IRF11 enhances the inhibitory effect of IκBα on NF-κB activation in miiuy croaker

NF-kappa B is a typical transcription factor that regulates expression of various genes involved in inflammatory and immune responses. Therefore, it is essential that NF-kappa B signaling tightly regulated to maintain immune balance. Compared with those of mammals, the regulatory mechanisms of NF-kappa B signaling is rarely reported in teleost fish. I kappa B alpha is a prominent negative feedback regulator in the NF-kappa B signaling system. In this study, we determined that IRF11 enhances the inhibitory effect of I kappa B alpha on NF-kappa B activation in teleost fish. Overexpression of IRF11 can inhibit I kappa B alpha degradation, whereas its knockdown has the opposite effect of I kappa B alpha. Our study further indicates that I kappa B alpha was regulated via ubiquitin-proteasome degradation pathway, IRF11 inhibits I kappa B alpha in ubiquitin-proteasome degradation. This study provides a novel evidence on the regulation of innate immune signaling pathways in teleost fish and thus provides new insights into the regulatory mechanisms in mammals.