mTOR
Serine/threonine kinase that integrates growth, nutrient, and stress signals to regulate cell growth and protein synthesis.
For laboratory and research use only — not for human consumption.
mTOR (mechanistic target of rapamycin, formerly mammalian target of rapamycin) is a 289 kDa serine/threonine protein kinase that integrates upstream nutrient, energy, and growth-factor signals to regulate cell growth, protein synthesis, autophagy, and metabolism. It operates in two distinct multiprotein complexes — mTORC1 (rapamycin-sensitive; principal regulator of translation via p70-S6K and 4E-BP1) and mTORC2 (rapamycin-insensitive at acute exposure; regulates Akt and cytoskeletal dynamics). Upstream activators include IGF-1, insulin, amino acids (particularly leucine), and growth-factor signalling through PI3K/Akt; inhibition by AMPK (energy-low state) and rapamycin sits at the centre of caloric-restriction and longevity research. mTOR is mechanistically relevant to multiple peptide research domains: IGF-1 LR3 and GH secretagogue research engages mTOR as the downstream growth signal; longevity peptides (epitalon, MOTS-c) are studied partly for their effects on mTOR/autophagy balance; muscle-protein-synthesis research uses mTOR phosphorylation (p-S6K1) as a primary endpoint. Chronic mTORC1 hyperactivation is one mechanism proposed to underlie accelerated cellular ageing.