Co-ordinate regulation of herpes simplex virus gene expression is mediated by the functional interaction of two immediate early gene products.
Co-ordinate regulation of herpes simplex virus gene expression is mediated by the functional interaction of two immediate early gene products.
复制标题
单纯疱疹病毒基因表达的协调调节是由两个早期基因产物的功能相互作用介导的。
DOI：
10.1016/0022-2836(86)90135-x
复制
发表时间：
1986
影响因子：
5.6
通讯作者：
Silverstein,S
中科院分区：
文献类型：
--
作者：
Gelman,IH;Silverstein,S
在单纯疱疹病毒感染后的早期，β启动子的转录仅在存在功能性174，000 Mr磷蛋白（ICP 4）的情况下启动，该蛋白由立即早期（α）基因（IE 4）编码。使用瞬时表达测定来分析在模型α和β基因启动子的转录调节中对五种α基因产物中的两种（ICP 4和ICP 0）的需要。这些研究表明，用含有感染细胞蛋白（ICP）4和0的α基因序列和胸苷激酶的质粒共转染细胞，（TK，β-基因）基因或与氯霉素乙酰转移酶（CAT）盒融合的胸苷激酶启动子比用编码α-基因或胸苷激酶启动子的质粒共转染的细胞积累10至20倍的RNA或显示10至20倍的CAT活性。基因蛋白和胸苷激酶指示基因。在瞬时表达测定系统中，功能性ICP 4是增强转录激活所必需的。如转染细胞的免疫荧光染色分析所示，ICP 0均匀分散在整个细胞核中也是必需的。使用两种α启动子-CAT融合物作为靶标，研究ICP 4、ICP 0和Vmw 65（病毒体相关α基因反式激活因子）对α启动子表达的影响，所述α启动子包含赋予α基因调控的所有序列，或仅包含控制基础水平表达的核心序列。我们的结论是，ICP 4可以激活核心序列的α基因表达，并根据其丰度，激活或抑制含有α基因调控所需序列的启动子的表达。与这些α-调控序列无关，低水平编码ICP 0和ICP 4的序列共转染激活表达。在较高的效应物比率（ICP 4和ICP 0两者）下，CAT活性的靶累积降低。虽然IE 4（从突变病毒tsK克隆）的atsallele不激活α基因表达，但它可以增强ICP 0激活含有α调节序列的靶标的能力。涉及tsK的病毒研究支持这样的结论，即功能性ICP 4是激活β启动子和抑制α启动子表达所必需的，并有助于解释tsK突变的多效性效应。这些分析还揭示了一种新的RNA种类的存在，其与编码ICP 0的序列重叠。我们的研究结果表明，HSV基因表达的协调调节是由至少两个α基因产物ICP 0和ICP 4的功能相互作用介导的。
At early times after infection with herpes simplex virus, transcription from β-promoters is initiated only in the presence of a functional 174,000Mrphosphoprotein (ICP4), encoded by an immediate early (α) gene (IE4). A transient expression assay was used to analyze the requirement for two (ICP4 and ICP0) of the five α-gene products in the transcriptional regulation of model α and β-gene promoters. These studies reveal that cells cotransfected with plasmids containing the α-gene sequences for infected cell proteins (ICPs) 4 and 0 and a thymidine kinase (TK, a β-gene) gene or the thymidine kinase promoter fused to a chloramphenicol acetyltransferase (CAT) cassette accumulate 10 to 20-fold more RNA or exhibit 10 to 20-fold more CAT activity than cells cotransfected with a plasmid encoding either α-gene protein and a thymidine kinase indicator gene. Functional ICP4 is required for enhanced transcriptional activation in the transient expression assay system. It is also required for the uniform dispersal of ICP0 throughout the nucleus as shown by immunofluorescence staining analysis of transfected cells. Two α-promoter-CAT fusions were used as targets to study what effects ICP4, ICP0 and Vmw65 (the virion-associated α-gene transactivator) have on expression from α-promoters that contain all of the sequences that confer α-gene regulation, or only the core sequence governing basal level expression. We conclude that ICP4 can activate α-gene expression from the core sequence and, depending on its abundance, activate or repress expression from a promoter containing the sequences required for α-gene regulation. Independent of these α-regulatory sequences cotransfection with low levels of sequences encoding both ICP0 and ICP4 activate expression. At higher ratios of effector (both ICP4 and ICP0) the target accumulation of CAT activity decreases. Although atsallele of IE4 (cloned from the mutant virus tsK) does not activate α-gene expression it can enhance the ability of ICP0 to activate a target containing α-regulatory sequences. Virus studies involving tsK support the conclusion that functional ICP4 is required to activate β-promoters and to repress expression from α-promoters and help to explain the pleiotropic effects of the tsK mutation. These analyses have also revealed the presence of a novel RNA species that overlaps the sequences encoding ICP0. Our results suggest that co-ordinate regulation of HSV gene expression is mediated by the functional interaction of at least two α-gene products, ICP0 and ICP4.