The Journal of General Physiology
Cell MicroControls
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
Published online
doi:10.1085/jgp.200709895
The Journal of General Physiology, Vol. 131, No. 3, 275-283
The Rockefeller University Press, 0022-1295 $30.00
© Terui et al.
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 2625K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JGP
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Terui, T.
Right arrow Articles by Fukuda, N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Terui, T.
Right arrow Articles by Fukuda, N.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

ARTICLE

 Troponin and Titin Coordinately Regulate Length-dependent Activation in Skinned Porcine Ventricular Muscle



Takako Terui1, Munguntsetseg Sodnomtseren1,2, Douchi Matsuba1, Jun Udaka1, Shin'ichi Ishiwata2, Iwao Ohtsuki1, Satoshi Kurihara1, and Norio Fukuda1

1 Department of Cell Physiology, The Jikei University School of Medicine, Tokyo 105-8461, Japan
2 Department of Physics, Waseda University, Tokyo 169-8555, Japan

Correspondence to Norio Fukuda: noriof{at}jikei.ac.jp; or Takako Terui: pu-cha{at}jikei.ac.jp

We investigated the molecular mechanism by which troponin (Tn) regulates the Frank-Starling mechanism of the heart. Quasi-complete reconstitution of thin filaments with rabbit fast skeletal Tn (sTn) attenuated length-dependent activation in skinned porcine left ventricular muscle, to a magnitude similar to that observed in rabbit fast skeletal muscle. The rate of force redevelopment increased upon sTn reconstitution at submaximal levels, coupled with an increase in Ca2+ sensitivity of force, suggesting the acceleration of cross-bridge formation and, accordingly, a reduction in the fraction of resting cross-bridges that can potentially produce additional active force. An increase in titin-based passive force, induced by manipulating the prehistory of stretch, enhanced length-dependent activation, in both control and sTn-reconstituted muscles. Furthermore, reconstitution of rabbit fast skeletal muscle with porcine left ventricular Tn enhanced length-dependent activation, accompanied by a decrease in Ca2+ sensitivity of force. These findings demonstrate that Tn plays an important role in the Frank-Starling mechanism of the heart via on–off switching of the thin filament state, in concert with titin-based regulation.

Abbreviations used in this paper: BDM, 2,3-butanedione monoxime; PLV, porcine left ventricular muscle; SL, sarcomere length; Tn, troponin.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:


Home page
 JGPHome page
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]


  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents