HCMV US28 Signal Transduction by Betaarrestin proteins

Betaarrestin 蛋白的 HCMV US28 信号转导

• 批准号: 6987737
• 负责人: WILLIAM E MILLER
• 金额: $ 22.83万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6987737
• 关键词: Herpes simplex disease; arrestins; biological signal transduction; cell line; cell migration; cell surface receptors; cytomegalovirus; gene mutation; gene targeting; genetic regulation; host organism interaction; immunomodulators; intermolecular interaction; muscle cells; opportunistic infections; pathologic process; phosphorylation; protein structure function; receptor expression; receptor sensitivity; smooth muscle; virus genetics

DESCRIPTION (provided by applicant): Human Cytomegalovirus (HCMV) infection is a leading cause of viral associated congenital birth defects and has proven to be a significant public health problem in organ transplant recipients as well as in individuals with AIDS. Accumulating evidence indicates that there may be a relationship between HCMV and the development of vascular disease. The interplay between HCMV and the immune system is a critical factor in the events leading to initiation of disease. Interestingly, HCMV encodes several genes that appear to modulate immune system function. One of these genes, termed US28, is homologous to the mammalian chemokine G-protein coupled receptors (GPCRs). While progress has recently been made in the identification of signaling pathways downstream of US28, very little is known regarding the molecular details proximal to US28 that contribute to the activation of signaling pathways. The objective of this proposal is to identify specific receptor properties and molecular events proximal to US28 that are critical for activation of known signal transduction pathways. We hypothesize that a detailed study of the molecular interactions of betaarrestin proteins with US28 will generate novel insights into the regulation of US28 signaling. The betaarrestins were originally identified in the context of termination of "traditional" G-protein signaling to effectors such as adenylyl cyclases and phospholipases. This termination process, also known as desensitization, involves receptor phosphorylation by GRKs and binding of betarrestin proteins. It is now clear that the betaarrestins simultaneously function as adapter/scaffold molecules to recruit signaling proteins to receptors in order to activate additional "non-traditional" signaling pathways. We have identified a US28 mutant that is unable to interact with betaarrestin and have generated a significant amount of preliminary data regarding signaling from this mutant. We propose to analyze the involvement of betaarrestin proteins in US28 signaling in order to gain a greater understanding of the proximal events leading to activation of US28 signaling pathways. To accomplish this goal, we propose three specific aims. First, we will characterize "traditional" signaling from this US28 mutant in the context of HCMV infection and will analyze how this mutant affects the ability of US28 to stimulate smooth muscle cell migration. Second, we will analyze "non-traditional" signaling pathways from US28 potentially mediated by betaarrestin recruitment to the US28 carboxy terminal regulatory domain. Third, we will analyze US28 signaling in cells deficient for betaarrestin expression in order to specifically define the involvement of betaarrestins. Our preliminary data indicate that US28 engages ?arrestin proteins suggesting that we will be able to make rapid progress toward our goal of defining the role of these important regulatory proteins in US28 signaling. These studies will identify mechanisms regulating US28 mediated signal transduction and will enhance our understanding of how US28 participates in pathogenesis and initiation of HCMV disease.

描述（由申请人提供）：人类巨细胞病毒（HCMV）感染是病毒相关先天性出生缺陷的主要原因，并已被证明是器官移植受者以及艾滋病患者的一个重大公共卫生问题。越来越多的证据表明，HCMV 与血管疾病的发生之间可能存在关联。 HCMV 和免疫系统之间的相互作用是导致疾病发生的关键因素。有趣的是，HCMV 编码了几个似乎可以调节免疫系统功能的基因。这些基因之一称为 US28，与哺乳动物趋化因子 G 蛋白偶联受体 (GPCR) 同源。虽然最近在鉴定 US28 下游信号通路方面取得了进展，但我们对 US28 附近有助于信号通路激活的分子细节知之甚少。该提案的目的是确定 US28 附近的特定受体特性和分子事件，这些特性和分子事件对于激活已知信号转导途径至关重要。我们假设对 betaarrestin 蛋白与 US28 分子相互作用的详细研究将为 US28 信号传导的调节产生新的见解。 β抑制蛋白最初是在终止向腺苷酸环化酶和磷脂酶等效应物发出的“传统”G蛋白信号传导的背景下发现的。这种终止过程也称为脱敏，涉及 GRK 的受体磷酸化和 Betarrestin 蛋白的结合。现在已经清楚，β抑制蛋白同时充当衔接子/支架分子，将信号蛋白募集到受体，从而激活额外的“非传统”信号传导途径。我们已经鉴定出一种无法与 betaarrestin 相互作用的 US28 突变体，并生成了大量有关该突变体信号传导的初步数据。我们建议分析 betaarrestin 蛋白在 US28 信号传导中的参与，以便更好地了解导致 US28 信号传导途径激活的近端事件。为了实现这一目标，我们提出了三个具体目标。首先，我们将在 HCMV 感染的背景下表征来自 US28 突变体的“传统”信号传导，并将分析该突变体如何影响 US28 刺激平滑肌细胞迁移的能力。其次，我们将分析从 US28 可能由 betaarrestin 募集介导的“非传统”信号通路到 US28 羧基末端调节域。第三，我们将分析β抑制蛋白表达缺陷的细胞中的US28信号传导，以便具体定义β抑制蛋白的参与。 我们的初步数据表明，US28 与抑制蛋白结合，这表明我们将能够在确定这些重要调节蛋白在 US28 信号传导中的作用的目标方面取得快速进展。这些研究将确定调节 US28 介导的信号转导的机制，并将增强我们对 US28 如何参与 HCMV 疾病的发病机制和起始的理解。