title: Characterization of the Epstein-Barr virus glycoprotein BMRF-2.
abstract: Epstein-Barr virus (EBV) BMRF-2 protein interaction with the beta1 family of integrins plays an important role in EBV infection of polarized oral epithelial cells. In this work, we characterized BMRF-2 protein expression in EBV-infected B lymphoblastoid and polarized oral epithelial cells, and in hairy leukoplakia (HL) epithelium. BMRF-2 expression in B cells and polarized oral epithelial cells was associated with the EBV lytic infection. In these cells, BMRF-2 is efficiently transported to the cell membrane and its integrin binding Arg-Gly-Asp (RGD) motif is exposed on the cell surface. BMRF-2 is highly expressed in HL epithelium and accumulates at the lateral border of oral keratinocytes. In EBV-infected polarized oral epithelial cells, this protein is transported to the basolateral membranes and co-localized with beta1 integrin. These data suggest that BMRF-2 may play an important role in cell-to-cell spread of EBV within the oral epithelium. BMRF-2 is glycosylated through O-linked oligosaccharides; it forms oligomers and is associated with the virion envelope. Its C-terminal tail is localized in the cytoplasm. We found that beta1, alpha5, and alpha3 integrins are present in purified EBV virions. We show that BMRF-2 is a ligand for beta1, alpha5, alpha3, and alphav integrins and our data are consistent with a role for BMRF-2 in viral lytic infection.
authors.affiliation: Department of Medicine, University of California, San Francisco, USA.
authors.forename: Jianqiao
authors.initials: J
authors.lastname: Xiao
authors.forename: Joel M
authors.initials: JM
authors.lastname: Palefsky
authors.forename: Rossana
authors.initials: R
authors.lastname: Herrera
authors.forename: Sharof M
authors.initials: SM
authors.lastname: Tugizov
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000821:virology; D002144:Callithrix; D004847:Epithelial Cells / Q000378:metabolism; D015967:Gene Expression Regulation, Viral; D006801:Humans; D016023:Integrins / Q000378:metabolism; D017733:Leukoplakia, Hairy / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: C109482:BMRF-2 protein, Human herpesvirus 4; D016023:Integrins; D008562:Membrane Glycoproteins; D014764:Viral Proteins