Nucleolar protein B23 interacts with Japanese encephalitis virus core protein and participates in viral replication.
Japanese encephalitis virus (JEV) core protein is detected not only in the cytoplasm but also in the nucleoli of infected cells. We previously showed that a mutant JEV lacking the nucleolar localization of the core protein impaired viral replication in mammalian cells. In this study, we identified a nucleolar phosphoprotein B23 as a protein binding with the core protein of JEV but not with that of dengue virus. The region binding with JEV core protein was mapped to amino acid residues 38 to 77 of B23. Upon JEV infection, some fraction of B23 was translocated from the nucleoli to the cytoplasm, and cytoplasmic B23 was colocalized with the core protein of wild-type JEV but not with that of the mutant JEV. Furthermore, overexpression of dominant negatives of B23 reduced JEV replication. These results suggest that B23 plays an important role in the intracellular localization of the core protein and replication of JEV.
Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.
Yoshimi
Y
Tsuda
Yoshio
Y
Mori
Takayuki
T
Abe
Tetsuo
T
Yamashita
Toru
T
Okamoto
Tohru
T
Ichimura
Kohji
K
Moriishi
Yoshiharu
Y
Matsuura
D000818:Animals; D002460:Cell Line; D002466:Cell Nucleolus / Q000378:metabolism*; D002522:Chlorocebus aethiops; D004664:Encephalitis Virus, Japanese / Q000378:metabolism* / Q000502:physiology*; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000090243:Nucleophosmin; D014709:Vero Cells; D014758:Viral Core Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D014758:Viral Core Proteins; D000090243:Nucleophosmin