The PDZ-binding motif of severe acute respiratory syndrome coronavirus envelope protein is a determinant of viral pathogenesis.

Abstract

A recombinant severe acute respiratory syndrome coronavirus (SARS-CoV) lacking the envelope (E) protein is attenuated in vivo. Here we report that E protein PDZ-binding motif (PBM), a domain involved in protein-protein interactions, is a major determinant of virulence. Elimination of SARS-CoV E protein PBM by using reverse genetics caused a reduction in the deleterious exacerbation of the immune response triggered during infection with the parental virus and virus attenuation. Cellular protein syntenin was identified to bind the E protein PBM during SARS-CoV infection by using three complementary strategies, yeast two-hybrid, reciprocal coimmunoprecipitation and confocal microscopy assays. Syntenin redistributed from the nucleus to the cell cytoplasm during infection with viruses containing the E protein PBM, activating p38 MAPK and leading to the overexpression of inflammatory cytokines. Silencing of syntenin using siRNAs led to a decrease in p38 MAPK activation in SARS-CoV infected cells, further reinforcing their functional relationship. Active p38 MAPK was reduced in lungs of mice infected with SARS-CoVs lacking E protein PBM as compared with the parental virus, leading to a decreased expression of inflammatory cytokines and to virus attenuation. Interestingly, administration of a p38 MAPK inhibitor led to an increase in mice survival after infection with SARS-CoV, confirming the relevance of this pathway in SARS-CoV virulence. Therefore, the E protein PBM is a virulence domain that activates immunopathology most likely by using syntenin as a mediator of p38 MAPK induced inflammation.

• Authors: Jose M Jimenez-Guardeño, Jose L Nieto-Torres, Marta L DeDiego, Jose A Regla-Nava, Raul Fernandez-Delgado, Carlos Castaño-Rodriguez, Luis Enjuanes
• Journal: PLoS pathogens (PLoS Pathog) Vol. 10 Issue 8 Pg. e1004320 (Aug 2014) ISSN: 1553-7374 [Electronic] United States
• PMID: 25122212 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• E protein, SARS coronavirus
• Sdcbp protein, mouse
• Syntenins
• Viral Envelope Proteins
• Viroporin Proteins
• p38 Mitogen-Activated Protein Kinases

Topics

• Animals
• Blotting, Western
• Chlorocebus aethiops
• Disease Models, Animal
• Female
• Host-Parasite Interactions (physiology)
• Immunoprecipitation
• Mice
• Mice, Inbred BALB C
• Microscopy, Confocal
• Oligonucleotide Array Sequence Analysis
• PDZ Domains (physiology)
• Polymerase Chain Reaction
• Severe acute respiratory syndrome-related coronavirus (pathogenicity)
• Severe Acute Respiratory Syndrome (metabolism, virology)
• Signal Transduction (physiology)
• Syntenins (metabolism)
• Two-Hybrid System Techniques
• Vero Cells
• Viral Envelope Proteins (metabolism)
• Viroporin Proteins
• Virulence
• p38 Mitogen-Activated Protein Kinases (metabolism)