Proteolytic processing of the replicase ORF1a protein of equine arteritis virus.
- Journal Article
Summary
The research examines the proteolytic processing of the equine arteritis virus (EAV) using specific antisera. This process was studied in infected cells through methods such as Western blot and immunoprecipitation techniques. Findings discovered that the ORF1a protein underwent at least five proteolytic cleavages, each resulting in proteins of various sizes.
Research Methodologies
For this research, scientists used several methods:
- Raised specific antisera in rabbits using six synthetic peptides and a bacterial fusion protein as antigens to study the ORF1a protein of the equine arteritis virus (EAV).
- The processing of the EAV ORF1a protein in infected cells was analyzed with Western blot (immunoblot) and immunoprecipitation techniques. Both methods are experimental procedures used to detect specific proteins based on their ability to bind to specific antibodies.
- Additional information was gleaned from the transient expression of ORF1a cDNA constructs. This involves introducing the ORF1a gene into a host organism and studying its expression or functionality within that organism.
Findings
The research led to several key findings:
- The 187-kDa ORF1a protein underwent at least five proteolytic cleavages. Proteolytic cleavage refers to the process where proteins are broken down to smaller pieces.
- The cleavage products, named nonstructural proteins (nsps) 1 through 6, had weights approximately 29, 61, 22, 31, 41, and 3 kDa. These various sized proteins would have different functional roles in the replication and infection process of the virus.
- Pulse-chase experiments showed the most rapid processing steps were at the nsp1/2 and nsp2/3 junctions. Pulse-chase experiments are a method used to study the rate of protein synthesis and degradation.
- The other processing steps were performed by the EAV serine protease in nsp4 and by a third unidentified protease. Proteases are enzymes that break down proteins.
Implication of Findings
These findings provide important insights into the proteolytic processing of the EAV ORF1a protein. Understanding these processes could be key to developing treatments or vaccines for diseases caused by the equine arteritis virus.
Cite This Article
Publication
Researcher Affiliations
- Department of Virology, Faculty of Medicine, Leiden University, The Netherlands.
MeSH Terms
- Amino Acid Sequence
- Equartevirus / enzymology
- Genes, Viral
- Molecular Sequence Data
- Open Reading Frames
- Peptides / chemistry
- Peptides / immunology
- Precipitin Tests
- Protein Processing, Post-Translational
- RNA-Dependent RNA Polymerase / metabolism
- Solubility
- Time Factors
- Viral Proteins / chemistry
- Viral Proteins / immunology
- Viral Proteins / metabolism
- Viral Structural Proteins / genetics
References
- J Gen Virol. 1988 Jul;69 ( Pt 7):1627-36
- Cornell Vet. 1957 Jan;47(1):3-41
- Virology. 1988 Sep;166(1):265-70
- Gene. 1988 Jul 15;67(1):31-40
- Proc Natl Acad Sci U S A. 1988 Nov;85(21):7872-6
- FEBS Lett. 1989 Jan 30;243(2):103-14
- Nucleic Acids Res. 1989 Jun 26;17(12):4847-61
- Proc Natl Acad Sci U S A. 1989 Aug;86(16):6126-30
- Nucleic Acids Res. 1990 Apr 11;18(7):1825-32
- Nucleic Acids Res. 1990 Jun 11;18(11):3241-7
- EMBO J. 1990 Aug;9(8):2631-8
- Virology. 1990 Aug;177(2):634-45
- Virology. 1990 Aug;177(2):646-56
- Nucleic Acids Res. 1990 Aug 11;18(15):4535-42
- Virology. 1991 Feb;180(2):567-82
- Nature. 1970 Aug 15;227(5259):680-5
- Methods Enzymol. 1980;70(A):159-65
- J Mol Biol. 1982 May 5;157(1):105-32
- Zentralbl Veterinarmed B. 1983 May;30(4):297-304
- Nucleic Acids Res. 1984 Jan 11;12(1 Pt 1):387-95
- Proc Natl Acad Sci U S A. 1986 Nov;83(21):8122-6
- J Gen Virol. 1987 Jan;68 ( Pt 1):57-77
- Methods Enzymol. 1987;154:367-82
- J Virol. 1991 Mar;65(3):1496-506
- J Virol. 1991 Jun;65(6):2910-20
- J Virol. 1991 Jun;65(6):3076-82
- Gene. 1991 Dec 15;108(2):201-9
- Adv Virus Res. 1992;41:99-192
- Virology. 1992 Jul;189(1):274-84
- J Virol. 1992 Nov;66(11):6294-303
- J Virol. 1992 Nov;66(11):6322-9
- J Virol. 1992 Dec;66(12):7040-8
- Virology. 1992 Dec;191(2):687-97
- J Virol. 1993 Apr;67(4):1916-26
- J Gen Virol. 1993 Apr;74 ( Pt 4):643-59
- Virology. 1993 Jun;194(2):585-96
- Virology. 1993 Jan;192(1):62-72
- Virology. 1993 Aug;195(2):680-91
- J Virol. 1993 Oct;67(10):6056-63
- J Gen Virol. 1993 Nov;74 ( Pt 11):2305-16
- Virology. 1994 Feb;198(2):736-40
- Microbiol Rev. 1993 Dec;57(4):781-822
- J Virol. 1994 Mar;68(3):1874-85
- J Virol. 1988 Aug;62(8):2636-43
Citations
This article has been cited 87 times.- Lan X, Liang F, Li G, Ye Y, Li F, Lv C, Liu K, Yang Z, Sun R, Zhang K, Wang L, Li H, Zhao M, Huang L. Research progress on NSP4 protein of porcine reproductive and respiratory syndrome virus. Vet Res Commun 2026 Feb 9;50(2):152.
- Chen M, Zhao Y, An H, Han Q, Cui C, Peng J, Xiao Y, Wang G, Shang Y. Cytoplasmic translocation of tripartite motif-containing 28 is critical for PRRSV-induced autophagy through promoting Vps34-Beclin1 complex formation. J Virol 2025 Oct 23;99(10):e0113325.
- Wang X, Chen Y, Qi C, Li F, Zhang Y, Zhou J, Wu H, Zhang T, Qi A, Ouyang H, Xie Z, Pang D. Mechanism, structural and functional insights into nidovirus-induced double-membrane vesicles. Front Immunol 2024;15:1340332.
- Liao Y, Wang H, Liao H, Sun Y, Tan L, Song C, Qiu X, Ding C. Classification, replication, and transcription of Nidovirales. Front Microbiol 2023;14:1291761.
- Hsu CY, Jang Y, Huang WR, Wang CY, Wen HW, Tsai PC, Yang CY, Munir M, Liu HJ. Development of Polycistronic Baculovirus Surface Display Vectors to Simultaneously Express Viral Proteins of Porcine Reproductive and Respiratory Syndrome and Analysis of Their Immunogenicity in Swine. Vaccines (Basel) 2023 Oct 31;11(11).
- Zhang L, Pan Y, Xu Y, Zhang W, Ma W, Ibrahim YM, Werid GM, Zhang H, Xia C, Wei P, Chen H, Wang Y. Paraoxonase-1 Facilitates PRRSV Replication by Interacting with Viral Nonstructural Protein-9 and Inhibiting Type I Interferon Pathway. Viruses 2022 May 31;14(6).
- Cook GM, Brown K, Shang P, Li Y, Soday L, Dinan AM, Tumescheit C, Mockett APA, Fang Y, Firth AE, Brierley I. Ribosome profiling of porcine reproductive and respiratory syndrome virus reveals novel features of viral gene expression. Elife 2022 Feb 28;11.
- Xiong J, Cui X, Zhao K, Wang Q, Huang X, Li D, Yu F, Yang Y, Liu D, Tian Z, Cai X, An T. A Novel Motif in the 3'-UTR of PRRSV-2 Is Critical for Viral Multiplication and Contributes to Enhanced Replication Ability of Highly Pathogenic or L1 PRRSV. Viruses 2022 Jan 18;14(2).
- Wen X, Ge X, Zhou L, Zhang Y, Guo X, Yang H. PRRSV Promotes MARC-145 Cells Entry Into S Phase of the Cell Cycle to Facilitate Viral Replication via Degradation of p21 by nsp11. Front Vet Sci 2021;8:642095.
- Patel A, Treffers EE, Meier M, Patel TR, Stetefeld J, Snijder EJ, Mark BL. Molecular characterization of the RNA-protein complex directing -2/-1 programmed ribosomal frameshifting during arterivirus replicase expression. J Biol Chem 2020 Dec 25;295(52):17904-17921.
- Ogando NS, Dalebout TJ, Zevenhoven-Dobbe JC, Limpens RWAL, van der Meer Y, Caly L, Druce J, de Vries JJC, Kikkert M, Bárcena M, Sidorov I, Snijder EJ. SARS-coronavirus-2 replication in Vero E6 cells: replication kinetics, rapid adaptation and cytopathology. J Gen Virol 2020 Sep;101(9):925-940.
- Jiang Y, Li G, Yu L, Li L, Zhang Y, Zhou Y, Tong W, Liu C, Gao F, Tong G. Genetic Diversity of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) From 1996 to 2017 in China. Front Microbiol 2020;11:618.
- de Vries AAF, Horzinek MC, Rottier PJM, de Groot RJ. The Genome Organization of the Nidovirales: Similarities and Differences between Arteri-, Toro-, and Coronaviruses. Semin Virol 1997 Feb;8(1):33-47.
- Zhou S, Ge X, Kong C, Liu T, Liu A, Gao P, Song J, Zhou L, Guo X, Han J, Yang H. Characterizing the PRRSV nsp2 Deubiquitinase Reveals Dispensability of Cis-Activity for Replication and a Link of nsp2 to Inflammation Induction. Viruses 2019 Sep 26;11(10).
- de Wilde AH, Boomaars-van der Zanden AL, de Jong AWM, Bárcena M, Snijder EJ, Posthuma CC. Adaptive Mutations in Replicase Transmembrane Subunits Can Counteract Inhibition of Equine Arteritis Virus RNA Synthesis by Cyclophilin Inhibitors. J Virol 2019 Sep 15;93(18).
- Chen J, Wang D, Sun Z, Gao L, Zhu X, Guo J, Xu S, Fang L, Li K, Xiao S. Arterivirus nsp4 Antagonizes Interferon Beta Production by Proteolytically Cleaving NEMO at Multiple Sites. J Virol 2019 Jun 15;93(12).
- Liu Y, Hu Y, Chai Y, Liu L, Song J, Zhou S, Su J, Zhou L, Ge X, Guo X, Han J, Yang H. Identification of Nonstructural Protein 8 as the N-Terminus of the RNA-Dependent RNA Polymerase of Porcine Reproductive and Respiratory Syndrome Virus. Virol Sin 2018 Oct;33(5):429-439.
- Wang C, Zeng N, Liu S, Miao Q, Zhou L, Ge X, Han J, Guo X, Yang H. Interaction of porcine reproductive and respiratory syndrome virus proteins with SUMO-conjugating enzyme reveals the SUMOylation of nucleocapsid protein. PLoS One 2017;12(12):e0189191.
- Leng C, Zhang W, Zhang H, Kan Y, Yao L, Zhai H, Li M, Li Z, Liu C, An T, Peng J, Wang Q, Leng Y, Cai X, Tian Z, Tong G. ORF1a of highly pathogenic PRRS attenuated vaccine virus plays a key role in neutralizing antibody induction in piglets and virus neutralization in vitro. Virol J 2017 Aug 22;14(1):159.
- Wang H, Liu R, Zhang W, Sun L, Ning Z, Ji F, Cui J, Zhang G. Identification of epitopes on nonstructural protein 7 of porcine reproductive and respiratory syndrome virus recognized by monoclonal antibodies using phage-display technology. Virus Genes 2017 Aug;53(4):623-635.
- van der Hoeven B, Oudshoorn D, Koster AJ, Snijder EJ, Kikkert M, Bárcena M. Biogenesis and architecture of arterivirus replication organelles. Virus Res 2016 Jul 15;220:70-90.
- Steinbach F, Westcott DG, McGowan SL, Grierson SS, Frossard JP, Choudhury B. Re-emergence of a genetic outlier strain of equine arteritis virus: Impact on phylogeny. Virus Res 2015 Apr 16;202:144-50.
- Han M, Yoo D. Modulation of innate immune signaling by nonstructural protein 1 (nsp1) in the family Arteriviridae. Virus Res 2014 Dec 19;194:100-9.
- Li Y, Zhou L, Zhang J, Ge X, Zhou R, Zheng H, Geng G, Guo X, Yang H. Nsp9 and Nsp10 contribute to the fatal virulence of highly pathogenic porcine reproductive and respiratory syndrome virus emerging in China. PLoS Pathog 2014 Jul;10(7):e1004216.
- Go YY, Li Y, Chen Z, Han M, Yoo D, Fang Y, Balasuriya UB. Equine arteritis virus does not induce interferon production in equine endothelial cells: identification of nonstructural protein 1 as a main interferon antagonist. Biomed Res Int 2014;2014:420658.
- Wang L, Zhang K, Lin H, Li W, Wen J, Zhang J, Zhang Y, Li X, Zhong F. Preparation of North American type II PRRSV infectious clone expressing green fluorescent protein. Biomed Res Int 2014;2014:368581.
- Li Y, Treffers EE, Napthine S, Tas A, Zhu L, Sun Z, Bell S, Mark BL, van Veelen PA, van Hemert MJ, Firth AE, Brierley I, Snijder EJ, Fang Y. Transactivation of programmed ribosomal frameshifting by a viral protein. Proc Natl Acad Sci U S A 2014 May 27;111(21):E2172-81.
- Zhou L, Yang X, Tian Y, Yin S, Geng G, Ge X, Guo X, Yang H. Genetic diversity analysis of genotype 2 porcine reproductive and respiratory syndrome viruses emerging in recent years in China. Biomed Res Int 2014;2014:748068.
- Yun SI, Lee YM. Overview: Replication of porcine reproductive and respiratory syndrome virus. J Microbiol 2013 Dec;51(6):711-23.
- Balasuriya UB, Go YY, MacLachlan NJ. Equine arteritis virus. Vet Microbiol 2013 Nov 29;167(1-2):93-122.
- de Wilde AH, Raj VS, Oudshoorn D, Bestebroer TM, van Nieuwkoop S, Limpens RWAL, Posthuma CC, van der Meer Y, Bárcena M, Haagmans BL, Snijder EJ, van den Hoogen BG. MERS-coronavirus replication induces severe in vitro cytopathology and is strongly inhibited by cyclosporin A or interferon-α treatment. J Gen Virol 2013 Aug;94(Pt 8):1749-1760.
- Fang Y, Treffers EE, Li Y, Tas A, Sun Z, van der Meer Y, de Ru AH, van Veelen PA, Atkins JF, Snijder EJ, Firth AE. Efficient -2 frameshifting by mammalian ribosomes to synthesize an additional arterivirus protein. Proc Natl Acad Sci U S A 2012 Oct 23;109(43):E2920-8.
- Fang Y, Fang L, Wang Y, Lei Y, Luo R, Wang D, Chen H, Xiao S. Porcine reproductive and respiratory syndrome virus nonstructural protein 2 contributes to NF-κB activation. Virol J 2012 Apr 30;9:83.
- Tian D, Wei Z, Zevenhoven-Dobbe JC, Liu R, Tong G, Snijder EJ, Yuan S. Arterivirus minor envelope proteins are a major determinant of viral tropism in cell culture. J Virol 2012 Apr;86(7):3701-12.
- Sun Z, Li Y, Ransburgh R, Snijder EJ, Fang Y. Nonstructural protein 2 of porcine reproductive and respiratory syndrome virus inhibits the antiviral function of interferon-stimulated gene 15. J Virol 2012 Apr;86(7):3839-50.
- Go YY, Snijder EJ, Timoney PJ, Balasuriya UB. Characterization of equine humoral antibody response to the nonstructural proteins of equine arteritis virus. Clin Vaccine Immunol 2011 Feb;18(2):268-79.
- Fang Y, Snijder EJ. The PRRSV replicase: exploring the multifunctionality of an intriguing set of nonstructural proteins. Virus Res 2010 Dec;154(1-2):61-76.
- Faaberg KS, Kehrli ME Jr, Lager KM, Guo B, Han J. In vivo growth of porcine reproductive and respiratory syndrome virus engineered nsp2 deletion mutants. Virus Res 2010 Dec;154(1-2):77-85.
- Yoo D, Song C, Sun Y, Du Y, Kim O, Liu HC. Modulation of host cell responses and evasion strategies for porcine reproductive and respiratory syndrome virus. Virus Res 2010 Dec;154(1-2):48-60.
- Song J, Shen D, Cui J, Zhao B. Accelerated evolution of PRRSV during recent outbreaks in China. Virus Genes 2010 Oct;41(2):241-5.
- Sun Z, Chen Z, Lawson SR, Fang Y. The cysteine protease domain of porcine reproductive and respiratory syndrome virus nonstructural protein 2 possesses deubiquitinating and interferon antagonism functions. J Virol 2010 Aug;84(15):7832-46.
- Kim O, Sun Y, Lai FW, Song C, Yoo D. Modulation of type I interferon induction by porcine reproductive and respiratory syndrome virus and degradation of CREB-binding protein by non-structural protein 1 in MARC-145 and HeLa cells. Virology 2010 Jul 5;402(2):315-26.
- Han J, Rutherford MS, Faaberg KS. The porcine reproductive and respiratory syndrome virus nsp2 cysteine protease domain possesses both trans- and cis-cleavage activities. J Virol 2009 Sep;83(18):9449-63.
- Zhou L, Zhang J, Zeng J, Yin S, Li Y, Zheng L, Guo X, Ge X, Yang H. The 30-amino-acid deletion in the Nsp2 of highly pathogenic porcine reproductive and respiratory syndrome virus emerging in China is not related to its virulence. J Virol 2009 May;83(10):5156-67.
- Zevenhoven-Dobbe JC, Wassenaar AL, van der Meer Y, Snijder EJ. Production of monospecific rabbit antisera recognizing nidovirus proteins. Methods Mol Biol 2008;454:205-26.
- Posthuma CC, Pedersen KW, Lu Z, Joosten RG, Roos N, Zevenhoven-Dobbe JC, Snijder EJ. Formation of the arterivirus replication/transcription complex: a key role for nonstructural protein 3 in the remodeling of intracellular membranes. J Virol 2008 May;82(9):4480-91.
- Frias-Staheli N, Giannakopoulos NV, Kikkert M, Taylor SL, Bridgen A, Paragas J, Richt JA, Rowland RR, Schmaljohn CS, Lenschow DJ, Snijder EJ, García-Sastre A, Virgin HW 4th. Ovarian tumor domain-containing viral proteases evade ubiquitin- and ISG15-dependent innate immune responses. Cell Host Microbe 2007 Dec 13;2(6):404-16.
- Tijms MA, Nedialkova DD, Zevenhoven-Dobbe JC, Gorbalenya AE, Snijder EJ. Arterivirus subgenomic mRNA synthesis and virion biogenesis depend on the multifunctional nsp1 autoprotease. J Virol 2007 Oct;81(19):10496-505.
- Fang Y, Rowland RR, Roof M, Lunney JK, Christopher-Hennings J, Nelson EA. A full-length cDNA infectious clone of North American type 1 porcine reproductive and respiratory syndrome virus: expression of green fluorescent protein in the Nsp2 region. J Virol 2006 Dec;80(23):11447-55.
- Snijder EJ, van der Meer Y, Zevenhoven-Dobbe J, Onderwater JJ, van der Meulen J, Koerten HK, Mommaas AM. Ultrastructure and origin of membrane vesicles associated with the severe acute respiratory syndrome coronavirus replication complex. J Virol 2006 Jun;80(12):5927-40.
- Smits SL, Snijder EJ, de Groot RJ. Characterization of a torovirus main proteinase. J Virol 2006 Apr;80(8):4157-67.
- van Aken D, Snijder EJ, Gorbalenya AE. Mutagenesis analysis of the nsp4 main proteinase reveals determinants of arterivirus replicase polyprotein autoprocessing. J Virol 2006 Apr;80(7):3428-37.
- van Aken D, Benckhuijsen WE, Drijfhout JW, Wassenaar AL, Gorbalenya AE, Snijder EJ. Expression, purification, and in vitro activity of an arterivirus main proteinase. Virus Res 2006 Sep;120(1-2):97-106.
- van den Born E, Posthuma CC, Gultyaev AP, Snijder EJ. Discontinuous subgenomic RNA synthesis in arteriviruses is guided by an RNA hairpin structure located in the genomic leader region. J Virol 2005 May;79(10):6312-24.
- Ivanov KA, Thiel V, Dobbe JC, van der Meer Y, Snijder EJ, Ziebuhr J. Multiple enzymatic activities associated with severe acute respiratory syndrome coronavirus helicase. J Virol 2004 Jun;78(11):5619-32.
- Ropp SL, Wees CE, Fang Y, Nelson EA, Rossow KD, Bien M, Arndt B, Preszler S, Steen P, Christopher-Hennings J, Collins JE, Benfield DA, Faaberg KS. Characterization of emerging European-like porcine reproductive and respiratory syndrome virus isolates in the United States. J Virol 2004 Apr;78(7):3684-703.
- Wieringa R, De Vries AA, Post SM, Rottier PJ. Intra- and intermolecular disulfide bonds of the GP2b glycoprotein of equine arteritis virus: relevance for virus assembly and infectivity. J Virol 2003 Dec;77(24):12996-3004.
- Bautista EM, Faaberg KS, Mickelson D, McGruder ED. Functional properties of the predicted helicase of porcine reproductive and respiratory syndrome virus. Virology 2002 Jul 5;298(2):258-70.
- Tijms MA, van Dinten LC, Gorbalenya AE, Snijder EJ. A zinc finger-containing papain-like protease couples subgenomic mRNA synthesis to genome translation in a positive-stranded RNA virus. Proc Natl Acad Sci U S A 2001 Feb 13;98(4):1889-94.
- Pasternak AO, Gultyaev AP, Spaan WJ, Snijder EJ. Genetic manipulation of arterivirus alternative mRNA leader-body junction sites reveals tight regulation of structural protein expression. J Virol 2000 Dec;74(24):11642-53.
- Molenkamp R, Greve S, Spaan WJ, Snijder EJ. Efficient homologous RNA recombination and requirement for an open reading frame during replication of equine arteritis virus defective interfering RNAs. J Virol 2000 Oct;74(19):9062-70.
- van Dinten LC, van Tol H, Gorbalenya AE, Snijder EJ. The predicted metal-binding region of the arterivirus helicase protein is involved in subgenomic mRNA synthesis, genome replication, and virion biogenesis. J Virol 2000 Jun;74(11):5213-23.
- Molenkamp R, Rozier BC, Greve S, Spaan WJ, Snijder EJ. Isolation and characterization of an arterivirus defective interfering RNA genome. J Virol 2000 Apr;74(7):3156-65.
- Lim KP, Ng LF, Liu DX. Identification of a novel cleavage activity of the first papain-like proteinase domain encoded by open reading frame 1a of the coronavirus Avian infectious bronchitis virus and characterization of the cleavage products. J Virol 2000 Feb;74(4):1674-85.
- van Marle G, Dobbe JC, Gultyaev AP, Luytjes W, Spaan WJ, Snijder EJ. Arterivirus discontinuous mRNA transcription is guided by base pairing between sense and antisense transcription-regulating sequences. Proc Natl Acad Sci U S A 1999 Oct 12;96(21):12056-61.
- van der Meer Y, Snijder EJ, Dobbe JC, Schleich S, Denison MR, Spaan WJ, Locker JK. Localization of mouse hepatitis virus nonstructural proteins and RNA synthesis indicates a role for late endosomes in viral replication. J Virol 1999 Sep;73(9):7641-57.
- Snijder EJ, van Tol H, Pedersen KW, Raamsman MJ, de Vries AA. Identification of a novel structural protein of arteriviruses. J Virol 1999 Aug;73(8):6335-45.
- van Marle G, van Dinten LC, Spaan WJ, Luytjes W, Snijder EJ. Characterization of an equine arteritis virus replicase mutant defective in subgenomic mRNA synthesis. J Virol 1999 Jul;73(7):5274-81.
- van Dinten LC, Rensen S, Gorbalenya AE, Snijder EJ. Proteolytic processing of the open reading frame 1b-encoded part of arterivirus replicase is mediated by nsp4 serine protease and Is essential for virus replication. J Virol 1999 Mar;73(3):2027-37.
- Pedersen KW, van der Meer Y, Roos N, Snijder EJ. Open reading frame 1a-encoded subunits of the arterivirus replicase induce endoplasmic reticulum-derived double-membrane vesicles which carry the viral replication complex. J Virol 1999 Mar;73(3):2016-26.
- Nelsen CJ, Murtaugh MP, Faaberg KS. Porcine reproductive and respiratory syndrome virus comparison: divergent evolution on two continents. J Virol 1999 Jan;73(1):270-80.
- Ziebuhr J, Siddell SG. Processing of the human coronavirus 229E replicase polyproteins by the virus-encoded 3C-like proteinase: identification of proteolytic products and cleavage sites common to pp1a and pp1ab. J Virol 1999 Jan;73(1):177-85.
- van der Meer Y, van Tol H, Locker JK, Snijder EJ. ORF1a-encoded replicase subunits are involved in the membrane association of the arterivirus replication complex. J Virol 1998 Aug;72(8):6689-98.
- Liu X, Ropp SL, Jackson RJ, Frey TK. The rubella virus nonstructural protease requires divalent cations for activity and functions in trans. J Virol 1998 May;72(5):4463-6.
- Schiller JJ, Kanjanahaluethai A, Baker SC. Processing of the coronavirus MHV-JHM polymerase polyprotein: identification of precursors and proteolytic products spanning 400 kilodaltons of ORF1a. Virology 1998 Mar 15;242(2):288-302.
- Kheyar A, Martin S, St-Laurent G, Timoney PJ, McCollum WH, Archambault D. Expression cloning and humoral immune response to the nucleocapsid and membrane proteins of equine arteritis virus. Clin Diagn Lab Immunol 1997 Nov;4(6):648-52.
- Bos EC, Luytjes W, Spaan WJ. The function of the spike protein of mouse hepatitis virus strain A59 can be studied on virus-like particles: cleavage is not required for infectivity. J Virol 1997 Dec;71(12):9427-33.
- Wassenaar AL, Spaan WJ, Gorbalenya AE, Snijder EJ. Alternative proteolytic processing of the arterivirus replicase ORF1a polyprotein: evidence that NSP2 acts as a cofactor for the NSP4 serine protease. J Virol 1997 Dec;71(12):9313-22.
- Piñón JD, Mayreddy RR, Turner JD, Khan FS, Bonilla PJ, Weiss SR. Efficient autoproteolytic processing of the MHV-A59 3C-like proteinase from the flanking hydrophobic domains requires membranes. Virology 1997 Apr 14;230(2):309-22.
- van Dinten LC, den Boon JA, Wassenaar AL, Spaan WJ, Snijder EJ. An infectious arterivirus cDNA clone: identification of a replicase point mutation that abolishes discontinuous mRNA transcription. Proc Natl Acad Sci U S A 1997 Feb 4;94(3):991-6.
- St-Laurent G, Lepage N, Carman S, Archambault D. Genetic and amino acid analysis of the GL protein of Canadian, American and European equine arteritis virus isolates. Can J Vet Res 1997 Jan;61(1):72-6.
- Lepage N, St-Laurent G, Carman S, Archambault D. Comparison of nucleic and amino acid sequences and phylogenetic analysis of the Gs protein of various equine arteritis virus isolates. Virus Genes 1996;13(1):87-91.
- van Dinten LC, Wassenaar AL, Gorbalenya AE, Spaan WJ, Snijder EJ. Processing of the equine arteritis virus replicase ORF1b protein: identification of cleavage products containing the putative viral polymerase and helicase domains. J Virol 1996 Oct;70(10):6625-33.
- Faaberg KS, Plagemann PG. Membrane association of the C-terminal half of the open reading frame 1a protein of lactate dehydrogenase-elevating virus. Arch Virol 1996;141(7):1337-48.
- den Boon JA, Kleijnen MF, Spaan WJ, Snijder EJ. Equine arteritis virus subgenomic mRNA synthesis: analysis of leader-body junctions and replicative-form RNAs. J Virol 1996 Jul;70(7):4291-8.
- Plagemann PG, Rowland RR, Even C, Faaberg KS. Lactate dehydrogenase-elevating virus: an ideal persistent virus?. Springer Semin Immunopathol 1995;17(2-3):167-86.
- den Boon JA, Faaberg KS, Meulenberg JJ, Wassenaar AL, Plagemann PG, Gorbalenya AE, Snijder EJ. Processing and evolution of the N-terminal region of the arterivirus replicase ORF1a protein: identification of two papainlike cysteine proteases. J Virol 1995 Jul;69(7):4500-5.