Translocation and protein complex co‐localization of mTOR is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise

Translocation and protein complex co‐localization of mTOR is associated with postprandial... Translocation and colocalization of mechanistic target of rapamycin complex 1 (mTORC1) with regulatory proteins represents a critical step in translation initiation of protein synthesis in vitro. However, mechanistic insight into the control of postprandial skeletal muscle protein synthesis rates at rest and after an acute bout of endurance exercise in humans is lacking. In crossover trials, eight endurance‐trained men received primed‐continuous infusions of L‐[ring‐2H5]phenylalanine and consumed a mixed‐macronutrient meal (18 g protein, 60 g carbohydrates, 17 g fat) at rest (REST) and after 60 min of treadmill running at 70% VO2peak (EX). Skeletal muscle biopsies were collected to measure changes in phosphorylation and colocalization in the mTORC1‐pathway, in addition to rates of myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis. MyoPS increased (P < 0.05) above fasted in REST (~2.1‐fold) and EX (~twofold) during the 300 min postprandial period, with no corresponding changes in MitoPS (P > 0.05). TSC2/Rheb colocalization decreased below fasted at 60 and 300 min after feeding in REST and EX (P < 0.01). mTOR colocalization with Rheb increased above fasted at 60 and 300 min after feeding in REST and EX (P < 0.01), which was consistent with an increased phosphorylation 4E‐BP1Thr37/46 and rpS6ser240/244 at 60 min. Our data suggest that MyoPS, but not MitoPS, is primarily nutrient responsive in trained young men at rest and after endurance exercise. The postprandial increase in MyoPS is associated with an increase in mTOR/Rheb colocalization and a reciprocal decrease in TSC2/Rheb colocalization and thus likely represent important regulatory events for in vivo skeletal muscle myofibrillar mRNA translation in humans. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Physiological Reports Wiley

Translocation and protein complex co‐localization of mTOR is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise

Loading next page...
 
/lp/wiley/translocation-and-protein-complex-co-localization-of-mtor-is-TXmJy2Iclw
Publisher
Wiley Subscription Services, Inc., A Wiley Company
Copyright
© 2018 Published by the American Physiological Society and The Physiological Society
ISSN
2051-817X
eISSN
2051-817X
D.O.I.
10.14814/phy2.13628
Publisher site
See Article on Publisher Site

Abstract

Translocation and colocalization of mechanistic target of rapamycin complex 1 (mTORC1) with regulatory proteins represents a critical step in translation initiation of protein synthesis in vitro. However, mechanistic insight into the control of postprandial skeletal muscle protein synthesis rates at rest and after an acute bout of endurance exercise in humans is lacking. In crossover trials, eight endurance‐trained men received primed‐continuous infusions of L‐[ring‐2H5]phenylalanine and consumed a mixed‐macronutrient meal (18 g protein, 60 g carbohydrates, 17 g fat) at rest (REST) and after 60 min of treadmill running at 70% VO2peak (EX). Skeletal muscle biopsies were collected to measure changes in phosphorylation and colocalization in the mTORC1‐pathway, in addition to rates of myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis. MyoPS increased (P < 0.05) above fasted in REST (~2.1‐fold) and EX (~twofold) during the 300 min postprandial period, with no corresponding changes in MitoPS (P > 0.05). TSC2/Rheb colocalization decreased below fasted at 60 and 300 min after feeding in REST and EX (P < 0.01). mTOR colocalization with Rheb increased above fasted at 60 and 300 min after feeding in REST and EX (P < 0.01), which was consistent with an increased phosphorylation 4E‐BP1Thr37/46 and rpS6ser240/244 at 60 min. Our data suggest that MyoPS, but not MitoPS, is primarily nutrient responsive in trained young men at rest and after endurance exercise. The postprandial increase in MyoPS is associated with an increase in mTOR/Rheb colocalization and a reciprocal decrease in TSC2/Rheb colocalization and thus likely represent important regulatory events for in vivo skeletal muscle myofibrillar mRNA translation in humans.

Journal

Physiological ReportsWiley

Published: Jan 1, 2018

Keywords: ; ; ; ;

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve Freelancer

DeepDyve Pro

Price
FREE
$49/month

$360/year
Save searches from
Google Scholar,
PubMed
Create lists to
organize your research
Export lists, citations
Read DeepDyve articles
Abstract access only
Unlimited access to over
18 million full-text articles
Print
20 pages/month
PDF Discount
20% off