In young, healthy men who exercise recreationally, consuming leucine is linked to specific molecular changes in muscle cells that are thought to support increased muscle protein synthesis.
Mechanism
Synthesis from 1 study
Eating leucine causes a signal to travel into muscle cells, moving a key protein to the right location to turn on protein production. This turns up the activity of the cell’s protein-making machinery, leading to more muscle protein being built.
Most probable mechanism
When leucine is consumed, it enters muscle cells and triggers a chain reaction that moves a key protein complex to the surface of cellular recycling centers. There, it gets turned on and flips a switch on another protein that tells the cell’s protein-making machines to work faster, leading to more muscle protein being built.
Leucine is absorbed from the bloodstream into skeletal muscle cells.
Intracellular leucine binds to specific sensors that release inhibition on a regulatory complex controlling mTORC1 localization.
The mTORC1 complex is recruited to the surface of lysosomes through activation of Rag GTPases.
mTORC1 translocates to the peripheral region of the muscle cell membrane, where it encounters activating signals and substrates.
Activated mTORC1 phosphorylates the ribosomal protein RPS6 at specific sites on its surface.
Phosphorylated RPS6 increases the efficiency of ribosomes in initiating protein synthesis, leading to higher rates of myofibrillar protein production.
Evidence from Studies
Supporting (1)
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Leucine ingestion promotes mTOR translocation to the periphery and enhances total and peripheral RPS6 phosphorylation in human skeletal muscle
Contradicting (0)
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