This Article Full Text (PDF) Other Versions of this Article: JVI.01052-08v1 82/22/11318    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Siu, Y L. Articles by Nal, B. PubMed PubMed Citation Articles by Siu, Y L. Articles by Nal, B.

 Previous Article  |  Next Article 

J. Virol. doi:10.1128/JVI.01052-08
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

The M, E and N structural proteins of the SARS coronavirus are required for efficient assembly, trafficking and release of virus-like particles

From the HKU-Pasteur Research Centre, 8 Sassoon Road, Hong Kong SAR, China; Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China; Department of Microbiology, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China; Institut Pasteur, Unité de Génétique Moléculaire des Virus Respiratoires, URA-CNRS 3015, 25-28 Rue du Docteur Roux, 75724, Paris Cedex 15, France; Department of Anatomy; The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China; CombinatoRx-Singapore Pte Ltd, 11 Biopolis Way, 138667 Singapore

^* To whom correspondence should be addressed. Email: bnal{at}hku.hk.

	Abstract

Production of virus-like particles (VLPs) constitutes a relevant and safe model to study molecular determinants of virion egress. The minimal requirement for assembly of VLPs for the coronavirus responsible for severe acute respiratory symdrome in humans (SARS-CoV) is still controversial. Recent studies have described that SARS-CoV VLP formation depends on either M and E or M and N proteins. Here we show that both E and N must be co-expressed with M for efficient production and release of VLPs by transfected Vero E6 cells. This result suggests that the mechanism of SARS-CoV assembly differs from other studied coronaviruses, which only require M and E for VLP formation. When co-expressed, the native envelope trimeric S glycoprotein is incorporated onto VLPs. Interestingly, when a fluorescent protein tag is added to the C-terminal end of N or S, but not M, the chimeric viral proteins can be assembled within VLPs and allow visualization of VLP production and trafficking in living cells by state of the art imaging technologies. Fluorescent VLPs will be used further to investigate the role of cellular machineries during SARS-CoV egress.