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

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...

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Autores principales: Abou Sawan, Sidney, van Vliet, Stephan, Parel, Justin T., Beals, Joseph W., Mazzulla, Michael, West, Daniel W. D., Philp, Andrew, Li, Zhong, Paluska, Scott A., Burd, Nicholas A., Moore, Daniel R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5840389/
https://www.ncbi.nlm.nih.gov/pubmed/29512299
http://dx.doi.org/10.14814/phy2.13628
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author Abou Sawan, Sidney
van Vliet, Stephan
Parel, Justin T.
Beals, Joseph W.
Mazzulla, Michael
West, Daniel W. D.
Philp, Andrew
Li, Zhong
Paluska, Scott A.
Burd, Nicholas A.
Moore, Daniel R.
author_facet Abou Sawan, Sidney
van Vliet, Stephan
Parel, Justin T.
Beals, Joseph W.
Mazzulla, Michael
West, Daniel W. D.
Philp, Andrew
Li, Zhong
Paluska, Scott A.
Burd, Nicholas A.
Moore, Daniel R.
author_sort Abou Sawan, Sidney
collection PubMed
description 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‐(2)H(5)]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% VO(2peak) (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‐BP1(Thr37/46) and rpS6(ser240/244) 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.
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spelling pubmed-58403892018-03-13 Translocation and protein complex co‐localization of mTOR is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise Abou Sawan, Sidney van Vliet, Stephan Parel, Justin T. Beals, Joseph W. Mazzulla, Michael West, Daniel W. D. Philp, Andrew Li, Zhong Paluska, Scott A. Burd, Nicholas A. Moore, Daniel R. Physiol Rep Original Research 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‐(2)H(5)]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% VO(2peak) (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‐BP1(Thr37/46) and rpS6(ser240/244) 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. John Wiley and Sons Inc. 2018-03-07 /pmc/articles/PMC5840389/ /pubmed/29512299 http://dx.doi.org/10.14814/phy2.13628 Text en © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Research
Abou Sawan, Sidney
van Vliet, Stephan
Parel, Justin T.
Beals, Joseph W.
Mazzulla, Michael
West, Daniel W. D.
Philp, Andrew
Li, Zhong
Paluska, Scott A.
Burd, Nicholas A.
Moore, Daniel R.
Translocation and protein complex co‐localization of mTOR is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise
title Translocation and protein complex co‐localization of mTOR is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise
title_full Translocation and protein complex co‐localization of mTOR is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise
title_fullStr Translocation and protein complex co‐localization of mTOR is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise
title_full_unstemmed Translocation and protein complex co‐localization of mTOR is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise
title_short Translocation and protein complex co‐localization of mTOR is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise
title_sort translocation and protein complex co‐localization of mtor is associated with postprandial myofibrillar protein synthesis at rest and after endurance exercise
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5840389/
https://www.ncbi.nlm.nih.gov/pubmed/29512299
http://dx.doi.org/10.14814/phy2.13628
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