Principles of cotranslational ubiquitination and quality control at the ribosome.
Mol Cell
; 50(3): 379-93, 2013 May 09.
Article
en En
| MEDLINE
| ID: mdl-23583075
Achieving efficient cotranslational folding of complex proteomes poses a challenge for eukaryotic cells. Nascent polypeptides that emerge vectorially from the ribosome often cannot fold stably and may be susceptible to misfolding and degradation. The extent to which nascent chains are subject to cotranslational quality control and degradation remains unclear. Here, we directly and quantitatively assess cotranslational ubiquitination and identify, at a systems level, the determinants and factors governing this process. Cotranslational ubiquitination occurs at very low levels and is carried out by a complex network of E3 ubiquitin ligases. Ribosome-associated chaperones and cotranslational folding protect the majority of nascent chains from premature quality control. Nonetheless, a number of nascent chains whose intrinsic properties hinder efficient cotranslational folding remain susceptible for cotranslational ubiquitination. We find that quality control at the ribosome is achieved through a tiered system wherein nascent polypeptides have a chance to fold before becoming accessible to ubiquitination.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ribosomas
/
Biosíntesis de Proteínas
/
Ubiquitinación
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Mol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2013
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos