The mammalian target of rapamycin (mTOR) is a Ser/Thr kinase structurally and functionally conserved from yeast to humans that positively regulates cell growth, proliferation, and survival, while inhibition of mTOR signaling extends lifespan (Harrison et al. 2009). In eukaryotes, mTOR is ubiquitously expressed and whole-organism knockout has demonstrated that it is essential for cell growth and viability. mTOR forms two multiprotein complexes, namely, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The macrolide rapamycin acutely inhibits mTORC1 but not mTORC2. mTORC1 and mTORC2 regulate functionally distinct, yet partially overlapping, signaling networks that collectively control the spatial and temporal regulation of cell growth.
Nutrients and growth factors activate mTORC1, whereas low cellular energy levels or stress...
I offer my regrets to our colleagues whose excellent work I could not described due to space limitations. I acknowledge the Werner-Siemens Foundation for funding support and M.N. Hall for advice and the general figure template.
- Robitaille AM, Hall MN. mTOR. UCSD-Nature Molecule Pages. 2008. http://www.signaling-gateway.org/molecule/query?afcsid=A000094. Accessed 15 Oct 2008.