TORC1 promotes phosphorylation of ribosomal protein S6 via the AGC kinase Ypk3 in Saccharomyces cerevisiae.
PLoS One
; 10(3): e0120250, 2015.
Article
em En
| MEDLINE
| ID: mdl-25767889
ABSTRACT
The target of rapamycin complex 1 (TORC1) is an evolutionarily conserved sensor of nutrient availability. Genetic and pharmacological studies in the yeast Saccharomyces cerevisiae have provided mechanistic insights on the regulation of TORC1 signaling in response to nutrients. Using a highly specific antibody that recognizes phosphorylation of the bona fide TORC1 target ribosomal protein S6 (Rps6) in yeast, we found that nutrients rapidly induce Rps6 phosphorylation in a TORC1-dependent manner. Moreover, we demonstrate that Ypk3, an AGC kinase which exhibits high homology to human S6 kinase (S6K), is required for the phosphorylation of Rps6 in vivo. Rps6 phosphorylation is completely abolished in cells lacking Ypk3 (ypk3Δ), whereas Sch9, previously reported to be the yeast ortholog of S6K, is dispensable for Rps6 phosphorylation. Phosphorylation-deficient mutations in regulatory motifs of Ypk3 abrogate Rps6 phosphorylation, and complementation of ypk3Δ cells with human S6 kinase restores Rps6 phosphorylation in a rapamycin-sensitive manner. Our findings demonstrate that Ypk3 is a critical component of the TORC1 pathway and that the use of a phospho-S6 specific antibody offers a valuable tool to identify new nutrient-dependent and rapamycin-sensitive targets in vivo.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Fatores de Transcrição
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Proteínas Serina-Treonina Quinases
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Proteínas Quinases Reguladas por Nucleotídeo Cíclico
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Proteínas Quinases S6 Ribossômicas
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Proteínas de Saccharomyces cerevisiae
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
PLoS One
Ano de publicação:
2015
Tipo de documento:
Article