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Skeletal muscle protein synthesis and the abundance of the mRNA translation initiation repressor PDCD4 are inversely regulated by fasting and refeeding in rats.

Publication ,  Journal Article
Zargar, S; Moreira, TS; Samimi-Seisan, H; Jeganathan, S; Kakade, D; Islam, N; Campbell, J; Adegoke, OAJ
Published in: Am J Physiol Endocrinol Metab
June 2011

Optimal skeletal muscle mass is vital to human health, because defects in muscle protein metabolism underlie or exacerbate human diseases. The mammalian target of rapamycin complex 1 is critical in the regulation of mRNA translation and protein synthesis. These functions are mediated in part by the ribosomal protein S6 kinase 1 (S6K1) through mechanisms that are poorly understood. The tumor suppressor programmed cell death 4 (PDCD4) has been identified as a novel substrate of S6K1. Here, we examined 1) the expression of PDCD4 in skeletal muscle and 2) its regulation by feed deprivation (FD) and refeeding. Male rats (~100 g; n = 6) were subjected to FD for 48 h; some rats were refed for 2 h. FD suppressed muscle fractional rates of protein synthesis and Ser(67) phosphorylation of PDCD4 (-50%) but increased PDCD4 abundance (P < 0.05); refeeding reversed these changes (P < 0.05). Consistent with these effects being regulated by S6K1, activation of this kinase was suppressed by FD (-91%, P < 0.05) but was increased by refeeding. Gavaging rats subjected to FD with a mixture of amino acids partially restored muscle fractional rates of protein synthesis and reduced PDCD4 abundance relative to FD. Finally, when myoblasts were grown in amino acid- and serum-free medium, phenylalanine incorporation into proteins in cells depleted of PDCD4 more than doubled the values in cells with a normal level of PDCD4 (P < 0.0001). Thus feeding stimulates fractional protein synthesis in skeletal muscle in parallel with the reduction of the abundance of this mRNA translation inhibitor.

Duke Scholars

Published In

Am J Physiol Endocrinol Metab

DOI

EISSN

1522-1555

Publication Date

June 2011

Volume

300

Issue

6

Start / End Page

E986 / E992

Location

United States

Related Subject Headings

  • Transcription Factors
  • Rats, Sprague-Dawley
  • Rats
  • RNA, Messenger
  • RNA Interference
  • Phenylalanine
  • Myoblasts
  • Muscle, Skeletal
  • Muscle Proteins
  • Muscle Fibers, Skeletal
 

Citation

APA
Chicago
ICMJE
MLA
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Zargar, S., Moreira, T. S., Samimi-Seisan, H., Jeganathan, S., Kakade, D., Islam, N., … Adegoke, O. A. J. (2011). Skeletal muscle protein synthesis and the abundance of the mRNA translation initiation repressor PDCD4 are inversely regulated by fasting and refeeding in rats. Am J Physiol Endocrinol Metab, 300(6), E986–E992. https://doi.org/10.1152/ajpendo.00642.2010
Zargar, Sana, Tracy S. Moreira, Helena Samimi-Seisan, Senthure Jeganathan, Dhanshri Kakade, Nushaba Islam, Jonathan Campbell, and Olasunkanmi A. J. Adegoke. “Skeletal muscle protein synthesis and the abundance of the mRNA translation initiation repressor PDCD4 are inversely regulated by fasting and refeeding in rats.Am J Physiol Endocrinol Metab 300, no. 6 (June 2011): E986–92. https://doi.org/10.1152/ajpendo.00642.2010.
Zargar S, Moreira TS, Samimi-Seisan H, Jeganathan S, Kakade D, Islam N, et al. Skeletal muscle protein synthesis and the abundance of the mRNA translation initiation repressor PDCD4 are inversely regulated by fasting and refeeding in rats. Am J Physiol Endocrinol Metab. 2011 Jun;300(6):E986–92.
Zargar, Sana, et al. “Skeletal muscle protein synthesis and the abundance of the mRNA translation initiation repressor PDCD4 are inversely regulated by fasting and refeeding in rats.Am J Physiol Endocrinol Metab, vol. 300, no. 6, June 2011, pp. E986–92. Pubmed, doi:10.1152/ajpendo.00642.2010.
Zargar S, Moreira TS, Samimi-Seisan H, Jeganathan S, Kakade D, Islam N, Campbell J, Adegoke OAJ. Skeletal muscle protein synthesis and the abundance of the mRNA translation initiation repressor PDCD4 are inversely regulated by fasting and refeeding in rats. Am J Physiol Endocrinol Metab. 2011 Jun;300(6):E986–E992.

Published In

Am J Physiol Endocrinol Metab

DOI

EISSN

1522-1555

Publication Date

June 2011

Volume

300

Issue

6

Start / End Page

E986 / E992

Location

United States

Related Subject Headings

  • Transcription Factors
  • Rats, Sprague-Dawley
  • Rats
  • RNA, Messenger
  • RNA Interference
  • Phenylalanine
  • Myoblasts
  • Muscle, Skeletal
  • Muscle Proteins
  • Muscle Fibers, Skeletal