河豚白介素2基因鉴定及其生物信息学分析

Identification and characterization of an interleukin-2 homologue in fugu,Fugu rubripes,based on comparative genomics.

利用比较基因纽学方法，在河豚（Fugu rubripes）基因组中鉴定了IL-2基因（FrIL-2）．该基因为单拷贝基因，其结构、染色体定位均和人等高等动物一致，但基因非常精简，基因上游调控区含众多转录因子结合位点，3tUTR含poly（A）加尾信号和8个细胞因子类普遍存在的转录不稳定序列；FrIL-2基因编码149个氨基酸，N端含22个氨基酸组成的信号肽，肽链内含8个Cys，其中和生物学活性相关的Cys-66和Cys-116高度保守，在结构上存在一个类似IL-2特征性功能域结构，此外还存在一些修饰位点如N-糖基化位点和N端酰基化位点，比较河豚与人、哺乳动物、鸟类等IL-2的同源性，其氨基酸序列相似性为25％～34％，研究结果为今后利用鱼类基因组数据库和生物信息学快速鉴定新的鱼类功能基因打下了方法学基础．也为进一步开展鱼类IL-2基因功能研究提供了科学依据。

Using comparative genomies approach, an interleukin 2 （IL-2） homologue was identified from the puffer fish（Fugu rubripes）. The Fugu II. 2（FrIL-2） gene is a single copy gene encoding a precusor containing a 22 amino acid signal peptide and a I27 amino acid mature peptide. It shares the same gene organization and gene location with the mammalian IL-2 genes. FrIL-2 gene is quite compact as compared with mammalian IL-2 genes. 5＇ upstream region of the FrIL-2 includes several potential transcription factor binding sites while the 3＇-downstream region contains 8 mRNA instability motifs and 1 polyA signal. The deduced protein sequence shares only 25%～34% homology with mammalian and chicken IL-2s. The protein contains 8 eysteines while two of them（Cys-66 and Cys 116）are highly conserved. Besides, FrlL-2 has a structure which is similar to IL-2 functional domain and contains several potential phosphorylation sites, such as N-myristoylation site and N-glycosylation site. This report provided a quick method to identify new functional genes of fish through utilizing fish genomic databases and bioinformaties.