A novel ubiquitination factor, E4, is involved in multiubiquitin chain assembly.
Cell
; 96(5): 635-44, 1999 Mar 05.
Article
en En
| MEDLINE
| ID: mdl-10089879
ABSTRACT
Proteins modified by multiubiquitin chains are the preferred substrates of the proteasome. Ubiquitination involves a ubiquitin-activating enzyme, E1, a ubiquitin-conjugating enzyme, E2, and often a substrate-specific ubiquitin-protein ligase, E3. Here we show that efficient multiubiquitination needed for proteasomal targeting of a model substrate requires an additional conjugation factor, named E4. This protein, previously known as UFD2 in yeast, binds to the ubiquitin moieties of preformed conjugates and catalyzes ubiquitin chain assembly in conjunction with E1, E2, and E3. Intriguingly, E4 defines a novel protein family that includes two human members and the regulatory protein NOSA from Dictyostelium required for fruiting body development. In yeast, E4 activity is linked to cell survival under stress conditions, indicating that eukaryotes utilize E4-dependent proteolysis pathways for multiple cellular functions.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Saccharomyces cerevisiae
/
Proteínas Fúngicas
/
Ubiquitinas
/
Proteínas de Saccharomyces cerevisiae
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Cell
Año:
1999
Tipo del documento:
Article
País de afiliación:
Alemania