The vaccinia virus E8R gene product is required for formation of transcriptionally active virions
The vaccinia virus E8R gene product is required for formation of transcriptionally active virions
复制标题
DOI：
10.1016/j.virol.2007.05.002
复制
发表时间：
2007-10-25
期刊：
影响因子：
3.7
通讯作者：
Moussatche, Nissin
中科院分区：
文献类型：
--
作者：
Kato, Sayuri E. M.;Condit, Richard C.;Moussatche, Nissin
两个痘苗病毒温度敏感突变体被定位在E8R基因上，并进行了表型分析。Dts23在E8R(L81F)的编码区存在错义突变，CTS 19的起始蛋氨酸密码子由ATG变为ATA(M11)。这两个IS突变体在感染过程中表现出基因表达和DNA复制的正常模式。E8蛋白在感染后期专门合成并包装成病毒核心。Western印迹分析表明，在允许(31摄氏度)和非允许温度(39.7摄氏度)下，感染Dts23的细胞E8合成减少，在这两种条件下Cts19感染都没有E8合成。在39.7℃下产生的dts23病毒粒子在外观上与wt病毒粒子难以区分。CTS19在39.7℃下孵育时不能产生可识别的病毒结构；在39.7℃下产生的纯化的Dts23病毒粒子含有减少的E8，并具有高的颗粒与感染性比率；在31℃下生长的纯化的CTS 19病毒粒子也显示出降低的传染性，不含可检测到的E8。在39.7℃下生长的Dts23可以进入细胞，但不能合成早期mRNA或产生CPE。突变病毒粒子的可溶性提取物在依赖启动子的体外转录实验中是有效的，而完整的突变核心在转录方面是有缺陷的。我们认为E8在病毒核心结构中起着微妙的作用，直接或间接地影响核心转录。由爱思唯尔公司出版。
Two vaccinia virus temperature-sensitive mutants were mapped to the E8R gene and subjected to phenotypic characterization. Dts23 contains a missense mutation in the coding region of E8R (L81F), and in Cts 19 the initiating methionine codon is changed from ATG to ATA(M11). The two is mutants display normal patterns of gene expression and DNA replication during infection. The E8 protein is synthesized exclusively late during infection and packaged into virion cores Western blot analysis revealed that E8 synthesis is reduced in Dts23 infected cells at permissive (31 degrees C) and non-permissive temperature (39.7 degrees C) and absent in Cts19 infection under both conditions. Dts23 virions produced at 39.7 'C were indistinguishable in appearance from wt virions. Cts19 fails to produce identifiable viral structures when incubated at 39.7 degrees C. Purified Dts23 virions produced at 3 9.7 degrees C contain reduced amounts of E8 and have a high particle to infectivity ratio; purified Cts 19 virions grown at 31 degrees C also show reduced infectivity and do not contain detectable E8. Dts23 grown at 39.7 degrees C could enter cells but failed to synthesize early mRNA or produce CPE. Soluble extracts from mutant virions were active in a promoter dependent in vitro transcription assay, however intact mutant cores were defective in transcription. We suggest that E8 plays a subtle role in virion core structure that impacts directly or indirectly on core transcription. Published by Elsevier Inc.