Rictor/TORC2 regulates Caenorhabditis elegans fat storage, body size, and development through sgk-1.
PLoS Biol
; 7(3): e60, 2009 Mar 03.
Article
em En
| MEDLINE
| ID: mdl-19260765
ABSTRACT
The target of rapamycin (TOR) kinase coordinately regulates fundamental metabolic and cellular processes to support growth, proliferation, survival, and differentiation, and consequently it has been proposed as a therapeutic target for the treatment of cancer, metabolic disease, and aging. The TOR kinase is found in two biochemically and functionally distinct complexes, termed TORC1 and TORC2. Aided by the compound rapamycin, which specifically inhibits TORC1, the role of TORC1 in regulating translation and cellular growth has been extensively studied. The physiological roles of TORC2 have remained largely elusive due to the lack of pharmacological inhibitors and its genetic lethality in mammals. Among potential targets of TORC2, the pro-survival kinase AKT has garnered much attention. Within the context of intact animals, however, the physiological consequences of phosphorylation of AKT by TORC2 remain poorly understood. Here we describe viable loss-of-function mutants in the Caenorhabditis elegans homolog of the TORC2-specific component, Rictor (CeRictor). These mutants display a mild developmental delay and decreased body size, but have increased lipid storage. These functions of CeRictor are not mediated through the regulation of AKT kinases or their major downstream target, the insulin-regulated FOXO transcription factor DAF-16. We found that loss of sgk-1, a homolog of the serum- and glucocorticoid-induced kinase, mimics the developmental, growth, and metabolic phenotypes of CeRictor mutants, while a novel, gain-of-function mutation in sgk-1 suppresses these phenotypes, indicating that SGK-1 is a mediator of CeRictor activity. These findings identify new physiological roles for TORC2, mediated by SGK, in regulation of C. elegans lipid accumulation and growth, and they challenge the notion that AKT is the primary effector of TORC2 function.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Transporte
/
Proteínas Serina-Treonina Quinases
/
Caenorhabditis elegans
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Regulação da Expressão Gênica no Desenvolvimento
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Proteínas de Caenorhabditis elegans
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Proteínas Proto-Oncogênicas c-akt
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
PLoS Biol
Assunto da revista:
BIOLOGIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos