title: Subcellular location and topology of severe acute respiratory syndrome coronavirus envelope protein.
abstract: Severe acute respiratory syndrome (SARS) coronavirus (CoV) envelope (E) protein is a transmembrane protein. Several subcellular locations and topological conformations of E protein have been proposed. To identify the correct ones, polyclonal and monoclonal antibodies specific for the amino or the carboxy terminus of E protein, respectively, were generated. E protein was mainly found in the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) of cells transfected with a plasmid encoding E protein or infected with SARS-CoV. No evidence of E protein presence in the plasma membrane was found by using immunofluorescence, immunoelectron microscopy and cell surface protein labeling. In addition, measurement of plasma membrane voltage gated ion channel activity by whole-cell patch clamp suggested that E protein was not present in the plasma membrane. A topological conformation in which SARS-CoV E protein amino terminus is oriented towards the lumen of intracellular membranes and carboxy terminus faces cell cytoplasm is proposed.
authors.affiliation: Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Nieto-Torres
authors.forename: Marta L
authors.initials: ML
authors.lastname: Dediego
authors.forename: Enrique
authors.initials: E
authors.lastname: Alvarez
authors.forename: Jose M
authors.initials: JM
authors.lastname: Jiménez-Guardeño
authors.forename: Jose A
authors.initials: JA
authors.lastname: Regla-Nava
authors.forename: Mercedes
authors.initials: M
authors.lastname: Llorente
authors.forename: Leonor
authors.initials: L
authors.lastname: Kremer
authors.forename: Shen
authors.initials: S
authors.lastname: Shuo
authors.forename: Luis
authors.initials: L
authors.lastname: Enjuanes
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000821:virology; D006056:Golgi Apparatus / Q000378:metabolism / Q000821:virology; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism / Q000821:virology*; D008969:Molecular Sequence Data; D021381:Protein Transport; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics / Q000378:metabolism*; D045169:Severe Acute Respiratory Syndrome / Q000378:metabolism / Q000821:virology*; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*; D000086082:Viroporin Proteins
chemical_list: C501689:E protein, SARS coronavirus; D014759:Viral Envelope Proteins; D000086082:Viroporin Proteins