College of Life Science, Liaoning Normal University, Dalian 116029, China.
Fish Shellfish Immunol. 2013 Oct;35(4):1146-54. doi: 10.1016/j.fsi.2013.07.026. Epub 2013 Aug 2.
Nuclear factor of kappa B (NF-κB) is a stimuli-activated transcription factor, regulates the expression of a diverse array of genes. Inhibitor of kappa B-epsilon (IκB-ε) is an inhibitor of NF-κB, which retains NF-κB in an inactive state in the cytoplasm. Lampreys (Lampetra japonica) belong to the lowest class of vertebrates with little information about its IκBs. We have identified a cDNA sequence IκB-ε-like in the lamprey and the deduced amino acid sequence of IκB-ε-like. It contains a conserved DSGxxS motif and six consecutive ankyrin repeats, which are necessary for signal-induced degradation of the molecule. Phylogenetic analysis indicated it had high sequence homology with IκB-εs from other vertebrates. FACS analysis showed that IκB-ε-like located in cytoplasm of leukocytes. The degradation of IκB-ε-like could be observed in leukocytes of L. japonica stimulated with lipopolysaccharide. These results indicate that IκB-ε proteins are conserved across vertebrates and the NF-κB-like signaling pathway may exist in the oldest agnatha.
核因子-κB（NF-κB）是一种刺激激活的转录因子，调节多种基因的表达。κB 抑制蛋白-ε（IκB-ε）是 NF-κB 的抑制剂，它将 NF-κB 保留在细胞质中的非活性状态。七鳃鳗（Lampetra japonica）属于最低等的脊椎动物，关于其 IκBs 的信息很少。我们已经在七鳃鳗中鉴定出一个 IκB-ε 样 cDNA 序列，并且推导出 IκB-ε 样的氨基酸序列。它含有一个保守的 DSGxxS 基序和六个连续的锚蛋白重复序列，这些序列对于信号诱导的分子降解是必需的。系统发育分析表明，它与其他脊椎动物的 IκB-ε 具有很高的序列同源性。FACS 分析表明，IκB-ε 样位于白细胞的细胞质中。在 LPS 刺激的七鳃鳗白细胞中可以观察到 IκB-ε 样的降解。这些结果表明，IκB-ε 蛋白在脊椎动物中是保守的，并且 NF-κB 样信号通路可能存在于最古老的无颌类动物中。
