Antiviral Function Of COP9 Signalosome Subunit 5 In Marsupenaeus Japonicus

Neddylation is a reversible post-translational modification and the ubiquitin-like protein NEDD8(neural precursor cell expressed developmentally down-regulated 8)is conjugated to lysine residues in the target protein.Like Ubiquitination,Neddylation requires the activating enzyme El,conjugating enzyme E2 and ligase enzyme E3,and then modified the target proteins specificly.The reverse reaction to neddylation is Deneddylation.The COP9(Constitutive photomorphogenesis 9)signalosome(CSN)mediated the process of Deneddylation.CSN is composed of eight subunits(CSN1-8).The fifth subunit of COP9 signalosome,CSN5,have obvious characteristics compared with the other seven subunits,the catalytic active sites and zinc ion binding sites.CSN5 played an important role in the function of CSN.However,the function of CSN5 in antiviral immunity is not clear.In this paper,we identified 7 subunits(CSN1-2 and CSN4-8)of COP9 signalosome in shrimp.Their tissue distribution and expression patterns in kuruma shrimp Marsupenaeus japonicus challenged by white spot syndrome virus(WSSV)were analyzed.The result showed that MjCSNl-2 and MjCSN4-6 were existed in all tested tissues,MjCSN7 and MjCSN8 were existed in all tested tissues except in hepatopancreas.After WSSV challenged,the expression level of MjCSNl,MjCSN2,MjCSN4 and MjCSN7,MjCSN8 were highly decreased,but the expression level of MjCSN5 was conspicuously increased.We found that the expression level of CSN5 was obviously different from other subunits post challenge by WSSV.Therefore,we focused our study on the CSN5(designated as MjCSN5)in the shrimp.MjCSN5 was recombinantly expressed in Escherichia coli and its polyclonal antibody was prepared.RNA interference and overexpression of MjCSN5 were also perfored.After knockdown of CSN5,the amount of WSSV In shrimp was obviously increased.When injected the recombinant protein of MjCSN5 with membrane penetrating peptide into shrimp,WSSV replication was inhibited and the survival rate of shrimp was significantly improved comparied with the control.These results indicate that CSN5 can inhibit the replication of WSSV in shrimp,and might be used in shrimp aquaculture for the white spot syndrome disease control.