| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Biophysical Journal 63: 460-468 (1992)
© 1992 the Biophysical Society
Department of Physiology, School of Medicine, University of Wisconsin, Madison 53706.
ABSTRACT
We investigated the mechanism of the Ca2+ sensitivity of cross-bridge transitions that limit the rate of force development in vertebrate skeletal muscle. The rate of force development increases with Ca2+ concentration in the physiological range. We show here that at low concentrations of Ca2+ the rate of force development increases after partial extraction of the 20-kD light chain 2 subunit of myosin, whereas reconstitution with light chain 2 fully restores native sensitivity to Ca2+ in skinned single skeletal fibers. Furthermore, elevated free Mg2+ concentration reduces Ca2+ sensitivity, an effect that is reversed by extraction of the light chain but not by disruption of thin-filament activation by partial removal of troponin C, the Ca2+ binding protein of the thin filament. Our findings indicate that the Ca2+ sensitivity of the rate of force development in vertebrate skeletal muscle is mediated in part by the light chain 2 subunit of the myosin cross-bridge.
This article has been cited by other articles:
 |
|
 |
|
  B. A. J. Baumann, H. Liang, K. Sale, B. D. Hambly, and P. G. Fajer Myosin Regulatory Domain Orientation in Skeletal Muscle Fibers: Application of Novel Electron Paramagnetic Resonance Spectral Decomposition and Molecular Modeling Methods Biophys. J., May 1, 2004; 86(5): 3030 - 3041. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. A. Callahan, Z. W. She, and T. M. Nosek Superoxide, hydroxyl radical, and hydrogen peroxide effects on single-diaphragm fiber contractile apparatus J Appl Physiol, January 1, 2001; 90(1): 45 - 54. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Danieli-Betto, E. Germinario, A. Esposito, D. Biral, and R. Betto Effects of fatigue on sarcoplasmic reticulum and myofibrillar properties of rat single muscle fibers J Appl Physiol, September 1, 2000; 89(3): 891 - 898. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Gordon, E. Homsher, and M. Regnier Regulation of Contraction in Striated Muscle Physiol Rev, April 1, 2000; 80(2): 853 - 924. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. J. Baker, V. M. Figueredo, E. C. Keung, and S. A. Camacho Ca2+ regulates the kinetics of tension development in intact cardiac muscle Am J Physiol Heart Circ Physiol, September 1, 1998; 275(3): H744 - H750. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Gulick, T. E. Hewett, R. Klevitsky, S. H. Buck, R. L. Moss, and J. Robbins Transgenic Remodeling of the Regulatory Myosin Light Chains in the Mammalian Heart Circ. Res., May 19, 1997; 80(5): 655 - 664. [Abstract] [Full Text]
|
|
|
|
 |
|
 D. Szczesna, J. Zhao, and J. D. Potter The Regulatory Light Chains of Myosin Modulate Cross-bridge Cycling in Skeletal Muscle J. Biol. Chem., March 1, 1996; 271(9): 5246 - 5250. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Palermo, J. Gulick, M. Colbert, J. Fewell, and J. Robbins Transgenic Remodeling of the Contractile Apparatus in the Mammalian Heart Circ. Res., March 1, 1996; 78(3): 504 - 509. [Abstract] [Full Text]
|
|
|
|
|
|
J. M. Metzger, W.-I. Lin, R. A. Johnston, M. V. Westfall, and L. C. Samuelson Myosin Heavy Chain Expression in Contracting Myocytes Isolated During Embryonic Stem Cell Cardiogenesis Circ. Res., May 1, 1995; 76(5): 710 - 719. [Abstract] [Full Text]
|
|
|
|
|
|
D. Szczesna, J. Zhao, M. Jones, G. Zhi, J. Stull, and J. D. Potter Phosphorylation of the regulatory light chains of myosin affects Ca2+ sensitivity of skeletal muscle contraction J Appl Physiol, April 1, 2002; 92(4): 1661 - 1670. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
