Identification of equine herpesvirus 4 glycoprotein G: a type-specific, secreted glycoprotein.
Abstract: Equine herpesvirus 4 (EHV4) glycoproteins of M(r) 63K and 250K were identified in the supernatant of infected cell cultures. The 63K glycoprotein was type-specific; that is, it reacted with monospecific sera from horses that had been immunized or infected with EHV4, but not with monospecific sera from horses immunized or infected with EHV1, a closely related alphaherpesvirus. It was postulated that the secreted protein may be the homologue of similarly secreted glycoproteins of herpes simplex virus 2 glycoprotein G (HSV2 gG) and pseudorabies virus (PRV) gX, which is the homologue of HSV2 gG. The US region of the EHV4 genome, toward the internal repeat structure, was sequenced. Four open reading frames (ORFs) were identified of which ORF4 showed 52% similarity to the gene-encoding PRV gX in a 650-nucleotide region. ORF4 coded for a primary translational product of 405 amino acids which has a predicted size of 44K. The amino acid sequence of ORF4 showed 28% identity with PRV gX and 16% identity with HSV2 gG, although significantly greater identity was observed in the N-terminal region including the conservation of 4 cysteine residues. Accordingly, we designate ORF4 as EHV4 gG. The predicted amino acid sequence of the EHV4 gG showed characteristics of an envelope glycoprotein. Expression of the entire EHV4 gG gene in the bacterial expression vector pGEX-3X produced a type-specific fusion protein of M(r) 70K of which the gG portion composes 43K. Antibody that was affinity purified from selected portions of Western blots containing the 70K gG fusion protein reacted with the 63K secreted glycoprotein. Conversely, antibody affinity purified to the 63K secreted product reacted with the 70K gG fusion protein. These results showed that the EHV4 63K secreted glycoprotein was EHV4 gG, the third alphaherpesvirus gG homologue known to be, at least in part, secreted. The type-specificity of this glycoprotein provides, for the first time, the opportunity to differentiate between antibodies present in polyclonal sera from EHV4, EHV1, and dual-infected horses and this has important implications for understanding the epidemiology of these viruses.
Publication Date: 1992-09-01 PubMed ID: 1529525DOI: 10.1016/0042-6822(92)91200-eGoogle Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research article discusses the identification of a type-specific, secreted glycoprotein (EHV4 gG) in Equine herpesvirus 4 (EHV4), which provides an opportunity to differentiate between antibodies present in horses affected by EHV4, EHV1, or both, which is crucial for understanding the epidemiology of these viruses.
Identification of EHV4 Proteins
- The researchers were able to identify EHV4 glycoproteins of M(r) 63K and 250K in the supernatant of infected cell cultures.
- The 63K glycoprotein was found to be type-specific as it reacted with monospecific sera from horses infected or immunized with EHV4 but failed to react with similar sera from horses infected or immunized with EHV1.
- This suggested that this secreted protein might be similar to other secreted glycoproteins of herpes simplex virus 2 glycoprotein G (HSV2 gG) and pseudorabies virus (PRV) gX.
Genomic Analysis of EHV4
- In the US region of the EHV4 genome directed towards the internal repeat structure, four open reading frames (ORFs) were identified.
- Of these, ORF4 showed a 52% similarity to the gene-encoding PRV gX in a region comprising 650 nucleotides.
- ORF4 coded for a primary translational product of 405 amino acids which had a predicted size of 44K.
- A comparison of the amino acid sequence of ORF4 showed 28% identity with PRV gX and a 16% identity with HSV2 gG. However, the identity was significantly higher in the N-terminal region, which also showed a conservation of 4 cysteine residues.
Expression and Identification of EHV4 gG
- Expression of the entire gene for EHV4 gG in the bacterial expression vector pGEX-3X resulted in a type-specific fusion protein of M(r) 70K, with the gG part being 43K.
- Antibodies affinity-purified from selected portions of the 70K gG fusion protein reacted with the 63K secreted glycoprotein; and vice-versa, demonstrating that the 63K secreted glycoprotein was indeed EHV4 gG.
Implications of the Research
- The research findings imply that the type-specificity of this glycoprotein provides an opportunity to differentiate between antibodies present in polyclonal sera from horses infected with EHV4, EHV1, and those with dual infection.
- This ability to differentiate has significant implications for understanding the epidemiology of these viruses in horses.
Cite This Article
APA
Crabb BS, Nagesha HS, Studdert MJ.
(1992).
Identification of equine herpesvirus 4 glycoprotein G: a type-specific, secreted glycoprotein.
Virology, 190(1), 143-154.
https://doi.org/10.1016/0042-6822(92)91200-e Publication
Researcher Affiliations
- School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia.
MeSH Terms
- Amino Acid Sequence
- Animals
- Base Sequence
- Cell Line
- DNA, Viral
- Herpesviridae / chemistry
- Herpesviridae / genetics
- Herpesviridae / metabolism
- Molecular Sequence Data
- Restriction Mapping
- Viral Envelope Proteins / chemistry
- Viral Envelope Proteins / genetics
- Viral Envelope Proteins / metabolism
Citations
This article has been cited 16 times.- Laval K, Enquist LW. The Neuropathic Itch Caused by Pseudorabies Virus. Pathogens 2020 Mar 31;9(4).
- Oladunni FS, Horohov DW, Chambers TM. EHV-1: A Constant Threat to the Horse Industry. Front Microbiol 2019;10:2668.
- Azab W, El-Sheikh A, Abdel-Gawad A. In vitro characterization of EHV-4 gG-deleted mutant. Virus Genes 2012 Feb;44(1):109-11.
- Zhao Y, Wang JW, Ma B, Liu F. Molecular analysis of duck enteritis virus US3, US4, and US5 gene. Virus Genes 2009 Apr;38(2):289-94.
- Bryant NA, Davis-Poynter N, Vanderplasschen A, Alcami A. Glycoprotein G isoforms from some alphaherpesviruses function as broad-spectrum chemokine binding proteins. EMBO J 2003 Feb 17;22(4):833-46.
- Schneider PA, Hatalski CG, Lewis AJ, Lipkin WI. Biochemical and functional analysis of the Borna disease virus G protein. J Virol 1997 Jan;71(1):331-6.
- Kliche S, Stitz L, Mangalam H, Shi L, Binz T, Niemann H, Briese T, Lipkin WI. Characterization of the Borna disease virus phosphoprotein, p23. J Virol 1996 Nov;70(11):8133-7.
- Keil GM, Engelhardt T, Karger A, Enz M. Bovine herpesvirus 1 U(s) open reading frame 4 encodes a glycoproteoglycan. J Virol 1996 May;70(5):3032-8.
- Su HK, Fetherston JD, Smith ME, Courtney RJ. Orientation of the cleavage site of the herpes simplex virus glycoprotein G-2. J Virol 1993 May;67(5):2954-9.
- Nagesha HS, Crabb BS, Studdert MJ. Analysis of the nucleotide sequence of five genes at the left end of the unique short region of the equine herpesvirus 4 genome. Arch Virol 1993;128(1-2):143-54.
- Riggio MP, Onions DE. DNA sequence of a gene cluster in the equine herpesvirus-4 genome which contains a newly identified herpesvirus gene encoding a membrane protein. Arch Virol 1993;133(1-2):171-8.
- Hatalski CG, Kliche S, Stitz L, Lipkin WI. Neutralizing antibodies in Borna disease virus-infected rats. J Virol 1995 Feb;69(2):741-7.
- Crabb BS, MacPherson CM, Reubel GH, Browning GF, Studdert MJ, Drummer HE. A type-specific serological test to distinguish antibodies to equine herpesviruses 4 and 1. Arch Virol 1995;140(2):245-58.
- Crabb BS, Studdert MJ. Epitopes of glycoprotein G of equine herpesviruses 4 and 1 located near the C termini elicit type-specific antibody responses in the natural host. J Virol 1993 Oct;67(10):6332-8.
- Wilson L, Neilan J, Brady I, Coyle D, Cullinane AA. Use of lambda gt11 to identify antigenic components of equine herpesvirus 4. Virus Genes 1994 Mar;8(2):159-63.
- Ficorilli N, Studdert MJ, Crabb BS. The nucleotide sequence of asinine herpesvirus 3 glycoprotein G indicates that the donkey virus is closely related to equine herpesvirus 1. Arch Virol 1995;140(9):1653-62.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
