首次从FMDV试验感染康复猪的舌皮和肺组织中克隆到了整联蛋白β1亚基的基因并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。猪整联蛋白β1亚基基因的编码区含有2 397个核苷酸, 编码798个氨基酸残基, 含有10个潜在的糖基化位点(NXTX/NXSX), 2个表皮生长因子相似结构域和3个半胱氨酸丰富区。其信号肽由20个氨基酸组成, 胞外域由708个氨基酸组成, 跨膜区由29个氨基酸组成, 胞浆域由41个氨基酸组成。猪β1基因与牛、猩猩、猫、犬、人、小鼠和鸡的β1基因的核苷酸序列一致性分别为99.5%, 90.0%, 91.8%, 90.7%, 90.2%, 86.5%和77.4%, 推导的氨基酸序列一致性分别为99.9%, 93.9%, 97.5%, 96.7%, 94.2%, 92.4%和94.9%。通过生物学软件分析发现β1亚基形成复杂的二、三级结构, 其中1~20位、729~757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。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了基础。
In this study, we first molecularly cloned pig integrin β1 from RNA of the tongue and lung of recovered pig infected experunentally with foot-and-mouth-disease virus(FMDV), and compared with the β1 gene of other animals available in GenBank at nucleotide and amino acid loves. The 2397 bp cDNA of pig irnegrln β1 encodes a polypeptide of 798 amino acids consisting of 10 potential N-linked glycosylation sites(NXTX/NXSX), 2 EGF-like domains and 3 cys-teine-rich regions. Pig integnin β1 aubunit has a 20-residue putative signal peptide, a 708-residue ectodomain, a 29-residue transmembrane domain, and a 41-residue cytoplasmic domain.The nucleotide sequence similarity of integrin βl between bovine, chimpanzee, cat, dog, human, mouse, chicken is 99.5%, 90.0%, 91.8%, 90.7%, 90.2%, 86.5% and 77.4%, and the amino acid sequence similarity is 99.9%, 93.9%, 97.5%, 96.7%, 94.2%, 92.4% and 94. 9% respectively.Hydrophobicity analysis of the polypepticle revealed two hydrophobic domains, the signal peptide(1-20AA)and transmembrane domain(729-757AA).This study will lay a foundation for understarxling the interactions of FMDV with recptors.
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