Cargando…

Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand

Skeletal muscle protein synthesis is a highly complex process, influenced by nutritional status, mechanical stimuli, repair programs, hormones, and growth factors. The molecular aspects of protein synthesis are centered around the mTORC1 complex. However, the intricacies of mTORC1 regulation, both u...

Descripción completa

Detalles Bibliográficos
Autor principal: White, James P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8201612/
https://www.ncbi.nlm.nih.gov/pubmed/34136478
http://dx.doi.org/10.3389/fcell.2021.656604
_version_ 1783707840215515136
author White, James P.
author_facet White, James P.
author_sort White, James P.
collection PubMed
description Skeletal muscle protein synthesis is a highly complex process, influenced by nutritional status, mechanical stimuli, repair programs, hormones, and growth factors. The molecular aspects of protein synthesis are centered around the mTORC1 complex. However, the intricacies of mTORC1 regulation, both up and downstream, have expanded overtime. Moreover, the plastic nature of skeletal muscle makes it a unique tissue, having to coordinate between temporal changes in myofiber metabolism and hypertrophy/atrophy stimuli within a tissue with considerable protein content. Skeletal muscle manages the push and pull between anabolic and catabolic pathways through key regulatory proteins to promote energy production in times of nutrient deprivation or activate anabolic pathways in times of nutrient availability and anabolic stimuli. Branched-chain amino acids (BCAAs) can be used for both energy production and signaling to induce protein synthesis. The metabolism of BCAAs occur in tandem with energetic and anabolic processes, converging at several points along their respective pathways. The fate of intramuscular BCAAs adds another layer of regulation, which has consequences to promote or inhibit muscle fiber protein anabolism. This review will outline the general mechanisms of muscle protein synthesis and describe how metabolic pathways can regulate this process. Lastly, we will discuss how BCAA availability and demand coordinate with synthesis mechanisms and identify key factors involved in intramuscular BCAA trafficking.
format Online
Article
Text
id pubmed-8201612
institution National Center for Biotechnology Information
language English
publishDate 2021
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-82016122021-06-15 Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand White, James P. Front Cell Dev Biol Cell and Developmental Biology Skeletal muscle protein synthesis is a highly complex process, influenced by nutritional status, mechanical stimuli, repair programs, hormones, and growth factors. The molecular aspects of protein synthesis are centered around the mTORC1 complex. However, the intricacies of mTORC1 regulation, both up and downstream, have expanded overtime. Moreover, the plastic nature of skeletal muscle makes it a unique tissue, having to coordinate between temporal changes in myofiber metabolism and hypertrophy/atrophy stimuli within a tissue with considerable protein content. Skeletal muscle manages the push and pull between anabolic and catabolic pathways through key regulatory proteins to promote energy production in times of nutrient deprivation or activate anabolic pathways in times of nutrient availability and anabolic stimuli. Branched-chain amino acids (BCAAs) can be used for both energy production and signaling to induce protein synthesis. The metabolism of BCAAs occur in tandem with energetic and anabolic processes, converging at several points along their respective pathways. The fate of intramuscular BCAAs adds another layer of regulation, which has consequences to promote or inhibit muscle fiber protein anabolism. This review will outline the general mechanisms of muscle protein synthesis and describe how metabolic pathways can regulate this process. Lastly, we will discuss how BCAA availability and demand coordinate with synthesis mechanisms and identify key factors involved in intramuscular BCAA trafficking. Frontiers Media S.A. 2021-05-31 /pmc/articles/PMC8201612/ /pubmed/34136478 http://dx.doi.org/10.3389/fcell.2021.656604 Text en Copyright © 2021 White. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Cell and Developmental Biology
White, James P.
Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand
title Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand
title_full Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand
title_fullStr Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand
title_full_unstemmed Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand
title_short Amino Acid Trafficking and Skeletal Muscle Protein Synthesis: A Case of Supply and Demand
title_sort amino acid trafficking and skeletal muscle protein synthesis: a case of supply and demand
topic Cell and Developmental Biology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8201612/
https://www.ncbi.nlm.nih.gov/pubmed/34136478
http://dx.doi.org/10.3389/fcell.2021.656604
work_keys_str_mv AT whitejamesp aminoacidtraffickingandskeletalmuscleproteinsynthesisacaseofsupplyanddemand