A GD HOMOLOGOUS GENE OF FELINE HERPESVIRUS TYPE-1 ENCODES A HEMAGGLUTININ (GP60)

A gene-encoding glycoprotein D (gD) homologue of feline herpesvirus ty pe 1 (FHV-1) was identified and sequenced. It was located within an Ec oRI 4.3-kbp fragment in the middle of the unique short region. The pri mary translation product of the gD homologous gene is predicted to con sist of 374 amino acids with a molecular weight (MW) of 43.2 kDa. Comp arative analysis among gD counterparts of other herpesviruses revealed that six cysteine residues which correlate with disulfide bond struct ure were conserved, and the amino acid sequences had homologies of 32. 6% with bovine herpesvirus type 1 glV, 29.1% with pseudorabies virus g p50, 28.3% with equine herpesvirus type 1 gD, and 22.0% with herpes si mplex virus type 1 gD. When the go homologue was expressed in COS cell s and examined by indirect immunofluorescence and immunoprecipitation assays, it was recognized only by monoclonal antibodies (MAbs) reactiv e with gp60 which have virus-neutralizing and hemagglutination (HA)-in hibition (HI) activities. This expressed product had a MW of approxima tely 60 kDa and was shown to be a hemagglutinin by HA and HI tests wit h the MAbs. These results suggest that the gD homologue of FHV-1 is a hemagglutinin. (C) 1994 Academic Press, Inc.