Characterization of the interaction between arginine kinase and siRNA.

RNAi, a crucial pathway in animals to defend against virus infection, is mediated directly by RNA-induced silencing complex (RISC) in an ATP-dependent manner. The RISC comprises one strand of short interfering RNA (siRNA) and multiprotein including Argonaute protein, which can cleave target RNAs. However, the proteins interacted with siRNA are not extensively explored. In this study, an antiviral siRNA (vp28-siRNA) targeting the vp28 gene of shrimp white spot syndrome virus was characterized. Based on the biotin/streptavidin affinity screening, it was found that the shrimp arginine kinase was specifically bound with the vp28-siRNA. The co-immunoprecipitation assays revealed that the siRNA was directly interacted with arginine kinase, suggesting that arginine kinase was an essential component of RNA-induced silencing complex. Therefore, our study presented a novel finding on the RISC components, which would be helpful to reveal the molecular events in the RNAi pathway.