Iliev Dimitar B, Castellana Barbara, Mackenzie Simon, Planas Josep V, Goetz Frederick W
Great Lakes WATER Institute, University of Wisconsin Milwaukee, 600 E. Greenfield Avenue, Milwaukee, WI 53204, USA.
Mol Immunol. 2007 Mar;44(7):1803-7. doi: 10.1016/j.molimm.2006.07.297. Epub 2006 Oct 12.
A partial cDNA with significant similarity to IL-6 was identified in rainbow trout. Rapid amplification of cDNA ends was used to obtain the full sequence of the trout IL-6 homolog which contains 1180 nucleotides. The transcript encodes a predicted protein of 219 amino acids and eight instability motifs in the 3'UTR. While the complete sequence of the trout IL-6 is poorly conserved, the protein contains a distinct IL-6/G-CSF/MGF family consensus pattern and predicted characteristic alpha-helical tertiary structure. However, like in fugu, trout IL-6 lacks a pair of cysteine residues, which in mammals are involved in formation of a disulphide bond. The expression of the IL-6 homolog in trout mononuclear phagocytes was highly up-regulated by LPS but not poly(I:C) as demonstrated by Northern analysis. Using RT-PCR the IL-6 expression was detected in trout spleen, gill, gastrointestinal tract, ovary and brain. The highest transcript levels were detected in the ovary suggesting that IL-6 may perform specific functions within this organ.
在虹鳟鱼中鉴定出了一段与白细胞介素-6（IL-6）具有显著相似性的部分互补DNA（cDNA）。采用cDNA末端快速扩增技术获得了虹鳟鱼IL-6同源物的完整序列，该序列包含1180个核苷酸。该转录本编码一个由219个氨基酸组成的预测蛋白，其3'非翻译区（3'UTR）有八个不稳定基序。虽然虹鳟鱼IL-6的完整序列保守性较差，但该蛋白含有独特的IL-6/粒细胞集落刺激因子（G-CSF）/巨噬细胞生长因子（MGF）家族共有模式以及预测的特征性α螺旋三级结构。然而，与河豚一样，虹鳟鱼IL-6缺乏一对半胱氨酸残基，而在哺乳动物中这对半胱氨酸残基参与二硫键的形成。Northern分析表明，虹鳟鱼单核吞噬细胞中IL-6同源物的表达受脂多糖（LPS）高度上调，但不受聚肌苷酸-聚胞苷酸（poly(I:C)）上调。利用逆转录-聚合酶链反应（RT-PCR）在虹鳟鱼的脾脏、鳃、胃肠道、卵巢和脑中检测到了IL-6的表达。在卵巢中检测到的转录本水平最高，这表明IL-6可能在该器官内发挥特定功能。
