HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Huang, Q.-Q. Articles by Jin, J.-P. Search for Related Content PubMed PubMed Citation Articles by Huang, Q.-Q. Articles by Jin, J.-P.

Fast skeletal muscle troponin T increases the cooperativity of transgenic mouse cardiac muscle contraction

Qi-Quan Huang, Frank V. Brozovich and Jian-Ping Jin

To investigate the functional significance of different troponin T (TnT) isoforms in the Ca²⁺ activation of muscle contraction, transgenic mice have been constructed with a chicken fast skeletal muscle TnT transgene driven by a cardiac -myosin heavy chain gene promoter.

Cardiac muscle-specific expression of the fast skeletal muscle TnT has been obtained with significant myofibril incorporation. Expression of the endogenous cardiac muscle thin filament regulatory proteins, such as troponin I and tropomyosin, was not altered in the transgenic mouse heart, providing an authentic system for the functional characterization of TnT isoforms.

Cardiac muscle contractility was analysed for the force vs. Ca²⁺ relationship in skinned ventricular trabeculae of transgenic mice in comparison with wild-type litter-mates. The results showed unchanged pCa₅₀ values (5·1 ± 0·04 and 5·1 ± 0·1, respectively) but significantly steeper slopes (the Hill coefficient was 2·0 ± 0·2 vs. 1·0 ± 0·2, P < 0·05).

The results demonstrate that the structural and functional variation of different TnT isoforms may contribute to the difference in responsiveness and overall cooperativity of the thin filament-based Ca²⁺ regulation between cardiac and skeletal muscles.

This article has been cited by other articles:

				Q.-Q. Huang, H. Z. Feng, J. Liu, J. Du, L. B. Stull, C. S. Moravec, X. Huang, and J.-P. Jin Co-expression of skeletal and cardiac troponin T decreases mouse cardiac function Am J Physiol Cell Physiol, January 1, 2008; 294(1): C213 - C222. [Abstract] [Full Text] [PDF]

				Z. B. Yu, F. Gao, H. Z. Feng, and J.-P. Jin Differential regulation of myofilament protein isoforms underlying the contractility changes in skeletal muscle unloading Am J Physiol Cell Physiol, March 1, 2007; 292(3): C1192 - C1203. [Abstract] [Full Text] [PDF]

				M. A. Brotto, B. J. Biesiadecki, L. S. Brotto, T. M. Nosek, and J.-P. Jin Coupled expression of troponin T and troponin I isoforms in single skeletal muscle fibers correlates with contractility Am J Physiol Cell Physiol, February 1, 2006; 290(2): C567 - C576. [Abstract] [Full Text] [PDF]

				J. C. Barbato, Q.-Q. Huang, M. M. Hossain, M. Bond, and J.-P. Jin Proteolytic N-terminal Truncation of Cardiac Troponin I Enhances Ventricular Diastolic Function J. Biol. Chem., February 25, 2005; 280(8): 6602 - 6609. [Abstract] [Full Text] [PDF]

				Y. M. Liou and J. C. H. Chang Differential pH Effect on Calcium-Induced Conformational Changes of Cardiac Troponin C Complexed with Cardiac and Fast Skeletal Isoforms of Troponin I and Troponin T J. Biochem., November 1, 2004; 136(5): 683 - 692. [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]

				J.-P. Jin, M. A. Brotto, M. M. Hossain, Q.-Q. Huang, L. S. Brotto, T. M. Nosek, D. H. Morton, and T. O. Crawford Truncation by Glu180 Nonsense Mutation Results in Complete Loss of Slow Skeletal Muscle Troponin T in a Lethal Nemaline Myopathy J. Biol. Chem., July 3, 2003; 278(28): 26159 - 26165. [Abstract] [Full Text] [PDF]

				B. J. Biesiadecki, B. D. Elder, Z.-B. Yu, and J.-P. Jin Cardiac Troponin T Variants Produced by Aberrant Splicing of Multiple Exons in Animals with High Instances of Dilated Cardiomyopathy J. Biol. Chem., December 20, 2002; 277(52): 50275 - 50285. [Abstract] [Full Text] [PDF]

				B. J. Biesiadecki and J.-P. Jin Exon Skipping in Cardiac Troponin T of Turkeys with Inherited Dilated Cardiomyopathy J. Biol. Chem., May 17, 2002; 277(21): 18459 - 18468. [Abstract] [Full Text] [PDF]

				K. Yamashita-Goto, R. Okuyama, M. Honda, K. Kawasaki, K. Fujita, T. Yamada, I. Nonaka, Y. Ohira, and T. Yoshioka Maximal and submaximal forces of slow fibers in human soleus after bed rest J Appl Physiol, July 1, 2001; 91(1): 417 - 424. [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]

				Z.-B. Yu, L.-F. Zhang, and J.-P. Jin A Proteolytic NH2-terminal Truncation of Cardiac Troponin I That Is Up-regulated in Simulated Microgravity J. Biol. Chem., May 4, 2001; 276(19): 15753 - 15760. [Abstract] [Full Text] [PDF]

				O. Ogut and J.-P. Jin Cooperative Interaction between Developmentally Regulated Troponin T and Tropomyosin Isoforms in the Absence of F-actin J. Biol. Chem., August 18, 2000; 275(34): 26089 - 26095. [Abstract] [Full Text] [PDF]

				P. VanBuren, S. L. Alix, J. A. Gorga, K. J. Begin, M. M. LeWinter, and N. R. Alpert Cardiac troponin T isoforms demonstrate similar effects on mechanical performance in a regulated contractile system Am J Physiol Heart Circ Physiol, May 1, 2002; 282(5): H1665 - H1671. [Abstract] [Full Text] [PDF]