Processing of the Ebola virus glycoprotein by the proprotein convertase furin
Processing of the Ebola virus glycoprotein by the proprotein convertase furin
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DOI：
10.1073/pnas.95.10.5762
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发表时间：
1998-05-12
影响因子：
11.1
通讯作者：
Klenk, HD
中科院分区：
文献类型：
--
作者：
Volchkov, VE;Feldmann, H;Klenk, HD
在本研究中，我们研究了埃博拉病毒包膜糖蛋白（GP）的加工和成熟。当通过脉冲追踪实验分析痘苗病毒载体表达的 GP 时，鉴定出成熟形式和两种不同的前体。首先，检测到内质网形式 preGP(er)，即具有寡甘露糖苷 N-聚糖的全长 GP，preGP(er) (IIO kDa) 被高尔基体特异性形式 preGP (160 kDa)（含有成熟碳水化合物的全长 GP）取代，preGP 最终通过蛋白水解转化为成熟 GP(1,2)，其由两个二硫键连接的裂解产物（氨基末端）组成。 140 kDa 片段 GP(1) 和羧基末端 26 kDa 片段 GP(2)。 GP(1,2) 也在埃博拉病毒颗粒中被发现。采用定点诱变的研究表明，GP 在位于 ORF 位置 497 至 501 的多元氨基酸基序处被切割。切割被含有这样基序的肽基氯甲基酮阻断，CP被前蛋白转化酶弗林蛋白酶切割。观察结果表明，当弗林蛋白酶缺陷型 LoVo 细胞中表达 GP 时，不会发生裂解，但在这些细胞中，载体表达的弗林蛋白酶可恢复裂解。雷斯顿亚型与所有其他埃博拉病毒的不同之处在于其对人类的致病性较低，由于切割位点发生突变，其切割能力降低。根据这些观察结果，现在应该认为 GP 的蛋白水解加工可能是埃博拉病毒致病性的重要决定因素。
in the present study, we have investigated processing and maturation of the envelope glycoprotein (GP) of Ebola virus. When GP expressed from vaccinia virus vectors was analyzed by pulse-chase experiments, the mature form and two different precursors were identified. First, the endoplasmic reticulum form preGP(er), full length GP with oligomannosidic N-glycans, was detected, preGP(er) (IIO kDa) was replaced by the Golgi-specific form preGP (160 kDa), full-length GP containing mature carbohydrates, preGP was finally converted by proteolysis into mature GP(1,2), which consisted of two disulfide-linked cleavage products, the aminoterminal 140-kDa fragment GP(1), and the carboxyl-terminal 26-kDa fragment GP(2). GP(1,2) was also identified in Ebola virions. Studies employing site-directed mutagenesis revealed that GP was cleaved at a multibasic amino acid motif located at positions 497 to 501 of the ORF. Cleavage was blocked by a peptidyl chloromethylketone containing such a motif, CP is cleaved by the proprotein convertase furin. This was indicated by the observation that cleavage did not occur when GP was expressed in furin-defective LoVo cells but that it was restored in these cells by vector-expressed furin. The Reston subtype, which differs from all other Ebola viruses by its low human pathogenicity, has a reduced cleavability due to a mutation at the cleavage site. As a result of these observations, it should now be considered that proteolytic processing of GP may be an important determinant for the pathogenicity of Ebola virus.