Regulation of leucyl-trna synthetase and RagB expression in human skeletal muscle by essential amino acids

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Title Regulation of leucyl-trna synthetase and RagB expression in human skeletal muscle by essential amino acids
Publication Type thesis
School or College College of Health
Department Nutrition & Integrative Physiology
Author Carlin, Matthew Brian
Date 2014-08
Description Essential amino acids (EAA) are a potent stimulator of mammalian target of rapamycin complex 1 (mTORC1) signaling and muscle protein synthesis. However, the molecular regulators upstream of mTORC1 signaling that are stimulated by EAA are not well described in human skeletal muscle. Leucyl tRNA synthetase (LRS) and RagB have recently been shown to be important in mTORC1 activation, but their role in human skeletal muscle following EAA ingestion is unknown. The purpose of this study was to determine changes in protein expression and the association of the LRS- and RagB RagBmTORC1 complexes following acute EAA ingestion in healthy human skeletal muscle. Muscle biopsies (vastus lateralis) were obtained from 13 young adults (7M, 6F, 22.9 ± 0.9y, 21.7 ± 0.9 BMI) in the fasted state (basal) and 1 and 3 h after EAA (13g; 2.4g Leu) ingestion. Co-immunoprecipitation and western blotting were used to determine LRSand RagB-mTORC1 protein complexes and LRS and RagB protein expression, respectively. We report that EAA ingestion did not alter LRS- or RagB-mTORC1 association or LRS protein expression (P > 0.05) contrary to the robust increase in mTOR phosphorylation (P < 0.05). However, we found that EAA increased RagB protein abundance following EAA ingestion (P < 0.05). We conclude that LRS- and RagBmTORC1 complexes are not altered 1 and 3 h following EAA ingestion in healthy young adult skeletal muscle. However, the transient increase in RagB protein expression afterEAA ingestion may be an important mechanism to promote protein anabolism.
Type Text
Publisher University of Utah
Subject Essential amino acids; Leucyl trna synthetase; Mtor; Ragb
Dissertation Institution University of Utah
Dissertation Name Master of Science
Language eng
Rights Management Copyright © Matthew Brian Carlin 2014
Format application/pdf
Format Medium application/pdf
Format Extent 171,388 bytes
Identifier etd3/id/3137
ARK ark:/87278/s6h1697n
Setname ir_etd
ID 196704
Reference URL https://collections.lib.utah.edu/ark:/87278/s6h1697n
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