中国生物工程杂志

Receptors play a crucial role in determining the host specificity and tissue tropism of virus. Foot-and-mouth disease virus（FMDV）has been showed to use four integrins, αvβ1, αvβ3, αvβ6 and αvβ8 as receptors to initiate infection and αvβ6 functions as the major receptor. In this study, we first cloned and sequenced the cDNA encoding bactrian camel integrin β6 from the lung tissue. The 2367bp cDNA of bactrian camel integrin β6 encodes a polypeptide of 788 amino acids consisting of a 26-residue putative signal peptide, a 681-residue ectodomain with 8 potential N-linked glycosylation sites and 58 cysteine residues, a 29-residue transmembrane domain, and a 52-residue cytoplasmic domain with a NPLY motif and 1 potential N-linked glycosylation site. The nucleotide sequence similarity of integrin β6 between bactrian camel and cattle, pig, sheep, human, mouse, Norway rat is 91.1%、91.8%、90.6%、90.5%、83.7%、84.1%, and the amino acid sequence similarity is 94.3%、93.4%、93.4%、93.7%、88.7%、88.6%, respectively. The bactrian camel β6 gene exhibited the higher sequence homology with the β6 gene of cattle, pig and sheep, indicating their close genetic relationships. It is possible that host tropism of FMDV may related to divergence in β6 receptors among different species.