Characterization of a serine-to-asparagine substitution at position 123 in the Japanese encephalitis virus E protein.
Amino acid position 123 in the E protein of Japanese encephalitis virus (JEV) determines viral growth properties and pathogenicity. The majority of JEV strains have a serine residue at this position (E(123S)); however, JEV with an asparagine residue (E(123N)) has also been isolated. To compare the growth properties and pathogenicity of E(123S) and E(123N) JEV, we produced recombinant JEV with a serine-to-asparagine substitution at position 123 (rJEV-Mie41-E(S123N)) in the E(123S)-type strain Mie/41/2002 background. The growth rate of rJEV-Mie41-E(S123N) was similar to that of Mie/41/2002 in mammalian and mosquito cell lines. Mouse challenge experiments showed that there was only a slight difference in neuroinvasiveness between the parent strain (Mie/41/2002) and rJEV-Mie41-E(S123N). Thus, our results indicate that the Ser-to-Asn substitution in the JEV E protein has weak impact on viral growth properties in vitro or on pathogenicity in vivo.
Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.|Department of Pathology, Immunology and Microbiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.
Yukie
Y
Yamaguchi
Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.|Department of Infection Control and Prevention, University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo, Tokyo 113-8655, Japan.
Yoko
Y
Nukui
Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.
Akira
A
Kotaki
Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.
Kyoko
K
Sawabe
Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.
Masayuki
M
Saijo
Department of Pathology, Immunology and Microbiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.|National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.
Haruo
H
Watanabe
National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.
Ichiro
I
Kurane
Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.
Tomohiko
T
Takasaki
Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan.
Shigeru
S
Tajima
D019943:Amino Acid Substitution; D000818:Animals; D001216:Asparagine / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D009033:Culicidae / Q000821:virology; D004664:Encephalitis Virus, Japanese / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005260:Female; D051379:Mice; D010802:Phylogeny; D012694:Serine / Q000235:genetics* / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000378:metabolism
D014759:Viral Envelope Proteins; D012694:Serine; D001216:Asparagine