title: 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.affiliation: Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Jimenez-Guardeño
authors.affiliation: Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Nieto-Torres
authors.affiliation: Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Marta L
authors.initials: ML
authors.lastname: DeDiego
authors.affiliation: Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Regla-Nava
authors.affiliation: Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Raul
authors.initials: R
authors.lastname: Fernandez-Delgado
authors.affiliation: Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Castaño-Rodriguez
authors.affiliation: Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Enjuanes
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002522:Chlorocebus aethiops; D004195:Disease Models, Animal; D005260:Female; D006790:Host-Parasite Interactions / Q000502:physiology*; D047468:Immunoprecipitation; D051379:Mice; D008807:Mice, Inbred BALB C; D018613:Microscopy, Confocal; D020411:Oligonucleotide Array Sequence Analysis; D054731:PDZ Domains / Q000502:physiology*; D016133:Polymerase Chain Reaction; D045473:Severe acute respiratory syndrome-related coronavirus / Q000472:pathogenicity*; D045169:Severe Acute Respiratory Syndrome / Q000378:metabolism / Q000821:virology*; D015398:Signal Transduction / Q000502:physiology; D053676:Syntenins / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000378:metabolism*; D000086082:Viroporin Proteins; D014774:Virulence; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: C501689:E protein, SARS coronavirus; C484513:Sdcbp protein, mouse; D053676:Syntenins; D014759:Viral Envelope Proteins; D000086082:Viroporin Proteins; D048051:p38 Mitogen-Activated Protein Kinases