Journal Article

The PDZ-Binding Motif of Severe Acute Respiratory Syndrome Coronavirus Envelope Protein Is a Determinant of Viral Pathogenesis

Fernandez-Delgado, Raul, Nieto-Torres, Jose L., Castaño-Rodriguez, Carlos, Enjuanes, Luis, Jimenez-Guardeño, Jose M., DeDiego, Marta L., Regla-Nava, Jose A.

2014

Overview

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.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Animals / Biology and Life Sciences / Blotting, Western / Care and treatment / Cellular proteins / Chlorocebus aethiops / Development and progression / Disease Models, Animal / Experiments / Female / Health aspects / Host-Parasite Interactions - physiology / Immunoprecipitation / Infections / Laboratories / Medicine and Health Sciences / Mice / Mice, Inbred BALB C / Microscopy, Confocal / Mortality / Oligonucleotide Array Sequence Analysis / p38 Mitogen-Activated Protein Kinases - metabolism / Pathogenesis / PDZ Domains - physiology / Physiological aspects / Polymerase Chain Reaction / Protein binding / Protein-protein interactions / Proteins / Respiratory diseases / Rodents / SARS Virus - pathogenicity / Severe acute respiratory syndrome / Severe Acute Respiratory Syndrome - metabolism / Severe Acute Respiratory Syndrome - virology / Signal Transduction - physiology / Syntenins - metabolism / Two-Hybrid System Techniques / Vero Cells / Viral Envelope Proteins - metabolism / Viroporin Proteins / Virulence / Viruses