Phosphoinositide 3-kinase and mechanistic target of rapamycin (PI3K and mTOR)

The **PI3K and mTOR** proteins are central nodes in a signal transduction network that coordinates inputs from growth factors, nutrients, and environmental cues to regulate essential cell functions, including growth, survival, proliferation, and metabolism. **PI3K** is a lipid kinase that generates phosphatidylinositol-3,4,5-trisphosphate (PIP3), which recruits Akt and other signaling molecules to propagate the pathway. **mTOR** is a serine/threonine protein kinase, existing in two main complexes (mTORC1, mTORC2), controlling protein synthesis, cell growth, and cytoskeletal organization. Aberrations in the PI3K/mTOR axis – through mutation, amplification, or deletion – are common drivers in human cancers and metabolic diseases. Pharmaceutical inhibitors targeting PI3K, mTOR, or both, have been developed for cancer and other indications, but therapeutic use is challenged by issues of specificity, resistance, and on-target toxicity[1][2][3][4][6][7][8]. **Note:** "PI3K and mTOR" is not a single molecule but rather two distinct proteins discussed together due to their close integration in signaling and therapeutic relevance. For clinical, research, or database purposes, the constituents should generally be described more specifically (e.g., "PIK3CA" for PI3K catalytic subunit alpha, "mechanistic target of rapamycin" for mTOR)[2][7].

Other names

PI3K-mTOR pathwayPI3K/Akt/mTOR pathwayPI3K-AKT-mTORPI3K/mTOR

Inhibition of kinase catalytic activity (of PI3K or mTOR) Blocking signal transduction downstream of growth factor receptors Disruption of cell growth, proliferation, and survival signaling Induction of apoptosis Modulation of metabolic activity