Stress-Induced Translation Inhibition through Rapid Displacement of Scanning Initiation Factors.
Mol Cell
; 80(3): 470-484.e8, 2020 11 05.
Article
em En
| MEDLINE
| ID: mdl-33053322
ABSTRACT
Cellular responses to environmental stress are frequently mediated by RNA-binding proteins (RBPs). Here, we examined global RBP dynamics in Saccharomyces cerevisiae in response to glucose starvation and heat shock. Each stress induced rapid remodeling of the RNA-protein interactome without corresponding changes in RBP abundance. Consistent with general translation shutdown, ribosomal proteins contacting the mRNA showed decreased RNA association. Among translation components, RNA association was most reduced for initiation factors involved in 40S scanning (eukaryotic initiation factor 4A [eIF4A], eIF4B, and Ded1), indicating a common mechanism of translational repression. In unstressed cells, eIF4A, eIF4B, and Ded1 primarily targeted the 5' ends of mRNAs. Following glucose withdrawal, 5' binding was abolished within 30 s, explaining the rapid translation shutdown, but mRNAs remained stable. Heat shock induced progressive loss of 5' RNA binding by initiation factors over â¼16 min and provoked mRNA degradation, particularly for translation-related factors, mediated by Xrn1. Taken together, these results reveal mechanisms underlying translational control of gene expression during stress.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estresse Fisiológico
/
Biossíntese de Proteínas
/
Fatores de Iniciação de Peptídeos
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article