Molecular characterization and expression analysis of an inhibitor of NF-κB (IκB) from Asiatic hard clam Meretrix meretrix

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• 作者：Qing Yang^a ; Zhi Yang^a ; Hongjun Li^a ; ^b ; ^{oceanlhj@163.com"" rel=""nofollow}
• 关键词：Meretrix meretrix ; I&#x3ba ; B ; NF-&#x3ba ; B ; mRNA level ; Ankyrin repeat
• 刊名：Fish & Shellfish Immunology
• 出版年：2011
• 出版时间：September 2011
• 年：2011
• 卷：31
• 期：3
• 页码：485-490
• 全文大小：655 K

文摘

Inhibitor of NF-κB (IκB) is an important member of Rel/NF-κB signaling pathway, which is an important mediator of immune responses in innate immune system. In this study, the IκB cDNA of hard clam Meretrix meretrix (designated as Mm-IκB) was cloned and characterized. The full-length cDNA of Mm-IκB was of 2098 bp, containing a 5′ untranslated region (UTR) of 123 bp, a 3′ UTR of 810 bp with a poly (A) tail, and an open reading frame (ORF) of 1164 bp encoding a polypeptide of 387 amino acids. The high similarity of Mm-IκB with other IκBs from invertebrates indicated that Mm-IκB should be a member of IκB family. Similar to most IκBs, Mm-IκB possessed all conserved features critical for the fundamental structure and function of IκBs, such as five ankyrin repeats and a conserved degradation motif (DS₄₄RYSS₄₈). Two PEST domains and a phosphorylation site motif (S₃₆₇EEE₃₇₀) at the C-terminus of Mm-IκB were identified. By quantitative real-time RT-PCR analysis, mRNA level of Mm-IκB was found to be most abundantly expressed in the tissues of mantle, gill and hepatopancreas, weakly expressed in muscle, foot and haemocyte. The Mm-IκB gene expression was significantly up-regulated at 24 h in haemocyte and at 12 h in gill after Vibrio anguillarum challenge, respectively. The results suggested the involvement of Mm-IκB in response against bacterial infection and further highlighted its functional importance in the immune system of M. meretrix.