Role of the C-terminal RDEL motif of the myxoma virus M-T4 protein in terms of apoptosis regulation and viral pathogenesis
Role of the C-terminal RDEL motif of the myxoma virus M-T4 protein in terms of apoptosis regulation and viral pathogenesis
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DOI：
10.1006/viro.1999.9946
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发表时间：
1999-10-25
期刊：
影响因子：
3.7
通讯作者：
McFadden, G
中科院分区：
文献类型：
--
作者：
Hnatick, S;Barry, M;McFadden, G
本研究的目的是探讨粘液瘤病毒M-T4蛋白的末端RDEL基序在细胞凋亡调控和病毒毒力率方面的意义。为了实现这一点，创建了重组粘液瘤病毒，其中M-T4的C-末端RDEL基序被删除，并在紧下游插入选择性标记（Ecogpt）。我们假设从M-T4中去除RDEL基序将改变蛋白质的亚细胞定位，并提供对其抗凋亡作用的深入了解。令人惊讶的是，从M-T4中去除RDEL基序并不影响内质网（ER）内蛋白质的定位，但它确实降低了突变蛋白的稳定性。脉冲追踪免疫沉淀和内切糖苷酶H分析结合共聚焦荧光显微镜证实，M-T4 RDEL（-）突变蛋白保留在ER样野生型M-T4中，并表明C-末端RDEL基序不是M-T4定位于ER的唯一决定因素。与野生型和M-T4基因敲除突变病毒相比，M-T4 RDEL（-）突变病毒感染培养的兔淋巴细胞导致中间凋亡表型。当用重组M-T4 RDEL（-）突变病毒感染欧洲兔时，观察到一种新的粘液瘤病表型。在感染后第9天感染M-T4 RDEL（-）病毒的家兔在继发感染部位（特别是耳部）表现出加重的水肿和炎症反应。我们的研究结果表明，C-末端RDEL基序可能不是唯一负责M-T4保留到ER的，M-T4可能具有双重功能，即保护感染的淋巴细胞免于凋亡和调节对病毒感染的炎症反应。(C)北京：科学出版社.
The purpose of this study was to investigate the significance of the terminal RDEL motif of the myxoma virus M-T4 protein in terms of apoptosis regulation and rate in viral virulence. To accomplish this, a recombinant myxoma virus was created in which the C-terminal RDEL motif of M-T4 was deleted and a selectable marker (Ecogpt) was inserted immediately downstream. We hypothesized that removal of the RDEL motif from M-T4 would alter the subcellular localization of the protein and provide insight into its antiapoptotic role. Surprisingly, removal of the RDEL motif from M-T4 did not affect localization of the protein within the endoplasmic reticulum (ER), but it did reduce the stability of the mutant protein. Pulse-chase immunoprecipitation and endoglycosidase H analysis coupled with confocal fluorescent light microscopy demonstrated that the M-T4 RDEL(-) mutant protein is retained in the ER like wildtype M-T4 and suggests that the C-terminal RDEL motif is not the sole determinant for M-T4 localization to the ER. Infection of cultured rabbit lymphocytes with the M-T4 RDEL(-) mutant virus results in an intermediate apoptosis phenotype compared with the wildtype and M-T4 knockout mutant viruses, A novel myxomatosis phenotype was observed in European rabbits when infected with the recombinant M-T4 RDEL(-) mutant virus. Rabbits infected with the M-T4 RDEL(-) virus on day 9 postinfection exhibited an exacerbated edematous and inflammatory response at secondary sites of infections, particularly the ears. Our results indicate that the C-terminal RDEL motif may not he solely responsible for retention of M-T4 to the ER and that M-T4 may have a dual function In protecting infected lymphocytes from apoptosis end in modulating the inflammatory response to virus infection. (C) 1999 Academic Press.