Cleavage of Epstein-Barr virus glycoprotein B is required for full function in cell-cell fusion with both epithelial and B cells.
Glycoprotein B (gB) homologues within the herpesvirus family display high sequence conservation, and a number of gB homologues contain a cleavage motif R-X-K/R-R recognized by the cellular protease furin. Epstein-Barr virus (EBV) gB contains this motif and cleaved gB is found in EBV virions. To determine the functional significance of this cleavage motif in EBV gB, a deletion mutant (gB Deltafurin) was created lacking the motif. This cleavage mutant was expressed well in cell culture but was not cleaved. Experiments examining gB Deltafurin in a cell-fusion assay revealed that fusion was reduced by 52 % in epithelial and 28 % in B cells when compared with wild-type EBV gB. This decrease in cell-cell fusion is similar to that observed with multiple alphaherpesvirus gB cleavage mutants and supports a conserved function for cleaved gB.
Sorem
Jessica
J
Department of Microbiology and Immunology, The Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
Longnecker
Richard
R
Department of Microbiology and Immunology, The Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000821:virology*; D002459:Cell Fusion; D004847:Epithelial Cells / Q000821:virology*; D017353:Gene Deletion; D004854:Herpesvirus 4, Human / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D008561:Membrane Fusion; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
C060207:Epstein-Barr virus glycoprotein gp110; D014764:Viral Proteins