Cell Biology

Coordinating Energy Consumption

Science's STKE  06 Nov 2001:
Vol. 2001, Issue 107, pp. tw415
DOI: 10.1126/stke.2001.107.tw415

The mammalian target of the immunosuppressant (and anticancer agent) rapamycin (mTOR) controls ribosome biogenesis in response to nutrients and is now shown to be a sensor of the energy status of the cell. Given that protein synthesis consumes a lot of energy, Dennis et al. found that treatments that decreased the cellular concentration of adenosine triphosphate (ATP) also decreased mTOR activity. In fact, mTOR exhibits a Michaelis constant for ATP similar to the concentration of ATP in a mammalian cell. Thus, mTOR seems to function as a key node for regulation of ribosome biogenesis, replete with distinct mechanisms to coordinate ribosome function with availability of ATP or amino acids.

P. B. Dennis, A. Jaeschke, M. Saitoh, B. Fowler, S. C. Kozma, G. Thomas, Mammalian TOR: A homeostatic ATP sensor. Science 294, 1102-1105 (2001). [Abstract] [Full Text]