After consuming 25 grams of whey protein, young adults experience a reduction in a specific muscle protein called IP6K1, which coincides with increased processing of the amino acid phenylalanine and...
Mechanism
Synthesis from 1 study
After drinking a whey protein shake, a brake on muscle growth gets turned off, letting more building blocks enter the muscle cells. This activates a molecular switch that tells the cell to start making more proteins, helping muscles repair and grow.
Most probable mechanism
When whey protein is consumed, the body reduces a specific enzyme in muscle cells that normally blocks a key growth signal. This allows more amino acids to enter the cell, which activates a molecular switch that turns on protein building. As a result, the cell starts making more muscle proteins.
Ingestion of whey protein triggers a decline in IP6K1 enzyme levels in skeletal muscle within 240 minutes.
Lower IP6K1 reduces production of IP7, which normally binds to Akt and prevents its activation at the cell membrane.
Reduced IP7 binding allows Akt to translocate to the plasma membrane and become phosphorylated at Thr308.
Activated Akt stimulates mTORC1, leading to increased phosphorylation of 4E-BP1 and release of eIF4E to initiate mRNA translation.
Downregulation of IP6K1 coincides with increased expression of LAT1, enhancing transport of leucine and other amino acids into muscle cells to sustain mTORC1 activation.
Increased amino acid availability and mTORC1 signaling elevate phenylalanine disposal, indicating enhanced protein synthesis capacity.
Evidence from Studies
Supporting (1)
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Inositol hexakisphosphate kinase 1 is implicated in the insulin response to protein ingestion in older adults
Contradicting (0)
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