Top

Research Article

Split Viewer

Mol. Cells 2010; 30(6): 513-518

Published online December 31, 2010

https://doi.org/10.1007/s10059-010-0147-3

© The Korean Society for Molecular and Cellular Biology

Mechanical Stretch Activates Signaling Events for Protein Translation Initiation and Elongation in C2C12 Myoblasts

Naoya Nakai1,*, Fuminori Kawano1, Yoshihiko Oke1, Sachiko Nomura1, Takashi Ohira2, Ryo Fujita1, and Yoshinobu Ohira1,2

1Section of Applied Physiology, Department of Health and Sports Sciences, Graduate School of Medicine, Osaka University, Osaka 560-0043, Japan, 2Section of Space Physiology, Graduate School of Frontier Biosciences, Osaka University, Osaka 560-0043, Japan

Correspondence to : *Correspondence: nakai@hss.osaka-u.ac.jp

Received: June 1, 2010; Revised: September 1, 2010; Accepted: September 2, 2010

Abstract

It has been proposed that mechanically induced tension is the critical factor in the induction of muscle hypertrophy. However, the molecular mechanisms involved in this process are still under investigation. In the present study, the effect of mechanical stretch on intracellular signaling for protein translation initiation and elongation was studied in C2C12 myoblasts. Cells were grown on a silicone elastomer chamber and subjected to 30-min of 5 or 15% constant static or cyclic (60 cycles/min) uniaxial stretch. Western blot analyses revealed that p70 S6 kinase (p70S6K) and eukaryotic elongation factor 2 (eEF2), which are the markers for translation initiation and peptide chain elongation, respectively, were activated by both static and cyclic stretch. The magnitude of activation was greater in response to the 15% cyclic stretch. Cyclic stretch also increased the phosphorylation of MAP kinases (p38 MAPK, ERK1/2 and JNK). However, the pharmacological inhibition of MAP kinases did not block the stretch-induced activation of p70S6K and eEF2. An inhibitor of the mammalian target of rapamycin (mTOR) blocked the stretch-induced phosphorylation of p70S6K but did not affect the eEF2 activation. A broad-range tyrosine kinase inhibitor, genistein, blocked the stretch-induced activation of p70S6K and eEF2, whereas Src tyrosine kinase and Janus kinase (JAK) inhibitors did not. These results suggest that the stretch-induced activation of protein translation initiation and elongation in mouse myoblast cell lines is mediated by tyrosine kinase(s), except for Src kinase or JAK.

Keywords C2C12 myoblasts, eukaryotic elongation factor 2, mechanical stretch, p70 S6 kinase, tyrosine phosphorylation

Article

Research Article

Mol. Cells 2010; 30(6): 513-518

Published online December 31, 2010 https://doi.org/10.1007/s10059-010-0147-3

Copyright © The Korean Society for Molecular and Cellular Biology.

Mechanical Stretch Activates Signaling Events for Protein Translation Initiation and Elongation in C2C12 Myoblasts

Naoya Nakai1,*, Fuminori Kawano1, Yoshihiko Oke1, Sachiko Nomura1, Takashi Ohira2, Ryo Fujita1, and Yoshinobu Ohira1,2

1Section of Applied Physiology, Department of Health and Sports Sciences, Graduate School of Medicine, Osaka University, Osaka 560-0043, Japan, 2Section of Space Physiology, Graduate School of Frontier Biosciences, Osaka University, Osaka 560-0043, Japan

Correspondence to:*Correspondence: nakai@hss.osaka-u.ac.jp

Received: June 1, 2010; Revised: September 1, 2010; Accepted: September 2, 2010

Abstract

It has been proposed that mechanically induced tension is the critical factor in the induction of muscle hypertrophy. However, the molecular mechanisms involved in this process are still under investigation. In the present study, the effect of mechanical stretch on intracellular signaling for protein translation initiation and elongation was studied in C2C12 myoblasts. Cells were grown on a silicone elastomer chamber and subjected to 30-min of 5 or 15% constant static or cyclic (60 cycles/min) uniaxial stretch. Western blot analyses revealed that p70 S6 kinase (p70S6K) and eukaryotic elongation factor 2 (eEF2), which are the markers for translation initiation and peptide chain elongation, respectively, were activated by both static and cyclic stretch. The magnitude of activation was greater in response to the 15% cyclic stretch. Cyclic stretch also increased the phosphorylation of MAP kinases (p38 MAPK, ERK1/2 and JNK). However, the pharmacological inhibition of MAP kinases did not block the stretch-induced activation of p70S6K and eEF2. An inhibitor of the mammalian target of rapamycin (mTOR) blocked the stretch-induced phosphorylation of p70S6K but did not affect the eEF2 activation. A broad-range tyrosine kinase inhibitor, genistein, blocked the stretch-induced activation of p70S6K and eEF2, whereas Src tyrosine kinase and Janus kinase (JAK) inhibitors did not. These results suggest that the stretch-induced activation of protein translation initiation and elongation in mouse myoblast cell lines is mediated by tyrosine kinase(s), except for Src kinase or JAK.

Keywords: C2C12 myoblasts, eukaryotic elongation factor 2, mechanical stretch, p70 S6 kinase, tyrosine phosphorylation

Mol. Cells
Sep 30, 2022 Vol.45 No.9, pp. 603~672
COVER PICTURE
The Target of Rapamycin Complex (TORC) is a central regulatory hub in eukaryotes, which is well conserved in diverse plant species, including tomato (Solanum lycopersicum). Inhibition of TORC genes (SlTOR, SlLST8, and SlRAPTOR) by VIGS (virus-induced gene silencing) results in early fruit ripening in tomato. The red/ orange tomatoes are early-ripened TORC-silenced fruits, while the green tomato is a control fruit. Top, left, control fruit (TRV2-myc); top, right, TRV2-SlLST8; bottom, left, TRV2-SlTOR; bottom, right, TRV2-SlRAPTOR(Choi et al., pp. 660-672).

Share this article on

  • line
  • mail

Molecules and Cells

eISSN 0219-1032
qr-code Download