48 research outputs found
Localization of Glycosyl Enzymes and Nucleotide-Sugar Transporters in the Endoplasmic Reticulum and the Golgi Apparatus
Epitope mapping of human herpesvirus-7 gp65 using monoclonal antibodies.
Human herpesvirus (HHV)-7 encodes a unique 65-kDa heparin-binding glycoprotein,
designated gp65. This molecule is thought to play a role in virus attachment and
entry. To obtain reagents to map the structure and function of HHV-7 gp65, we
produced monoclonal antibodies to this molecule. Ten monoclonal antibodies
reacting with gp65 on ELISA were subdivided in four groups on the basis of their
isotype and differential reactivity with (i) native versus denatured forms of
gp65, and (ii) mature (virion-associated) versus immature (cell-associated) forms
of the molecule. We were able to map the binding epitopes for eight of these ten
antibodies, and these were found to cluster to one site on gp65 (amino acids
239-278); within this region, the antibodies reacted with at least three distinct
domains (244-251, 255-262, 263-278). The reasons for the apparent immunodominance
of this region are uncertain. Taken together, this panel of antibodies
constitutes an extensive and well-characterized set of HHV-7 specific antibodies
that may have utility for future analyses of the structure/function of gp65, and
for studies on the virus life cycl
Linkage of human cytomegalovirus glycoprotein gO variant groups identified from worldwide clinical isolates with gN genotypes, implications for disease associations and evidence for N-terminal sites of positive selection.
Previously, we identified the glycoprotein gO gene, UL74, as a hypervariable locus in the human cytomegalovirus (HCMV) genome [Virology 293 (2002) 281]. Here, we analyze gO from 50 isolates from congenitally infected newborns, transplant recipients, and HIV/AIDS patients from Italy, Australia, and UK. These are compared to four gO groups described from USA transplantation patients [J. Virol. 76 (2002) 10841]. Phylogenetic analyses identified seven genotypes. Divergence between genotypes was up to 55% and within 3%. Discrete linkage was shown between seven hypervariable gO and gN genotypes, but not with gB. This suggests interactions, while gN and gO are known to form complexes with distinct conserved glycoproteins gM, gH/gL, respectively, both are involved in fusogenic entry and exit. Codon-based maximum likelihood models showed evidence for sites of positive selection. Further analyses of disease relationships should take into account these newly defined gO/gN groups