Target of Rapamycin (TÜR) regulates growth in response to nutritional signals

A universal feature of all organisms is their ability to respond to nutrient availability by regulating growth and developmental programs. The identification of the target of rapamycin (TOR) pathway was a seminal discovery in the quest to understand the molecular mechanisms that govern such processes. TOR is an evolutionarily conserved serine/threonine kinase belonging to the family of phosphatidylinositol kinase-related kinases. Other members of this family include the mammalian DNA damage checkpoint kinases ATM and ATR,which are conserved from yeast to human, and DNA-PK and SMG1, which are not found in yeasts. TOR regulates growth (accumulation of mass), proliferation (accumulation in cell number), and survival in response to nutritional changes by diverse mechanisms that include regulation of anabolic and catabolic metabolism, nutrient uptake, protein translation and turnover, gene transcription, and the epigenome (reviewed in ^{1 - 3}).