Summary
We examined the structural features and functional significance of a novel complex which forms between the envelope (E) protein and nonstructural protein NS1 of Murray Valley encephalitis (MVE) virus. Western blot analysis of virus-infected C6/36 cell lysates revealed that the undenatured form of this E-NS1 complex was a heat-sensitive E-(NS1 dimer) complex. Furthermore, the E-NS1 complex was observed in cells infected with Kunjin, Japanese encephalitis, West-Nile and Kokobera viruses which indicates the complex is a common feature of flavivirus infection. E-NS1 complex which had been immunoaffinity purified from MVE-infected cell lysates or eluted from gel slices exhibited partial breakdown into the individual monomers, demonstrating that the complex arose from the association of E and NS1 proteins and was not a single polypeptide created from incomplete gene cleavage. Radioimmunoprecipitation and western blot analysis of MVE-infected cell lysates and culture fluid preparations collected at various times after infection revealed that the E-NS1 complex has a long half life, accumulates in the virus-infected cell with time and is not secreted into the extracellular fluid. We have postulated that the E-NS1 complex, or at least a major portion of the complex, is a non-specific aggregation with no functional significance in the viral life cycle.
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References
Calisher CH, Karabatsos N, Dalrymple JM, Shope RE, Porterfield JS, Westaway EG, Brandt WE (1989) Antigenic relationships between flaviviruses, as determined by cross-neutralisation tests with polyclonal antisera. J Gen Virol 70: 37–43
Coelen RJ, Mackenzie JS (1988) Genetical variation of Murray Valley encephalitis virus. J Gen Virol 69: 1903–1912
Flamand M, Deubel V, Girard M (1992) Expression and secretion of Japanese encephalitis virus non-structural protein NS1 by insect cells using a recombinant baculovirus. Virology 191: 826–836
Gibson CA, Schlesinger JJ, Barrett ADT (1988) Prospects for a virus non-structural protein as a sub-unit vaccine. Vaccine 6: 7–10
Hall RA, Kay BH, Burgess GW, Clancy P, Fanning ID (1990) Epitope analysis of the envelope and non-structural glycoproteins of Murray Valley encephalitis virus. J Gen Virol 71: 2923–2930
Hall RA, Coelen RJ, Mackenzie JS (1991) Immunoaffinity purification of the NS1 protein of Murray Valley encephalitis virus: selection of the appropriate ligand and optimal conditions for elution. J Virol Methods 32: 11–20
Heinz FX (1986) Epitope mapping of flavivirus glycoproteins. Adv Virus Res 31: 103–123
Laemmli UK (1970) Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227: 680–685
Mason PW (1989) Maturation of Japanese encephalitis virus glycoproteins produced by infected mammalian and mosquito cells. Virology 169: 354–364
Mason PW, McAda PC, Dalrymple JM, Fournier MJ, Mason TC (1987) Expression of Japanese encephalitis virus antigens inEscherichia coli. Virology 158: 361–372
Nowak T, Wengler G (1987) Analysis of disulfides present in the membrane proteins of the West Nile flavivirus. Virology 156: 127–137
Rice CM, Lenches EM, Eddy SR, Shin SJ, Sheets R, Strauss JH (1985) Nucleotide sequence of Yellow Fever virus: implications for flavivirus gene expression and evolution. Science 229: 726–733
Rice CM, Strauss EG, Strauss JH (1986) Structure of the flavivirus genome. In: Schlesinger S, Schlesinger MJ (eds) The togaviridae and flaviviridae. Plenum Press, New York, pp 276–326
Schlesinger JJ, Brandriss MW, Walsh EE (1985) Protection against 17D Yellow Fever encephalitis in mice by passive transfer of monoclonal antibodies to the nonstructural glycoprotein gp48 and by active immunisation with gp48. J Immunol 135: 2805–2809
Schlesinger JJ, Brandriss MW, Cropp C, Monath TP (1986) Protection against Yellow Fever in monkeys by immunisation with the yellow fever virus non-structural protein NS1. J Virol 60: 1153–1155
Speight G, Coia G, Parker MD, Westaway EG (1988) Gene mapping and positive identification of the nonstructural proteins NS2A, NS2B, NS3, NS4B and NS5 and the flavivirus Kunjin and their cleavage sites. J Gen Virol 69: 23–34
Towbin H, Staehelin T, Gordon J (1979) Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci USA 76: 4350–4354
Westaway E (1987) Flavivirus replication strategy. Adv Virus Res 33: 45–90
Winkler G, Randolph VB, Cleaves GR, Ryan TE, Stollar V (1988) Evidence that the mature form of the flavivirus nonstructural protein NS1 is a dimer. Virology 162: 187–196
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Blitvich, B.J., Mackenzie, J.S., Coelen, R.J. et al. A novel complex formed between the flavivirus E and NS1 proteins: analysis of its structure and function. Archives of Virology 140, 145–156 (1995). https://doi.org/10.1007/BF01309729
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DOI: https://doi.org/10.1007/BF01309729