关键词: 口蹄疫病毒, 受体, 牛αv基因, 克隆, 分子特征

Abstract: Foot-and-mouth disease virus（FMDV）has been showed to use four integrins, αvβ1, αvβ3, αvβ6 and αvβ8 as receptors to initiate infection. In this study, the bovine integrin αv gene was cloned from the lung tissue of healed cattle infected experimently with foot-and-mouth disease virus by RT-PCR, and compared the nucleotide and predicted amino acid sequence homology with the αv gene of other animals.The secondary structure of bovine αv protein was predicted by the biological softwares. The 3147bp cDNA of bovine integrin αv encodes a polypeptide of 1048 amino acids consisting of a 30-residue putative signal peptide, a 957-residue ectodomain, a 29-residue transmembrane domain, and a 32-residue cytoplasmic domain. The ectodomain contains 12 potential N-linked glycosylation sites（NXT/NXS）, 2 calcium binding domains(DX[D/N]XDGXXD), 18 cysteine residues, and a proteolytic cleavage site located between amino acid residue 890 and 891(KR-D). The nucleotide sequence similarity of integrin αv between cattle and rheses monkey, house mouse, dog, human,chicken is 91.0%,85.7%,90.1%,91.2%,73.1%, and the amino acid sequence similarity is 94.7%,91.6%,96.3%,95.0% and 81.6% respectively.The secondary structure of bovine αv contains few α-helix and many β-sheet and β-turn regions.The hydropathic analyses of the polypeptide revealed two hydrophobic domains,the signal peptide(1-30aa) and transmembrane domain(988-1017aa).

Key words: FMDV, receptor, bovine integrin αv cDNA, molecular characteristics