Protein Expression Redirects Vesicular Stomatitis Virus RNA Synthesis to Cytoplasmic Inclusions

PLoS Pathogens

Bianca S. Heinrich¹  David K. Cureton¹  Sean P. J. Whelan¹  Amal A. Rahmeh² 

[1] Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts, United States of America;Program in Virology, Harvard Medical School, Boston, Massachusetts, United States of America

关键词: RNA synthesis;    Cytoplasmic inclusions;    Messenger RNA;    Vesicular stomatitis virus;    RNA transport;    Cytoplasm;    Viral replication;    RNA viruses;   

DOI  :  10.1371/journal.ppat.1000958

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Positive-strand and double-strand RNA viruses typically compartmentalize their replication machinery in infected cells. This is thought to shield viral RNA from detection by innate immune sensors and favor RNA synthesis. The picture for the non-segmented negative-strand (NNS) RNA viruses, however, is less clear. Working with vesicular stomatitis virus (VSV), a prototype of the NNS RNA viruses, we examined the location of the viral replication machinery and RNA synthesis in cells. By short-term labeling of viral RNA with 5′-bromouridine 5′-triphosphate (BrUTP), we demonstrate that primary mRNA synthesis occurs throughout the host cell cytoplasm. Protein synthesis results in the formation of inclusions that contain the viral RNA synthesis machinery and become the predominant sites of mRNA synthesis in the cell. Disruption of the microtubule network by treatment of cells with nocodazole leads to the accumulation of viral mRNA in discrete structures that decorate the surface of the inclusions. By pulse-chase analysis of the mRNA, we find that viral transcripts synthesized at the inclusions are transported away from the inclusions in a microtubule-dependent manner. Metabolic labeling of viral proteins revealed that inhibiting this transport step diminished the rate of translation. Collectively those data suggest that microtubule-dependent transport of viral mRNAs from inclusions facilitates their translation. Our experiments also show that during a VSV infection, protein synthesis is required to redirect viral RNA synthesis to intracytoplasmic inclusions. As viral RNA synthesis is initially unrestricted, we speculate that its subsequent confinement to inclusions might reflect a cellular response to infection.

【 授权许可】

CC BY