RGNNV induces mitochondria-mediated cell death via newly synthesized protein dependent pathway in fish cells.
The RNA nervous necrosis virus induces necrotic cell death in fish; however, the molecular mechanism remains unknown. In this study, we demonstrated that beta-nodavirus-induced mitochondria-mediated dependent cell death is through newly synthesized protein dependent pathway in replication cycle. We determined that newly synthesized protein dependent pathway is required for red-spotted grouper nervous necrosis virus (RGNNV)-induced cell death. UV irradiation of the virus effectively blocked viral replication and cell death. Next, RGNNV RNA-dependent RNA polymerase (RdRp or protein A) was cloned and its involvement in RNA genome replication and viral protein synthesis was analyzed. Protein A was initially expressed 48 h post-infection and localized to the cytoplasm. Knockdown of protein A expression completely blocked viral genomic replication and expression of viral protein expression RNA1 small hairpin RNA (shRNA) producing cell lines, which coincided with inhibition of phosphatidylserine exposure, mitochondria-mediated death signaling, and increased cell viability 72 h post-infection. Furthermore, RGNNV-induced mitochondria-mediated caspase-3-independent necrotic cell death is dependent on viral synthesized protein dependent pathway at the middle-late replication stage. Taken together, for instance these results suggested that RGNNV induces cell death may require newly synthesized protein for triggering host mitochondria-mediated cell death. These findings may provide new insights into RNA viral pathogenesis.
Wu
Horng-Cherng
HC
Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan, ROC.
Wu
Jen-Leih
JL
Chu
Heuy-Ling
HL
Su
Yu-Chin
YC
Hong
Jiann-Ruey
JR
D000595:Amino Acid Sequence; D000818:Animals; D016923:Cell Death; D002460:Cell Line; D003001:Cloning, Molecular; D005393:Fish Diseases / Q000378:metabolism*; D015967:Gene Expression Regulation, Viral; D055785:Gene Knockdown Techniques; D016679:Genome, Viral / Q000235:genetics; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D030381:Nodaviridae / Q000502:physiology*; D012327:RNA Virus Infections / Q000378:metabolism / Q000662:veterinary*; D034741:RNA, Small Interfering / Q000378:metabolism; D016415:Sequence Alignment; D013205:Staphylococcal Protein A / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism*
D034741:RNA, Small Interfering; D013205:Staphylococcal Protein A; D014764:Viral Proteins