mTOR

mTOR (mechanistic target of rapamycin) is a serine/threonine protein kinase that integrates nutrient, growth-factor, and energy signals to regulate cell growth, protein synthesis, and autophagy. The complex exists in two forms: mTORC1, which drives anabolism, and mTORC2, which has different downstream effects including cytoskeletal regulation.

Activated mTORC1 promotes ribosome biogenesis, protein translation, and lipogenesis. It is downstream of IGF-1, insulin, and amino-acid sensing — which is why high-protein meals and IGF-1 elevation both raise mTOR signaling. In the context of peptide research, GH-axis activation (via GHRH, GHRPs, or somatropin) increases IGF-1 and therefore mTOR tone.

Chronic mTOR activation is implicated in age-related decline, which is why longevity research often targets mTOR suppression — through caloric restriction, fasting, rapamycin, or pulsed protocols — to preserve autophagy and cellular cleanup.