The glycoprotein B genes of Marek's disease virus serotypes 2 and 3: identification and expression by recombinant fowlpox viruses.
The nucleotide sequences of the glycoprotein B (gB) genes of Marek's disease virus (MDV) serotypes 2 and 3 were determined (gB-2 and gB-3, respectively). The genomic locations of these genes coincide with that of the gB gene of serotype 1 MDV (gB-1). Alignment with gB-1 (Ross et al., 1989, J. Gen. Virol. 70, 1789-1804) revealed predicted amino acid identities of 83 and 82% for gB-2 and gB-3, respectively. Excluding the predicted N-terminal signal sequences, 8 of 9 potential N-linked glycosylation sites and all 10 cysteine residues in gB-1 are conserved in both gB-2 and gB-3. In addition, the putative proteolytic cleavage sites for processing of precursors (gp100s) to gp60s and gp49s are conserved among the three gB homologs. Fowlpox virus (FPV) recombinants expressing either the gB-2 or the gB-3 gene were constructed. We detected expression of authentic gB-2 and gB-3 complexes in cells infected with these FPV recombinants. Digestion of immunoprecipitated gB-1 and gB-3 with endoglycosidases revealed that both gp60s are modified by the additions of O-glycans and complex carbohydrates after cleavage of gp100s, while gp100s and gp49s contain only high-mannose carbohydrates. We confirm that the size differences between gB-1 and gB-3 complexes are due to different carbohydrate modifications.
Yoshida
S
S
USDA-Agricultural Research Service, Avian Disease and Oncology Laboratory, East Lansing, Michigan 48823.
Lee
L F
LF
Yanagida
N
N
Nazerian
K
K
D000595:Amino Acid Sequence; D000956:Antigens, Viral / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D001483:Base Sequence; D050260:Carbohydrate Metabolism; D005587:Fowlpox virus / Q000235:genetics; D015870:Gene Expression; D005814:Genes, Viral / Q000235:genetics*; D006026:Glycoside Hydrolases / Q000378:metabolism; D008381:Herpesvirus 2, Gallid / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012703:Serotyping; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism
D000956:Antigens, Viral; D011134:Polysaccharides; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; C072811:glycoprotein B, Marek's disease virus; D006026:Glycoside Hydrolases