Point mutations in EBV gH that abrogate or differentially affect B cell and epithelial cell fusion.
Cell fusion mediated by Epstein-Barr virus requires three conserved glycoproteins, gB and gHgL, but activation is cell type specific. B cell fusion requires interaction between MHC class II and a fourth virus glycoprotein, gp42, which complexes non-covalently with gHgL. Epithelial cell fusion requires interaction between gHgL and a novel epithelial cell coreceptor and is blocked by excess gp42. We show here that gp42 interacts directly with gH and that point mutations in the region of gH recognized by an antibody that differentially inhibits epithelial and B cell fusion significantly impact both the core fusion machinery and cell-specific events. Substitution of alanine for glycine at residue 594 completely abrogates fusion with either B cells or epithelial cells. Substitution of alanine for glutamic acid at residue 595 reduces fusion with epithelial cells, greatly enhances fusion with B cells and allows low levels of B cell fusion even in the absence of gL.
Wu
Liguo
L
Department of Microbiology and Immunology, Center for Molecular and Tumor Virology and Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
Hutt-Fletcher
Lindsey M
LM
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000821:virology; D002459:Cell Fusion; D002460:Cell Line; D004847:Epithelial Cells / Q000166:cytology* / Q000821:virology; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004854:Herpesvirus 4, Human / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D017354:Point Mutation / Q000235:genetics*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053586:Virus Internalization
C101688:BZLF2 protein, Herpesvirus 4, Human; D006023:Glycoproteins; D014764:Viral Proteins