scholarly journals Identification of heat-shock protein 90 beta in Japanese encephalitis virus-induced secretion proteins

2011 ◽  
Vol 92 (12) ◽  
pp. 2803-2809 ◽  
Author(s):  
Chun-Yu Hung ◽  
Meng-Chieh Tsai ◽  
Yi-Ping Wu ◽  
Robert Y. L. Wang
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Molecular Chaperones ◽  
Heat Shock Protein 90 ◽  
Rna Replication ◽  
Hsp90 Inhibitor ◽  
Encephalitis Virus ◽  
Virus Infectivity ◽  
Density Fractionation ◽  
Virus Particles

Five host cellular proteins were identified in the secretion medium from Japanese encephalitis virus (JEV)-infected baby hamster kidney-21 (BHK-21) cells, including three molecular chaperones: Hsp70, GRP78 and Hsp90. Hsp90 isoforms were characterized further. Hsp90α was observed to be retained inside the nuclei, whereas Hsp90β associated with virus particles during assembly and was released into the secretion medium upon JEV infection. The association of Hsp90β and viral E protein was demonstrated by using sucrose-density fractionation and Western blot analysis. Moreover, JEV viral RNA replication was not affected by treatment with geldanamycin, an Hsp90 inhibitor, but impaired virus infectivity that was determined by a plaque-forming assay. Our results show that Hsp90β, not Hsp90α, is present in the JEV-induced secretion medium and is required for JEV infectivity in BHK-21 cells.

scholarly journals Human MxB Inhibits the Replication of Hepatitis C Virus

2018 ◽  
Vol 93 (1) ◽  
Author(s):  
Dong-Rong Yi ◽  
Ni An ◽  
Zhen-Long Liu ◽  
Feng-Wen Xu ◽  
Kavita Raniga ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Dengue Virus ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Rna Replication ◽  
Encephalitis Virus ◽  
Common Mechanism ◽  
Type I ◽  
Dependent Manner

ABSTRACTType I interferon (IFN) inhibits viruses by inducing the expression of antiviral proteins. The IFN-induced myxovirus resistance B (MxB) protein has been reported to inhibit a limited number of viruses, including HIV-1 and herpesviruses, but its antiviral coverage remains to be explored further. Here we show that MxB interferes with RNA replication of hepatitis C virus (HCV) and significantly inhibits viral replication in a cyclophilin A (CypA)-dependent manner. Our data further show that MxB interacts with the HCV protein NS5A, thereby impairing NS5A interaction with CypA and NS5A localization to the endoplasmic reticulum, two events essential for HCV RNA replication. Interestingly, we found that MxB significantly inhibits two additional CypA-dependent viruses of theFlaviviridaefamily, namely, Japanese encephalitis virus and dengue virus, suggesting a potential link between virus dependence on CypA and virus susceptibility to MxB inhibition. Collectively, these data have identified MxB as a key factor behind IFN-mediated suppression of HCV infection, and they suggest that other CypA-dependent viruses may also be subjected to MxB restriction.IMPORTANCEViruses of theFlaviviridaefamily cause major illness and death around the world and thus pose a great threat to human health. Here we show that IFN-inducible MxB restricts several members of theFlaviviridae, including HCV, Japanese encephalitis virus, and dengue virus. This finding not only suggests an active role of MxB in combating these major pathogenic human viruses but also significantly expands the antiviral spectrum of MxB. Our study further strengthens the link between virus dependence on CypA and susceptibility to MxB restriction and also suggests that MxB may employ a common mechanism to inhibit different viruses. Elucidating the antiviral functions of MxB advances our understanding of IFN-mediated host antiviral defense and may open new avenues to the development of novel antiviral therapeutics.

scholarly journals 3′ cis-Acting Elements That Contribute to the Competence and Efficiency of Japanese Encephalitis Virus Genome Replication: Functional Importance of Sequence Duplications, Deletions, and Substitutions

2009 ◽  
Vol 83 (16) ◽  
pp. 7909-7930 ◽  
Author(s):  
Sang-Im Yun ◽  
Yu-Jeong Choi ◽  
Byung-Hak Song ◽  
Young-Min Lee
Keyword(s):  
Viral Replication ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Rna Replication ◽  
Encephalitis Virus ◽  
Protein Accumulation ◽  
Genomic Rna ◽  
Human Neuroblastoma ◽  
Lethal Mutant ◽  
Positive Strand Rna

ABSTRACT The positive-strand RNA genome of Japanese encephalitis virus (JEV) terminates in a highly conserved 3′-noncoding region (3′NCR) of six domains (V, X, I, II-1, II-2, and III in the 5′-to-3′ direction). By manipulating the JEV genomic RNA, we have identified important roles for RNA elements present within the 574-nucleotide 3′NCR in viral replication. The two 3′-proximal domains (II-2 and III) were sufficient for RNA replication and virus production, whereas the remaining four (V, X, I, and II-1) were dispensable for RNA replication competence but required for maximal replication efficiency. Surprisingly, a lethal mutant lacking all of the 3′NCR except domain III regained viability through pseudoreversion by duplicating an 83-nucleotide sequence from the 3′-terminal region of the viral open reading frame. Also, two viable mutants displayed severe genetic instability; these two mutants rapidly developed 12 point mutations in domain II-2 in the mutant lacking domains V, X, I, and II-1 and showed the duplication of seven upstream sequences of various sizes at the junction between domains II-1 and II-2 in the mutant lacking domains V, X, and I. In all cases, the introduction of these spontaneous mutations led to an increase in RNA production that paralleled the level of protein accumulation and virus yield. Interestingly, the mutant lacking domains V, X, I, and II-1 was able to replicate in hamster BHK-21 and human neuroblastoma SH-SY5Y cells but not in mosquito C6/36 cells, indicating a cell type-specific restriction of its viral replication. Thus, our findings provide the basis for a detailed map of the 3′ cis-acting elements in JEV genomic RNA, which play an essential role in viral replication. They also provide experimental evidence for the function of 3′ direct repeat sequences and suggest possible mechanisms for the emergence of these sequences in the 3′NCR of JEV and perhaps in other flaviviruses.

scholarly journals Mov34 Protein from Mouse Brain Interacts with the 3′ Noncoding Region of Japanese Encephalitis Virus

2000 ◽  
Vol 74 (11) ◽  
pp. 5108-5115 ◽  
Author(s):  
Malancha Ta ◽  
Sudhanshu Vrati
Keyword(s):  
Japanese Encephalitis Virus ◽  
Mouse Brain ◽  
Japanese Encephalitis ◽  
Rna Replication ◽  
Encephalitis Virus ◽  
Neonatal Mouse ◽  
Stem Loop ◽  
Brain Cdna Library ◽  
Molecular Masses ◽  
Northwestern Blotting

ABSTRACT The plus-sense RNA genome of Japanese encephalitis virus (JEV) contains noncoding regions (NCRs) of 95 and 585 bases at its 5′ and 3′ ends, respectively. The last 83 nucleotides of the 3′-NCR are predicted to form stable stem-loop (SL) structures. The shape of this 3′-SL structure is highly conserved among divergent flaviviruses even though only small stretches of nucleotide sequence contained within these structures are conserved. These SL structures have been predicted to function as cis-acting signals for RNA replication and as such may bind to viral and cellular proteins that may be involved in viral replication. We have studied the interaction of the JEV 3′-NCR RNA with host proteins using gel retardation assays. We show that the JEV 3′-SL structure RNA forms three complexes with proteins from the S100 cytoplasmic extract prepared from the neonatal mouse brain. These complexes could be obtained in the presence of 200 mM KCl, indicating that the RNA-protein interaction may be physiologically relevant. UV-induced cross-linking and Northwestern blotting analyses detected three proteins with apparent molecular masses of 32, 35, and 50 kDa that bound to the JEV 3′-SL structure RNA. Screening of the neonatal mouse brain cDNA library with the JEV 3′-SL structure RNA identified a 36-kDa Mov34 protein interacting with it. Competition experiments using the RNA extracted from JEV virions established that the 36-kDa Mov34 protein indeed bound to the JEV genome. Murine Mov34 belongs to a family of proteins whose members have been shown to be involved in RNA transcription and translation. It is, therefore, likely that the murine Mov34 interaction with JEV 3′-NCR has a role in RNA replication.

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