Activated by nutrient and growth factors

Signaling pathways activated by nutrient and growth factors. 
e.g. mTORC1 where activation is one of the several examples of a key sensing signaling process where, in spite of intense interest, actual nutrient sensors remain unidentified. mTORC1 is not equally sensitive to all AAs, leucine being particularly important for its activation. [ Efy. 15 ]
See more generally: Cell signaling