Regulated Intramembrane Proteolysis of CREB3L1 in Innate Antiviral Response

先天抗病毒反应中 CREB3L1 的调节膜内蛋白水解

• 批准号: 8484343
• 负责人: JIN YE
• 金额: $ 36.99万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-06 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8484343
• 关键词: Accounting; Antiviral Agents; Antiviral Response; Appearance; Binding; Cell Nucleus; Cells; Chronic; Cleaved cell; Cyclic AMP-Responsive DNA-Binding Protein; Drug Targeting; Endoplasmic Reticulum; Family; Gene Targeting; Golgi Apparatus; Hepatitis C; Hepatitis C virus; Human; Immune response; Infection; Interferons; Knowledge; Liver Failure; Mediating; Membrane; Membrane Proteins; Microarray Analysis; Mutation; N-terminal; Names; Pathway interactions; Peptide Hydrolases; Play; Population; Process; Proteins; Proteolysis; RNA Virus Infections; Regulation; Role; Site; Testing; Travel; United States; Viral Proteins; Virus; Virus Diseases; Virus Replication; base; chronic liver disease; drug resistant virus; endoplasmic reticulum stress; hepatoma cell; mutant; novel; public health relevance; site-1 protease; transcription factor

DESCRIPTION (provided by applicant): Hepatitis C virus (HCV) infects 3% of the world population and accounts for most cases of chronic liver disease. In the United States, HCV infection is the leading cause of liver failure. Drugs targeting HCV proteins are difficult to be developed owing to the high rate of mutation during HCV replication that allows quick appearance of the drug-resistant viral strains. The current treatment for HCV infection is based on interferon, which mediates an innate immune response against infection of RNA virus. However, this treatment is only partially effective. Thus, understanding other innate antiviral responses may reveal much needed new strategies to treat HCV infection. We have recently identified a novel innate antiviral response that plays an important role in limiting HCV infection in a line of human hepatoma cells. This pathway is mediated by cAMP response element binding protein 3-like 1 (CREB3L1), the function of which was previously unknown. CREB3L1 belongs to a family of transcription factors that are synthesized as membrane-bound precursors inserted in the endoplasmic reticulum (ER), and activated by a process termed regulated intramembrane proteolysis (RIP). Based on our current understanding of RIP, we propose that replication of HCV in the ER results in cleavage of CREB3L1 by Site-1 protease (S1P) and Site-2 protease (S2P). The proteolytic cleavage allows the NH2-terminal fragment of CREB3L1 to be released from the membrane and travel to the nucleus to activate its target genes involved in antiviral responses. These hypotheses will be tested by three specific aims raised in the proposal. Specific Aim 1 will determine the mechanism by which HCV replication stimulates the cleavage of CREB3L1. We will examine whether ER stress induced by expression of HCV- encoded membrane proteins triggers the cleavage of CREB3L1. Specific Aim 2 will determine whether S1P and S2P-catalyzed cleavages of CREB3L1 is required for its antiviral function. The primary approach is to make CREB3L1 mutants that cannot be cleaved by these proteases and examine the effect of the mutations on its antiviral function. Specific Aim 3 will identify the CREB3L1 target genes that inhibit HCV replication by microarray analysis. If these specific aims are achieved, we will have contributed novel information that will significantly enhance our understanding of the innate immune response. This new knowledge may reveal novel drug targets to treat HCV infection.

描述（由申请人提供）：丙型肝炎病毒（HCV）感染了3％的世界人口，并占大多数慢性肝病。在美国，HCV感染是肝衰竭的主要原因。靶向HCV蛋白的药物由于在HCV复制过程中的突变速率高而难以开发，从而可以快速出现药物抗药性病毒菌株。 HCV感染的当前治疗方法基于干扰素，该干扰素介导了针对RNA病毒感染的先天免疫反应。但是，这种治疗仅部分有效。因此，了解其他先天抗病毒反应可能会揭示急需的新策略来治疗HCV感染。 我们最近确定了一种新型的先天抗病毒反应，该反应在限制人类肝癌细胞的HCV感染中起着重要作用。该途径是由CAMP响应元件结合蛋白3样1（CREB3L1）介导的，该途径以前未知。 CREB3L1属于一个转录因子家族，这些因子被合成为内质网中插入的膜结合前体（ER），并被称为被称为受调节内膜内蛋白水解（RIP）的过程激活。基于我们目前对RIP的理解，我们建议在ER中复制HCV会导致site-1蛋白酶（S1P）和Site-2蛋白酶（S2P）裂解CREB3L1。蛋白水解裂解使CREB3L1的NH2末端片段从膜中释放出来，然后前往细胞核以激活其涉及抗病毒反应的靶基因。 这些假设将通过提案中提出的三个特定目标来检验。具体目标1将确定HCV复制刺激CREB3L1的裂解的机制。我们将检查HCV编码的膜蛋白表达引起的ER应激是否触发CREB3L1的裂解。具体的目标2将确定CREB3L1的S1P和S2P催化的裂解是否需要其抗病毒功能。主要的方法是使不能被这些蛋白酶裂解的CREB3L1突变体，并检查突变对其抗病毒功能的影响。特定的目标3将确定通过微阵列分析抑制HCV复制的CREB3L1靶基因。如果实现这些特定目标，我们将贡献新的信息，从而大大增强我们对先天免疫反应的理解。这种新知识可能揭示了治疗HCV感染的新型药物靶标。