| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Pharmacology, The Pennsylvania State University, Hershey, PA, USA
2 Department of Medicine, Wayne State University, Detroit, MI, USA
3 Department of Integrative Physiology, University of Colorado, Boulder, CO, USA
* To whom correspondence should be addressed. E-mail: ycn1{at}psu.edu.
Phospholemman (PLM), a member of the FXYD family of proteins, is a recently identified accessory protein of the Na+,K+-ATPase (NKA) with a high
level of expression in skeletal muscle. Previously, we have demonstrated isoform-specific altered expression of the 
- and 
-subunit isoforms of the NKA in
skeletal muscle with age and after exercise training. The objectives of this study are to characterize the PLM in skeletal muscle and to test the hypothesis that, as
an accessory protein of the NKA, expression of PLM and its association with the -subunits of the NKA is also regulated during aging and with exercise training.
PLM was characterized in skeletal muscle of 6-month old and 16-month old sedentary middle-aged rats (Ms), and the effects of aging and exercise training was studied in Ms, 29-month old sedentary senescent (Ss), and 29-month old
treadmill exercised senescent (St) rats. Expression of PLM was muscle-type dependent, with extensor digitorum longus expressed higher levels and white gastrocnemius expressed lower levels. Immunofluorescence study showed that
PLM distributed predominantly on the sarcolemmal membrane of the muscle fibers. Anti-PLM antibody reduced activity of the NKA and thus PLM appears to be required for NKA to express its full activity in skeletal muscle. Expression of
PLM was not altered with aging but increased after exercise training. Coimmunoprecipitation
studies demonstrated that PLM associates with both the 1- and 2-subunit isoforms of the NKA. Compared to Ms rats, levels of PLMassociated
1-subunit increased in Ss rats and treadmill exercise has a tendency to partially reverse it. There was no significant change in PLM-associated 2-
subunit with age and exercise training has a tendency to increase that level. It is concluded that in skeletal muscle PLM appears to be a protein integral to the
NKA complex and that PLM has the potential to modulate the NKA in an isoformspecific and muscle-type dependent manner in aging and after exercise training.
This article has been cited by other articles:
|
|
 |
|
  D. Galuska, O. Kotova, R. Barres, D. Chibalina, B. Benziane, and A. V. Chibalin Altered expression and insulin-induced trafficking of Na+-K+-ATPase in rat skeletal muscle: effects of high-fat diet and exercise Am J Physiol Endocrinol Metab, July 1, 2009; 297(1): E38 - E49. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Juel Na+-K+-ATPase in rat skeletal muscle: muscle fiber-specific differences in exercise-induced changes in ion affinity and maximal activity Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2009; 296(1): R125 - R132. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Benziane and A. V. Chibalin Frontiers: Skeletal muscle sodium pump regulation: a translocation paradigm Am J Physiol Endocrinol Metab, September 1, 2008; 295(3): E553 - E558. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. J. Green, T. A. Duhamel, R. D. Stewart, A. R. Tupling, and J. Ouyang Dissociation between changes in muscle Na+-K+-ATPase isoform abundance and activity with consecutive days of exercise and recovery Am J Physiol Endocrinol Metab, April 1, 2008; 294(4): E761 - E767. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Arystarkhova, C. Donnet, A. Munoz-Matta, S. C. Specht, and K. J. Sweadner Multiplicity of expression of FXYD proteins in mammalian cells: dynamic exchange of phospholemman and {gamma}-subunit in response to stress Am J Physiol Cell Physiol, March 1, 2007; 292(3): C1179 - C1191. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
