betaTrCP- and Rsk1/2-mediated degradation of BimEL inhibits apoptosis.
Mol Cell
; 33(1): 109-16, 2009 Jan 16.
Article
em En
| MEDLINE
| ID: mdl-19150432
ABSTRACT
The BimEL tumor suppressor is a potent proapoptotic BH3-only protein. We found that, in response to survival signals, BimEL was rapidly phosphorylated on three serine residues in a conserved degron, facilitating binding and degradation via the F box protein betaTrCP. Phosphorylation of the BimEL degron was executed by Rsk1/2 and promoted by the Erk1/2-mediated phosphorylation of BimEL on Ser69. Compared to wild-type BimEL, a BimEL phosphorylation mutant unable to bind betaTrCP was stabilized and consequently potent at inducing apoptosis by the intrinsic mitochondrial pathway. Moreover, although non-small cell lung cancer (NSCLC) cells often become resistant to gefitinib (a clinically relevant tyrosine kinase inhibitor that induces apoptosis through BimEL), silencing of either betaTrCP or Rsk1/2 resulted in BimEL-mediated apoptosis of both gefitinib-sensitive and gefitinib-insensitive NSCLC cells. Our findings reveal that betaTrCP promotes cell survival in cooperation with the ERK-RSK pathway by targeting BimEL for degradation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Processamento de Proteína Pós-Traducional
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Proteínas Proto-Oncogênicas
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Apoptose
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Proteínas Quinases S6 Ribossômicas 90-kDa
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Proteínas Contendo Repetições de beta-Transducina
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Proteínas Reguladoras de Apoptose
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Proteínas de Membrana
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos