蕨麻猪白细胞抗原Ⅰ类分子3基因的克隆和序列分析

Cloning and sequence analysis of Juema swine lymphocyte antigen-3 gene

参照GenBank上登录的猪SLA-3基因序列(GenBank登录号:AF464010)设计1对引物,从经ConA刺激的蕨麻猪外周血液淋巴细胞中提取RNA,进行克隆、测序以及同源性分析和蛋白结构预测分析.结果表明:克隆的蕨麻猪SLA-3基因大小为1 086 bp,含一个完整的开放阅读框,编码361个氨基酸,还含有一段21个氨基酸的信号肽序列;核苷酸序列与GenBank上登录的SLA-3参考序列的同源性为93.1%;与牛、绵羊、山羊的同源性较高,而与鸡的同源性最低.蛋白分子结构预测表明,猪SLA-3基因编码的蛋白分子是由胞外区(303个氨基酸)、跨膜区(23个氨基酸)和胞内区(35个氨基酸)组成的一种跨膜蛋白.

Swine lymphocyte antigen-3 （SLA-3） gene was cloned by reverse transcription-polymerase chain reaction （RT-PCR） from peripheralblood lymphocyte stimulated by ConA in Juema swine. The sequence analysis showed that the SLA-3 gene was 1 086 bp in length and encoded 361 amino acids which was about 40 KD with 36 strongly basic（＋） amino acids, 44 strongly acidic（-） amino acids, 110 hydrophobic amino acids and 102 polar amino acids,including a signal peptide of 21 amino acids. The similarity of nucleotide sequence of porcine SLA-3 to the published （AF464010） was up to 93. 1%. The homology of nucleotide sequence of SLA-3 to those of Bos taurus ,Ovis aries ,Capra hircus was much higher than as of Homo sapiens Pongo,G. gorilla, Pan troglodytes, Equus caballus, Felis catus and the lowest was that of Gallus gallus. The protein structure prediction demonstrated that the SLA-3 was a transmembrane protein composed of extracellular domain, transmembrane domain and intracellular domain.