特超强毒648株马立克氏病病毒的囊膜糖蛋白gE基因的克隆和序列比较

鸡马立克氏病毒特超强毒 (vv+MDV) 648株的囊膜糖蛋白 gE基因经PCR扩增并克隆入pUC1 8载体。 648株gE基因经核酸序列分析测定 ,全长为 1 494碱基。所编码的蛋白具有跨膜糖蛋白的一些特征。它含有 8个潜在的糖基化位点、N端有一段疏水区 (1～ 1 9aa)所构成的信号肽、C端有一段疏水区 (391～ 41 9aa)所构成的膜锚着序列。经 648株 (vv+MDV)和马立克氏病毒强毒 (vMDV)GA株的 gE相比较 ,在MDV血清 1型中 gE是较为保守的 ,二者仅有 2个核苷酸的差异 (第 51 2位、第 1 472位 ) ,并导致了有二个相应的氨基酸的改变 (第1 71位Leu/Pro、第 491位Arg/Lys)。

THE CLONE AND COMPARISON OF VERY VIRULENT PLUS MAREK'S DISEASE VIRUS(vv + DMV) 648 STRAIN GLYCOPROTEIN E (gE) GENE

The glycoprotein E(gE) gene of very virulent plus Marek's Disease (vv+ MDV) 648 strain was amplified by polymerase chain reaction (PCR) and cloned into pUC18 vector. The gE sequence was determined and analysed. The whole length of 648 strain gE gene is 1494 base pairs. The protein encoded by gE gene has several features characteristic of a membrane-associated glycoprotein. It contains eight potential glycosylation sites, a markedly hydrophobic region at the N terminus that could function as a signal peptide and a hydrophobic segment (aa 391-419) at C terminus that could function as a transmembrane anchor element. Comparison of the gE between 648 strain and virulent MDV (vMDV) GA strain revealed that gE sequence is conserved in MDV serotype 1, there are only two basepairs different, (at bp 512 and 1472), which induce two amino acids changed respectively (at aa 171 and 491). The function of 648 strain gE and the difference of gE between 648 strain and GA strain is on study.