Integration and Expression of Retrovirus DNA

逆转录病毒DNA的整合和表达

• 批准号: 6616778
• 负责人: JOHN M COFFIN
• 金额: $ 39.63万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6616778
• 关键词: Retroviridae disease; avian leukosis virus; enzyme activity; host organism interaction; integrase; metallothionein; mitochondrial DNA; provirus; tissue /cell culture; virus DNA; virus genetics; virus infection mechanism; virus integration

Integration of viral into host cell DNA is a central and unique feature of retrovirus replication, and is directly responsible for many of the special characteristics of this important group of viruses, including their ability to cause cancer by activating and transducing oncogenes, their evolutionary persistence as endogenous viruses in the host germline, their very broad pathogenic spectrum, and their ability to serve as vectors for the gene therapist. Although the biochemical and structural aspects of the integration process are becoming quite well worked out, many important features remain unknown, including what defines an integration target, the relationship between chromatin and DNA structure and integration specificity, and the effect of the location of the integrated provirus on its subsequent expression. The overall goal of this project is to improve our understanding of key aspects of the role of integration in the virus-host interaction. Specifically, we will address the following questions: 1. Can we define an optimal target sequence (or structure) for integrase in vitro? What are the structural correlates of integrase targeting? How does the intracellular environment affect the use of certain sequences (or structures) as targets? 2. How does the structure, location, and activity of a region of cellular DNA affect its use as an integration target? In particular, we will test the hypothesis, based on our prior work, that integration has no strong regional preference, and that (contrary to prior ideas), increasing transcriptional activity of a gene does not enhance is use as an integration target, but rather reduces it, as a consequence of interference of bound transcription factors. 3. How does integration affect subsequent expression of the provirus. Why is integration apparently required for efficient expression? What is the role of the integration site in the level of transcription of the integrated provirus? In particular, what is the basis for "position effects" leading to clone-to-clone variation in expression of integrated proviruses?

病毒与宿主细胞DNA的整合是逆转录病毒复制的核心和独特特征，并且直接导致了这一重要病毒群的许多特殊特征，包括它们通过激活和转导癌基因而导致癌症的能力，它们作为宿主种系内源性病毒的进化持续性，它们非常广泛的致病谱，以及它们作为基因治疗载体的能力。尽管整合过程的生化和结构方面已经得到了很好的研究，但许多重要的特征仍然未知，包括什么定义了整合靶标，染色质和DNA结构之间的关系以及整合特异性，以及整合前病毒的位置对其随后表达的影响。该项目的总体目标是提高我们对病毒-宿主相互作用中整合作用的关键方面的理解。具体而言，我们将解决以下问题：1。我们能否确定体外整合酶的最佳靶序列（或结构）？整合酶靶向的结构关联是什么？细胞内环境如何影响某些序列（或结构）作为靶标的使用？2. 细胞DNA区域的结构、位置和活性如何影响其作为整合靶标的使用？特别是，我们将测试假设，基于我们之前的工作，整合没有强烈的区域偏好，并且（与先前的想法相反），增加基因的转录活性不会增强其作为整合靶标的使用，而是减少它，作为结合转录因子干扰的结果。3. 整合如何影响原病毒的后续表达。为什么高效表达显然需要整合？整合位点在整合原病毒转录水平中的作用是什么？特别是，导致整合原病毒克隆间表达变异的“位置效应”的基础是什么？