Lin Hui-Fang, Shao Jian-Zhong, Xiang Li-Xin, Wang Hui-Ju
College of Life Sciences, Zhejiang University, Hangzhou 310012, People's Republic of China.
Fish Shellfish Immunol. 2006 Oct;21(4):385-92. doi: 10.1016/j.fsi.2006.01.003. Epub 2006 Mar 13.
NF45 (ILF2) and NF90 (ILF3) regulate the IL-2 gene transcription via interaction with the antigen receptor response element. Much work on NF45 has been done in human and mammals while little in fish. In the present study, we have cloned and characterized the full-length cDNA of NF45 in grass carp (Ctenopharyngodon idellus). The grass carp NF45 cDNA of 1563bp contains a short 5'UTR of 24bp, a 3'UTR of 375bp and an open reading frame of 1164bp coding for a protein of 387 aa with a predicted molecular mass of 42.8kDa. The encoded protein shares 86.3-96.7% identities to other homologues. RT-PCR was optimized to estimate the expression level of NF45 in grass carp. The results showed that NF45 is constitutively expressed in most selected tissues, including head kidney, spleen, heart, brain, liver, and gill, although low levels were observed in spleen, liver and gill. The ubiquitous expression of NF45 is consistent with a postulated role in gene regulation at the level of transcription. Stimulating the fish with PHA significantly up-regulated the expression of NF45 in most tissues examined, which potentially indicated that NF45 was involved in the immune responses triggered by PHA.
NF45（ILF2）和NF90（ILF3）通过与抗原受体反应元件相互作用来调节白细胞介素-2基因转录。关于NF45的许多研究工作是在人类和哺乳动物中开展的，而在鱼类中的研究较少。在本研究中，我们克隆并鉴定了草鱼（Ctenopharyngodon idellus）NF45的全长cDNA。草鱼NF45 cDNA全长1563bp，包含一个24bp的短5'UTR、一个375bp的3'UTR和一个1164bp的开放阅读框，编码一个387个氨基酸的蛋白质，预测分子量为42.8kDa。编码的蛋白质与其他同源物的同一性为86.3-96.7%。优化了RT-PCR以评估草鱼中NF45的表达水平。结果表明，NF45在大多数选定组织中组成性表达，包括头肾、脾脏、心脏、脑、肝脏和鳃，尽管在脾脏、肝脏和鳃中观察到的水平较低。NF45的普遍表达与转录水平上假定的基因调控作用一致。用PHA刺激鱼类显著上调了大多数检测组织中NF45的表达，这可能表明NF45参与了PHA触发的免疫反应。
