A New Ebola Virus Nonstructural Glycoprotein Expressed through RNA Editing
A New Ebola Virus Nonstructural Glycoprotein Expressed through RNA Editing
复制标题
DOI：
10.1128/jvi.02190-10
复制
发表时间：
2011-06-01
影响因子：
5.4
通讯作者：
Feldmann, Heinz
中科院分区：
文献类型：
--
作者：
Mehedi, Masfique;Falzarano, Darryl;Feldmann, Heinz
埃博拉病毒(EBOV)是一种包膜、单链、负义RNA病毒，可在人类和非人类灵长类动物中引起严重出血热。EBOV糖蛋白(GP)基因编码非结构可溶性糖蛋白(SGP)，但也通过转录编辑产生跨膜糖蛋白(GP(1，2))。第三种gp基因产物，一种小的可溶性糖蛋白(Ssgp)，长期以来一直被认为也是转录编辑的结果。为了鉴定和表征这种新的EBOV蛋白的表达，我们首先分析了在体外(在Vero E6细胞或Huh7细胞中)和在体内(在小鼠中)感染过程中产生的GP基因衍生转录物的相对比例。编码sgp、gp(1，2)和ssgp的转录本的平均百分比分别约为70%、25%和5%，表明ssgp转录本确实是通过转录编辑产生的。由于N端序列与Sgp相似，缺乏特异性抗体，且Sgp含量丰富，因此很难通过常规方法鉴定ssgp。优化的双向凝胶电泳法最终验证了在EBOV感染过程中组织培养中ssGP的表达和分泌。重组ssGP的生化分析表明，该蛋白为二硫键连接的同源二聚体，完全是N糖基化的。总之，我们已经鉴定并鉴定了一种新的EBOV非结构糖蛋白，它是通过对GP基因的转录编辑而表达的。虽然SSGP似乎与SGP具有相似的结构特性，但它对内皮细胞的抗炎功能似乎不同于SGP。
Ebola virus (EBOV), an enveloped, single-stranded, negative-sense RNA virus, causes severe hemorrhagic fever in humans and nonhuman primates. The EBOV glycoprotein (GP) gene encodes the nonstructural soluble glycoprotein (sGP) but also produces the transmembrane glycoprotein (GP(1,2)) through transcriptional editing. A third GP gene product, a small soluble glycoprotein (ssGP), has long been postulated to be produced also as a result of transcriptional editing. To identify and characterize the expression of this new EBOV protein, we first analyzed the relative ratio of GP gene-derived transcripts produced during infection in vitro (in Vero E6 cells or Huh7 cells) and in vivo (in mice). The average percentages of transcripts encoding sGP, GP(1,2), and ssGP were approximately 70, 25, and 5%, respectively, indicating that ssGP transcripts are indeed produced via transcriptional editing. N-terminal sequence similarity with sGP, the absence of distinguishing antibodies, and the abundance of sGP made it difficult to identify ssGP through conventional methodology. Optimized 2-dimensional (2D) gel electrophoresis analyses finally verified the expression and secretion of ssGP in tissue culture during EBOV infection. Biochemical analysis of recombinant ssGP characterized this protein as a disulfide-linked homodimer that was exclusively N glycosylated. In conclusion, we have identified and characterized a new EBOV nonstructural glycoprotein, which is expressed as a result of transcriptional editing of the GP gene. While ssGP appears to share similar structural properties with sGP, it does not appear to have the same anti-inflammatory function on endothelial cells as sGP.