Selective Degradation of mRNA by Herpes Simplex Virus 1

单纯疱疹病毒 1 对 mRNA 的选择性降解

• 批准号: 6952902
• 负责人: Bernard Roizman
• 金额: $ 30.27万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-10 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6952902
• 关键词: chemical stability; gene expression; genetic regulation; herpes simplex virus 1; host organism interaction; immediate early protein; laboratory mouse; messenger RNA; microbiology; nucleic acid sequence; protein structure function; reporter genes; virus RNA; virus protein

DESCRIPTION (provided by applicant): A prevailing view is that the HSV-1 UL41 tegument protein mediates nonspecific degradation of both viral and cellular mRNAs by cleavage of the RNA at or near the 5' terminus and that viral gene expression prevails because of a higher rate of transcription of viral genes. Our studies that form the basis of this grant application challenge several aspects of this view. Specifically: (i) Microarray analyses revealed the up regulation of several hundred genes in infected cells as compared to mock-infected cells. Validation studies (Northern analyses, Real-Time PCR and immunoblots) revealed 4 groups of mRNAs. Group 1 exemplified by IEX-1, c-fos, cox-2 and Ikappabalpha mRNAs were indeed up regulated but the protein products were not made. These mRNAs were degraded in a UL41 dependent manner by deadenylation, endonucleolytic cleavage and 3' to 5' processive degradation. Moreover, the 5' domains of the partially degraded mRNAs tended to linger and were readily detected in cytoplasmic extracts. Group 2 exemplified by tristetraprolin (TTP) mRNA and group 3 exemplified by GADD45beta mRNA were also up regulated but were stable and indeed translated, again all in a UL41 dependent manner!! Actin mRNA, abundant but not up regulated was rapidly degraded. The RNAs forming groups 2 and 3 contain A-U rich elements characteristic of rapidly turning over mRNAs whereas actin and GADD45beta mRNAs do not have these elements. TTP is a stress-related protein involved in the degradation of A-U rich mRNAs by binding and translocating these mRNAs to exosomes. In essence, the degradation of mRNA mediated by the UL41 protein is not indiscriminant but highly selective. This application has 4 aims i.e.(1) To identify the sequences in TTP mRNA that confer selective stability to the mRNA in wild-type virus infected cells;.(2) To define the mechanism by which the TTP mRNA is spared from degradation in wild-type virus infected cells.(3) To define the basis for the differential rates of degradation of mRNAs containing A-U rich elements in wild-type virus infected cells as compared to uninfected cells or cells infected with ?UL41 mutant virus, and (4) to determine whether the numerous functions now associated with the UL41 protein are co-variant and the role of these functions in the biology of HSV-1.

描述（由申请人提供）：一种流行的观点是，HSV-1 UL41 TEGUMENT蛋白介导了通过在5'末端或附近的RNA裂解病毒和细胞mRNA的非特异性降解，并且由于病毒基因的转录率较高，因此病毒基因表达的率较高。我们的研究构成了本赠款申请的基础，挑战了这种观点的几个方面。具体：（i）微阵列分析揭示了与模拟感染的细胞相比，受感染细胞中数百个基因的调节。验证研究（北方分析，实时PCR和免疫印迹）揭示了4组mRNA。 IEX-1，C-FOS，COX-2和IKAPPABALPHA mRNA的第1组确实受到了调节，但未制成蛋白质产物。这些mRNA通过deadenylation，deadenylation，内核酸裂解和3'至5'的过程降解以UL41依赖性方式降解。此外，部分降解的mRNA的5'结构域倾向于流连忘返，并在细胞质提取物中很容易检测到。第2组用三翼酚蛋白（TTP）mRNA示例和由GADD45Beta mRNA举例说明的组也受到了调节，但稳定且确实是翻译的，又以UL41依赖性方式进行了调节！ 肌动蛋白mRNA，丰富但不调节的mRNA迅速降解。 RNA组成2和3组包含迅速翻转mRNA的A-U丰富元素，而肌动蛋白和GADD45BETA mRNA没有这些元素。 TTP是一种与应激相关的蛋白质，通过结合和将这些mRNA易位到外泌体，参与A-U富mRNA的降解。本质上，UL41蛋白介导的mRNA的降解不是不差异的，而是高度选择性的。该应用具有4个目的，即（1）确定TTP mRNA中赋予对野生型病毒感染细胞mRNA的选择性稳定性的序列；（2）定义了TTP mRNA幸免于从野生型病毒感染细胞中降解的机制。与未感染的细胞或感染？UL41突变病毒的细胞或细胞相比，野生型病毒感染细胞，（4）确定现在与UL41蛋白相关的众多功能是否共同变化，并且这些功能在HSV-1的生物学中的作用。