Identification and characterization of murine gammaherpesvirus 68 gp150: a virion membrane glycoprotein.
Murine gammaherpesvirus 68 (MHV-68) is a naturally occurring virus of murid rodents which displays pathobiological characteristics similar to those of other gammaherpesviruses, including Epstein-Barr virus (EBV). However, unlike EBV and many other gammaherpesviruses, MHV-68 replicates in epithelial cells in vitro and infects laboratory strains of mice and therefore provides a good model for the study of gammaherpesviruses. Studies of sequences around the center of the MHV-68 genome identified a gene (designated BPRF1 for BamHI P fragment rightward open reading frame 1) whose putative product had motifs reminiscent of a transmembrane glycoprotein. All other gammaherpesviruses have a glycoprotein in this genomic position, but the BPRF1 gene showed sequence homology with only the EBV membrane antigen gp340/220. Biochemical analysis showed that the product of BPRF1 was a glycoprotein present on the surface of infected cells, and immunoelectron microscopy showed that it was present in the virus particle. In addition, antibodies to the BPRF1 product raised by using a bacterial fusion protein neutralized the virus in the absence of complement. The predominant molecular weights of the protein were 150,000 and 130,000. Pulse-chase analysis and endoglycosidase-H digestion showed that the 130,000-molecular-weight form was a precursor of the 150,000-molecular-weight form, and cell surface labelling showed that the 150,000-molecular-weight form alone was on the cell surface. We therefore named the protein gp150. Since gp150 is the first virion-associated glycoprotein and neutralizing determinant of MHV-68 to be characterized, it provides a valuable tool for the future study of virus-host interactions.
Stewart
J P
JP
Department of Veterinary Pathology, The University of Edinburgh, United Kingdom.
Janjua
N J
NJ
Pepper
S D
SD
Bennion
G
G
Mackett
M
M
Allen
T
T
Nash
A A
AA
Arrand
J R
JR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018142:Gammaherpesvirinae / Q000737:chemistry* / Q000235:genetics; D005814:Genes, Viral; D008562:Membrane Glycoproteins / Q000032:analysis*; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D014759:Viral Envelope Proteins / Q000032:analysis* / Q000276:immunology; D014771:Virion / Q000737:chemistry*
D008562:Membrane Glycoproteins; D014759:Viral Envelope Proteins