MTOR signalling

Mammalian target of rapamycin (mTOR) is a highly conserved serine/threonine kinase that regulates cell growth and division in response to energy levels, growth signals, and nutrients. Control of mTOR activity is critical for the cell since its dysregulation leads to cancer, metabolic disease, and diabetes. In cells, mTOR exists as two structurally distinct complexes termed mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), each one with specificity for different sets of effectors (reviewed in Jhanwar-Uniyal et al. 2019). mTORC1 couples energy and nutrient abundance to cell growth and proliferation by balancing anabolic (protein synthesis and nutrient storage) and catabolic (autophagy and utilization of energy stores) processes. mTORC2 is responsive to growth factor signaling (reviewed in Jhanwar-Uniyal et al. 2019). mTORC1 and mTORC2 cross-talk through AKT and S6K (reviewed in Jhanwar-Uniyal et al. 2019). Rapamycin, the inhibitor of mTOR, inhibits only mTORC1, as the RICTOR subunit of mTORC2 masks the rapamycin-interacting domain of MTOR in mTORC2 (reviewed in Simcox and Lamming 2023).

Summary from Reactome (R-HSA-165159), read 2026-09-23.