小反刍兽疫病毒受体SLAM基因的克隆及其结构与功能分析

信号淋巴激活分子（SLAM）为小反刍兽疫病毒（PPRV）感染其自然宿主的细胞受体。本试验从山羊外周血淋巴细胞中克隆获得了SLAM基因,并对其结构和功能的关系进行分析,为研究SLAM的功能及其在PPRV侵染过程中的作用奠定基础。利用RT-PCR的方法对山羊SLAM基因全长进行克隆,通过生物学软件对其核苷酸序列和氨基酸序列进行了比对,利用Swiss-Model进行三级结构预测,然后分析其结构和功能之间的关系。山羊、绵羊、黄牛、水牛、虎鲸和海豚SLAM基因同源性较高,分别是98.7%、96.6%、96.3%、89%和88.8%,氨基酸的相似性分别是97.6%、94.1%、93.2%、83.5%和83.6%。山羊SLAM蛋白V结构域中存在8个影响宿主—病毒特异性结合的8个关键氨基酸,且与绵羊、黄牛和水牛的均完全保守;胞内区含有三段高度保守的富含酪氨基酸（Tyrosine）的基序（TXXYXXV/I/A）。本试验成功地克隆小反刍兽疫病毒受体SLAM基因,分析和预测了SLAM蛋白的结构和功能的关系,为其进一步的生物学功能研究及其应用奠定了基础。

Cloning of the SLAM gene of peste des petits ruminants virus receptor and analysis of its structure and function

Signaling lymphocyte activation molecule （SLAM） is one of the cellular receptors for peste des petits ruminants virus （PPRV） infection. The objective of the present study was to clone the gene of caprine SLAM and analyze the structure-function relationship of SLAM protein. The caprine SLAM gene was cloned by RT-PCR,in addition, the nucleotide and amino acid sequences were analyzed and compared with natural hosts for other members of Morbillivirus through bioinformatics methods, and the protein tertiary structure was predicted using Swiss- Model. Sequence analysis showed that the homologies of nucleotide sequences between goat and sheep,cattle, water buffalo, killer whale and dolphin were 98. 7%, 96. 6%, 96. 3%, 89% and 88.8%,respectively, and the homologies of the deduced amino acid sequences were 97. 6%, 94.1% ,93.2% ,83.5% and 83.6% ,respectively. There were 8 amino acid residues in the V region of caprine SLAM,which were thought to be involved in determining host-virus specificity and be completely conserved with sheep, cattle and water buffalo. There were three conserved leucine- rich motifs （TXXYXXV/I/A） in cytoplasmic domain. The caprine SLAM gene was successfully cloned. Furthermore,the structure and function of this gene were analyzed and predicted.