Mechanisms of ERK activation in gammaherpesvirus

描述(申请人提供)：卡波西肉瘤相关疱疹病毒(KSHV)是三种人类恶性肿瘤的病原体，包括卡波西肉瘤(KS)，这是世界上最常见的与艾滋病相关的肿瘤。虽然HAART疗法的广泛使用导致美国KS病例数量下降，但在艾滋病流行仍在继续的发展中国家，KS发病率上升。这项研究的长期目标是扩大我们对伽马疱疹病毒的基本生物学的理解，包括结构、组装和病毒与宿主细胞的相互作用。随着最近在与KSHV同源的RRV纯化病毒粒子中发现ERK1/2，我们开始推测这一途径在病毒感染中的重要性。我们推测，这些酶的掺入可能代表了病毒感染期间细胞环境的快照，反映了在病毒复制和组装附近高度活跃的细胞途径，并可能在病毒生产过程中发挥重要作用。为了检验这一假说，本文提出了两个具体目标。第一个目的是确定ERK1/2掺入的结构方面。我们将在生物化学上确认质谱学数据，同时还将确定这些物种在颗粒中的结构定位、物种特异性和大致丰度。二是明确RRV与MEK/ERK途径在新发感染过程中的相互作用。我们将确定ERK激活的动力学，以及定义晚期激活的机制。通过使用病毒DNA复制抑制剂以及全局转录和翻译抑制剂，我们将评估潜在的病毒基因(S)和细胞过程在轮状病毒感染过程中激活ERK的作用。与公众健康相关：病毒与宿主一起进化，找到了操纵细胞环境的方法来造福于它们。该项目旨在深入了解伽马疱疹病毒在病毒感染过程中如何与MEK/ERK途径相互作用和使用。由于艾滋病患者免疫系统的减弱，KS的治疗往往是有限的；然而，我们的研究可能确定病毒和癌细胞特异性标记物，可能成为KS的靶向治疗。这种方法可能使我们能够干扰感染和随后的疾病进展，即使在没有健康的免疫系统的情况下也是如此。

DESCRIPTION (provided by applicant): Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of three human malignancies, including Kaposi's sarcoma (KS), the most common AIDS-related neoplasm worldwide. While the widespread use of HAART therapy has resulted in a decline in the number of KS cases in the US, KS incidence has increased in developing countries where the AIDS epidemic continues. The long-term objective of this study is to broaden our understanding of the basic biology of gammaherpesviruses, including structure, assembly, and virus-host cell interactions. With the recent finding of ERK1/2 within the purified virion of Rhesus monkey rhadinovirus (RRV), a close homolog of KSHV, we began to speculate the importance of this pathway in viral infection. We hypothesize that the incorporation of these enzymes may represent a snapshot of the cellular environment during viral infection, reflecting a cellular pathway that is highly active in the vicinity of viral replication and assembly and that may play important roles during virus production. Two specific aims are proposed to test this hypothesis. The first is designed to determine the structural aspect of ERK1/2 incorporation. We will biochemically confirm mass spectrometry data, while also determining structural localization, species-specificity, and approximate abundance of these species within the particle. The second is to define the interaction between RRV and the MEK/ERK pathway during de novo infection. We will determine the kinetics of ERK activation, as well as define a mechanism for late phase activation. With the use of viral DNA replication inhibitors, as well as global transcription and translation inhibitors, we will assess role of potential viral gene (s) and cellular processes in activating ERK during RRV infection. Relevance to public health: Viruses, having evolved with the host, have found ways to manipulate the cellular environment for their benefit. This project is designed to provide insight into how gammaherpesviruses interact with and use the MEK/ERK pathway during viral infection. Due to the weakened immune system of AIDS patients, KS treatment is often limited; however, our studies may identify virus and cancer cell specific markers that may become targeted therapies for KS. This approach may enable us to interfere with infection and subsequent disease progression, even in the absence of a healthy immune system.