The alpha inhibitor of NF- mu B (I mu B alpha ) from the mandarin fish binds with p65 NF- mu B

摘要

The NF- Kappa B/I Kappa B alpha pathway plays an important role in the regulation of immune and inflammatory responses. I Kappa B alpha is an inhibitory molecule that sequesters transcription activator NF- Kappa B dimer in the cytoplasm of unstimulated cells. Here, we isolated the full-length cDNAs of the mandarin fish (Siniperca chuatsi) alpha inhibitor of NF- Kappa B (ScI Kappa B alpha ) and p65 NF- Kappa B (Scp65). Multiple sequence alignments showed that the amino acid sequences of both ScI Kappa B alpha and Scp65 contain conserved domains similar to those of mammalian counterparts. Protein pull-down and coimmunoprecipitation assays showed that ScI Kappa B alpha directly bound with Scp65. Real-time quantitative PCR analysis showed that ScI Kappa B alpha mRNA was constitutive in all mandarin fish tissues detected. After challenge with infectious spleen and kidney necrosis virus (ISKNV), the mRNA level of ScI Kappa B alpha was decreased nearly 6 fold in the spleen. This result suggests that the NF- Kappa B/I Kappa B alpha pathway in mandarin fish may play a role in the immune response against ISKNV.