Inhibition of nervous necrosis virus propagation by fish Mx proteins.
Mx proteins are interferon induced, antiviral proteins, expressed in response to treatment with double stranded RNA or virus infection. Here we report the cloning, sequencing, and antiviral property of three forms of Mx genes, MxI, MxII, and MxIII from grouper (Epinephelus coioides). Multiple comparison of grouper Mx amino acid sequences revealed the conservation of Mx putative GTP-binding domain, dynamin family signature, and leucine zipper motif. We have established a new cell line, grouper brain 3 (GB3), and prepared stable clones expressing Flag-epitope tagged grouper MxI, MxII, and MxIII. Immunostaining shows that all the three grouper Mx proteins are localized in the cytoplasm. To examine the antiviral activity of grouper Mx proteins, these stable clones were infected by a nodavirus, yellow grouper nervous necrosis virus (YGNNV), and the results showed that all the three Mx isoforms have the efficiency of reducing the titre of virus from 10- to 100-fold. Moreover, through immunocytochemistry we demonstrated that Mx protein can inhibit the YGNNV propagation in GB3 cells. Taken together, this study demonstrates that grouper Mx proteins have efficient inhibitory activity against nodavirus, the most endangered virus of fish, and this information would be helpful to design effective DNA vaccines that can confer an early non-specific antiviral protection.
Lin
Chih-Hung
CH
Molecular Genetics Laboratory, Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
Christopher John
Joseph Abraham
JA
Lin
Cheng-Hui
CH
Chang
Chi-Yao
CY
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D030381:Nodaviridae / Q000502:physiology*; D010473:Perciformes / Q000378:metabolism* / Q000821:virology; D014779:Virus Replication
D029941:Fish Proteins; D019204:GTP-Binding Proteins