Control of translation in herpesvirus infected cells

描述（由申请人提供）：在翻译水平调节基因表达对于控制正常细胞生长、发育、分化、学习、记忆和对环境应激（包括病毒感染）的反应至关重要。特别是，许多真核生物加帽的多腺苷酸化mRNA的翻译在起始步骤受到控制，其中需要调节专门的多蛋白复合物的组装以将小核糖体亚基募集到mRNA 5'末端。该复合物的翻译起始因子组分能够响应不同的细胞信号级联，从而能够对不同的生理效应物做出快速响应。病毒模型系统已被证明是特别有用的阐述细胞翻译控制策略，因为它们的成功复制绝对需要病毒mRNA翻译。在病毒持续努力捕获和参与细胞蛋白质合成机制的过程中，病毒必须有效地控制调节翻译的细胞信号级联。这项调查利用疱疹病毒家族成员，人巨细胞病毒（HCMV），作为探针，探索复杂的电路调节mRNA翻译的启动。虽然在大多数健康个体中无害，但HCMV是一种广泛存在的机会性病原体，在免疫功能低下者中引起严重疾病，包括骨髓和实体器官移植受者以及艾滋病患者沿着。此外，先天性HCMV感染是新生儿出生缺陷的主要病毒原因。我们的长期总体目标是了解HCMV如何操纵细胞翻译控制途径，以确保病毒mRNA能够有效地与细胞mRNA竞争获得翻译起始因子。由于这一过程对于生产性复制和从潜伏期重新激活至关重要，我们的研究可能会揭示干扰病毒复制的新靶点和创建可用于疫苗开发的弱化减毒菌株的新策略。此外，这些研究将提供对翻译控制的基本机制的深入了解，这些机制可能在许多人类疾病中被证明是重要的，包括癌症和糖尿病，其中蛋白质产生的调节是异常的。我们特别提出i）确定HCMV感染如何影响eIF 4F-核心和相关组分; ii）定义HCMV感染细胞中PABP丰度被预防性控制的机制;和iii）评估细胞eIF 4 E-激酶和eIF 4 E磷酸化对病毒复制和发病机制的作用。细胞蛋白质的产生对于影响人类健康的许多重要生物过程至关重要，包括正常的细胞生长，发育，学习，记忆和对环境压力的适当反应。虽然蛋白质的产生受到高度调节，并对各种天然信号作出反应，但蛋白质产生的调节过程在许多人类疾病中被破坏，包括癌症，糖尿病和病毒感染，导致蛋白质产生的显著改变。为了了解蛋白质的产生是如何在细胞中有效调节的，我们的研究利用了人巨细胞病毒（HCMV）的力量来捕获，参与和操纵对正确控制蛋白质产生至关重要的复杂电路。全面了解蛋白质的产生是如何控制的，有助于制定治疗许多人类疾病的新策略，包括由HCMV引起的疾病，尽管HCMV对大多数健康个体无害，但在免疫系统功能不正常的个体（包括移植受者沿着艾滋病患者）中会导致严重疾病，并且是新生儿出生缺陷的主要病毒原因。

DESCRIPTION (provided by applicant): Regulation of gene expression at the level of translation is fundamentally important for the control of normal cell growth, development, differentiation, learning, memory, and the response to environmental stress, including viral infection. In particular, the translation of many eukaryotic capped, polyadenylated mRNAs is controlled at the initiation step, where the regulated assembly of a specialized, multiprotein complex is required to recruit the small ribosome subunit to the mRNA 5' terminus. The translation initiation factor components of this complex are capable of responding to different cellular signaling cascades, enabling a rapid response to diverse physiological effectors. Viral model systems have proven to be particularly useful in elaborating cellular translational control strategies because their successful replication absolutely requires viral mRNA translation. In their continued efforts to capture and engage the cellular protein synthesis machinery, viruses must effectively control the cellular signaling cascades that regulate translation. This investigation utilizes a herpesvirus family member, human cytomegalovirus (HCMV), as a probe to explore the complex circuitry regulating the initiation of mRNA translation. Although innocuous in most healthy individuals, HCMV is a widespread, opportunistic pathogen responsible for severe disease among the immunocompromised, including bone marrow and solid organ transplant recipients along with AIDS patients. In addition, congenital HCMV infection is the leading viral cause of birth defects in newborns. Our long-term overall objective is to understand how HCMV manipulates cellular translational control pathways to ensure that viral mRNAs can compete effectively with cellular mRNAs for access to translation initiation factors. As this process is critical for productive replication and reactivation from latency, our investigation is likely to reveal new targets for interfering with viral replication and new strategies for creating weakened, attenuated strains useful for vaccine development. In addition, these studies will provide insight into basic mechanisms of translational control that are likely to prove important in many human diseases, including cancer and diabetes, where the regulation of protein production is abnormal. We specifically propose to i) determine how HCMV infection affects eIF4F-core and associated components; ii) define the mechanism(s) by which PABP abundance is controlled translationally in HCMV-infected cells; and iii) evaluate the role of cellular eIF4E-kinases & eIF4E phosphorylation on viral replication & pathogenesis PUBLIC HEALTH RELEVANCE: Cellular protein production is critical for many important biological processes that impact upon human health including normal cell growth, development, learning, memory and proper response to environmental stress. While protein production is highly regulated and responsive to a variety of natural cues, the regulated process of protein production is disrupted in many human diseases, including cancer, diabetes, and viral infections, resulting in significant alterations in protein production. To understand how protein production is effectively regulated in cells, our studies exploit the power of human cytomegalovirus (HCMV) to capture, engage and manipulate the complex circuitry that is vital to properly control protein production. A comprehensive picture of how protein production is controlled could contribute to new strategies of treating many human diseases, including those caused by HCMV, which despite being innocuous in most healthy individuals, causes severe disease in individuals whose immune systems are not functioning properly (including transplant recipients along with AIDS patients) and is the leading viral cause of birth defects in newborns.