mTOR: from growth signal integration to cancer, diabetes and ageing

In eukaryotes, the target of rapamycin (TOR) protein kinase simultaneously senses energy, nutrients and stress (and growth factors in metazoans) to regulate cell growth and division. Advances in our understanding of the regulation and functions of mammalian TOR (mTOR) are revealing its involvement in diabetes, cancer and ageing. In all eukaryotes, the target of rapamycin (TOR) signalling pathway couples energy and nutrient abundance to the execution of cell growth and division, owing to the ability of TOR protein kinase to simultaneously sense energy, nutrients and stress and, in metazoans, growth factors. Mammalian TOR complex 1 (mTORC1) and mTORC2 exert their actions by regulating other important kinases, such as S6 kinase (S6K) and Akt. In the past few years, a significant advance in our understanding of the regulation and functions of mTOR has revealed the crucial involvement of this signalling pathway in the onset and progression of diabetes, cancer and ageing.