Nascimento Diana S, Pereira Pedro J B, Reis Marta I R, do Vale Ana, Zou Jun, Silva Manuel T, Secombes Christopher J, dos Santos Nuno M S
IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.
Fish Shellfish Immunol. 2007 Sep;23(3):701-10. doi: 10.1016/j.fsi.2007.02.003. Epub 2007 Feb 24.
In the search for pro-inflammatory genes in sea bass a TNF-alpha gene was cloned and sequenced. The sea bass TNF-alpha (sbTNF-alpha) putative protein conserves the TNF-alpha family signature, as well as the two cysteines usually involved in the formation of a disulfide bond. The mouse TNF-alpha Thr-Leu cleavage sequence and a potential transmembrane domain were also found, suggesting that sbTNF-alpha exists as two forms: a approximately 28 kDa membrane-bound form and a approximately 18.4 kDa soluble protein. The single copy sbTNF-alpha gene contains a four exon-three intron structure similar to other known TNF-alpha genes. Homology modeling of sbTNF-alpha is compatible with the trimeric quaternary architecture of its mammalian counterparts. SbTNF-alpha is constitutively expressed in several unstimulated tissues, and was not up-regulated in the spleen and head-kidney, in response to UV-killed Photobacterium damselae subsp. piscicida. However, an increase of sbTNF-alpha expression was detected in the head-kidney during an experimental infection using the same pathogen.
在寻找海鲈促炎基因的过程中，一个肿瘤坏死因子-α（TNF-α）基因被克隆并测序。海鲈TNF-α（sbTNF-α）推定蛋白保留了TNF-α家族的特征，以及通常参与二硫键形成的两个半胱氨酸。还发现了小鼠TNF-α的苏氨酸-亮氨酸切割序列和一个潜在的跨膜结构域，这表明sbTNF-α以两种形式存在：一种约28 kDa的膜结合形式和一种约18.4 kDa的可溶性蛋白。单拷贝的sbTNF-α基因包含一个四外显子-三内含子结构，与其他已知的TNF-α基因相似。sbTNF-α的同源建模与其哺乳动物对应物的三聚体四级结构相符。SbTNF-α在几种未受刺激的组织中组成性表达，在紫外线灭活的美人鱼发光杆菌杀鱼亚种刺激下，脾脏和头肾中的表达未上调。然而，在使用相同病原体进行的实验性感染过程中，在头肾中检测到sbTNF-α表达增加。
