| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Faculty of Biology, University of Konstanz, D-78457 Konstanz, Germany
Fiber-type transitions in adult skeletal muscle induced by chronic low-frequency stimulation (CLFS) encompass coordinated exchanges of myofibrillar protein isoforms. CLFS-induced elevations in cytosolic Ca2+ could activate proteases, especially calpains, the major Ca2+-regulated cytosolic proteases. Calpain activity determined by a fluorogenic substrate in the presence of unaltered endogenous calpastatin activities increased twofold in low-frequency-stimulated extensor digitorum longus (EDL) muscle, reaching a level intermediate between normal fast- and slow-twitch muscles. µ- and m-calpains were delineated by a calpain-specific zymographical assay that assessed total activities independent of calpastatin and distinguished between native and processed calpains. Contrary to normal EDL, structure-bound, namely myofibrillar and microsomal calpains, were abundant in soleus muscle. However, the fast-to-slow conversion of EDL was accompanied by an early translocation of cytosolic µ-calpain, suggesting that myofibrillar and microsomal µ-calpain was responsible for the twofold increase in activity and thus involved in controlled proteolysis during fiber transformation. This is in contrast to muscle regeneration where m-calpain translocation predominated. Taken together, we suggest that translocation is an important step in the control of calpain activity in skeletal muscle in vivo.
calpain activation; calpastatin; chronic low-frequency stimulation; fast-to-slow transition; translocation
This article has been cited by other articles:
|
|
 |
|
  R. Scalia, Y. Gong, B. Berzins, L. J. Zhao, and K. Sharma Hyperglycemia Is a Major Determinant of Albumin Permeability in Diabetic Microcirculation: The Role of {micro}-Calpain Diabetes, July 1, 2007; 56(7): 1842 - 1849. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. J. Adhihetty, V. Ljubicic, and D. A. Hood Effect of chronic contractile activity on SS and IMF mitochondrial apoptotic susceptibility in skeletal muscle Am J Physiol Endocrinol Metab, March 1, 2007; 292(3): E748 - E755. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Bartoli, N. Bourg, D. Stockholm, F. Raynaud, A. Delevacque, Y. Han, P. Borel, K. Seddik, N. Armande, and I. Richard A Mouse Model for Monitoring Calpain Activity under Physiological and Pathological Conditions J. Biol. Chem., December 22, 2006; 281(51): 39672 - 39680. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Yang, B. Jemiolo, and S. Trappe Proteolytic mRNA expression in response to acute resistance exercise in human single skeletal muscle fibers J Appl Physiol, November 1, 2006; 101(5): 1442 - 1450. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. R. Sultan, B. Henkel, M. Terlou, and H. P. Haagsman Quantification of hormone-induced atrophy of large myotubes from C2C12 and L6 cells: atrophy-inducible and atrophy-resistant C2C12 myotubes Am J Physiol Cell Physiol, February 1, 2006; 290(2): C650 - C659. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. L Kim, R. S Staron, and S. M Phillips Fasted-state skeletal muscle protein synthesis after resistance exercise is altered with training J. Physiol., October 1, 2005; 568(1): 283 - 290. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Goette, M. Arndt, C. Rocken, T. Staack, R. Bechtloff, D. Reinhold, C. Huth, S. Ansorge, H. U. Klein, and U. Lendeckel Calpains and cytokines in fibrillating human atria Am J Physiol Heart Circ Physiol, July 1, 2002; 283(1): H264 - H272. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. R. Sultan, B. T. Dittrich, E. Leisner, N. Paul, and D. Pette Fiber type-specific expression of major proteolytic systems in fast- to slow-transforming rabbit muscle Am J Physiol Cell Physiol, February 1, 2001; 280(2): C239 - C247. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
