Sequence characteristics of a gene in equine herpesvirus 1 homologous to glycoprotein H of herpes simplex virus

Abstract

A gene in equine herpesvirus 1 (EHV-1, equine abortion virus) homologous to the glycoprotein H gene of herpes simplex virus (HSV) was identified and characterised by its nucleotide and derived amino acid sequence. The EHV-1 gH gene is located at 0.47-0.49 map units and contains an open reading frame capable of specifying a polypeptide of 848 amino acids, including N- and C-terminal hydrophobic domains consistent with signal and membrane anchor regions respectively, and 11 potential sites for N-glycosylation. Alignment of the amino acid sequence with those published for HSV gH, varicella zoster virus gpIII, Epstein Barr virus gp85 and human cytomegalovirus p86 shows similarity of the EHV gene with the 2 other alpha-herpesviruses over most of the polypeptide, but only the C-terminal half could be aligned for all 5 viruses. The identical positioning of 6 cysteine residues and a number of highly conserved amino acid motifs supports a common evolutionary origin of this gene and is consistent with its role as an essential glycoprotein of the herpesvirus family. An origin of replication is predicted to occur at approximately 300 nucleotides downstream of the EHV-1 gH coding region, on the basis of similarity to other herpesvirus origins.

Characterization of the major glycoproteins of equine herpesviruses 4 and 1 and asinine herpesvirus 3 using monoclonal antibodies

“…4 it is clear that gp2, gpl3, gpl4, gpl8 and an as yet unidentified glycoprotein of Mr 120K (EHV-1) or 116K (EHV-4) all elicit significant levels of antibody in the naturally infected host. It is possible that the glycoprotein at 120K is the EHV-1 gH homologue described recently which is likely to occur at approximately this Mr (Robertson et al, 1990). Gpl0 was not identified on non-reducing polyacrylamide gels when [l*C]glucosamine-labelled EHV-1 antigens were immunoprecipitated using MAb 13A9, whereas it was easily detected by Western blotting (Fig.…”

“…EHV-1 gpl3 and gpl4 have been identified as homologues of HSV gC and gB respectively Allen & Yeargan, 1987;Meredith et al, 1989;Whalley et al, 1989). Recently, DNA sequence analysis has revealed EHV-1 and EHV-4 gH homologues (Robertson et al, 1990;Nicolson et al, 1990b), although it is not yet known whether any of the EHV-1 glycoproteins described above correspond to gH. A detailed understanding of the glycoproteins of EHV-4, EHV-1 and AHV-3, particularly their immunogenicity in the naturally infected host, is of significance in the search for more appropriate vaccines and diagnostic reagents for EHV-4 and EHV-1.…”

A mutational analysis of the DNA-binding domain of the herpes simplex virus type 1 UL9 protein

“…The presence of DNA sequence motifs identical to that recognized by the HSV-1 UL9 protein either adjacent to, or within, A + T-rich palindromes is a feature shared by known or presumed replication origins of other members of the alphaherpesvirus subfamily (Stow & Davison, 1986;Baumann et al, 1989;Nicolson et al, 1990;Robertson et al, 1991 ;Klupp et al, 1992). In the case of varicella-zoster virus (VZV) and equine herpesvirus 1 (EHV-1), DNA sequence determination has revealed the presence of UL9 gene homologues (genes 51 and 53, respectively;Davison & Scott, 1986;McGeoch et al, 1988;Telford et al, 1992).…”

Identification and sequence analysis of the homologues of the herpes simplex virus type 1 glycoprotein H in Marek's disease virus and the herpesvirus of turkeys

“…2. This compares to 11 such sites in the VZV and EHV-1 and -4 gHs, eight in herpesvirus saimiri (HVS), seven in HSV-1, six in HCMV, five in EBV and three in PRV (Keller et al, 1987;Robertson et al, 1991;Nicolson et al, 1990;Gompels et al, 1988;Gompels & Minson, 1986;McGeoch & Davison, 1986;Cranage et al, 1988;Baer et al, 1984;Klupp & Mettenleiter, 1991). Only one of these sites shows conservation of position in all eight gH sequences.…”

“…Further primer extension sequencing of BamHI-F itself, to provide data for the 500 bp downstream of the MDV gH gene, revealed no direct repeat elements or putative replication origin sequences, as has been found in this position for equine herpesvirus (EHV)-I and -4 and pseudorabies virus (PRV) (Robertson et al, 1991;Nicolson et al, 1990;Klupp & Mettenleiter, 1991). The repeats in PRV are located 440 bp downstream of the gH stop codon and thus our results do not preclude the existence of an equivalent region further downstream in MDV.…”