Poliovirus 2A proteinase cleaves directly the eIF-4G subunit of eIF-4F complex.
FEBS Lett
; 435(1): 79-83, 1998 Sep 11.
Article
en En
| MEDLINE
| ID: mdl-9755863
ABSTRACT
The initiation of translation on eukaryotic mRNA is governed by the concerted action of polypeptides of the eIF-4F complex. One of these polypeptides, eIF-4G, is proteolytically inactivated upon infection with several members of the Picornaviridae family. This cleavage occurs by the action of virus-encoded proteinases 2Apro (entero- and rhinovirus) or Lpro (aphthovirus). An indirect mode of eIF-4G cleavage through the activation of a second cellular proteinase has been proposed in the case of poliovirus. Although cleavage of eIF4G by rhino- and coxsackievirus 2Apro has been achieved directly in vitro, a similar activity has not been documented to date for poliovirus 2Apro. We report here that a recombinant form of poliovirus 2Apro fused to maltose binding protein (MBP) directly cleaves human eIF-4G from a highly purified eIF-4F complex. Efficient cleavage of eIF-4G requires magnesium ions. The presence of other initiation factors such as eIF-3, eIF-4A or eIF-4B mimics in part the stimulatory effect of magnesium ions and probably stabilizes the cleavage products of eIF-4G generated by 2Apro. These results suggest that efficient cleavage of eIF4G by MBP-2Apro requires a proper conformation of this factor. Finally, MBP-2Apro protein cleaves an eIF-4G-derived synthetic peptide at the same site as rhino- and coxsackievirus 2Apro (R485-G486).
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Virales
/
Cisteína Endopeptidasas
/
Factores de Iniciación de Péptidos
/
Poliovirus
Límite:
Humans
Idioma:
En
Revista:
FEBS Lett
Año:
1998
Tipo del documento:
Article
País de afiliación:
España