疱疹病毒α-亚科部份成员gC等同膜糖蛋白的同源性及进化

HOMOLOGY AND EVOLUTION OF THE gC EQUIVALENT GLYCOPROTEINS OF SOME MEMBERS OF THE α-SUBFAMILY OF HERPES VIRUS

马疱疹病毒Ⅰ型属疱疹病毒α—亚科。本文分析了其膜糖蛋白g13基因的碱基序列,并由此推导其相应的氨基酸序列。同时利用电子计算机程序将g13与α—亚科的其它成员如伪狂犬病毒、水痘带状疱疹病毒和单纯疱疹病毒的相应膜糖蛋白进行比较,揭示了g13与伪狂犬病毒的g3、水痘带状疱疹病毒的gV和单纯疱疹病毒的gC同源,称为gC等同膜糖蛋白。这组膜糖蛋白都含有前导序列、跨膜疏水区域和天冬氨酸相关的糖基连结区。同时,这四种糖蛋白羟基端那一半的氨基酸序列高度保留,说明这一端具有重要的生物学功能;而氨基端那一半,除前导序列外,几乎找不出相似性。亚科中各病毒的寄主不同,各种糖蛋白在基因中的相应位置也不尽相同。同时,氨基酸序列的相似性较强,而碱基序列的相似性较弱。这一切表明,此亚科的病毒属同一起源而又经高度分化。

Equine Herpes Virus type-1 (EHV-I) belongs to the α-subfamily of Herpes Virus. The gene of the glycoprotein g13 of EHV- I was sequenced. Comparison of the putative amino acid sequence of g13 with the glycopro-teins of other members in this subfamily revealed that g13 of EHV-I is homologous to g3 of pseudorabies virus(PRV), gV of varicella-zoster virus ( VZV ) and gC of herpes simplex virus ( HSV ) . All of these glycopro-teins contain the signal sequence,the hydrophobic membrane spanning region and the N-X-S/T consensus sequences for N-linked glycosylation. The ho-mology of the amino acid sequences appeared at the carboxyl half of the proteins,indicating this part has important biological function. The dffer-ent location of these genes in the relative genomic map, the requiremnt for different specific host, the high homolgy of the amino acid sequencese and the low homology of the DNA sequence provide evidence that this subfamily originated from the same ancenstor and underwent much variation during evolution.