SMC1A/3 cohesin complex-mediated silencing of unintegrated HIV-1 DNA and the antagonism by Vpr

SMC1A/3粘连蛋白复合物介导的未整合HIV-1 DNA的沉默和Vpr的拮抗作用

基本信息

批准号：
10760648
负责人：
Yiping Zhu
金额：
$ 23.1万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-08-16 至 2025-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10760648
关键词：
ATP phosphohydrolase Acquired Immunodeficiency Syndrome Adopted Binding CRISPR/Cas technology CSPG6 gene Cell Nucleus Cells Chromatin Chromatin Structure Complex Cytoplasm DNA DNA Integration Disease Dissociation Epigenetic Process Euchromatin Gene Expression Genes Genetic Transcription Genome Goals HIV Heterochromatin Histones Host Defense Human T-lymphotropic virus 1 Individual Infection Inherited Integration Host Factors Intestines Invaded Knock-out Knowledge Maintenance Mediating Molecular Physical condensation Play Primate Lentiviruses Research Resources Role Structure System T-Lymphocyte Taxes Testing Transcriptional Activation Transcriptional Regulation Viral Viral Genes Viral Pathogenesis Viral Proteins Virus Virus Diseases Virus Integration Virus Replication antagonist co-infection cofactor cohesin epigenetic silencing microbial protein degradation screening viral DNA viral transmission vpr Gene Products

项目摘要

ABSTRACT Human immunodeficiency virus (HIV-1) infection can lead to the deadly disease acquired immunodeficiency syndrome (AIDS). During the natural infection of HIV-1, some viral DNAs are integrated into host genome, but the vast majority of viral DNAs exist in an unintegrated state. Transcriptional regulation of unintegrated HIV-1 DNA plays important roles in HIV-1 infection and pathogenesis. In contrast to the robust viral gene expression from integrated viral DNA, the extrachromosomal, unintegrated viral DNAs are very poorly transcribed. The exact mechanisms for the silencing of unintegrated HIV-1 DNA are not well understood, which constitutes a major knowledge gap in HIV-1 research. HIV-1 accessory protein Vpr enhances viral gene expression from unintegrated HIV-1 DNA by targeting host proteins for degradation. In search for Vpr target host factor(s) that can silence unintegrated HIV-1 DNA, we have performed a CRISPR-Cas9 knockout screening of Vpr target genes and identified NS1BP. We also found that NS1BP-interacting partner, the SMC1A/3 cohesin complex, is required for the silencing of unintegrated HIV-1 DNA. We hypothesize that NS1BP acts as a cofactor to facilitate the loading of the SMC1A/3 cohesin complex on viral DNA, which results in viral chromatin compaction and gene suppression, and Vpr-mediated degradation of NS1BP results in the dissociation of the cohesin complex from viral DNA, which consequently depresses the silencing of unintegrated HIV-1 DNA. In this project, we will determine the mechanism by which NS1BP and the SMC1A/3 cohesin complex mediate the silencing of unintegrated HIV-1 DNA (Aim 1), and elucidate the mechanism by which Vpr antagonizes the silencing mediated by NS1BP and the cohesin complex (Aim 2). Our proposed studies will significantly extend our understanding of the molecular mechanism for the transcriptional regulation of unintegrated HIV-1 DNA and provide new information regarding the epigenetic silencing of HIV-1 DNA. In the long term, these studies will provide new targets and strategies for the cure of HIV-1 infection.

抽象的人类免疫缺陷病毒（HIV-1）感染可导致致命的获得性免疫缺陷病综合症（艾滋病）。在 HIV-1 自然感染过程中，一些病毒 DNA 整合到宿主基因组中，但绝大多数病毒DNA以未整合的状态存在。未整合的 HIV-1 的转录调控 DNA 在 HIV-1 感染和发病机制中发挥着重要作用。与强大的病毒基因表达相反与整合的病毒 DNA 相比，染色体外、未整合的病毒 DNA 的转录效果非常差。确切的未整合的 HIV-1 DNA 沉默机制尚不清楚，这构成了一个主要的 HIV-1 研究中的知识差距。 HIV-1辅助蛋白Vpr增强病毒基因表达通过靶向宿主蛋白进行降解来去除未整合的 HIV-1 DNA。在寻找 Vpr 目标宿主因素时可以沉默未整合的HIV-1 DNA，我们对Vpr靶点进行了CRISPR-Cas9敲除筛选基因并鉴定出 NS1BP。我们还发现 NS1BP 相互作用伙伴 SMC1A/3 粘连蛋白复合物沉默未整合的 HIV-1 DNA 所需的。我们假设 NS1BP 作为辅助因子来促进将 SMC1A/3 粘连蛋白复合物装载到病毒 DNA 上，从而导致病毒染色质压缩和基因 NS1BP 的抑制和 Vpr 介导的降解导致粘连蛋白复合物从病毒 DNA，从而抑制未整合的 HIV-1 DNA 的沉默。在这个项目中，我们将确定 NS1BP 和 SMC1A/3 粘连蛋白复合物介导沉默的机制未整合的 HIV-1 DNA（目标 1），并阐明 Vpr 拮抗沉默介导的机制由 NS1BP 和粘连蛋白复合物组成（目标 2）。我们提出的研究将显着扩展我们对未整合的HIV-1 DNA转录调控的分子机制并提供新的有关 HIV-1 DNA 表观遗传沉默的信息。从长远来看，这些研究将提供新的治愈 HIV-1 感染的目标和策略。