Faccini A M, Cairney M, Ashrafi G H, Finbow M E, Campo M S, Pitts J D
Beatson Laboratories, Beatson Institute for Cancer Research, Bearsden, Glasgow, United Kingdom.
J Virol. 1996 Dec;70(12):9041-5. doi: 10.1128/JVI.70.12.9041-9045.1996.
The E8 open reading frame of bovine papillomavirus type 4 encodes a small hydrophobic polypeptide which contributes to cell transformation by conferring anchorage-independent growth. Using an in vitro translation system, we show that the E8 polypeptide binds to ductin, the 16-kDa proteolipid that forms transmembrane channels in both gap junctions and vacuolar H+-ATPase. This association is not due to nonspecific hydrophobic interactions. PPA1, a Saccharomyces cerevisiae polypeptide homologous (with 25% identity) to ductin, does not complex with E8. Furthermore, E5B, structurally similar to E8 but with no transforming activity, does not form a complex with ductin. Primary bovine fibroblasts expressing E8 show a loss of gap junctional intercellular communication, and it is suggested that this results from the interaction between E8 and ductin.
牛乳头瘤病毒4型的E8开放阅读框编码一种小的疏水性多肽,该多肽通过赋予不依赖贴壁生长的特性来促进细胞转化。利用体外翻译系统,我们发现E8多肽与导管蛋白结合,导管蛋白是一种16 kDa的蛋白脂质,在间隙连接和液泡H⁺-ATP酶中均形成跨膜通道。这种结合并非由于非特异性疏水相互作用。PPA1是一种与导管蛋白同源(具有25%的同一性)的酿酒酵母多肽,它不与E8形成复合物。此外,E5B在结构上与E8相似,但没有转化活性,它也不与导管蛋白形成复合物。表达E8的原代牛成纤维细胞显示间隙连接细胞间通讯丧失,提示这是E8与导管蛋白相互作用的结果。