Hydrophobic residues that form putative fusion loops of Epstein-Barr virus glycoprotein B are critical for fusion activity.
To test the importance of the hydrophobic residues within the putative Epstein-Barr virus (EBV) glycoprotein B (gB) fusion loops in membrane fusion, WY(112-113) and WLIW(193-196) were mutated into alanine, glutamic acid, or the analogous residues from herpes simplex virus type 1 (HSV-1) gB (HR and RVEA). All gB variants exhibited cell surface expression, demonstrating that the substitutions did not perturb gB trafficking. None of six gB variants was, however, capable of mediating fusion with either epithelial or B cells. These data demonstrate that the bulky and hydrophobic EBV loop residues, which differ from the more hydrophilic HSV-1 residues and appear more compatible with membrane insertion, are essential for EBV gB-dependent fusion.
Backovic
Marija
M
Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA.
Jardetzky
Theodore S
TS
Longnecker
Richard
R
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D001402:B-Lymphocytes / Q000821:virology; D002459:Cell Fusion; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry; D004847:Epithelial Cells / Q000821:virology; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D021381:Protein Transport; D016415:Sequence Alignment; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*
C060207:Epstein-Barr virus glycoprotein gp110; D014764:Viral Proteins