AJP - Endo Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Am J Physiol Endocrinol Metab (June 6, 2006). doi:10.1152/ajpendo.00069.2006
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
291/4/E849    most recent
00069.2006v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Suryawan, A.
Right arrow Articles by Davis, T. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Suryawan, A.
Right arrow Articles by Davis, T. A.
Submitted on February 8, 2006
Accepted on May 25, 2006

Developmental Regulation of the Activation of Signaling Components Leading to Translation Initiation in Skeletal Muscle of Neonatal Pigs

Agus Suryawan1, Jeffery Escobar1, Jason W. Frank1, Hanh V. Nguyen1, and Teresa A. Davis1*

1 Department of Pediatrics, United States Department Agriculture/Agriculture Research Service, Children's Nutrition Research Center, Baylor College of Medi, Houston, Texas, United States

* To whom correspondence should be addressed. E-mail: tdavis{at}bcm.edu.

The rapid growth of neonates is driven by high rates of skeletal muscle protein synthesis. This high rate of protein synthesis, which is induced by feeding, declines with development. Overnight fasted, 7- and 26-day-old pigs either remained fasting or were refed and the abundance and phosphorylation of growth factor- and nutrient-induced signaling components that regulate mRNA translation initiation were measured in skeletal muscle and liver. In muscle, but not liver, the activation of inhibitors of protein synthesis, phosphatase and tensin homologue deleted on chromosome 10 (PTEN), protein phosphatase 2A (PP2A), and tuberous sclerosis complex 1/2 (TSC1/2) increased with age. Ser/Thr phosphorylation of the insulin receptor (IR) and insulin receptor substrate 1 (IRS-1), which down-regulates insulin signaling, and the activation of AMP-activated protein kinase (AMPK), an inhibitor of protein synthesis, were unaffected by age and feeding in muscle and liver. Activation of positive regulators of protein synthesis, mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase 1 (S6K1), and eIF-4E binding protein-1 (4E-BP1), decreased with age in muscle but not liver. Feeding enhanced mTOR, S6K1, and 4E-BP1 activation in muscle, and this response decreased with age. In liver, activation of S6K1 and 4E-BP1, but not mTOR, was increased by feeding but was unaffected by age. Raptor abundance and the association between raptor and mTOR were greater in 7- than in 26-day-old pigs. The results suggest the developmental decline in skeletal muscle protein synthesis is due in part to developmental regulation of the activation of growth factor and nutrient signaling components.




This article has been cited by other articles:


Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
F. A. Wilson, R. A. Orellana, A. Suryawan, H. V. Nguyen, A. S. Jeyapalan, J. Frank, and T. A. Davis
Stimulation of muscle protein synthesis by somatotropin in pigs is independent of the somatotropin-induced increase in circulating insulin
Am J Physiol Endocrinol Metab, July 1, 2008; 295(1): E187 - E194.
[Abstract] [Full Text] [PDF]

Home page
 J DAIRY SCIHome page
G. I. Zanton and A. J. Heinrichs
Analysis of Nitrogen Utilization and Excretion in Growing Dairy Cattle
J Dairy Sci, April 1, 2008; 91(4): 1519 - 1533.
[Abstract] [Full Text] [PDF]

Home page
 J. Nutr.Home page
J. Wang, L. Chen, D. Li, Y. Yin, X. Wang, P. Li, L. J. Dangott, W. Hu, and G. Wu
Intrauterine Growth Restriction Affects the Proteomes of the Small Intestine, Liver, and Skeletal Muscle in Newborn Pigs
J. Nutr., January 1, 2008; 138(1): 60 - 66.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
J. Escobar, J. W. Frank, A. Suryawan, H. V. Nguyen, and T. A. Davis
Amino acid availability and age affect the leucine stimulation of protein synthesis and eIF4F formation in muscle
Am J Physiol Endocrinol Metab, December 1, 2007; 293(6): E1615 - E1621.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
A. Suryawan, R. A. Orellana, H. V. Nguyen, A. S. Jeyapalan, J. R. Fleming, and T. A. Davis
Activation by insulin and amino acids of signaling components leading to translation initiation in skeletal muscle of neonatal pigs is developmentally regulated
Am J Physiol Endocrinol Metab, December 1, 2007; 293(6): E1597 - E1605.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
A. S. Jeyapalan, R. A. Orellana, A. Suryawan, P. M. J. O'Connor, H. V. Nguyen, J. Escobar, J. W. Frank, and T. A. Davis
Glucose stimulates protein synthesis in skeletal muscle of neonatal pigs through an AMPK- and mTOR-independent process
Am J Physiol Endocrinol Metab, August 1, 2007; 293(2): E595 - E603.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
R. A. Frost and C. H. Lang
Protein kinase B/Akt: a nexus of growth factor and cytokine signaling in determining muscle mass
J Appl Physiol, July 1, 2007; 103(1): 378 - 387.
[Abstract] [Full Text] [PDF]

Home page
 J. Nutr.Home page
X. Wang, S. Qiao, Y. Yin, L. Yue, Z. Wang, and G. Wu
A Deficiency or Excess of Dietary Threonine Reduces Protein Synthesis in Jejunum and Skeletal Muscle of Young Pigs
J. Nutr., June 1, 2007; 137(6): 1442 - 1446.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 2006 by the American Physiological Society.