Analyze Diet
Journal of virology1997; 71(7); 4904-4914; doi: 10.1128/JVI.71.7.4904-4914.1997

The ICP0 protein of equine herpesvirus 1 is an early protein that independently transactivates expression of all classes of viral promoters.

Abstract: To assess the role of the equine herpesvirus type 1 (EHV-1) ICP0 protein (EICP0) in gene regulation, a variety of molecular studies on the EICP0 gene and gene products of both the attenuated cell culture-adapted Kentucky A (KyA) strain and the Ab4p strain were conducted. These investigations revealed that (i) the ICP0 open reading frame (ORF) of the KyA virus strain is 1,257 bp in size and would encode a protein of 419 amino acids, and in comparison to the ICP0 gene (ORF63) of the Ab4p strain of 1,596 bp (E. A. Telford, M. S. Watson, K. McBride, and A. J. Davison, Virology 189:304-316, 1992), it has an internal in-frame deletion of 339 bp; (ii) one early transcript of 1.4 kb predicted to encode the EICP0 protein and a late transcript of 1.8 kb are detected in Northern blot analyses using probes containing the EICP0 ORF; (iii) the KyA EICP0 protein (50 kDa) and the Ab4p EICP0 protein (80 kDa) are expressed as several species of early proteins that are first detected at 3 to 4 h postinfection by Western blot analyses of infected-cell polypeptides, using an antiserum generated to a TrpE fusion protein that harbors amino acids 46 to 153 of the EICP0 protein; and (iv) the EICP0 protein of both EHV-1 strains is a potent transactivator of EHV-1 genes. Transient expression assays using a simian virus 40 expression construct of the EICP0 protein of the KyA strain showed that the EICP0 protein independently transactivated chloramphenicol acetyltransferase reporter constructs under the control of the immediate-early promoter (3.9-fold), the early thymidine kinase promoter (95-fold), the late (gamma1) IR5 promoter (85-fold), and the late (gamma2) glycoprotein K promoter (21-fold). The finding that the EICP0 protein of the KyA virus can function as an activator of gene expression indicates that amino acids corresponding to residues 319 to 431 of the Ab4p EICP0 protein are not essential for EICP0 transactivation of EHV-1 promoters.
Publication Date: 1997-07-01 PubMed ID: 9188552PubMed Central: PMC191720DOI: 10.1128/JVI.71.7.4904-4914.1997Google 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
  • U.S. Gov't
  • Non-P.H.S.
  • Research Support
  • U.S. Gov't
  • P.H.S.

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 study explores the role of the ICP0 protein of Equine Herpesvirus Type 1 (EHV-1) in gene regulation, with a special focus on the variations between the attenuated cell culture-adapted Kentucky A (KyA) strain and the Ab4p strain. It reveals that the EICP0 protein of EHV-1 can independently activate gene expression, despite having an internal in-frame deletion compared to the Ab4p strain’s ICP0 gene.

Methodology and Findings

  • The study opens with an analysis of the genetic specifics of each strain’s ICP0 protein. The KyA strain’s ICP0 open reading frame (ORF) measures 1,257 base pairs (bp) compared to the Ab4p strain’s 1,596 bp. The KyA strain’s EICP0 gene has an internal in-frame deletion of 339 bp in relation to the Ab4p’s ICP0 gene.
  • The researchers identified two transcripts related to the EICP0 protein—a 1.4 kb early transcript and a 1.8 kb late transcript—through Northern blot analyses using probes containing the EICP0 ORF.
  • Three to four hours after infection, early proteins expressed by the KyA and Ab4p EICP0 genes were detected. Western blot analyses discerned these proteins using an antiserum generated to a TrpE fusion protein encoding a fraction of the EICP0 protein.
  • The investigation confirms that EICP0 can effectively transactivate EHV-1 genes, suggesting its crucial role in gene regulation.

Functional Assessment of EICP0

  • Transient expression assays were conducted to evaluate the transactivation capacity of EICP0 from the KyA strain. This process entailed using a simian virus 40 expression construct of the KyA’s EICP0 protein.
  • The results demonstrated that the EICP0 protein could independently transactivate chloramphenicol acetyltransferase reporter constructs governed by four viral promoters.
  • This evidence suggests that within the EICP0 protein, residues 319 to 431, which are missing in the KyA variant due their internal in-frame deletion compared to the Ab4p strain’s gene, are not crucial for the transactivation of EHV-1 promoters.

Cite This Article

APA
Bowles DE, Holden VR, Zhao Y, O'Callaghan DJ. (1997). The ICP0 protein of equine herpesvirus 1 is an early protein that independently transactivates expression of all classes of viral promoters. J Virol, 71(7), 4904-4914. https://doi.org/10.1128/JVI.71.7.4904-4914.1997

Publication

ISSN: 0022-538X
NlmUniqueID: 0113724
Country: United States
Language: English
Volume: 71
Issue: 7
Pages: 4904-4914

Researcher Affiliations

Bowles, D E
  • Department of Microbiology and Immunology, Louisiana State University Medical Center, Shreveport 71130-3932, USA.
Holden, V R
    Zhao, Y
      O'Callaghan, D J

        MeSH Terms

        • Amino Acid Sequence
        • Animals
        • Base Sequence
        • Cell Line
        • DNA, Viral
        • Gene Expression Regulation, Viral
        • Genes, Viral
        • Molecular Sequence Data
        • Promoter Regions, Genetic
        • Rabbits
        • Sequence Analysis, DNA
        • Sequence Homology, Amino Acid
        • Sequence Homology, Nucleic Acid
        • Transcriptional Activation
        • Viral Proteins / genetics

        Grant Funding

        • AI-22001 / NIAID NIH HHS

        References

        This article includes 65 references
        1. Elliott G, O'Hare P. Equine herpesvirus 1 gene 12, the functional homologue of herpes simplex virus VP16, transactivates via octamer sequences in the equine herpesvirus IE gene promoter.. Virology 1995 Oct 20;213(1):258-62.
          pubmed: 7483272doi: 10.1006/viro.1995.1568google scholar: lookup
        2. Nagpal S, Ostrove JM. Characterization of a potent varicella-zoster virus-encoded trans-repressor.. J Virol 1991 Oct;65(10):5289-96.
        3. Everett RD, Orr A, Elliott M. High level expression and purification of herpes simplex virus type 1 immediate early polypeptide Vmw110.. Nucleic Acids Res 1991 Nov 25;19(22):6155-61.
          pubmed: 1659686doi: 10.1093/nar/19.22.6155google scholar: lookup
        4. Holden VR, Yalamanchili RR, Harty RN, O'Callaghan DJ. ICP22 homolog of equine herpesvirus 1: expression from early and late promoters.. J Virol 1992 Feb;66(2):664-73.
          pubmed: 1370553doi: 10.1128/JVI.66.2.664-673.1992google scholar: lookup
        5. Smith RH, Caughman GB, O'Callaghan DJ. Characterization of the regulatory functions of the equine herpesvirus 1 immediate-early gene product.. J Virol 1992 Feb;66(2):936-45.
          pubmed: 1309921doi: 10.1128/JVI.66.2.936-945.1992google scholar: lookup
        6. Stevenson D, Colman KL, Davison AJ. Characterization of the varicella-zoster virus gene 61 protein.. J Gen Virol 1992 Mar;73 ( Pt 3):521-30.
          pubmed: 1312115doi: 10.1099/0022-1317-73-3-521google scholar: lookup
        7. Wirth UV, Fraefel C, Vogt B, Vlcek C, Paces V, Schwyzer M. Immediate-early RNA 2.9 and early RNA 2.6 of bovine herpesvirus 1 are 3' coterminal and encode a putative zinc finger transactivator protein.. J Virol 1992 May;66(5):2763-72.
        8. Telford EA, Watson MS, McBride K, Davison AJ. The DNA sequence of equine herpesvirus-1.. Virology 1992 Jul;189(1):304-16.
          pubmed: 1318606doi: 10.1016/0042-6822(92)90706-ugoogle scholar: lookup
        9. Zhao Y, Holden VR, Harty RN, O'Callaghan DJ. Identification and transcriptional analyses of the UL3 and UL4 genes of equine herpesvirus 1, homologs of the ICP27 and glycoprotein K genes of herpes simplex virus.. J Virol 1992 Sep;66(9):5363-72.
        10. Flowers CC, O'Callaghan DJ. The equine herpesvirus type 1 (EHV-1) homolog of herpes simplex virus type 1 US9 and the nature of a major deletion within the unique short segment of the EHV-1 KyA strain genome.. Virology 1992 Sep;190(1):307-15.
          pubmed: 1326805doi: 10.1016/0042-6822(92)91217-igoogle scholar: lookup
        11. Moriuchi H, Moriuchi M, Smith HA, Straus SE, Cohen JI. Varicella-zoster virus open reading frame 61 protein is functionally homologous to herpes simplex virus type 1 ICP0.. J Virol 1992 Dec;66(12):7303-8.
        12. Smith RH, Zhao Y, O'Callaghan DJ. The equine herpesvirus 1 (EHV-1) UL3 gene, an ICP27 homolog, is necessary for full activation of gene expression directed by an EHV-1 late promoter.. J Virol 1993 Feb;67(2):1105-9.
        13. Harty RN, Holden VR, O'Callaghan DJ. Transcriptional and translational analyses of the UL2 gene of equine herpesvirus 1: a homolog of UL55 of herpes simplex virus type 1 that is maintained in the genome of defective interfering particles.. J Virol 1993 Apr;67(4):2255-65.
        14. Matsumura T, Smith RH, O'Callaghan DJ. DNA sequence and transcriptional analyses of the region of the equine herpesvirus type 1 Kentucky A strain genome encoding glycoprotein C.. Virology 1993 Apr;193(2):910-23.
          pubmed: 8384760doi: 10.1006/viro.1993.1200google scholar: lookup
        15. Moriuchi H, Moriuchi M, Straus SE, Cohen JI. Varicella-zoster virus (VZV) open reading frame 61 protein transactivates VZV gene promoters and enhances the infectivity of VZV DNA.. J Virol 1993 Jul;67(7):4290-5.
        16. Freemont PS. The RING finger. A novel protein sequence motif related to the zinc finger.. Ann N Y Acad Sci 1993 Jun 11;684:174-92.
        17. Senkevich TG, Koonin EV, Buller RM. A poxvirus protein with a RING zinc finger motif is of crucial importance for virulence.. Virology 1994 Jan;198(1):118-28.
          pubmed: 8259647doi: 10.1006/viro.1994.1014google scholar: lookup
        18. Purewal AS, Allsopp R, Riggio M, Telford EA, Azam S, Davison AJ, Edington N. Equid herpesviruses 1 and 4 encode functional homologs of the herpes simplex virus type 1 virion transactivator protein, VP16.. Virology 1994 Jan;198(1):385-9.
          pubmed: 8259676doi: 10.1006/viro.1994.1047google scholar: lookup
        19. Chen M, Harty RN, Zhao Y, Holden VR, O'Callaghan DJ. Expression of an equine herpesvirus 1 ICP22/ICP27 hybrid protein encoded by defective interfering particles associated with persistent infection.. J Virol 1996 Jan;70(1):313-20.
          pubmed: 8523542doi: 10.1128/JVI.70.1.313-320.1996google scholar: lookup
        20. Baxi MK, Efstathiou S, Lawrence G, Whalley JM, Slater JD, Field HJ. The detection of latency-associated transcripts of equine herpesvirus 1 in ganglionic neurons.. J Gen Virol 1995 Dec;76 ( Pt 12):3113-8.
          pubmed: 8847517doi: 10.1099/0022-1317-76-12-3113google scholar: lookup
        21. Matsumura T, O'Callaghan DJ, Kondo T, Kamada M. Lack of virulence of the murine fibroblast adapted strain, Kentucky A (KyA), of equine herpesvirus type 1 (EHV-1) in young horses.. Vet Microbiol 1996 Feb;48(3-4):353-65.
          pubmed: 9054131doi: 10.1016/0378-1135(09)59999-3google scholar: lookup
        22. Saurin AJ, Borden KL, Boddy MN, Freemont PS. Does this have a familiar RING?. Trends Biochem Sci 1996 Jun;21(6):208-14.
          pubmed: 8744354
        23. Davido DJ, Leib DA. Role of cis-acting sequences of the ICPO promoter of herpes simplex virus type 1 in viral pathogenesis, latency and reactivation.. J Gen Virol 1996 Aug;77 ( Pt 8):1853-63.
          pubmed: 8760437doi: 10.1099/0022-1317-77-8-1853google scholar: lookup
        24. Colle CF 3rd, Tarbet EB, Grafton WD, Jennings SR, O'Callaghan DJ. Equine herpesvirus-1 strain KyA, a candidate vaccine strain, reduces viral titers in mice challenged with a pathogenic strain, RacL.. Virus Res 1996 Aug;43(2):111-24.
          pubmed: 8864201doi: 10.1016/0168-1702(96)01324-xgoogle scholar: lookup
        25. Lees-Miller SP, Long MC, Kilvert MA, Lam V, Rice SA, Spencer CA. Attenuation of DNA-dependent protein kinase activity and its catalytic subunit by the herpes simplex virus type 1 transactivator ICP0.. J Virol 1996 Nov;70(11):7471-7.
        26. Kim SK, Holden VR, O'Callaghan DJ. The ICP22 protein of equine herpesvirus 1 cooperates with the IE protein to regulate viral gene expression.. J Virol 1997 Feb;71(2):1004-12.
        27. RANDALL CC, LAWSON LA. Adaptation of equine abortion virus to Earle's L cells in serum-free medium with plaque formation.. Proc Soc Exp Biol Med 1962 Jul;110:487-9.
          pubmed: 14490220doi: 10.3181/00379727-110-27558google scholar: lookup
        28. Everett RD, Barlow P, Milner A, Luisi B, Orr A, Hope G, Lyon D. A novel arrangement of zinc-binding residues and secondary structure in the C3HC4 motif of an alpha herpes virus protein family.. J Mol Biol 1993 Dec 20;234(4):1038-47.
          pubmed: 8263911doi: 10.1006/jmbi.1993.1657google scholar: lookup
        29. Fraefel C, Zeng J, Choffat Y, Engels M, Schwyzer M, Ackermann M. Identification and zinc dependence of the bovine herpesvirus 1 transactivator protein BICP0.. J Virol 1994 May;68(5):3154-62.
        30. Ciufo DM, Mullen MA, Hayward GS. Identification of a dimerization domain in the C-terminal segment of the IE110 transactivator protein from herpes simplex virus.. J Virol 1994 May;68(5):3267-82.
        31. Meredith M, Orr A, Everett R. Herpes simplex virus type 1 immediate-early protein Vmw110 binds strongly and specifically to a 135-kDa cellular protein.. Virology 1994 May 1;200(2):457-69.
          pubmed: 8178435doi: 10.1006/viro.1994.1209google scholar: lookup
        32. Watanabe S, Ono E, Shimizu Y, Kida H. Pseudorabies virus early protein 0 transactivates the viral gene promoters.. J Gen Virol 1995 Nov;76 ( Pt 11):2881-5.
          pubmed: 7595399doi: 10.1099/0022-1317-76-11-2881google scholar: lookup
        33. O'Callaghan DJ, Hyde JM, Gentry GA, Randall CC. Kinetics of viral deoxyribonucleic acid, protein, and infectious particle production and alterations in host macromolecular syntheses in equine abortion (herpes) virus-infected cells.. J Virol 1968 Aug;2(8):793-804.
          pubmed: 4302745doi: 10.1128/JVI.2.8.793-804.1968google scholar: lookup
        34. Sanger F, Nicklen S, Coulson AR. DNA sequencing with chain-terminating inhibitors.. Proc Natl Acad Sci U S A 1977 Dec;74(12):5463-7.
          pubmed: 271968doi: 10.1073/pnas.74.12.5463google scholar: lookup
        35. Caughman GB, Staczek J, O'Callaghan DJ. Equine herpesvirus type 1 infected cell polypeptides: evidence for immediate early/early/late regulation of viral gene expression.. Virology 1985 Aug;145(1):49-61.
          pubmed: 2990102doi: 10.1016/0042-6822(85)90200-4google scholar: lookup
        36. Stow ND, Stow EC. Isolation and characterization of a herpes simplex virus type 1 mutant containing a deletion within the gene encoding the immediate early polypeptide Vmw110.. J Gen Virol 1986 Dec;67 ( Pt 12):2571-85.
          pubmed: 3025339doi: 10.1099/0022-1317-67-12-2571google scholar: lookup
        37. Sacks WR, Schaffer PA. Deletion mutants in the gene encoding the herpes simplex virus type 1 immediate-early protein ICP0 exhibit impaired growth in cell culture.. J Virol 1987 Mar;61(3):829-39.
          pubmed: 3027408doi: 10.1128/JVI.61.3.829-839.1987google scholar: lookup
        38. Gray WL, Baumann RP, Robertson AT, Caughman GB, O'Callaghan DJ, Staczek J. Regulation of equine herpesvirus type 1 gene expression: characterization of immediate early, early, and late transcription.. Virology 1987 May;158(1):79-87.
          pubmed: 3033896doi: 10.1016/0042-6822(87)90240-6google scholar: lookup
        39. Baumann RP, Staczek J, O'Callaghan DJ. Equine herpesvirus type 1 defective-interfering (DI) particle DNA structure: the central region of the inverted repeat is deleted from DI DNA.. Virology 1987 Jul;159(1):137-46.
          pubmed: 3037774doi: 10.1016/0042-6822(87)90356-4google scholar: lookup
        40. Everett RD. A detailed mutational analysis of Vmw110, a trans-acting transcriptional activator encoded by herpes simplex virus type 1.. EMBO J 1987 Jul;6(7):2069-76.
        41. Gray WL, Baumann RP, Robertson AT, O'Callaghan DJ, Staczek J. Characterization and mapping of equine herpesvirus type 1 immediate early, early, and late transcripts.. Virus Res 1987 Sep;8(3):233-44.
          pubmed: 2825444doi: 10.1016/0168-1702(87)90018-9google scholar: lookup
        42. Grundy FJ, Baumann RP, O'Callaghan DJ. DNA sequence and comparative analyses of the equine herpesvirus type 1 immediate early gene.. Virology 1989 Sep;172(1):223-36.
          pubmed: 2549711doi: 10.1016/0042-6822(89)90124-4google scholar: lookup
        43. Clements GB, Stow ND. A herpes simplex virus type 1 mutant containing a deletion within immediate early gene 1 is latency-competent in mice.. J Gen Virol 1989 Sep;70 ( Pt 9):2501-6.
          pubmed: 2550578doi: 10.1099/0022-1317-70-9-2501google scholar: lookup
        44. Allen GP, Bryans JT. Molecular epizootiology, pathogenesis, and prophylaxis of equine herpesvirus-1 infections.. Prog Vet Microbiol Immunol 1986;2:78-144.
          pubmed: 2856183
        45. Yalamanchili RR, O'Callaghan DJ. Sequence and organization of the genomic termini of equine herpesvirus type 1.. Virus Res 1990 Feb;15(2):149-61.
          pubmed: 2157316doi: 10.1016/0168-1702(90)90005-vgoogle scholar: lookup
        46. Chen JX, Zhu XX, Silverstein S. Mutational analysis of the sequence encoding ICP0 from herpes simplex virus type 1.. Virology 1991 Jan;180(1):207-20.
          pubmed: 1845823doi: 10.1016/0042-6822(91)90025-7google scholar: lookup
        47. Koerner TJ, Hill JE, Myers AM, Tzagoloff A. High-expression vectors with multiple cloning sites for construction of trpE fusion genes: pATH vectors.. Methods Enzymol 1991;194:477-90.
          pubmed: 2005804doi: 10.1016/0076-6879(91)94036-cgoogle scholar: lookup
        48. Harty RN, O'Callaghan DJ. An early gene maps within and is 3' coterminal with the immediate-early gene of equine herpesvirus 1.. J Virol 1991 Jul;65(7):3829-38.
        49. Yalamanchili RR, Raengsakulrach B, O'Callaghan DJ. Equine herpesvirus 1 sequence near the left terminus codes for two open reading frames.. Virus Res 1991 Mar;18(2-3):109-16.
          pubmed: 1645901doi: 10.1016/0168-1702(91)90012-kgoogle scholar: lookup
        50. Cai W, Schaffer PA. A cellular function can enhance gene expression and plating efficiency of a mutant defective in the gene for ICP0, a transactivating protein of herpes simplex virus type 1.. J Virol 1991 Aug;65(8):4078-90.
        51. Cheung AK. Cloning of the latency gene and the early protein 0 gene of pseudorabies virus.. J Virol 1991 Oct;65(10):5260-71.
        52. Smith RH, Zhao Y, O'Callaghan DJ. The equine herpesvirus type 1 immediate-early gene product contains an acidic transcriptional activation domain.. Virology 1994 Aug 1;202(2):760-70.
          pubmed: 8030239doi: 10.1006/viro.1994.1398google scholar: lookup
        53. Ralph WM Jr, Cabatingan MS, Schaffer PA. Induction of herpes simplex virus type 1 immediate-early gene expression by a cellular activity expressed in Vero and NB41A3 cells after growth arrest-release.. J Virol 1994 Nov;68(11):6871-82.
        54. Stevenson D, Colman KL, Davison AJ. Delineation of a sequence required for nuclear localization of the protein encoded by varicella-zoster virus gene 61.. J Gen Virol 1994 Nov;75 ( Pt 11):3229-33.
          pubmed: 7964633doi: 10.1099/0022-1317-75-11-3229google scholar: lookup
        55. Yao F, Schaffer PA. Physical interaction between the herpes simplex virus type 1 immediate-early regulatory proteins ICP0 and ICP4.. J Virol 1994 Dec;68(12):8158-68.
        56. Moriuchi H, Moriuchi M, Cohen JI. The RING finger domain of the varicella-zoster virus open reading frame 61 protein is required for its transregulatory functions.. Virology 1994 Nov 15;205(1):238-46.
          pubmed: 7975220doi: 10.1006/viro.1994.1639google scholar: lookup
        57. Zhao Y, Holden VR, Smith RH, O'Callaghan DJ. Regulatory function of the equine herpesvirus 1 ICP27 gene product.. J Virol 1995 May;69(5):2786-93.
        58. Smith RH, Holden VR, O'Callaghan DJ. Nuclear localization and transcriptional activation activities of truncated versions of the immediate-early gene product of equine herpesvirus 1.. J Virol 1995 Jun;69(6):3857-62.
        59. Meredith M, Orr A, Elliott M, Everett R. Separation of sequence requirements for HSV-1 Vmw110 multimerisation and interaction with a 135-kDa cellular protein.. Virology 1995 May 10;209(1):174-87.
          pubmed: 7747467doi: 10.1006/viro.1995.1241google scholar: lookup
        60. Crabb BS, Studdert MJ. Equine herpesviruses 4 (equine rhinopneumonitis virus) and 1 (equine abortion virus).. Adv Virus Res 1995;45:153-90.
          pubmed: 7793324doi: 10.1016/s0065-3527(08)60060-3google scholar: lookup
        61. Colle CF 3rd, O'Callaghan DJ. Transcriptional analyses of the unique short segment of EHV-1 strain Kentucky A.. Virus Genes 1995 Feb;9(3):257-68.
          pubmed: 7597804doi: 10.1007/BF01702881google scholar: lookup
        62. Holden VR, Zhao Y, Thompson Y, Caughman GB, Smith RH, O'Callaghan DJ. Characterization of the regulatory function of the ICP22 protein of equine herpesvirus type 1.. Virology 1995 Jul 10;210(2):273-82.
          pubmed: 7618267doi: 10.1006/viro.1995.1344google scholar: lookup
        63. Yao F, Schaffer PA. An activity specified by the osteosarcoma line U2OS can substitute functionally for ICP0, a major regulatory protein of herpes simplex virus type 1.. J Virol 1995 Oct;69(10):6249-58.
        64. Everett R, Orr A, Elliott M. The equine herpesvirus 1 gene 63 RING finger protein partially complements Vmw110, its herpes simplex virus type 1 counterpart.. J Gen Virol 1995 Sep;76 ( Pt 9):2369-74.
          pubmed: 7561779doi: 10.1099/0022-1317-76-9-2369google scholar: lookup
        65. Kim SK, Smith RH, O'Callaghan DJ. Characterization of DNA binding properties of the immediate-early gene product of equine herpesvirus type 1.. Virology 1995 Oct 20;213(1):46-56.
          pubmed: 7483278doi: 10.1006/viro.1995.1545google scholar: lookup

        Citations

        This article has been cited 29 times.
        1. Oladunni FS, Horohov DW, Chambers TM. EHV-1: A Constant Threat to the Horse Industry.. Front Microbiol 2019;10:2668.
          doi: 10.3389/fmicb.2019.02668pubmed: 31849857google scholar: lookup
        2. Bryant NA, Wilkie GS, Russell CA, Compston L, Grafham D, Clissold L, McLay K, Medcalf L, Newton R, Davison AJ, Elton DM. Genetic diversity of equine herpesvirus 1 isolated from neurological, abortigenic and respiratory disease outbreaks.. Transbound Emerg Dis 2018 Jun;65(3):817-832.
          doi: 10.1111/tbed.12809pubmed: 29423949google scholar: lookup
        3. Shakya AK, O'Callaghan DJ, Kim SK. Comparative Genomic Sequencing and Pathogenic Properties of Equine Herpesvirus 1 KyA and RacL11.. Front Vet Sci 2017;4:211.
          doi: 10.3389/fvets.2017.00211pubmed: 29312962google scholar: lookup
        4. Kim SK, Shakya AK, O'Callaghan DJ. Immunization with Attenuated Equine Herpesvirus 1 Strain KyA Induces Innate Immune Responses That Protect Mice from Lethal Challenge.. J Virol 2016 Sep 15;90(18):8090-104.
          doi: 10.1128/JVI.00986-16pubmed: 27356904google scholar: lookup
        5. Kim SK, Shakya AK, O'Callaghan DJ. Full trans-activation mediated by the immediate-early protein of equine herpesvirus 1 requires a consensus TATA box, but not its cognate binding sequence.. Virus Res 2016 Jan 4;211:222-32.
        6. Zhang Y, Charvat RA, Kim SK, O'Callaghan DJ. The EHV-1 UL4 protein that tempers viral gene expression interacts with cellular transcription factors.. Virology 2014 Jan 20;449:25-34.
          doi: 10.1016/j.virol.2013.11.005pubmed: 24418534google scholar: lookup
        7. Zhang MJ, Cheng RL, Lou YH, Ye WL, Zhang T, Fan XY, Fan HW, Zhang CX. Disruption of Bombyx mori nucleopolyhedrovirus ORF71 (Bm71) results in inefficient bí·­ virus production and decreased virulence in host larvae.. Virus Genes 2012 Aug;45(1):161-8.
          doi: 10.1007/s11262-012-0757-2pubmed: 22585339google scholar: lookup
        8. Kim S, Dai G, O'Callaghan DJ, Kim SK. Characterization of cis-acting elements required for autorepression of the equine herpesvirus 1 IE gene.. Virus Res 2012 Apr;165(1):52-60.
        9. Jones C. Regulation of Innate Immune Responses by Bovine Herpesvirus 1 and Infected Cell Protein 0 (bICP0).. Viruses 2009 Sep;1(2):255-75.
          doi: 10.3390/v1020255pubmed: 21994549google scholar: lookup
        10. Ahn BC, Kim S, Zhang Y, Charvat RA, O'Callaghan DJ. The early UL3 gene of equine herpesvirus-1 encodes a tegument protein not essential for replication or virulence in the mouse.. Virology 2011 Nov 10;420(1):20-31.
          doi: 10.1016/j.virol.2011.08.016pubmed: 21917286google scholar: lookup
        11. Kim SK, Kim S, Dai G, Zhang Y, Ahn BC, O'Callaghan DJ. Identification of functional domains of the IR2 protein of equine herpesvirus 1 required for inhibition of viral gene expression and replication.. Virology 2011 Sep 1;417(2):430-42.
          doi: 10.1016/j.virol.2011.06.023pubmed: 21794889google scholar: lookup
        12. da Silva LF, Gaudreault N, Jones C. Cytoplasmic localized infected cell protein 0 (bICP0) encoded by bovine herpesvirus 1 inhibits β interferon promoter activity and reduces IRF3 (interferon response factor 3) protein levels.. Virus Res 2011 Sep;160(1-2):143-9.
        13. Charvat RA, Breitenbach JE, Ahn B, Zhang Y, O'Callaghan DJ. The UL4 protein of equine herpesvirus 1 is not essential for replication or pathogenesis and inhibits gene expression controlled by viral and heterologous promoters.. Virology 2011 Apr 10;412(2):366-77.
          doi: 10.1016/j.virol.2011.01.025pubmed: 21324502google scholar: lookup
        14. Ahn B, Zhang Y, Osterrieder N, O'Callaghan DJ. Properties of an equine herpesvirus 1 mutant devoid of the internal inverted repeat sequence of the genomic short region.. Virology 2011 Feb 20;410(2):327-35.
          doi: 10.1016/j.virol.2010.11.020pubmed: 21176938google scholar: lookup
        15. Ahn BC, Zhang Y, O'Callaghan DJ. The equine herpesvirus-1 (EHV-1) IR3 transcript downregulates expression of the IE gene and the absence of IR3 gene expression alters EHV-1 biological properties and virulence.. Virology 2010 Jul 5;402(2):327-37.
          doi: 10.1016/j.virol.2010.03.051pubmed: 20417949google scholar: lookup
        16. Everett RD, Boutell C, McNair C, Grant L, Orr A. Comparison of the biological and biochemical activities of several members of the alphaherpesvirus ICP0 family of proteins.. J Virol 2010 Apr;84(7):3476-87.
          doi: 10.1128/JVI.02544-09pubmed: 20106921google scholar: lookup
        17. Saira K, Zhou Y, Jones C. The infected cell protein 0 encoded by bovine herpesvirus 1 (bICP0) associates with interferon regulatory factor 7 and consequently inhibits beta interferon promoter activity.. J Virol 2009 Apr;83(8):3977-81.
          doi: 10.1128/JVI.02400-08pubmed: 19176627google scholar: lookup
        18. Breitenbach JE, Ebner PD, O'Callaghan DJ. The IR4 auxiliary regulatory protein expands the in vitro host range of equine herpesvirus 1 and is essential for pathogenesis in the murine model.. Virology 2009 Jan 20;383(2):188-94.
          doi: 10.1016/j.virol.2008.10.017pubmed: 19012943google scholar: lookup
        19. Saira K, Chowdhury S, Gaudreault N, da Silva L, Henderson G, Doster A, Jones C. The zinc RING finger of bovine herpesvirus 1-encoded bICP0 protein is crucial for viral replication and virulence.. J Virol 2008 Dec;82(24):12060-8.
          doi: 10.1128/JVI.01348-08pubmed: 18842710google scholar: lookup
        20. Ahn BC, Breitenbach JE, Kim SK, O'Callaghan DJ. The equine herpesvirus-1 IR3 gene that lies antisense to the sole immediate-early (IE) gene is trans-activated by the IE protein, and is poorly expressed to a protein.. Virology 2007 Jun 20;363(1):15-25.
          doi: 10.1016/j.virol.2007.01.024pubmed: 17306852google scholar: lookup
        21. Kim SK, Ahn BC, Albrecht RA, O'Callaghan DJ. The unique IR2 protein of equine herpesvirus 1 negatively regulates viral gene expression.. J Virol 2006 May;80(10):5041-9.
        22. von Einem J, Schumacher D, O'Callaghan DJ, Osterrieder N. The alpha-TIF (VP16) homologue (ETIF) of equine herpesvirus 1 is essential for secondary envelopment and virus egress.. J Virol 2006 Mar;80(6):2609-20.
        23. Buczynski KA, Kim SK, O'Callaghan DJ. Initial characterization of 17 viruses harboring mutant forms of the immediate-early gene of equine herpesvirus 1.. Virus Genes 2005 Oct;31(2):229-39.
          doi: 10.1007/s11262-005-1801-2pubmed: 16025249google scholar: lookup
        24. Kim SK, Albrecht RA, O'Callaghan DJ. A negative regulatory element (base pairs -204 to -177) of the EICP0 promoter of equine herpesvirus 1 abolishes the EICP0 protein's trans-activation of its own promoter.. J Virol 2004 Nov;78(21):11696-706.
        25. Kim SK, Jang HK, Albrecht RA, Derbigny WA, Zhang Y, O'Callaghan DJ. Interaction of the equine herpesvirus 1 EICP0 protein with the immediate-early (IE) protein, TFIIB, and TBP may mediate the antagonism between the IE and EICP0 proteins.. J Virol 2003 Feb;77(4):2675-85.
        26. Zhang Y, Jones C. The bovine herpesvirus 1 immediate-early protein (bICP0) associates with histone deacetylase 1 to activate transcription.. J Virol 2001 Oct;75(20):9571-8.
        27. Smith PM, Zhang Y, Grafton WD, Jennings SR, O'Callaghan DJ. Severe murine lung immunopathology elicited by the pathogenic equine herpesvirus 1 strain RacL11 correlates with early production of macrophage inflammatory proteins 1alpha, 1beta, and 2 and tumor necrosis factor alpha.. J Virol 2000 Nov;74(21):10034-40.
        28. Derbigny WA, Kim SK, Caughman GB, O'Callaghan DJ. The EICP22 protein of equine herpesvirus 1 physically interacts with the immediate-early protein and with itself to form dimers and higher-order complexes.. J Virol 2000 Feb;74(3):1425-35.
        29. Bowles DE, Kim SK, O'Callaghan DJ. Characterization of the trans-activation properties of equine herpesvirus 1 EICP0 protein.. J Virol 2000 Feb;74(3):1200-8.