Infectious bronchitis virus nonstructural protein 4 alone induces membrane pairing

Doyle, N., Neuman, B. W., Simpson, J., Hawes, P. C., Mantell, J., Verkade, P., Alrashedi, H. and Maier, H. J. (2018) Infectious bronchitis virus nonstructural protein 4 alone induces membrane pairing. Viruses, 10 (9). 477. ISSN 1999-4915 doi: 10.3390/v10090477

Abstract/Summary

Positive-strand RNA viruses, such as coronaviruses, induce cellular membrane rearrangements during replication to form replication organelles allowing for efficient viral RNA synthesis. Infectious bronchitis virus (IBV), a pathogenic avian of significant importance to the global poultry industry, has been shown to induce the formation of double membrane vesicles (DMVs), zippered endoplasmic reticulum (zER) and tethered vesicles, known as spherules. These membrane rearrangements are virally induced; however, it remains unclear which viral proteins are responsible. In this study, membrane rearrangements induced when expressing viral non-structural proteins (nsps) from two different strains of IBV were compared. Three non-structural transmembrane proteins, nsp3, nsp4, and nsp6, were expressed in cells singularly or in combination and the effects on cellular membranes investigated using electron microscopy and electron tomography. In contrast to previously studied coronaviruses, IBV nsp4 alone is necessary and sufficient to induce membrane pairing; however, expression of the transmembrane proteins together was not sufficient to fully recapitulate DMVs. This indicates that although nsp4 is able to singularly induce membrane pairing, further viral or host factors are required in order to fully assemble IBV replicative structures. This study highlights further differences in the mechanism of membrane rearrangements between members of the coronavirus family.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/79458
Identification Number/DOI	10.3390/v10090477
Refereed	Yes
Divisions	Life Sciences > School of Biological Sciences > Biomedical Sciences
Uncontrolled Keywords	coronavirus, electron tomography, infectious bronchitis virus, membrane rearrangements, non-structural protein, nsp3, nsp4, paired membranes, zippered ER
Publisher	MDPI
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