degradation of Myosin Light Chain in Isolated Rat Hearts Subjected to Ischemia-Reperfusion Injury: A New Intracellular Target for Matrix Metalloproteinase-2 Circulation, July 26, 2005; 112(4): 544 - 552. [Abstract] [Full Text] [PDF]

				S. Itoh, B. Ding, C. P. Bains, N. Wang, Y. Takeishi, T. Jalili, G. L. King, R. A. Walsh, C. Yan, and J.-i. Abe Role of p90 Ribosomal S6 Kinase (p90RSK) in Reactive Oxygen Species and Protein Kinase C {beta} (PKC-{beta})-mediated Cardiac Troponin I Phosphorylation J. Biol. Chem., June 24, 2005; 280(25): 24135 - 24142. [Abstract] [Full Text] [PDF]

				A.J. Marian On Mice, Rabbits, and Human Heart Failure Circulation, May 10, 2005; 111(18): 2276 - 2279. [Full Text] [PDF]

				S. Eriksson, H. Halenius, K. Pulkki, J. Hellman, and K. Pettersson Negative Interference in Cardiac Troponin I Immunoassays by Circulating Troponin Autoantibodies Clin. Chem., May 1, 2005; 51(5): 839 - 847. [Abstract] [Full Text] [PDF]

				V. Sarin, R. D Gaffin, G. A Meininger, and M. Muthuchamy Arginine-glycine-aspartic acid (RGD)-containing peptides inhibit the force production of mouse papillary muscle bundles via {alpha}5{beta}1 integrin J. Physiol., April 15, 2005; 564(2): 603 - 617. [Abstract] [Full Text] [PDF]

				M Kruger, S Zittrich, C Redwood, N Blaudeck, J James, J Robbins, G Pfitzer, and R Stehle Effects of the mutation R145G in human cardiac troponin I on the kinetics of the contraction-relaxation cycle in isolated cardiac myofibrils J. Physiol., April 15, 2005; 564(2): 347 - 357. [Abstract] [Full Text] [PDF]

				J. Layland, R. J. Solaro, and A. M. Shah Regulation of cardiac contractile function by troponin I phosphorylation Cardiovasc Res, April 1, 2005; 66(1): 12 - 21. [Abstract] [Full Text] [PDF]

				J. van der Velden, D. Merkus, B.R. Klarenbeek, A.T. James, N.M. Boontje, D.H.W. Dekkers, G.J.M. Stienen, J.M.J. Lamers, and D.J. Duncker Alterations in Myofilament Function Contribute to Left Ventricular Dysfunction in Pigs Early After Myocardial Infarction Circ. Res., November 26, 2004; 95(11): e85 - e95. [Abstract] [Full Text]

				J. Mogensen, R. T. Murphy, T. Shaw, A. Bahl, C. Redwood, H. Watkins, M. Burke, P. M. Elliott, and W. J. McKenna Severe disease expression of cardiac troponin C and T mutations in patients with idiopathic dilated cardiomyopathy J. Am. Coll. Cardiol., November 16, 2004; 44(10): 2033 - 2040. [Abstract] [Full Text] [PDF]

				J. E. Stelzer, J. R. Patel, M. C. Olsson, D. P. Fitzsimons, L. A. Leinwand, and R. L. Moss Expression of cardiac troponin T with COOH-terminal truncation accelerates cross-bridge interaction kinetics in mouse myocardium Am J Physiol Heart Circ Physiol, October 1, 2004; 287(4): H1756 - H1761. [Abstract] [Full Text] [PDF]

				P. S. Villars, S. K. Hamlin, A. D. Shaw, and J. T. Kanusky Role of Diastole in Left Ventricular Function, I: Biochemical and Biomechanical Events Am. J. Crit. Care., September 1, 2004; 13(5): 394 - 403. [Abstract] [Full Text] [PDF]

				T. Noguchi, M. Hunlich, P. C. Camp, K. J. Begin, M. El-Zaru, R. Patten, B. J. Leavitt, F. P. Ittleman, N. R. Alpert, M. M. LeWinter, et al. Thin Filament-Based Modulation of Contractile Performance in Human Heart Failure Circulation, August 24, 2004; 110(8): 982 - 987. [Abstract] [Full Text] [PDF]

				H. BARTSCH, S. VOIGTSBERGER, G. BAUMANN, I. MORANO, and H. P. LUTHER Detection of a novel sense-antisense RNA-hybrid structure by RACE experiments on endogenous troponin I antisense RNA RNA, August 1, 2004; 10(8): 1215 - 1224. [Abstract] [Full Text] [PDF]

				C. W. Tong, R. D. Gaffin, D. C. Zawieja, and M. Muthuchamy Roles of phosphorylation of myosin binding protein-C and troponin I in mouse cardiac muscle twitch dynamics J. Physiol., August 1, 2004; 558(3): 927 - 941. [Abstract] [Full Text] [PDF]

				D. A Colantonio, J. E Van Eyk, and K. Przyklenk Stunned peri-infarct canine myocardium is characterized by degradation of troponin T, not troponin I Cardiovasc Res, August 1, 2004; 63(2): 217 - 225. [Abstract] [Full Text] [PDF]

				R. L. Moss, M. Razumova, and D. P. Fitzsimons Myosin Crossbridge Activation of Cardiac Thin Filaments: Implications for Myocardial Function in Health and Disease Circ. Res., May 28, 2004; 94(10): 1290 - 1300. [Abstract] [Full Text] [PDF]

				B. J. Biesiadecki, K. L. Schneider, Z.-B. Yu, S. M. Chong, and J.-P. Jin An R111C Polymorphism in Wild Turkey Cardiac Troponin I Accompanying the Dilated Cardiomyopathy-related Abnormal Splicing Variant of Cardiac Troponin T with Potentially Compensatory Effects J. Biol. Chem., April 2, 2004; 279(14): 13825 - 13832. [Abstract] [Full Text] [PDF]

				E. Takimoto, D. G. Soergel, P. M.L. Janssen, L. B. Stull, D. A. Kass, and A. M. Murphy Frequency- and Afterload-Dependent Cardiac Modulation In Vivo by Troponin I With Constitutively Active Protein Kinase A Phosphorylation Sites Circ. Res., March 5, 2004; 94(4): 496 - 504. [Abstract] [Full Text] [PDF]

				M. P. Sumandea, W. G. Pyle, T. Kobayashi, P. P. de Tombe, and R. J. Solaro Identification of a Functionally Critical Protein Kinase C Phosphorylation Residue of Cardiac Troponin T J. Biol. Chem., September 12, 2003; 278(37): 35135 - 35144. [Abstract] [Full Text] [PDF]

				J. Kohler, Y. Chen, B. Brenner, A. M. Gordon, T. Kraft, D. A. Martyn, M. Regnier, A. J. Rivera, C.-K. Wang, and P. B. Chase Familial hypertrophic cardiomyopathy mutations in troponin I (K183{Delta}, G203S, K206Q) enhance filament sliding Physiol Genomics, July 7, 2003; 14(2): 117 - 128. [Abstract] [Full Text] [PDF]

				S. Eriksson, M. Junikka, P. Laitinen, K. Majamaa-Voltti, H. Alfthan, and K. Pettersson Negative Interference in Cardiac Troponin I Immunoassays from a Frequently Occurring Serum and Plasma Component Clin. Chem., July 1, 2003; 49(7): 1095 - 1104. [Abstract] [Full Text] [PDF]

				J. P Konhilas, T. C Irving, B. M Wolska, E. E Jweied, A. F Martin, R John Solaro, and P. P de Tombe Troponin I in the murine myocardium: influence on length-dependent activation and interfilament spacing J. Physiol., March 15, 2003; 547(3): 951 - 961. [Abstract] [Full Text] [PDF]

				S. R. Houser and K. B. Margulies Is Depressed Myocyte Contractility Centrally Involved in Heart Failure? Circ. Res., March 7, 2003; 92(4): 350 - 358. [Abstract] [Full Text] [PDF]

				W.-J. Dong, J. M. Robinson, S. Stagg, J. Xing, and H. C. Cheung Ca2+-induced Conformational Transition in the Inhibitory and Regulatory Regions of Cardiac Troponin I J. Biol. Chem., February 28, 2003; 278(10): 8686 - 8692. [Abstract] [Full Text] [PDF]

				J. P Konhilas, T. C Irving, and P. P de Tombe Length-dependent activation in three striated muscle types of the rat J. Physiol., October 1, 2002; 544(1): 225 - 236. [Abstract] [Full Text] [PDF]

				W. Wang, C. J. Schulze, W. L. Suarez-Pinzon, J. R.B. Dyck, G. Sawicki, and R. Schulz Intracellular Action of Matrix Metalloproteinase-2 Accounts for Acute Myocardial Ischemia and Reperfusion Injury Circulation, September 17, 2002; 106(12): 1543 - 1549. [Abstract] [Full Text] [PDF]

				X. Wang, M. X. Li, and B. D. Sykes Structure of the Regulatory N-domain of Human Cardiac Troponin C in Complex with Human Cardiac Troponin I147-163 and Bepridil J. Biol. Chem., August 16, 2002; 277(34): 31124 - 31133. [Abstract] [Full Text] [PDF]

				W. G. Pyle, M. C. Hart, J. A. Cooper, M. P. Sumandea, P. P. de Tombe, and R. J. Solaro Actin Capping Protein: An Essential Element in Protein Kinase Signaling to the Myofilaments Circ. Res., June 28, 2002; 90(12): 1299 - 1306. [Abstract] [Full Text] [PDF]

				O. Zeitz, A. E. Maass, P. Van Nguyen, G. Hensmann, H. Kogler, K. Moller, G. Hasenfuss, and P. M.L. Janssen Hydroxyl Radical-Induced Acute Diastolic Dysfunction Is Due to Calcium Overload via Reverse-Mode Na+-Ca2+ Exchange Circ. Res., May 17, 2002; 90(9): 988 - 995. [Abstract] [Full Text] [PDF]

				B. M. Wolska, G. M. Arteaga, J. R. Pena, G. Nowak, R. M. Phillips, S. Sahai, P. P. de Tombe, A. F. Martin, E. G. Kranias, and R. J. Solaro Expression of Slow Skeletal Troponin I in Hearts of Phospholamban Knockout Mice Alters the Relaxant Effect of {beta}-Adrenergic Stimulation Circ. Res., May 3, 2002; 90(8): 882 - 888. [Abstract] [Full Text] [PDF]

				A. MAASS, J.P. KONHILAS, B.L. STAUFFER, and L.A. LEINWAND From Sarcomeric Mutations to Heart Disease: Understanding Familial Hypertrophic Cardiomyopathy Cold Spring Harb Symp Quant Biol, January 1, 2002; 67(0): 409 - 416. [Abstract] [PDF]

				G. A. MacGowan, C. Du, D. F. Wieczorek, and A. P. Koretsky Compensatory changes in Ca2+ and myocardial O2 consumption in beta -tropomyosin transgenic hearts Am J Physiol Heart Circ Physiol, December 1, 2001; 281(6): H2539 - H2548. [Abstract] [Full Text] [PDF]

				J. An, S. G. Varadarajan, E. Novalija, and D. F. Stowe Ischemic and anesthetic preconditioning reduces cytosolic [Ca2+] and improves Ca2+ responses in intact hearts Am J Physiol Heart Circ Physiol, October 1, 2001; 281(4): H1508 - H1523. [Abstract] [Full Text] [PDF]

				P. Boknik, I. Heinroth-Hoffmann, U. Kirchhefer, J. Knapp, B. Linck, H. Luss, T. Muller, W. Schmitz, O.-E. Brodde, and J. Neumann Enhanced protein phosphorylation in hypertensive hypertrophy Cardiovasc Res, September 1, 2001; 51(4): 717 - 728. [Abstract] [Full Text] [PDF]

				J. R. Patel, D. P. Fitzsimons, S. H. Buck, M. Muthuchamy, D. F. Wieczorek, and R. L. Moss PKA accelerates rate of force development in murine skinned myocardium expressing {alpha}- or {beta}-tropomyosin Am J Physiol Heart Circ Physiol, June 1, 2001; 280(6): H2732 - H2739. [Abstract] [Full Text] [PDF]

				S. Baudet, J. Weisser, A. P Janssen, K. Beulich, U. Bieligk, B. Pieske, J. Noireaud, P. M.L Janssen, G. Hasenfuss, and J. Prestle Increased basal contractility of cardiomyocytes overexpressing protein kinase C{epsilon} and blunted positive inotropic response to endothelin-1 Cardiovasc Res, June 1, 2001; 50(3): 486 - 494. [Abstract] [Full Text] [PDF]

				L. Huang, B. M. Wolska, D. E. Montgomery, E. M. Burkart, P. M. Buttrick, and R. J. Solaro Increased contractility and altered Ca2+ transients of mouse heart myocytes conditionally expressing PKC{beta} Am J Physiol Cell Physiol, May 1, 2001; 280(5): C1114 - C1120. [Abstract] [Full Text] [PDF]

				A. M. Gordon, M. Regnier, and E. Homsher Skeletal and Cardiac Muscle Contractile Activation: Tropomyosin "Rocks and Rolls" Physiology, April 1, 2001; 16(2): 49 - 55. [Abstract] [Full Text] [PDF]

				D. E. Montgomery, M. Chandra, Q.-Q. Huang, J.-P. Jin, and R. J. Solaro Transgenic incorporation of skeletal TnT into cardiac myofilaments blunts PKC-mediated depression of force Am J Physiol Heart Circ Physiol, March 1, 2001; 280(3): H1011 - H1018. [Abstract] [Full Text] [PDF]

				F. Fuchs and S. H. Smith Calcium, Cross-Bridges, and the Frank-Starling Relationship Physiology, February 1, 2001; 16(1): 5 - 10. [Abstract] [Full Text] [PDF]

				M. Chandra, V. L. M. Rundell, J. C. Tardiff, L. A. Leinwand, P. P. de Tombe, and R. J. Solaro Ca2+ activation of myofilaments from transgenic mouse hearts expressing R92Q mutant cardiac troponin T Am J Physiol Heart Circ Physiol, February 1, 2001; 280(2): H705 - H713. [Abstract] [Full Text] [PDF]

				D. P Fitzsimons, J. R Patel, and R. L Moss Cross-bridge interaction kinetics in rat myocardium are accelerated by strong binding of myosin to the thin filament J. Physiol., January 15, 2001; 530(2): 263 - 272. [Abstract] [Full Text] [PDF]

				G. Esposito, L. F. Santana, K. Dilly, J. D. S. Cruz, L. Mao, W. J. Lederer, and H. A. Rockman Cellular and functional defects in a mouse model of heart failure Am J Physiol Heart Circ Physiol, December 1, 2000; 279(6): H3101 - H3112. [Abstract] [Full Text] [PDF]

				C. C. Evans, J. R. Pena, R. M. Phillips, M. Muthuchamy, D. F. Wieczorek, R. J. Solaro, and B. M. Wolska Altered hemodynamics in transgenic mice harboring mutant tropomyosin linked to hypertrophic cardiomyopathy Am J Physiol Heart Circ Physiol, November 1, 2000; 279(5): H2414 - H2423. [Abstract] [Full Text] [PDF]

				K. S. McDonald and R. L. Moss Strongly Binding Myosin Crossbridges Regulate Loaded Shortening and Power Output in Cardiac Myocytes Circ. Res., October 27, 2000; 87(9): 768 - 773. [Abstract] [Full Text] [PDF]

				J. James, Y. Zhang, H. Osinska, A. Sanbe, R. Klevitsky, T. E. Hewett, and J. Robbins Transgenic Modeling of a Cardiac Troponin I Mutation Linked to Familial Hypertrophic Cardiomyopathy Circ. Res., October 27, 2000; 87(9): 805 - 811. [Abstract] [Full Text] [PDF]

				G. M Arteaga, K. A Palmiter, J. M Leiden, and R J. Solaro Attenuation of length dependence of calcium activation in myofilaments of transgenic mouse hearts expressing slow skeletal troponin I J. Physiol., August 1, 2000; 526(3): 541 - 549. [Abstract] [Full Text] [PDF]

				B. H. Lorell and B. A. Carabello Left Ventricular Hypertrophy : Pathogenesis, Detection, and Prognosis Circulation, July 25, 2000; 102(4): 470 - 479. [Full Text] [PDF]

				J. van der Velden, J.W. de Jong, V.J. Owen, P.B.J. Burton, and G.J.M. Stienen Effect of protein kinase A on calcium sensitivity of force and its sarcomere length dependence in human cardiomyocytes Cardiovasc Res, June 1, 2000; 46(3): 487 - 495. [Abstract] [Full Text] [PDF]

				R. L. Moss and J. S.’A. Periera Enhanced Myosin Function Due to a Point Mutation Causing a Familial Hypertrophic Cardiomyopathy Circ. Res., April 14, 2000; 86(7): 720 - 722. [Full Text] [PDF]

				B. Russell, D. Motlagh, and W. W. Ashley Form follows function: how muscle shape is regulated by work J Appl Physiol, March 1, 2000; 88(3): 1127 - 1132. [Abstract] [Full Text] [PDF]

				A. Xu and N. Narayanan Reversible Inhibition of the Calcium-pumping ATPase in Native Cardiac Sarcoplasmic Reticulum by a Calmodulin-binding Peptide. EVIDENCE FOR CALMODULIN-DEPENDENT REGULATION OF THE Vmax OF CALCIUM TRANSPORT J. Biol. Chem., February 11, 2000; 275(6): 4407 - 4416. [Abstract] [Full Text] [PDF]

				J. H. Marden, G. H. Fitzhugh, M. R. Wolf, K. D. Arnold, and B. Rowan From the Cover: Alternative splicing, muscle calcium sensitivity, and the modulation of dragonfly flight performance PNAS, December 21, 1999; 96(26): 15304 - 15309. [Abstract] [Full Text] [PDF]

				A. C. Fox and R. I. Levin Ruptured Plaques and Leaking Cells: Cost-Effectiveness in the Diagnosis of Acute Coronary Syndromes Ann Intern Med, December 21, 1999; 131(12): 968 - 970. [Full Text] [PDF]

				D. B. Foster and J. E. Van Eyk In Search of the Proteins That Cause Myocardial Stunning Circ. Res., September 3, 1999; 85(5): 470 - 472. [Full Text] [PDF]

				P. J Hanley, A. A Young, I. J LeGrice, S. G Edgar, and D. S Loiselle 3-Dimensional configuration of perimysial collagen fibres in rat cardiac muscle at resting and extended sarcomere lengths J. Physiol., June 15, 1999; 517(3): 831 - 837. [Abstract] [Full Text] [PDF]

				V. Gaponenko, E. Abusamhadneh, M. B. Abbott, N. Finley, G. Gasmi-Seabrook, R. J. Solaro, M. Rance, and P. R. Rosevear Effects of Troponin I Phosphorylation on Conformational Exchange in the Regulatory Domain of Cardiac Troponin C J. Biol. Chem., June 11, 1999; 274(24): 16681 - 16684. [Abstract] [Full Text] [PDF]

				R. C Fentzke, S. H Buck, J. R Patel, H. Lin, B. M Wolska, M. O Stojanovic, A. F Martin, R J. Solaro, R. L Moss, and J. M Leiden Impaired cardiomyocyte relaxation and diastolic function in transgenic mice expressing slow skeletal troponin I in the heart J. Physiol., May 15, 1999; 517(1): 143 - 157. [Abstract] [Full Text] [PDF]

				B. M. Wolska, R. S. Keller, C. C. Evans, K. A. Palmiter, R. M. Phillips, M. Muthuchamy, J. Oehlenschlager, D. F. Wieczorek, P. P. de Tombe, and R. J. Solaro Correlation Between Myofilament Response to Ca2+ and Altered Dynamics of Contraction and Relaxation in Transgenic Cardiac Cells That Express ß-Tropomyosin Circ. Res., April 16, 1999; 84(7): 745 - 751. [Abstract] [Full Text] [PDF]

				R. L. Moss Plasticity in the Dynamics of Myocardial Contraction : Ca2+, Crossbridge Kinetics, or Molecular Cooperation Circ. Res., April 16, 1999; 84(7): 862 - 865. [Full Text] [PDF]

				R. J. Solaro Troponin I, Stunning, Hypertrophy, and Failure of the Heart Circ. Res., January 22, 1999; 84(1): 122 - 124. [Full Text] [PDF]

				J. R. Pearlstone, M. Chandra, M. M. Sorenson, and L. B. Smillie Biological Function and Site II Ca2+-induced Opening of the Regulatory Domain of Skeletal Troponin C Are Impaired by Invariant Site I or II Glu Mutations J. Biol. Chem., November 3, 2000; 275(45): 35106 - 35115. [Abstract] [Full Text] [PDF]

				K. Elliott, H. Watkins, and C. S. Redwood Altered Regulatory Properties of Human Cardiac Troponin I Mutants That Cause Hypertrophic Cardiomyopathy J. Biol. Chem., July 14, 2000; 275(29): 22069 - 22074. [Abstract] [Full Text] [PDF]

				X. Wang, M. X. Li, L. Spyracopoulos, N. Beier, M. Chandra, R. J. Solaro, and B. D. Sykes Structure of the C-domain of Human Cardiac Troponin C in Complex with the Ca2+ Sensitizing Drug EMD 57033 J. Biol. Chem., June 29, 2001; 276(27): 25456 - 25466. [Abstract] [Full Text] [PDF]

				M. B. Abbott, V. Gaponenko, E. Abusamhadneh, N. Finley, G. Li, A. Dvoretsky, M. Rance, R. J. Solaro, and P. R. Rosevear Regulatory Domain Conformational Exchange and Linker Region Flexibility in Cardiac Troponin C Bound to Cardiac Troponin I J. Biol. Chem., June 30, 2000; 275(27): 20610 - 20617. [Abstract] [Full Text] [PDF]

				S.-J. Kim, R. K. Kudej, A. Yatani, Y.-K. Kim, G. Takagi, R. Honda, D. A. Colantonio, J. E. Van Eyk, D. E. Vatner, R. L. Rasmusson, et al. A Novel Mechanism for Myocardial Stunning Involving Impaired Ca2+ Handling Circ. Res., October 26, 2001; 89(9): 831 - 837. [Abstract] [Full Text] [PDF]

				B. M. Wolska, G. M. Arteaga, J. R. Pena, G. Nowak, R. M. Phillips, S. Sahai, P. P. de Tombe, A. F. Martin, E. G. Kranias, and R. J. Solaro Expression of Slow Skeletal Troponin I in Hearts of Phospholamban Knockout Mice Alters the Relaxant Effect of {beta}-Adrenergic Stimulation Circ. Res., May 3, 2002; 90(8): 882 - 888. [Abstract] [Full Text] [PDF]