Open AccessPKR-Dependent and -Independent Mechanisms Are Involved in Translational Shutoff during Sindbis Virus Infection
Author(s) -
Rodion Gorchakov,
Elena I. Frolova,
Bryan R.G. Williams,
Charles M. Rice,
Ilya Frolov
Publication year - 2004
Publication title -
journal of virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.617
H-Index - 292
eISSN - 1070-6321
pISSN - 0022-538X
DOI - 10.1128/jvi.78.16.8455-8467.2004
Subject(s) - protein kinase r , biology , sindbis virus , replicon , eif 2 kinase , virology , alphavirus , viral replication , interferon , translation (biology) , rna , microbiology and biotechnology , virus , subgenomic mrna , protein kinase a , kinase , messenger rna , genetics , gene , plasmid , mitogen activated protein kinase kinase , cyclin dependent kinase 2
The replication of Sindbis virus (SIN) profoundly affects the metabolism of infected vertebrate cells. One of the main events during SIN infection is the strong inhibition of translation of cellular mRNAs. In this study, we used a combination of approaches, including the study of SIN replication in PKR(-/-) mouse embryo fibroblasts or in the presence of an excess of catalytically inactive PKR. We show that the PKR-dependent inhibition of translation is not the only and most likely not the major pathway mediating translational shutoff during SIN infection. The PKR-independent mechanism strongly affects the translation of cellular templates, whereas translation of SIN subgenomic RNA is resistant to inhibition, and this leads to a benefit for viral replication. Our findings suggest that both PKR-dependent and non-PKR-dependent mechanisms of SIN-induced translational shutoff can be manipulated by using SIN replicons expressing mutated SIN nsP2 or kinase-defective PKR. Specifically, we show that expression of heterologous genes from SIN-based and most likely other alphavirus-based replicons can be increased by downregulating both the PKR-dependent and PKR-independent translational shutoffs.