Two interleukin (IL)-15 homologues in fish from two distinct origins
Two interleukin (IL)-15 homologues in fish from two distinct origins
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DOI：
10.1016/j.molimm.2005.06.040
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发表时间：
2006-03-01
影响因子：
3.6
通讯作者：
Suzuki, Y
中科院分区：
文献类型：
--
作者：
Bei, JX;Suetake, H;Suzuki, Y
在这里，我们报告两个不同的基因在硬骨鱼是同源的白细胞介素（IL）-15。从红鳍东方鲀（Takifugu rubripes）分离的这两个基因与哺乳动物IL-15相似，但在氨基酸序列上与IL-2和IL-21不同，具有特殊的艾奥纳信号肽和更广泛的组织定位。此外，在这两个基因的5 '-UTR中还检测到多个框外AUG密码子，这是哺乳动物IL-15基因的负翻译调控因子。河豚IL-15同源物还含有四个保守的半胱氨酸，允许与四个预测的α-螺旋一起形成两个二硫键沿着。基因组分析表明，其中一个河豚IL-15同源基因具有6个编码外显子，并表现出与哺乳动物和鸡IL-15基因相似的外显子-内含子组织和同线性结构。相反，另一个河豚IL-15同源物具有四个外显子，并表现出与IL-15不同的同线性结构，表明这两个基因来自两个不同的来源。此外，这两个基因在组织定位和对有丝分裂原的反应表达方面也彼此不同。这两种IL-15同系物在斑马鱼中的存在进一步得到了斑马鱼和绿斑河豚中IL-15同系物的表征。在鱼类中发现两种不同的IL-15同源物将有助于调查这些基因的进化及其对鱼类免疫系统的相对贡献。(C)2005爱思唯尔有限公司保留所有权利。
Here, we report two distinct genes in teleosts that are homologous to interleukin (IL)-15. The two genes, isolated from fugu (Takifugu rubripes), resemble to mammalian IL-15 but differ from IL-2 and IL-21 in their amino acid sequences, the possessing of an extraordinary Iona, signal peptide and more widespread tissue localization. In addition, multiple out-of-frame AUG codons, the negative translational regulators of mammalian IL-15 genes were also detected in the 5'-UTR of the two genes. Fugu IL-15 homologues also contain four conserved cysteines allowing the formation of two disulfide bridges along with four predicted a-helices. Genomic analysis showed that one of the fugu IL-15 homologues possessed six coding exons and exhibited a similar exon-intron organization and synteny structure to that of mammalian and chicken IL-15 genes. Conversely, the other fugu IL-15 homologue possesses four exons and exhibits a different synteny structure with that of IL-15, suggesting that the two genes were derived from two different origins. Moreover, the two genes also differ from each other in tissue localizations and in their expression in response to mitogens. The existence of these two IL-15 homologues in telesots was further supported by their characterization in zebrafish Danio rerio, and the green-spotted pufferfish Tetraodon nigroviridis. The discovery of two distinct IL-15 homologues in fish will assist investigations into the evolution of these genes and their relative contribution to the fish immune system. (C) 2005 Elsevier Ltd. All rights reserved.