Essential amino acid sensing, signaling, and transport in the regulation of human muscle protein metabolism

Jared M. Dickinson, Blake B. Rasmussen

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

Purpose of review: To highlight the recent research pertaining to the cellular mechanisms linking amino acid availability, mTORC1 signaling, and muscle protein metabolism. Recent findings: Activation of the mTORC1 pathway in response to amino acids may be dependent upon cellular relocalization of mTORC1, a process that appears to involve the Rag GTPases. Recent studies have also identified other intracellular proteins, such as hVps34 and MAP4K3, and specific amino acid transporters as necessary links between amino acid availability and mTORC1. In human skeletal muscle, it appears that mTORC1 activity increases the expression of several amino acid transporters, which may be an important adaptive response to sensitize muscle to a subsequent increase in amino acid availability. Summary: The precise cellular mechanisms linking amino acids to mTORC1 signaling and muscle protein metabolism are currently not well understood. More defined cellular mechanisms are beginning to emerge suggesting a role for several intracellular proteins including hVps34, MAP4K3, and Rag GTPases. Additionally, specific amino acid transporters may have a role both upstream and downstream of mTORC1. Continued investigation into the precise cellular mechanisms linking amino acid availability and muscle protein metabolism will help facilitate improvements in existing therapies for conditions of muscle wasting.

Original languageEnglish (US)
Pages (from-to)83-88
Number of pages6
JournalCurrent Opinion in Clinical Nutrition and Metabolic Care
Volume14
Issue number1
DOIs
StatePublished - Jan 1 2011

    Fingerprint

Keywords

  • Amino acid transporters
  • MTORC1
  • Protein synthesis

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

Cite this