The IκB kinases IKKα and IKKβ and the IKK-related kinases TANK-binding kinase 1 （TBK1） and IKKε are the master regulators of the NF-κB signaling pathway. Although this pathway has been extensively studied in ma...The IκB kinases IKKα and IKKβ and the IKK-related kinases TANK-binding kinase 1 （TBK1） and IKKε are the master regulators of the NF-κB signaling pathway. Although this pathway has been extensively studied in mammals, less attention has been paid in crustaceans, which have significant economic value. Here, we report the cloning and functional studies of two IKK homologs, LvlKKβ and LvlKKε, from Pacific white shrimp, Litopenaeus vannamei. LvlKKβ and LvlKKα mRNAs are widely expressed in different tissues and are responsive to white spot syndrome virus （WSSV） infection. When overexpressed in Drosophila S2 cells, LvlKKβ but not LvlKKε activates the promoters of NF-κB pathway-controlled antimicrobial peptide genes （AMPs）, such as the Penaeidins （PENs）. In HEK 293T cells, both LvlKKβ and LvlKKε activate an NF-κB reporter. The silencing of LvlKKβ or LvlKKε using double-stranded RNA （dsRNA）-mediated RNA interference （RNAi） decreases the expression of L. vannamei AMPs, including PENs, lysozyme and crustins. Intriguingly, LvlKKβ- or LvlKKε-silenced L. vannameiare resistant to WSSV infection. We hypothesized that successful infection with WSSV requires the activation of the IKK-NF-κB signaling pathway to modulate viral gene expression. We constructed luciferase reporters for 147 WSSV genes. By screening, we found that the WSSV051, WSSV059, WSSV069, WSSV083, WSSV090, WSSV107, WSSV244, WSSV303, WSSV371 and WSSV445 promoters can be activated by LvlKKβ or LvlKKε in Drosophila S2 cells. Taken together, our results reveal that LvlKKβ and LvlKKε may participate in the regulation of shrimp AMPs and that WSSV may subvert the L. vannamei IKK-NF-κB signaling pathway to facilitate viral gene expression.展开更多
文摘The IκB kinases IKKα and IKKβ and the IKK-related kinases TANK-binding kinase 1 （TBK1） and IKKε are the master regulators of the NF-κB signaling pathway. Although this pathway has been extensively studied in mammals, less attention has been paid in crustaceans, which have significant economic value. Here, we report the cloning and functional studies of two IKK homologs, LvlKKβ and LvlKKε, from Pacific white shrimp, Litopenaeus vannamei. LvlKKβ and LvlKKα mRNAs are widely expressed in different tissues and are responsive to white spot syndrome virus （WSSV） infection. When overexpressed in Drosophila S2 cells, LvlKKβ but not LvlKKε activates the promoters of NF-κB pathway-controlled antimicrobial peptide genes （AMPs）, such as the Penaeidins （PENs）. In HEK 293T cells, both LvlKKβ and LvlKKε activate an NF-κB reporter. The silencing of LvlKKβ or LvlKKε using double-stranded RNA （dsRNA）-mediated RNA interference （RNAi） decreases the expression of L. vannamei AMPs, including PENs, lysozyme and crustins. Intriguingly, LvlKKβ- or LvlKKε-silenced L. vannameiare resistant to WSSV infection. We hypothesized that successful infection with WSSV requires the activation of the IKK-NF-κB signaling pathway to modulate viral gene expression. We constructed luciferase reporters for 147 WSSV genes. By screening, we found that the WSSV051, WSSV059, WSSV069, WSSV083, WSSV090, WSSV107, WSSV244, WSSV303, WSSV371 and WSSV445 promoters can be activated by LvlKKβ or LvlKKε in Drosophila S2 cells. Taken together, our results reveal that LvlKKβ and LvlKKε may participate in the regulation of shrimp AMPs and that WSSV may subvert the L. vannamei IKK-NF-κB signaling pathway to facilitate viral gene expression.
