Mechanistic target of rapamycin signaling cascade (mTOR signaling cascade)

The mechanistic target of rapamycin signaling cascade is a central intracellular signal transduction network that integrates inputs from nutrients, energy status, growth factors, stress signals—and regulates key cellular processes including protein synthesis, lipid metabolism, autophagy suppression/activation depending on context. The core component is mechanistic target of rapamycin (mTOR), a serine/threonine-protein kinase that functions within two distinct multiprotein complexes—mTOR Complex 1 (mTORC1) and Complex 2 (mTORC2). These complexes coordinate anabolic processes under favorable conditions while suppressing catabolic responses like autophagy during nutrient sufficiency. Dysregulation contributes significantly to cancer development/progression as well as other diseases involving abnormal cell proliferation or survival. Therapeutic strategies often focus on inhibiting one or more nodes within this network using small molecules like rapalogs or dual PI3K/mTor inhibitors.

Other names

mTOR pathwayMammalian/mechanistic target of rapamycin pathwayPI3K/AKT/mTOR pathway (when referring to the broader upstream/downstream context)TOR signaling pathway

Drugs targeting this pathway typically act by inhibiting kinase activity within the complex(es): Allosteric inhibition of mTOR kinase activity by binding FKBP12–rapamycin complex to FRB domain on mTOR. ATP‑competitive inhibition at the catalytic site for dual PI3K/mTOR inhibitors. Downregulation of downstream phosphorylation events required for cell growth/proliferation/survival.