猪口蹄疫病毒受体β3亚基的基因克隆与分子特征  

Molecular cloning and characteristics of cDNA porcine β3 subunit for FMDV receptor

作　　者：吕占禄[1] 王光祥[1] 尚佑军[1] 刘湘涛[1] 

机构地区：[1]中国农业科学院兰州兽医研究所家畜疫病病原生物学国家重点实验室国家口蹄疫参考实验室,兰州730046

出　　处：《中国人兽共患病学报》2012年第4期358-362,共5页Chinese Journal of Zoonoses

摘　　要：目的为研究β3亚基在口蹄疫感染过程中所扮演的角色,同时也为进一步深入研究FMDV嗜性、与宿主细胞的相互作用、病毒的侵入机制等问题奠定基础。方法从正常的猪肾细胞(pk15)中克隆到了整联蛋白β3亚基的基因,对其核苷酸序列和推导的氨基酸序列以及蛋白结构进行了分析并与真核表达载体pCDNA3.1(+)相连接。结果猪整联蛋白β3亚基基因的编码区含有2 355个核苷酸,编码785个氨基酸残基,其信号肽由22个氨基酸组成;胞外域由692个氨基酸组成,含有8个潜在的糖基化位点(NXS/NXT)和57个半胱氨酸(Cys)残基;跨膜区由29个氨基酸组成;胞浆域由41个氨基酸组成。猪β3基因与羊、人、马、犬、家鼠和挪威大鼠此基因核苷酸序列的同源性分别为94.3%、90.1%、92.1%、90.9%、86.1%、86.2%,推导氨基酸序列的同源性分别为95.0%、91.8%、92.5%、91.7%、88.8%、88.7%。结论通过生物学软件分析发现猪β3亚基形成复杂的2、3级结构,其中1-22位、715-743位氨基酸区段疏水性较强,分别是该亚基的信号肽和跨膜区,以及成功构建了β3亚基的重组真核表达载体pCDNA3.1(+)β3。Foot and mouth disease virus（FMDV） has been showed to use 4 integrins including αvβ1,αvβ3,αvβ6 and αvβ8 as receptors to initiate infection.The aim was to lay a foundation for understanding the interaction of FMDV with receptor.In this study,we firstly molecularly cloned pig integrin β3 from RNA of normal PK15 cell,and compared it with the β3 gene of other animals available in GenBank at nucleotide and amino acid levels.The digested and purified β3 gene of pig were cloned into eukaryotic expression vector pCDNA3.1（＋）.The 2,355 bp cDNA of porcine integrin β3 encoded a polypeptide of 785 amino acids consisting of a 22 residue putative signal peptide,a 692 residue ectodomain with 8 potential N-linked glycosylation sites and 57 cysteine residues,a 29 residue transmembrane domain,and a 41 residue cytoplasmic domain.The nucleotide sequence similarity of integrin β3 between pig and sheep,human,horse,dog,house mouse and Norway rat were 94.3%,90.1%,92.1%,90.9%,86.1% and 86.2%,and the amino acid sequence similarity were 95.0%,91.8%,92.5%,91.7%,88.8% and 88.7%,respectively.Hydrophobicity analysis of the polypeptide revealed 2 hydrophobic domains,the signal peptide（1-22aa）and transmembrane domain（715-743aa）.The eukaryotic expression recombinant plasmid pCDNA3.1（＋） β3 were successfully constructed.

关 键 词：口蹄疫病毒 受体 猪整联蛋白β3基因 分子特征 序列分析 

分 类 号：R378[医药卫生—病原生物学]