Enhanced protein degradation by branched ubiquitin chains.
Cell
; 157(4): 910-21, 2014 May 08.
Article
em En
| MEDLINE
| ID: mdl-24813613
ABSTRACT
Posttranslational modification of cell-cycle regulators with ubiquitin chains is essential for eukaryotic cell division. Such chains can be connected through seven lysine residues or the amino terminus of ubiquitin, thereby allowing the assembly of eight homogenous and multiple mixed or branched conjugates. Although functions of homogenous chain types have been described, physiological roles of branched structures are unknown. Here, we report that the anaphase-promoting complex (APC/C) efficiently synthesizes branched conjugates that contain multiple blocks of K11-linked chains. Compared to homogenous chains, the branched conjugates assembled by the APC/C strongly enhance substrate recognition by the proteasome, thereby driving degradation of cell-cycle regulators during early mitosis. Our work, therefore, identifies an enzyme and substrates for modification with branched ubiquitin chains and points to an important role of these conjugates in providing an improved signal for proteasomal degradation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Complexo de Endopeptidases do Proteassoma
/
Proteólise
/
Ciclossomo-Complexo Promotor de Anáfase
Limite:
Humans
Idioma:
En
Revista:
Cell
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Estados Unidos