Molecular Control of IFITM3 in Restricting Influenza Virus Infection

IFITM3 在限制流感病毒感染中的分子控制

• 批准号: 9012283
• 负责人: Jacob Yount
• 金额: $ 36.62万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9012283
• 关键词: Accounting; Antiviral Agents; Biology; Cause of Death; Cellular Membrane; Data; Defect; Development; Drug Targeting; Ensure; Enzymes; Genetic Polymorphism; Health; Human; In Vitro; Infection; Influenza; Integral Membrane Protein; Interferon Activation; Interferons; Knowledge; Mediating; Membrane; Membrane Fluidity; Modification; Molecular; Mus; Natural Immunity; Peptides; Post-Translational Protein Processing; Predisposition; Proteins; Reporting; Research; Resistance; Series; Specificity; Therapeutic; Transmembrane Domain; Ubiquitination; Virus; Virus Diseases; Work; base; combat; cost; fighting; improved; influenzavirus; insight; novel; novel therapeutics; palmitoylation; prevent; research study; trafficking; ubiquitin-protein ligase

 DESCRIPTION (provided by applicant): Influenza virus infection and its complications remains a leading cause of death in the US, and burdens the nation economically with costs of up to $87 billion annually. We, and others, have shown that the interferon- induced transmembrane protein 3 (IFITM3) inhibits influenza virus infections in vitro, and IFITM3 has also been shown to be essential for innate resistance to influenza virus infection in both mice and humans. Despite the importance of IFITM3 in broadly inhibiting influenza and other viruses, this knowledge has not yet inspired new therapeutics because it remains unclear precisely how IFITM3 hinders viral infection and how IFITM3 trafficking and function are regulated biochemically. Our overall hypothesis is that IFITM3 stability and localization are controlled by a series of post-translational modifications that ensure proper delivery and anchoring of IFITM3 to endolysosomes, where its intramembrane domains decrease membrane fluidity to prevent influenza virus fusion/infection. Aim 1 is based on our novel discovery that the E3 ubiquitin ligase NEDD4 is a negative regulator of IFITM3 cellular levels and activity. NEDD4 may represent a novel drug target for improv- ing IFITM3-mediated innate immunity against influenza virus, and our work examining IFITM3 ubiquitination by NEDD4, and the crosstalk between this and other modifications will provide molecular details regarding IFITM3 regulatory mechanisms that must be understood in order to ultimately devise such therapeutics based on IFITM3 biology. Aim 2 is built upon our discovery that a specific DHHC domain-containing palmitoyltransferase is able to palmitoylate IFITM3, which we previously demonstrated is an essential modification necessary for IFITM3 antiviral activity. We will analyze potential IFITM3 palmitoylation defects caused by polymorphisms reported for this enzyme, thus laying the groundwork for its study as an influenza virus susceptibility factor. Our preliminary data also suggest that IFITM3 palmitoylation must occur at a specific cellular compartment for positive effects on its activity to be observed. Thus we will investigate putative DHHC localization mechanisms that account for this effect. This series of experiments will identify critical DHHC trafficking and specificity determinants, and reveal which cellular compartments support the proper palmitoylation/activation of IFITM3. In Aim 3 we will examine the function of IFITM3 intramembrane regions in altering cellular membranes to inhibit virus infections. We have provided evidence that IFITM3's predicted transmembrane domains act instead as intramembrane domains. Intramembrane domains often alter membrane structure, and our preliminary data indicates that IFITM3 indeed decreases membrane fluidity. Thus, we will examine the necessity and sufficiency of IFITM3 intramembrane domains in decreasing membrane fluidity and inhibiting virus infection. In the course of all of these studies we will appy the knowledge gained toward the development of an optimally active but minimally sized antiviral poly- peptide construct. Overall, these research aims should reveal molecular strategies for controlling and exploiting IFITM3 in fighting influenza virus and viral diseases.

 描述（由适用提供）：流感病毒感染及其并发症仍然是美国的主要死亡原因，并且在经济上伯恩斯每年的成本高达870亿美元。我们和其他人表明，干扰素诱导的跨膜蛋白3（IFITM3）抑制了体外影响病毒感染，并且IFITM3也已被证明对于影响小鼠和人类的病毒感染至关重要。尽管IFITM3在广泛抑制影响力和其他病毒中的重要性，但这些知识尚未启发新的疗法，因为它仍然不清楚IFITM3如何阻碍病毒感染以及IFITM3运输和功能如何受到生物化学调节。我们的总体假设是IFITM3的稳定性和定位由 一系列的翻译后修饰，以确保IFITM3向内溶液体的适当递送和锚定，其内膜内结构域可降低膜流动性，从而防止影响力融合/感染。 AIM 1基于我们的新发现，即E3泛素连接酶NEDD4是IFITM3细胞水平和活性的负调节剂。 NEDD4可能代表了改善IFITM3介导的对流感病毒的先天免疫力的新型药物靶标，而我们对NEDD4进行IFITM3泛素化的工作，并且这种修改与其他修改之间的串扰将提供有关IFITM3调节性机制的分子，必须基于IFITM3调节性机制，以最终为基于诸如此类的If Teperics Insivesics opepysicsicissics。 AIM 2建立在我们发现的发现，即具有特定DHHC域的含Palmitoyltransylansferase的特定发现，能够棕榈酰inifitm3，我们先前证明这是IFITM3抗病毒活性所必需的必要修改。我们将分析由该酶报道的多态性引起的潜在IFITM3棕榈酰化缺陷，从而为其研究奠定了基础，作为影响病毒易感因子。我们的初步数据还表明，IFITM3棕榈酰化必须在特定的细胞区室中发生，以观察到其活性的积极影响。我们将调查解释这种效果的推定的DHHC定位机制。这一系列实验将确定关键的DHHC运输和特异性确定词，并揭示哪些细胞室支持适当的棕榈酰化/激活IFITM3。在AIM 3中，我们将检查IFITM3膜内区域在改变细胞膜以抑制病毒感染的功能。我们提供了证据表明IFITM3的预测跨膜域而改为作用。作为膜内结构域。膜内结构域通常会改变膜结构，我们的初步数据表明IFITM3确实降低了膜的流动性。这是，我们将研究IFITM3膜内结构域在降低膜流动性和抑制病毒感染方面的必要和安全性。在所有这些研究的过程中，我们将批准获得最佳活跃但最小尺寸的抗病毒多肽构建的知识。总体而言，这些研究的目的应揭示用于控制和利用IFITM3在战斗影响病毒和病毒疾病中的分子策略。