Glucose addiction of TSC null cells is caused by failed mTORC1-dependent balancing of metabolic demand with supply.
Mol Cell
; 38(4): 487-99, 2010 May 28.
Article
em En
| MEDLINE
| ID: mdl-20513425
ABSTRACT
The mTORC1-signaling pathway integrates environmental conditions into distinct signals for cell growth by balancing anabolic and catabolic processes. Accordingly, energetic stress inhibits mTORC1 signaling predominantly through AMPK-dependent activation of TSC1/2. Thus, TSC1/2-/- cells are hypersensitive to glucose deprivation, and this has been linked to increased p53 translation and activation of apoptosis. Herein, we show that mTORC1 inhibition during glucose deprivation prevented not only the execution of death, but also induction of energetic stress. mTORC1 inhibition during glucose deprivation decreased AMPK activation and allowed ATP to remain high, which was both necessary and sufficient for protection. This effect was not due to increased catabolic activities such as autophagy, but rather exclusively due to decreased anabolic processes, reducing energy consumption. Specifically, TSC1/2-/- cells become highly dependent on glutamate dehydrogenase-dependent glutamine metabolism via the TCA cycle for survival. Therefore, mTORC1 inhibition during energetic stress is primarily to balance metabolic demand with supply.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
/
Proteínas Supressoras de Tumor
/
Glucose
Limite:
Animals
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos