Elsevier

Virus Research

Volume 183, 21 April 2014, Pages 107-111
Virus Research

Short communication
Signal peptide cleavage from GP3 enabled by removal of adjacent glycosylation sites does not impair replication of equine arteritis virus in cell culture, but the hydrophobic C-terminus is essential

https://doi.org/10.1016/j.virusres.2014.02.005Get rights and content

Highlights

  • Glycosylation near the signal peptide of Gp3 from EAV prevents cleavage.

  • Recombinant viruses with cleaved signal peptide have no growth defect.

  • EAV with a deletion of the hydrophobic C-terminus reverted back to wild-type.

  • Results support our model: signal peptide is exposed to the lumen of the ER.

  • The C-terminus attaches Gp3 to membranes.

Abstract

The disulphide-linked GP2/3/4 spike of equine arteritis virus (EAV) is essential for virus entry. We showed recently that in transfected cells carbohydrates attached adjacent to the signal peptide of GP3 inhibit cleavage. Here we confirm this unique phenomenon in recombinant viruses with disabled glycosylation sites. Surprisingly, the infectivity of EAV containing GP3 with cleaved signal peptide was not impaired and GP3 with cleaved signal peptide associates with GP2/4 in virus particles. In contrast, viruses containing GP3 with deleted hydrophobic C-terminus rapidly reverted back to wild type. The data support our model that the signal peptide is exposed to the lumen of the ER and the C-terminus peripherally attaches GP3 to membranes.

Section snippets

Acknowledgements

Funding was provided by the EU (FP7, Initial Training network “Virus entry”). We thank Eric Snijder (Virology, University of Leiden) for the provision of the cDNA clone of EAV and for anti-E antibodies, Peter Rottier (Virology, University of Utrecht) for supplying anti-GP3 antibodies, Udeni Balasuriya (Gluck Equine Research Center, University of Kentucky) for anti-GP2 antiserum and Bastian Thaa for reading of the manuscript.

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