Poxvirus decapping enzymes enhance virulence by preventing the accumulation of dsRNA and the induction of innate antiviral responses.
Cell Host Microbe
; 17(3): 320-331, 2015 Mar 11.
Article
em En
| MEDLINE
| ID: mdl-25766293
ABSTRACT
Poxvirus replication involves synthesis of double-stranded RNA (dsRNA), which can trigger antiviral responses by inducing phosphorylation-mediated activation of protein kinase R (PKR) and stimulating 2'5'-oligoadenylate synthetase (OAS). PKR inactivates the translation initiation factor eIF2α via phosphorylation, while OAS induces the endonuclease RNase L to degrade RNA. We show that poxvirus decapping enzymes D9 and D10, which remove caps from mRNAs, inhibit these antiviral responses by preventing dsRNA accumulation. Catalytic site mutations of D9 and D10, but not of either enzyme alone, halt vaccinia virus late protein synthesis and inhibit virus replication. Infection with the D9-D10 mutant was accompanied by massive mRNA reduction, cleavage of ribosomal RNA, and phosphorylation of PKR and eIF2α that correlated with a â¼ 15-fold increase in dsRNA compared to wild-type virus. Additionally, mouse studies show extreme attenuation of the mutant virus. Thus, vaccinia virus decapping, in addition to targeting mRNAs for degradation, prevents dsRNA accumulation and anti-viral responses.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Vaccinia virus
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Replicação Viral
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RNA de Cadeia Dupla
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Endorribonucleases
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Imunidade Inata
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article