title: Identification of two amino acid residues on Ebola virus glycoprotein 1 critical for cell entry.
abstract: Using site-directed mutagenesis and retroviral vector pseudotyping of the wild type or mutated glycoprotein of Zaire ebolavirus (ZEBOV), we analyzed 15 conserved residues in the N-terminus of the filovirus glycoprotein 1 (GP1) in order to identify residues critical for cell entry. Results from infectivity assays and Western blot analyses identified two phenylalanine residues at positions 88 and 159 that appear to be critical for ZEBOV entry in vitro. We extended this observation by introduction of alanines at either position 88 or 159 of Ivory Coast Ebolavirus (CIEBOV) and observed the same phenotype. Further, we showed that introduction of each of the two mutations in a recombinant full-length clone of ZEBOV (Mayinga strain) that also carried the coding sequence for GFP could not be rescued, suggesting the mutants rendered the virus non-infectious. The two phenylalanines that are critical for both ZEBOV and CIEBOV entry are found in two linear domains of GP1 that are highly conserved among filoviruses, and thus could provide a target for rational development of broadly cross-protective vaccines or antiviral therapies.
authors.affiliation: Gene Transfer and Immunogenicity Branch, Division of Cellular, Tissue and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
authors.forename: Onesmo M
authors.initials: OM
authors.lastname: Mpanju
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Towner
authors.forename: Jason E
authors.initials: JE
authors.lastname: Dover
authors.forename: Stuart T
authors.initials: ST
authors.lastname: Nichol
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Wilson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D029043:Ebolavirus / Q000502:physiology*; D019142:Hemorrhagic Fever, Ebola / Q000821:virology*; D006801:Humans; D008969:Molecular Sequence Data; D010649:Phenylalanine / Q000235:genetics / Q000502:physiology*; D017354:Point Mutation; D017434:Protein Structure, Tertiary / Q000502:physiology; D016415:Sequence Alignment; D014759:Viral Envelope Proteins / Q000235:genetics / Q000502:physiology*; D014779:Virus Replication
chemical_list: D014759:Viral Envelope Proteins; C113189:envelope glycoprotein, Ebola virus; D010649:Phenylalanine