Resistance exercise initiates mechanistic target of rapamycin (mTOR) translocation and protein complex co-localisation in human skeletal muscle

Research output: Contribution to journalArticle

Authors

  • Zhe Song
  • Daniel R. Moore
  • Nathan Hodson
  • Mary F O'Leary
  • Andrew M Shaw
  • D. Lee Hamilton
  • Yann-Gaël Gangloff
  • Troy A. Hornberger
  • Lawrence L. Spriet
  • George J. Heigenhauser

External organisations

  • Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada.
  • School of Sport, University of Stirling, Scotland, UK.
  • Institut NeuroMyoGene (INMG), University Lyon 1, INSERM U 1217, Lyon, France.
  • Department of Comparative Biosciences, The University of Wisconsin, Madison, USA.
  • Faculty of Kinesiology and Physical Education, University of Toronto
  • Department of Medicine, Gastroenterology Division, McMaster University

Abstract

The mechanistic target of rapamycin (mTOR) is a central mediator of protein synthesis in skeletal muscle. We utilized immunofluorescence approaches to study mTOR cellular distribution and protein-protein co-localisation in human skeletal muscle in the basal state as well as immediately, 1 and 3 h after an acute bout of resistance exercise in a fed (FED; 20 g Protein/40 g carbohydrate/1 g fat) or energy-free control (CON) state. mTOR and the lysosomal protein LAMP2 were highly co-localised in basal samples. Resistance exercise resulted in rapid translocation of mTOR/LAMP2 towards the cell membrane. Concurrently, resistance exercise led to the dissociation of TSC2 from Rheb and increased in the co-localisation of mTOR and Rheb post exercise in both FED and CON. In addition, mTOR co-localised with Eukaryotic translation initiation factor 3 subunit F (eIF3F) at the cell membrane post-exercise in both groups, with the response significantly greater at 1 h of recovery in the FED compared to CON. Collectively our data demonstrate that cellular trafficking of mTOR occurs in human muscle in response to an anabolic stimulus, events that appear to be primarily influenced by muscle contraction. The translocation and association of mTOR with positive regulators (i.e. Rheb and eIF3F) is consistent with an enhanced mRNA translational capacity after resistance exercise.

Details

Original languageEnglish
Article number5028
JournalScientific Reports
Volume7
Issue number1
Publication statusPublished - 10 Jul 2017

Keywords

  • Journal Article, cell biology , TOR signalling