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

• 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
• 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

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.

摘要 人类免疫缺陷病毒（HIV-1）感染可导致致命的疾病获得性免疫缺陷 综合征（艾滋病）。在HIV-1的自然感染过程中，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HIV-1的转录调控 DNA在HIV-1感染和发病中起重要作用。与强大的病毒基因表达 从整合的病毒DNA开始，染色体外的、未整合的病毒DNA转录非常差。的确切 未整合的HIV-1 DNA沉默的机制还不清楚，这构成了一个主要的问题。 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 未整合的HIV-1 DNA通过靶向宿主蛋白质进行降解。在搜索Vpr目标主机因素时， 可以沉默未整合的HIV-1 DNA，我们已经进行了Vpr靶点的CRISPR-Cas9敲除筛选 NS 1BP基因的克隆和鉴定。我们还发现，NS 1BP相互作用的伴侣，SMC 1A/3粘附素复合物， 沉默未整合的HIV-1 DNA所必需的。我们假设NS 1BP作为辅助因子， 病毒DNA上的SMC 1A/3粘附素复合物的负载，导致病毒染色质压缩和基因表达。 抑制和Vpr介导的NS 1BP降解导致粘附素复合物从 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NS 1BP和SMC 1A/3粘附素复合物介导沉默的机制。 未整合的HIV-1 DNA（Aim 1），并阐明Vpr拮抗沉默介导的机制， 通过NS 1BP和cohesin复合物（Aim 2）。我们提出的研究将大大扩展我们对 未整合的HIV-1 DNA转录调控的分子机制，并提供新的 关于HIV-1 DNA的表观遗传沉默的信息。从长远来看，这些研究将提供新的 治疗HIV-1感染的目标和策略。