The branched chain amino acid (BCAA) leucine is able to signal transduction pathways that modulate translation initiation for protein synthesis in skeleton muscles. In the presence of leucine, hyperphosphorylation of 4E-BP1 causes its affinity for eIF4E to be lowered. This allows eIF4F protein complexes to recognize, unfold and guide the mRNA to the 43S preinitiation complex thereby increasing translation initiation. In addition, leucine has a transient affect on the release of insulin and/or enhances sensitivity of muscle cells to insulin. A culmination of both signals at the mammalian target of rapamycin (mTOR) and perhaps other signaling, such as PKCδ, are needed for maximum translation initiation to occur.

Leucine Stimulation on Insulin Signaling References